性控奶山羊精液X和Y精子分离比例检测方法的建立

旨在建立可以定量计算奶山羊精液中X、Y精子数量的双重TaqMan荧光定量PCR方法,用以检测经过分离的奶山羊精液X和Y精子的数量和比例,为性控技术的开发和生产应用提供技术支撑。本研究选择X、Y染色体中特异基因F9及ZFY片段设计引物,建立标准曲线,优化荧光定量PCR反应体系和条件。通过对阳性标准品梯度稀释以及对60支已知纯度的性控精液进行测定（3次重复）来检验方法的敏感性和可靠性。结果显示,所建立的双重TaqMan荧光定量PCR方法特异性和重复性好,X和Y精子检测灵敏性分别为47和51 copies·μL^-1;利用该方法对商品化的奶山羊性控冷冻精液中X和Y精子的数量和比例进行计算,其结果与销售公司提供的X和Y精子的纯度无显著差异（P>0.05）,表明该方法结果可靠。本研究建立的计算奶山羊X、Y精子数量的双重TaqMan荧光定量PCR方法特异性和重复性好,灵敏度高,结果可靠,为计算奶山羊精液分离后X、Y精子数量及比例提供了快速可靠的方法。     

Variations in Seroprevalence and Host Factors for Bovine Anaplasmosis in Illinois

Hungerford, L.L. and Smith, R.D., 1997. Variations in seroprevalence and host factors for bovine anaplasmosis in Illinois. Veterinary Research Communications, 21 (1), 9-18.The modified card agglutination test (MCAT) was used to detect antibodies to Anaplasma marginale in 4994 samples collected from market cattle through the Brucellosis Eradication Program in Illinois. The MCAT reactor rate in the sample was 6.4%. The statewide prevalence estimate increased to between 7.1% and 10.7% when corrected for sampling distribution and test sensitivity and specificity. While the sample reactor rate measures the proportion of infected cattle moving through the market system and into new herds, consideration of the sampling proportions and test characteristics is important when estimating the overall prevalence. Cows were found to be at decreased risk relative to male cattle in lower-prevalence areas, but the risk was similar in higher-prevalence areas. In both higher- and lower-prevalence areas, the risk for seropositivity increased from 1 year of age onwards, but the rate of increase with age was greater in the higher-prevalence areas. Calves, however, had higher seroprevalence levels than 1-2-year-old animals. The risk was highest for Angus and Angus-Hereford cross cattle, while dairy cattle showed a decreased risk in the whole sample, but not when the analyses were stratified by prevalence level. There was a higher concentration of dairy cattle in areas with lower prevalence levels.     

Personal and family backgrounds of first-year veterinary science students at The University of Queensland

Objective To provide information on changes in the social and educational backgrounds of veterinary students over a 10 year period in an effort to determine the extent to which they are representative of the community.
Methods Questionnaires were completed by first-year veterinary students at The University of Queensland in 1985 and 1986 (152 students), and 1995 and 1996 (154), and the data were analysed using the SAS System for Windows.
Results The gender ratio of first-year veterinary students was 50:50 (male:female) in 1985 and 1986 but 10 years later it had changed to 38:62. In 1985 and 1986 77% had come directly from school, with 43% of the total coming from government schools, 17% from Catholic schools and 34% from other private (Independent) schools. A decade later the percentage coming directly from school had decreased to 40%, that from Independent schools increased to 45% and that from cities increased from 53% to 64%. The educational backgrounds of parents varied widely though a high percentage had university degrees; mothers had received less formal education than fathers, and the educational attainments of both parents were higher at the beginning than at the end of the study. More than half (57% initially; 67% 10 years later) the fathers were in professional or managerial occupations, and a similar number (50% initially; 48% 10 years later) of mothers were teachers, nurses or clerks. The number of males from country areas decreased from 26 to 16 over this period.
Conclusion These veterinary students differed from the community generally in that progressively more were female, more were from Independent schools, their parents had more formal education and more of their parents were in professional, managerial or clerical occupations.     

Plasma aspartate aminotransferase and creatine kinaseactivities in thoroughbred racehorses in relation to age, sex, exercise and training

In order to investigate the effect of age, sex and month on the response of plasma aspartate aminotransferase(AST) and creatine kinase (CK) to exercise, blood samples were collected once a month between March and September from a group of 40 2- and 3-year-old (2yo and 3yo) thoroughbred racehorses (kept under the same managemental regimen) at rest before exercise (PRE) and at 2 (2H) and 24h (24H) post-exercise. The absolute change in activities between the 2H and PRE samples (2HΔ) and the 24H and PRE samples (24HΔ) was also calculated. Age had a significant effect on all measured and calculated parameters for colts (C), apart from 24HΔ CK but showed no effect in the fillies (F). Sex only had a significant effect in the 3yo in the 2HΔ CK. In the 2yo, significant effects of sex were found for both CK and AST in the PRE, 2H and 24H samples. The effect of month varied according to the classification group with only the 2yoC not showing any significant effect on any parameter. Fillies were, in general, more likely than colts to show greater than a twofold increase in CK activity at 2H post-exercise and the number of animals showing such an increase decreased as the season progressed. Very little change in AST activities occurred with exercise.     

Equine foetal gender determination in mid‐ to late gestational mares: A practical inquiry

In recent years, the interest in equine foetal gender determination (FGD) during gestation increased remarkably. Ultrasonographic FGD can be performed in two different periods during gestation. The earliest examination can take place at a gestational age of 60–70 days, whereby the genital tubercle is used to differentiate between male and female foeti. The time window of the second approach is wider (120–210 days), and there are more characteristics to take into consideration. In this article, the feasibility and accuracy of ultrasonographic FGD in mid‐ to late gestation are evaluated. One hundred twenty‐one mares from different breeds with a pregnancy stage between 120 and 270 days were examined once, using B‐scale ultrasonography (Esaote MyLab™ClassC). None of the mares were sedated nor shaved, and the procedure was completed within 15 min. Diagnosis was firstly based on the gonads. The final judgement was made based on all visible foetal reproductive organs. In three cases with a pregnancy stage beyond 257 days, FGD was not possible. All of the examined mares in which a FGD could be performed gave birth to a healthy foal. In 98% of the examinations (116/118), the diagnosis was correctly made. In both cases of misdiagnosis, only one characteristic was seen during the procedure and wrongly interpreted. Beyond 210 days of pregnancy, the extremities can preclude a good visualization of the inguinal region. In conclusion, equine FGD in mid‐ to late gestation is an accessible and accurate technique, although a good ultrasound device is a prerequisite and experience and expertise is necessary.     

社会性别视角下农村老年女性的养老困境——以山东省为例

从社会性别的视角出发,通过在山东省17地市的农村进行的610份问卷调查,对当代我国农村老年女性在夫妻权力关系、代际关系、社会生活参与等领域存在的社会性别权力关系的不平等进行了探究。结果发现,农村老年女性处于地域、年龄和性别三重弱势地位,这种弱势地位是女性生命历程劣势累积的结果。     

性别控制胚胎玻璃化一步法稀释冷冻保存技术的研究

为了创立在用户庭院就能应用的玻璃化保存性别控制胚胎的冷冻剂稀释处理方法，采用细管内3种不同液体层构成（A、B、C）法，对新鲜分割胚一步法稀释后的存活能力进行了研究；其次用特定细管最小容量冷却法与上述3种不同液体层构成中效果较好的B法对玻璃化冷冻溶解的新鲜分割胚、体外受精分割胚及冷冻溶解的体外受精分割胚进行一步法稀释后的存活能力予以对比。结果，3种不同液体层构成间胚胎的存活能力无显著差异，B法较高；应用特定细管最小容量冷却法在冷冻溶解的新鲜分割胚、体外受精分割胚及冷冻溶解的体外受精分割胚一步法稀释后的存活能力均显著高于B法。结果表明，特定细管最小容量冷却法是更有效的保存方法。     

Lack of Sex-influence on the In Vitro Metabolism of Ivermectin by Hepatic Microsomal Preparations from Cattle

Veterinary Research Communications -     

"粉领”阶层社会存在与自我认同

粉领阶层的出现是中国经济与社会变迁的产物。木文考察了现代中国城市中粉领女性的生活状态、阶层地位与自我认同，认为粉领阶层处于社会结构的中间阶层，其阶层认同正处于建构发展之中，其性别角色观念则介于现代与传统之间。     

子女性别对农民工外地务工决策的影响——基于中国劳动力动态调查数据的经验分析

农村改革使劳动力流动的障碍得以消除,农村劳动力不断向城市流动。外地务工反映了农民工务工地决策中的地点选择,对其研究有助于在微观层面了解农民工流动的倾向及其内在原因。利用2014年和2016年中国劳动力动态调查数据,运用最小二乘法和工具变量回归方法,分析子女性别差异对农民工外地务工的影响。结果表明,外地务工的农民工收入相对更高,同时家中拥有儿子的农民工更可能选择外地务工。第一胎为男孩将显著提高农民工外地务工的概率,从子女所处成长阶段看,当子女处于婴幼儿和接受义务教育阶段时,子女性别对农民工外地务工影响较小;而当子女处于婚配阶段时,生养儿子将显著提高农民工外地务工的可能性;当子女家庭趋于稳定之后,子女性别的影响不再显著。研究表明,男孩偏好观念对子女性别的影响具有协同作用;当子女处于婚配阶段时,助儿购/建房是农民工外地务工的原因之一。因此,提出营造男女平等的社会环境;积极落实与二胎政策相关的配套政策;进一步推进城乡一体化发展等建议。