子午沙鼠种群数量动态及预测

子千沙鼠（Ｍｅｒｉｏｎｅｓ ｍｅｒｉｄｉａｎｕｓ）是荒漠和半荒漠地区常见的鼠种之一,作者于１９９１～、９９５年４～１０月每月中旬,在内蒙古达拉特旗中国农业守草原研究所鄂尔多斯沙地草场改良试验站,利用直线夹日法在站内的流动消逝天,半流动消逝一,固定沙地,丘间滩地,林地和农田中开展了种群数量调查。６ａ共布放１２４２４５闪日,捕获鼠７４９８只,其中子午沙鼠１４０８只,在各种鼠中占１８．７７％,居第二位。     

大沙鼠的年龄鉴定与种群年龄组成

在鼠类生态学的研究中 ,对鼠类年龄的鉴定是一项重要的工作。年龄组成是种群的重要特征之一 ,它有助于了解种群的年龄结构以及种群数量变动的规律。大沙鼠 (Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ)是中亚地区荒漠及半荒漠草原的重要害鼠之一 ,在内蒙古西部的梭梭 (Ｈａｌｏｘｙｌｏｎａｍｍｏｄｅｎｄｒｏｎ)林区 ,由于大沙鼠的啃咬 ,影响了该地区梭梭林的正常结实 ,从而降低了结实量[1 ] 。同时 ,大沙鼠又是鼠疫和皮肤利什曼病的重要宿主。对大沙鼠的年龄鉴定与种群年龄组成进行研究 ,将有助于了解其种群数量变动的规律 ,从而为有效防治大沙鼠鼠…     

大沙鼠,子午沙鼠,长爪沙鼠腰带骨的研究

主要研究大沙鼠(Rhombomys opimus)、子午沙鼠(Meriones meridianus)、长爪沙鼠(Meriones unguiulatus)腰带骨的比较,研究材料共30只骨骼标本均为成体。从测量中发现,它们之间差异比较突出,其主要特点: 1.腰带骨指数大沙鼠小于50,而子午沙鼠和长爪沙鼠都大于50。 2.大沙鼠坐骨弓指数在100以上,长爪沙鼠90以下,子午沙鼠80以下。说明大沙鼠坐骨弓较深。子午沙鼠和长爪沙鼠骨盆联合指数都小于大沙鼠。     

内蒙古达茂旗腾格淖尔地区大沙鼠种群繁殖习性的调查

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…     

不同干扰荒漠生境中子午沙鼠的繁殖及种群动态特征

子午沙鼠(Merionesmeridianus)广泛分布于我国西北部地区,是荒漠啮齿动物群落的优势鼠种。种群繁殖特征是动物生活史参数中的一个重要组成部分,是种群数量补充的重要来源,而干扰是影响繁殖特征的重要因素。本研究于2012~2014年,在位于蒙古阿拉善左旗南部典型荒漠的野外实验区,设置禁牧、开垦、过牧、轮牧4种不同干扰样地,使用铗日法对实验样地子午沙鼠相对数量及繁殖特征进行调查。4种不同干扰生境中的子午沙鼠种群数量具有显著差异,禁牧过牧轮牧开垦;雌雄性比在轮牧生境中最高,开垦生境次之,禁牧生境最低;4种干扰生境中,轮牧样地子午沙鼠雌鼠怀孕率显著高于禁牧、过牧和开垦样地;雄鼠的睾丸下降率在过牧干扰样地显著高于其他3种干扰方式样地,轮牧样地雄鼠睾丸下降率最低;雌鼠平均胎仔数在4种干扰生境间无显著性差异;轮牧干扰样地繁殖指数显著高于其他3种干扰方式样地;繁殖指数、怀孕率及睾丸下降率对密度的反馈作用最为明显,但在不同的干扰生境中其反馈特征有差异。综上,子午沙鼠在轮牧生境中各繁殖特征指数最高,繁殖能力最强,种群密度相对较高,更适合其生存,其密度制约效应表现最为明显。     

大沙鼠和子午沙鼠种群空间分布格局的研究

采用最近邻体法、Ｔ形取样法和负二项分布法对内蒙古达茂联合旗腾格淖尔地区的大沙鼠和子午沙鼠空间分布格局进行了研究。结果表明,大沙鼠一年四季均为聚集分布,子午沙鼠在冬春季为均匀分布,在夏秋季为聚集分布。二种群间在冬春季为聚集或均匀分布,在夏秋季为明显的聚集分布。对二者空间分布格局进行相关性检验,冬春季二者为负相关,夏秋季为正相关。     

子午沙鼠种群繁殖特征分析

子午沙鼠（Ｍｅｒｉｏｎｅｓｍｅｒｉｄｉａｎｕｓ）是我国西北各省（区）荒漠草原的代表鼠种和优势鼠种。本文将１９９１～１９９６年在库布齐沙漠东段该鼠的繁殖调查资料报道如下。１材料与方法１１调查基点概况调查基点设在内蒙古伊克昭盟达拉特旗境内的中国农业科学...     

河西荒漠子午沙鼠的生态学初步观察

子午沙鼠Meriones meridanus Pallas是一种荒漠、半荒漠地区的小型啮齿动物。研究子午沙鼠生态学对这些地区的开发利用和防治鼠害具有很大意义。1961年4月—6月,在甘肃酒泉黑山湖地区进行了子午沙鼠生态调查,结果如下:一、不同栖息地的分布与数量剖检从各种不同栖息地捕获的子午沙鼠36只,发现每只鼠胃内食物平均重3.1克,(1.5克～7克),一般为2.5～3.5克。鼠胃的内容物中黄色食糜(枸杞叶)占44.7%,绿色(盐爪爪的叶和茎的表皮、东蔷叶)占30.4%,白色和褐色及其他(主要是东蔷种子,部分为其根、茎的韧皮部)分别占8.5%和16.4%。在剖检鼠胃的过程中…     

蒙新区子午沙鼠种群的遗传多样性和遗传结构

为了探讨蒙新干旱区景观和环境因素对子午沙鼠种群遗传结构的影响,我们利用8 个多态性的微卫星位点,对子午沙鼠14 个局域种群的160 个个体进行了种群遗传多样性和遗传结构的分析。微卫星结果显示种群具有高的遗传多样性,微卫星位点的等位基因数(A)为22. 50 ±3.02 (19 ～ 28),多态信息含量(PIC)为0.912 ±0. 02 (0.872 ～ 0. 929);种群观测杂合度(HO )为0.68 ± 0. 19 (0. 52 ～0.85),期望杂合度(HE )为0.79 ± 0. 08(0. 71 ～ 0.85)。分子变异分析(AMOVA)结果显示,所得到的3 个组之间已发生显著的遗传分化(P < 0. 001)。
Mantel 检测结果表明,子午沙鼠种群遗传结构与地理距离无显著的相关性(P = 0.270 0),而在多元线性模型中,蒙新干旱区的海拔高度是影响种群遗传结构的关键因素。     

三种沙鼠躯干骨及四肢骨的比较

大沙鼠(Rhombomys opimus)与子午沙鼠(Meriones meridianus)、长爪沙鼠(M.ungui-culatus)为我国广泛分布的沙鼠亚科(Gerbillinae)的3个种类。对它们的研究,前人多偏重于外部形态及生态学的观察,而解剖学方面的报道不多。1988年,作者研究了这3种沙鼠躯干骨和四肢骨,为阐明它们的形态结构特点积累资料,供读者参考。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).