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The mean gastric emptying versus time curve of the small markers on day one was chosen to represent the reference curve for healthy dogs. The lag phase of the small markers on day one was 2.45 ± 2.04 hours, the T
Management of tropical marine environments calls for interdisciplinary studies and innovative methodologies that consider processes occurring over broad spatial scales. We investigated relationships between landscape structure and reef fish assemblage structure in the US Virgin Islands. Measures of landscape structure were transformed into a reduced set of composite indices using principal component analyses (PCA) to synthesize data on the spatial patterning of the landscape structure of the study reefs. However, composite indices (e.g., habitat diversity) were not particularly informative for predicting reef fish assemblage structure. Rather, relationships were interpreted more easily when functional groups of fishes were related to individual habitat features. In particular, multiple reef fish parameters were strongly associated with reef context. Fishes responded to benthic habitat structure at multiple spatial scales, with various groups of fishes each correlated to a unique suite of variables. Accordingly, future experiments should be designed to test functional relationships based on the ecology of the organisms of interest. Our study demonstrates that landscape-scale habitat features influence reef fish communities, illustrating promise in applying a landscape ecology approach to better understand factors that structure coral reef ecosystems. Furthermore, our findings may prove useful in design of spatially-based conservation approaches such as marine protected areas (MPAs), because landscape-scale metrics may serve as proxies for areas with high species diversity and abundance within the coral reef landscape.
相似文献Cox proportional hazards modeling techniques were used to estimate the association of the contract breeding, as well as the effect of other significant predictors, with the hazard of pregnancy. Two separate Cox models were developed and compared: one that only considered fixed covariates and a second that included both fixed and time-varying covariates. Estimates of effects were expressed as the hazard ratio (HR) for pregnancy.
Results of the fixed covariates model indicated that, controlling for breed, herd size, use of ovulation synchronization protocols in the herd, whether somatic cell score exceeded 4.5 prior to pregnancy or censoring, parity, calving season, and maximum test-day milk prior to pregnancy or censoring, the contract breeding program was associated with an increased hazard of pregnancy (HR = 1.315; 95% CI 1.261–1.371). The results of the time-varying covariates model, which controlled for breed, herd size, use of ovulation synchronization protocols, somatic cell score above 4.5, parity, calving season, and testing season also found that the program was associated with an increased hazard of pregnancy (HR = 1.387; 95% CI 1.327–1.451).
The fixed and time-varying covariates models both found similar sets of predictors when analyzing the association of the contract breeding program with hazard of pregnancy. Both models identified a 30% or greater increase in hazard of pregnancy associated with use of the contract breeding program, suggesting that herds subscribing to the program achieved pregnancies in a more timely fashion. 相似文献
Objective: To describe the signalment, month of presentation, common clinical signs, clinicopathologic values, diagnostic tests used, antimicrobial use, and survival status in horses affected with EPE; to evaluate how affected horses sold at public auction as yearlings; and to determine results of fecal polymerase chain reaction (PCR) and serum immunoperoxidase monolayer assay (IPMA) results in age matched, clinically normal herdmates.
Animals: The study group was 57 horses treated for disease associated with L. intracellularis infection between August 2005 and January 2007.
Methods: Retrospective study examined horses exhibiting evidence of infection with L. intracellularis and testing positive for fecal PCR or serum IPMA.
Results: Horses ranged in age from 2 to 8 months with a median age of 6 months, and all were examined between August and January. Ventral edema was present in 81% of horses and hypoalbuminemia occurred in all horses. Only 50% of horses tested positive on both PCR and IPMA. Ninety-three percent of horses survived, and survival was unrelated to antimicrobial administered. Affected horses sold as yearlings an average of 68% less than other yearlings by the same sire. Age matched, clinically normal herdmates also tested positive for L. intracellularis on fecal PCR (6%) and IPMA (33%).
Conclusion: L. intracellularis infection should be considered in young horses with ventral edema and hypoalbuminemia that are examined between August and January. Both fecal PCR and serum IPMA are needed to help determine disease status. Treated animals usually survive, although they do not sell for as high a price at public auction as other yearlings by the same sire. Age matched, clinically normal herdmates also test positive for L. intracellularis on fecal PCR and serum IPMA. 相似文献