Estimating duration and intensity of Neoproterozoic snowball glaciations from Ir anomalies

The Neoproterozoic glaciations supposedly ended in a supergreenhouse environment, which led to rapid melting of the ice cover and precipitation of the so-called cap carbonates. If Earth was covered with ice, then extraterrestrial material would have accumulated on and within the ice and precipitated during rapid melting at the end of the glaciation. We found iridium (Ir) anomalies at the base of cap carbonates in three drill cores from the Eastern Congo craton. Our data confirm the presence of extended global Neoproterozoic glaciations and indicate that the duration of the Marinoan glacial episode was at least 3 million, and most likely 12 million, years.     

Effect of orally administered probiotic E. coli strain Nissle 1917 on intestinal mucosal immune cells of healthy young pigs

Several beneficial effects of probiotics have been described in studies using rodent disease models and in human patients; however, the underlying mechanisms remained mostly unclear. Only a few studies focused on the effects of probiotics on the intestinal mucosal immune system. Here, we studied the effect of the probiotic strain E. coli Nissle 1917 (EcN) administered orally to young pigs at two concentrations (10(9) and 10(11)CFU/d for 21 days) on the gut-associated lymphatic tissue. This probiotic strain was shown recently to reduce recurrence of inflammation in ulcerative colitis patients. We quantified the number and distribution of intestinal immune cells (granulocytes, mast cells, CD4+, CD8+, CD25+, IgA+ lymphocytes) and the mucosal mRNA expression of cytokines (IFN-gamma, TNF-alpha, TGF-beta, IL-10) and antimicrobial peptides (PR-39, NK-lysin, prepro-defensin-beta 1, protegrins). The number and distribution of cells were highly different between small intestinal and colon segments in all groups, but were not influenced by EcN, except high dose EcN fed pigs (10(11) CFU/d) showing an increase in mucosal CD8+ cells in the ascending colon. The mRNA analysis revealed no changes associated with EcN feeding. In conclusion, according to our analyses EcN has only minor effects on the distribution of mucosal immune cells in the gut of healthy individuals. The well-established preventive effects of EcN might therefore be relate to other mechanisms than simple modulation of immune cell distribution.     

Impact of agricultural subsidies on biodiversity at the landscape level

Agricultural management is a major factor driving the change of faunal richness in anthropogenic landscapes. Thus, there is an urgent need to develop tools that allow decision-makers to understand better intended and unintended effects of agricultural policy measures on biodiversity. Here we demonstrate the potential of such a tool by combining a socio-economic model with the biodiversity model GEPARD to forecast the response of bird and carabid species richness to two scenarios of agricultural subsidies: (1) subsidies based on production levels and prices and (2) direct income support that is independent of production levels. We focussed on farmland of the Lahn-Dill area, Germany, as an example of European regions with low intensity farming. GEPARD predicts faunal richness and is based on multi-scaled resource-selection functions. Under both scenarios the area of predicted losses in species richness of birds and carabids was larger than the area of predicted gains in species richness. However, the area with predicted losses of avian richness was smaller under the direct income support scenario than under the production-based subsidy scenario, whereas the area with predicted losses of carabid species richness was smaller under the production-based subsidy scenario than under the direct income support. Yet locally, richness gains of up to four species were predicted for carabids under both scenarios. We conclude that the sometimes contrasting and heterogeneous responses of birds and carabids at different localities suggest the need for spatially targeted subsidy schemes. With the help of the GIS-based approach presented in this study, prediction maps on potential changes in local and regional species richness can be easily generated.     

IPM Strategies and Their Dilemmas Including an Introduction to www. eurowheat.org

Information about disease management in winter wheat （Triticum aestiva） in eight European countries was collated and analysed by scientists and extension workers within the European Network for the Durable Exploitation of Crop Protection Strategies （ENDURE）. This included information about specific disease thresholds, decision support systems, host varieties, disease prevalence and pathogen virulence. Major differences in disease prevalence and economic importance were observed. Septoria tritici blotch （Mycosphaerella graminicola） was recognized as the most yield reducing disease in countries with intensive wheat production, but also rust diseases （Puccinia striiformis and Puccinia triticina）, powdery mildew （Blumeria graminis） and Fusarium head blight （Fusarium spp.） were seen as serious disease problems. Examples of current integrated pest management （IPM） strategies in different countries have been reported. Disease management and fungicide use patterns showed major differences, with an average input equivalent to 2.3 full dose rates （TFI） in the UK and a TFI of 0.6 in Denmark. These differences are most likely due to a combination of different cropping systems, climatic differences, disease prevalence, and socio-economic factors. The web based information platform www.eurowheat.org was used for dissemination of information and results including information on control thresholds, cultural practices which can influence disease attack, fungicide efficacy, fungicide resistance, and pathogen virulence, which are all elements supporting 1PM for disease control in wheat. The platform is open to all users. The target groups of EuroWheat information are researchers, advisors, breeders, and similar partners dealing with disease management in wheat.     

Functional conversion between A-type and delayed rectifier K+ channels by membrane lipids

Voltage-gated potassium (Kv) channels control action potential repolarization, interspike membrane potential, and action potential frequency in excitable cells. It is thought that the combinatorial association between distinct alpha and beta subunits determines whether Kv channels function as non-inactivating delayed rectifiers or as rapidly inactivating A-type channels. We show that membrane lipids can convert A-type channels into delayed rectifiers and vice versa. Phosphoinositides remove N-type inactivation from A-type channels by immobilizing the inactivation domains. Conversely, arachidonic acid and its amide anandamide endow delayed rectifiers with rapid voltage-dependent inactivation. The bidirectional control of Kv channel gating by lipids may provide a mechanism for the dynamic regulation of electrical signaling in the nervous system.     

Determination of 28 Elements in Aquatic Moss Fontinalis Antipyretica Hedw. and Water from the Upper Reaches of the River Nysa (CZ,D), by ICP-MS,ICP-OES and AAS

The concentrations of 28 elements in samples of the bryophyte F. antipyretica Hedw collected from various sites on the upper reaches of the River Nysa and its main tributaries were determined. These results were compared with similar analyses of water samples collected at the same sites. So, it was possible to determine the elemental composition of the water both directly and indirectly, using a bioindicator organism. Analyses were carried out using different instrumental techniques (ICP-MS, ICP-OES, AAS), some elements being analysed by both ICP-MS and ICP-OES. Functional regression analysis showed that for some of these elements, namely Al, Ba, Fe, Sr and Ti in moss, and Ba, Ca and Zn in water samples, there was no significant difference (p < 0.05) in the concentrations determined by both techniques. The coefficients of correlation moss/water for each element were calculated, but they were in general low. However the coefficients of correlation between different elements were in general good. Finally, the elemental concentrations in the aquatic moss were also used to assess the level of contamination in the area of study, through the calculation of CF (Contamination Factor) values.     

Effects of meliorative additives on the adsorption and binding forms of heavy metals in a contaminated topsoil from a former sewage farm

In a laboratory study, a heavy metal contaminated topsoil from a former sewage farm in Berlin was amended with different additives: lime, ash/gypsum, bark mulch, brown coal and combinations of these treatments. After 8 weeks of incubation, pH of the lime and ash/gypsum treatments increased to 6.2–6.3 compared to 5.2–5.3 in the control and the other treatments. Organic-C content rose from 42 g/kg in the control to 46–53 g/kg in the organic amendments. In reaction to the pH-increase the water soluble fraction of Cd, Cu and Zn was reduced by roughly 60%, 30% and 80% respectively. Cd- and Zn-binding forms as determined with NH₄-acetate- and EDTA-extracts were not affected by the treatments, while the ash/gypsum-treatment increased EDTA-extractable Pb by 17%. The exchangeable Cu-Fraction (NH₄-acetate extract) was reduced in all treatments to 82–93% of the control values, with the greatest effects in the tree bark amendment. The FREUNDLICH adsorption isotherms also show an increased sorption of heavy metals in the lime and ash/gypsum treatments. Organic amendments alone or in combination with lime had little effect on heavy metal adsorption.     

Zur Parametrisierung der Stickstoff-Mineralisierung in einem Ackerboden unter Feldbedingungen

A functional relationship for the nitrogen mineralization of an arable soil under field conditions In order to characterize the nitrogen mineralization of a poorly drained, loess-derived field soil (Aeric Fragiaqualf, loamy, mesic) a laboratory incubation experiment was carried out. The measured mineralization rate was expressed as a function of soil temperature and soil water content. At the same time, a field incubation experiment with buried soil samples (so-called Runge samples) was conducted. It was found that the laboratory incubation method overestimated the mineralization rate as compared with the field method. Accordingly, the laboratory data were adjusted. Additionally, it was found that management practices (fertilizer application, harvest, soil cultivation) influenced the course and the extent of the nitrogen mineralization.     

Einige Bemerkungen zur Bestimmung der Wasserleitfähigkeit mit der Bohrlochmethode

Some remarks concerning the determination of the hydraulic conductivity with the auger hole method Values of hydraulic conductivity, achieved with the auger hole method, may depend on the calculation procedure that is used. In this paper, values obtained with the method of Ernst (1950) are compared with such of Boast and Kirkham (1971). It is found, that differences of 25 percent and more may occur. It is concluded that care should be taken when conductivities are calculated from auger hole measurements. The method of Boast and Kirkham (1971) appears to be superior.