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21.
Tractor rollovers continue to be one of the most frequent causes of agricultural fatalities. Despite knowledge of rollovers and the efficacy of rollover protective structures (ROPS), few New York farmers have considered installing ROPS on their unprotected tractors. Qualitative interviews conducted with an "at-risk" segment of the New York farming community indicate that there are a number of barriers to safety in general and to retrofitting, in particular. The following themes and categories emerged in relation to safety and risk taking: constant exposures to risk with positive outcomes normalizes risk; the modeling of risk by significant others positions risk as part of a farming identity; and the pressure to reduce costs, save time, and accept risk frames risk-taking as the cost-effective option (especially in regard to retrofitting, which farmers believe is both expensive and time-consuming). Recommendations for researchers planning retrofitting interventions would be to focus safety messages on the risk to significant others or on the financial impact of rollovers, and to provide financial incentives and assistance to farmers considering retrofitting.  相似文献   
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近来,Matthews阐述了用小鼠制备抗血清的优缺点。主要优点是实验所用的自交系小鼠很易大量饲养。缺点是从每只鼠身上只能获得很少量(1毫升或更少)的血浆,而且不能象在兔子身上那样有效地产生抗体。这是用芜菁黄花叶病毒(Turnip yellowmosaic virus)分别免疫鼠、兔进行比较得出的结论。但是应该指出,一只鼠只要用10—100微克病毒免疫就能制备出滴度为1/256  相似文献   
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Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs.  相似文献   
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The article provides hands-on advice and scientific background information regarding the management of the equine acute colic patient. It summarizes essential information on the patient's history, clinical examination, and legal aspects. The scope of the history is based on the clinical appearance of the patient. In horses with violent and barely controllable signs of pain, it is limited to colic-associated information such as onset, course and severity of colic signs, and the last time of defecation, as well as prior therapeutic intervention. In these patients, the clinical examination is focussed primarily on the assessment of cardiovascular parameters, rectal temperature, and the patient's behaviour. The nasogastric intubation is an essential part of the examination of a horse with colic to prevent a gastric rupture due to gastric distension. Transrectal palpation is equally important and should always be performed unless there are important reasons to object to this procedure. In most cases, a thorough patient history and clinical examination of an acute colic patient allows the examining veterinarian to make a tentative diagnosis and a prognostic evaluation. This helps with the decision to start a conservative or a surgical therapy. Due to the existing obligatory documentation requirement and the duty to inform patient owners, it is of utmost importance to promptly document one's findings, therapeutic measures, consultations, and information of the patient owner in written form. This supports further therapy and it can also be of relevance in a potentially resulting lawsuit.  相似文献   
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Whether rising atmospheric carbon dioxide (CO2) concentrations will cause forests to grow faster and store more carbon is an open question. Using free air CO2 release in combination with a canopy crane, we found an immediate and sustained enhancement of carbon flux through 35-meter-tall temperate forest trees when exposed to elevated CO2. However, there was no overall stimulation in stem growth and leaf litter production after 4 years. Photosynthetic capacity was not reduced, leaf chemistry changes were minor, and tree species differed in their responses. Although growing vigorously, these trees did not accrete more biomass carbon in stems in response to elevated CO2, thus challenging projections of growth responses derived from tests with smaller trees.  相似文献   
28.
The classification within Echinococcus granulosus is currently under debate. To assess the reproductive potential between the G1 and G6 strains, an experimental double infection was carried out in a dog. First, two fertile hydatid cysts were collected in Algeria from a cow and a dromedary. They were identified as being G1 and G6 with the markers coxI and nadI. Subsequently, a dog was inoculated with protoscoleces from these two cysts. Sixty days after infection, 85 adult worms were recovered from the intestine of the dog. Then, the two cysts and each of these individual parasites were characterized with the multilocus microsatellite EmsB and compared. For all worms, the scolex and the gravid proglottids, separately analyzed, provided an identical profile: the G1 profile was observed in 70 adults, and the G6 profile in the 15 others. No single worm exhibited a hybrid G1/G6 profile. This result suggests the absence of cross-fertilizing between the two taxa under the given experimental conditions, and so, the presence of a strong cross-reproductive barrier. This observation corroborates with the recent reclassification of G1 and G6 within two distinct species.  相似文献   
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为了更好地管理黍稷资源,分辨其身份以及追溯来源,创建一个高效可行的种质资源鉴定系统十分必要。以山西省内各地77份黍稷资源为材料,用上海生工生物股份有限公司合成上游5’端加FAM (blue)荧光基团标记对77份黍稷资源进行PCR及毛细管电泳。结果发现,仅用5个标记组合(RYW3、RYW6、RYW20、RYW37和RYW40)可区分全部材料。其中,组合RYW6+RYW37可区分60份;组合RYW6+RYW20+RYW37可区分69份;组合RYW6+RYW20+RYW37+RYW40可区分73份;组合RYW3+RYW6+RYW20+RYW37+RYW40可区分全部77份。77份材料在8个位点共检出79个等位变异,每个位点检出平均为9.875个,检测到的有效等位变异(Ne)为2.675 9,Shannon多样性指数(I)为0.991 6,Nei’s基因多样性指数(Nei)为0.426 0,多样性信息含量(PIC)为0.553 3。在此基础上,利用ID analysis 4.0在线条形码生成器将对应字符串生成可扫描的条形码DNA分子身份证;利用二维码在线技术将材料基本信息转化成可扫描的二维码D...  相似文献   
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