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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 16 (1993), S. 45-51 
    ISSN: 1432-0789
    Keywords: Deep tillage ; N balance calculations ; N immobilization ; N mineralization potential ; Organic matter equilibria ; Active N pool ; Stable N pool
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The depth of ploughing has increased in West Germany during the last three decades. Before the 1960s, the depth of the Ap horizon rarely exceeded 25 cm; in the early 1980s it reached about 35 cm on average but it has remained constant since that time. In 1989, the total N content of 105 plots in the southern Niedersachsen loess area was measured after deepening of the plough layers. The N content of the samples was compared with that of earlier samplings (1) before deeper tillage in the 1960s, the 1970s, and the 1980s; and (2) in 1983. Directly after the deeper ploughing, the N content of the topsoil decreased, presumably due to dilution with the subsoil material. Mass balance calculations for total N in 1989 showed that the phase of N accumulation can take 20 years or more. Within two decades, up to 2000 kg N ha-1 was immobilized in the soil organic matter. Recent incubation experiments with disturbed soil indicated that the N mineralization capacity was reestablished in all soils and is now similar to that of the early (1960s and 1970s) and more recent (1980s) deepened plough layers. Undisturbed soil material incubated in plastic tubes showed a significantly reduced net mineralization at water contents above 65% of the waterholding capacity, particularly in the lower part (15–30 cm) of the Ap horizon. This study suggests that N accumulated in the deep plough layers cannot contribute noticeably to net N mineralization in loess soils during the growing season.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 53 (1986), S. 195-202 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract A theory of early visual information processing proposed by Marr and co-workers suggests that simple cortical cells may be involved in the detection of zero crossing in the retinal output. We have tested this theory by using pairs of adjacent edges (staircases stimuli) and recording from edge-specific simple cells in cat striate cortex. The zero crossing hypothesis gives rise for such stimuli to non-obvious predictions that were generally confirmed by the experiment.
    Type of Medium: Electronic Resource
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  • 13
    ISSN: 1432-0789
    Keywords: Key words Microbial N ; Immobilization ; Remobilization ; NH4+ fixation ; Exchangeable NH4+
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In 1991, field experiments on loess (with winter wheat) and sandy soils (with summer barley) were conducted to study N dynamics in the microbial biomass and non-exchangeable NH4 +. The measurements showed a mass change in microbial N, with a maximum increase of 100 kg N ha–1 30 cm–1 from March to July in the loess soil, and a change for only 1 month (May) in the sandy soil. Plots treated with conventional levels of N fertilizer (213 kg N ha–1 on a loess soil to winter wheat and 130 kg ha–1 on the sandy soil to summer barley), reduced levels of N (83% and 62% of the conventional N application), or no N showed no consistent fertilizer N effect on microbial biomass N. From March to July, non-exchangeable NH4 + in loess soils under winter wheat decreased by 110 kg N ha–1 30 cm–1 in conventionally fertilized plots and by 200 kg N ha–1 30 cm–1 in a plot with no N fertilizer. After harvest, the pool of non-exchangeable NH4 + increased due to increasing mineral N concentrations in the soil.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 8 (1989), S. 219-226 
    ISSN: 1432-0789
    Keywords: Denitrification ; Acetylen inhibition technique ; 15N technique ; Organic residues ; Mineral fertilization ; Irrigation ; Temperate climate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Denitrification N losses can be determined by three methods. The first is by estimating the non-recovery of 15 N-labelled compounds (15N-balance method). Using this method, denitrification losses are deduced from the balance of an N budged (15N-labeled fertilizer), having accounted for transformations in soil, plant uptake, and leaching losses. The evolution of gaseous N from native soil N is not taken into account by this procedure. Studies on arable land with annual crops in the temperate zone have shown that of the fertilizer N applied, about 20–500% (10–70 kg N* ha−1) is not recovered at the end of the growth period. The second method of determining denitrification N losses is by in situ field measurement of 15 N 2 and 15 N 2 O production. Under this procedure, 15N-enriched N is applied to a plot and the denitrification N losses are determined by covering the soil. The method allows a quantitative estimate of the relative contributions to the emitted gas by both the original enriched source and the native soil N. N-evolution rates measured on arable land under a temperate climate are approximately the same order of magnitude as the N losses estimated by the non-recovery of 15 N method. The third measuring procedure is based on the acetylene inhibition phenomenon. This principle uses the inhibition of bacterial N2O reduction to N2 in the presence of acetylene (C2H2). The methoddetermines the denitrification of all NO3 −-N irrespective of its source. Measurements on classical crop production systems show maximum N losses in the temperate climate of about 20–30 kg N* ha−1 during the growth period of annual crops. A similar level of denitrification is estimated for grassland sites under the same climate. In the subtropics (mediterranean climate with hot summers and mild winters), from both intensively cultivated arable land and grassland sites, N losses may exceed 200 kg* ha−1 year−1. Without the use of irrigation the denitrification flux is negligible in spite of the high temperatures in this climate.
    Type of Medium: Electronic Resource
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  • 15
    ISSN: 1432-1076
    Keywords: Gastroenteritis ; Infants ; Rotavirus ; Adenovirus 31 ; Genome type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An an infants' ward, gastroenteritis occurred in five children in two groups, probably by nosocomial spead of adenovirus 31 (three cases) and adenovirus 31 + rotavirus (two cases). The infants recovered well. The DNA of adenovirus 31 isolates was analysed with ten restriction endonucleases and found identical for all five strains, but different from the prototype.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 45 (1993), S. 195-196 
    ISSN: 1432-1041
    Keywords: Digoxin ; Amiloride ; Canrenoate ; inotropism ; healthy volunteers ; potassium sparing diuretics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
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  • 17
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    Unknown
    Berlin : Periodicals Archive Online (PAO)
    Deutsche Zeitschrift für Philosophie. 21:9 (1973) 1080 
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 12 (1964), S. 442-467 
    ISSN: 0942-0940
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The authors present a thorough report of the previously described treatment for total scalping and a critical review of the long terra results. The 68 cases, published since 1837, are tabulated together with one personal case. Since the introduction of grafting techniques the mortality of this severe injury, which is almost exclusively seen in women, has dropped from 50% to 2%. If operation is performed within the first few hours after injury, the recipient periosteum can usually be successfully covered with split-thickness grafts taken from the scalp. Some authors have even succeeded under favourable circumstances in regrafting the entire scalp. In the authors' case the prepared and reapplied scalp became completely necrotic after 14 days and had to be removed leaving a large area of uncovered periosteum. Within three months, after the bared area of periosteum had been covered by the natural development of scalp granulation tissue, closure with secondary split-thickness grafts was successful.
    Abstract: Résumé Les auteurs présentent un rapport complet sur le traitement du scalp total et une revue critique de ses résultats à long terme. Il est fait un tableau des 68 cas publiés depuis 1837, et d'un cas personnel. Depuis l'introduction des techniques de greffe, la mortalité de cette lésion grave, que l'on rencontre presque exclusivement chez les femmes, est tombée de 50% à 2%. Si l'opération est réalisée dans les premières heures après la lésion, il est généralement facile de couvrir le périoste receveur avec des greffons «fenteépaisseur» prélevés sur le scalp. Quelques auteurs ont mÊme obtenu des résultats dans des circonstances favorables, en regreffant le scalp entier. Dans le cas présenté par l'auteur, le scalp, préparé et greffé, devint complètement nécrotique après 14 jours. Il dut Être enlevé, laissant une grande surface de périoste non couverte. Dans les 3 mois suivants, après que la surface de périoste mise à nu eut été couverte par un développement naturel de tissu de granulation du scalp, on réalisa avec succès une seconde opération avec des greffons secondaires «splitthickness».
    Notes: Zusammenfassung Die Verfasser geben einen ausführlichen Bericht über die bisher beschriebenen Therapieversuche bei Totalscalpierungen und eine kritische Beurteilung ihrer Erfolgsaussichten. Es wurden 68 seit 1837 veröffentlichte FÄlle und ein eigener kasuistischer Beitrag tabellarisch erfa\t. Durch Einführung des Transplantationsverfahrens wurde die MortalitÄt dieser schweren, fast ausschlie\lich bei Frauen beobachteten Verletzung von 50% auf 2% gesenkt. Erfolgte die operative Versorgung innerhalb der ersten Stunden, so konnte bei erhaltenem Periost die Transplantation meist auch mit vom Scalp entnommenen Spalthautlappen erfolgreich durchgeführt werden. Einigen Autoren gelang es sogar unter günstigsten UmstÄnden, den Scalp insgesamt wieder zur Anheilung zu bringen. Im eigenen Falle mu\te infolge eines grö\eren Periostdefektes der prÄpariert wieder aufgelegte Scalp infolge völliger Nekrotisierung nach 14 Tagen entfernt werden. Innerhalb 3 Monaten gelang dann, nachdem sich auch in den periostentblö\ten Bezirken unter dem alsnatürlichen Verband wirkenden Scalp Granulationsrasen entwickelt hatten, die Deckung mit sekundÄren Spalthauttransplantaten.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 284-286 (June 1998), p. 411-418 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 135 (1967), S. 20-32 
    ISSN: 0005-2736
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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