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John Cassin was one of the leading American ornithologists of the 19th century. Appointed Honorary Curator of Birds at the Academy of Natural Sciences of Philadelphia in 1842, he built and studied the collections of that institution (although engaged full time in business) until his death in 1869. This book represents perhaps his most important and least well known endeavor.
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Rapid Bioassessment Protocols (RBP) and the Sediment Quality Triad (SQT) were used to evaluate the biological effects of a municipal waste-water treatment facility (WWTF) on a small southern stream. During major storm events, raw sewage from the WWTF is released directly into the stream. The headwaters of the stream also receive non-point surface runoff from urban areas. RBP analyses, which included benthos, fish and habitat evaluations, and SQT, including the benthos (from the RBP), contaminant analyses (metals, organochlorine pesticides, PCBs and PAHs) andl toxicity tests of depositional sediment (exposures of Hyalella azteca to solid-phase sediment and pore water) were conducted at five sites on the stream (two upstream of the WWTF and three downstream). The stream has been channelized throughout its entire length, resulting in high, unstable banks, degraded stream channel, and unstable substratum. RBP analyses indicated that the two stations upstream of the WWTF were degraded due to poor physical habitat quality (unstable benthic substratum and lack of fish habitat). The SQT also showed reduced habitat quality at the two stations above the WWTF, but the cause was attributed to high concentrations of PAHs and metals in the sediments. The increased discharge and stabilized base flow provided by the WWTF improved habitat quality downnstream, although conditions were still impaired due to the habitat alteration. Though the causes of degradation were attributed to different factors (physical habitat vs. contamination), there was close concordance between the RBP and SQT in identifying the degraded sites in this stream. The combination of these two procedures provides a robust examination of environmental quality utilizing the weight of evidence approach.
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Numerous infections and parasitic diseases have been reported for the gray wolf, including more than 10 viral, bacterial, and mycotic disease and more than 70 species of helminths and ectoparasites. However, few studies have documented the role of diseases in population dynamics. Disease can affect wolf populations directly by causing mortality or indirectly by affecting physiological and homeostatic processes, thriftiness, reproduction, behavior, or social structure. In addition, wolves are hosts to diseases that can affect prey species, thus affecting wolf populations indirectly by reducing prey abundance or increasing vulnerability to predation. Diseases such as canine distemper and infectious canine hepatitis are enzootic in wolf populations, whereas rabies occurs in wolves primarily as a result of transmission from other species such as artic and red foxes. Contact between wolves and domestic pets and livestock may affect the composition of diseases in wolves and their effects on wolf populations. Dogs were suspected of introducing lice and canine parovirus to several wolf populations. THe potential for disease to affect wolf populations and other wild and domestic animals should be considered in wolf management plans, particularly in plans for reintroduction of wolves to area within their former range.
Two new species of the Nearctic perlid genus Perlesta, P. durfeei Kondratieff, Zuellig, and Kirchner and P. georgiae Kondratieff, Zuellig, and Lenat are described and illustrated from Virginia and North Carolina, U.S.A., respectively.
[No abstract available]
[No abstract available]
A digital shaded-relief image of the 48 contiguous United States shows the details of large- and small-scale landforms, including several linear trends. The features faithfully reflect tectonism, continental glaciation, fluvial activity, volcanism, and other surface-shaping events and processes. The new map not only depicts topography accurately and in its true complexity, but does so in one synoptic view that provides a regional context for geologic analysis unobscured by clouds, culture, vegetation, or artistic constraints. -Author