930 resultados para Hopkins, Ezekiel, 1634-1690.
Resumo:
Spawning behavior and external features of the larval development were studied in the chitons Mopalia muscosa and M. lignosa during the months of April-June, 1974, at Pacific Grove, California. ... The sequence of events in the development of the two species in the same, though some differences in timing exist.
Resumo:
The activity pattern of the black turban snail, Tegula funebralis (A. Adams, 1854) at Pacific Grove, California, is the subject of this article. Field studies were carried out to follow the locomotory and feeding activities of individuals of T. funebralis, to determine how much of each animal's time was spent in each of these activities, and when and under what environmental conditions they occurred.
Resumo:
The sulfide binding characteristics of blood serum were studied in vitro in two deep-sea vesicomyid clams, Calyptogena pacifica and Vesicomya gigas. Both the C. pacifica and the V. gigas serum concentrated sulfide at least an order of magnitude above ambient levels. V. gigas accumulated sulfide faster than C. pacifica, reaching saturation at 5000 M after an hour. C. pacifica bound sulfide at half the rate of V. gigas, reaching saturation in about two hours at a substantially higher concentration of sulfide. The observed distribution of the animals near cold seeps in the Monterey Submarine Canyon can be explained by their different sulfide binding abilities. The hypothesis that cold seeps are actually much more unstable sources of sulfide than previously assumed is explored.
Resumo:
本发明涉及一种姚虻唾液腺蛋白酶tabfiblysin及其基因和应用,属于生物医学技术领域。本发明的姚虻蛋白酶tabfiblysin是从姚虻唾液腺中分离得到的一种活性蛋白质,分子量27145.5道尔顿,其全序列由255个氨基酸组成;姚虻蛋白酶tabfiblysin基因由871个核苷酸组成。本发明的姚虻唾液腺蛋白酶 tabfiblysin具有显著的水解纤维蛋白原和抑制血小板聚集的作用,能作为制备治疗血栓性疾病药物的应用。
Resumo:
Pheromones are chemical cues released and sensed by individuals of the same species, which are of major importance in regulating reproductive and social behaviors of mammals. Generally, they are detected by the vomeronasal system (VNS). Here, we first investigated and compared an essential genetic component of vomeronasal chemoreception, that is, TRPC2 gene, of four marine mammals varying the degree of aquatic specialization and related terrestrial species in order to provide insights into the evolution of pheromonal olfaction in the mammalian transition from land to water. Our results based on sequence characterizations and evolutionary analyses, for the first time, show the evidence for the ancestral impairment of vomeronasal pheromone signal transduction pathway in fully aquatic cetaceans, supporting a reduced or absent dependence on olfaction as a result of the complete adaptation to the marine habitat, whereas the amphibious California sea lion was found to have a putatively functional TRPC2 gene, which is still under strong selective pressures, reflecting the reliance of terrestrial environment on chemical recognition among the semiadapted marine mammals. Interestingly, our study found that, unlike that of the California sea lion, TRPC2 genes of the harbor seal and the river otter, both of which are also semiaquatic, are pseudogenes. Our data suggest that other unknown selective pressures or sensory modalities might have promoted the independent absence of a functional VNS in these two species. In this respect, the evolution of pheromonal olfaction in marine mammals appears to be more complex and confusing than has been previously thought. Our study makes a useful contribution to the current understanding of the evolution of pheromone perception of mammals in response to selective pressures from an aquatic environment.
Resumo:
用角膜表皮刮磨方法人工造成兔眼角膜创伤直径为10mm的圆形创面,分析小鼠表皮生长因子(EGF)对其修复的剂量关系。5个浓度EGF(100、50、20、10和0.5μm/ml)治疗的试验组痊愈时间均比对照组提前,有非常显著的差异(P<0.01),但在这5个浓度组之间,痊愈时间无显著性差异。结果表明,小鼠EGF对兔眼角膜损伤有促修复作用,实验所用的5个浓度与修复作用无剂量依赖关系。
Resumo:
Except for coastal dwellers, most Filipinos do not know what sea cucumbers are, although most must have dined on them at some time. A description is given of what sea cucumbers are and how they look, how they are processed and how they are cultured. Sea cucumbers, which belong to the families Holothuridae and Stichopodidae, have a worldwide distribution and are found in large numbers in the Indo-West Pacific region. In the Philippines, sea cucumbers have never been cultured, although it is one of the sources of dried sea cucumbers in the international market. This is most probably due to the fact that wild supply has apparently been sufficient for trading.
Resumo:
运用透射电镜及荧光显微技术 ,对富营养化的武汉东湖中浮游病毒丰度及多样性进行了研究。电镜观察和计数结果显示 ,东湖中浮游病毒的丰度达到 10 8个 /mL。荧光显微镜计数结果约是电镜计数结果的 2 72倍 ,差异极显著 (P <0 0 1)。在东湖超富营养区的水样中观察到了多种与各种病毒形态类似的颗粒 ,其中大部分与噬菌体和噬藻体类似 ,具多种形态的尾部和六边形头部。还有一些线状、杆状、子弹形等形态的病毒粒子。研究结果显示东湖水环境中的浮游病毒不仅丰度极高 ,而且种类丰富。提示浮游病毒在东湖水环境和水生态
Resumo:
中国科学院知识创新工程重大项目 (KSCXI SW 13 0 4) ; 国家重点基础研究发展计划 (2 0 0 3CB415 10 3 )资助