关键词： Rodents   Savanna   Biomass   Population density   Energetics   Trappability  

摘要： Dry season densities of small non-fossorial rodents in five different savanna habitats ranged from 11 to 41 animals h-1 with corresponding live weights ranging from 310 g to 1557 g ha-1. Average biomasses of small rodents in two representative savanna types, Burkea and Acacia savanna, were 912 g ha-1 and 816 g ha-1 respectively. These biomasses were similar to or even exceeded biomasses of other important consumers (birds, cattle, impala, and grasshoppers) in the savanna. Due to allometric relationships 1 kg of small savanna rodents is equivalent in energy cosumption to 8 kg of impala (Aepyceros melampus) or 12.7 kg of cattle. The potential effect of small rodents on the savannah is therefore much larger than previously thought and need further investigation.

关键词： 树河组   二叠纪   盐源   动物化石   灰岩   早二叠世   石炭纪  

摘要： 1965年,丁蕴杰等在四川盐源测制剖面时,将下二叠统底部的一套砾状灰岩地层称为树河组,并以盐源树河牛厂甘沟梁子为其建组剖面,提出该区石炭纪与二叠纪的生物共生现象。1981年,四川攀西地质大队区调三队将此套含砾地层归于上石炭统一下二叠统,以盐源树河小槽梁子剖面为其代表。1982年,詹立培等将这套砾状灰岩层位与贵州龙吟组对比,将其中生物化石称为混生动物群。近年来,我所与成都地质学院师生在盐源西部及云南宁蒗泸沽湖等地测制剖面,在相同层位上见明显的生物混杂现象,乃构造破坏后再沉积的产物。

关键词： 动物学家   动物国   玛丽   规划处   斯科特   四年   博物学家   圆木   古生物学家   鸟鸣  

摘要： <正> 一走进“树厅”的大门,你就进入了一个奇妙的世界。在这里你会觉得自己变成了一只青蛙或一只蜜蜂:你可以钻出蛋壳或茧皮;也可以观察水底的游鱼或夜行动物的行迹;还可以让蟋蟀吟唱,让恐龙鸣吼。这一奇妙世界叫作“树厅”,建造在一所百年之久的建筑里,它是由建筑师、动物学家、雕塑家、美术师和发明家共同建造的,其设计和施工用了近四年时间。“树厅”是一个让孩子们通过游戏学习自然环境知识的场所。建造“树厅”的想法是费城动物园规划处主任玛丽一斯科特·西布尔提出的。她说:“我一直在琢磨创建一种场景,使孩子们在其中对大自然感到敬畏或融为一体。我想,

关键词： Biology   Amblyseius olivi Nasr & Abou-Awad   Phytoseiidae   Acari   predacious mites  

摘要： The development was faster and reproduction was higher when Amblyseius olivi Nasr and Abou-Awad fed on the eriophyid mite Eriophyes olivi Zaher and Abou-Awad. The duration increased and reproduction decreased on the tetranychid mite Tetranychus (T.) urticae Koch. The predator female consumed daily 120 and 8 individuals of E. olivi and T. (T.) urticae respectively. The daily reproduction was as low as 0.6 - 0.3 eggs/.female./day when females were maintained on royal jelly, molasses, honey or their combinations.

关键词： 臭鼩   树鼩   高重顺序  

摘要： 将臭鼩肾组织提取的高分子量DNA经BamHⅠ、BglⅡ,EcoRⅠ酶解后,获得高重顺序,提纯BM(BamHI)-1片断,测定其分子量,进行酶切位点分析以及测定臭鼦DNA的Tm值,并同树鼩的高重顺序进行杂交。结果表明,臭鼦在高重顺序酶切片段电泳带型、单体分子量大小,酶切位点分布等方面与树鼩有较大差异。杂交结果亦表明两者高重顺序的同源性较小。

关键词： Bark   Tree trunks   Pendulums   Microclimates   Pine trees   Fauna   Forest ecosystems   Arthropods   Surface temperature  

摘要： The thermal properties of four different types of bark were investigated on twentyfour central European tree species using thermocouples. Tree species with white bark avoided overheating of their surface by reflection of the radiation. Species with fissured and scaly barks shade inner parts of their bark. Some tree species with fissured barks show high insulation across the bark. Smooth and thin barks show no adaptation to avoid overheating. These tree species (in central Europe e.g. Fagus sylvatica) have to form closed stands and are not able to occur in open stands as tree species with structured or white bark types. The arthropod fauna of the same bark types was studied on six tree species [F. sylvatica, Betula pendula, Quercus robur, Ulmus glabra, Salix alba, and Acer pseudoplatanus] using three collecting methods. The microclimate on the bark determines the number per cm2 of some species, some are active during winter, and other tend to aptery and reproduce parthenogenetically. On smooth bark one species dominates, whereas a highly diverse fauna lives on fissured barks. The occurrence of species on bark is determined by the microstructure, microclimate and consistence of the epiphyts. If tree species alter within forest ecosystems the dominant species on bark will persist. Specialists of fissured barks will die out if tree species with smooth bark (Fagus sylvatica) form the central European forest.

关键词： HDL   实验组   血清   试验组   胆甾醇   胆固醇   脂蛋白   动脉硬化   动脉粥样硬化  

摘要： 目前研究HDL抑制粥样斑块的机理是防治动脉粥样硬化病的一个重要课题。我们在利用树鼩建立粥样斑块模型中发现,树鼩具有很高的血清α脂蛋白(占总脂蛋白60～75％),用高于家兔4～5倍高胆固醇长期摄入,仍不形成典型的粥样病变。实验先后进行了二次,历时3年。第一次实验有22只树鼩,雌雄各半,分2组。实验组12只,平均体重130.5±11.2克,每周喂6次胆固醇饲料(胆固醇0.2克、蛋黄

关键词： 系统树   节肢动物   进化分枝图   动物进化   环节动物   腔肠动物   扁形动物   裂体腔动物   原口动物  

摘要： 系统树(phylogenetic tree)又叫系统树图(dendrogram)、谱系树(genealogical tree)或进化树。分类学家和进化论者为了简明地表示出生物的亲缘关系及进化历程,常根据亲缘关系的远近,将各类生物分别放在一种有分枝的树状图表上,这种图表,就是系统树。大家知道,达尔文的进化论中有一条基本原理:各类生物都由共同祖先传衍而来,它们之间有或近或远的亲缘关系。达尔文指出,一切哺乳动物都来自一个始祖种;一切昆虫都有

关键词： 紫树   根皮   粗提物   提取物   蓝果树   动物   亚急性毒性   亚慢性毒性   移植瘤   实验研究  

摘要： 紫树,又名兰果树(Nyssa,sinensisoliver,属珙(王同)科(Nyssaceae),是我国特有植物,与抗癌植物喜树(Camptothe-ca accuminata Decne)为同科。紫树系乔木,高10～18米,因其幼枝及核果紫兰色而得名,成片分布于长江流域及华南各省区的海拔800～1400米森林中。喜树对动物移植瘤有抑癌作用,根据其与喜树的同科亲缘关系。本文报道紫树提取物对