短期低浓度混合重金属污染对鲫鱼乳酸脱氢酶活性的影响

为了探讨低浓度混合重金属污染物短期内对鲫鱼乳酸脱氢酶(LDH)活性的影响,于2010年10月至2011年1月,选用鲫鱼(Carassius auratus)为研究对象,以煤矸石浸出液作为低浓度混合重金属污染物,在实验室条件下研究了鲫鱼LDH酶活力的变化.结果表明:试验组LDH活力的平均值(0.995±0.078)显著高于对照组LDH活力的平均值(0.943±0.167),表明短期低浓度混合重金属污染增强了鲫鱼LDH的活力.     

Antioxidant activity and protective effect of Clitoria ternatea flower extract on testicular damage induced by ketoconazole in rats

Background

Ketoconazole (KET), an antifungal drug, has adverse effects on the male reproductive system. Pre-treatments with antioxidant plant against testicular damage induced by KET are required. The flowers of Clitoria ternatea (CT) are proven to have hepatoprotective potential. However, the protective effect on KET-induced testicular damage has not been reported.

Objective

To investigate the protective effect of CT flower extracts with antioxidant activity on male reproductive parameters including sperm concentration, serum testosterone level, histopathology of the testis, and testicular tyrosine phosphorylation levels in rats induced with KET.

Methods

The antioxidant activity of CT flower extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Male rats were treated with CT flower extracts (10, 50, or 100 mg/kg BW) or distilled water via a gastric tube for 28 d (preventive period: Days 1–21) and induced by KET (100 mg/kg BW) via intraperitoneal injection for 7 d (induction period: Days 22–28). After the experiment, all animals were examined for the weights of the testis, epididymis plus vas deferens and seminal vesicle, serum testosterone levels, sperm concentration, histological structures and diameter of testis, and testicular tyrosine phosphorylation levels by immunoblotting.

Results

The CT flower extracts had capabilities for DPPH scavenging and high reducing power. At 100 mg/kg BW, the extract had no toxic effects on the male reproductive system. Significantly, in CT+KET groups, CT flower extracts (50 and 100 mg/kg BW) alleviated the reduction of reproductive organ weight parameters, testosterone levels, and sperm concentration. In addition, CT flower extracts gave protection from testicular damage in KET-induced rats. Moreover, in the CT100+KET group, CT flower extracts significantly enhanced the expression of a testicular 50-kDa tyrosine phosphorylated protein compared with that of other groups.

Conclusions

C. ternatea flower extracts possessing antioxidant activity are not harmful to the male reproductive system and can protect against testicular damage in KET-induced rats.     

Toxicity of cadmium to soil microbial biomass and its activity：Effect of incubation time on Cd ecological dose in a paddy soil

INTRODUCTION Cadmium (Cd) is ubiquitous in the human en-vironment and has been recognized as one of the mostdeleterious heavy metal pollutants (Robards andWorsfold, 1991; Christine, 1997). It may easily movefrom soil to food plants through root absorption andaccumulate in their tissues (Oliver, 1997). In this way,Cd may enter the food chain and affect human health(Adriano, 1986). Among many heavy metals pollut-ing soil, Cd is of concern because of its potentiallyharmful effects on…     

A study of the relationship between expression level of TRF1 protein and telomerase activity in human acute leukemia

INTRODUCTION Telomeres are distinctive DNA-protein struc-tures that cap the ends of linear chromosomes.It is very important to keep the chromosomes stabilization.Telomerase activity is closely linked to attainment of cellular immortality,a step in carcinogenesis,while lack of such activity contributes to cellular senes-cence.Telomerase is activated in more than85%ofmalignant tumors(Hiayma et al.,1997).Human te-lomeric repeat binding factor1(TRF1)is a telomere associated with proteins a…     

The effect of activity type on the engagement and interaction of young children with disabilities in inclusive childcare settings

The engagement and adult and peer interaction of 37 young children with a range of disabilities was measured in free play, group, and meal-routine activities in inclusive childcare settings. A significant effect for activity type was found for total engagement, active engagement, and passive engagement, with the children being more engaged in free-play and meal-routine activities than group activities. Free-play and meal-routine activities provided better opportunities for active engagement than did group activities, but children were more actively engaged during meal-routine activities than during free play. Passive engagement was more commonly observed during group activities. Children interacted more with their peers during free play. When children with a diagnosis of autism spectrum disorder were compared with children with other disabilities, they were found to be significantly less engaged during free play and interacted less with their peers. The implications of these findings for inclusive practice in childcare settings are discussed.     

图书馆在构建和谐社会中改革发展的思考

将图书馆由单纯的藏书和借还书的机构,改造成宣传先进文化的多功能活动中心,我国古代就有很好的经验,当代也有成功的实践。文章根据构建社会主义和谐社会的要求,在总结历史经验的基础上,对把图书馆建设成为宣传先进文化的多功能活动中心提出了具体意见,以使图书馆在构建社会主义和谐社会中发挥更大作用。     

北宋神宗时期徐州文人活动研究——以苏轼、秦观、陈师道为中心

宋代文人具有强烈的结盟意识,几乎每个时期都出现过引领风气的文坛盟主。笔者以苏轼、陈师道、秦观等主要作家为切入点,对北宋熙宁、元丰间的徐州文人交游唱和活动展开研究。该活动历时两年,始终以苏轼为中心,参与者既是朋友又是师生,基于共同的人生志趣和文学追求,在徐州寻胜访幽、诗酒酬唱,翰墨往来不断,创作了大量的诗文。这不仅为当时的文坛增添了新的因素,而且对北宋后期及后世的文学观念与创作产生了深远的影响。     

海峡西岸经济区与长三角、珠三角经济区城市生态化水平的比较研究

生态城市是根据生态学原理而建立的经济高效、社会和谐、生态良性循环的城市,也是人类基于生态文明的觉醒而选择的理想居住模式.选取海峡西岸经济区与长三角、珠三角经济区这三大经济区34个地级以上城市作为研究对象,从经济、环境和社会三个方面构建了适用于研究区域的生态城市评价指标体系,并在此基础上利用因子分析、聚类分析等方法定量地对这34个城市进行生态化建设水平的综合评价与分析,并通过比较着重分析了海峡西岸经济区城市生态化建设中存在的问题并提出对策.     

农村小学综合实践活动课程实施的现状及对策——以广西桂林雁山区农村小学为例

农村小学的综合实践活动课程是其校外教育的重要组成部分,但其实施面临着资源短缺且未能充分开发利用;师资力量薄弱导致教学效果不佳;学生安全制约着活动课程的开展等问题。为此提出了：落实安全责任、建立安全机制;深化各种合作、促进资源的高效利用;根据本地区特色开发校本课程、采用灵活的教学方法实施教学;拓宽资金来源渠道,尝试通过金融手段为教学活动的开展筹集必备资金的对策。     

Comprehensive sexuality education,culture and gender: the effect of the cultural setting on a sexuality education programme in Ethiopia

Comprehensive sexuality education (CSE) is recognised as an effective method of sexual health education, with the school identified as a fitting site of implementation. Its holistic and participatory nature endeavours to develop the knowledge, attitudes and life-skills of students to help them secure their sexual and reproductive health and rights (SRHR). This qualitative study aimed to better understand aspects of CSE implementation in one context. Specifically, it focuses on the effects of the cultural setting, considering how gender and sexuality norms influence teacher and student implementation strategies. The research was carried out in one secondary school in Ethiopia, which delivered a Dutch-developed programme throughout 2013. Over 50 in-depth interviews were conducted with teachers and students, influential community members and experts in SRHR. Data were also gathered through focus group discussions and classroom observations. Results show that CSE teachers and students, both male and female, were able to discuss issues of sexuality. However, the cultural context was seen to affect interpretation of programme information, influencing the nature of this discussion. For an impactful implementation, it is recommended that sexuality education aims to engage with and involve the wider community, to reduce contradictory messages and increase programme support. Furthermore, teachers should undergo extensive and comprehensive pre-programme training that addresses their attitudes and values, not just their knowledge.     

The negative effect of school-average ability on science self-concept in the UK,the UK countries and the world: the Big-Fish-Little-Pond-Effect for PISA 2006

Research on the relation between students’ achievement (ACH) and their academic self-concept (ASC) has consistently shown a Big-Fish-Little-Pond-Effect (BFLPE); ASC is positively affected by individual ACH, but negatively affected by school-average ACH. Surprisingly, however, there are few good UK studies of the BFLPE and few anywhere in the world based on science self-concept (S-ASC). Addressing this substantive limitation in existing research with data from PISA 2006, we extend new multigroup doubly-latent multilevel structural equation models – a substantive-methodological synergy. BFLPE predictions for S-ASC are supported for: the total international sample; the total UK sample; each of the four UK countries considered separately. The BFLPE was marginally larger in the UK than the international sample. However, consistent with the selective nature of school systems in the UK, the BFLPE was larger in Northern Ireland and, to a lesser extent, England than in Scotland or Wales.     

“I have a little,little, little footprint on the world” and “I’m not political”: feelings of low self-efficacy and the effect of identity on environmental behaviour in educators

Abstract

Environmental educators in both formal and informal settings work to develop students’ environmental literacy, with the goal of developing adult citizens who care about the environment and are knowledgeable and prepared to engage in behaviours to address environmental issues. Yet little attention has been paid to educator environmental literacy. Here we report the findings from an interview study of formal educators from K-12 settings and informal educators from out-of-school settings. Overall, educators favoured personal-level behaviours. In addition, some educators reported poor environmental self-efficacy for three main reasons: the scale of the problem, other negative environmental behaviour that offsets positive behaviour, and the need for system-level behaviour Educators rarely engaged in system-level behaviour due to distrust of the system, inexperience, and the rejection of political or activist identity.     

联系实际重应用、规范操作求实效--襄樊电大水利水电专业实践性教学环节的设计与成效

襄樊电大水利水电专业的实践性教育环节,注重培养学生体验和感受生活、发现和解决问题的创新精神和实践能力,从课程设计,到测量教学实习、水资源调研实习、生产实习直至完成毕业设计,均做到了有的放矢,突出实用性,注重理论知识向实践能力的转化。培养出的毕业生在思想素质、专业知识水平、业务能力和工作业绩诸方面,均得到了用人单位的认同和好评。