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Vishal D. Murthy Luis Gaitero Gabrielle Monteith 《The Canadian veterinary journal. La revue veterinaire canadienne》2014,55(2):169-174
The potential link between degenerative changes seen on magnetic resonance imaging (MRI) in osseous-associated cervical spondylomyelopathy (OA-CSM) and clinical signs has not been explored. Our goal was to retrospectively evaluate MRI findings, while investigating potential correlations between these changes, signalment, and clinical signs. Twenty-six dogs diagnosed with OA-CSM were included in the study. Clinical signs were converted into a Modified Frankel Score (MFS) and MRI findings were assessed and graded. Giant breeds had multiple compressed sites and presented at a younger age than large breeds, suggesting a different underlying pathophysiology. Spinal cord compression, most commonly bilateral, was present in 36.8% of intervertebral spaces. Synovial fluid loss and articular process sclerosis were the most common degenerative changes. Most dogs showed identical MFS scores, and no significant correlations were found between MFS and MRI changes. More detailed functional scales should be used to investigate this in the future. 相似文献
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C.D. Evans R. Harriman D.T. Monteith A. Jenkins 《Water, air, and soil pollution》2001,130(1-4):1541-1546
Acid Neutralising Capacity (ANC), calculated as the difference between base cations and acid anions, is widely used as a measure of freshwater acid status, and an indicator of biological conditions. Unlike pH and alkalinity, ANC is conservative with respect to CO2 degassing and reactions with aluminium or organic species. However, since ANC is calculated as the residual of a large number of individual ion determinations, it is potentially sensitive even to relatively small analytical errors. For the Round Loch of Glenhead, SW Scotland, consistency of ANC estimation has been assessed based on a duplicate set of major ion analyses undertaken at different laboratories over an 11 year period. Results indicate that, while the two sets of individual ion determinations correspond well, correlation between calculated ANC values is poor. Consequently, estimated ANC trends exhibit severe discrepancies between datasets; one indicates substantial recovery, the other no apparent trend. These problems with ANC estimation are believed to be general to acidic waters and are of particular concern for long-term monitoring, where ANC changes may be small and difficult to detect (although nonetheless potentially biologically significant). In these situations, it is possible that a more stable measurement of ANC may be obtainable based on titration alkalinity, DOC and aluminium concentrations. Using this method, a small but highly consistent increase in ANC is observed over the study period, although much of this can be attributed to a shift from mineral to organic acidity, rather than an overall reduction in acidity. 相似文献
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Valiela Ivan Mazzilli Stefano Bowen Jennifer L. Kroeger Kevin D. Cole Marci L. Tomasky Gabrielle Isaji Tatsu 《Water, air, and soil pollution》2004,157(1-4):365-391
ELM is an Estuarine Loading Model that calculates mean annual concentration of dissolved inorganic nitrogen (DIN) available to producers in shallow estuaries by considering how different processes modify pools of nitrogen provided by inputs (streams, groundwater flow, atmospheric deposition, N2 fixation, and regeneration), and losses (burial and denitrification), within components of the estuarine system (bare sediments, seagrass meadows, salt marshes, water column). ELM also considers the effect of flushing rate within an estuary. Its formulation was constrained to minimize demands of data needed to run the model. In spite of simplifications such as the use of loss coefficients instead of functional formulations of processes, and uncertainties in all the terms included in ELM, predictions of mean annual DIN in water were not significantly different than field measurements done in estuaries in Cape Cod, Massachusetts, subject to different rates of nitrogen (N) loading. This verification suggests that, in spite of its simple formulation, ELM captures the functioning of nutrient dynamics within estuaries. ELM may therefore be a reasonable tool for use in basic studies in nutrient dynamics and land/estuary coupling. Because of its simplicity and comprehensiveness in inclusion of components and processes, ELM may also be useful in efforts to manage N loads to estuaries and related management issues. 相似文献
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Since 1988, a network of lakes and streams has been monitored in areas of the UK sensitive to surface water acidification. Analysis of 10 years data has focused on the identification and quantification of time-trends in chemical parameters, to establish whether declines in emission of acidifying pollutants have resulted in recovery of acidified surface waters. A national decline in S deposition in the UK since 1988 has not generally been accompanied by a significant improvement in freshwater chemistry. At the three sites where xSO4 concentrations have declined, NO3 has increased and there has been no increase in pH or alkalinity. Upward trends in pH and alkalinity observed at several other sites are not associated with downward trends in acidic anions. Temporal variation in xSO4, NO3, acidity, DOC and other important meaures of surface water quality can all be linked to decadal-scale variation in climate, and this has important implications for the detection of recovery-related trends. 相似文献
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