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A 2-year-old Standardbred gelding was referred for a mass on the palmaromedial right front pastern which was accompanied by progressively worsening lameness. The mass was firm to palpation and covered by normal skin. Ultrasonographically, a smooth encapsulated mass was present, medial to the flexor tendons and palmar to the neurovascular bundle. Because of a poor prognosis for future athletic performance without surgical or chemotherapeutic intervention and economic constraints preventing further diagnostics and treatment, the horse was euthanised. Post-mortem magnetic resonance imaging, histopathology and immunohistochemistry revealed the mass to be a perivascular wall tumour, the first record of such a neoplasia in the horse. 相似文献
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Schmitz JA Vogt RJ Rupp GP Brodersen BW Abel JM Wohlers AR Marx DB 《Journal of veterinary medical education》2007,34(3):340-349
Nebraska veterinary practitioners were surveyed to collect data about background characteristics and other factors related to veterinarians' decision to include or not include food animals in their practices and to practice in rural versus urban communities. Background characteristics that were significantly (p < or = 0.05) associated with choosing food-animal practice included growing up on a working farm or ranch; having parents who owned livestock; growing up in a town with a population of less than 10,000; majoring in animal science at university; being male; and having a primary interest, at the time of entering veterinary college, in food animal-exclusive or mixed-animal veterinary practice. The primary factor for choosing the community in which to practice was rural/urban lifestyle for rural veterinarians, while this factor was second for urban veterinarians. For all groups of veterinarians, the primary consideration in selecting their current practice was the species orientation of the practice. The primary reason for not choosing food-animal practice was better working conditions and lifestyle in companion-animal practice, followed by greater interest elsewhere. 相似文献
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Impact of Endocrine‐Disrupting Chemicals on Reproductive Function in Zebrafish (Danio rerio) 下载免费PDF全文
The prevalence of endocrine‐disrupting chemicals (EDCs) in the aquatic environment has been associated with the wide detection of alterations in the development and physiology of vertebrates. Zebrafish, as a model species, has been extensively used in toxicological research. In this review, we focus on recent published evidence of the harmful effects of EDCs on reproductive function in zebrafish, including skewed sex ratio, immature gonads, diminished sexual behaviour, decreased sperm count, reduced spawning and fertilization. These impairments mostly result from disruption to sex‐steroid hormones induced by endocrine disruptors. We also discuss other effects of exposure to EDCs. In EDC exposure research, despite incomplete assessments of altered gonad histopathology and sexual behaviour, these present potential effective biomarkers or pathways for evaluating the reproductive function in zebrafish on EDC exposure. To date, the pernicious effects of some EDCs on the reproductive performance in laboratory zebrafish are well understood; however, similar alterations remain for further determination in wild‐type fish and more kinds of EDCs. More studies should be performed under established scientific regulatory criteria to investigate the impact of EDCs on reproduction in zebrafish. Moreover, further research is required to explain the definite mechanism of sexual differentiation, which helps in understanding the shift of sexual phenotype with EDC exposure. 相似文献
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An investigation of sheep flocks in the main sheep raising areas of New South Wales showed that the itchmite Psorergates ovis was frequently associated with fleece derangement. In 26 of the 41 flocks examined, P. ovis was the only ectoparasite detected. P. ovis and the sheep body louse Damalinia ovis, were found in 5 flocks. No external parasites were found on sheep examined from the 10 remaining flocks. The type of fleece derangement most frequently recorded was rubbing which in some cases was combined with areas of chewed fleece. Among flocks, there were positive relations between the prevalence of fleece derangement and prevalence of itchmite or scurf and between itchmite count and mean scurf score. Within flocks, itchmite infested sheep or sheep with scurf had higher prevalences of fleece derangement than sheep on which no mites or no scurf were found. Itchmite infested sheep had a higher prevalence of scurf than those with no detectable mite infestation. There were no significant differences in itchmite populations or fleece derangement between untreated flocks and flocks treated with synthetic pyrethroids, organophosphates or arsenic and rotenone. 相似文献
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Chlamydiosis in workers at a duck farm and processing plant 总被引:4,自引:0,他引:4
DG HINTON A. SHIPLEY† JW GALVIN‡ JT HARKIN‡ RA BRUNTON† 《Australian veterinary journal》1993,70(5):174-176
SUMMARY An outbreak of chlamydiosis was Investigated in workers at a duck farm and processing plant during winter 1989. Chlamydia psittaci was isolated from ducks, but there was little evidence of clinical chlamydiosis in the ducks. Serological tests showed that 76% of workers had been exposed to Infection, 12% recently, 16% had not been exposed and 8% had inconclusive test results. There was a strong association (P < 0.05) between years of employment and exposure to Infection. Infection appeared to be contracted during the first year of employment. Measures were Implemented to reduce shed contamination and control rodents and wild birds. At the same time, ducks were medicated, the processing plant was modified, work practices were altered and workers were advised about chlamydiosis to reduce the risk of human infection. 相似文献
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Films of silicon dioxide (SiO2) were deposited at room temperature by means of catalyzed binary reaction sequence chemistry. The binary reaction SiCl4 + 2H2O --> SiO2 + 4HCl was separated into SiCl4 and H2O half-reactions, and the half-reactions were then performed in an ABAB ellipsis sequence and catalyzed with pyridine. The pyridine catalyst lowered the deposition temperature from >600 to 300 kelvin and reduced the reactant flux required for complete reactions from approximately 10(9) to approximately 10(4) Langmuirs. Growth rates of approximately 2.1 angstroms per AB reaction cycle were obtained at room temperature for reactant pressures of 15 millitorr and 60-second exposure times with 200 millitorr of pyridine. This catalytic technique may be general and should facilitate the chemical vapor deposition of other oxide and nitride materials. 相似文献
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Diamonds with delta(13)C values of -2 per mil and less than 50 parts per million (by mass) nitrogen have been isolated from the Abee enstatite chondrite by the same procedure used for concentrating Cdelta, the putative interstellar diamond found ubiquitously in primitive meteorites and characterized by delta(13)C values of -32 to -38 per mil, nitrogen concentrations of 2,000 to 12,500 parts per million, and delta(15)N values of -340 per mil. Because the Abee diamonds have typical solar system isotopic compositions for carbon, nitrogen, and xenon, they are presumably nebular in origin rather than presolar. Their discovery in an unshocked meteorite eliminates the possibility of origins normally invoked to account for diamonds in ureilites and iron meteorites and suggests a low-pressure synthesis. The diamond crystals are approximately 100 nanometers in size, are of an unusual lath shape, and represent approximately 100 parts per million of Abee by mass. 相似文献