七株鹅肠道沙门氏菌的分离鉴定、药敏试验及毒力基因、耐药基因的检测

目的:对2018-2019年7个批次送检的病死雏鹅的肝脏组织进行病原菌的分离鉴定、药敏试验、毒力基因,以及药物抗性基因的PCR扩增,为畜禽相关疾病治疗提供用药指导,并对其致病机理和耐药机制进行初步探讨.方法:用病死鹅的肝组织进行病原菌分离培养、形态观察、生化试验、药物敏感试验,并提取分离菌DNA模板、16S rRNA基因序列测定并进行同源性对比,并对其相关的毒力基因和耐药基因进行PC R扩增.结果:从上述试验中分离到7株肠道沙门氏菌.7株分离菌均表现多重耐药性.2株扩增出blaterm-1基因,3株扩增出baCMY-2基因,6株扩增出卡那霉素耐药基因aasA1,7株均扩增出磺胺类耐药基因sul1,均未扩增出喹诺酮耐药基因qnr,与药敏试验结果一致.毒力基因检测结果显示:4株扩增出肠毒素基因stn和菌毛素基因inv J,3株扩增出菌毛素基因sip A,均未扩增出毒力岛基因misL和毒力岛基因ss aB.结论:7次送检鹅死亡原因是肠道沙门氏菌感染引起的.7株分离菌均含有多种毒力基因及多重耐药基因.     

体力活动、静坐行为与学前儿童体质健康的关系

体力活动和静坐行为是影响儿童早期体质健康的重要因素。本研究以152名学前儿童为被试,使用三轴加速度计测量体力活动和静坐行为,使用儿童型人体成分分析仪测量身体成分,使用《国民体质测定标准(幼儿部分)》测评身体素质,使用相关分析、多元回归分析和等时替代回归分析对它们之间的关系进行探究,结果发现在控制了性别、年龄、城乡、佩戴时间和静坐行为等因素后,中高强度体力活动尤其是高强度体力活动对去脂体重指数和身体素质(十米折返跑、立定跳远、双脚连续跳、走平衡木)依然具有显著影响;高强度体力活动替代其他强度体力活动或不同强度体力活动替代静坐行为后,去脂体重指数均有所提升;身体素质变化仅在高强度体力活动替代其他强度体力活动和静坐行为时具有方向一致性和显著性。家长和教师应充分重视中高强度体力活动尤其是高强度体力活动与学前儿童体质健康的紧密联系,促进学前儿童静坐行为和低强度体力活动向中高强度体力活动适度转化,以提升学前儿童下肢肌肉力量素质和灵敏素质等方面的体质健康水平。     

刍议"以德治国"

江泽民同志提出的“以德治国”思想是指把道德作为管理国家、调控社会的手段,来指导国家各项方针、政策的创制、实施和执行。它的提出,是对历史上“德治”思想的总结与提升,并有其丰富的理论和现实基础;民主的道德性理论、政治社会化理论、治国方略理论和德法辩证关系等。当然,在实施“以德治国”的过程中,我们还必须处理好以下几个方面的问题;坚持邓小平理论的指导、营造舆论文化环境、加强道德教育和加强党的领导等。     

A Comprehensive Approach to Technology Training for Early Childhood Teachers

This study describes the development and implementation of a comprehensive approach to computer technology training for early childhood teachers. Departing from the singular goal of conveying skills and knowledge, a comprehensive program targets the development of teachers' attitudes and practices as well as knowledge and skills. All 3 areas are regarded as equally important for the development of teacher technology proficiency. Evaluation of the program documented its effectiveness. Compared to nonparticipants, teachers in the training program had significantly higher scores in all 3 goal areas: attitudes, knowledge and skills, and practices. Results of the study indicate that a comprehensive approach is an effective means of training teachers in computer technology. Implications of the study are discussed with regard to the strategy of developing the “whole teacher” and emergence of the domain of educational technology.     

例谈理综实验复习备考策略

从2001年开始的新一轮高中课程改革至今已有八年了,按课程改革后的新教学大纲和新教材进行高考化学命题考试,全国大部分地区已进行了五年(2004-2008),今年是第五个年头。我们对这五年全国高考"理科综合"中的化学实验题(共12套,2004年卷Ⅰ是旧课程卷未列入)进行了对比分析,从中看到五年高考化学实验题贯穿了课程改革的理念,并     

对我国在线旅游服务的浅析及讨论

随着互联网的快速普及和众多消费者对自助旅游的需求,在线旅游已经成为消费者获取旅游服务的重要方式,同时很多传统企业开始涉足在线旅游提供网络服务。本文就在线旅游服务的现状和存在的问题进行了浅析,并对主要问题展开了讨论。     

The US-preexposure effect in honeybees

Signaled avoidance was studied in individual honeybees that visited the laboratory regularly to take sucrose solution from a target set on the sill of an open window. During feeding, substrate vibration or airstream was used to signal a brief shock that could be avoided by breaking off contact with the food for a few seconds. Aversive conditioning of the context was measured in terms of return time (the time between successive visits). In Experiment 1, experience with unsignaled shock was found to lengthen return time—which experience with signaled shock did not—and to impair performance in subsequent avoidance training with signaled shock (the US-preexposure effect). In Experiment 2, experience with unsignaled shock given after signaled avoidance training lengthened return time but had no effect on response to the signal in a subsequent extinction test. These results closely resemble the results obtained in analogous experiments with vertebrates.     

Controlled choice assignments: A new and more effective approach to school desegregation

The authors argue that conventional mandatory and voluntary school desegregation techniques have failed to provide minority students with maximum feasible relief from invidious discrimination because they do not redress the root causes of segregation. They demonstrate that residential-based student assignment plans as well as plans that give students limited access to a few educationally enriched magnet schools are not asymmetrical remedies to wrongful segregation and thus work to perpetuate the racial and social inequities that they purport to correct. The authors offer an alternative approach to school desegregation—controlled choice—that operates independently from residential housing patterns and which explicitly seeks to maximize personal choice within a racially unitary, equitable, and educationally enhanced system of public schooling. Controlled choice was originally pioneered in Cambridge, Mass. during the early 1980s and has recently been adopted in Little Rock, Ark., and Fall River, Mass. The policy is also being actively reviewed by several of the nation's largest school districts including Seattle, Memphis, and Boston.