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关键词： 巢湖流域   生物指数   健康评价   大型底栖动物  

摘要： 由于长期暴露在自然环境中,底栖动物可整合不同时间尺度的物理、化学及生物信息,能反映污染物质对其造成的协同危害特征,因而被广泛应用于水体健康评价。为了弄清巢湖流域水体污染状况,于2009年4月对巢湖流域大型底栖动物进行采样调查。59个采样点中,鉴定出大型底栖动物共23种,其中:环节动物门6种,占26.1%;节肢动物门8种,占34.8%;软体动物门9种,占39.1%。尽管不同栖息环境中底栖动物的优势种有较大变化,但霍甫水丝蚓(Limnodrilus hoffmeisteri)、苏氏尾鳃蚓(Branchiura sowerbyi)和铜锈环棱螺(Bellamya aeruginosa)为整个巢湖流域优势物种。河流综合生物污染指数评价结果表明,巢湖流域水体均已受到不同程度的污染,南淝河的污染程度>白石山河>派河>巢湖湖体>柘皋河>杭埠河>裕溪河>丰乐河,这一结果与水质指标评价结果基本一致。

关键词： 课程标准   初中生物   动物类群   教材编写  

摘要： 修订之后的2011年版生物学课程标准在具体内容方面新增了部分动物类群。探讨课标作此修订的意义，并对课标和教学大纲中的动物类群内容进行对比分析，认为课标增加动物类群内容不是回到教学大纲的要求，而是引导学生从生物多样性的高度认识动物的多样性，内容上比教学大纲有很大简化。建议在编写教材中动物类群内容时注意几个问题：内容应符合初中学生的认知水平、重视重要的生物学概念、安排适当数目的探究活动、联系学生的生活实际。

关键词： Structure   Formation   Sperm  

摘要： The structure of the spermatozoa and spermatogenesis of the lottiid limpet Patelloida latistrigata is described by transmission electron microscopy. Although the lengths of the spermatozoa (about 60 mu m) and their head region (about 12 mu m) are similar to those of other patellogastropods, the structure of the sperm head and midpiece are very different. The head consists of an unusually large acrosome (about 11-mu m long) with a broad posterior invagination that houses the relatively small nucleus. The midpiece mitochondria, which are rather elongate with large folded tubular cristae, are housed in a cytoplasmic sheath posterior to the nucleus. The proximal centriole is unusually elongate (about 2-mu m long). The axoneme that emerges from the distal centriole is surrounded anteriorly by the cytoplasmic sheath in which the cytoplasmic side of the plasma membrane has electron-dense material. The flagellum is enlarged at its terminal end. Spermatogenesis is similar to that described for other patellogastropods. Patelloida latistrigata, therefore, has spermatozoa that seem to meet the morphological criteria of ent-aquasperm, which raises the question of whether fertilization is truly external in this limpet. However, it is also possible that the modifications to the sperm are linked to unknown specializations of the egg or egg envelope.

关键词： toxicologic pathology   uterine carcinogenesis   rodent pathology   safety assessment   reproductive system   endocrine disrupters  

摘要： Endometrial stromal polyps (ESP) are a common spontaneous reproductive tract lesion in the female rat. However, there is limited information concerning the etiology, biology, and significance of these polyps as an end point in toxicology and carcinogenicity studies. This paper reviews relevant literature to address these aspects of ESP with respect to potential relevance to human uterine tumors. Endometrial stromal polyps in rodents appear as age-related lesions. There are only a few chemicals tested for carcinogenicity in rat and mouse cancer bioassays associated with increased incidence of ESP with no common characteristics or mechanism of action. Uterine endometrial polyps that occur in women and the uterine stromal polyps that occur in rodents have distinct characteristics, although both types of uterine lesions are common, benign, and noncancerous. Human endometrial polyps develop from both endometrial and stromal components, whereas rodent polyps develop from the stromal component of the uterus. Endometrial polyps in women are hormone sensitive, but there is no scientific or experimental evidence to date that suggests that uterine stromal polyps in rodents are hormone sensitive. Therefore, based on differences in their etiology and biology, endometrial stromal polyps observed in rodent toxicity and carcinogenicity studies appear to have limited relevance to human endometrial polyps occurring in women.

关键词： 野外实习   科研素质   教学环节  

摘要： 本文总结了如何在生物学野外实践教学环节中培养学生的科研素质。培养学生的科研素质应重视如下几个重要的环节,包括实习前材料准备和学生的分组、具体的实施过程和实习考核和成绩评定几个方面。

关键词： 东钱湖   大型底栖动物   群落结构   空间分布   水质评价  

摘要： 2009年4月—2010年1月,对东钱湖大型底栖动物群落结构及空间分布格局进行了季度调查,并对其环境状况进行生物学评价.共记录底栖动物3门4纲28属30种,其中寡毛类5种、水生昆虫18种、软体动物7种.底栖动物密度、生物量和群落周年次级生产量分别为1 233 m-2、8.0 g/m2(以湿质量计)和35.3 g/(m2.a)(P/B系数法估算),单因素方差分析显示,秋、冬季显著高于春、夏季.东钱湖底栖动物优势种为红裸须摇蚊、长跗摇蚊、菱跗摇蚊和霍甫水丝蚓,红裸须摇蚊为冬季单一优势种.依据底栖动物密度的多维序列分析,可将东钱湖分为4个湖区.基于GIS平台,运用克里格插值法,构建动物参数及BI(Hilsenhoff生物指数)的空间分布格局,显示东钱湖底栖动物群落具有较强的空间异质性:摇蚊幼虫多分布在谷子湖及中部湖区,而软体动物主要聚集在中部偏西南及北部湖区.BI评价结果表明,东钱湖的整体水质为中度污染(BI为7.58),其在时空上有较大差异.其中,2009年4、7、9月为轻度污染(BI为6.66～7.33),2009年11月—2010年1月为中度污染(BI为8.32～8.39);在空间尺度上,中部及北湖偏东部湖区污染较轻,其次为谷子湖及五里塘湖区,南湖偏南部湖区污染较重.

关键词： 苜蓿多糖   生物学功能   免疫调节   动物生产  

摘要： 苜蓿多糖是苜蓿中所含有的一类生物大分子聚合物,具有广泛的生物学活性。本文从苜蓿多糖的理化性质、提取工艺、生物学功能以及其在动物生产上的应用等方面的研究进展进行了综述。

关键词： 生物学特点   肿瘤侵犯   下腔静脉   动物模型   肾静脉   VX2   临床报道   兔  

摘要： 临床上腹膜后肿瘤侵犯下腔静脉（IVC）的临床报道较多，但难以在早期被发现，预后也极差。目前，临床上对恶性肿瘤侵犯肾静脉以上、以下下腔静脉处理原则、方式尚有争议。本研究旨在比较兔VX2肿瘤侵犯肾静脉以上和以下下腔静脉动物模型生物学特点。

关键词： Object categorization   Object recognition   Error-driven learning   Hierarchical model   Feedforward processing   Comparative cognition   Avian vision   Pigeon   Computational model   Animal models   Visual cortex  

摘要： Previous comparative work has suggested that the mechanisms of object categorization differ importantly for birds and primates. However, behavioral and neurobiological differences do not preclude the possibility that at least some of those mechanisms are shared across these evolutionarily distant groups. The present study integrates behavioral, neurobiological, and computational evidence concerning the "general processes" that are involved in object recognition in vertebrates. We start by reviewing work implicating error-driven learning in object categorization by birds and primates, and also consider neurobiological evidence suggesting that the basal ganglia might implement this process. We then turn to work with a computational model showing that principles of visual processing discovered in the primate brain can account for key behavioral findings in object recognition by pigeons, including cases in which pigeons' behavior differs from that of people. These results provide a proof of concept that the basic principles of visual shape processing are similar across distantly related vertebrate species, thereby offering important insights into the evolution of visual cognition.