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Tearing of the thoracolumbar dura mater was diagnosed after myelography in three large breed dogs. All three dogs lost the ability to walk suddenly, after a period of vigorous running or struggling. Radiographic changes suggested that the tearing of the dura was associated with intervertebral disc injury in two dogs. These dogs regained the ability to walk after medical treatment. Postmortem findings suggested that the tearing of the dura mater in the third dog was associated with nerve root injury and spinal cord haemorrhage after an episode of violent struggling. 相似文献
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Do intracoelomic telemetry transmitters alter the post‐release behaviour of migratory fish? 
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下载免费PDF全文 Alexander D.M. Wilson Todd A. Hayden Christopher S. Vandergoot Richard T. Kraus John M. Dettmers Steven J. Cooke Charles C. Krueger 《Ecology of Freshwater Fish》2017,26(2):292-300
Electronic tags have become a common tool in fish research, enhancing our understanding of how fish interact with their environment and move among different habitats, for estimating mortality and recording internal physiological states. An often‐untested assumption of electronic tagging studies is that tagged fish are representative of untagged conspecifics and thus show ‘normal’ behaviour (e.g. movement rates, swimming activity, feeding). Here, we use a unique data set for potamadromous walleye (Sander vitreus) in Lake Huron and Lake Erie tributaries to assess whether the lack of appropriate controls in electronic tagging could seriously affect behavioural data. We used fish tagged in previous years and compared their migratory behaviour during the spawning season to fish tagged in a current year at the same location. The objective of the study was to determine whether intracoelomic acoustic tag implantation altered downstream movement of walleye after spawning. Fish tagged in a given season travelled slower downstream from two river spawning sites than fish tagged in previous years. Fish tagged one or two years earlier showed no differences between each other in downstream travel time, in contrast to fish tagged in a given year. Our results support notions that standard collection and intracoelomic tagging procedures can alter short‐term behaviour (i.e. days, weeks, months), and as such, researchers should use caution when interpreting data collected over such time periods. Further, whenever possible, researchers should also explicitly evaluate post‐tagging effects on behaviour as part of their experimental objectives. 相似文献
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Estimation of average Cenozoic sedimentation rates for the Atlantic, Indian, and Pacific oceans indicates global synchronous fluctuations. Paleocene-early Eocene and late Eocene-early Miocene rates are only a fraction of middle Eocene and middle Miocene-Recent rates. These changes must reflect significantly different modes of continental weathering, which may be due to alternate states of atmospheric circulation marked by reduction of global precipitation. 相似文献
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