封面说明

正封面照片为西南林业大学国家高原湿地研究中心陈广磊同学拍摄于玉龙雪山蓝月谷.玉龙雪山(100°4'2″—100°16'30″E、27°3'2″—27°18'57″N)位于云南省丽江市玉龙纳西族自治县,是北半球距赤道最近的现代海洋性冰川,面积455 km~2.玉龙雪山属南温带型高原季风气候区,由于河谷至     

青藏高原特有种黄绿卷毛菇的地理分布与生态环境的相关性

2008—2012年选择了中国青海、西藏、四川等22个地区,首次对青藏高原的特有真菌黄绿卷毛菇(Floccularia luteovirens)进行了全面、系统地调研,包括其地理分布、发生地的气候特征及其发生特征。研究结果表明:黄绿卷毛菇在我国的地理分布范围为纬度范围N 28°93'—37°69'、经度范围E 90°4'—102°1',主要是青藏高原地区;黄绿卷毛菇主要发生在夏秋(6—9月份),发生地的平均气温为6.2—15.9℃,平均相对湿度为41%—74%,年降水量为344—574 mm,年平均蒸发量为1393.8—2441.4mm,湿润系数为0.42—0.78。     

封面说明

正封面照片由江西师范大学地理与环境学院张宇婧于2017年8月拍摄."中国最冷小镇"呼中位于黑龙江省西北部大兴安岭地区(51°14'40″—52°25'00″N,122°39'30″—124°21'00″E),被称为"森林腹地,兴安之巅",海拔500～1000 m,四面环山,年平均气温-4.3℃,年均降水量497.7 mm,四季分明,属大陆性季风气候,素有中国偃松之乡、红毛柳之乡、黑木耳之乡的美誉.黑龙江呼中     

内蒙古鸟类新纪录——鸥鸽

<正>2014年12月2日,笔者在内蒙古自治区阿拉善盟额济纳旗进行全国第二次陆生野生动物资源调查期间,于达拉呼布镇东北7 km(101°11'51″E,42°06'38″N,海拔917 m)的农田发现约100只欧鸽Columba oenas正在休息;12月3日距此处北3 km左右的引水渠(101°11'23.96″E,42°06'47.50″N,海拔921 m)发现约150只欧鸽,多数个体在取食、饮水,少数在飞翔。2017年3月21日—5月30日,笔者在达来呼布镇多处(101°0'55.17″E,42°04'18.05″N;101°10'27.28″E,41°59'3.29″N;101°09'54.72″E,     

西双版纳尚勇自然保护区哺乳动物物种多样性

正尚勇自然保护区位于云南省西双版纳勐腊县南部,地理位置21°13'30'–21°24'48'N,101°22'48'–101°37'30'E,为1980年西双版纳自然保护区调整后新增保护区域。总面积31,184 ha,其中核心区面积18,199 ha,缓冲区面积6,736 ha,实验区面积6,249 ha(杨宇明和唐芳林,2008)。过去几十年的人为干扰使得西双版纳热带雨林破碎化程度加剧,哺乳动物多样性呈现逐渐降低的趋势(PuZhang,2001;Li et al,2009)。近年来在     

湖南壶瓶山发现白喉针尾雨燕和乌嘴柳莺

正2013年9月13日,在湖南壶瓶山国家级自然保护区(以下简称壶瓶山保护区)壶瓶山主峰(30°06'53.2″N,110°47'14.7″E,海拔2 099 m),观察到2只白喉针尾雨燕(Hirundapus caudacutus)。2013年9月23日、24日,先后又在顶坪瞭望塔上(30°02'57.6″N,110°31'22.6″E,海拔1832 m)、神景洞碑垭(30°03'34.9″N,110°31'22.6″E,海拔1711 m)共观察到8只白喉针尾雨燕。白喉针尾雨燕在中国主要分布于黑龙江、吉林、辽宁、内蒙古、河北、青海、西藏、四川、贵州、云南以及台湾(赵     

封面说明

正图片由山西省农业科学院高粱研究所张福耀研究员于2015年9月9日拍摄于内蒙古自治区赤峰市敖汉旗.敖汉旗位于燕山山脉东段努鲁尔虎山北麓,科尔沁沙地南缘,地处41°42'—43°02'N,119°30'—120°53'E.东临通辽市奈曼旗,西接朝阳市建平县,南与北票市、朝阳县相连,北与赤峰市翁牛特旗隔老哈河相望.敖汉是远近闻名的农业大县,粮食作物主要有玉米、高粱、谷子、水稻、小麦和杂豆,年产量超过6亿kg,是国家商品粮基地和内蒙古自治区产粮十强旗县之一,也是赤峰市境     

云南兽类鼠科一新纪录——南洋鼠

正中国科学院昆明动物研究所哺乳动物生态与进化学科组于2014年9月20日在云南省西双版纳傣族自治州景洪市勐龙镇勐宋村(北纬21°30'00″,东经100°29'24″,海拔1 604 m)附近的常绿阔叶林中使用sherman捕获两号疑似费氏树鼠属标本。通过形态学鉴定结合分子遗传比较,确定这两号标本为南洋鼠(Chiromyscus langbianis)。     

封面说明

正封面照片为北京林业大学自然保护区学院卜祥祺同学拍摄于乌兰哈达火山群遗址.乌兰哈达火山群遗址(113°01'—113°32'E,41°26'—41°38'N)位于内蒙古自治区察哈尔右翼后旗乌兰哈达苏木境内,地处蒙古高原南缘,地势高山平原相间,丘陵沟壑交错.该地区位于北半球中纬度地带,     

封面说明

正封面图片由中国科学院水利部水土保持研究所樊军研究员和牛小桃拍摄于中国科学院水利部水土保持研究所神木侵蚀与环境试验站.试验站位于六道沟流域(38°46'—38°51'N、110°21'—110°23'E),处于黄土高原水蚀风蚀交错带,土壤侵蚀严重,是典型的生态脆弱区,强烈的水蚀风蚀     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

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.