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31.
The water quality in tributaries to Tillamook Bay, Oregon, frequently exceeds standards for fecal coliform bacteria (FCB) and temperature. FCB inputs to the bay have forced periodic closure of the oyster shellfish industry. In addition, impaired water quality may be contributing to reduced salmonid populations in the bay and its tributaries through reduction in the quality of the habitat. Because of these concerns, the Tillamook Bay National Estuary Project (TBNEP) conducted several characterization studies and a long-term water quality monitoring program for the tributary rivers. This paper summarizes data collected to date within these efforts, including storm-based data on FCB and total suspended solids (TSS), and bimonthly data on nutrient concentrations in selected rivers. Monitoring data from 1996 to 2002 are summarized. Results for FCB and TSS are reported by storm, which are classified according to season and precipitation patterns in order to minimize intra-annual variability. There are not indications of large changes in water quality throughout the period of record, but it is too early in the program for trends analysis. Storms that exhibited the highest FCB concentrations tended to be those that occurred during fall and/or those that were preceded by relatively dry conditions and included high rainfall intensity. Implementation of storm-based monitoring and classification of storms according to season effectively reduces the large variability inherent in the FCB monitoring data, thereby facilitating future trends analysis. Continued storm-based monitoring of FCB and TSS, and also continued collection of rainfall and river discharge data, will provide the database that will be needed to determine to what extent on-the-ground remediation actions and best management practices (BMPs) within the Tillamook Basin are having their desired effects.  相似文献   
32.
Despite the increasing recognition of riparian zones as important ecotones that link terrestrial and aquatic ecosystems and of fire as a critical natural disturbance, much remains unknown regarding the influence of fire on stream-riparian ecosystems. To further this understanding, we evaluated the effects of mixed severity wildfire on riparian plant community structure and composition in headwater streams of the Big Creek Watershed of the Frank Church ‘River of No Return’ Wilderness of central Idaho. Five years after a large stand-replacing fire, we conducted riparian vegetation surveys at sixteen reaches across a range of burn types. Non-metric Multidimensional Scaling (NMS) and Multi-Response Permutation Procedure (MRPP) analyses showed an overall shift in community composition and structure between vegetation at unburned and severely burned reaches. Although total plant cover was significantly less at severely burned areas, recovery of the deciduous understory was apparent. Severely burned reaches were characterized by a marked increase in cheatgrass (Bromus tectorum). Reaches that were exposed to low-severity fire were indistinguishable from unburned reaches relative to vegetation community composition and structure, pointing to a possible disturbance threshold that may need to be crossed in order to alter riparian plant communities.  相似文献   
33.
Spinal pain is an important clinical presentation in feline patients, but the underlying causes can often be difficult to elucidate. Dorsal spinous process impingement syndrome ('kissing spine' or in human patients 'Baastrup syndrome') is a significant cause of spinal pain in equine and human patients and radiographically is characterised by a close approximation of adjacent spinous processes with reactive bone sclerosis affecting these spinous processes. In this report we describe the first reported case of dorsal spinous process impingement syndrome in a cat causing spinal pain, and successful surgical management of the syndrome. The affected cat presented at 5 years of age for evaluation of a 7-month history of progressive thoracolumbar pain. Radiographs revealed close approximation of the dorsal spinous processes of the seventh, eighth and ninth thoracic vertebrae (T7, T8 and T9), with associated reactive bone sclerosis. Surgical resection of the T8 dorsal spinous process resulted in complete resolution of the clinical signs with no evidence of recurrence 9 months after surgery.  相似文献   
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SUMMARY Eight-month-old dogs maintained on a high-fat-low-calcium diet were administered a mixture of lead chloride, lead bromide and lead sulphate for prolonged periods at 4 different dose levels. Dogs on high levels of lead showed marked weight loss and gastrointestinal symptoms followed by death. Two dogs on low lead levels developed neurological signs. Radiological investigations showed radiopaque particles in 27 per cent of abdominal radiographs and 'lead lines' in the distal radius of 3 dogs. Highest tissue lead levels were found in bones followed by liver and kidney, brain and spinal cord.  相似文献   
38.
Photoperiod manipulation of insect diapause: a method of pest control?   总被引:3,自引:0,他引:3  
Extension of day length by artificial light in selected field plots in the fall prevented 76 percent of European corn borer [Ostrinia nubilalis (Hübner)] larvae and 70 percent of codling moth [Laspeyresia pomonella (L.)] larvae from entering diapause. Nondiapausing insects cannot survive rigorous winter conditions.  相似文献   
39.
Diabetic complications such as neuropathy, retinopathy, and renal and cardiovascular disease continue to pose major health risks for diabetic patients. Consequently, much effort has focused on approaches that could replace conventional insulin therapy and provide more precise regulation of blood glucose levels. The biohybrid perfused artificial pancreas was designed to incorporate islet tissue and a selectively permeable membrane that isolates this tissue from the immune system of the recipient. Biohybrid pancreas devices containing canine islet allografts were implanted in ten pancreatectomized dogs requiring 18 to 32 units of injected insulin daily. These implants resulted in good control of fasting glucose levels in six of these animals without further exogenous insulin for periods of up to 5 months.  相似文献   
40.
Recent observations of the 1.35-centimeter line emission of water vapor from galactic sources show short-term variability in the spectra of several sources. Two additional sources, Cygnus 1 and NGC 6334N, have been observed, and the spectra of W49 and VY Canis Majoris were measured over a wider range of radial velocity.  相似文献   
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