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Ragan LC 《Journal of veterinary medical education》2007,34(3):232-237
Distance education (DE) continues to grow as an effective means of education that complements more traditional education modes. Each, to be effective, requires of the instructor a detailed understanding of what creates optimal learning by participants. Because DE is a newer mode, the roles and functions that faculty must play to make it effective have been subject to more scrutiny. Many principles are common to both modes; however, there are some unique aspects of each that faculty of such courses must appreciate. 相似文献
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This report describes the diagnosis of a fracture of the greater tubercle of the humerus and successful repair with 2 cancellous bone screws in a 420 kg adolescent horse. 相似文献
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Ragan BG Nelson AJ Foreman JH Bell GW Iwamoto GA 《American journal of veterinary research》2004,65(9):1204-1210
OBJECTIVE: To evaluate changes in heart rate (HR) and mean arterial pressure (MAP) as indicators of changes in pressor response for muscle afferents after topical application of menthol (MEN)-based analgesic balm. ANIMALS: 11 decerebrate cats. PROCEDURE: Pressor responses were reflexively evoked by static contraction of hind limb muscles, which are caused by group III and IV afferents. Responses were monitored without interference from anesthesia or effects of higher brain function by the use of decerebrate cats. After obtaining baseline data, MEN analgesic balm (1.9%) was applied to the skin over contracting muscles of 1 hind limb in 6 cats; petrolatum was applied to 5 control cats. Muscle contractions were evoked every 10 minutes, alternating between hind limbs, for 120 minutes. Peak MAP and HR were analyzed. RESULTS: Peak MAP responses evoked by static muscle contraction for the ipsilateral hind limb were significantly attenuated 20 minutes after application, but approached baseline values 40 minutes after application. The pressor response was significantly decreased 20 minutes after application during the last 12 seconds of the stimulus, which was attributed to group IV afferents. There were no significant differences in HR responses. CONCLUSIONS AND CLINICAL RELEVANCE: Application of MEN analgesic balm to the skin over contracting muscles significantly decreased the pressor response to static muscle contractions. This suggests that topical application of MEN has effects on responses evoked from receptors located in muscles. The MEN analgesic balm appeared to attenuate the pressor response 20 minutes after application, but it was a short-term effect. 相似文献
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The Animal and Plant Health Inspection Service (APHIS) brucellosis eradication program in the United States 总被引：1，自引：0，他引：1
Efforts to eradicate brucellosis caused by Brucella abortus in the United States began in 1934 as part of an economic recovery program to reduce the cattle population because of the Great Depression and concurrent severe drought conditions. A number of states saw this as an opportunity to reduce the level of brucellosis, which was the most significant livestock disease problem in the US at the time. In 1934 and 1935, the reactor rate in adult cattle tested was 11.5%. In 1954, the magnitude of the brucellosis problem in the United States in terms of economics to the cattle industry and human health prompted Congress to appropriate funds for a comprehensive national effort to eradicate brucellosis. The brucellosis eradication program was designed as a cooperative effort between the federal government, the states, and livestock producers. As the science and technology of brucellosis has developed over the years through research and experience, the eradication program has been modified many times.
As of 31 December 2000, there were no affected cattle herds in the United States. This was the first time in the history of the brucellosis program that the United States had no known brucellosis affected herds. However, brucellosis has a variable, sometimes quite lengthy incubation period, so it is expected that additional affected herds will be disclosed. It is likely that additional affected herds will be disclosed before brucellosis is finally eradicated from cattle. Animal health officials remain prepared to aggressively pursue any newly disclosed affected herds to eliminate the disease as quickly as possible.
The State-Federal Brucellosis Eradication Program has made tremendous progress since its inception. In an eradication program, it is critically important to recognize that, despite all the tools that are available to eliminate the disease, an effective surveillance system is the critical first step that must be in place in order to be successful. It is imperative, not only to be able to find the disease and eliminate it, but to find it before it spreads to susceptible herds. When brucellosis can be identified, contained, and eliminated before spread occurs, eradication can be achieved. 相似文献
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H A Ragan P L Hackett G E Dagle 《Journal of the American Veterinary Medical Association》1976,169(4):421-425
A 10-year-old, Golden Retriever-type castrated male dog was found to have a hemogram consistent with myelophthisic anemia. Within 30 days the hemogram changed in such a manner that a myeloproliferative disorder was evident. On the basis of hematologic, cytochemical, and cytologic findings, acute myelomonocytic leukemia was diagnosed. 相似文献
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An analytical method for the analysis of tulathromycin, an equilibrating triamilide, in bovine and porcine plasma and lung 总被引：2，自引：0，他引：2
Gáler D Hessong S Beato B Risk J Inskeep P Weerasinghe C Schneider RP Langer C LaPerle J Renouf D Bessire A Español E Rafka R Ragan C Boettner W Murphy T Keller D Benchaoui H Nowakowski MA 《Journal of agricultural and food chemistry》2004,52(8):2179-2191
Tulathromycin is a novel member of the triamilide class of antibiotics that was developed as a safe and effective single-dose treatment of bovine and porcine respiratory disease. An accurate and precise analytical method was developed for the extraction and measurement of tulathromycin in livestock plasma and lung homogenates. Analytes were solid-phase extracted onto a weak cation exchanger after aqueous dilution of samples and addition of heptadeutero-tulathromycin as an internal standard. Following HPLC with a narrow bore C8 column, quantitative detection of tulathromycin was accomplished by monitoring the transition of a doubly charged precursor ion to a singly charged product ion by tandem mass spectrometry using a triple quadrupole mass spectrometer. Procedures were validated for a dynamic range of 0.1 to 25 ng on column. Observed accuracies were between 90 and 110% of nominal and precision (RSD) varying 7% or less. Response and stability experiments showed that deuterated tulathromycin did not parallel the chemical behavior of tulathromycin. Applicability of the method to livestock studies was tested with plasma and lung samples from cattle and swine dosed with tulathromycin at multiple doses. The results demonstrated that the analytical method performed well in a range of sample concentrations spanning over 3 orders of magnitude and provided dose-exposure relationships for cattle and swine. 相似文献
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Allelopathy and exotic plant invasion: from molecules and genes to species interactions 总被引：1，自引：0，他引：1
Bais HP Vepachedu R Gilroy S Callaway RM Vivanco JM 《Science (New York, N.Y.)》2003,301(5638):1377-1380
Here we present evidence that Centaurea maculosa (spotted knapweed), an invasive species in the western United States, displaces native plant species by exuding the phytotoxin (-)-catechin from its roots. Our results show inhibition of native species' growth and germination in field soils at natural concentrations of (-)-catechin. In susceptible species such as Arabidopsis thaliana, the allelochemical triggers a wave of reactive oxygen species (ROS) initiated at the root meristem, which leads to a Ca2+ signaling cascade triggering genome-wide changes in gene expression and, ultimately, death of the root system. Our results support a "novel weapons hypothesis" for invasive success. 相似文献