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31.
An e-mail/telephone survey of all active North American residency training programs in veterinary pathology was conducted in September 2005. The purpose of this survey was to determine current numbers of trainees, their program length and type, and salaries; to compare current numbers to five years earlier; and, finally, to gauge interest in expanding current programs. All 41 training institutions contacted responded to the survey. Briefly, the survey found that there are currently 235 veterinary pathology residents, for a mean of 5.7 residents per training program. The number of residents currently in training programs and the number of applicants for these programs has increased compared to five years earlier. There is widespread interest in further expanding capacity in these programs, and the coalition of the American College of Veterinary Pathologists and the Society of Toxicologic Pathology is a well-known source of possible funding for additional residents. This survey report further documents the numbers of combined residency/PhD programs, average starting salaries for new residents, outside sponsorship effects on pathology training programs, and some of the common concerns regarding veterinary pathology training programs voiced by the respondents. While residency training capacity has expanded in the last five years, and there is widespread desire to further expand these training programs, a shortage of veterinary pathologists for future market needs will need to be addressed by increased funding from as yet unspecified sources. 相似文献
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Anton T. Ibbotson William D. Riley William R.C. Beaumont Alastair C. Cook Mark J. Ives Adrian C. Pinder Luke J. Scott 《Ecology of Freshwater Fish》2013,22(1):73-81
Over 3 years, 32,444 age‐0 group Atlantic salmon (Salmo salar) parr tagged with passive integrated transponder tags throughout the River Frome catchment were assigned to one of three groups, nonmigrants, autumn migrants and spring smolts, depending on the detection and the timing of detection at downstream tag readers (situated 8.6 km above the tidal limit). We examined the effect of density at the time of tagging (n·m?2), distance upstream from the tidal limit (km), fish length (mm), Fulton condition index, habitat type (divided into two types, main river and carrier), days after 1 September that each fish was tagged and year (replication) on the proportions of fish in each of the migration groups. Distance upstream from tidal limit was strongly negatively related to the proportion of autumn migrants and positively related to the proportion of spring smolts. Nonmigrants had a lower average body size than migrants, although there were no differences in the sizes of autumn migrants and spring smolts in September prior to migration. Fish density had no effect on migration strategy. A lower proportion of fish migrated as autumn migrants from the smaller carrier habitats than the main river channel. There is some evidence that those parr destined to become autumn migrants underwent a lower mortality rate during September before tagging than those destined to become spring migrants indicating possible physiological or behavioural differences between these two groups of fish at that time. More research into the factors responsible for initiating the autumn migration is required. 相似文献
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Abstract – The persistent effects of embryonic temperature stress and individual parentage on fry swimming performance were examined in a cross‐fertilisation experiment using sockeye salmon (Oncorhynchus nerka). A fixed‐velocity test of burst swimming was used to assess the endurance capacity and behavioural performance of individual fry from 10 offspring families incubated at 12, 14 or 16 °C to hatch and then reared through yolk absorption and exogenous feeding stages in a common posthatch environment (average 6.9 °C). Fry burst swim time (BST) was influenced by an interaction between incubation temperature and family identity. Average BST was longer for fry from the 12 °C prehatch treatment compared to 14 and 16 °C, although differences were largely attributable to temperature effects on average fry size. Behavioural observations revealed that fish incubated at 16 °C performed more poorly, having a larger proportion of individuals that required stimulation to swim, fatigued more frequently or were classified as ‘nonswimmers’. Within all three incubation temperature treatments, mean BST varied significantly among offspring families, independent of fry mass and length. An interesting relationship was observed within the 16 °C treatment, whereby families with higher survivorship were characterised with lower mean BSTs. Collectively, these findings demonstrate that exposure to high temperatures in early sockeye salmon development can result in persistent, parentally mediated effects on fry performance. As such, these results provide important insight into how elevated temperature events during egg incubation may affect early life history selection processes and survival in stages beyond when the stressor is experienced. 相似文献
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The mechanisms responsible for > 6000-fold permethrin resistance in a pyrethroid-selected strain of house fly, Learn-PyR, were investigated. Through electrophysiological, in vitro metabolism, in vivo penetration and synergism studies it was demonstrated that the resistance mechanisms consisted of enhanced metabolic detoxification via the mixed-function oxidase (MFO) system, target-site insensitivity and decreased cuticular penetration. The major resistance mechanism was the MFO-mediated detoxification. The elevated MFO activity was correlated with higher levels of cytochrome P-450, cytochrome b5 and NADPH-cytochrome c reductase activity. The kinetics of the latter showed similar Km but greater Vmax values in the Learn-PyR than in the susceptible strain, suggesting that the elevated activity was due to an altered amount, but not an altered form, of the enzyme. The Learn-PyR strain showed widely varying levels of resistance to the pyrethroids tested. Comparison of the pyrethroid structures with the resistance ratios revealed that resistance was highest in the presence of an unsubstituted phenoxybenzyl alcohol moiety. Substitution or certain modifications of the alcohol moiety reduced the level of resistance. Structure of the acid moiety or the presence or absence of an a-CN group did not affect the resistance level. These results are discussed with reference to the resistance mechanisms present. 相似文献
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Walker MC Hill RC Guilford WG Scott KC Jones GL Buergelt CD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(5):463-466
A postprandial ammonia tolerance test (PPATT) was performed on normal dogs and dogs with signs that suggested they may have liver disease. All dogs underwent transcolonic scintigraphy, liver biopsy, or both and were assigned to extrahepatic disease, primary hepatocellular, and congenital portosystemic vascular anomalies (PSVA) groups. Each dog was fed a chicken and rice diet providing 25% of its estimated daily metabolizable energy requirement (MER) as an ammonia challenge. This is practical in patients with liver disease because ammonium chloride administration often causes vomiting or ammonia toxicity. Venous ammonia concentrations were measured before feeding and every 2 hours after feeding for 8 hours. No difference in mean ammonia concentrations between dogs with extrahepatic disease and control dogs was found. Therefore, the specificity of the PPATT was 100%. Dogs with hepatocellular disease showed no change in mean ammonia concentration at any time point, before or after feeding, but sensitivity was greatest when venous ammonia was measured 6 hours after feeding (sensitivity before feeding, 28%, and after feeding, 36%). Among dogs with congenital PSVA, mean ammonia concentrations were higher than the reference range at all time points before and after feeding, and peak mean ammonia concentration occurred 6 hours after feeding. In this group, the sensitivity of the PPATT was 81% before feeding and 91% 6 hours after feeding. This study demonstrates that the measurement of venous ammonia concentration is a useful test to detect congenital PSVA, and the sensitivity of the test may be improved by sampling 6 hours after feeding. The PPATT has poor sensitivity in detecting primary hepatocellular disease. 相似文献