Litterfall decomposition of coffee shaded with Tectona grandis or in full sun

ABSTRACT Litterfall is an important source of soil nutrients, but its decomposition can be affected by the crop system used. The objective of this study was to evaluate litterfall decomposition and macronutrient stocks in coffee crop systems in shaded (SHCS) environments and those in full sun (FSCS). The experiment was conducted on a rural property in Cacoal, state of Rondônia, Brazil, in a 2 × 6 factorial scheme with two crop systems (SHCS and FSCS), and six litterfall decomposition evaluation times (0, 30, 60, 180, 300, and 360 days after the litterfall was returned to the soil (DAL)), with seven replicates. The constant of decomposition (k), half-life time (t1/2) at 360 DAL, and phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and nitrogen (N) concentrations of the remaining litterfall were determined at each evaluation time. The litterfall in the SHCS had a greater weight loss and constant of decomposition and a lower half-life time at the last evaluation, and the weight loss increased as a function of decomposition time. The litterfall stocks of macronutrients N, P, K, Ca, and Mg showed a linear decrease throughout the decomposition time, and increases in sulfur stock were found at the last evaluation.

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Covalent Complexes Between Low Molecular Weight Heparin Fragments and Antithrombin III – Inhibition Kinetics and Turnover Parameters

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657333 ◽

1983 ◽

Vol 49 (02) ◽

pp. 109-115 ◽

Cited By ~ 4

Author(s):

M Hoylaerts ◽

E Holmer ◽

M de Mol ◽

D Collen

Keyword(s):

Molecular Weight ◽

Half Life ◽

Low Molecular Weight Heparin ◽

Antithrombin Iii ◽

Factor Xa ◽

Life Time ◽

Low Molecular Weight ◽

High Affinity ◽

Plasma Half Life ◽

Covalent Complex

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).

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Simultaneous optimization of activity and stability of xylose reductase from D. nepalensis NCYC 3413 using statistical experimental design

Protein and Peptide Letters ◽

10.2174/0929866527666201103145246 ◽

2020 ◽

Vol 27 ◽

Author(s):

Shwethashree Malla ◽

Sathyanarayana N. Gummadi

Keyword(s):

Half Life ◽

Specific Activity ◽

Enzyme Stability ◽

Reductase Activity ◽

Xylose Reductase ◽

Life Time ◽

Economic Feasibility ◽

Simultaneous Optimization ◽

Physical Parameters ◽

Statistical Experimental Design

Background: Physical parameters like pH and temperature play a major role in the design of an industrial enzymatic process. Enzyme stability and activity are greatly influenced by these parameters; hence optimization and control of these parameters becomes a key point in determining the economic feasibility of the process. Objective: This study was taken up with the objective to optimize physical parameters for maximum stability and activity of xylose reductase from D. nepalensis NCYC 3413 through separate and simultaneous optimization studies and comparison thereof. Method: Effects of pH and temperature on the activity and stability of xylose reductase from Debaryomyces nepalensis NCYC 3413 were investigated by enzyme assays and independent variables were optimised using surface response methodology. Enzyme activity and stability were optimised separately and concurrently to decipher the appropriate conditions. Results: Optimized conditions of pH and temperature for xylose reductase activity were determined to be 7.1 and 27 ℃ respectively, with predicted responses of specific activity (72.3 U/mg) and half-life time (566 min). The experimental values (specific activity 50.2 U/mg, half-life time 818 min) were on par with predicted values indicating the significance of the model. Conclusion: Simultaneous optimization of xylose reductase activity and stability using statistical methods is effective as compared to optimisation of the parameters separately.

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Radical Intermediates in Photochemical and Redox Initiated Decomposition of Thioazo Compounds(an EPR and Cyclovoltammetric Study)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19970855 ◽

1997 ◽

Vol 62 (6) ◽

pp. 855-865 ◽

Cited By ~ 3

Author(s):

Katarína Erentová ◽

Vladimír Adamčík ◽

Andrej Staško ◽

Oskar Nuyken ◽

Arming Lang ◽

...

Keyword(s):

Decomposition Rate ◽

Half Life ◽

Spin Trap ◽

Solvent Molecule ◽

Life Time ◽

Radical Intermediates ◽

Reactive Radicals ◽

Induced Decomposition

The cathodically and photochemically induced decomposition of thioazo compounds XC6H4-N2-S-C6H4CH3 and their polymers with X = NO2, COOH, and SO3H were investigated. The formation of carbon-centered XC6H4. and sulfur-centered .S-C6H4Y radicals was confirmed using spin-trap technique. These reactive radicals either abstract hydrogen from CH3CN solvent molecule forming .CH2CN radical or they recombine to cage products XC6H4-S-C6H4CH3 eliminating N2. The decomposition rate of the investigated thioazo compounds is characterized by a formal half-life time of 5 to 10 s.

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Decreased half-life time of plasma von Willebrand factor collagen binding activity in essential thrombocythaemia: normalization after cytoreduction of the increased platelet count

British Journal of Haematology ◽

10.1046/j.1365-2141.1997.4823285.x ◽

1997 ◽

Vol 99 (4) ◽

pp. 832-836 ◽

Cited By ~ 36

Author(s):

Perry J. J Van Genderen ◽

Fransisco J Prins ◽

Irene S. Lucas ◽

Desiree Van De Moesdijk ◽

Huub H. D. M. Van Vliet ◽

...

Keyword(s):

Platelet Count ◽

Von Willebrand Factor ◽

Half Life ◽

Life Time ◽

Binding Activity ◽

Essential Thrombocythaemia ◽

Collagen Binding ◽

Von Willebrand ◽

Willebrand Factor

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Grasses and legumes as cover crop in no-tillage system in northeastern Pará Brazil

Acta Amazonica ◽

10.1590/1809-4392201305364 ◽

2014 ◽

Vol 44 (4) ◽

pp. 411-418 ◽

Cited By ~ 8

Author(s):

Renato Alves Teixeira ◽

Tatiana Gazel Soares ◽

Antonio Rodrigues Fernandes ◽

Anderson Martins de Souza Braz

Keyword(s):

Half Life ◽

Dry Matter ◽

C:N Ratio ◽

Life Time ◽

Dry Matter Production ◽

Agricultural Systems ◽

Climate Conditions ◽

Jack Bean ◽

No Till ◽

Matter Production

Studies to select one or more species of coverage plants adapted to Amazonian soil and climate conditions of the Amazon are a promising strategy for the improvement of environmental quality, establishing no-till agricultural systems, and thereby reducing the impacts of monoculture farming. The aim of this study was to assess the persistence time, half-life time, macronutrient content and accumulation, and C:N ratio of straw coverage in a Ultisol in northeastern Pará. Experimental design was randomized blocks with five treatments and five replicates. Plants were harvested after 105 days, growth and biomass production was quantified. After 84 days, soil coverage was 97, 85, 52, 50, and 15% for signalgrass (Brachiaria brizantha) (syn. Urochloa), dense crowngrass (Panicum purpurascens), jack bean (Canavalia ensiformes), pearl millet (Pennisetum americanum) and sunn hemp (Crotalaria juncea,), respectively. Signalgrass yielded the greatest dry matter production (9,696 kg ha-1). It also had high C:N ratio (38.4), long half-life (86.5 days) and a high persistence in the field. Jack bean also showed high dry matter production (8,950 kg ha-1), but it had low C:N ratio (17.4) and lower half-life time (39 days) than the grasses. These attributes indicate that signalgrass and jack bean have a high potential for use as cover plants in no-till agricultural systems in the State of Pará.

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Treatment of Joint-Bleedings in Hemophiliacs with Antibodies to Factor VIII with High doses of Fraction Feiba.

10.1055/s-0039-1682562 ◽

1977 ◽

Author(s):

Kl. Schimpf ◽

K. Zimmermann ◽

P. Zeltsch

Keyword(s):

Knee Joint ◽

Factor Viii ◽

Half Life ◽

Clinical Effect ◽

Single Injection ◽

Life Time ◽

Joint Effusion ◽

The Third ◽

Inhibitor Level ◽

High Doses

Observations in 3 patients demonstrated, that joint-bleedings can be controlled with high doses of fraction FEIBA alone or in combination with factor (f) VIII on out-patient basis. First patient, inhibitor 5-10 units (u) per ml, suffered from 24 joint-bleedings within 392 days. 2o of them could be stopped by a single injection of 150-200 u of fraction FEIBA per kg bodyweight (bw). A combination of 90 u of FEIBA and 36 u of f VIII per kg bw had the same effect. But after 5 injections of this combination within 6 weeks, the inhibitor level had risen from 10 to 240 u per ml. During further treatment with 180 u of fraction FEIBA without addition of f VIII, the inhibitor fell down with a half life time of 50 days. The clinical effect of fraction FEIBA was not influenced by the elevated antibody level. Two further patients, inhibitors 2-4 and 32 u respectively, obtained combined injections of 50-100 u of FEIBA plus 36-42 u of f VIII. One patient was on a prophylaxis of 3 injections weekly for 193 days. After 57 injections the inhibitor had fallen from 2-4 u to unmeasurable values. The third patient obtained the above mentioned dosis twice a day for treatment of a knee joint effusion. After 1 week the inhibitor was diminished from 32 to 13 u.

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