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  • 1985-1989  (83)
  • 1975-1979  (51)
  • 1960-1964  (15)
  • 1910-1914
  • 1890-1899
  • Phosphorus
  • Synthetic methods
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Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Phosphorus fertilizer response in narrow-leafed lupin (Lupinus angustifolius L.) and chickpea (Cicer arietinum) compared to wheat (Triticum aestivum) in early growth (1989)
    Springer
    Nutrient cycling in agroecosystems 19 (1989), S. 1-6 
    Details
    ISSN: 1573-0867
    Keywords: Phosphorus ; lupin ; chickpea ; wheat ; nodulation ; dry matter production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A glasshouse experiment was conducted to examine the comparative growth and P uptake response following P fertilizer application in lupins (Lupinus angustifolius L. cv. Chittick) and chickpeas (Cicer arietinum cv. Tyson) compared to wheat (Triticum aestivum cv. Sunstar). Measurements of dry matter, phosphorus uptake and nodule numbers were made at 50 and 100 days after sowing. At the 50 day harvest, the two legume crops produced less dry matter and accumulated less plant P than wheat but no such species interactions were present at the 100 day harvest. Chickpeas showed strong positive responses in nodule numbers with increasing rates of P fertilizer while such effects were less and more variable with lupins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01080679
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  • 2
    Electronic Resource
    Electronic Resource
    Phosphorus transport to the bottom of Lake Constance (1989)
    Springer
    Aquatic sciences 51 (1989), S. 181-191 
    Details
    ISSN: 1420-9055
    Keywords: Phosphorus ; sedimentation ; Lake Constance ; particles ; calcite POM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Despite decreasing nutrient loading of Lake Constance over the past few years, annual sedimentation rates of dry matter remained nearly constant at a level of about 1000 gm−2y−1. The phosphorus content in settling material varied between 0.13 and 0.22% of dry weight. Phosphorus was transported to the lake bottom mainly by POM and by coprecipitation with authigenically formed calcite (estimated from results of laboratory studies). Adsorption to sinking particles of allochthonous origin was of minor importance. The effect of a self-cleaning mechanism is discussed with regard to continuously declining contents of dissolved phosphorus in Lake Constance since 1981, due to external sanitation measures in the drainage area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877741
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  • 3
    Electronic Resource
    Electronic Resource
    Statistical models for the estimation of net phosphorus sedimentation in lakes (1989)
    Springer
    Aquatic sciences 51 (1989), S. 192-210 
    Details
    ISSN: 1420-9055
    Keywords: Phosphorus ; mass-balance models ; sedimentation ; error propagation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The empirical adequacy of four phosphorus mass-balance models is evaluated with respect to how the prediction error variance of the corresponding net sedimentation parameters is propagated in the steadystate equations. Using the criterion of minimum propagation error variance (PEV), different groups of lakes can be distinguished for which different empirical equations are used to predict net phosphorus sedimentation. The classification reduced prediction error significantly and also reflected different patterns of sedimentation. Application of this criterion to time-series of individual lakes shows that it is possible to determine a priori whether net annual sedimentation will be better correlated to the annual loading or to the lake content. The correlations depended also on the load/lake content ratio, suggesting that net sedimentation is best viewed as the sum of the partial sedimentation of the load and of the partial sedimentation of the lake content. On average, 25% of the load and 18% of the lake content are sedimented annually. Viewing net phosphorus sedimentation as a function of both the load and the lake content can also explain and predict the well-known cross-sectional correlation between phosphorus retention and water residence time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877742
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  • 4
    Electronic Resource
    Electronic Resource
    The chemical composition of pine foliage in relation to the population dynamics of the pine beauty moth, Panolis flammea, in Scotland (1989)
    Springer
    Oecologia 78 (1989), S. 251-258 
    Details
    ISSN: 1432-1939
    Keywords: Panolis flammea ; Pinus ; Nitrogen ; Phosphorus ; Tannins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper reports part of a study to determine why damaging outbreaks of the pine beauty moth, Panolis flammea (D & S) (Lepidoptera: Noctuidae), in Scotland are frequent on lodgepole pine but do not occur on Scots pine, and why outbreaks on lodgepole pine are mainly confined to trees growing in deep unflushed peat. The elongation of shoots and the growth of needles of Scots pine occurred later in the season than did those of lodgepole pine. The foliage of Scots pine generally had a higher level of nitrogen, and consistently had a higher level of phosporus, but had a consistently lower level of tannins than that of lodgepole pine during the period when the larvae were feeding each year. The nitrogen content of the foliage of lodgepole pine growing in an iron pan soil was generally higher than that of lodgepole pine growing in deep peat during the same period but there were no general differences in the phosphorus or tannin contents of lodgepole pine in the 2 soil types. These findings suggest that Scots pine is a more suitable host plant than lodgepole pine and that the foliage of lodgepole pine growing in deep peat is not more suitable than lodgepole pine growing in an iron pan soil. On the basis of the chemical analyses used in this study, it is concluded that the abundance of pine beauty moth in Scotland is not strongly influenced by the nutritional suitability of its host plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377163
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  • 5
    Electronic Resource
    Electronic Resource
    Physiological determinants of growth rate in response to phosphorus supply in wild and cultivated Hordeum species (1989)
    Springer
    Oecologia 79 (1989), S. 96-105 
    Details
    ISSN: 1432-1939
    Keywords: Allocation ; Growth ; Phosphorus ; Photosynthesis ; Seed size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Under favorable nutrition, accessions of the weedy barleygrass (Hordeum leporinum and H. glaucum) had a higher relative growth rate (RGR) than did accessions of cultivated barley (H. vulgare) or its wild progenitor (H. spontaneum). RGR was not positively correlated with the presumed level of soil fertility at the collection site of an accession either within or among species. RGR was reduced more strongly by low-P supply in the progenitor than in the crop or weed, indicating that selection of cultivars to grow in fertile soils had not reduced their potential to grow effectively under low-P conditions. Seed and embryo masses were more important than RGR in determining plant size. Relative differences among assessions in plant size declined with time, because (1) accessions with small seeds had a higher RGR, and (2) RGR of large-seeded accessions declined with time. Absolute growth rate correlated positively with leaf area and negatively with photosynthetic rate per unit leaf area. Under favorable nutrition, maximum photosynthetic rate correlated negatively with leaf length and therefore was higher in the weeds than in the crop or progenitor accessions. P absorption potential did not differ consistently among species but generally increased in response to P stress. Cultivars produced a few tall tillers, whereas weeds and progenitors produced many small tillers. The cultivar had a larger proportion of reproductive tillers, allocated a larger proportion of biomass to grain, and produced larger grains than did the weedy accession. By contrast, the weed began maturing seeds sooner, produced more reproductive tillers, and produced more grains per car and per plant than did the cultivar. The study suggests two major conclusions: (1) A low RGR is not an adaptation to low P supply in annual Hordeum species. (2) Seed size is the major determinant of early plant size between accessions in these Hordeum species under favorable nutrition. However, large seed size indirectly results in a low RGR because of the inverse relationship between plant size and RGR and results in a low photosynthetic rate because of the inverse relationship between leaf size and photosynthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378245
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  • 6
    Electronic Resource
    Electronic Resource
    Long-term depletion of calcium and other nutrients in eastern US forests (1989)
    Springer
    Environmental management 13 (1989), S. 593-601 
    Details
    ISSN: 1432-1009
    Keywords: Acid precipitation ; Biomass nutrients ; Calcium ; Clearcutting ; Magnesium ; Nitrogen ; Phosphorus ; Potassium ; Soil leaching ; Soil nutrients ; Timber harvest ; Weathering ; Whole-tree harvest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Both harvest removal and leaching losses can deplete nutrient capital in forests, but their combined long-term effects have not been assessed previously. We estimated changes in total soil and biomass N, Ca, K, Mg, and P over 120 years from published data for a spruce-fir site in Maine, two northern hardwood sites in New Hampshire, central hardwood sites in Connecticut and Tennessee, and a loblolly pine site in Tennessee. For N, atmospheric inputs counterbalance the outputs, and there is little long-term change on most sites. For K, Mg, and P, the total pool may decrease by 2%–10% in 120 years depending on site and harvest intensity. For Ca, net leaching loss is 4–16 kg/ha/yr in mature forests, and whole-tree harvest removes 200–1100 kg/ha. Such leaching loss and harvest removal could reduce total soil and biomass Ca by 20%–60% in only 120 years. We estimated unmeasured Ca inputs from rock breakdown, root-zone deepening, and dry deposition; these should not be expected to make up the Ca deficit. Acid precipitation may be the cause of current high leaching of Ca. Although Ca deficiency does not generally occur now in acid forest soils, it seems likely if anthropogenic leaching and intensive harvest removal continue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01874965
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  • 7
    Electronic Resource
    Electronic Resource
    Localization of calcium and phosphorus in early predentin-matrix components by electron spectroscopic imaging (ESI)-analysis in rat molars (1989)
    Springer
    Cell & tissue research 255 (1989), S. 611-617 
    Details
    ISSN: 1432-0878
    Keywords: Mantle dentin matrix ; Electron spectroscopic imaging (ESI)-analysis ; Calcium ; Phosphorus ; Dentinogenesis ; Biomineralization ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subcellular distribution of the inorganic elements calcium (Ca) and phosphorus (P) was studied in the first-formed dentin matrix during initial mineralization in neonatal rat molars. This most peripheral matrix region is comprised of a proteoglycan-rich ground substance, interwoven by a collagenous network, matrix vesicles, aperiodic fibrils derived from the dental basal lamina, and apical odontoblastic cell processes. All matrix components may possibly serve as templets for mineral deposition during initial calcification of first-formed mantle dentin and predentin. By means of the very sensitive ESI-analysis we studied the subcellular localization of Ca and P and their possible association with distinct organic extracellular matrix components and odontoblasts. Ca-signals were found in the ground substance, at striated collagen fibrils and plasma membranes of odontoblasts in the cuspal early matrix region, but occurred only sparsely in the ground substance of the more distal matrix region where odontoblast processes attach to aperiodic fibrils of the dental basal lamina. Ca was generally absent in matrix vesicles. In contrast, P-signals were found in matrix vesicles, at aperiodic fibrils and at the plasma membranes of odontoblasts. Ca and P co-localized at striated collagen fibrils (type I or II). These results suggest that striated collagen fibrils might serve as primary deposition sites for calcium phosphate during early biological calcification of organic extracellular macromolecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218798
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  • 8
    Electronic Resource
    Electronic Resource
    Environmental modulation of calcium and phosphorus metabolism in embryonic snapping turtles (Chelydra serpentina) (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 501-508 
    Details
    ISSN: 1432-136X
    Keywords: Calcium ; Embryos ; Phosphorus ; Turtles ; Water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Eggs of common snapping turtles (Chelydra serpentina) were incubated on wet (−150 kPa water potential) and dry (−950 kPa) substrates in a laboratory study assessing the effects of the hydric environment on patterns of mobilization of calcium and phosphorus by developing embryos. We found that embryos developing in wet environments withdrew nutrients from their yolk faster, grew more rapidly, and incubated longer than embryos exposed to dry environments. Turtles developing in both environments absorbed calcium from the yolk at similar rates and depleted the yolk of almost its entire reserve of calcium prior to hatching. Calcium withdrawn from the yolk was supplemented with calcium mobilized from the eggshell, but embryos in wet environments obtained substantially more calcium from the eggshell than did those in dry settings. Embryos obtained all of the phosphorus used in skeletogenesis from the yolk, but those incubating in wet environments mobilized phosphorus from this compartment more rapidly than did those in dry settings. Exposing embryonic snapping turtles to wet environments apparently allows them to make more efficient use of the transitory source of calcium in the eggshell than is possible in dry environments. However, the residual yolk in hatchlings from both wet and dry environments contains too little calcium to support the growth of hard and soft tissues in neonates at rates similar to those characterizing the growth phase of development in embryogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692422
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  • 9
    Electronic Resource
    Electronic Resource
    Intramolecular, Stoichiometric (Li, Mg, Zn) and Catalytic (Ni, Pd, Pt) Metallo-Ene Reactions in Organic Synthesis [New Synthetic Methods (75)]Dedicated to Professor Elias J. Corey on the occasion of his 60th birthday (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 28 (1989), S. 38-52 
    Details
    ISSN: 0570-0833
    Keywords: Metallo-ene reaction ; Ene reaction ; Synthetic methods ; Catalysis ; Natural products ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metallo-ene reactions, hardly recognized until very recently, have experienced a breathtaking development when applied in an intramolecular sense. Efficient regio- and stereoselective magnesium-ene cyclizations have served as a cornerstone for numerous syntheses of structurally diverse natural products (e.g., sesquiterpenes of marine or plant origin, alkaloids, fragrances, insect defense compounds, and a fungitoxin). A brilliant example is the synthesis of the elusive odorant (+)-khusimone which outshines 20 years of work in the field of tricyclovetivane synthesis. Palladium-, platinum-, and nickel-catalyzed versions of the metallo-ene reaction are in a comparatively early stage of exploration, but, nevertheless, reveal intriguing potential. Hence an almost 100% stereospecific C—O→C—;Pd-→ C—C chirality transfer permits simple and selective, cis- or trans-annelation processes. The mild cyclization conditions are compatible with various functional groups, such as nitrogen moieties, which offer interesting perspectives for the preparation of heterocycles (e.g., alkaloids) difficult to obtain by other methods. Carbon monoxide insertion reactions of the cyclized σ-metal intermediates were shown to afford annelated cyclopentanones and cyclopentenones with concomitant stereocontrolled formation of four carbon-carbon bonds. These and other observations, highlighted in this article, provide a platform for further extensions and applications of this powerful method in organic synthesis.
    Additional Material: 11 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198900381
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  • 10
    Electronic Resource
    Electronic Resource
    Gene Synthesis [New Synthetic Methods (77)]Dedicated to Professor Hansgeorg Gareis on the occasion of his 60th birthday (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 28 (1989), S. 716-734 
    Details
    ISSN: 0570-0833
    Keywords: Gene technology ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oligonucleotide synthesis, until a few years ago the rather exotic preserve of a few experts, has become an integral part of the arsenal of molecular-biological techniques. The last decade, in particular, has seen unbelievably rapid development in this area. DNA synthesis has been automated and can now produce genes greater than 1000 base pairs in length. Tailor-made synthetic genes also permit the synthesis of altered or even novel proteins (de novo protein design) by gene-technological methods. Together with modern methods of gene isolation, sequencing, and expression, gene synthesis has played a major part in the enormous advances achieved in gene technology.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198907161
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  • 11
    Electronic Resource
    Electronic Resource
    Cyclizations via Palladium-Catalyzed Allylic Alkylations [New Synthetic Methods (79)] (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 28 (1989), S. 1173-1192 
    Details
    ISSN: 0570-0833
    Keywords: Cyclization ; Allylic alkylation ; Alkylation ; Synthetic methods ; Palladium ; Catalysis ; C-C coupling ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The history of ring systems in organic chemistry parallels their synthetic accessibility. Transition-metal-catalyzed cyclizations offer a new opportunity to create carbo- and heterocyclic compounds with great facility. Among these methods, allylic alkylations catalyzed by palladium have proven unusually productive because of the extraordinary chemo-, regio-, and diastereoselectivity and the continuing possibility for the development of enantioselectivity. The rules for ring closure differ from those for non-transition-metal-catalyzed reactions. A major benefit is the ability to generate medium (eight-, nine-, ten-, and eleven-membered) and large rings in preference to normal (five-, six- and seven-membered) rings. With the appropriate substrate, efficient macrocyclizations are possible under conditions of normal concentrations. A second major benefit derives from the complementary stereochemistry of the metalcatalyzed substitution (net retention of configuration) compared to non-metal-catalyzed reactions (inversion of configuration). Further, the requirement for the substrate to conform to the transition-metal template may impose a stereochemical preference in the intermediate that ultimately translates into the thermodynamically less stable organic product regardless of the stereochemistry of the starting material. While more work has focused on carbocyclic synthesis, the possibilities for heterocyclic synthesis are just beginning to be tapped. In addition to forming heterocycles by C—C bond formation, use of a heteroatom as a nucleophile has already proven effective for oxygen and nitrogen, with other nucleophiles awaiting investigation. New dimensions for cyclization via allylic alkylation arise by generating the requisite π-allylpalladium intermediates by methods other than palladium(0)-initiated allylic ionizations. In addition, metals other than palladium will clearly expand the possibilities, but as yet remain untapped.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198911731
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  • 12
    Electronic Resource
    Electronic Resource
    General Aspects and Optimization of Enantioselective Biocatalysis in Organic Solvents: The Use of Lipases [New Synthetic Methods (76)] (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 28 (1989), S. 695-707 
    Details
    ISSN: 0570-0833
    Keywords: Enantioselectivity ; Lipases ; Synthetic methods ; Enzyme catalysis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enantioselective biocatalysis in nonaqueous media is becoming increasingly important in preparative synthetic chemistry. This article discusses (1) the general catalytic properties of enzymes in nonaqueous environments, (2) the basic principles that govern lipase-catalyzed enantioselective esterification and transesterification reactions in organic media for the preparation of optically active acids and alcohols, (3) the determination of kinetic and thermodynamic parameters, and (4) the quantitative analysis of published data.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198906951
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  • 13
    Electronic Resource
    Electronic Resource
    The Stereoselectivity of Intermolecular Free Radical Reactions [New Synthetic Methods (78)]Dedicated to Professor Christoph Rüchardt on the occasion of his 60th birthday (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 28 (1989), S. 969-980 
    Details
    ISSN: 0570-0833
    Keywords: Stereoselectivity ; Reaction mechanisms ; Synthetic methods ; Free radicals ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The regio- and chemoselectivities of free radical reactions are often high and largely predictable; systematic studies have now shown that the stereoselectivity of free radical reactions can also be directed. Examples involving five- and six-membered cyclic radicals will be used to show how steric and stereoelectronic effects influence the diastereoselectivity of reactions of cyclic radicals with olefins. The temperature, the solvent, and the nature of the radical scavenger used also play a role, so that, if the correct reaction conditions are used, the stereoselectivity of reactions for cyclic reactants can be very high. Lower stereoselectivities are often observed for reactions between acyclic radicals and acyclic alkenes. However, preliminary experiments have indicated that under certain conditions such systems can also react in a stereoselective manner.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198909693
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  • 14
    Electronic Resource
    Electronic Resource
    Influence of phenamiphos on the vesicular-arbuscular mycorrhizal symbiosis in Leucaena leucocephala (1988)
    Springer
    Biology and fertility of soils 5 (1988), S. 313-316 
    Details
    ISSN: 1432-0789
    Keywords: Nematicide ; Phosphorus ; Subleaflet P ; Tropeptic Eutrustox ; Leucaena leucocephala ; VA mycorrhiza ; Glomus aggregatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Concentrations of phenamiphos ranging from 0 to 40 μrg/g soil were established in a typical Oxisol (Tropeptic Eutrustox), inoculated or uninoculated with Glomus aggregatum. The effect of the nematicide on the development of vesicular-arbuscular mycorrhizal (VAM) symbiosis was evaluated in the greenhouse using Leucaena leucocephala as an indicator host plant. Treatment of soil with phenamiphos did not have a significant influence on the development of mycorrhizal activity measured in terms of subleaflet phosphorus concentrations. Similarly, the nematicide did not have an adverse effect on the level of mycorrhizal colonization or on the P content of shoots, as determined at the time of harvest. However, shoot dry weight was adversely influenced by phenamiphos when the chemical was applied to the uninoculated soil at 20 μg/g soil or higher, and when it was applied to the inoculated soil at 40 μg/g soil. It is concluded that phenamiphos is not likely to influence the growth of Leucaena or its symbiotic association with VAM fungi if the concentrations applied do not exceed levels known to suppress nematodes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00262138
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  • 15
    Electronic Resource
    Electronic Resource
    Calcium and inorganic phosphate secretion of rat ileum in vitro (1988)
    Springer
    Research in experimental medicine 188 (1988), S. 139-149 
    Details
    ISSN: 1433-8580
    Keywords: Intestinal transport ; 1,25 (OH)2D3 ; Calcium ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The unidirectional ileal transport of calcium (Ca) and inorganic phosphorus (Pi) of rats was measured in vitro with the modified Ussing technique. Animal preparation included 5/6 nephrectomy and EHDP treatment. They were compared to controls as well as to 1,25 (OH)2D3 supplemented rats. The results show that the ileum is a secretory organ for Ca and Pi, the serosa to mucosa transport (Jsm) exceeds the mucosa to serosa transport (Jms). Ca and Pi transport in sm direction is 1,25 (OH)2D3 independent but exhibits a mutual strong correlation. Our observations together with published data are in favor of mainly paracellular, non electrogenic sm transport of both ions. However, the factor controlling sm transport of Ca and Pi remains unidentified. The mucosa to serosa transport (Jms) in the ileum is low for both ions. Ca ms is stimulated by 1,25 (OH)2D3, Pi ms is unchanged.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01852270
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  • 16
    Electronic Resource
    Electronic Resource
    Differences in carbon and nutrient fractions among arctic growth forms (1988)
    Springer
    Oecologia 77 (1988), S. 506-514 
    Details
    ISSN: 1432-1939
    Keywords: Carbohydrate ; Growth form ; Nitrogen ; Phosphorus ; Tundra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In a survey of 28 plant species of 6 major growth forms from Alaskan tundra, we found no consistent difference among growth forms in the chemical nature of stored reserves except for lichens and mosses (which stored C primarily as polysaccharides) and shrubs (which tended to store C more as sugars than as polysaccharides). Forbs and graminoids showed particularly great diversity in the chemical nature of stored reserves. In contrast, C, N, and P chemistry of leaves was strikingly similar among all species and growth forms. Concentrations of stored reserves of C, N, and P were highest and showed greatest seasonal fluctuations in forbs and graminoids but were relatively constant in evergreen shrubs. From this information, we draw three general conclusions: (1) the photosynthetic function of leaves strongly constrains leaf chemistry so that similar chemical composition is found in all species and growth forms: (2) the chemical nature of storage reserves is highly variable, both within and among growth forms; (3) the concentration and seasonal pattern of storage reserves are closely linked to growth-form and reflect growth-form differences in woodiness, phenology, and relative dependence upon concurrent uptake vs. storage in support of growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377266
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  • 17
    Electronic Resource
    Electronic Resource
    Role of phosphorus and nitrogen in photosynthetic and whole plant carbon gain and nutrient use efficiency in eastern white pine (1988)
    Springer
    Oecologia 77 (1988), S. 25-33 
    Details
    ISSN: 1432-1939
    Keywords: Photosynthesis ; Nitrogen ; Phosphorus ; Nutrient use efficiency ; Pinus strobus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In white pine (Pinus strobus) seedlings grown in five forest soils from New York State, net photosynthetic capacity (Amax) plant-1 was correlated with total foliar N plant-1 (r 2=0.57), but was more highly correlated with total foliar P plant-1 (r 2=0.82). There was no relationship (r 2〈0.01) between Amax [g leaf]-1 and foliar N [g leaf]-1 for the pooled data set, but there was a significant (P〈0.001), but weak (r 2=0.20) positive relationship between Amax [g leaf]-1 and foliar P [g leaf]-1 across all soils. However, within two of the five soils leaf N concentration was a significant (P〈0.05) determinant of photosynthetic capacity. Due to differences in soil nutrient availabilities a large range in foliar P:N ratio (0.02–0.15) was observed, and the proportion of leaf P:N appeared to control Amax [g leaf N]-1. Whole plant nitrogen (NUE) and phosphorus (PUE) use efficiencies were well correlated with whole plant P:N ratio. In addition, NUE was well correlated with Amax [g leaf N]-1 and PUE was well correlated with Amax [g leaf P]-1. However, NUE was not well correlated with PUE, and Amax [g leaf N]-1 was not well correlated with Amax [g leaf P]-1. These results indicated that P and/or N limitations were important components of photosynthetic nutrient relations in white pine grown in these five soils and suggest that both P and N and their proportions should be considered in analyses of photosynthesis-nutrient relations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00380920
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  • 18
    Electronic Resource
    Electronic Resource
    Eutrophication of Buttermilk Bay, a cape cod coastal embayment: Concentrations of nutrients and watershed nutrient budgets (1988)
    Springer
    Environmental management 12 (1988), S. 539-553 
    Details
    ISSN: 1432-1009
    Keywords: Coastal embayments ; Eutrophication ; Nitrogen ; Phosphorus ; Coastal lagoons ; Groundwater ; Septic tanks ; Nutrient loading
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nutrient concentrations in Buttermilk Bay, a coastal embayment on the northern end of Buzzards Bay, MA, are higher in the nearshore where salinities are lower. This pattern suggests that freshwater sources may contribute significantly to nutrient inputs into Buttermilk Bay. To evaluate the relative importance of the various sources we estimated inputs of nutrients by each major source into the watershed and into the bay itself. Septic systems contributed about 40% of the nitrogen and phosphorus entering the watershed, with precipitation and fertilizer use adding the remainder. Groundwater transported over 85% of the nitrogen and 75% of the phosphorus entering the bay. Most nutrients entering the watershed failed to reach the bay; uptake by forests, soils, denitrification, and adsorption intercepted two-thirds of the nitrogen and nine-tenths of the phosphorus that entered the watershed. The nutrients that did reach the bay most likely originated from subsoil injections into groundwater by septic tanks, plus some leaching of fertilizers. Buttermilk Bay water has relatively low nutrient concentrations, probably because of uptake of nutrients by macrophytes and because of relatively rapid tidal flushing. Annual budgets of nutrients entering the watershed showed a low nitrogen-to-phosphorus ratio of 6, but passage of nutrients through the watershed raised N/P to 23, probably because of adsorption of PO4 during transit. The N/P ratio of water that leaves the watershed and presumably enters the bay is probably high enough to maintain active growth of nitrogenlimited coastal producers. There is a seasonal shift in N/P in the water column of Buttermilk Bay. N/P exceeded the 16∶1 Redfield ratio during midwinter; the remainder of the year N/P fell below 16∶1. This suggests that annual budgets do not provide sufficiently detailed data with which to interpret nutrient-limitation of producers. Further, some idea of water turnover is also needed to evaluate impact of loading rates. Urbanization of watersheds seems to increase loadings to nearshore environments, and to shift the nutrient loadings delivered to coastal waters to relatively high N-to-P ratios, potentially stimulating growth of nitrogen-limited primary producers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01873266
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  • 19
    Electronic Resource
    Electronic Resource
    Phosphorus and pH relationships in an andic soil with surface and incorporated organic amendments (1988)
    Springer
    Plant and soil 107 (1988), S. 273-278 
    Details
    ISSN: 1573-5036
    Keywords: available P. organic amendments ; pH ; Phosphorus ; residue management Volcanic ash-influenced soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Mission silt loam, (coarse-silty, mixed frigid Andic Fragiochrepts) is a forest soil in the Pacific Northwest which has a weathered ash horizon derived from volcanic eruptions in the Cascade Mountain Range. The major production problem for this soil is P fixation due to the weathered volcanic ash. Alternatives to large additions of fertilizer P are considered important in management of this and related soils. The objective of this work was to study the infuence of organic amendments on soil pH and extractable P in Mission soil. Alfalfa, (Medicago sativa L.) mixed conifer bark or sawdust was added at 4.8% w/w soil as a surface or incorporated treatment. In incubation experiments, both extractable P and soil pH were significantly increased over time for both surface and incorporated amendments. The majority of P mineralized from surface applied alfalfa remained in the surface 0–2 cm of the soil regardless of incubation period. Conversely, a uniform increase in P occurred throughout the 18 cm soil depth when sawdust was surface applied. The change in extractable P with sawdust addition was equivalent to 61 mg P kg−1 soil as soluble inorganic material. Soil pH increased rapidly in proximity to surface applied alfalfa while bark and sawdust affected the soil increasingly with time regardless of placement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02370557
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  • 20
    Electronic Resource
    Electronic Resource
    Specific activity measurements to determine phosphorus turnover in bluegill, Lepomis macrochirus (1988)
    Springer
    Hydrobiologia 157 (1988), S. 3-11 
    Details
    ISSN: 1573-5117
    Keywords: Phosphorus ; P-32 ; bluegill ; biological turnover constant ; radioactive tracer study ; specific activity measurements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The biological turnover constant for phosphorus was determined in muscle and five other sections of bluegill. Bluegill of average weight 121 g were maintained in a large flowthrough system at 22°–16°C and fed worms, Eisenia foetida, at two feeding levels, ad lib. (which averaged 2.6 g/d per 100-g fish, wet weight), and 1.5 g/d per 100-g fish. The daily phosphorus intakes at the two levels per 100-g fish were 3.1 and 1.8 mg. The average phosphorus concentration was 2.4 mg/g in muscle and 15.4 mg/g in the whole fish. Worm food was spiked with P-32 at increasing daily increments to balance radioactive decay. The radioactive worms were fed daily to the bluegill during the P-32 accumulation period of 51 days. For the next 28 days of depuration, nonradioactive worms were fed. Sets of three bluegill were collected at approximately weekly intervals, sectioned and analyzed for P-32 and phosphorus. All data were reported as specific activity in tissue relative to specific activity in feed, with P-32 count rates corrected for its 14.3-day half life. Phosphorus turnover constants were obtained by three approaches: (1) from the relative specific activity measured near steady state; (2) by fitting an equation for a 1-compartment model to the accumulation and depuration data; and (3) by fitting an equation for a simplified 2-compartment model to the depuration data. The biological turnover constant calculated with all three approaches was 0.004 d−1 for phosphorus in muscle of bluegill fed ad lib.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00008804
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  • 21
    Electronic Resource
    Electronic Resource
    Lake Kinneret phytoplankton: Response to N and P enrichments in experiments and in nature (1988)
    Springer
    Hydrobiologia 166 (1988), S. 65-75 
    Details
    ISSN: 1573-5117
    Keywords: Phytoplankton ; Subtropical Lake ; Nitrogen ; Phosphorus ; Nutrient enrichment ; Chlorophyta ; Flagellates ; Cyanophyta ; Bacillariophyta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A series of water samples from Lake Kinneret was supplemented with 100 µM N (as NH4 or as NO3 and/or 10 µM orthophosphate-P. The yield of phytoplankton both as chlorophyll and in cell numbers of major species was determined after a two-week incubation. During these experiments, some of the algae present initially never multiplied (e.g. Peridinium and Peridiniopsis spp. Cryptomonas spp., Rhodomonas spp. and Crysochromulina parva); others e.g. Anomoeoneis exilis, Synedra sp., Chlamydomonas sp., Elakatothrix gelatinosa), undetected in the original sample, grew out during the incubation. Chlorophyte species (the majority of commonly observed forms in the lake) responded most readily to added nutrients. The results of these enrichment experiments were related to the long-term record of phytoplankton populations observed in the lake and suggest that through summer and fall, when ambient levels of both P and N are minimal, P was generally, but not always, the most limiting nutrient for algal growth. In the spring, after the decline of the Peridinium bloom, P appeared to be limiting the growth of Chlorophyta. Although most algal species grew equally well on NH4 or NO3, some species appeared to respond preferentially either to the former (Coelastrum, Chodatella) or to the latter (Chroococcus, Anomoeoneis) source of N.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017484
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  • 22
    Electronic Resource
    Electronic Resource
    Phosphorus in soil, water and sediment: an overview (1988)
    Springer
    Hydrobiologia 170 (1988), S. 19-34 
    Details
    ISSN: 1573-5117
    Keywords: Phosphorus ; mineral ; soil ; sediment ; sorption ; transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The geochemistry, availability and abundance of different forms of phosphorus in soil, water and sediments are reviewed. The present knowledge of phosphorus pathways in ecosystems and their regulation is discussed. In a drainage basin, anthropogenic phosphorus is brought into the system mainly as fertilizers and detergents. Sewer systems and outwash processes transfer the phosphorus from the terrestrial environment to the aquatic part of the ecosystem where an accumulation occurs in the sediments of the watercourse. A great part of the phosphates in soil is sorbed to soil particles or incorporated into soil organic matter. The release and export of phosphorus from uncultivated soil is a function of the geology and soil composition, but also of the air temperature, precipitation and the hydrological condition, pH etc. The solubility of phosphates is controlled by either sorption-desorption or precipitation-dissolution reactions depending on the environment in the soil or sediments. In soil and sediments with large amounts of iron and aluminium hydrous oxides, sorption-desorption reactions are largely responsible for determining the level of orthophosphate in the solution at equilibrium. Algal availability of phosphorus associated with soil-derived materials present in aquatic systems deserves more research. In addition, processes responsible for transport of phosphorus from cropland to aquatic systems and chemical and microbial transformations of phosphorus in lakes and streams deserve more attention.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00024896
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  • 23
    Electronic Resource
    Electronic Resource
    Reduction and Hydrogenation with the System Hydrocarbon/Carbon [New Synthetic Methods (70)]Dedicated to Professor Helmut Dörfel on the occasion of his 60th birthday (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 679-682 
    Details
    ISSN: 0570-0833
    Keywords: Reduction ; Hydrogenation ; Hydrocarbons ; Carbon ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the synthesis of organic compounds, reduction is an indispensible reaction type which is also widely used on an industrial scale. In industrial processes hydrogen is usually used as reducing agent, since strong reducing agents like alkali metals and hydrides can only be used to a limited extent for safety and economic reasons. Very economical reducing agents that are convenient to handle and have high potential application are hydrocarbons in presence of carbon. Hydrocarbon/carbon systems can be readily used instead of molecular hydrogen and expensive metal catalysts for the hydrogenation of compounds containing, for example, CC-, CO-, or NO-double bonds. Furthermore, these systems can be used for carrying out reductions which hitherto required strong reducing agents such as zinc, tin, alkali metals and hydrides. Especially suitable as economic sources of hydrogen are refinery products such as vacuum gas oil, fuel oil S or vacuum residue oil. Hydrocarbons are dehydrogenated to unsaturated systems and finally to carbon.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198806791
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  • 24
    Electronic Resource
    Electronic Resource
    Cyclobutanones and Cyclobutenones in Nature and in Synthesis [New Synthetic Methods(71)]Dedicated to Professor Vladimir Prelog (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 797-827 
    Details
    ISSN: 0570-0833
    Keywords: Cyclobutanes ; Cyclobutenes ; Synthetic methods ; Natural products ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical reactivity of cyclobutanones and cyclobutenones is considerably different from that of cyclic ketones with larger rings; this is due to their ring strain of ca. 25 kcal/mol. Detailed knowledge regarding the influence of this ring strain on regio-, chemo- and stereoselective transformations of four-membered ring ketones is of particular importance. While several reactions, such as the Baeyer-Villiger reaction, the Beckmann and Favorskii rearrangements and cine-substitution often proceed in a manner specific to four-membered rings, other reactions such as the facile ring-opening by nucleophiles, the rearrangement to tropolones, the thermal [2+2]-cycloreversion, the isomerization to vinylketenes and the photochemical formation of oxacarbenes are rather specific to cyclobutanones and cyclobutenones. The remarkable selectivity and the excellent yields of such transformations, which are favored or caused by ring strain as the inherent driving force, offer the synthetic chemist fascinating possibilities for the development of new strategies for the synthesis of natural products and biologically active compounds.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198807971
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  • 25
    Electronic Resource
    Electronic Resource
    Transition Metals in the Synthesis and Functionalization of Indoles [New Synthesis Methods (72)] (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 1113-1126 
    Details
    ISSN: 0570-0833
    Keywords: Indoles ; Synthetic methods ; Transition metals ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of transition-metal complexes as reagents for the synthesis of complex organic compounds has been under development for at least several decades, and many extraordinary organic transformations of profound potential have been realized. However, adoption of this chemistry by the practicing synthetic organic chemist has been inordinately slow, and only now are transition-metal reagents beginning to achieve their rightful place in the arsenal of organic synthesis. Several factors contributed to the initial reluctance of synthetic organic chemists to use organometallic reagents. Lacking education and experience in the ways of elements having d electrons, synthetic chemists viewed organometallic processes as something mysterious and unpredictable, and not to be discussed in polite society. Organometallic chemists did not help matters by advertising their latest advances as useful synthetic methodology, but restricting their studies to very simple organic systems lacking any serious functionality (e.g., the “methyl, ethyl, butyl, futile” syndrome). Happily, things have changed. Organometallic chemists have turned their attention to more complex systems, and more recently trained organic chemists have benefited from exposure to the application of transition metals. This combination has set the stage for major advances in the use of transition metals in the synthesis of complex organic compounds. This review deals with one aspect of this area, the use of transition metals in the synthesis of indoles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198811133
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  • 26
    Electronic Resource
    Electronic Resource
    Zeolites: Catalysts for Organic SynthesesDedicated to Professor Helmut Dörfel on the occasion of his 60th birthday (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 226-246 
    Details
    ISSN: 0570-0833
    Keywords: Zeolites ; Catalysis ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Zeolites have proved to be valuable technical catalysts in petrochemistry and in oil processing. The characteristic properties of zeolites, such as acidity, shape-selectivity and thermal stability also enable them to be used for highly selective synthesis in the fields of chemical intermediates and fine chemicals. This interesting area of application has grown continuously in recent years. The present article summarizes the various standard types of reaction involved in organic syntheses which can be catalyzed by zeolites; these include, inter alia, electrophilic and nucleophilic substitution reactions, isomerization of double bonds and carbon skeletons, as well as addition, elimination and hydrogenation reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198802261
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  • 27
    Electronic Resource
    Electronic Resource
    Ketenimine Complexes from Carbene Complexes and Isocyanides: Versatile Building Blocks for Carbocycles and N-Heterocycles [New Synthetic Methods (74)]Dedicated to Professor Ernst Otto Fischer on the occasion of his 70th birthday (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 1456-1467 
    Details
    ISSN: 0570-0833
    Keywords: Ketenimines ; Carbene ligands ; Isocyanides ; Carbocycles ; Heterocycles ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ketenimine complexes are readily available in great variety by reaction of isocyanides with carbene complexes. They have proven to be useful building blocks in new synthetic approaches to carbocyclic and N-heterocyclic four-, five-, and six-membered rings. The reactions involve new metal-induced bond formation patterns of the ketenimine ligands, which can be influenced across a wide range by varying the following five parameters: the metal, the ligands, and the three substituents on the N=C=C unit.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198814561
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  • 28
    Electronic Resource
    Electronic Resource
    Phosphaalkynes - Syntheses, Reactions, Coordination Behavior [New Synthetic Methods (73)]Phosphorus Compounds with Unusual Coordination, Part 30. Part 29: [119]. (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 1484-1508 
    Details
    ISSN: 0570-0833
    Keywords: Phosphaalkynes ; Synthetic methods ; Phosphorus-carbon compounds ; Multiple bonds ; Heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organophosphorus compounds have been applied in two ways in chemical synthesis. They can either be used as a reagent in a step of the synthesis (for example, in the Wittig reaction) or they can be incorporated directly into the target molecule. This second application, in particular, has expanded greatly in the last few years with the preparation of low-coordination phosphorus compounds. These include the phosphaalkynes, which are of great interest to organic and inorganic chemists. Phosphaalkynes have been employed in the synthesis of heterocyclic compounds, phosphaarenes and their valence isomers, and polycyclic compounds. Further applications have been the use of phosphaalkynes as new ligand systems in complex chemistry and their cyclooligomerization with organometallic reagents. While the chemical properties of phosphaalkynes have little in common with those of nitriles, they are in many ways very similar to those of the isoelectronic acetylenes.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198814841
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  • 29
    Electronic Resource
    Electronic Resource
    Microbial and Enzymatic Processes for the Production of Biologically and Chemically Useful Compounds [New Synthetic Methods (69)] (1988)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 27 (1988), S. 622-642 
    Details
    ISSN: 0570-0833
    Keywords: Synthetic methods ; Enzyme catalysis ; Fermentation ; Biotechnology ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In recent years, the most significant development in the field of synthetic organic chemistry has been the application of biological systems to chemical reactions. Reactions catalyzed by enzymes and enzyme systems display far greater specificities than more conventional organic reactions. Biological and/or enzymatic syntheses and transformations, that is, “microbial transformations,” have great potential. Some of these reactions have already been shown to have useful applications in the fields of synthetic organic chemistry and biotechnology. This article reviews the current status of the rapidly developing field of microbial transformation, the methodology, available technological procedures, and fields of application being described especially in relation to conventional organic synthesis methods.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198806221
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  • 30
    Electronic Resource
    Electronic Resource
    Microbial activity and nutrient dynamics in earthworm casts (Lumbricidae) (1987)
    Springer
    Biology and fertility of soils 5 (1987), S. 230-234 
    Details
    ISSN: 1432-0789
    Keywords: Earthworm casts ; Microbial respiration ; Microbial biomass ; Nitrogen ; Phosphorus ; Aporrectodea caliginosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Microbial respiration, microbial biomass and nutrient requirements of the microflora (C, N, P) were studied in the food substrate (soil taken from the upper 3 cm of the mineral soil of a beech wood on limestone), the burrow walls and the casts of the earthworm Aporrectodea caliginosa (Savigny). The passage of the soil through the gut caused an increase in soil microbial respiration of about 90% over a 4-week period. Microbial biomass was increased only in freshly deposited casts and decreased in aging faeces to a level about 10% lower than in soil. Microbial respiration of the burrow walls was only increased over a shorter period (about 2 weeks). The microflora of the soil and the burrow walls was limited by P, whereas in earthworm casts, microbial growth was limited by the amount of available C. In aging faeces the P requirement of the microflora increased and approached that of the soil. Immobilization of phosphate in earthworm casts is probably caused by mainly abiotic processes. C mineralization by soil microflora fertilized with glucose and P was limited by N, except in freshly deposited casts. Ammonium, not nitrate, was responsible for this process. N dynamics in earthworm casts are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00256906
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  • 31
    Electronic Resource
    Electronic Resource
    Reducing fertilizer requirements for hybrid squash (Cucurbita maxima L.) with localized applications of phosphorus and potassium and use of partially acidulated phosphate rock (1987)
    Springer
    Nutrient cycling in agroecosystems 13 (1987), S. 169-180 
    Details
    ISSN: 1573-0867
    Keywords: Phosphorus ; potassium ; fertilizer placement ; triple-superphosphate ; partially acidulated phosphate rock ; hybrid squash ; Cucurbita maxima L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two experiments examined options for reducing the inputs of P and K fertilizers for hybrid squash (Cucurbita maxima L.) at Pukekohe, New Zealand. The first experiment examined the effects of elevating the NaHCO3-soluble P from 32 to 130 mg kg−1 and the exchangeable K from 140 to 350 mg kg−1 within strips from 0 to 0.75 m around rows of hybrid squash planted 1.5 m apart. From both P and K, crop yield increased as the width of the fertilized strip was increased up to 0.25 m, while wider fertilized strips had no further effect. These results followed similar effects on plant dry matter and tissue P or K concentration during early growth, and are explained in terms of the P and K accumulation by the crop, the decline during growth of the sensitivity of the crop to soil P and K fertility associated with declining rates of P and K uptake per unit length of root. Implications for fertilizer management for hybrid squash are also discussed. The second experiment compared the effects of partially acidulated phosphate rock and triple-superphosphate on soil P fertility, growth and yield of hybrid squash. Partially acidulated phosphate rock had smaller effects than those of triple-superphosphate on NaHCO3-soluble P levels in the soil, plant dry weight and tissue P concentration soon after emergence, and subsequently crop yield. On average, partially acidulated phosphate rock increased crop yield by about 70% of that following the application of the same quantity of P as triple-superphosphate. This lower effectiveness of partially acidulated phosphate rock for hybrid squash is explained in terms of its lower solubility and hence smaller effect on NaHCO3-soluble P in the soil during early growth, when the crop is most sensitive to soil P fertility.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01064830
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  • 32
    Electronic Resource
    Electronic Resource
    The increase in skin 7-dehydrocholesterol induced by an hypocholesterolemic agent is associated with elevated 25-hydroxyvitamin D3 plasma level (1987)
    Springer
    Pflügers Archiv 410 (1987), S. 165-168 
    Details
    ISSN: 1432-2013
    Keywords: Cholesterol ; 1,25 Vitamin D3 ; Calcium ; Phosphorus ; Calcemia ; Hypocholesterolemia ; 7-Dehydrocholesterol reductase ; Epidermis ; Rat UV radiation ; Skin vitamin D3 synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Vitamin D3 is generated in skin by UV irradiation of 7-dehydrocholesterol (7-DEHC). Whether the 7-DEHC amount in skin affects vitamin D3 formation, and thereby the plasma level of 25-hydroxyvitamin D3 (25[OH]D3) is not known. In the present work we report on the influence on vitamin D and Ca metabolism of a new hypocholesterolemic agent, HCG-917 (0-2-[hydroxy-3-]N′-(2-chlorophenyl)-N-piperazinyl-1-[propyl]-4-chloro-benz-aldoxim-hydrochloride) which inhibits 7-DEHC reductase and thereby increases skin 7-DEHC. Rats were treated with HCG 917 (0.3 and 5.0 mg/kg, orally) for 13 days. HCG 917 caused a dose-dependent decrease in cholesterol and concomitant accumulation of 7-DEHC in plasma and skin. In skin, 7-DEHC was: control: 1.05±0.20; HCG 917, 0.3 mg/kg: 1.41±0.22; HCG 917, 5.0 mg/kg: 2.35±0.35 mg/g. At a dose of 0.3 mg/kg, HCG 917 had no significant influence on the plasma level of neither 25(OH)D3 nor 1,25(OH)2D3. However, at a dose of 5.0 mg/kg, HCG 917 induced a significant increase in plasma 25(OH)D3 (control: 36.2±2.2; HCG 917 5.0 mg/kg: 57.6±6.5 nmol/l) and a slight but not significant rise in 1,25(OH)2D3. Calcium balance studies indicated that HCG 917 did not influence intestinal Ca absorption nor urinary Ca excretion. At a dose of 5.0 mg/kg HCG 917 slightly induced a decrease in total plasma Ca. In conclusion, HCG 917 treatment can induce a significant rise in skin 7-DEHC with an increase in plasma 25(OH)D3. These results suggest that variation in the skin level of 7-DEHC can directly influence the cutaneous production of vitamin D3 and thereby the vitamin D status of the organism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581910
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  • 33
    Electronic Resource
    Electronic Resource
    The effect of nitrogen and phosphorus addition on the growth, reproduction, and nutrient dynamics of two ericaceous shrubs (1987)
    Springer
    Oecologia 71 (1987), S. 541-547 
    Details
    ISSN: 1432-1939
    Keywords: Ericaceae ; Nitrogen ; Phosphorus ; Deciduous ; Evergreen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Aboveground growth, reproduction, and foliar nitrogen and phosphorus contents of two ericaceous shrub species were compared over two seasons in (a) an undisturbed shrub bog (pocosin), and (b) a factorial fertilization design in which three levels each of nitrogen and phosphorus were added in all possible combinations. One species, Zenobia pulverulenta, is deciduous whereas the other species, Lyonia lucida, is evergreen. In the nutrient-poor undisturbed pocosin the two species exhibited similar foliar nitrogen and phosphorus concentrations and aboveground growth rates. Neither species flowered. In response to nutrient-addition Zenobia increased growth rates more than Lyonia. Foliar phosphorus concentrations of both species increased in response to enhanced phosphorus availability. in the first season neither species flowered in any treatment. In the second season Zenobia flowered only in the fertilized plots, with the most flowering in the high phosphorus treatments. I conclude that, by virtue of high growth rates and efficient use of nutrients and despite differences in leaf phenology and morphology, both Lyonia and Zenobia are successful in a competitive community under conditions of extremely low phosphorus availability. However, unlike Lyonia, Zenobia can take advantage of temporarily increased nutrient availability, which occurs following fire in the pocosin, to increase growth and reproduction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00379294
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  • 34
    Electronic Resource
    Electronic Resource
    Resorption of foliar nutrients in a regenerating southern Appalachian forest (1987)
    Springer
    Oecologia 73 (1987), S. 268-271 
    Details
    ISSN: 1432-1939
    Keywords: Foliar nutrients ; Resorption ; Succession ; Nitrogen ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Leaves were sampled in a successional, southern Appalachian forest to estimate autumn foliar nutrient dynamics. Resorption of N and P in a successional forest equaled, or exceeded, resorption estimates for a more mature control forest. Foliar nutrient leaching was not sufficient to account for changes in autumn leaf N, P, Ca and Mg concentrations. The resorption process conserves nutrients by reducing nutrient losses from leaching and litter-fall, thereby closing the nutrient cycle in successional forests. We hypothesize that rapid recovery of primary productivity early in forest regeneration is the result of maximum nutrient resorption of limiting nutrients. Implications of these results for successional nutrient cycling theory are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377517
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    Electronic Resource
    Bioassays of nutrient limitation in a tropical rain forest soil (1987)
    Springer
    Oecologia 74 (1987), S. 370-376 
    Details
    ISSN: 1432-1939
    Keywords: Costa Rica ; Miconia ; Piper ; Nitrogen ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Six speices of shrubs and one large herb with contrasting life history patterns were used as bioassays of nutrient availability in a Costa Rican lowland rain forest soil. Growth responses of the herb (Phytolacca rivinoides, Phytolaccaceae) confirmed soil measurements indicating high availability of N and potentially limiting levels of P, K, Mg and Ca. Growth responses of the shrub species (Miconia spp., Melastomataceae and Piper spp., Piperaceae) to a complete nutrient fertilizer were generally less than that of Phytolacca. Lack of a strong shrub response to +P fertilization is probably due to mycorrhizal associations and slower growth rates of woody species. In general, increased growth did not occur at the expense of phenolic production in the leaves. The results emphasize that assessment of specific nutrient limitations to plant growth vary depending on species selected for the bioassay, even among species from the same community.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378932
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  • 36
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    Evaluation of mineral metabolism and bone turnover in osteoporotic females treated with phosphorus and salmon calcitonin (1987)
    Springer
    Clinical rheumatology 6 (1987), S. 504-509 
    Details
    ISSN: 1434-9949
    Keywords: Senile Osteoporosis ; Phosphorus ; Salmonn Calcitonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-five patients with radiological and clinical evidence of osteoporosis were studied. Nineteen patients received oral phosphorus at a dose of 1,000 mg/die for 10 days followed by salmon calcitonin (100 U MRC/die) for 20 days. Six patients received only oral calcium at a dose of 1,000 mg/die). In the first group, a significant increase in serum osteocalcin and parathyroid hormone, after administration of phosphorus and persisting after treatment with salmon calcitonin, was found. No variation in the controls was observed. In a later study, a significant increase in serum 1,25 dihydroxyvitamin D (1,25(OH)2D3), after receiving phosphorus and persisting after salmon calcitonin, was demonstrated. In accordance with the authors' results, phosphorus could be considered a useful activator of bone formation and this stimulus by parathyroid hormone was mediated. Finally, the positive effects of phosphorus on circulating 1,25(OH)2D3 must be considered for a good treatment protocol of osteoporosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02330586
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    Phosphorus nutrition of jarrah (Eucalyptus marginata) seedlings (1987)
    Springer
    Plant and soil 97 (1987), S. 369-379 
    Details
    ISSN: 1573-5036
    Keywords: Bark ; Calcium phosphate ; Eucalyptus marginata ; Fertilizer ; Leaf ; Lignotuber ; Phosphorus ; Shoot growth ; Wood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Effects of calcium phosphate supply on plant dry matter and phosphorus concentrations of parts of jarrah (Eucalyptus marginata) seedlings grown in a lateritic topsoil from the jarrah forest were examined in two glasshouse trials. Phosphorus deficiency depressed root and shoot dry weights and severely deficient leaves were smal and purple with prominent red major veins. Phosphorus deficiency severely reduced stem phosphorus levels (0.5% to 0.02%, experiment 1). Phosphorus concentrations were higher in bark than wood and the amount of phosphorus in the bark was sensitive to stem age and phosphate supply. Phosphorus adequate plants had bark phosphorus concentrations in the range 0.2–0.9% compared to 〈0.1% in deficient plants (experiment 2). Jarrah leaves accumulated dry matter up to 80 days after expansion and some leaves exported phosphorus during this period. Bark analysis may therefore be preferable to leaf analysis for detecting phosphorus deficiency in this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02383227
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  • 38
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    The effect of pretransplant inoculation with VA mycorrhizal fungi on the subsequent growth of leeks in the field (1987)
    Springer
    Plant and soil 97 (1987), S. 279-283 
    Details
    ISSN: 1573-5036
    Keywords: Copper ; Dazomet ; Field experiment ; Leek ; Phosphorus ; Pretransplant inoculation ; VA mycorrhiza ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Leek plants were preinoculated with a mixed inoculum ofGlomus caledonium, Glomus fasciculatum andGlomus sp., and transplanted to Dazomet disinfected and untreated field plots of moderate P deficiency. Successive harvests were made until 99 days after transplanting. Preinoculated leeks attained marketable weights 25 days earlier than uninoculated leeks from untreated soil and their final dry matter yields were 5.7 and 1.5 times as high as those of uninoculated leeks from disinfected and untreated soil, respectively. Phosphorus concentration in preinoculated leeks remained highest for at least 22 and 75 days after transplanting in untreated and disinfected soil, respectively. Preinoculation had a similar, although smaller, influence on Cu and Zn concentrations. Infection levels produced by introduced and indigenous VA endophytes in leeks reached plateaus of 90% and 40%, respectively, 47 days after transplanting. It is concluded that VAM is essential to leeks grown in moderately P deficient soils, and the potential for inoculating seedlings in commercial leek production is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374951
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    The effects of ferulic acid on the mineral nutrition of grain sorghum (1987)
    Springer
    Plant and soil 98 (1987), S. 99-109 
    Details
    ISSN: 1573-5036
    Keywords: Allelopathy ; Ferulic acid ; Magnesium ; Mineral content ; Phosphorus ; PotassiumSorghum bicolor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two week old sorghum seedlings (Sorghum bicolor L. Moench) were treated with ferulic acid added to the nutrient solution. Effects on tissue concentration of P, K, Mg, Ca, Fe, and Zn were evaluated after 3 and 6 days. Treatemnts of 0.25 mM ferulic acid approximated the growth inhibition threshold, and after 6 days 0.5 mM treated plants weighed less than controls. Both treatments reduced the P content of the roots and shoots at the 3- and 6-day harvests in three replicate experiments. Roots of treated plants at both harvests had a lower concentration of K and Mg. These reductions in P, K, and Mg were most extensive from the 0.5 mM ferulic acid regime. In some cases at both harvests, shoot K was lower and Mg was higher than control tissue. Ferulic acid effects at the 3-day harvest included an elevation of Ca and depression of Fe in shoots. Changes in nutrient content preceded measurable differences in plant weight. These data indicate that one mechanism of growth inhibition by this allelochemical may be an alteration of nutrient balance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381731
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  • 40
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    Nutrient variation in forest soil samples due to time of sampling and method of storage (1987)
    Springer
    Plant and soil 98 (1987), S. 363-375 
    Details
    ISSN: 1573-5036
    Keywords: Ammonium ; Forest soil samples ; Nitrate ; pH ; Phosphorus ; Potassium ; Sample storage ; Seasonal variation ; Soil analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study was carried out in order to assess the importance of storage procedures and time of sampling for the results of routine chemical analyses of forest soils. Humus and mineral soil samples were collected at five-week intervals during two growing seasons from a sample plot in a coniferous forest in northern Sweden. The samples were either air-dried (+35°C) or frozen (−20°C). After a few months they were analysed for ‘easily available’ and ‘relatively available’ phosphorus (P-AL and P-HCl) and potassium (K-AL and K-HCl), ammonium, nitrate and pH. In some cases there was a significant difference between the two sample treatments. In humus, the concentrations of P-AL and NH4-N were 51% and 76% higher in samples which had been frozen than in those which had been air-dried while the concentrations of NO3-N were 75% higher. in air-dried than in frozen samples. In mineral soil samples, 21–64% higher concentrations of K-AL were found in frozen samples compared to air-dried and 80–427% higher concentrations of NO3-N in air-dried than in frozen samples. No distinct seasonal variations were found for any of the parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02378358
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  • 41
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    Totally Synthetic Routes to the Higher Monosaccharides (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 15-23 
    Details
    ISSN: 0570-0833
    Keywords: Monosaccharides ; Synthetic methods ; Carbohydrates ; Heptoses ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The evolution of a strategy to synthesize the title compounds is described. Three principal developments allowed realization of this goal: (1) the attainment of high margins of diastereofacial selectivity and regioselectivity in the construction of pyranoid systems via the Lewis acid-catalyzed cyclocondensation reaction of activated dienes and aldehydes; (2) the exploitation of stereoselective reactions for functionalization of the pyranoid matrix; and (3) the discovery of stereoselective reactions for extending the chiral biases of pyranoid systems to newly emerging stereogenic centers on side chains. The coordination of these components in the synthesis of target systems of high biological interest is described.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198700151
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    Directed Homogeneous Hydrogenation [New Synthetic Methods (65)] (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 190-203 
    Details
    ISSN: 0570-0833
    Keywords: Homogeneous hydrogenation ; Hydrogenation ; Synthetic methods ; Catalysis ; Stereoselectivity ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stereochemical control is a major concern in the application of homogeneous catalysis to organic chemistry. In this context, the directed hydrogenation of olefins employing cationic rhodium or iridium catalysts has considerable potential, for very high selectivity can be attained under mild reaction conditions. The only requirement is a polar functional group in proximity to the double-bond which remains bound to the metal during the catalytic cycle and thereby controls the Stereochemical course of hydrogen delivery through the constraints of chelation. The substituent is most frequently a hydroxy group OH but can also be an ester, amide or carbamate group; other groups remain to be scrutinized. In cyclic compounds, directed hydrogenation can lead to face-selectivity, and the polar substituent may be in the β-, γ-, or δ-position to the double-bond. Acyclic stereoselection ensues with β- or γ-substituents in appropriate compounds, and the configuration of reduced product is predictable on the basis of simple rules. The application of optically active rhodium complexes leads to useful kinetic resolution procedures.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198701901
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    Synthesis of Glycopeptides, Partial Structures of Biological Recognition Components [New Synthetic Methods (67)]An expanded version of a lecture delivered on October 24, 1985, at the Max-Bergmann Conference in Bozen.Dedicated to Professor Leopold Horner on the occasion of his 75th birthday (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 294-308 
    Details
    ISSN: 0570-0833
    Keywords: Glycopeptides ; Molecular recognition ; Molecular recognition ; Synthetic methods ; Carbohydrates ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Glycopeptides are partial structures of the connecting regions of glycoproteins and, like these, always contain glycosidic bonds between the carbohydrate and peptide parts. Glycoproteins are not only widely distributed but are also decisive factors in post-translational biological selectivity, especially in biological recognition. Targeted syntheses of glycopeptides require stereoselective formation of the glycosidic bonds between the carbohydrate and the peptide parts and protective group methods that enable selective deblocking of only one functional group in these polyfunctional molecules. These heavy demands have been met by the well-established use of benzylic protective groups, which can be removed by hydrogenolysis, combined with the use of base-labile 2-phosphonioethoxycarbonyl (Peoc) or 9-fluorenylmethoxycarbonyl (Fmoc) protective groups or of bromoethyl esters, which can be removed under neutral conditions. The acidolysis of tert-butyloxycarbonyl (Boc) groups and of tert-butyl esters has also been successfully used, although, under acidic conditions, anomerization or rupture of the glycosidic bonds may occur, especially when nucleophiles are present. The stable, two-stage 2-(pyridyl)ethoxycarbonyl (Pyoc) protective groups allow a more reliable synthesis of complex glycopeptides since they can be removed, after modifications, under mild conditions. Particularly suitable for the synthesis of sensitive glycopeptides are the stable allyl protective groups. They can be removed from the complex glycopeptides in a highly selective and effective manner by means of noble-metal catalysts under practically neutral conditions. These methods have been employed to synthesize glycopeptides corresponding to partial structures of interesting glycoproteins. Deprotected glyopeptides representing tumor-associated antigen structures can be coupled to bovine serum albumin, which serves as a biological carrier molecule, without the necessity of using an artificial coupling component (spacer).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198702941
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    Polyphosphorus Compounds - New Results and PerspectivesContributions to the Chemistry of Phosphorus, Part 178. - Part 177: [106].Dedicated to Professor Heinz Harnisch on the occasion of his 60th birthday (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 419-441 
    Details
    ISSN: 0570-0833
    Keywords: Polyphosphorus compounds ; Phosphorus ; Polyphosphanes ; Phosphanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In contrast to the numerous known and often technically important mono- and diphosphorus compounds with phosphorus in its maximum oxidation state, polyphosphorus compounds led only a shadowy existence up to about twenty years ago. One of the reasons for this was the properties of such compounds, which made their handling and structural characterization difficult. This problem was solved by the development of modern preparative techniques and, especially, by the further methodological development of nuclear magnetic resonance spectroscopy. Thus, a fascinating new branch of phosphorus chemistry has been opened up in recent years. The first comprehensive review on this subject was published five years ago. Since then, research on this “element-near” chemistry of phosphorus has produced further impressive advances with the result that a surprisingly large variety of compounds with skeletons consisting of chains or rings of phosphorus atoms is known today. However, the recent observation of the spontaneous formation of the “aromatic” pentaphosphacyclopentadienide ion, P5-, during the synthesis of phosphorus-richer polyphosphides from phosphorus-poorer compounds in solution and the discovery of the inversion of phosphorus in tetra- and pentacyclic organophosphanes demonstrate that this field is still capable of producing surprises.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198704191
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    Stereoselective Aldol Reactions with α-Unsubstituted Chiral EnolatesDedicated to Professor George Büchi on the occasion of his 65th birthday (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 24-37 
    Details
    ISSN: 0570-0833
    Keywords: Stereoselective aldol reactions ; Aldol reaction ; Chiral enolates ; Enolates ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aldol reaction is among the most important methods of forming carbon-carbon bonds. The addition of an enolate to an aldehyde leads to the formation of at least one chiral center. In the case of α-substituted enolates it has to a large extent been possible to control the product stereochemistry, while the aldol reaction of α-unsubstituted chiral enolates was for many years a “problem child” for synthetic chemists because of its insufficient stereoselectivity. Progress in this area has only been made in the last few years using either new chiral auxiliaries or alternatives to the aldol reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198700241
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    New Reductive Transformations of Unsaturated Cyclic Hydrocarbons [New Synthetic Methods (66)] (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 204-217 
    Details
    ISSN: 0570-0833
    Keywords: Synthetic methods ; Reduction ; Carbanions ; Cycloannelation ; Cycloalkenes ; Polycycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The successive reduction of fully conjugated cyclic hydrocarbons leads to singly and multiply charged ions with unusual bonding. The charge distribution in these ions can be determined spectroscopically, and the information so obtained is then used in kinetically controlled trapping reactions for the regioselective introduction of electrophilic groups. When non-benzenoid substrates are used, syntheses become possible which can either not be carried out or can only be carried out with great difficulty in other ways. Examples of new preparative applications are cycloannelation and bridging reactions as well as polymerization reactions. The ion pair structure of the intermediate and the type of electrophile used are of paramount importance in controlling the mechanism of these reductive transformations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198702041
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    Stereoselective Syntheses of Building Blocks with Three Consecutive Stereogenic Centers: Important Precursors of Polyketide Natural Products [New Synthetic Methods (68)] (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 26 (1987), S. 489-503 
    Details
    ISSN: 0570-0833
    Keywords: Natural products ; Synthetic methods ; Polyketides ; Stereoselectivity ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sequences of directly adjacent stereogenic centers were first discovered for the monosaccharides, which therefore constituted the first focus of interest in Stereoselective synthesis. The structures of many polyketide-derived natural products that have been elucidated in recent years often exhibit longer sequences of stereogenic centers in which hydroxy-substituted secondary carbon atoms alternate with tertiary carbon atoms. This finding inspired the development of methods allowing the specific construction of first two and then - more importantly-three neighboring stereogenic centers. The diverse methodologies that have thereby emerged reveal common principles and stress the variety of approaches possible in stereoselective synthesis.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198704893
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    Nutrient transport between ryegrass plants differeing in nutrient status (1986)
    Springer
    Oecologia 70 (1986), S. 128-131 
    Details
    ISSN: 1432-1939
    Keywords: Lolium ; Nitrogen ; Nutrient transfer ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It is known that nitrogen and phosphorus can be transferred from one living plant to another, but it is not known whether the amounts transferred are large enough to influence the growth of the species in the field. Two Lolium perenne plants were grown per pot of unfertilized soil. During 25 weeks one plant (the ‘donor’) in each pot was fed nutrients through leaves; donors in control pots received only water. The ‘receiver’ plants which shared a pot with the nutrient-fed donors increased significantly, compared with the controls, in leaf number and concentration of phosphorus, though not in concentration of nitrogen, potassium, calcium or magnesium. The rate of phosphorus transfer agreed well with previous results using 32P. The results are compared with rates of phosphorus uptake in the field. It is concluded that nutrient transfer could have an influence on the balance between coexisting species in the field, but probably the influence will be small.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377121
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    Distribution of carbon, nitrogen and phosphorus in a moss community-soil system developed on a cold desert in Antarctica (1986)
    Springer
    Ecological research 1 (1986), S. 59-69 
    Details
    ISSN: 1440-1703
    Keywords: Antarctica ; Carbon ; Moss community ; Nitrogen ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distributions of carbon, nitrogen and phosphorus in a moss community-soil system developed on a naked region in Rundvågskollane (69050'S, 39009'E), East Antarctica, were investigated in order to analyze the flow of matter in an Antarctic terrestrial ecosystem. 1) The moss community was formed from many moss blocks of different sizes and was composed ofBryum pseudotriquetrum (Hedw.) Gaertn., Meyer et Scherb.,Ceratodon purpureus (Hedw.) Brid. andGrimmia lawiana J. H. Willis. The surface of the community was covered with cyanobacteria. 2) It was estimated that nitrogen fixed by cyanobacteria flowed from these organisms to the moss and that little nitrogen was transported within the moss body. 3) A large amount of phosphorus existed in the soil. The moss community had a high phosphorus content although the amount itself was relatively little due to the small phytomass. 4) It seems that absorption of phosphorus from soil is difficult for moss, because of the paucity of water necessary for the movement of phosphorus and the suppressed growth of moss due to the arid conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02361205
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  • 50
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    The influence of drainage and soil phosphorus on the vegetation of Douala-Edea Forest Reserve, Cameroun (1986)
    Springer
    Plant ecology 65 (1986), S. 149-162 
    Details
    ISSN: 1573-5052
    Keywords: Africa ; Cameroun ; Douala-Edea ; Drainage ; Gradient ; Phosphorus ; Rain-forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract All living trees (≥30 cm gbh) were enumerated in 104 80×80 m plots arranged along four transects in the Douala-Edea Forest Reserve Cameroun, a system of low-lying ancient coastal sand dunes interspersed by numerous streams and swamps. The extent of permanent and seasonal swamps was recorded for each plot. Two hundred thirty taxa were recognized of which 63% were identified to species. Mean tree density was 376 ha−1, basal area 31.0 m2 ha−1 and number of species per plot 39. The Olacaceae were the most abundant family in terms of basal area, but the Euphorbiaceae the most frequently represented. The most abundant species wasCoula edulis (Olacaceae). Twenty-two plots had most of their area permanently or seasonally swamped. Percentage sand, silt and clay ranged between 32–100, 0–64, 0–21% respectively. The ranges for other variables recorded were: pH (2.7–5.4), organic carbon (1.5–12.4%), available phosphorus (7–90 ppm) and potassium (28–188 ppm), and nitrogen (ammonium 4–40 ppm, nitrate 1–12 ppm). Classification of the plots on the basis of six soil variables provided three large distinct groups: swamp plots and non-swamp plots, the latter divided into plots of low and high available soil phosphorus. Swamp plots were distinguished by high abundances ofProtomegabaria stapfiana andLibrevillea klainei, though correspondence ordination of plots in these groups showedP. stapfiana associated with more clayey soils andLibrevillea klainei (andGluema ivorensis) on the very sandy soils. Direct gradient analysis highlighted several species associated with these lower phosphorus soils. Available soil phosphorus is not as low at Douala-Edea as in parts of Korup, and the association of these Douala-Edea soils with the Caesalpinioideae is correspondingly weaker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00044815
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    The influence of topography and soil phosphorus on the vegetation of Korup Forest Reserve, Cameroun (1986)
    Springer
    Plant ecology 65 (1986), S. 131-148 
    Details
    ISSN: 1573-5052
    Keywords: Africa ; Cameroun ; Gradient ; Korup ; Phosphorus ; Rain-forest ; Topography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract All living trees (≥30 cm gbh) were enumerated in 135 80×80 m plots, each subdivided into four 40×40 m subplots, and arranged along four 5 km transect lines in the Korup Forest Reserve, Cameroun. For each plot altitude, slope and the extent of permanent and seasonal swamps were recorded. Four hundred and eleven taxa were recognized of which 66% were identified to species. Mean tree density was 471 ha−1, basal area 27.6 m2 ha−1 and number of species per plot 75. The subfamily Caesalpinioideae (Leguminosae) was the most abundant family/subfamily in terms of basal area, but the Scytopetalaceae the most frequently represented, mainly on account ofOubanguia alata. Ten plots had at least three quarters of their area permanently swamped, and three, to a similar extent, were seasonally swamped. The ranges in sand, silt and clay content were 60–91, 0–24 and 4–20% respectively. The pH value, organic carbon content and nitrate-nitrogen concentration ranged between 4.0–5.8, 1.3–5.7% and 0–35 ppm respectively. The largest soil variations were in available phosphorus, range 2–29 ppm, and potassium, 38–375 ppm. Correspondence analysis ordination of all plots showed a major indirect floristic gradient correlated with increasing altitude, slope and soil phosphorus and potassium. Removal of the topographic effect by separate re-ordinations of four groups of plots at low, middle (2) and high altitude/slopes highlighted a strong correlation of the main floristic gradients of the middle altitude/slope groups with the concentration of available soil phosphorus. Direct gradient analysis using all plots with respect to available soil phosphorus concentration confirmed the indirect analyses. Individual species response to phosphorus were also shown by direct comparisons in the vegetation on plots of high and low available soil phosphorus concentration. Low available phosphorus soils (≤5 ppm) are strongly associated with species of the subfamily Caesalpinioideae, especially of the tribes Amherstieae and Detarieae. It is suggested that this result is probably due to the ability of these particular legume tribes to form associations with ectotrophic mycorrhizae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00044814
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    Long-term effects of cutting tap roots ofPinus caribaea growing on infertile savanna soils (1986)
    Springer
    Plant and soil 93 (1986), S. 137-140 
    Details
    ISSN: 1573-5036
    Keywords: Calcium ; Magnesium ; Phosphorus ; Pinus caribaea ; Potassium ; Savanna ; Tap root
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The content of elements in needles ofPinus caribaea trees growing upon infertile savanna soils was analysed at 3 and 5 years after the tap roots of a subset of trees had been severed. No significant differences were found between the content of elements in treated and control trees, nor were significant differences found in increments of diameter of the trees over 5 years. It is concluded that this organ plays no significant nutritional role in the trees on these soils, and that tree growth can be achieved exclusively from atmospheric nutrient accessions and exchangeable nutrient reserves in the topsoil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02377154
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    The effects of soil temperature on the response of lettuce seedlings to starter fertilizer (1986)
    Springer
    Plant and soil 93 (1986), S. 183-193 
    Details
    ISSN: 1573-5036
    Keywords: Ammonium phosphate ; Lactuca sativa L. ; Phosphorus ; Placement ; Potassium phosphate ; Root-shoot ratio ; Soil temperature ; Starter fertilizer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A pot experiment is described which investigated the effects of placing starter fertilizer, 1 cm beneath the seeds, on growth and nutrient uptake in lettuce seedlings at two soil temperatures (10°C and 20°C). At both temperatures the presence of starter fertilizer increased nutrient concentrations within the plants. At 20°C there was no growth response to the starter treatments. However, at 10°C there was a large response to the application of starter fertilizer. The best treatment was a combination of NH4H2PO4 and KH2PO4 which increased plant dry weight by 64% at 19 days from sowing. Nutrient deficiency caused a significant increase in the root length/shoot weight ratio of the control plants at 10°C. The responses to the starter were shown to be determined by the balance between the demand for nutrients from the shoots and the supplying power of the roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374220
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  • 54
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    Electronic Resource
    Fate of applied nutrients in a long-term superphosphate trial inPinus radiata (1986)
    Springer
    Plant and soil 93 (1986), S. 373-382 
    Details
    ISSN: 1573-5036
    Keywords: Calcium ; Fertilizer ; Magnesium ; Nitrogen ; Nutrient content ; Phosphorus ; Pinus radiata ; Potassium ; Superphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nutrient contents of aPinus radiata stand, that is, aboveground tree, understorey, forest floor and soil to 200 mm depth, were estimated in a replicated fertilizer trial, treated 30 years previously. The fertilizer treatments were 0, 25, 50, 75 and 100 kg P/ha as broadcast superphosphate. Highly significant growth responses had been obtained to the applied P. Estimation of the P content of the stand showed that 129%, 89%, 72% and 67% of the applied P was found in the 25, 50, 75 and 100 kg P/ha treatments respectively. The larger losses of P at the higher application rates would explain the lack of increased response with the highest application rate, however, it also shows that significant quantities of P are still present after a period of 30 years, giving a basis for growth responses in the subsequent rotations. Elevated quantities of N, Ca, Mg and K were found in the treatments compared with the control and these could not be explained on the basis of atmospheric inputs. For the cations, uptake from deeper in the soil profile could explain most of the effect but not for the higher amounts of N which, in the case of the highest superphosphate treatment, amounted to an accumulation of 27 kg N/ha/yr. These nutrient changes together with increased soil organic matter contents are considered to have provided a long term increase to the site productivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374288
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  • 55
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    Development of two endomycorrhizal symbioses on soybean and comparison with phosphorus fertilization (1986)
    Springer
    Plant and soil 95 (1986), S. 361-377 
    Details
    ISSN: 1573-5036
    Keywords: glomus fasciculatum ; Glomus mosseae ; Glycine max ; Phosphorus ; Specific P Uptake Rate (SPUR) ; Vesicular-arbuscular mycorrhiza (VAM)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Soybean (Glycine max L. Merr. cv. Amsoy 71) plants were grown in a greenhouse in a soil very low in plant-available P, and plants were harvested 5 times over a 21-week growth period. Soybeans were inoculated with one of two species of VAM fungi or received daily one of three nutrient solutions of different P concentrations (0.0, 0.2, or 1.0mMP). Until week 9, the dry weights, leaf areas and developmental stage of soybeans inoculated withG. fasciculatum orG. mosseae were similar to the 1.0 or 0.2mMP-treated plants, respectively. Phosphorus concentrations were significantly lower in VAM plants at weeks 6 and 9 as compared to non-VAM soybeans given 1.0mMP, suggesting P input in VAM plants was immediately used for new growth. Total P input for VAM plants was linear over 21 weeks, and the average rate of P uptake for these plants was 0.19mg P d−1. Estimated specific P uptake rates (SPUR) for the mycorrhizae (VAM roots) were twice that of the control (0.0mMP) roots. The calculated SPURs forG. fasciculatum andG. mosseae hyphae were 95 and 120μg P g−1 VAM d−1 respectively, a 4 to 5 fold increase over non-inoculated roots, indicating more attention must be paid to P assimilation by VAM fungi in P-fixing substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374617
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  • 56
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    Effects of temperature and prior flooding on intensity and sorption of phosphorus in soil (1986)
    Springer
    Plant and soil 95 (1986), S. 173-181 
    Details
    ISSN: 1573-5036
    Keywords: Apparent heat of sorption ; Bonding energy ; Flooded-drain ; Phosphorus ; Phosphate ; Sorption ; Temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of temperature and prior flooding of soil on P sorption were examined in 2 soils having a rice-based cropping system and showing an induced P deficiency problem in flooded rice-uplant crop rotations. The P sorption capacity of soil increased with increasing temperature as well as with prior flooding, the effects of the latter were, howerver, dominant. The bonding energy of sorption, calculated from the Langmuir isotherm, also increased with both temperature and prior flooding of soils, indicate that the effects of chemical changes associated with alternative anoxic and oxidized soil conditions are more significant in the P reversion process. The apparent heat of sorption reaction, calculated with the Freundlich isotherm and Van't Hoff's equation also increased due to prior flooding of soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02375069
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  • 57
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    Sorption and bioavailability of phosphorus during the drainage period of flooded-drained soils (1986)
    Springer
    Plant and soil 92 (1986), S. 265-278 
    Details
    ISSN: 1573-5036
    Keywords: Bioavailability ; Bonding energy ; Flooded-drained ; Phosphorus ; Phosphorus sorption ; P uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Changes in P sorption and bioavailability were studied with 4 soils previously flooded and drained as occurs in rice-based cropping systems. Phosphorus sorption was measured at 15 and 119 days after drainage and the bioavailability of added and native soil-P was determined at 9, 16, 30, 45, 70 and 135 days in both flooded-drained and unflooded soils. The P sorptivity and bonding energy of sorption increased under flooded-drained soil conditions. At 119 days after drainage the P sorptivity and bonding energy of sorption decreased as compared to 15 days after drainage. The P sorptivity of the flooded-drained soils, however, did not reach the same levels as existed in the soils prior to flooding. The bioavailability of P during the drainage period remained low and did not measurably change up to 70 days after drainage. At 135 days after drainage the bioavailability of P increased significantly, but did not reach the level found in the corresponding unflooded soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02372640
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  • 58
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    Phosphorus deficiency induced by nitrogen input in Douglas fir in the Netherlands (1986)
    Springer
    Plant and soil 95 (1986), S. 191-200 
    Details
    ISSN: 1573-5036
    Keywords: Atmospheric input ; Douglas fir Fertilization ; Foliar analysis ; Forest nutrition ; N/P ratio ; Nitrogen ; Nutrient status ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A re-examination of earlier NPK fertilization experiments in Douglas fir stands on sandy soils shows the effects of high nitrogen input by air pollution during the last 10–15 years on plant nutrition at these sites. In 1960, experimental plots showed a positive growth reaction to nitrogen, phosphorus, and potassium fertilization. All suffered from severe phosphorus deficiency in 1984, low phosphorus in the needles was invariably accompanied by a high nitrogen content, with all N/P ratios between 20 and 30. The same conclusion emerges from an independent investigation of nutrient status of a selection of Douglas fir stands. Hence, if stand productivity and a balanced nutrient status of the trees is to be maintained, the increase in atmospheric input of nitrogen calls for supplementary fertilization. Given the current N/P ratios in the needles, a positive growth response to phosphorus fertilization is to be expected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02375071
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  • 59
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    Growth response ofTheobroma cacao L. seeldings to inoculation with vesicular-arbuscular mycorrhizal fungi (1986)
    Springer
    Plant and soil 96 (1986), S. 279-285 
    Details
    ISSN: 1573-5036
    Keywords: Mycorrhiza ; Phosphorus ; Plant growth ; Theobroma cacao
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of vesicular-arbuscular mycorrhiza (VAM) on the growth and phosphorus uptake of cocoa seedlings (Theobroma cacao L.) grown for 100 days in polythene bags, were studied at five levels of phosphorus fertilization in both steamed and unsterile Bungor Series soil (a fine clayey, kaolinitic isohyperthermic Typic Paleudult). The cocoa seedlings responded well to phosphorus fertilization and mycorrhizal treatments. Plants inoculated with VAM fungi (Gigaspora spp.) gave the most vigorous growth and higher phosphorus in the leaf tissues in unsterile soil compared to plants grown in steamed soil. However, the mycorrhizal effect was significantly more pronounced (P〈0.01) in plants grown in steamed than in unsterile soil. High levels of phosphorus application depressed mycorrhizal development. Phosphorus fertilizer applied at the rates of 250 and 500 ug g−1 soil gave maximum root colonization and spore counts in both soil types used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374771
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  • 60
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    Nitrate and ammonium absorption by plants growing at a sufficient or insufficient level of phosphorus in nutrient solutions (1986)
    Springer
    Plant and soil 91 (1986), S. 313-318 
    Details
    ISSN: 1573-5036
    Keywords: Ammonium uptake ; Barley ; Brassica napus L. ; Buckwheat ; Cation-anion balance ; Fagopyrum esculentum Moench ; Hordeum vulgare L. ; Nitrate uptake ; Phosphorus ; Rape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Absorption of nitrate and ammonium was studied in water culture experiments with 4 to 6 weeks old plants of barley (Hordeum vulgare L.), buckwheat (Fagopyrum esculentum L. Moench) and rape (Brassica napus L.). The plants were grown in a complete nutrient solution with nitrate (5.7±0.2 mM) or nitrate (5.6±0.2 mM) + ammonium (0.04±0.02 mM). The pH of the nutrient solution was kept at 5.0 using a pH-stat. It was found that phosphorus deficiency reduced the rate of nitrate uptake by 58±3% when nitrate was the sole N source and by 83±1% when both nitrate and ammonium were present. The reduction occurred even before growth was significantly impeded by P deficiency. The inhibition of the uptake of ammonium was less,i.e. ammonium constituted 10±1% of the total N uptake in the P sufficient plants and 30±5% in the P deficient plants. The reduction of nitrate absorption greatly decreased the difference between the uptake of anions and cations. It is suggested that P deficiency reduced the assimilation of NO 3 − into the proteins, which might cause a negative feedback on NO 3 − influx and/or stimulate NO 3 − efflux.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02198114
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  • 61
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    New Methods for the Synthesis of Glycosides and Oligosaccharides - Are There Alternatives to the Koenigs-Knorr Method? [New Synthetic Methods (56)]Dedicated to Professor Rudolf Gompper on the occasion of his 60th birthday (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 212-235 
    Details
    ISSN: 0570-0833
    Keywords: Glycosides ; Oligosaccharides ; Koenigs-Knorr method ; Synthetic methods ; Carbohydrates ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Glycoproteins, glycolipids, and glycophospholipids (glycoconjugates) are components of membranes. The oligosaccharide residue is responsible for intercellular recognition and interaction; it acts as a receptor for proteins, hormones, and viruses and governs immune reactions. These significant activities have stimulated interest in oligosaccharides and glycoconjugates. With their help it should be possible to clarify the molecular basis of these phenomena and to derive new principles of physiological activity. Major advances in the synthesis of oligosaccharides have been made by the use of the Koenigs-Knorr method, in which glycosyl halides in the presence of heavy-metal salts are employed to transfer the glycosyl group to nucleophiles. The disadvantages of this procedure have led to an intensive search for new methods. Such methods will be discussed in this article. Emphasis is placed on glycoside and saccharide formation by 1-O-alkylation, on the trichloroacetimidate method, and on activation through the formation of glycosylsulfonium salts and glycosyl fluorides.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198602121
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  • 62
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    Organic Synthesis at High Temperatures. Gas-Phase Flow Thermolysis [New Synthetic Methods (57)]Part of the Habilitationsschrift, M. Karpf, Universität Zürich 1984. (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 414-430 
    Details
    ISSN: 0570-0833
    Keywords: Gas-phase flow thermolysis ; Thermolysis ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preference for carrying out synthetic organic reactions at the lowest possible temperature is due to the expectation that the selectivity often increases with decreasing temperature, as is confirmed by many examples and also theoretically justified. Selectivity, however, is not the only problem at high temperatures; further factors include the frequently limited thermal stability of the functional groups and structural elements not directly involved in the transformation. In spite of these limitations, the advantages of high temperatures and the greatly improved knowledge of the mechanisms of dynamic gas-phase processes accumulated in recent years can be exploited in directed organic synthesis. In this review the synthetic potential of gas-phase flow thermolysis will be described from the viewpoint of the synthetic chemist with the aid of typical examples of application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198604141
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  • 63
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    The Palladium-Catalyzed Cross-Coupling Reactions of Organotin Reagents with Organic Electrophiles [New Synthetic Methods (58)] (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 508-524 
    Details
    ISSN: 0570-0833
    Keywords: Cross-coupling ; Organotin compounds ; Electrophilicity ; Palladium ; Catalysis ; C-C coupling ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. Because this mild, versatile reaction is tolerant of a wide variety of functional groups on either coupling partner, is stereospecific and regioselective, and gives high yields of product, it is ideal for use in the synthesis of elaborate organic molecules. When the coupling reaction is carried out in the presence of carbon monoxide, instead of a direct coupling, carbon monoxide insertion takes place, stitching the two coupling partners together and generating a ketone.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198605081
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  • 64
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    Hydroxide Ion Initiated Reactions Under Phase Transfer Catalysis Conditions: Mechanism and Implications. New Synthetic Methods (62) (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 960-970 
    Details
    ISSN: 0570-0833
    Keywords: Phase-transfer catalysis ; Catalysis ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The development of Phase Transfer Catalysis (PTC) represents a major step forward in the employment of many organic reactions and renders them very convenient and useful processes. These reactions involve the application of nucleophiles in general, anions and bases in particular, in reactions carried out in a water-organic solvent system. They can be performed both in the laboratory and on an industrial scale. The ease of application of PTC processes is the main reason for their increasing utilization in industry. An outstanding achievement of this technique is the employment of aqueous bases in reactions which traditionally would otherwise require a strong base in a nonaqueous medium. The classical procedures that require severe anhydrous conditions, expensive solvents and dangerous bases such as metal hydrides and organometallic reagents are now replaced by aqueous solutions of, e.g., sodium or potassium hydroxides (PTC/OH processes). In contrast to the extensive synthetic applications of PTC/OH systems, the detailed mechanisms of these processes have been the subject of a great deal of controversy and various mechanisms have been suggested. However, it would seem that our knowledge concerning the mechanistic aspects of such reactions has now reached the stage where it can be used to advantage in synthesis planning. A better understanding of the various factors which influence the reaction would undoubtedly help to optimize PTC/OH processes such as to enable higher yields in shorter reaction times at lower temperatures. The importance of, inter alia, the catalyst will be pointed out and it is highly recommended that such catalysts be always available in the laboratory, for the range of organic reactions that they can efficiently, conveniently and safely catalyze is vast indeed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198609601
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  • 65
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    [3+2] Cycloaddition Approaches to Five-Membered Rings via Trimethylenemethane and Its Equivalents [New Synthetic Methods (55)] (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 1-20 
    Details
    ISSN: 0570-0833
    Keywords: Cycloaddition ; Trimethylenemethane ; Synthetic methods ; Cyclopentanes ; Heterocycles ; Natural products ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The power of cycloadditions for ring formation derives from the potential for chemo-, regio-, diastereo-, and enantioselectivity. Trimethylenemethane (TMM) and its equivalents offer the possibility of extending such benefits to the synthesis of five-membered rings. Three types of conjunctive reagents appear to be promising candidates: (1) selected 4-alky-lidene-4,5-dihydro-3H-pyrazoles, (2) 2-[(trimethylsilyl)methyl]allyl esters and halides, and (3) alkylidenecyclopropanes. Thermal reactions, especially intramolecular ones, effect the cycloaddition of the pyrazoles to olefins-especially electron-poor olefins. The latter two precursors require a catalyst, notably a palladium complex, to unlock the synthetic potential. With the 2-[(trimethylsilyl)methyl]allyl esters, a general chemo-, regio-, and diastereoselective cycloaddition with typical Diels-Alder dienophiles forms methylenecyclopentanes in both inter- and intramolecular fashion. A tin analogue allows extension of this cycloaddition to aldehydes, and, in a related sequence, to ketones and imines to form 3-methylenete-trahydrofurans and 3-methylenepyrrolidines with excellent diastereoselectivity. The 2-[(tri-methylsilyl)methyl]allyl esters also serve to effect net methylenecyclopentane annulation to cyclic enols. Such adducts can further undergo three-carbon intercalation or combined ring contraction-spiroannulation simply by the use of either a nucleophilic or electrophilic trigger. Alkylidenecyclopropanes undergo cycloadditions to both electron-rich and electron-poor olefins when stimulated by metal catalysts, especially palladium. A complementary regiochemistry to the approach based upon silicon conjunctive reagents is observed. The availability of these cycloadditions provides new strategies for the synthesis of natural products.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198600013
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  • 66
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    Indirect Electroorganic Syntheses - A Modern Chapter of Organic Electrochemistry [New Synthetic Methods (59)] (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 683-701 
    Details
    ISSN: 0570-0833
    Keywords: Electroorganic synthesis ; Electrochemistry ; Synthetic methods ; Redox chemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrochemical formation and regeneration of redox agents for organic syntheses (indirect electrolysis) widens the potential of electrochemistry, as higher or totally different selectivities can often be obtained while at the same time the energy input can be lowered significantly. Higher current densities can also be obtained by preventing otherwise often encountered electrode inhibition. New types of redox catalysts can be formed in-situ and can be regenerated after reaction with the substrates. This principle is of increasing importance also for the application of already known redox agents with regard to environmental protection, since large amounts of a product can be generated in a closed circuit using only relatively small amounts of the redox reagent. Consequently the operation of such a process can be greatly simplified, and the release of ecologically objectionable spent reagents into the environment can be prevented. The broad spectrum of redox catalysts currently in use includes, inter alia, metal salts in very low or high oxidation states, halogens in various oxidation states, and, in particular, a wide variety of transition-metal complexes. A great deal of progress has recently been made in the application of organic electron transfer agents, since compounds have been found that are sufficiently stable in both the reduced as well as the oxidized state.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198606831
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  • 67
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    Total Synthesis of Anthracyclinone [New Synthetic Methods (60)]Dedicated to Professor Albert Mondon on the occasion of his 70th birthday (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 790-807 
    Details
    ISSN: 0570-0833
    Keywords: Anthracyclinones ; Synthetic methods ; Antibiotics ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The remarkable antitumor properties of anthracycline antibiotics have motivated synthetic chemists, and a large number of groups have been active recently in this field. Initially, there was very little hope for this class of substances due to their extreme toxicity. However, the dividing line between toxicity and desired pharmacological effect has broadened to such an extent, partly through microbiological methods (new strains, mutants) and partly through semisynthetic modifications, that today anthracyclines take number one place (over 20% of the market) in the chemotherapy of (human) cancer. The demands made on modern cytostatica are extremely high, as may be seen from the fact that of the more than 600000 drugs tested in animals, only about 40 are in clinical use. In the meantime, some anthracyclines obtained by total synthesis are also in clinical testing. In this review it will hopefully be demonstrated that all those concerned in the chemotherapeutic use of these substances have also contributed to the general progress made in the solution of regio- and stereo-chemical problems of linearly annelated ring systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198607901
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  • 68
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    Selective Synthesis by Use of Lewis Acids in the Presence of Organocopper and Related Reagents. New Synthetic Methods (61) (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 947-959 
    Details
    ISSN: 0570-0833
    Keywords: Lewis acids ; Synthetic methods ; Selectivity ; Organocopper compounds ; Addition ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organometallic compounds with pronounced nucleophilicity such as organocopper and organolithium compounds, and powerful electrophiles, such as BF3 and AlCl3, are generally thought to be incompatible under normal, homogeneous reaction conditions. As a matter of course, it is anticipated that the two species cannot coexist and undergo transmetalation reactions. To our surprise, however, RCu and BF3 are compatible at low temperature. RCu·BF3 and related organocopper-Lewis acid reagents exhibit new and unique reactivities and selectivities: in conjugate additions, e.g., not only activation but also high regio-, stereo-, and chemo-selectivity as well as very high asymmetric induction is observed; allylic derivatives are alkylated regioselectively, and reaction towards carbonyl groups, imines, epoxides, aziridines, ethers, acetals, orthoformates, and pyridinium salts is in each case found to be selective. RLi·BF3 and related organolithium-Lewis acid reagents also exhibit noteworthy selectivities and reactivities. These complex reagents are utilized in the key steps of the total synthesis of many important natural products, such as certain terpenes, steroids, and alkaloids.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198609473
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  • 69
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    The aluminum-induced increase in blood-brain barrier permeability to delta-sleep-inducing peptide occurs throughout the brain and is independent of phosphorus and acetylcholinesterase levels (1985)
    Springer
    Psychopharmacology 86 (1985), S. 84-89 
    Details
    ISSN: 1432-2072
    Keywords: Blood-brain barrier ; Aluminum ; Dementia ; Peptides ; Phosphorus ; Acetylcholinesterase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of aluminum on levels of inorganic phosphorus and acetylcholinesterase in blood and brain and on permeability of the blood-brain barrier (BBB) in different regions of the brain to the neuropeptide deltasleep-inducing peptide (DSIP) was studied in adult rats. Aluminum (100 mg/kg) significantly increased the permeability of the BBB to intracarotid 125I-N-Tyr-DSIP so that levels of radioactivity in whole brain were 45% higher than in control animals. The pattern of regional distribution of radioactivity in the brain was, however, unaffected, demonstrating that the affect of aluminum occurs throughout the BBB. Aluminum also significantly decreased inorganic phosphorus levels in the serum by 19%, but this effect did not correlate with BBB permeability to DSIP. Aluminum did not decrease brain levels of phosphorus despite the drop in blood levels of phosphorus nor affect brain or blood levels of acetylcholinesterase. Experiments with radioactive 32P reinforced the finding that blood but not brain levels of phosphorus are reliably affected by aluminum. The lack of correlation between changes in BBB permeability and decreased levels of inorganic phosphorus in the blood suggests that the effect of aluminum may not be mediated by its effects on phosphorus metabolism. Also, the change in BBB permeability after administration of aluminum does not appear to depend on changes in brain cholinergic activity but does occur throughout the brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431689
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    Nutrient fluxes in a eutrophic coastal Louisiana freshwater lake (1985)
    Springer
    Environmental management 9 (1985), S. 243-251 
    Details
    ISSN: 1432-1009
    Keywords: Water quality ; Nitrogen ; Phosphorus ; Sedimentation ; 137Cs dating ; Freshwater lake ; Nutrient sinks ; Eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nitrogen and phosphorus cycling in a eutrophic Louisiana freshwater lake system (Lac des Allemands) was studied. Nutrients from runoff entering the lake, as well as sediment-interstitial and lake water nitrogen and phosphorus fractions, were measured seasonally. Sedimentation rates in the lake were determined using137Cs dating. Phosphorus levels in the lake were found to be largely dependent on concentrations in the incoming bayou water from upland drainage. Lake water concentrations appear to respond to fluctuations in incoming waters. Laboratory equilibrium studies showed bottom sediments in the lake are a major sink for the incoming dissolved orthophosphate phosphorus. Total nitrogen concentrations in the lake water generally exceeded incoming runoff concentrations, suggesting fixation by the large blue-green algae population in the lake as being the major source of nitrogen to the system. Sedimentation ranged from 0.44 cm/year to 0.81 cm/year, depending on the proximity to the inlet bayous. Even though the lake is eutrophic the sediment served as a buffer by removing large amounts of carbon, nitrogen, and phosphorus through sedimentation processes. Carbon, nitrogen, and phosphorus were accumulating in the sediment at rates of 60, 7.1, and 1.1 g/m2/year, respectively. The water quality of the lake is likely to continue to decline unless measures are taken to reduce municipal, industrial, and agricultural inputs of phosphorus into the lake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867080
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  • 71
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    Effects of synthetic and microbially produced chelates on the diffusion of iron and phosphorus to a simulated root in soil (1985)
    Springer
    Biology and fertility of soils 1 (1985), S. 45-52 
    Details
    ISSN: 1432-0789
    Keywords: Iron ; Phosphorus ; Siderophore ; Hydroxamate ; Chelates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Hydroxamate siderophores (HS) are microbially produced, ferric-specific chelates, known to occur in soil, and to be capable of providing iron to higher plants. This study examined the potential for HS to influence the diffusion of both iron and phosphorus to plant roots in soil. The HS desferrioxamine-B (DFOB) and desferriferrichrome (ferrichrome) were compared with the synthetic chelates ethylenediamine [di(o-hydroxyphenylacetic)acid] (EDDHA) and ethylenediamine-tetraacetic acid (EDTA), and citrate, oxalate, and distilled water in their ability to increase diffusion of iron using a simulated root technique. Chelate solutions were pumped through porous fiber bundles imbedded in soil previously labeled with55Fe. In a sandy loam of pH 7.5,55Fe diffusion caused by 10−4 M DFOB was twice that of water, but similar to that caused by 10−4 M EDDHA. However, 10−3 M EDDHA resulted in greater diffusion than 10-3 M DFOB. The diffusions resulting from equimolar quantities of citrate, oxalate, and EDTA were similar to that with distilled water. In a clay soil of pH 5.2 previously labeled with55Fe and32 P, the response in55Fe diffusion to chelate treatments was: 10−4 M EDDHA 〉 10−4 M ferrichrome 〉 10−3 M DFOB 〉 10−4 M DFOB 〉 water. Both ferrichrome and EDDHA caused2 P diffusion to increase substantially over that of distilled water. These results suggest that hydroxamate siderophores present in the rhizosphere could effectively increase the level of soluble iron for root uptake and possibly increase phosphorus uptake by solubilization of phosphorus from iron phosphates at acid pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00710970
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  • 72
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    Comparative effects of four mycorrhizal fungi on loblolly pine seedlings growing in a greenhouse in a Piedmont soil (1985)
    Springer
    Plant and soil 83 (1985), S. 215-221 
    Details
    ISSN: 1573-5036
    Keywords: Cecil soil type ; Phosphorus ; Pinus taeda ; Scleroderma aurantium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A greenhouse study was conducted to evaluate the effect of ectomycorrhizae on loblolly pine (Pinus taeda L.) growing in a Piedmont soil. Pine seedlings were inoculated with one of four species of fungi (Scleroderma aurantium, Pisolithus tinctorius, Thelophora terrestris, andRhizopogon roseolus). The seedlings were grown in pots containing a Cecil sandy clay loam amended to create a gradient of extractable P ranging from 5.9 to 52.5 μg/g. After ten months, all colonized seedlings were significantly larger than control seedlings. However, of the four fungi,Scleroderma aurantium mediated a far superior shoot growth response to increasing levels of soil P; the seedlings were significantly larger than those colonized by any other fungus and also had the largest root systems and greatest degree of mycorrhizal colonization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02184293
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  • 73
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    Influence of nitrogen and phosphorus fertilizers on ammonia-assimilating enzymes of Azolla (1985)
    Springer
    Plant and soil 88 (1985), S. 271-273 
    Details
    ISSN: 1573-5036
    Keywords: Ammonia assimilating enzymes ; Anabaena azollae ; Azolla ; Nitrogen ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A field experiment was conducted and studied the effect of nitrogen and phosphorus on ammonia assimilating enzymes of Azolla. Nitrogen and phosphorus at 30 and 60 kg/ha respectively were tested andAzolla pinnata was inoculated at 200 g/m2. The Azolla samples were drawn on 24th hr, 7th day and 14th day and the ammonia assimilating enzymes glutamine synthetase (GS), glutamate synthase (GOGAT) and glutamine dehydrogenase (GDH) were estimated. Nitrogen and phosphorus have markedly suppressed the GDH activity but fertilizer nitrogen has no significant influence in inhibiting the enzyme activity of GOGAT and GS. In general phosphorus application also has stimulated the GS activity significantly during the first sampling period of 24th hour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02182453
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  • 74
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    Electronic Resource
    Fertilization management of crops irrigated with saline water (1985)
    Springer
    Plant and soil 89 (1985), S. 285-299 
    Details
    ISSN: 1573-5036
    Keywords: Calcium ; Chloride ; Ion antagonism ; Magnesium ; Nitrate ; Nitrogen ; Nutrition disorders ; Phosphorus ; Salinity-fertility relationship ; Sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Available data concerning nutrition and fertilization effects on crops irrigated with saline water are presented and discussed. Published data on the salinity-fertility relationship are, at least to some extent, contradictory; both positive and negative effects as well as no effect of fertilization on salinity tolerance have been recorded. However, a great deal of the experimental work supports the view that standard fertilization recommendations for non-saline conditions are also suitable for saline conditions. In addition, available data indicate that the apparent salt tolerance of agricultural crops varies with soil fertility level. Consequently, crops showing exceptionally high apparent salt tolerance at a low fertility level become more sensitive when adequately fertilized, although the absolute yield may be greatly increased. On the other hand, some data seem to show a real increase in salinity tolerance under improved fertility conditions. Important information concerning the responses of plants to salinity under various fertility levels was obtained by tissue analysis. It should be kept in mind that this information may be influenced also by the plant species and by environmental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02182248
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  • 75
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    Influence of washing on elemental analysis of leaves of fieldgrown crop plants (1985)
    Springer
    Plant and soil 88 (1985), S. 93-100 
    Details
    ISSN: 1573-5036
    Keywords: Aluminum ; Calcium ; Copper ; Glycine max ; Iron ; Magnesium ; Manganese ; Nitrogen ; Phosphorus ; Potassium ; Sorghum bicolor ; Triticum aestivum ; Zea Mays ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Information is limited on soil contamination of leaves from field-grown row crops, especially with respect to aluminum (Al) analyses. The objective of this study was to determine the influence of washing leaf samples with either deionized water or detergent solution on elemental analyses for several agronomic crop plants. The crop plants sampled were corn (Zea mays L.), soybean (Glycine max L. Merr.), grain sorghum (Sorghum bicolor L. Moench), and wheat (Triticum aestivum L.). The crops were grown on a range of soil types, soil pH values, and tillage practices. Samples of upper leaves and lower leaves were collected separately. The samples were either not washed, washed with deionized water, or washed with detergent solution. After drying, grinding, and digesting, the samples were analyzed for Al, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). For all crop plants and conditions studied, there was no effect on measured N, P, K, Ca, Mg, Mn, Zn, or Cu concentrations, but measured Al and Fe concentrations were influenced by washing. In general, washing had a greater effect on Al analyses than on Fe analyses. Soybean samples were most affected by washing, while wheat samples seemed to be least affected. The results reflected greater contamination of lower leaves than upper leaves. Decontamination procedures appear necessary prior to Al and Fe analyses of field-grown crop plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02140668
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  • 76
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    Distribution of N, P, K, Ca, Mg, S, Zn, Fe, Mn and Cu in groundnut (1985)
    Springer
    Plant and soil 84 (1985), S. 269-273 
    Details
    ISSN: 1573-5036
    Keywords: Calcium ; Copper ; Groundnut ; Iron ; Kernel ; Kharif ; Leaflet ; Magnesium ; Manganese ; Nitrogen ; Petiole ; Phosphorus ; Potassium ; Root ; Shell ; Stem ; Sulphur ; Summer ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02143189
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  • 77
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    Nutrient proportions in foliage of semi-mature loblolly pine (1985)
    Springer
    Plant and soil 86 (1985), S. 27-34 
    Details
    ISSN: 1573-5036
    Keywords: Loblolly pine ; Nitrogen ; Nutrient ratios ; Phosphorus ; Pinus taeda
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nitrogen and phosphorus limitations to growth are common in many loblolly pine (Pinus taeda) stands. Interactions of these nutrients may complicate interpretation of foliar nutrient analysis for predicting response to forest fertilization. Proportions of foliar nutrient concentrations (and the changes in these proportions following fertilization) were examined in 36 semi-mature loblolly pine plantations in the southeastern United States. Mean proportions of nutrient concentrations (N∶P∶K∶Ca∶Mg) for non-fertilized stands were 100∶9.3∶36.5∶17.2∶9.2. Potassium and phosphorus were higher. Nitrogen fertilization generally decreased the P∶N ratio and enhanced growth, indicating a nitrogen deficiency in most stands under study. Additions of nitrogen and phosphorus together yielded a significant increase in the P∶N ratio. Effects of fertilization effects on other nutrient concentration ratios were also examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02185022
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  • 78
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    Phosphorus accumulation by lignotubers of jarrah (Eucalyptus marginata Donn ex Sm.) seedlings grown in a range of soils (1985)
    Springer
    Plant and soil 86 (1985), S. 225-232 
    Details
    ISSN: 1573-5036
    Keywords: Eucalyptus marginata ; Lignotuber ; Nitrogen ; Phosphorus ; Seedlings ; Virgin soils X-ray probe microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Jarrah seedlings were grown in six virgin Western Australian soils for up to 27 months. Lignotubers were produced in all soils and formed 10–16% of plant dry weight. The phosphorus concentration in the lignotuber (250–800 μg g−1) was nearly twice that in the stem and roots. The lignotuber contained 10–30% of total plant phosphorus and like the leaves was a sink for phosphorus. In one lateritic soil the phosphorus concentrations of lignotuber and stem barks were similar. However, in the same plants the concentration of phosphorus in the lignotuber wood was five times the phosphorus concentration in stem wood. Hence both lignotuber bark and sap wood in young jarrah seedlings are storage sites for phosphorus. X-ray probe analysis showed that wood phosphorus was associated with the ray parenchyma. Unlike phosphorus, nitrogen did not accumulate in the lignotuber and the concentrations of nitrogen were similar for roots, lignotubers and stems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02182897
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  • 79
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    Effect of zinc fertilization on the mineral nutrition of rices differing in tolerance to zinc deficiency (1985)
    Springer
    Plant and soil 87 (1985), S. 319-327 
    Details
    ISSN: 1573-5036
    Keywords: Copper ; Iron ; Magnesium ; Manganese ; Mineral nutrition ; Nutrient translocation ; Phosphorus ; Rice ; Varietal tolerance ; Zinc ; Zinc fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of four Zn levels on the electrochemical and chemical properties of the soil solution, and on the growth and mineral nutrition of two rice varieties (IR26 and IR34) differing in tolerance to Zn deficiency were studied in the greenhouse using Zn-deficient soils from two locations. A similar experiment was conducted in culture solution to check how Zn addition affects translocation of other nutrients. In both soil and culture solution, plant Zn concentrations alone was not enough to account for varietal tolerance to Zn deficiency. Comparison of nutrient to Zn and shoot to root ratios of nutrients was more useful in determining the possible mechanism of varietal tolerance. IR 34 appeared to tolerate the disorder due to its lower Zn requirement, more efficient Zn translocation and ability to maintain lower Fe/Zn, Cu/Zn, Mg/Zn and P/Zn ratios in the shoot than the more susceptible variety, IR26. This was shown to be due to decreased translocation of Fe, Mg and P to shoots and decreased absorption of Cu by the root in IR34 in culture solution studies. Adding Zn further reduces translocation or absorption of these nutrients and depending on the nutrient supply of the soil, could cause deficiencies or mineral imbalances, especially of Fe, Cu, and P. These observed varietal differences regarding Zn requirement and the interaction of Zn with absorption and translocation of plant nutrients necessitates revision of recommendations for Zn fertilization. There is an inevitable need for Zn application in severely Zn-deficient soils regardless of rice variety. But on marginally Zn-deficient soils especially those low in Fe, Cu, or P, Zn fertilization is not advisable when resistant rice varieties are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02181899
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  • 80
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    Chiral Compounds Synthesized by Biocatalytic Reductions [New Synthetic Methods (51)] (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 24 (1985), S. 539-553 
    Details
    ISSN: 0570-0833
    Keywords: Chirality ; Reduction ; Synthetic methods ; Enzymes ; Biotechnology ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It has been known for many decades that chiral compounds can be obtained by stereospecific biocatalytic reduction. Further significant methodological developments in this field have, however, only been made during the past ten years; they include the application of previously unused microorganisms and electron donors, the discovery of additional substrates for the known reductases, the development of methods for regenerating reduced pyridine nucleotides, and the discovery of new reductases which were sought for specific preparative purposes. Many chiral compounds can now be synthesized by microbial hydrogenation using H2 and hydrogenase-containing microorganisms as well as by electromicrobial or electroenzymatic reduction. In the two latter methods, anaerobic or aerobic organisms are supplied with electrons from electrochemically reduced, artificial mediators, e.g., methyl viologen. Reductases that do not require pyridine nucleotides and can accept electrons directly from reduced viologens are especially useful. Two examples of this type of enzyme are described which are of preparative interest. Many cells contain methyl viologen-dependent NAD(P) reductases, a large number of which have still not been characterized. A productivity number is proposed which allows different methods of bioconversion with microorganisms to be compared. The productivity numbers of compounds synthesized by the methods described in this review are often 10- to 100-fold higher than those of substances obtained by conventional techniques.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198505391
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    Syntheses with Radicals - C—C Bond Formation via Organotin and Organomercury Compounds [New Synthetic Methods (52)]Dedicated to Professor Rolf Huisgen on the occasion of his 65th birthday (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 24 (1985), S. 553-565 
    Details
    ISSN: 0570-0833
    Keywords: Free radicals ; Organomercury compounds ; Synthetic methods ; Organotin compounds ; C-C coupling ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: C—C bond formation is one of the most important synthetic steps in the construction of organic molecules. In the last few years it has been increasingly achieved by radical addition to alkenes. In such reactions the adduct radicals have to be trapped by an donor subsequent to the C—C bond formation in order to prevent polymerization. This task can be accomplished with organotin and organomercury hydrides, the use of which has led to new synthetic methods. The occurrence of radical chain reactions in which reactions take place between radicals and nonradicals is decisive for the success of the synthesis. In these cases small amounts of radical initiators suffice and numerous functional groups may be used in the C—C bond-forming reactions. The yields and selectivities of these radical reactions are often very high.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198505531
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    Enzymes as Catalysts in Synthetic Organic Chemistry [New Synthetic Methods (53)] (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 24 (1985), S. 617-638 
    Details
    ISSN: 0570-0833
    Keywords: Enzyme catalysis ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enzymes have great potential as catalysts for use in synthetic organic chemistry. Applications of enzymes in synthesis have so far been limited to a relatively small number of largescale hydrolytic processes used in industry, and to a large number of small-scale syntheses of materials used in analytical procedures and in research. Changes in the technology for production of enzymes (in part attributable to improved methods from classical microbiology, and in part to the promise of genetic engineering) and for their stabilization and manipulation now make these catalysts practical for wider use in large-scale synthetic organic chemistry. This paper reviews the status of the rapidly developing field of enzyme-catalyzed organic synthesis, and outlines both present opportunities and probable future developments in this field.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198506173
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  • 83
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    Selective Reactions Using Organoaluminum Reagents [New Synthetic Methods (54)] (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 24 (1985), S. 668-682 
    Details
    ISSN: 0570-0833
    Keywords: Organoaluminum compounds ; Synthetic methods ; Selectivity ; Beckmann rearrangement ; Rearrangement ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In addition to their high oxyphilicity, organoaluminum compounds are endowed with ambiphilic character. These properties can be successfully utilized in developing new synthetic reactions with unique selectivities. Especially noteworthy are the organoaluminum-promoted Beckmann rearrangement of oxime sulfonates, new syntheses of polyamino macrocycles via reductive cleavage of aminals and amidines by diisobutylaluminum hydride, the diastereoselective cleavage of chiral acetals by organoaluminum compounds leading to optically active secondary alcohols, allylic alcohols, and β-substituted carbonyl compounds, and biomimetic terpene syntheses. These and other examples, which illustrate the characteristics of organoaluminum chemistry, are used to demonstrate the distinct advantages of organoaluminum reagents in selective organic synthesis.
    Additional Material: 11 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198506681
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  • 84
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    Osteomalacia and altered magnesium metabolism in the X-linked hypophosphatemic mouse (1979)
    Springer
    Calcified tissue international 27 (1979), S. 19-26 
    Details
    ISSN: 1432-0827
    Keywords: Bone diseases ; Familial hypophosphatemia ; Magnesium ; Mice ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A new genetic mutant in mice,Hyp, has been proposed as a model for the human disease X-linked hypophosphatemia (the most common form of vitamin D-resistant rickets). The gene is X-linked, dominant, and produces reduced renal tubular reabsorption of phosphate, hypophosphatemia, and dwarfism. Our goal was to evaluate the skeletal changes histologically and to measure chemically the prominant blood and bone minerals to judge the suitability of this mutant as a model for the human disease. Thirteen-week-old hemizygousHyp male mice were compared with their normal littermate controls. TheHyp mice were hypocalcemic, hypophosphatemic, hypermagnesemic, and had elevated plasma alkaline phosphatase. The femur ash weighed less than half the normal ash weight but had a normal Ca:P ratio. The ash composition was high in %Na and K but low in %Mg. The mandibular incisor ash was also low in %Mg. Histologically the femur showed wide osteoid borders and wide epiphyseal plate. Microradiography revealed reduced bone density and enlarged osteocyte lacunae. Skeletal muscle samples, although smaller in theHyp mice, showed no striking alternations in inorganic or total phosphate content, dry weight (as % wet weight), or extracellular fluid space. TheHyp gene in mice seems to produce a condition similar to that of X-linked hypophosphatemia in humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441156
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    Determination of phosphorus in copper-phosphorus alloys, by GLC technique (1979)
    Springer
    Chromatographia 12 (1979), S. 212-214 
    Details
    ISSN: 1612-1112
    Keywords: Phosphorus ; Chromatography, gas-liquid ; Alloys, copper
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple, sensitive, accurate and rapid gas chromatographic method for the quantitative determination of phosphorus in copper-phosphorus alloys is described. The method is based on the chlorination of the sample with carbon tetrachloride in a sealed glass capsule at 550°C. The volatile products are introduced into the gas chromatograph after crushing the capsule in a special device. The method is very quick (ca. 20 min), involves simple manipulations and the error is about ±0.5%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02411364
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  • 86
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    Net changes in element contents of old leaves of two tropical legumes (1979)
    Springer
    Plant and soil 51 (1979), S. 247-256 
    Details
    ISSN: 1573-5036
    Keywords: Nutrient distribution ; Phosphorus ; Tropical legumes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Changes in absolute contents of nutrient elements of old leaves of two tropical pasture legumes were studied during vegetative growth in order to determine the extent of nutrient reutilization. Over a wide range of P supply, the P contents of old leaves ofDesmodium intortum cv. Greenleaf generally increased slightly with time whereas inMacroptilium atropurpureum cv. Siratro they decreased. In both species, relatively less K than P was retained in old leaves, especially in plants grown at high P supply. In desmodium, contents of N, S, Ca, Mg, B, Zn and Mn in old leaves generally increased with plant age. In Siratro, S content of old leaves decreased, but to a lesser extent than P content, and contents of N, Ca, Mg, B, Zn and Mn either changed little or increased with plant age. The lower net loss of elements from old leaves of desmodium than Siratro was associated with a greater increase over time in dry weight of old desmodium leaves. The losses of elements other than K from old leaves of Siratro and desmodium with time were relatively smaller than those reported for other species. This suggests that these legumes survive restricted supply of such elements from the roots by reducing their growth rather than by reutilizing nutrients in old leaves. By contrast, these plants can continue to grow when K supply from the roots slows or ceases by utilizing K in old tissues for growth of young tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02232887
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  • 87
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    Effect of selenium and phosphorus on the growth and chemical composition of raya (Brassica Juncea cos.) (1979)
    Springer
    Plant and soil 51 (1979), S. 485-490 
    Details
    ISSN: 1573-5036
    Keywords: Crude protein ; Fodder ; Nitrogen ; N/S ratio ; Phosphorus ; Protein ; Raya ; Selenium ; S-amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effects of Se and P on the dry matter yield and chemical composition of Raya (Brassica juncea Cos. var. R.L. 18) were studied in the green-house. The dry matter yield in P treated and untreated pots increased with Se application upto 2.5 ppm. With further increase in Se dose upto 10 ppm, dry matter yield decreased. The increase in P dose from 0 to 50 ppm increased dry matter yield in all Se treated and untreated pots but 100 ppm P rather showed decrease in dry matter yield as compared to 50 ppm P. The Se concentration increased by about 100 fold with the application of 10 ppm Se over 0 ppm Se where P was not added whereas increase was 258 and 336 times when 50 ppm and 100 ppm P was added, respectively. Inorganic, organic and total P increased with increasing Se and P. The increase in inorganic P was more than organic and total P. S and N concentration decreased with increasing Se application and increased with P application. Crude protein showed the same behaviour as N. The total sulphur-containing amino acids (which ranged from 39 to 49% of crude protein) and individual sulphur-containing amino acids like methionine (16.9 tot 20%) cysteine (9.8 to 13%) and cystine (12.3 to 15.9%) decreased with the increasing selenium but increased with increasing phosphorus. N/S ratio in the plant showed significant negative correlation with total sulphur-containing amino acids (r=−0.940**), methionine (r=−0.951**), cysteine (r=−0.929**) and cystine (r=−0.920*) whereas total sulphur in the plant showed positive significant correlation with methionine (r=0.805**), cysteine (r=0.924**) and cystine (r=0.821**).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02277570
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  • 88
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    Electronic Resource
    Changes in phosphorus concentrations in a eutrophic lake as a result of macrophyte-kill following herbicide application (1979)
    Springer
    Hydrobiologia 66 (1979), S. 105-111 
    Details
    ISSN: 1573-5117
    Keywords: Phosphorus ; herbicide ; diquat ; nutrient cycling ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phosphorus (P) concentrations in water and sediment of a highly eutrophic lake were monitored before and after application of diquat to control the macrophyte Potamogeton crispus. Only a relatively small and short-term increase in P concentration in water occurred shortly after plant die-off resulting from herbicide application. Phosphorus concentrations in shallow water sediments decreased during the summer, and those in deep water sediments increased. Although a large increase in P concentration in the water occurred in late summer, it was not attributed to diquat. No major secondary effects of herbicide application were found during this study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00032039
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  • 89
    Electronic Resource
    Electronic Resource
    Uptake and distribution of phosphorus in tomato plants (1979)
    Springer
    Plant and soil 51 (1979), S. 331-340 
    Details
    ISSN: 1573-5036
    Keywords: Deficiency ; Distribution ; Fruit ; Glasshouse ; Laminae ; Leaves ; Nitrogen ; Peat ; Petioles ; Phosphorus ; Plant ; Superphosphate ; Symptoms ; Tomato ; Uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The uptake and distribution of phosphorus was examined in tomato plants, cv. Kirdford Cross, grown in peat to which phosphate was added (P2) or omitted (P1). The plants received a liquid feed containing either a high (N2) or low (N1) concentration of ammonium nitrate. Initially, all plants were grown in peat containing an intermediate level of phosphate. There was a rapid net export of P from the leaves of plants transferred to the P1 medium resulting in deficiency symptoms before the fruit on the first truss had ripened. Most of the P absorbed by 11-week-old plants in the N1P2 and N2P2 treatments was located in the developing fruit, in the laminae of the mature leaves and in the lower parts of the stem. In the P1 treatments, the lowest fruit truss was the dominant sink for the limited supply of P, but there was also a significant concentration of P in the shoot apex and in the laminae. Increasing the supply of N to plants in the P2 treatment promoted the transport of P to the shoot and to the fruit trusses and also increased the total P uptake. However, plants in the N2 treatment required a significantly higher level of tissue P to prevent the symptoms of P deficiency occurring in the laminae. Generally, symptoms occurred in laminae of mature leaves containing less than 0.13 per cent P. Increases in concentration of tissue P in response to raising the level of applied P were greatest in the petioles of the mature leaves, and it is suggested that these petioles are the most suitable tissues for the assessment of the P status of tomato plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02197780
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  • 90
    Electronic Resource
    Electronic Resource
    Effect of phosphoros nutrition in peat on tomato plant growth and fruit development (1979)
    Springer
    Plant and soil 51 (1979), S. 341-353 
    Details
    ISSN: 1573-5036
    Keywords: Fruit development ; Glasshouse ; Growth ; Nitrogen ; Peat ; Phosphorus ; Protein ; Sand ; Tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of P nutrition on the growth of tomato plants in peat was examined. Initially, plants received an adequate supply of P and then received either nil, 0.78 or 2.34 kg superphosphate per m3 in combination with either 50 μg N/ml (N1) or 300 μg N/ml (N2) as ammonium nitrate in a liquid feed. Vegetative growth was restricted in the lower P treatmentsi.e. inhibited shoot growth, reduced duration of leaf expansion phase, thinner stems and reduced vegetative dry wt. Plants receiving N2 showed a greater restriction in growth compared with N1 plants when the P supply was limiting. P deficiency disrupted protein metabolism in the leaves, in that soluble leaf protein was reduced and trichloroacetic acid-soluble N accumulated. Flower development was accelerated by low P applications but the final numbers of flowers and the fruit-setting efficiency were reduced. Lowering the N supply reduced the fruit yield by 36 per cent while an intermediate P level reduced yields by about 15 per cent. Maximum fruit yields and good vegetative growth occurred when plants contained 0.4 per cent P or above in the mature leaves, and this value was achieved by adding the highest level (2.34 kg/m3) of superphosphate to the peat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02197781
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  • 91
    Electronic Resource
    Electronic Resource
    Effect of phosphorus on growth and iron nutrition of millet and sorghum (1979)
    Springer
    Plant and soil 51 (1979), S. 551-561 
    Details
    ISSN: 1573-5036
    Keywords: Autoradiography ; Culture solution ; Fe deficiency ; Millet ; P/Fe interaction ; Phosphorus ; Sorghum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings of millet (Pennisetum americanum (L) K. Schum var. Tift 23 DA × Tift 18 DB) and guineacorn (Sorghum bicolor (L) Moench var. RS' 702) were employed in growth chamber studies to evaluate the effects of various phosphorus (P) levels on their growth and nutrient composition. The growth medium was Hoagland solution containing 0.0, 0.1, 1.0 and 2.5 mM P and 2.2 mM ferrous sulphate-tartate solution. At the end of twenty-four days, two plants from each treatment were supplied with 0.31 μci/ml of radioactive iron (55Fe) (with the same P levels used to grow them) and then allowed to absorb the55Fe for 3 hours after which they were harvested, separated into roots and shoots. The two components were wet-ashed separately, and assayed for55Fe. The rest of the plants in Hoagland solution were also harvested, separately into roots and shoots. The components parts were also wet-ashed separately and assayed for iron (Fe), manganese (Mn), zinc (Zn), copper (Cu) and phosphorous (P). High P concentration in the growth medium inhibited55Fe absorption and translocation in both millet and sorghum but millet was more tolerant of P-induced Fe deficiency than sorghum. Millet and sorghum grew best at 1.0 and 0.1 mM P, respectively. Fe concentrations in plant declined as P levels increased; while Mn increased in both millet and sorghum with increasing P levels. Millet, however, maintained higher concentrations of Fe and Mn. The distribution patter of55Fe, regardless of P levels could be summarized as follows: Roots〉Vascular tissue〉leaf-sheaths〉leaf blade. Less55Fe was absorbed and translocated to shoots at 2.5 mM P, in millet and sorghum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02277575
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  • 92
    Electronic Resource
    Electronic Resource
    Water use and phosphorus and potassium status of wheat seedlings colonized byGaeumannomyces graminis orPhialophora radicicola (1979)
    Springer
    Plant and soil 52 (1979), S. 1-8 
    Details
    ISSN: 1573-5036
    Keywords: Gaeumannomyces ; Phialophora ; Phosphorus ; Potassium ; Water use ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The water consumption and levels of phosphorus, potassium, and total minerals were measured for wheat seedlings colonized byGaeumannomyces graminis var.tritici, Phialophora radicicola var.radicicola, orPhialophora radicicola var.graminicola. Infection byG. graminis resulted in a considerable reduction in water consumption, and reduced level of phosphorus when the supply of phosphorus to the seedlings was plentiful. Colonization byP. radicicola var.radicicola increased levels of phosphorus and potassium, but these increases varied according to the isolate of the fungus and the supply of phosphorus and potassium available to the seedlings. Colonization byP. radicicola var.graminicola resulted in reduced water consumption by the seedlings. The results are discussed in relation to stelar cell wall thickening in wheat roots colonized byP. radicicola, and the effects on nutrient uptake of mycorrhizal root systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02197726
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  • 93
    Electronic Resource
    Electronic Resource
    Effect of foliar application of phosphorus on growth and mineral composition in peanut plants (Arachis hypogaea L.) under salt-stress (1979)
    Springer
    Plant and soil 52 (1979), S. 41-48 
    Details
    ISSN: 1573-5036
    Keywords: Foliar fertilization ; Growth ; Leaf area ; Mineral composition ; Peanut ; Phosphorus ; Sand culture ; Stomatal frequency ; Yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Peanut (Arachis hypogaea L., Var. TMV-2) plants were raised in sand cultures under natural photoperiod. Salt treatment (0.4% NaCl on dry weight basis) was given 10 days after sowing. Nutrient solution was supplied 15 days after sowing to control and salinized plants. Phosphate (0.1% NaH2PO4 with 0.01% Tween-80) was sprayed to the plants to the drip point once daily from 20th to 25th day and from 30th to 35th day. The plants were harvested at 30th and 40th day for analysis. The plants grown under saline conditions showed a market reduction in growth. When phosphorus was supplied to saline plants by foliar application, there was an increase in dry weight, leaf area, stomatal frequency, and yield and the increase was more marked when the plants received phosphate for two periods. Phosphorus content decreased due to salinity which was restored by foliar spray of phosphate. With salinity, sodium accumulated while potassium and calcium were lowered. Phosphate spray decreased sodium and increased potassium and calcium in general.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02197730
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  • 94
    Electronic Resource
    Electronic Resource
    Effect of algal growth on the availability of phosphorus, iron and manganese in rice soils (1979)
    Springer
    Plant and soil 52 (1979), S. 139-149 
    Details
    ISSN: 1573-5036
    Keywords: Algal growth ; Iron ; Manganese ; Phosphorus ; Rice soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Laboratory experiments were conducted to study the effect of algal growth on the change of (I) pH, (II) available phosphorus and (III) solubility of iron and manganese content in five waterlogged alluvial rice soils of West Bengal, India. The results showed that the algal growth initially caused an increase in the soil pH, which later declined to the original value in some of the soils. The available phosphorus content decreased upto 90 days of their growth and began to increase towards the later period of incubation. The drastic fall of water soluble plus exchaneable manganese content of the soils due to algal growth was accompanied by similar increase in reducible manganese content. No appreciable change in water soluble plus exchangeable ferrous iron content was encountered but theN-NH4OAC(pH 3) extractable iron due to algal growth progressively decreased with the progress of the incubation period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02184556
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  • 95
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    Electronic Resource
    Influence of soil moisture regimes and organic matter application on the extractable Zn and Cu content in rice soils (1979)
    Springer
    Plant and soil 53 (1979), S. 203-213 
    Details
    ISSN: 1573-5036
    Keywords: Alluvial soil ; Alternate waterlogged and saturated ; Copper ; Immobilization ; Interaction ; Iron ; Manganese ; Organic matter ; Phosphorus ; Reduction ; Rice ; Saturated ; Waterlogged ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A laboratory incubation experiment was conducted to study the influence of three moisture regimes,viz (i) waterlogged (W1), (ii) alternate waterlogged and saturated (W2) and (iii) continuous saturated (W3) and two levels of organic matter application,viz (i) 0 (T1) and (ii) 0.5% of the soil (T2) in their all possible combinations on the extractable (N NH4OAC, pH 7.0) zinc and copper in three lowland alluvial rice-growing soils of West Bengal (India). The results showed that the extractable zinc and copper content in soils recorded marked decrease on incubation under all the moisture regimes, but the same was most prominent under the continuous saturated moisture regime (W3), followed by waterlogged (W1) and alternate waterlogged and saturated (W2) moisture regimes. Application of organic matter brought about further decrease in the content of these elements. Organic matter application combined with saturated moisture regime brought about the greatest decrease both in zinc and copper content. The microbiological immobilisation and the antagonistic effect of increased concentration of extractable iron, manganese and phosphorus have been suggested as the possible reasons for the observed decrease of the content of extractable zinc and copper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02181891
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  • 96
    Electronic Resource
    Electronic Resource
    Phosphorus in a model pond study: I sediment selection and preparation (1979)
    Springer
    Hydrobiologia 63 (1979), S. 11-15 
    Details
    ISSN: 1573-5117
    Keywords: Fertilizer ; Nutrients ; Soluble Phosphate ; Equilibrium Phosphate Concentration ; Phosphorus ; Pond ; Sediment ; Erosion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We chose two surface soils with contrasting textures as model sediments for a model pond study. One soil, a calcareous clay, had a relatively high natural phosphate content and a large phosphate adsorption capacity. The second soil, a non calcareous loam, had a relatively low natural phosphate content and a small phosphate adsorption capacity. Chemical characteristics of both soils were roughly proportional to mineral surface area. Pasture sites of each soil were tilled to a depth of 15 cm and two plots at each site were fertilized by hand with triple superphosphate. A third plot at each site was left unfertilized. After fertilization the plots were mechanically mixed and left fallow for 2 to 3 months. Then the plots were resampled and equilibration phosphate concentrations were determined again. Results showed significant phosphate fixation by the clay soil but no fixation by the loam soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021012
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  • 97
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    Electronic Resource
    Pyrolysis of Sulfones as a Synthetic Method [New synthetic methods (28)]We shall deal here only with those sulfones whose sulfur atoms are directly bonded to two C atoms. (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 18 (1979), S. 515-529 
    Details
    ISSN: 0570-0833
    Keywords: Pyrolysis ; Sulfones ; Synthetic methods ; Ring contraction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclic sulfoness containing structural elements such as aromtic rings, heteroatoms. functional groups, and further SO2-groups as ring members decompose on heating with cleavage of SO2 and formation of a new C—C bond. In the last decade this “sulfone pyrolysis” has been expanded into a generally applicable method even allowing the synthesis of sterically strianed medium-membered and multi-membered cyclic and polycyclic systems containing aromatic ring. By the pyrolysis of sulfones which are only unilateally activated by benzyl moieties, aromatic systms can be bridged by —(CH2)n chains of any desired length. In addition, —(CH2)— chains can be split off together with two SO2 molecules, with recombination of the remaining centers, resulting in ring contraction by four to n atoms. However, sulfone pyrolysis is of importance not only as a ring-contraction method but as a crucial final step in the synthesis of multi-membered hydrocarbon cycles, e.g. of the phane type.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197905151
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  • 98
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    Electronic Resource
    Capto-dative Substituent Effects in Syntheses with Radicals and Radicophiles [New synthetic methods (32)]Capto-dative Substitution Effects, Part 5. - Part 4: [67].Dedicated to the double anniversary: 100 years Wurster's salts and 50 years Paneth's radical reactions with mental mirrors (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 18 (1979), S. 917-932 
    Details
    ISSN: 0570-0833
    Keywords: Donor-acceptor systems ; Substituent effects ; Free radicals ; Radicophiles ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 100 yers old Wurster's salts have long been recognized as compounds with redical cations. Their unusual stabilization derives partly form capto-dative (cd) substitution. This principle is now discussed as one factor of radical stabilization and it is applied to simple methine derivatives. cd-Substitution has synthetically useful applications: cd-substituents on a carbon atom allow its selective dehydrodimerization. Olefines with geminal and thus cross-conjugated cd-substituents are “radicophilic” and permit twofold carbon radical addition. cd-Substituted olefines are useful antioxidants, polymerization inhibitors and are promising agents in the control of biological radical reactions. Generally, many reactions of cd-substituted molecules appear to involve radicals.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197909171
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  • 99
    Electronic Resource
    Electronic Resource
    Triphase Catalysis [New synthetic methods (27)] (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 18 (1979), S. 421-429 
    Details
    ISSN: 0570-0833
    Keywords: Triphase catalysis ; Catalysis ; Synthetic methods ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triphase catalysis (TC) has recently been introduced as a unique form of heterogeneous catalysis in which the catalyst and each of a pair of reactants are located in separate phases. Based on this concept, new synthetic methods have been developed for aqueous phase-organic phase reactions using a solid phase catalyst. Although it is only at an early stage of development, TC shows considerable potential for practical use. Our mechanistic understanding of these highly complex catalytic systems is at present very limited and detailed examination will be required before their relationship to phase-transfer, micellar, and interfacial catalysis becomes clear.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197904213
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  • 100
    Electronic Resource
    Electronic Resource
    Catalytic Reactions with Hydrosilane and Carbon Monoxide [New synthetic methods (30)] (1979)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 18 (1979), S. 837-846 
    Details
    ISSN: 0570-0833
    Keywords: C-C coupling ; Synthetic methods ; Catalysis ; Silanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reagent hydrosilane/carbon monoxide opens up new possibilities for organic synthesis. Four cases will be discussed: 1. The reaction of olefins with hydrosilane (trialkylsilane) and carbon monoxide in the presence of Co, Ru, and Rh complexes leads to enol silyl ethers having one more carbon atom that the olefins. 2. Cyclic ethers underto carbonylative ring opening to ω-siloxyaldehydes when reacted with hydrosilane and carbon monoxide in the presence of Co2(CO)8 as catalysts 3. Aldehydes are catalytically converted into the next higher α-siloxyaldehydes or 1,2-bis(siloxy)alkenes depending on the reaction conditions used. 4. The reaction of alkyl acetates proceeds in various ways depending on the nature of the alkyl group; enol silyl ethers or alkenes are optained.-Mechanisms of these Co2(CO)8 catalyzed reactions using hydrosilane and carbon monoxide are discussed in which HCo(CO)n or R3SiCo(CO)nL function as catalytically active agents. With these species there are four types of catalytic cycles.-The synthetic possibilities of these catalytic reactions have still not been fully explored.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.197908371
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