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  • 1990-1994  (24)
  • 1950-1954
  • 1925-1929
  • Chemistry  (20)
  • kiwifruit  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Influence of anions on the potassium status and productivity of kiwifruit (Actinidia deliciosa) vines (1991)
    Springer
    Plant and soil 133 (1991), S. 209-218 
    Details
    ISSN: 1573-5036
    Keywords: Key words ; anions ; chloride ; flowers ; fruit yield ; kiwifruit ; potassium ; sulphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of K fertiliser (160 kg ha-1) applied with Cl- or SO4 2- as the accompanying anion on the K nutrition of kiwifruit (Actinidia deliciosa var. deliciosa) were assessed in a field experiment, using vines with varying degrees of K deficiency. Leaf K concentrations in spring were significantly higher for vines receiving KCl, compared to those receiving K2SO4. This effect did not interact significantly with the degree of K deficiency, and persisted for about 6 weeks. Subsequently there was no significant difference between the leaf K concentrations for the vines receiving KCl or K2SO4. Applying K as KCl increased the leaf Cl concentration, especially in spring, while applying K as K2SO4 had no significant effect on the leaf S concentration at that time. These results implied a greater requirement for organic acid anions for K+ uptake from K2SO4 than from KCl, and the importance of organic acid anions for K+ uptake from different sources of K fertiliser is discussed. This transient effect of the accompanying anion on leaf K status was associated with large effects on flowering, and fruit yields were about 28% higher for plants receiving KCl rather than K2SO4. The effects on growth and tissue nutrient composition of varying the concentrations of Cl-, NO3 -, SO4 2- and H2PO4 - around the roots of kiwifruit vines were examined in a solution culture experiment. For H2PO4 -, plant growth was very similar over a wide range of rates of addition. For the other anions, the range between deficiency and ‘toxicity’ was clearly delineated. For Cl- and NO3 -, toxicity was associated with high tissue concentrations of Cl and N, respectively, and was consistent with competition for uptake between Cl- and NO3 -. However, for SO4 2-, toxicity was associated with only a small increase in the tissue S concentration relative to that associated with maximum growth, and appeared to result more from effects on uptake of other anions and cations rather than from direct effects of high tissue S concentrations. It is concluded that the sensitivity of kiwifruit to the anion accompanying K+ in fertiliser may be related to the unusually high requirement for Cl previously reported for this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009193
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  • 2
    Electronic Resource
    Electronic Resource
    Fate of 15N-labelled nitrogen fertilizer applied to kiwifruit (Actinidia deliciosa) vines (1992)
    Springer
    Plant and soil 147 (1992), S. 49-57 
    Details
    ISSN: 1573-5036
    Keywords: ammonium ; field ; kiwifruit ; 15N ; nitrogen fertilizer ; recovery ; soil nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The fate of 15N-labelled ammonium fertilizer applied once to six-year-old field-grown kiwifruit (Actinidia deliciosa ‘Hayward’) vines was measured over three years. The three main treatments were nitrogen (N) applied singularly at 100 or 200 kg N ha−1 in early spring (two weeks before bud burst) or split with 100 kg N ha−1 (unlabelled) in early spring and 100 kg N ha−1 (15N-labelled) ten weeks later. All N treatments were applied to vines with a history of either 50 or 200 kg N ha−1 yr−1. For three years after 15n application, components of the vines and soil (0–600 mm depth) were sampled at harvest in late autumn and the N and 15N contents determined. By the first harvest, all plant uptake of 15N had occurred and this represented 48–53% of the 15N applied. There was no significant effect of current N fertilizer treatment or of N history on 15N recovery by vines. Removal of 15N in harvested fruit was small at 5–6% in the first year and 8% over 3 years. After 2–3 years, most plant 15N occurred in the roots and this component declined only slowly over time. In contrast, there was a large temporal decline in 15N in above-ground plant components due to the annual ‘removal’ in leaf fall and pruning. An associated experiment showed that when 15N-labelled prunings and leaves were mulched and returned to the soil, only about 9% was recovered by plants within 2 years. Almost all remaining mulched material had been immobilised into the soil organic N. In all treatments, about 20% of the added 15N remained in soil at the first harvest. This was almost entirely in organic fractions (〈0.4% in inorganic N) and mostly in the surface 150-mm layer. The 15N content in soil changed little over time (from 20 to 17% between the first and third harvests respectively) and indicated that most of the N had been immobilised into stable humus forms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009370
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  • 3
    Electronic Resource
    Electronic Resource
    Fate of 15N-labelled nitrogen fertilizer applied to kiwifruit (Actinidia deliciosa) vines (1992)
    Springer
    Plant and soil 147 (1992), S. 59-68 
    Details
    ISSN: 1573-5036
    Keywords: kiwifruit ; 15N ; plant uptake ; remobilisation ; temporal changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Temporal changes in the nitrogen (N) and 15N content of various components of six-year-old kiwifruit (Actinidia deliciosa ‘Hayward’) vines which had received 15N-labelled ammonium fertilizer were measured. The fertilizer was applied singularly at 100 or 200 kg N ha−1 in early spring (two weeks before bud burst) or split with 100 kg N ha−1 (unlabelled) in early spring and 100 kg N ha−1 (15N-labelled) ten weeks later. All treatments were applied to vines with a history of either 50 or 200 kg N ha−1 yr−1. The N concentration of leaf and fruit tissue was generally lower in the 100 kg N ha−1 treatment than in the 200 kg N ha−1 treatments and this effect was greater than that of N fertilizer history. During the first 8 weeks after bud burst there was a rapid accumulation of N in leaves (ca. 80 kg N ha−1). Analysis of xylem sap at 4 weeks after bud burst revealed that about 60% of the N utilised for new growth was from remobilisation of N stored within the vines and about 40% from soil and fertilizer N. This was unaffected by rate of N application. Plant uptake of added 15N was rapid and almost complete within 10 weeks of application in either early spring or early summer. Initially, most 15N was present in the leaf and root components but these subsequently declined due to translocation into other components of the vine. The decline in leaf 15N coincided with an equivalent accumulation of 15N in the fruit. The 15N enrichment of the ‘annual’ components (leaves, fruit and current-season's shoots) was about twice that of the structural components (one-year-old shoots, cordon, stem and structural roots) during the first year after application. By the third year the 15N concentration of the annual components had declined to similar levels to that of the structural components. These changes were used to estimate the annual throughput of N from soil in vines which received no N fertilizer in years 2 and 3 at 50% of total above-ground N and only 7% in roots. This was equivalent to about 120 kg N ha−1 yr−1. Where fertilizer N (200 kg ha−1) was applied in year 2 the annual throughput of N from soil and fertilizer was about 170 kg N ha−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00009371
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  • 4
    Electronic Resource
    Electronic Resource
    The development and effects of nitrogen deficiency in field-grown kiwifruit (Actinidia deliciosa) vines (1990)
    Springer
    Plant and soil 129 (1990), S. 173-182 
    Details
    ISSN: 1573-5036
    Keywords: chloride ; kiwifruit ; leaf nitrogen concentration ; nitrate ; plant density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The development and effects of nitrogen (N) deficiency in kiwifruit (Actinidia deliciosa ‘Hayward’) vines planted at three densities (25.0, 12.5 and 8.33 m2 vine−1) were examined in a long term (1982 to 1989) field experiment in which N was applied at rates from 0 to 200 kg N ha−1 year−1. The rate of applied N significantly affected leaf N concentrations every year from 1985 onwards, and the average leaf N concentrations declined throughout the experiment. Fruit N concentrations varied significantly with the level of applied N as early as 1986. The average fruit N concentrations varied strongly between years, and were inversely proportional to the fruit number (per m2), indicating that, after fruit set, growth of individual fruit was relatively insensitive to the vine N status. Effects of N supply on fruit yields resulted mostly from changes in fruit number (per m2). For vines planted at the high density, fruit yields responded significantly to the level of applied N each season from 1986 onwards. In any year, maximum fruit yields for vines planted at the high density were associated with leaf N concentrations (20 weeks after bud burst) of at least 1.8 mmol g−1. For vines planted at low density, significant yield responses to the level of applied N were not recorded until 1988, and maximum yields in that year were associated with leaf N concentrations of at least 1.4 mmol g−1. The delayed expression of effects of N deficiency on fruit yields for vines planted at low density appeared to follow a shift in partitioning of resources in favour of fruit growth. This shift in partitioning did not appear to be sustainable, and by 1989 the fruit yield response to applied N continued to the highest N level tested. In that year, the leaf N concentration associated with maximum yield was 1.8 mmol g−1, the same as that recorded throughout the experiment for the vines planted at high density. In the last two seasons of the experiment, leaf necrosis developed extensively on vines receiving less than the highest rate of N. This necrosis appeared to be premature senescence resulting from N deficiency. Leaf chloride (Cl) concentrations increased significantly with increasing severity of N deficiency, but were never more than those associated with Cl toxicity. While N supply significantly affected fruit firmness immediately post-harvest, there were no significant effects on fruit firmness after 12–20 weeks storage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00032410
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  • 5
    Electronic Resource
    Electronic Resource
    Structure of a rhombohedral R6 insulin/phenol complex (1992)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 14 (1992), S. 401-408 
    Details
    ISSN: 0887-3585
    Keywords: X-ray diffraction ; allosterism ; zinc/phenol interaction ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Hexameric insulin has been crystallized from different conditions ina variety of crystalline modifications. In the presence of ∼1%phenol and at a pH of 8.5, a new rhom-bohedral form is produced, space group R3, a = 79.92 Åand c = 40.39 Å, in whichthe asymmetric unit consists of a dimer. The structur has been solved and refined, using data between 8.0 and 2.5 Å resolution, to a residual of0.157. The two monomers in the asymmetric unit have nearly identical R conformations, that is, residues Bl through B8 are α-helical, producing a continuous α-helix from Bl through B19. A phenol molecule is hydrogen bonded to the carbonyl oxygen of A6 Cys of each monomer. Small differences in conformation and the final (2Fo-Fc) and difference electron density maps suggest that an additional phenol molecule is coordinated to one of the two zinc ions.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340140309
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  • 6
    Electronic Resource
    Electronic Resource
    Molecular structure, morphology, and antioxidant consumption in medium density polyethylene pipes in hot-water applications (1992)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 32 (1992), S. 649-657 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Changes in polymer structure and antioxidant concentration have been systematically studied as functions of temperature, hoop stress, exposure time, and location in pipe wall on pressure tested pipes of medium density polyethylene. The pressure tests have been performed with water as the internal medium and air as the external medium at temperatures in the range 80 to 105°. Infrared spectroscopy shows that oxidation is initiated at the inner wall surface just prior to the onset of the so-called stage III fracture. X-ray diffraction and size exclusion chromatography show that oxidation involves only the amorphous phase and results in a significant molar mass reduction. The near-inner-wall material exhibits a 10% reduction in mass average molar mass before the onset of stage III fracture and thereafter a more dramatic decrease. Oxidation induction time measurements by differential scanning calorimetry show that the antioxidant concentration is almost twice as high in the center of the wall as in the near-inner-wall and outer-wall material of the unexposed pipe, that the loss of antioxidant is anomalously rapid at the beginning of the high temperature exposure, and that the antioxidant concentration profile gradually becomes more skewed towards the outer wall on prolonged exposure. The data presented in this paper are used in a parallel paper for modeling purposes.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760321003
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  • 7
    Electronic Resource
    Electronic Resource
    Molecular structure, morphology, and antioxidant- consumption in polybutene-1 pipes in hot-water applications (1993)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 33 (1993), S. 303-310 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Pipes of isotactic polybutene-1 (PB) have been exposed to internal water and external air in pressure tests at 105°C. The pipes exposed to different internal pressures exhibited different failure mechanisms, referred to as stages I, II, and III. Samples taken from these pipes have been analyzed by infrared (IR) spectroscopy, wide-angle X-ray scattering (WAXS), size exclusion chromatography (SEC), and differential scanning calorimetry (DSC). IR spectroscopy and WAXS confirmed that thermal oxidation of the amorphous part of the polymer accompanied the onset of stage III. Thermal oxidation led to extensive molar mass reduction and to a significant increase in mass crystallinity and melting peak temperature. Extensive and visible degradation in pipes failing according to stage III was confined to so-called “oxidation spots.” The latter were first formed at the outer wall and propagated inwards, finally constituting approximately 50% of the wall thickness. The antioxidant concentration profiles obtained by DSC were always symmetrical and were successfully adapted to a previously developed model. It was shown that migration of the antioxidant was the dominant loss mechanism, that the diffusion coefficient was constant through the pipe wall, and that the evaporative loss to the external air was marginally greater than the loss to the internal water phase. Chemical consumption of the antioxidant was found to be negligible.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760330510
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  • 8
    Electronic Resource
    Electronic Resource
    Modeling of antioxidant loss from polyolefins in hot-water applications. I: Model and application to medium density polyethylene pipes (1992)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 32 (1992), S. 658-667 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: This paper is the first in a series of related papers describing the application of a diffusion/reaction model to the loss of antioxidants from polyolefins in hot-water applications. The model, which is derived in detail, describes the time evolution of antioxidant concentration profiles in the exposed material in terms of adjustable parameters. The parameters describe the rates of diffusion, evaporation, extraction, and chemical reaction of antioxidant. Parameter values are determined by least-squares fitting of the calculated concentration profiles to experimental profiles. The model is applied to a commercial medium density polyethylene pipe material, where antioxidant concentration data from thermal analysis is available for water/air (internal/external) exposure at three temperatures. A comparison of parameter values with literature data is undertaken. The temperature dependence of the parameters is considered and activation energies are compared with literature values. The relative importances of the loss mechanisms are discussed. The effect of boundary conditions on parameter values is considered by application of the model to a limited amount of available data for air/air and water/water exposures. The results indicate that for water/air exposure, extraction by the water phase is the dominating loss mechanism.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760321004
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  • 9
    Electronic Resource
    Electronic Resource
    Molecular structure of cyclo[-(D-Val-L-Hyi-L-Val-D-Hyi)2-] revealed by X-ray analysis (1992)
    New York : Wiley-Blackwell
    Biopolymers 32 (1992), S. 757-764 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The crystal structure of a synthetic analogue of valinomycin, cyclo [-(D-Val-L-Hyi-L-Val-D-Hyi)2-] (octa-meso-valinomycin) (I) (C40H68N4O12 · 1.5 · C4H8O2, Mr = 937.01 + 88.10), has been determined. Crystals grown from dioxane are monoclinic, space group P21/a, with cell parameters a = 21.487(8), b = 16.836(5), c = 16.089(4) Å, β = 111.70(4), and Z = 4. The atomic coordinates for nonhydrogen atoms were refined in the anisotropic thermal motion approximation. H atom positions were included in the structure factor calculations at their geometrically expected positions. Values of the standard and weighted R factors after refinement are 0.11 and 0.13, respectively. The conformation of the depsipeptide crystallized from dioxane is different from that crystallized from chloroform (II). The molecule adopts a rectangular shape with two type IV β-turns containing a hydrogen bond and possesses pseudorotational symmetry. The side chains are located on the molecular periphery. The orientation of the carbonyl groups of the molecule is not conducive for efficient metal-ion coordination and in the observed conformation cannot behave as an ionophore.In the crystal the molecules form infinite chains parallel to the c axis, and are stabilized by two intermolecular hydrogen bonds that are shorter and have better geometry than the intramolecular hydrogen bonds.A φ/Ψ plot for dodecadepsipeptides with a (DLLD)3 sequence has well-defined areas for Val and Hyi residues only in cases when the crystals have been grown from nonpolar or medium-polar solvents. The Φ/Ψ plot for octadepsipeptides crystallized from chloroform (II) shows this behavior also. There also is a correlation between the polarity of the solvent from which crystals of octa-meso-valinomycin or valinomycin analogues with a (DLLD) sequence of configuration have been grown and the number of the intramolecular hydrogen bonds that are formed. The more polar the solvent the fewer the number of intramolecular hydrogen bonds.Empirical energy calculations on octa-meso-valinomycin indicate that for isolated molecules, the energy of the bracelet form (II) is 4.7 kcal/mole lower than that of the rectangular form (I).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360320705
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  • 10
    Electronic Resource
    Electronic Resource
    The structure of a rhombohedral R6 insulin hexamer that binds phenol (1992)
    New York : Wiley-Blackwell
    Biopolymers 32 (1992), S. 441-445 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Different hexameric forms of insulin have been crystallized from a variety of conditions. In the presence of 1% phenol, 1.0 M sodium chloride, and at a pH of 8.5, a rhombohedral form is produced with two monomers in the asymmetric unit, space group R3, a = 79.92 Å and c = 40.39 Å. The structure has been solved and refined, using data between 8.0 and 2.5 Å resolution, to a residual of 0.157. Each of the monomers adopts an R conformation, that is residues B1-B8 are α-helical. As a result of the T to R transition, an elliptical cavity is created between symmetry-related monomers and is occupied by a phenol molecule. A region of density within bonding distance to one of the zinc ions has been interpreted as an additional phenol molecule.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360320422
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