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In 2005, an outbreak of severe respiratory disease in a mixed poultry flock that was infected with Chlamydophila (C.) psittaci led to dissemination of the infection to at least 100 small poultry farms in 11 districts of Central Germany. At the same time, a total of 24 persons in contact with poultry from one of the flocks reported flu-like symptoms to their physician, thus suggesting zoonotic transmission. Within 3 weeks, seven individuals had to be hospitalized, with three of them requiring intensive care. Analysis of ompA sequences from chlamydial isolates and directly from clinical samples revealed the presence of both genotype A and E/B of C. psittaci at the source of the outbreak and in contact flocks. Genotype A was also detected in the three severely ill patients. The findings of the present study demonstrate the high zoonotic potential of avian chlamydiae. To ensure speedy eradication of psittacosis in poultry flocks and effective treatment of infected humans, fast, sensitive and species-specific detection of the causative agent is essential, as well as close collaboration between regional public health services, attending physicians and the diagnostic laboratories involved.  相似文献   
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Soil profiles under beech, spruce and a grassland have been analysed to study the evolution of natural n-alkanes in pollution-free ecosystems. The soils had all developed on granitic bedrock, at an altitude of 1300–1500 m in the region of Mont-Lozère (southern Massif-Central, France). In contrast to the grassland soil, the two forest soils both possessed a well-developed acidic moder humus-type horizon. This could be subdivided as follows: fresh litter (OL), fragmentation (OF) and humification (OH) layers; two litters, one fresh (OL1) and one old (OL2) could actually be distinguished in the beech forest soil. The n-alkane signature of the parent plants was preserved in the top litter. Immediately underneath, in the OF layer(s) the original n-alkane signatures were progressively but rapidly replaced by a common signature composed of n-C27 and n-C25 with larger proportions of the former than of the latter. These two hydrocarbons were most probably produced in situ by fungi. These results appear to illustrate the action of soil microorganisms which metabolize the inherited n-alkanes and produce new compounds of the same family. Unlike the alkanes and the low molecular weight fatty acids ≤ C20 (which increase greatly in the OL2 layer under beech as a result of intense microbial activity), the heavy fatty acids (> C20) show no significant change in the organic horizon.  相似文献   
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Purpose

The critical shear stress of cohesive and mixed cohesive/non-cohesive sediments is affected by multiple interacting physical, chemical and biological parameters. There are various mathematical approaches in the scientific literature for computing critical shear stress. However, processes that influence sediment stability are still not fully understood, and available formulas differ considerably. These discrepancies in the literature arise from random system behaviour (natural variability of the sediments), different definitions of the critical shear stress, different measurement techniques and different model frameworks (scope of the parameters, undisturbed versus artificial sediment samples). While analytical approaches fail to address the involved uncertainties, fuzzy logic-based models integrate uncertainty and imprecision.

Materials and methods

With this in mind, a data-driven neuro-fuzzy model (ANFIS) was used to determine the critical shear stress based on sediment characteristics such as wet bulk density and grain size distribution. In order to select model predictors systematically, an automated stepwise regression algorithm was applied. The database for this analysis consisted of 447 measurements of the critical shear stress originating from 64 undisturbed sediment samples.

Results and discussion

The study identified clay content as the primarily controlling variable for erosion resistance. Depending on the characteristics of the sampling location, the bulk density was also selected as a model predictor. In comparison to analytical models that are available in the scientific literature, the fuzzy model achieved higher correlation coefficients between measured and predicted data.

Conclusions

The neuro-fuzzy-model includes uncertainties of input variables and their interactions directly. Thus, it provides a reliable method for the prediction of erosion thresholds of cohesive/non-cohesive mixtures. It was also shown that this approach requires fewer measured variables as well as fewer assumptions than the models it was compared to.
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Within the framework of a cooperative research project, turkey health as well as numerous aspects of animal welfare were examined in various intensive commercial farms with varying rearing forms. The present study demonstrates the prevalence of skin injuries concerning living animals as well as carcasses of slaughtered turkeys of both sexes. Although all turkeys were debeaked, prevalences of skin injuries at a value of 12.8% with male turkeys and 13.8% with female turkeys could be found at the age of 16 weeks. Within the scope of medically inspections skin injuries were mainly established in the head region, especially the snood as well as in the region of the back. By means of their clinical picture pecking wounds and scratch injuries could be distinguished. Skin lesion produced primary as a result of scratching the skin surface, could be enlarged by the animal itself or by conspecifics by beak pecking, especially after bleeding, in spite of debeaked upper beak. Injuries in the head region, especially of the snood, could be explained mainly as a result of pecking by conspecifics by reason of their clinical picture and were found mainly in male turkeys. Skin injuries in the region of the back, especially at the coxal tuberosity, were identified primarily as scratch marks. They were found mainly in female turkeys. A statistically significant correlation of the injury prevalence to particular husbandry parameters discussed in the literature as "predisposing" or "limiting" factors (e.g., population density, light regime or offer of employment material) could not be established in this study. At the meat inspection fresh scratching injuries at the chest and the hind legs were diagnosed most often. Especially fresh injuries of the carcass point to a misguided behaviour of the staff concerning animal handling during loading and transport which is not conform to animal welfare.  相似文献   
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