Suchergebnisse

We present a spatial interaction entropy maximizing and structural dynamics model of settlements from the Middle Bronze (MBA) and Iron Ages (IA) in the Khabur Triangle (KT) region within Syria. The model addresses factors that make locations attractive for trade and settlement, affecting settlement growth and change. We explore why some sites become relatively major settlements, while others diminish in the periods discussed. We assess how political and geographic constraints affect regional settlement transformations, while also accounting for uncertainty in the archaeological data. Model outputs indicate how the MBA settlement pattern contrasts from the IA for the same region when different factors affecting settlement size importance, facility of movement, and exogenous site interactions are studied. The results suggest the importance of political and historical factors in these periods and also demonstrate the value of a quantitative model in explaining emergent settlement size distributions across landscapes affected by different socio-environmental causal elements.

Maduramicin is a coccidiostat authorized as feed additive in the European Union for chickens and turkeys for fattening but not for laying hens, considering the risk of residues in eggs. The unavoidable cross-contamination of non-target feed with coccidiostats is regulated by Commission Directive 2009/8/EC and resulting carry-over in food by Commission Regulation (EC) No. 124/2009. To verify the compliance of the maximum levels for maduramicin in feed (50 ++g/kg) and eggs (2 ++g/kg), the carry-over from feed into eggs was investigated. Diets containing 10, 30, and 50 ++g of maduramicin/kg of feed were fed to laying hens. Feed, egg white, and yolk were analyzed by LC-MS/MS. Maduramicin residues were only detected in in egg yolk. Feeding the 10 ++g/kg maduramicin diet resulted in maduramicin concentrations up to 2.5 ++g/kg in whole eggs, already exceeding the maximum level. A carry-over rate of 8% maduramicin from feed into eggs was calculated.

The use of anabolic substances is prohibited in food-producing animals throughout the European Union. No method is available to reliably detect the misuse of natural hormones in cattle. A method was developed to detect the abuse of testosterone in cattle fattening. Synthesized testosterone is rather depleted in the C-13/C-12 ratio. Hence, the method is based on gas chromatography/combustion/ isotope ratio mass spectrometry (GC/C/IRMS) analysis of urine. To select testosterone metabolites and endogenous reference compounds (ERC), the concentration of urinary steroids of cattle was investigated. Dehydroepiandrosterone and androst-5ene-3 beta, 17 alpha-diol were chosen as ERCs to show enclogenous C-13/C-12 ratios. Etiocholanolone and 5 alpha-androstane-3 beta, 17 alpha-diol were chosen as the most important testosterone metabolites. Other metabolites known from literature like epitestosterone were less promising. In principle, GC/C/IRMS is a nonspecific method because finally carbon dioxide is analyzed. Therefore, a dedicated cleanup procedure for the selected steroids was developed. By means of proposed confidence intervals in the isotopic composition of ERCs and metabolites, the administration of testosterone to cattle could be detected reliably. Differences of up to 11 parts per thousand. on the delta-scale between ERC and testosterone metabolites were found after testosterone administration, whereas enclogenous differences did not exceed 2 parts per thousand