排序方式: 共有44条查询结果,搜索用时 31 毫秒
11.
12.
Severe respiratory disease, associated with seroconversion to bovine respiratory syncitial virus (BRSV), caused the death of two cattle and necessitated antibiotic treatment of 70 calves (rectal temperature of 39.6°C or greater) from a group of 96 (73%) during an 8-day period. Tilmicosin injection resulted in a reduction in median rectal temperature from 40.3°C to 39.2°C and 39.0°C for the first and second days after treatment. The rectal temperature was 39.5°C or lower in 72% (48 of 67) and 96% (64 of 67) of cattle 1 and 2 days after tilmicosin treatment, respectively. Ten cattle were re-treated with tilmicosin 6 to 16 days after the first treatment. Our study demonstrated that bovine respiratory syncytial virus infection could cause severe respiratory disease in a beef herd that had no previous history of BRSV-related disease. Secondary bacterial invasion after BRSV infection was controlled effectively by tilmicosin treatment but repeat antibiotic treatments were occasionally necessary due to bacterial re-infection of the respiratory tract. 相似文献
13.
Jessica M. Price Janet Silbernagel Kristina Nixon Amanda Swearingen Randy Swaty Nicholas Miller 《Landscape Ecology》2016,31(5):1093-1115
Context
Broad-scale land conservation and management often involve applying multiple strategies in a single landscape. However, the potential outcomes of such arrangements remain difficult to evaluate given the interactions of ecosystem dynamics, resource extraction, and natural disturbances. The costs and potential risks of implementing these strategies make robust evaluation critical.Objectives
We used collaborative scenario modeling to compare the potential outcomes of alternative management strategies in the Two Hearted River watershed in Michigan’s Upper Peninsula to answer key questions: Which management strategies best achieve conservation goals of maintaining landscape spatial heterogeneity and conserving mature forests and wetlands? And how does an increase in wildfire and windthrow disturbances influence these outcomes?Methods
Scenarios were modeled using the VDDT/TELSA state-and-transition modeling suite, and resulting land cover maps were analyzed using ArcGIS, FRAGSTATS, and R statistical software.Results
Results indicate that blending conservation strategies, such as single-ownership forest reserves and working forest conservation easements in targeted areas of the landscape, may better achieve these goals than applying a single strategy across the same area. However, strategies that best achieve these conservation goals may increase the sensitivity of the landscape to changes in wildfire and windthrow disturbance regimes.Conclusions
These results inform decision-making about which conservation strategy or combination of strategies to apply in specific locations on the landscape to achieve optimum conservation outcomes, how to best utilize scarce financial resources, and how to reduce the financial and ecological risks associated with the application of innovative strategies in an uncertain future.14.
15.
CR SMITH BG CORNEY MR McGOWAN CS McCLINTOCK W. WARD PJ KETTERER 《Australian veterinary journal》1997,75(11):818-821
Objective To assess the effect of amoxycillin treatment on urinary excretion of leptospires from cattle infected with Leptospira borgpetersenii serovar hardjo .
Design A chemotherapy trial with controls.
Procedure Fourteen heifers serologically negative to L hardjo were inoculated with L hardjo via the conjunctival route and assessed for evidence of infection by serological, fluorescent antibody and microbiological tests. Two injections (48 h apart) of amoxycillin at a dose of 15 mg/kg were administered intramuscularly to seven heifers 6.5 weeks after infection; the remaining heifers acted as untreated controls. Later, these seven control group heifers were treated with a single dose of amoxycillin (15 mg/kg). Samples of urine were collected before and after amoxycillin treatments; kidneys were collected at slaughter, and examined by fluorescent antibody test and microbiological culture.
Results Leptospires were isolated from the urine of 11 of 14 heifers inoculated with L hardjo . After treatment of six of these with two injections of amoxycillin, leptospires were not isolated. Of the controls, four of the five initially leptospiruric heifers continued to shed leptospires; after a single injection of amoxycillin, no leptospires were detected in the kidneys of these four.
Conclusion Amoxycillin may be an acceptable alternative to dihydrostreptomycin sulphate for the treatment of cattle infected with L hardjo . 相似文献
Design A chemotherapy trial with controls.
Procedure Fourteen heifers serologically negative to L hardjo were inoculated with L hardjo via the conjunctival route and assessed for evidence of infection by serological, fluorescent antibody and microbiological tests. Two injections (48 h apart) of amoxycillin at a dose of 15 mg/kg were administered intramuscularly to seven heifers 6.5 weeks after infection; the remaining heifers acted as untreated controls. Later, these seven control group heifers were treated with a single dose of amoxycillin (15 mg/kg). Samples of urine were collected before and after amoxycillin treatments; kidneys were collected at slaughter, and examined by fluorescent antibody test and microbiological culture.
Results Leptospires were isolated from the urine of 11 of 14 heifers inoculated with L hardjo . After treatment of six of these with two injections of amoxycillin, leptospires were not isolated. Of the controls, four of the five initially leptospiruric heifers continued to shed leptospires; after a single injection of amoxycillin, no leptospires were detected in the kidneys of these four.
Conclusion Amoxycillin may be an acceptable alternative to dihydrostreptomycin sulphate for the treatment of cattle infected with L hardjo . 相似文献
16.
17.
Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby 总被引:1,自引:0,他引:1
DK Yeomans J Barriot DW Dunham RW Farquhar JD Giorgini CE Helfrich AS Konopliv JV McAdams JK Miller WM Owen DJ Scheeres SP Synnott BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109
The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter. 相似文献
18.
Community food production in the form of home gardening, community gardening, school gardening, and urban farming continues to increase in popularity in many parts of the world. This interest has led to public and private investment in community food production and increased need for urban agricultural planning as a way to manage growth and prioritize resource allocation. Municipal planning and thoughtful institutional support for the practice will require program evaluation and greater attention to the spatial composition and configuration of this widely dispersed practice. This article explores the results of community-supported landscape socio-ecological research in Madison, WI (USA) to assess the spatial and social dynamics of community food production. Results indicate that community food production resources are unevenly distributed across the study area. Historic community garden placement does appear to be consistent with community prioritization which dictates placing resources in areas with low median household income. However, home garden presence and recent community garden placement both occur in areas of higher than average median household income. Specific focus is placed on how an understanding of landscape placement and pattern has helped inform attempts to meet municipal and regional objectives in addressing urban food insecurity. 相似文献
19.
DJ Leatherman SA Valdez BG Grant JC Cannon 《Journal of Equine Veterinary Science》1999,19(12):776, 778
Protein fractions of cerebral spinal fluid samples were analyzed in an effort to find a reliable, minimally invasive and cost effective method of diagnosing cervical vertebral myelopathy. There were six separate protein fractions analyzed by electrophoresis. In this study we specifically looked for a post beta spike in horses with spinal cord compression. There was no correlation in our study between horses with a post beta spike and CVM as diagnosed by a myelogram. 相似文献
20.