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排序方式: 共有1146条查询结果,搜索用时 15 毫秒
51.
Cohen ND Berry SM Peloso JG Mundy GD Howard IC 《Journal of the American Veterinary Medical Association》2000,216(8):1273-1278
OBJECTIVE: To determine the association between high-speed exercise and risk of injury while racing among Thoroughbreds in Kentucky. DESIGN: Matched case-control study. ANIMALS: 206 Thoroughbreds that sustained a musculoskeletal injury while racing and 412 Thoroughbreds that were not injured during the same races. PROCEDURE: Data regarding official timed workouts and races and the Beyer's numbers for the 3 races before the race during which injury occurred were extracted from past performance charts and compared between injured horses and control horses. RESULTS: For injured horses, cumulative distance of high-speed exercise during the 1- and 2-month periods prior to the race in which injury occurred was significantly less than that of control horses; for either period, a difference of 10 furlongs was associated with approximately 2-fold greater risk of injury. Beyer's numbers were significantly higher for injured horses than for control horses. These effects remained significant after adjusting for age and results of prerace physical inspection. CONCLUSIONS AND CLINICAL RELEVANCE: In Kentucky, injured horses had significantly less cumulative high-speed exercise than did control horses during the 1- and 2-month periods prior to the race in which injury occurred. These results differ from those observed in California. The association of injury with cumulative high-speed exercise appears to vary among regions in the United States. 相似文献
52.
Smith KE Wall R Howard JJ Strong L Marchiondo AA Jeannin P 《Veterinary parasitology》2000,88(3-4):261-268
The insecticidal effects of the phenylpyrazole, fipronil, and a pyrethroid, beta-cyfluthrin, on larvae of the blowfly Lucilia sericata were determined in laboratory assays. When first stage larvae of L. sericata were reared on homogenized pig liver which had been treated with known amounts of test compounds, both fipronil and beta-cyfluthrin induced significant levels of mortality compared to acetone and water controls. However, fipronil was approximately 10 times more toxic than beta-cyfluthrin to L. sericata larvae following ingestion. Beta-cyfluthrin had little effect on mortality until concentrations of approximately 0.5 ppm were reached. In contrast, fipronil effected L. sericata mortality at a concentration of 0.05 ppm and 100% mortality was reached by 0.5 ppm. The lethal concentration (LC50) value for beta-cyfluthrin was 1.56 ppm as compared to 0.14 ppm for fipronil. Following contact of first and third stage larvae with cloth impregnated with known amounts of test compound, the mortality profiles of fipronil and beta-cyfluthrin were similar. At short contact times, the LC50 values for fipronil were lower than those for beta-cyfluthrin. However, at the highest contact time evaluated for the first stage larvae, 300 s, there was a reversal in this trend. The results suggest that the phenylpyrazole fipronil may represent a new potential insecticide for development against blowfly strike of sheep. 相似文献
53.
Townsend KM Hanh TX O'Boyle D Wilkie I Phan TT Wijewardana TG Trung NT Frost AJ 《Veterinary microbiology》2000,72(1-2):69-78
A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the abattoirs in Can tho and Tien giang provinces of Southern Vietnam. The presence of Pasteurella multocida in these samples was detected by the combination of direct cultivation and isolation, mouse inoculation and the polymerase chain reaction (PM-PCR). P. multocida was detected in 16 samples by PCR, with 17 strains ultimately isolated. All samples were negative for serogroup B by HSB-PCR and conventional serotyping, with isolates identified as A:3, D:1 or D:3. In addition, all samples were determined to be negative for the P. multocida toxin (PMT). Characterisation of isolated P. multocida by REP-PCR and biotyping revealed nine distinct REP profiles and seven biotypes among the 17 isolates. Some correlation was seen with P. multocida isolated from a previous Australian outbreak of acute swine pasteurellosis, and those isolated from fowl cholera outbreaks in Vietnamese poultry. 相似文献
54.
Regional land-cover change affects biodiversity, hydrology, and biogeochemical cycles at local, watershed, and landscape scales.
Developing countries are experiencing rapid land cover change, but assessment is often restricted by limited financial resources,
accessibility, and historical data. The assessment of regional land cover patterns is often the first step in developing conservation
and management plans. This study used remotely sensed land cover and topographic data (Landsat and Shuttle Radar Topography
Mission), supervised classification techniques, and spectral mixture analysis to characterize current landscape patterns and
quantify land cover change from 1985 to 2003 in the Altiplano (2535–4671 m) and Intermediate Valley (Mountain) (1491–4623 m)
physiographic zones in the Southeastern Bolivian Andes. Current land cover was mapped into six classes with an overall accuracy
of 88% using traditional classification techniques and limited field data. The land cover change analysis showed that extensive
deforestation, desertification, and agricultural expansion at a regional scale occurred in the last 20 years (17.3% of the
Mountain Zone and 7.2% of the Altiplano). Spectral mixture analysis (SMA) indicated that communal rangeland degradation has
also occurred, with increases in soil and non-photosynthetic vegetation fractions in most cover classes. SMA also identified
local areas with intensive management activities that are changing differently from the overall region (e.g., localized areas
of increased green vegetation). This indicates that actions of local communities, governments, and environmental managers
can moderate the potentially severe future changes implied by the results of this study. 相似文献
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57.
Assays of [14C]leucine incorporation were used to measure effects of herbicides on suspensioncultured heterotrophic Solanum nigrum cells. Most herbicidal vs. nonherbicidal chemicals in a set of 47 compounds could be distinguished from each other based on their extent of inhibition of leucine incorporation by S. nigrum cells. Herbicides which failed to inhibit leucine incorporation were photosynthetic inhibitors. Both phytotoxic and nonphytotoxic thiocarbamate analogs (as determined by whole-plant studies) tended to inhibit leucine incorporation. It was concluded that the leucine incorporation screen could detect a majority of compounds tested which are herbicidal, and that it may also be useful to detect compounds which have cellular toxicity which is not observed in the whole plant. 相似文献
58.
59.
E. Combs T. Beachler J. R. Troy A. Olds-Sanchez J. M. Howard A. Fales-Williams M. Yaeger D. M. Tatarniuk 《Equine Veterinary Education》2022,34(8):e318-e322
A 15-year-old Paint mare (Case 1) and a 15-year-old Arabian mare (Case 2) were presented for aggressive and undesired behaviour. Reproductive evaluation revealed, initially, an enlarged ovary with a smaller/normal sized contralateral ovary in each case. Granulosa cell tumour (GCT) panel testing revealed elevated inhibin B in both cases and elevated anti-Mullerian hormone (AMH) levels only in Case 1 determined from currently established reference ranges. Based on a presumptive diagnosis of GCT, bilateral standing ovariectomy was elected for both mares. In each case neoplastic tissue consistent with luteoma was detected only on histological examination in the smaller/normal sized left ovary; the right ovary appearing normal. Long-term follow-up was performed 1 year and 5 years post-operatively by telephone. The owners were satisfied with the outcome and each patient demonstrated resolution of aggressive stallion-like behaviour. Each case returned to the owners' intended use. In conclusion, luteoma should be considered as a differential diagnosis for ovarian neoplasms in horses related to behavioural abnormalities, even in normal-sized ovaries. 相似文献
60.