共查询到20条相似文献,搜索用时 62 毫秒
1.
内蒙古达茂旗腾格淖尔地区大沙鼠种群繁殖习性的调查 总被引:8,自引:1,他引:7
鼠类繁殖生态学的研究是其种群生态学研究的一个重要方面 ,它不但为研究鼠类种群数量变动规律对种群数量进行预测预报提供重要的生态学基础资料 ,也为控制鼠害措施的制定提供依据 ,同时也具有重要的流行病学意义。大沙鼠 (Rhombmysopimus)广泛分布于中亚细亚、哈萨克斯坦、伊朗、阿富汗和蒙古国等地 ,在我国主要分布于内蒙古西部、甘肃北部和新疆 ,是荒漠—半荒漠地区的重要害鼠。我国对其生态学方面多注重于种群分布格局的研究[1~ 5] ,在繁殖方面的研究甚少[6] 。 1 979~1 980年和 1 995~ 1 996年对内蒙古包头市达尔罕茂… 相似文献
2.
大沙鼠和子午沙鼠的种群生态位 总被引:14,自引:2,他引:12
大沙鼠(Rhombomysopimus)和子午沙鼠(Merionesmeridianus)均为荒漠、半荒漠的典型鼠种,为群栖性鼠类,只是子午沙鼠不像大沙鼠那样形成很大的集群。在沙质荒漠生境,大沙鼠和子午沙鼠常混居于沙丘坡地上部,成为这些地区自然群落中的优势种。对于大沙鼠和子午沙鼠种群之间的关系,在空间分布格局方面的研究已有报道[1]。作者于1995年9~10月、1996年4~5月、9~10月和1999年10月在内蒙古包头市达尔罕茂名安联合旗北部的腾格淖尔地区,对大沙鼠和子午沙鼠种群生态位进行了研究,并就它们对资源的利用和分配以及两… 相似文献
3.
北京地区黑线仓鼠年龄鉴定及种群年龄组成的研究 总被引:10,自引:2,他引:8
鼠类种群年龄组成的研究是种群生态学的基础内容。种群年龄组成的变化,直接关系到鼠类数量的波动。黑线仓鼠(Cricetulus barabensis)是北京地区农田的主要害鼠之一,为探讨该鼠种在农田生态系统中的作用,并控制其危害,研究其种群年龄组成及变化是非常必要的。 相似文献
4.
5.
6.
7.
长爪沙鼠(Meriones unguiculatus)是荒漠草原的典型鼠种,但它的分布十分广泛。在内蒙古除呼伦贝尔盟大兴安岭林区、兴安盟和阿拉善盟沙漠地区外,几乎到处都有分布,其中尤以西部荒漠草原和大青山以南的农业区数量最多。它除了危害农牧业外,并是动物源疾病的重要的疫源动物之一。革螨在各种鼠类的鼠体 相似文献
8.
Leslie 矩阵在大沙鼠种群动态研究中的应用 总被引:1,自引:0,他引:1
2002~2003年通过对精河甘家湖荒漠梭梭林国家级自然保护区大沙鼠的实地调查,采用样方面积夹子法、堵洞盗开法、样地捕净法,捕获大沙鼠173只,其中雄94只,雌79只。用胴体重为指标划分年龄。经Leslie矩阵推演,其数量变动表明,近几年该种群保持在相对稳定的水平,两三年内数量不会有大的变动。 相似文献
9.
10.
社鼠的年龄鉴定与种群年龄组成 总被引:28,自引:9,他引:19
年龄组成是种群的重要特征之一。分析年龄组成中不同时期各年龄组数量的比例,有助于了解种群数量变动的规律。寿振黄等(1959)以臼齿齿根的分岐与否和前后根的长度作为红背(鼠平)的年龄标准。罗泽珣(1963)和诸葛阳等(1959、1978)分别用臼齿磨损程度和体重来划分黑线姬鼠的年龄。国外有以晶体干重为依据分析年龄组成,如Lord(1959),Adamczewska-Andrzejewska(1972),Geurley(1975),Yabe(1979)等分别对白尾兔(Cottontail rabbit)、黑线姬鼠(Apodemus agrarius)2种田鼠(Microtus pinetorum和Microtus montanus)、和褐家鼠(Rattus norvegicus)进行了不少工作。 相似文献
11.
12.
Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
13.
14.
15.
16.
17.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases 相似文献
18.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme
responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare
the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show
that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by
distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of
demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least
one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of
the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable
potent antiproliferative synthetic drugs. 相似文献
19.
RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
20.
JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献