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21.
J. Schneevoigt M. Bahramsoltani K. Gerlach A. Gericke M. Fersterra W. Brehm J. Seeger 《Anatomia, histologia, embryologia》2014,43(1):64-70
Congenital duplication anomalies occasionally occur in both humans and animals. Although various forms of classification of these conjoined twins exist, each case should be considered as an individual. In the case study presented a Holstein Frisian calf, born alive after 281 days of normal gravidity was investigated by computed tomography (CT) and subsequent dissection. The calf could be classified as a parapagus dicephalus tetrabrachius. It exhibited two heads each of them with a complete cervical spine leading to a complete thoracic and lumbar spine and separate tails. Looking at the point of fusion, the twin was conjoined in the ventrolateral thoracic part of the body. The calf had two thoraces with four forelimbs and two pelvic limbs on a single pelvis. As two heads and thoraces were present, beginning at the oral cavity, two intestinal systems were observable leading to a fusion point at the ascending part of the duodenum been continued caudally as a single system. Within each thorax, two lungs and a heart were present. However, only the heart in the left thorax was normal shape, exhibiting a strong myocardium and increased size. In contrast, the heart within the right thorax was considerably smaller, round shaped, and it appeared to be spongy and not fully developed during the foetal period. Commonly, classification of conjoined twins is only based on the appearance of the skeletal system. However, in the case presented, the point of fusion of the skeletal system did not allow conclusions regarding the intestinal or cardiovascular system. 相似文献
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Uncertainty of factors determining runoff and erosion processes as quantified by rainfall simulations 总被引:1,自引:0,他引:1
Rainfall simulations at different scales have been used for understanding the influence of different factors on runoff generation and erosion. They are an accepted method for calibrating and validating physically based rainfall and erosion models. Nevertheless, it is proven that not only the patterns of rainfall are highly variable over space and time. Soil parameters responsible for runoff generation and erosion – e.g. infiltration capacity, soil moisture, aggregate stability – are highly variable, too. The results of more than 100 plot scale rainfall simulations on abandoned fields in different areas of Spain are analysed for identifying and quantifying factors affecting runoff and erosion processes. The variability of superficial runoff and suspended sediment yield is very high within most of the test areas, reaching values up to a runoff coefficient of 1 and yielding 130 g per experiment. Only within the semi-arid areas we can find a significant and high correlation between vegetation cover and sediment yield (and sediment concentration), whereas most of the other investigated surface parameters show no influence on runoff and erosion. 相似文献
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Gr. Heff. Oberförfter Seeger 《European Journal of Forest Research》1870,14(1):63-66
Ohne Zusammenfassung 相似文献
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The microbiological and serological properties of Treponema hyodysenteriae, its mediators of pathogenicity and the morphological changes in infected animals were presented. From these changes and from the disturbances of the intestinal function, the clinical symptoms could be derived. Finally problems of epidemiology, therapy and prophylaxis of swine dysentery were discussed. 相似文献
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