Enterogastrone inhibits eating by fasted mice

In mice fasted for 17 hours, administration of enterogastrone purified from hog duodenum reduced the food intake. This effect was greatest during the first 30 minutes, but the cumulative reduction continued for at least 4 hours. Other peptides prepared from hog duodenum or colon, as well as glucagon, secretin, glucose, and bovine serum albumin, were ineffective.     

Utilisation d'anticorps spécifiques d'une fraction obtenue par chromatographie d'exclusion pour une amélioration de la caractérisation sérologique deRhizoctonia solani Kühn AG3

La purification d'un extrait mycélien soluble d'une souche deR. solani AG3 par chromatographie d'exclusion permet de recueillir une fraction antigénique. Une lapine est immunisée par voie intradermique. L'immunsérum titre 0,125 par la technique de double-diffusion en agarose. Différentes techniques sérologiques (immunodiffusion, électrotransfert suivi de révélation des fractions antigéniques, coloration immunoenzymatique du mycélium) sont appliquées à des souches deR. solani AG1, AG2, AG3, AG4, AG5, AG6, AG7, AGBI et deCeratobasidium CAG1, CAG2, CAG3, CAG4 et CAG5. Le sérum se révèle spécifique des souches AG3. A soluble mycelial extract ofR. solani AG3 was purified by size exclusion chromatography. Five peaks were present in the elution profile: the first was well defined and of large volume. It was retained to immunise a female rabbit by intradermic injection. The titre of the antiserum determined by double immuno-diffusion in agarose was 0.125. The antiserum was tested on isolates ofR. solani AG1, AG2, AG3, AG4, AG5, AG6, AG7, AGB1 and ofCeratobasidium CAG1, CAG2, CAG3, CAG4 and CAG5 (Table 1) using three different methods:

Genotypic variability in P use efficiency for symbiotic nitrogen fixation is associated with variation of proton efflux in cowpea rhizosphere

Vigna unguiculata sp., or cowpea, varieties vary in their adaptation to low-P soils. In order to investigate to what extent this variation may be related to P use efficiency and proton efflux by nodulated roots, three genotypes, 26-73, Danila and Melakh, inoculated with Bradyrhizobium sp. Vigna CB756 were grown in hydroaeroponic culture in a glasshouse at two levels of phosphorus supply corresponding to P sufficiency or P deficiency. After 4 weeks, individual symbiotic-plants were transferred to a reference-soil layer in a rhizotron, and harvested after 2 further weeks. Nodule and shoot biomass were less when P was deficient. The effect of P deficiency on biomass production followed the trend Danila > 26-73 > Melakh. Under P deficiency, the proton efflux for the P-efficient genotype 26-73 was 43% and 60% greater than for the P-inefficient Danila in hydroaeroponics and in soil, respectively. This increase in proton efflux was associated with an increase in nodule specific respiration that was 115% greater for Danila than for 26-73. It is concluded that the genotypic variability in P use efficiency for symbiotic nitrogen fixation is associated with a variation in nodulated-root proton efflux and respiration in cowpea rhizosphere, and that these parameters should be measured for more contrasting genotypes in order to test whether they correlate with the adaptation of N₂-dependent legumes to low-P soils.     

Soil organic carbon–stock changes in Flemish grassland soils from 1990 to 2000

Total soil organic‐carbon (SOC) stocks for grassland soils in Flanders (N Belgium) were determined for the Kyoto Protocol reference year 1990 and 2000 in order to investigate whether these soils have been CO₂ sinks or sources during that period. The stocks were calculated by means of detailed SOC datasets, which were available at the community scale for the whole of Flanders. The total SOC stocks for Flemish grassland soils (1 m depth) were estimated at 38 Mt SOC in 1990 and 34 Mt SOC in 2000. The loss of SOC resulted from a decrease in the SOC content of grassland soils (71%) and could also partly (29%) be explained by a decline in grassland area. Significant decreases in %SOC for the 0–6 cm depth layer were found for the 1990s for the coarser‐textured soils with SOC losses ranging between –0.3% and –0.5% over the 10 y period. Specific management practices that disturb the SOC balance such as conversion to temporary grassland and a reduction of animal‐manure application are hypothesized to have contributed to the observed loss of SOC stocks. We furthermore conducted an analysis of uncertainty of the 1990 and 2000 grassland SOC–stocks calculation using Monte Carlo analysis. Probability‐distribution functions were determined for each of the inputs of the SOC‐stock calculation, enabling us to assess the uncertainty on the 1990 and 2000 SOC stocks. The frequency distributions of these simulated stocks both closely approached lognormal distributions, and their 95%‐confidence intervals ranged between 150% and 50% of the calculated mean SOC stock. The standard error on the measured decrease in SOC stocks in Flemish grassland soils during the 1990s was calculated to be 7–8 Tg SOC, which is equivalent to twice this decrease. This clearly shows that large‐scale changes in SOC stocks are uncertainty‐ridden, even when they are based on detailed datasets.     

Anti-inflammatory activity of human IgG4 antibodies by dynamic Fab arm exchange

Antibodies play a central role in immunity by forming an interface with the innate immune system and, typically, mediate proinflammatory activity. We describe a novel posttranslational modification that leads to anti-inflammatory activity of antibodies of immunoglobulin G, isotype 4 (IgG4). IgG4 antibodies are dynamic molecules that exchange Fab arms by swapping a heavy chain and attached light chain (half-molecule) with a heavy-light chain pair from another molecule, which results in bispecific antibodies. Mutagenesis studies revealed that the third constant domain is critical for this activity. The impact of IgG4 Fab arm exchange was confirmed in vivo in a rhesus monkey model with experimental autoimmune myasthenia gravis. IgG4 Fab arm exchange is suggested to be an important biological mechanism that provides the basis for the anti-inflammatory activity attributed to IgG4 antibodies.     

Dynamics of storm-driven suspended sediments in a headwater catchment described by multivariable modeling

Purpose  

Previous research has shown that the rate at which suspended sediment is transported in watercourses depends primarily on discharge (Q) as the first-order control, but additional factors are thought to affect suspended sediment concentrations (SSC) as well. Among these, antecedent hydrological and meteorological conditions (e.g., rainfall depth and intensity, discharge prior to a runoff event and the duration of runoff events) may represent significant transport controlling mechanisms. Univariate models using Q–SSC rating curves often produce large scatter and nonlinearity, because many of the hydrological and biotic processes affecting the dynamics of sediment are non-linear and exhibit threshold behavior. The simulation of such highly non-linear processes is therefore an elusive task requiring consideration of several interrelated controlling variables. The aim of this study was to identify the major hydrological and meteorological controls determining the dynamics of SSC during storm-runoff events and the magnitude of SSC in a headwater catchment in Luxembourg.     

Effects of rumen-protected oil supplementation on finishing grazing beef cattle

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of rumen-protected oil (soybean and palm oil) in supplements for beef cattle during the fattening...