棕色田鼠种群年龄的研究

１９９１年２月至１９９２年４月,在河南省灵宝市、卢氏县捕获棕色田鼠１１１６只（雄５１５．雌６０１）,应用洞体重作指标,参考繁殖状况及毛色,将种群划分为５个年龄组：Ⅰ．幼体组,≤１１．５ｇ;Ⅱ．亚成体组,１１．６一２０．５ｇ;Ⅲ;成体Ⅰ组,２０．６一２６．０ｇ;Ⅳ。成体Ⅱ组,２６．１一３０．５ｇ;Ⅴ老体组,＞３０．６ｇ。对比体重、体长及头骨量度,胴体重法较能客观反映年龄状况。随季节变化,春季Ⅰ、Ⅱ组占优势,夏季Ⅱ、Ⅲ组占优势,秋季、冬季Ⅴ组数量增加,而其它各组的数量比较均匀。     

四川短尾鼩种群年龄鉴定的研究

为给四川短尾鼩年龄鉴定提供科学合理的鉴定方法,对1996～2012年贵州省大方县捕获的134只四川短尾鼩(雌性86只,雄性48只)体重统计分析。结果表明:四川短尾鼩平均体重为(31.12±6.48)g。根据体重的频次分配特征,参照其繁殖状况,将四川短尾鼩划分为5个年龄组,制定了各年龄组的体重划分标准:幼年组(Ⅰ)体重≤23.0g,亚成年组(Ⅱ)23.1～28.0g,成年Ⅰ组(Ⅲ)28.1～33.0g,成年Ⅱ组(Ⅳ)33.1～38.0g,老年组(Ⅴ)>38.0g。体重与胴体重、体长之间具有极显著的正相关关系,依据体重与胴体重的回归方程,制定了各年龄组的胴体重划分标准:幼年组(Ⅰ)胴体重≤15.0g,亚成年组(Ⅱ)15.1～19.0g,成年Ⅰ组(Ⅲ)19.1～23.0g,成年Ⅱ组(Ⅳ)23.1～27.0g,老年组(Ⅴ)>27.0g。不同年龄组体重、胴体重之间具有显著差异,随着种群年龄的增长而不断增加。不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长,种群繁殖力不断增加,参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组和老年组,平均怀孕率为37.10%,平均睾丸下降率为72.00%,平均繁殖指数为1.39。种群年龄组成具有明显的季节变化。     

捕杀对高原鼢鼠种群年龄结构及繁殖的影响

捕杀高原鼢鼠后,残鼠种群与自然种群年龄结构相比较,５月差异性显著（Ｘ２＝９９７,Ｐ＜００５）;７月和１０月差异极显著（Ｘ２＝１５１３４,Ｘ２＝１５６１２,Ｐ＜００１）。５月,残鼠种群成年Ⅰ组占最大比例（５３４５％）;自然种群成年Ⅱ组占最大比例（４８４４％）。７月,残鼠种群幼年组和亚成年组所占比例之和（３５０６％）明显高于自然种群（２２００％）（Ｐ＜００５）。１０月,残鼠种群近老年组和老年组所占比例之和（９６２％）明显低于自然种群（２３０８％）（Ｐ＜００５）。残鼠种群成年Ⅰ组雌鼠怀孕率（８４６２％）明显高于自然种群（５８３３％）（Ｐ＜００５）;平均胎仔数（３３２）也高于自然种群（２８５）,但差异不显著（Ｐ＞００５）。     

新疆褐家鼠种群生命表及其在干旱区的生存能力分析

从2000年至今,曾于野外捕捉的褐家鼠3 837只,其中雌鼠2 685只,雄鼠1 152只,经鉴定划分为幼年组(Ⅰ)、亚成年组(Ⅱ)、成年Ⅰ组(Ⅲ)、成年Ⅱ组Ⅳ、老年组(Ⅴ)等5个年龄组,其年龄结构探讨种群数量动态,结果表明,种群中Ⅱ龄的平均生命期望值最高1.0357,其次为Ⅲ龄0.9488。该种群中1龄个体占优势地位,种群属于增长性种群,种群内禀增长率rm为0.2789/年,年周限增长率λ为1.3217,世代时间T为2.623年,种群经一世代的净增殖率R0为2.0782。     

洞庭湖区社鼠的繁殖生态

在洞庭湖区域,社鼠（Niviventer confucianus）种群主要栖息在山区和丘陵地带的林地内.总体而言,其种群雌性比基本维持在50%左右,但在季节间和年龄组间有一定的差别,雌性比在冬、春季较低,夏、秋季的雌性比都超过50%.年龄组间,雌性比最高的为幼年组66.7%,亚成年和成年组的雌性比接近50%,而老年组的雌性比为最低,为33.3%.所有雌鼠全年的怀孕率为31.1%,平均胎仔数为3.7只,繁殖指数为0.58.春、夏季怀孕率较高,冬季没有捕获到怀孕的雌鼠,仅捕获到有怀孕经历（有宫斑）的雌鼠.繁殖指数在夏、秋季维持高峰水平.雌性社鼠总的参产率为53.3%,各季间呈现从春、夏到秋逐渐增加的趋势,冬季停止怀孕.可见夏、秋季为雌鼠的繁殖高峰期.随着年龄组增长,平均胎仔数有明显增加的趋势,老年组胎仔数最高,而繁殖指数以成年组最高,说明成年组是种群中繁殖的主体.雄性社鼠的睾丸下位率全年总计为75.6%,分四季平均为86.0%,夏、秋季维持在较高水平,冬、春季稍低,低谷在春季.下位睾丸的重量与大小有明显的季节变化,呈现春、夏、秋、冬逐渐下降的规律,春季与冬季相比,有显著性差异,说明开春后,雄性社鼠在生殖潜能上已有明显变化.这些特征与雌鼠的繁殖高峰基本吻合.说明社鼠主要在春、夏、秋季繁殖,繁殖盛期在夏秋季.从不同年龄组看,幼年组个体不参与繁殖,亚成年组个体开始参与繁殖,繁殖主体是成年组个体.     

洞庭平原黄胸鼠种群年龄组的划分

根据胴体重的频次分布和每５ｇ胴体重组的鼠所对应的发育与繁殖状况,将黄胸鼠分为５个年龄组,Ⅰ,幼年组：胴体重≤３５ｇ;Ⅱ。亚成年组,３６－６５ｇ;Ⅲ。成年一组：６６－１００ｇ;Ⅳ．成年二组：１０１－１３５ｇ;Ⅴ．老年组;〉１３５ｇ。经ｔ检验,各组间的胴体重,体重,体长尾长都有显著性的差异。各年龄组间的体重与胴体重存在显著的正相关前３个年龄组的体长和尾长与胴体重之间有极显著相关性。各年龄组的雌性比变化     

安徽淮北农区三种鼠的种群数量动态与年龄结构的关系

本文对安徽省淮北农业区的黑线姬鼠、大仓鼠和黑线仓鼠的种群数量及与年龄组成变化的关系进行探讨。结果表明,其各鼠的年龄组成在每年的不同时段内的变化有一定的规律:各鼠主要繁殖群体的年龄组也是有区别的,如黑线姬鼠和黑线仓鼠主要是成年Ⅱ组,大仓鼠主要是成年Ⅰ组。如果种群中幼年组+亚成年组+成年Ⅰ组的比例高时,则当年数量就可能较高,如果种群中成年Ⅱ组和老年组的比例较高时,当年数量则低。     

用水晶体干重鉴定五趾跳鼠的种年龄

利用556只五趾跳鼠的水晶体干重作次数分配,将该鼠年龄划分成7个组进行观察：幼年组水晶体干重在55.00毫克以下,亚成年组55.01-77.50毫克（当年出生）,成年Ⅰ组55.01-87.50毫克（经过一次冬眠并参加繁殖）,成年Ⅱ组87.51-102.50毫克,成年Ⅲ组102.51-117.50毫克,成年Ⅳ组117.51-130.00毫克,老年组130.01毫克以上。据1986和1987年的观察,结果表明五趾跳鼠年龄组成季节变化明显,年度之间没有显著变化。     

蜂桶寨自然保护区中华姬鼠及社鼠肥满度的年龄和季节变化

肥满度被广泛用于动物生长状况与环境、生存、繁殖等方面的研究。为揭示横断山脉森林环境中中华姬鼠（Apodemus draco）和社鼠（Niviventer confucianus）肥满度的变化规律及影响原因,我们于2008年4~11月对四川省蜂桶寨国家级自然保护区内中华姬鼠和社鼠肥满度在各年龄组及不同季节中的变化进行了研究。结果显示,中华姬鼠肥满度在各年龄组间的差异显著,其变化趋势为老年组>成年组>亚成年组>幼年组;亚成年组及老年组肥满度在各季节间无显著差异,而在成年组则差异明显,以春季中最高。社鼠肥满度在各年龄组间无显著性差异;亚成年组肥满度在各季节间差异显著,在夏秋季中最低,同时成年组及老年组肥满度在季节间无显著差异。中华姬鼠和社鼠亚成年组、成年组及老年组肥满度与海拔无显著的线性关系。分析认为,中华姬鼠老年组个体可能在应对外界环境方面要强于幼年个体而具有最高的肥满度,成年个体肥满度的季节变化可能受食物资源季节差异和繁殖能量需求的影响;社鼠成年及老年个体能通过相应的季节性调节维持肥满度的稳定,而亚成年个体在调节方面较弱,故其肥满度在夏秋季最低。     

甘南草原高原鼢鼠年龄划分及其组成分析

建立高原鼢鼠(Eospalax baileyi)种群年龄鉴定划分标准,可为对其的监测及防控提供科学依据。研究于2015年5月、10月分别在甘南草原碌曲县采用夹捕法捕捉高原鼢鼠469只(雄鼠209只,雌鼠260只),在对样本进行逐个解剖和数据记录之后,参考其体重、体长、胴体重及毛色等,对高原鼢鼠的年龄划分标准进行研究。依据胴体重将高原鼢鼠分为6组:亚成年组(雄144 g,雌106 g),成年Ⅰ组(雄144~210 g,雌106~148 g)、成年Ⅱ组(雄211~276 g,雌149~190 g)、成年Ⅲ组(雄277~342 g,雌191~232 g)、成年Ⅳ组(雄343~408 g,雌233~274 g)和老年组(雄409 g,雌275 g)。年龄结构表显示,不同的季节和不同地理区域高原鼢鼠的种群年龄结构类型均为增长型。     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.