四川金佛山藓类植物区系的研究

通过半个世纪以来对金佛山近2000号藓类植物标本的鉴定，现确定金佛山藓类植物有40科，133   属和245种(包括4亚种、9变种和1变型)。其区系成分以东亚成分为主(33．77％)，其次为温带成分   (28．57％)及热带、亚热带成分(24．68％)。文内还全面分析了金佛山藓类植物区系及我国南北8个山区藓   类植物区系之间的关系，用排序方法统计它们之间的相似性与非相似性系数，并着重就金佛山藓类植物区  系的过渡性特点作了探讨，提出在该山区与其邻近地区，存在一个苔藓植物东亚特有属的分布中心。     

乃朗高寒沼泽湿地植物群落特征与环境因子的关系

为了研究西藏高寒沼泽湿地植物群落特征和环境之间的关系,因此对乃朗湿地进行了研究。结果表明:乃朗湿地共记录到植物61种41属18科;植物科的地理成分以世界广布为主,植物属的地理成分以温带性质的分布类型主要组成;Shannon指数和水温与pH呈显著负相关,与水解性氮呈显著正相关;Simpson指数和水解性氮呈显著正相关;Pielou指数与环境因子无关;植物的地上生物量与Shannon多样性指数、水温、pH、总磷之间有相关性;依据水分梯度将乃朗湿地植物划分为旱生植物群落,湿生植物群落和沼生植物群落;含水量、盐度、水温、pH、总磷和速效磷是影响乃朗湿地植物群落分布主要环境因子。     

西藏当雄草原的植被调查与毒草治理

试验通过对西藏当雄草原试验地植被调查与喷施毒草除草剂“灭狼毒”、“灭棘豆”,发现实验地优势种群为狼毒（Stellera chamaejasme）、青海苔苹（Carex invanoviae）、羊茅（Festuca ovina）、棘豆（Oxytropis spp．）等植物种类,狼毒与棘豆两种毒草复合覆盖度可达到其中的20％～30％,毒草化比较严重;通过喷施毒草除草剂后样方调查发现植物总盖度为60％-70％,试验地植物总盖度有部分提高,可食性苔草及羊茅的种群总盖度在35％左右。狼毒相对盖度由9％～12％下降到0％,棘豆相对盖度由8％～10％下降到1％～4％,狼毒、棘豆T—text结果分别为1．91E-5、1．49E-8,均小于0．01,存在显著性差异。     

阜康绿洲土壤盐渍化与植物群落多样性的相关性分析

该文以电导、易溶性盐含量、pH作为盐渍化程度的指标 ,将阜康绿洲的土壤盐渍化程度划分为 9种类型 ,其中以强盐渍土和盐土为主 ,在纬度梯度上从南至北 ,即从洪积扇下部到沙漠按照中盐渍土—强盐渍土—盐土—强盐渍土—盐土—非盐渍土的顺序依次分布。以群落的优势种类型、灌木盖度、灌木多度、多样性等指数作为阜康绿洲荒漠植物群落的多样性指标 ,根据中国植被分类原则和系统将阜康荒漠植物群落划分为 9种类型 ,以囊果碱蓬群落—琵琶柴群落—柽柳群落或盐柴类的半灌木群落—琵琶柴群落—柽柳群落或盐柴类的半灌木群落—梭梭群落的顺序依次分布。琵琶柴群落为阜康荒漠的地带性植被 ,分布广泛 ,各种植物群落在空间上交错分布。通过相关性分析 ,结果表明 :在阜康荒漠植物群落的多度、盖度和多样性与盐渍化程度无显著相关 ,盐渍化程度的变化主要影响到植物群落组成的变化、群落类型的空间分布和演替 ,特别是盐生植物的多样性和分布     

湖北后河国家级自然保护区的生物多样性及其保护现状调研报告

湖北后河国家级自然保护区拥有丰富的生物多样性,目前已知该区有陆生脊椎动物25目74科306种,占湖北省总种数的63.5%和全国总种数的13.0%,已知该区维管植物有194科819属2 088种,占湖北省总种数的34.4%和全国总数的7.5%,属国家特有、珍稀濒危或重点保护的植物约有70余种;已知藓类植物33科90属192种和叶附生苔类植物3科7属7种,分别占全国总种数的9.8%和4.2%,该区不仅拥有丰富的动植物区系成分多样性,而且具有高度的群落物种多样性和经济类型多样性。     

中国苔草属二柱苔草亚属的系统总览及植物地理学的研究

本文对我国苔草属二柱苔草亚属Subgen．Vignea作了系统排列，并提出以下几点的看法：     1．二柱苔草亚属是苔草属中比较自然的一个类群，我国有48种、7亚种和1变种，隶属于16个 组。根据Takhtajan的世界植物区划，将它们分成4种成分，即：(1)环北方植物地区成分，占总数的 20．4％；(2)东亚植物地区成分，占总数的55.5％。实际上，只有4个分类群出现于中国-喜马拉雅森 林植物亚区，而其余的都均分布于中国-日本森林植物亚区，并且在这一亚区内有8个特有成分，占特 有成分总数的61.5％；显然，中国二柱苔草亚属在中国-日本森林植物亚区内的分化较其他地区更为强 烈；(3)伊朗—吐兰植物地区成分，占总数的16.7％；(4)印度支那植物地区成分和印度植物地区成 分，占总数的7.4％。     2．高节苔草C．thomsonii和云雾苔草C．nubigena类群是Subgen．Vignea中较为原始的种类， 它们为印度支那植物地区和印度植物地区成分。这样非但Subgen．Indocarex原始类群分布于东南亚 和马来西亚，而Subgea．Vignea的原始类群也分布于东南亚，这也是对Nelmes提出Carex起源于印度-马来西亚地区的一个佐证。     

中国四种藓类的细胞学观察

我国在苔藓植物细胞学方面的研究尚属空白。本文介绍了藓类植物染色体的研究方     法，首次报道了我国4种藓类的染色体数。研究材料均取各种藓类的幼嫩孢蒴。  本文对孢子     母细胞在减数分裂中期I的染色体进行了观察。  尖叶对齿藓Didymodon constrictus(Mitt．)     Saito．n＝14, 陕西绢藓Entodon schensianus C.Mull．n=10十lm, 尖叶走灯藓Plagiomni-     um cuspidatum(Hedw．)T．Kop．n＝6, 牛角藓Cratoneuron filicinum(Hedw．)Spruc．n＝10。    其中的前两种藓类为首次报道。并对后两种藓类的染色体数也进行了讨论。     

地形和乔木结构对热带北缘与南亚热带过渡带林下植被分布的影响

地处澜沧江下游热带北缘与南亚热带过渡带的糯扎渡自然保护区,是中国南亚热带森林生态系统类型的自然保护区。本文以糯扎渡自然保护区主要森林类型为研究对象,利用相关分析和典范对应分析（CCA）研究了地形和乔木结构对该区域林下不同生长型地表植物生长与分布格局的影响。结果表明：地形和乔木结构对热带北缘与南亚热带过渡区林下3种生长型地表植物（灌木、层间植物和草本）的生长和分布格局的影响显著,其中地形和乔木结构对灌木生长的作用大于草本,除坡度和乔木密度外,其余指标对灌木盖度或灌木高度的影响达显著水平。地形和乔木结构对林下不同生长型植被种类组成和结构的影响是不同的,按影响程度大小,影响灌木层种类组成和结构的主要因素依次为胸高断面积、树高、乔木种数和香浓维纳指数,对于层间植物,则依次为胸高断面积、树高、海拔、乔木种数和乔木盖度,对于草本层,则依次为胸高断面积、乔木种数、坡向和树高。就整体而言,乔木结构对林下植被结构和种类的影响大于与地形因子,地形因子中,仅海拔和坡向分别对林下层间植物和草本分布的影响显著,说明乔木结构是小尺度研究中影响林下水热条件的主要因子,但海拔和坡向对它们也有较大的影响。     

睡莲科的系统发育:核糖体DNA ITS区序列证据

以金鱼藻Ceratophyllum demersum为外类群,使用PAUP4.0b4A软件对睡莲科Nymphaeaceae植物7属11个代表种的ITS区序列进行了系统发育分析。采用最大简约法分析获得了3个最简约树,步长为1125,一致性指数(CI)和维持性指数(RI)值分别为0.7618和0.7214。利用3个最简约树获取严格一致树。结果表明:(1)莲属Nelumbo位于系统树的基部,自展支持率为100%,可从睡莲科中独立出来成立莲科Nelumbonaceae和莲目Nelumbonales;(2)萍蓬草属Nuphar是一单系类群,位于分支Ⅱ的基部,并和睡莲科其他属(不包括莲属)植物聚在一起构成姐妹群,故萍蓬草属仍应置于睡莲科中;(3)水盾草属Cabomba和莼菜属Brasenia聚成一小支并构成姐妹群,自展支持率为99%,说明这两属之间亲缘关系较近;(4)睡莲属和芡实属Euryale、王莲属Victoria聚成一小支并构成姐妹群,自展支持率为94%,说明三者亲缘关系较近,仍应置于睡莲科中。     

睡莲科的系统发育:核糖体DNA ITS区序列证据

以金鱼藻Ceratophyllum demersum为外类群,使用PAUP4.0b4A软件对睡莲科Nymphaeaceae植物7属11个代表种的ITS区序列进行了系统发育分析。采用最大简约法分析获得了3个最简约树,步长为1125,一致性指数(CI)和维持性指数(RI)值分别为0.7618和0.7214。利用3个最简约树获取严格一致树。结果表明:(1)莲属Nelumbo位于系统树的基部,自展支持率为100%,可从睡莲科中独立出来成立莲科Nelumbonaceae和莲目Nelumbonales;(2)萍蓬草属Nuphar是一单系类群,位于分支Ⅱ的基部,并和睡莲科其他属(不包括莲属)植物聚在一起构成姐妹群,故萍蓬草属仍应置于睡莲科中;(3)水盾草属Cabomba和莼菜属Brasenia聚成一小支并构成姐妹群,自展支持率为99%,说明这两属之间亲缘关系较近;(4)睡莲属和芡实属Euryale、王莲属Victoria聚成一小支并构成姐妹群,自展支持率为94%,说明三者亲缘关系较近,仍应置于睡莲科中。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.