利用aroA基因建立鸡传染性鼻炎PCR诊断方法

利用aroA基因设计了1对引物,分别对10株标准副鸡嗜血杆菌(HPG)菌株、14株分离的HPG菌株进行PCR扩增,结果均得到了与预期大小一致的片段,而对10株非HPG菌株和3株病毒进行扩增则无相应片段产生;该PCR能检测出10个菌细胞.与常规PCR方法相比,aroA-PCR的敏感性更高.     

旋毛虫5日龄成虫期特异性基因片段的克隆及鉴定

利用差减抑制杂交(SSH)技术,以旋毛虫5日龄成虫的cDNA为试验方(tester),以肌幼虫+3日龄成虫的cDNA为驱动方(driver),制备5日龄成虫差减cDNA,并与pT-Adv载体相连接,转入大肠埃希氏菌TOP 10F.以试验方的差减cDNA PCR产物+未差减cDNA为试验方探针,以驱动方的差减cDNA PCR产物+未差减cDNA为驱动方探针,对5日龄成虫差减cDNA克隆进行初步筛选,对筛选到的阳性克隆进一步用southern blot进行鉴定,并对其测序,进行序列分析.结果表明,获得1个大小为464 bp的旋毛虫5日龄成虫期特异性cDNA片段,经BLAST软件分析表明,该序列是1个未见报道的旋毛虫基因序列片段,可能编码1种表皮胶原蛋白.这为旋毛虫5日龄成虫期特异性基因全长序列的钓取、分析及鉴定奠定了基础.     

20世纪初俄国革命历史编纂学的基本问题

二月革命是俄国民主发展的历史分界线.但半年之后,就发生了十月革命,民主体系瓦解,20世纪俄国和世界历史的发展方向也就此根本改变.俄国第一个共和体制垮台的主要原因是,在等级社会、资格选举体系和群众政党缺失的条件下,建立经典议会制的思想却在革命领导人的意识中占居统治地位.二月革命虽然没有完成,但它的历史意义非常重大:由它宣告的自由主义改革纲领在后苏联时期开始得到实施.二月民主体系破产的经验,对20世纪末宪法危机的解决也产生了影响.在廓清会导致民主改革间断的社会因素时,重要的是要及时地用详细制订的解决冲突的方法与这些因素相抗衡.     

历史主义的解释学问题

在19世纪,除了浪漫主义的解释学外,还有历史主义的解释学。它们之间的一个重要的联结点是解释学循环。除此之外,二者的密切关系在其师承和道统方面。布克、德罗伊森和狄尔泰三人的思想代表了西方19世纪下半叶解释学的一个重要的特点,那就是突出与人文科学的联系,这是以历史意识的逐步确立为中介的,但是他们,尤其是德罗伊森和狄尔泰最终都没能摆脱历史的局限。     

基于六边形理论的学生领导力发展观

在充满复杂性的时代,关注领导力是有必要的。在以快速变化、高度工业化为特征的第三个千年中,通讯与信息技术时代与数字世界需要能够推进世界革新的领导人。由于教育系统已经将培养政治领导、社会、经济、文化和科技等领域的领导人涵盖其中,而这些领导人将把握社会方向,促进世界发展。因此,学生领导力成为现阶段的重要学科。学生领导力发展六边形理论,内涵丰富,从个人、集体和社会各个角度出发,建立系统性观点,旨在进一步推进学生领导力发展理论。     

Adolescent Daughters’ Romantic Competence: The Role of Divorce,Quality of Parenting,and Maternal Romantic History

This study examined the links between parental divorce, quality of maternal parenting, spousal relationships and middle adolescent romantic competence in 80 mother-adolescent daughter pairs (40 divorced). Mothers were asked to describe their attitudes and behaviors with regard to their daughters’ romantic behavior. In addition, mothers were interviewed about their own romantic experiences when they were at the age of their daughters. Adolescent girls (mean age = 16.98 years; range 16–18) were administered a comprehensive interview about romantic competence. Findings indicated that adolescent girls from divorced families showed lower levels of romantic competence, which were expressed in their behavior, attitudes toward relationships and skill in handling those relationships. Divorce was found to have had an adverse effect on girls’ romantic competence, whereas continued adaptive parenting and spousal relationships alleviated the effect of divorce. Mothers’ coherent representation of their own adolescent romantic experiences also alleviated the effect of divorce on daughters’ romantic behavior. Results show the important role of family relationships in fostering romantic competence among adolescent girls.     

Microcontextual Characteristics of Peer Victimization Experiences and Adolescents’ Daily Well-Being

Microcontextual factors (i.e., contextual characteristics of the specific victimization incident) may help to explain the association between adolescents’ daily peer victimization experiences and well-being. In the present study, daily report methodology was used to assess sixth (N = 150; 53% girls) and ninth grade (N = 150; 50% girls) students’ current well-being and peer victimization earlier in the day on 5 random school days within a 2-week period. Associations between peer victimization microcontextual factors (number of aggressors, presence of witnesses, and receipt of help) and fluctuations in adolescents’ daily well-being (humiliation, worry, and physical symptoms) were examined in an ethnically diverse sample of White, Latino, Asian, African American, and multiethnic students. Humiliation increased on days in which students reported public victimization, multiple aggressors, and no help. Worry increased on days students experienced private victimization and when boys (but not girls) experienced private victimization, victimization by a single aggressor, and received peer help. Physical symptoms were higher on days that victimization occurred, regardless of context, but only for sixth graders and not ninth graders. These findings suggest that the victimization microcontext can offer insight about the types of peer victimization exposure that might produce the greatest daily risk for adolescents.     

The Pivotal Role of Adolescent Autonomy in Secondary School Classrooms

Student engagement is an important contributor to school success, yet high school students routinely describe themselves as disengaged. Identifying factors that alter (increase) engagement is a key aspect of improving support for student achievement. This study investigated students’ perceptions of autonomy, teacher connection, and academic competence as predictors of changes in student engagement within the classroom from the start to the end of a course. Participants were 578 (58% female) diverse (67.8% White, 25.2% African American, 5.1% Hispanic, 1.2% Asian American) high school students from 34 classrooms who provided questionnaire data both at the start and the end of a single course. Novel results from a cross-lagged model demonstrated that students who perceived their classrooms as allowing and encouraging their own autonomy in the first few weeks increased their engagement throughout the course, rather than the typical decline in engagement that was demonstrated by students in other classrooms. This finding is unique in that it extended to both students’ perceptions of engagement and observations of student engagement, suggesting a fairly robust pattern. The pertinence of this finding to adolescent developmental needs and its relationship to educational practice is discussed.