河南省两栖动物地理分布的聚类研究

本文对河南省现生１９ 种两栖动物的地理分布进行了聚类研究。将各种两栖动物在各动物地理省分布的有或无作为二元状态, 用联合系数来表征每两个动物地理省间两栖动物组成的相似程度, 以类平均法进行聚类;论述了河南省两栖动物地理分布的特点, 并对聚类结果与动物地理区划进行了比较。     

广东爬行动物地理分布的聚类分析

对广东省83种爬行动物的地理分布进行了聚类研究。将各种爬行动物在广东4个动物地理省(粤北、粤东、粤西、沿海)分布的有或无作为二元性状,用联合系数来表征每两个动物地理省爬行动物组成的相似程度,以类平均法进行聚类分析,结果表明爬行类在广东各动物地理省的分布受地形明显影响,论述了广东省爬行动物地理分布的特点,并对聚类结果与动物地理区划进行了比较。     

贵州各动物地理省两栖动物分布聚类的初步探讨

本文将贵州63种两栖动物在贵州五个动物地理省中有或无分布作为二元状态,用联合系数来表征两动物地理省间两栖类种类组成的相似程度,以类平均法进行聚类。聚类结果表明两硒类在贵州各动物地理省的分布受温度明显影响。文中还讨论了分布聚类与动物地理区划的关系。     

云南省两栖动物地理分布格局的聚类分析

为了量化云南省两栖动物地理分布格局及其相似性,对云南省102种两栖动物在地理小区的分布格局尺度上进行了聚类分析。建立物种有无分布的二元数据列联表,利用联合系数表示每两个地理小区内两栖动物的相似程度,以类平均法进行了聚类分析。结果表明,云南两栖动物可以归类为两大类群,相邻动物地理小区相似程度较高,南北差异显著。云南两栖动物地理分布格局与地势的阶梯变化基本一致。受地形、河流和气候的影响,分布格局的纬度变化规律不明显。在此基础上对结果与地理区划进行了对比。     

新疆北部啮齿动物地理分布的聚类研究

将新疆北部 62种啮齿动物在新疆北部 6个动物地理省中有或无分布作为二元状态 ,用联合系数来表征啮齿动物地理省间啮齿类种类组成的相似程度 ,以类平均法进行聚类。聚类结果表明啮齿类在新疆北部各动物地理省的分布主要受各种生态因子的影响。还探讨了分布聚类与动物地理省区划的关系     

新疆北部啮齿动物的地理分布的聚类研究

将新疆北部62种啮齿动物在新疆北部6个动物地理省中有或无分布作为二元状态,用联合系数来表征啮齿动物地理省间啮齿种类组成的相似程度,以类平均法进行聚类。聚类结果表明啮齿类在新疆北部各动物地理省的分布主要受各种生态因子的影响。还探讨了分布聚类与动物地理省区划的关系。     

贵州各动物地理省爬行动物分布聚类探讨

将贵州101种爬行动物在贵州五个动物地理省中有或无分布作为二元状态,用联合系数来表征两动物地理省问爬行类种类组成的相似程度,以类平均法进行聚类。聚类结果表明黔北、黔中、黔南三个动物地理省先聚为一类,再与黔东南的动物地理省聚为一类,最后与黔西动物地理省聚成一类。     

福建省两栖类物种多样性评估

地区性物种多样性评价是当前全球生物多样性研究的重要组成部分。本文采用G-F指数对福建省两栖类物种多样性进行评估,同时利用弦距离类间平均连锁的方法对福建省22个县（市）和5个两栖动物地理省进行聚类分析。结果表时：福建省各县（市）的两栖类物种多样性差异较大,其中武夷山市两栖类物种多样性的G指数,F指数和G-F指数分别为2.978,4.863和0.388。处于华中区的3个地理省（闽北、闽东和闽西地理省）首先聚类,而后与处于华南区的闽中地理省聚类,最后与闽南地理省合并。聚类结果与福建省两栖动物地理区划大体一致,但个别县（市）不太相符,作者建议将大田县划归在华中区的闽西地理省。     

山西省两栖动物区系及地理区划

山西省属古北界华北区黄土高原亚区,根据动物区系组成、地理分布和自然条件,可把山西划为3个动物地理省：1．晋北─晋西北温带半干草原动物地理省,2．晋中─晋东南温带林灌草原动物地理省,3．中条山暖温带县绿阔叶动物地理省。全省共有两栖动物13种,隶属2目5科9属。其中,古北界种3种,东洋界种7种,广布种3种     

贵州两栖动物区系及地理区划的初步研究

本文报道贵州省两栖动物63种,其中省新纪录2种,即阔褶蛙和锯腿树蛙。将贵州划分为黔西高原中山、黔北中山峡谷、黔中山原丘陵、黔东南低山丘陵盆地和黔南低山河谷五个动物地理省。认为黔南低山河谷省属于向华南区过渡的华中地带。讨论了各动物地理省的地貌、气候、两栖动物区系特征及地理替代种类。分析了各动物地理省两栖动物区系的相似性及数量关系。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV