Radon—Ein neuer analytischer Ansatz zur “In-situ-Bestimmung” der Gasleitf?higkeit von B?den

Vorliegende Arbeit beschreibt ein neuartiges Verfahren zur “In-situ-Bestimmung” der Gasleitf?higkeit von B?den. Es bedient sich des natürlich vorkommenden, radioaktiven Edelgases Radon. Hierbei wird in einer Me?kammer, die auf dem Boden aufsitzt, die H?he der Radonexhalation registriert. Sie ist u. a. direkt von der Gasleitf?higkeit des Bodens abh?ngig. Da das Verfahren zerst?rungsfrei arbeitet. er?ffnen sich eine Vielzahl von Applikationsm?glichkeiten, wie z. B. Beobachtungen befahrungsbedingter Strukturver?nderungen w?hrend und nach Holzerntema?nahmen sowie Untersuchungen zur Regeneration strukturell ver?nderter B?den. Dies kann beliebig oft und zu beliebigen Zeitpunkten am identischen Bodenausschnitt geschehen. The paper describes a new analytical tool for the “in situ” measurement of the gas permeability of soils. It uses on the exhalation of the redioactive rare gas radon. A chamber covering a certain surface area on the ground registers the amount of radon exhald. One of the factors, which directly controls the exhalation rate is the gas permeability. As this is a non-destructive method several possibilities for applications arise, as for example observation and analysis of changes in soil structure during and after regular timber harvesting, i.e. such caused by forest machines, as well as investigations about the regeneration of damaged sites. These investigations can be repeated as often as desired, at any time and, moreover, on the identical spot.     

Association mapping and marker development of the candidate genes (1 → 3),(1 → 4)-β-d-Glucan-4-glucanohydrolase and (1 → 4)-β-Xylan-endohydrolase 1 for malting quality in barley

Cell wall degradation is a crucial process within the malting process of barley. Therefore, the haplotype diversity of genes for two cell wall degrading enzymes, (1 → 3),(1 → 4)-β-d-Glucan-4-glucanohydrolase and (1 → 4)-β-Xylan-endohydrolase 1, was investigated and associations to malting quality parameters were performed. The (1 → 3),(1 → 4)-β-d-Glucan-4-glucanohydrolase gene glb2 had two major haplotypes defined by three SNPs and one INDEL, which explained 8.9 and 9.5% of the total variation of malt extract content and viscosity in the spring barley gene pool, respectively. The most significant associations of (1 → 4)-β-Xylan-endohydrolase 1 gene X-1 were found for diastatic power, saccharification VZ45 and soluble nitrogen with 18, 12 and 8% of the total variation explained by SNP3 in the spring barleys. High-throughput markers were developed for both genes which can be used for marker assisted selection.     

Untersuchung zur Anwendbarkeit von Sorptionskoeffizienten für die Simulation der Verlagerung von 2, 4, 5-T und LAS in Böden

Investigations for the use of sorption coefficients for simulation of the transport of 2, 4, 5-T and LAS in soils The use of sorption coefficients for the prediction of the transport of 2, 4, 5-trichlorophenoxy-acetic acid (2, 4, 5-T) and of n-dodecylbenzene-sulfonate (LAS) was investigated for four different soil types with the simulation model EXSOL. Linear equilibrium sorption coefficients of 2, 4, 5-T determined in batch studies are not suited for the prediction of the transport wheras values derived from the retention in soil columns better fit the experimental profiles of 2, 4, 5-T in the field. Sorption coefficients for LAS from batch studies with a soil-solution ration of 1:2 and a shaking period of 4 h gave the best results for prediction of LAS transport in the field.     

Minimally-invasive catheterization of the portal, hepatic and cranial mesenteric veins and the abdominal aorta for quantitative determination of hepatic metabolism in dairy cows

The objective of this study was to establish a minimally-invasive, ultrasound (US)-guided technique for the placement of indwelling catheters into the portal, hepatic, and cranial mesenteric veins as well as the abdominal aorta. Catheters were placed in eight healthy dairy cows on day 1. The patency of catheters was tested daily until day 14 when a necropsy was carried out. On day 6, energy intake and hepatic net output of glucose, removal of lactate, and oxygen were determined in seven cows. Post mortem examination revealed that all implanted catheters were in the intended locations. Loss of patency in one portal vein catheter on day 9 was attributable to a fibrin clot. Significant correlations were found between mean energy intake and mean hepatic plasma flow (r=0.91; P=0.004), hepatic glucose output (r=0.81; P=0.027) and hepatic removal of lactate (r=-0.70; P=0.08) and oxygen (r=-0.77; P=0.039), as well as between hepatic glucose net output and removal of lactate (r=-0.92; P=0.004). Minimally-invasive, US-guided transcutaneous catheter placement into the cranial mesenteric, portal and hepatic veins as well as the technique for catheterization of the abdominal aorta appear to be safe, and suitable for studies of quantitative hepatic metabolism in cattle.     

Fate of sulfadiazine administered to pigs and its quantitative effect on the dynamics of bacterial resistance genes in manure and manured soil

The veterinary antibiotic sulfadiazine (SDZ), labelled by ¹⁴C, was administered to pigs to follow the fate of the drug and its metabolites in manure and manure-amended soil, and to investigate the dynamics of drug effects on resistance genes and bacterial communities. In the manure sampled over 10 days, more than 96% of the drug was found as parent compound or metabolites N-acetyl-SDZ and 4-hydroxy-SDZ. While the manure was stored the concentration of SDZ increased by 42% due to deacetylation of the metabolite N-acetyl-SDZ, whereas the minor metabolite 4-hydroxy-SDZ kept constant. In the soil the extractable amounts of the compounds decreased exponentially to less than 1 mg kg^?1 within 11 days after manure amendment. The abundances of SDZ resistance genes sul1 and sul2 were determined by qPCR relative to 16S rRNA genes in total DNA from manure and manure-amended soil. In manure both genes increased exponentially in copy number during the first 60 days of storage, suggesting preferential growth of resistant populations. However, the abundance of sul1 and sul2 decreased below 10^?5 copies per 16S rRNA gene after 175 days. With manure high amounts of sul1 and sul2 were introduced into the soil which were reduced by more than 10 times within 24 days. Thereafter, sul1 was stably maintained in soil, while sul2 further decreased between day 60 and day 165. A mathematical model was developed that could well explain the time course of sul gene abundance by considering the cost of sul genes, horizontal gene transfer, and selection of the resistant populations in the presence of SDZ. Modelling revealed a selective effect of SDZ on sul2 even at low concentrations down to 0.15 mg kg^?1 soil. Bacterial community profiles of manure and manure-amended soil were distinct, indicating that bacteria introduced with manure do not become prominent in soil. The composition of the bacterial community in manure constantly changed during storage, but mainly during the first 10 days. Profiles of soil bacterial communities revealed only a transient perturbation by manure containing SDZ.     

A Quantum Statistical Approach to Remediation Effect of Humic Substances

Among various remediation factors, dissolved organic matter including humic substances (HS) has substantial effect on environmental contamination significantly changing the contaminant??s degradation, bioavailability, reactivity, and immobilization. However, the effects strongly depend on HS concentrations and their aromaticity index (AI). To understand underlying phenomena of remediation action of HS, which is revealed to occur within a definite interval of HS concentrations in water solution, a quantum statistical approach is supposed. Developing this approach, a model of protons as Fermi particles in humic substances was advanced for the first time and applied to describe transformations of HS molecules, i.e., multipoles into micelle structures, which in turn provide for mediating effects in water. Sufficiently high concentration of micelle granules in water solution exists if the concentration of HS lies within a definite interval. It was demonstrated applying a grand canonical Gibbs distribution method to a statistical ensemble of HS particles. Our approach allows for understanding and quantifying some biological and physiological processes connected with mediating action of HS, as for example the reversible red cell aggregation influenced by HS, adsorption of HS particles by cancer cells, and effect of HS on human resistibility to inflammatory processes of different kinds. Application of our results to water systems may be helpful to optimize waste processing and disposal.     

Comparing validation of four ELISA-systems for detection of Salmonella derby- and Salmonella infantis-infected pigs

The objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs.Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella-specific IgM-, IgA-, and IgG- antibodies. In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs. Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis-infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derby-infected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates.     

Natural Remediation of Surface Water Systems Contaminated with Nuclear Waste via Humic Substances in South Ural

Radiological waste disposal and accidents from radionuclide production over several decades have resulted in widespread radioactive contamination of surface water systems in South Ural. Natural attenuation of radioactive contamination of freshwater can be considered as an alternative to manage radioactive materials released into the environment. A management alternative takes advantage of natural remediation processes, especially the binding of radionuclides and their compounds to water body solids via humic substances. The formation of radionuclide complexes with humic acids removes and converts radionuclides to a less hazardous form and is followed by a decrease in radionuclide bioavailability to freshwater biota, especially fish and benthos. Here, we present an investigation and quantification of natural remediation of highly contaminated surface water systems located in South Ural via humic substances. Based on a large set of experimental data, we state that in the surface water systems, humic acids promote the immobilization of radionuclides and thus decrease their bioavailability for fish in the investigated water bodies. We examine the influence of humic substance on the chemical and biological interactions between radionuclides and the environment that has experienced increasing interest concerning the remedial uses of humic materials.     

Sequence variation in the barley genes encoding sucrose synthase I and sucrose phosphate synthase II,and its association with variation in grain traits and malting quality

Sequence diversity in the two barley (Hordeum vulgare L.) genes encoding sucrose synthase I (SSI) and sucrose phosphate synthase II (SPSII), both of which are involved in sucrose accumulation and grain filling, was studied by partial resequencing of eight reference genotypes and SNP analysis by pyrosequencing in a panel of 94 spring and 96 winter European barley varieties. The resequencing was based on two adjacent SSI fragments of size 880 and 820 bp, and a 2,322 bp SPSII fragment. In the SSI gene, 26 SNPs were present in the larger fragment, and 25 in the smaller one, and 11 of these were exploited to develop high-throughput SNP assays used for haplotype analysis. An association analysis based on either a general or a mixed linear model suggested that the predominant three haplotypes influenced certain components of both kernel and malting quality. However, the level of phenotype/haplotype association shown with the SPSII gene was rather low. SNP variation of SSI was used to map the locus to chromosome 7H.