Shrubs as a source of spatial heterogeneity—the case of Retama sphaerocarpa in Mediterranean pastures of central Spain

The processes underlying the positive effect exerted by woody species on other plant species can be grouped into a physical effect due to the canopy itself (mainly amelioration of temperature and light extremes), and an edaphic effect (nutrient enrichment). Both groups of effects are present in the savanna-like systems originated by Retama sphaerocarpa in the Iberian Peninsula. The consequences of these shrubs for the spatial heterogeneity induced in the herbaceous community are not well known. The herbaceous community was sampled by means of radial transects around 20 adult shrubs, from the canopy centre to the open areas among the shrubs, both northwards and southwards. Floristic composition, diversity and pasture mean height change both along the inside–outside gradient, and from north to south. As a nutrient enriched environment, the centre of the understorey showed the lowest species richness and evenness, and the highest standing crop. In contrast, the environmentally stressful open areas showed the highest number of species and evenness, and the lowest standing crop. This general effect is only partially due to nutrient availability, and is not homogeneous around the shrub, as open area conditions penetrate into the understorey driving the herbaceous community towards that of open areas. An individual shrub effect is also suggested by our results. Different conditions are thus provided by R. sphaerocarpa understoreys, favouring different subsets of species from the general pool, and therefore defining shrub canopies as sources of spatial heterogeneity in the whole savanna-like system.     

甘肃省啮齿动物区系及地理区划的研究

甘肃啮齿动物有87种(含7亚种),隶2目9科41属。可将甘肃划分6个省：1．陇东高原省,有28种(含l亚种),2．中部黄土高原省,有30种;3．河西走廊省,有36种,三趾心颅跳鼠和短耳沙鼠为本省特有种;4．祁连山地省,有29种,高原高山鼠和银白高山鼠为本省特有种;5．甘南高原草原省,有34种,棕背鼾和普通田鼠为本省特有种,6．陇南山地省,有34种,豪猪和巢鼠为本省特有种。     

四川短尾鼩（Anourosorex squamipes)种群动态研究

四川短尾鼩(Anourosorex squmipes)的怀孕期在每年的4、7 、9月,种群数量高峰为6月和10～11月。其种群数量的消长可分为种群潜伏期(3-4月)、盛发期(6、8、9月)、始衰期(10-11月)、凋落期(12、1、2月)以及数量间歇期(7月)和繁殖间歇期(5月)。该兽在田间是以个体群为基础的聚集型分布格局,并有高密度时低聚集和低密度时高聚集的分布特征。     

Aquaporin 0-calmodulin interaction and the effect of aquaporin 0 phosphorylation

Aquaporin 0 (AQP0), also known as major intrinsic protein of lens, is the most abundant membrane protein in the lens and it undergoes a host of C-terminally directed posttranslational modifications. The C-terminal region containing the major phosphorylation sites is a putative calmodulin-binding site, and calmodulin has been shown to regulate AQP0 water permeability. The purpose of the present study was to elucidate the role of AQP0 phosphorylation on calmodulin binding. AQP0 C-terminal peptides were synthesized with and without serine phosphorylation on S231 and S235, and the ability of these peptides to bind dansyl-labeled calmodulin and the calcium dependence of the interaction was assessed using a fluorescence binding assay. The AQP0 C-terminal phosphorylated peptides were found to have 20-50-fold lower affinities for calmodulin than the unphosphorylated peptide. Chemical cross-linking studies revealed specific sites of AQP0-calmodulin interaction that are significantly reduced by AQP0 phosphorylation. These data suggest that AQP0 C-terminal phosphorylation affects calmodulin binding in vivo and has a role in regulation of AQP0 function.     

人工饲养条件下高原鼠兔生长和发育的初步研究

本文研究了人工饲养条件下高原鼠兔的生长发育情况,并和其他种鼠兔的生长作了比较。室内高原鼠兔比野外的生长快,人工饲养的阿富汗鼠兔和北美鼠兔生长期短,成熟早。     

A MENI0RIAL T0 THE FAM0US CHINESE GE0B0TANIST PROF. ZHU YAN-CHEN

The Yunnan University, Kunming Institute of Botany, Academia Sinica, on December 5, 1980, 1ost its staff member through 30 years and more,the Senior Professor of Plant Ecology and Geo- botany,Head of Geobotanical Laboratory, (Yun- nan University),President the Yunnan Botanical Society, Editor of Acta Botanica Yunnanica, etc     

Engineered Si(1 0 0) surfaces for the gas-phase anchoring of metal β-diketonate complexes

A synthetic strategy for the covalent anchoring of nickel β-diketonate complexes on Si(1 0 0) has been examined. Engineered Si(1 0 0) surfaces were prepared by the Si-grafting of 10-undecylenic acid methyl ester followed by hydrolysis of the ester to free the carboxylic functions suited for the anchoring of the Ni complex. Bis(pentane-2,4-dionate)Ni(II) was bonded to the functionalized surface from the gas phase by the exchange of the acetylacetonate ligand with the grafted acid. The surface density of the anchored Ni complex was controlled by tuning the surface concentration of carboxylic groups adopting a mixed monolayer of undecylenic acid and 1-decene used as a spectator spacer. The nickel decorated silicon surfaces were characterized by attenuate total reflectance infrared absorption spectroscopy (ATR-IRAS) and angle resolved X-ray photoelectron spectroscopy (AR-XPS).     

应用阴茎骨形态指标划分黑腹绒鼠年龄的研究

用雄性阴茎骨近支基底高作频数分配将黑腹绒鼠指名亚种划分为5个年龄组,对各年龄组的体长、阴茎骨近支长和阴茎骨近支基底宽作t检验和F检验均有显著差异或极显著差异．表明以阴茎骨近支基底高划分黑腹绒鼠年龄组是可行的。     

The effect of spo0 mutations on the expression of spo0A- and spo0F-lacZ fusions

Summary We have constructedspo0A-lacZ andspo0F-lacZ fusions with a temperate phage vector and have investigated howspo0 gene products are involved in the expression of each of these genes. The expression ofspo0A-lacZ andspo0F-lacZ was stimulated at about the time of cessation of vegetative growth in Spo⁺ cells. This stimulation ofspo0A-lacZ was impaired by mutations in thespo0B, D, E, F orH genes but was not affected by mutations in thespo0J orK genes. Similar results were obtained with thespo0F-lacZ fusion. The effect of thespo0A mutation onspo0A-lacZ expression was characteristic: thespo0A-directed β-galactosidase activity found during vegetative growth was significantly enhanced in thespo0A mutant. This result suggests thatspo0A gene expression is autoregulated being repressed by its own gene product. Another remarkable observation was the effect of thesof-1 mutation, which is known to be aspo0A allele; it suppressed the sporulation deficiency ofspo0B, spo0D andspo0F mutants. Thespo0A-lacZ stimulation, which is impaired by any one of thesespo0 mutations, was restored by the additionalsof-1 mutation.     

醋虫(Anguilluina aceti Ehrbg)生活周期的各阶段及其受实验形态的影响

“醋虫生活周期的各个阶段及其受实验形态的影响”是贝时璋先生上世纪20年代在德国土滨根大学动物研究所读书时的博士论文,发表在1928年出版的德国《动物科学学报》第131卷,是贝时璋先生科学生涯中的第二篇学术论文,也是当时国际上关于动物胚胎发育和细胞分化研究领域的一篇重要论文。论文系统地研究了醋虫(线虫的一种)的生活周期。他通过实验形态学方法,确定了生活周期不同阶段上体细胞群和体细胞自身的潜力。在这篇论文中,贝时璋先生提出了一个当时在生物学界有重要影响的论点:稳定动物在任何生长阶段都不具备再生能力,只在进展期有细胞质的修复;细胞常数只适用于稳定期,进入细胞常数后,细胞便丧失了修复能力。贝时璋先生的这篇论文虽然撰写于75年前,今天读起来仍会被其中体现的严谨治学和创新精神所感染。贝时璋先生75年前用线虫作为他的研究材料。50年后,英国生物学家J. Sulston、H. R. Horvitz和美国生物学家S. Brenner用线虫(Caenorhaditiselegans)作为研究材料,发现了细胞凋亡(或称细胞程序性死亡)现象,并因此荣获2002年度诺贝尔生理及医学奖。现已证明:线虫是研究细胞分裂和器官发育,以及将不同的基因突变与其对器官发育的特异性影响联系起来的一种极好的模式系统。75年前,贝时璋先生就选择了这     

Seed size variation in the palm Euterpe edulis and the effects of seed predators on germination and seedling survival

Intraspecific variation in seed size is common in wild plant populations and has important consequences for the reproductive success of individual plants. Multiple, often conflicting evolutionary forces mediated by biotic as well as abiotic agents may maintain such a variation. In this paper we assessed seed size variation in a population of the threatened, commercially important palm Euterpe edulis in southeast Brazil. We investigated (i) how this variation affects the probability of attack by vertebrate and invertebrate post-dispersal seed predators, and (ii) if seed size influences the outcome of seeds damaged by beetles in terms of seed germination and early survival of seedlings. Euterpe edulis seeds varied in diameter from 8.3 to 14.1 mm. Neither insects nor rodents selected the seeds they preyed upon based on seed size. Seed germination and total, shoot and root biomasses of one-year seedlings were significantly and positively affected by seed size. Root biomass and seedling survival were negatively affected by seed damage caused by a scolytid beetle (Coccotrypes palmarum) whose adults bore into seeds to consume part of the endosperm, but do not oviposit on them. Seed size had a marginally significant effect on seedling survival. Therefore, if any advantage is accrued by E. edulis individuals producing large seeds, this is because of greater seed germination success and seedling vigor. If this is so, even a relatively narrow range of variation in seed size as observed in the E. edulis population studied may translate into differential success of individual plants.     

Morph-specific differences in reproductive success in the distylous Primula veris in a context of habitat fragmentation

Heterostylous self-incompatible plant species are particularly sensitive to habitat fragmentation and to disruption of pollination processes because of the need of intermorph cross-pollination for producing seeds. Heterostyly is characterized by sexual polymorphism through the occurrence of two (distyly) or three (tristyly) morph types that differ in floral traits (style length and anther position). We examined whether the long-styled (pin) and short-styled (thrum) morph types show differences in reproductive components and responses to habitat fragmentation in the distylous, self-incompatible perennial herb Primula veris. We documented reproductive components for pin and thrum individuals and their relationships with population size, plant density and morph ratio (pin frequency), in nine populations from Flanders (northern Belgium) located in fragmented habitats of the intensively used agricultural landscape. Seed abortion increased in small populations as a result of inbreeding depression. Fruit set increased with plant density. Seed set was positively related to pin proportion. Seed set was higher for pin than thrum in small populations, but lower in large populations. Two hypotheses can be considered to explain these morph-specific differences: a pollen transfer asymmetry, and a reproductive advantage for the partially self-compatible pin morph. Morph types appear to respond differently to habitat fragmentation constraints. A floral morph type showing partial self-compatibility may be favored in populations under pollination failure, because it can increase reproductive success and mating opportunities through intramorph crosses.     

贝时璋先生主要论著目录

[1] 贝时璋. 醋虫的生活周期. Lebenszyklus der AnguillulaacetiEhrbg. Zool. Anz., Bd. 74, 1927[2] 贝时璋. 醋虫生活周期的各阶段及其受实验形态的影响. Die Phasen des Lebenszyklus der AnguillulaacetiEhrbg. und ihre experimentellmorphologische Beeinflussung. Zeitschr. f. wiss. Zool. Bd. 131, 1928, 293~344[3] 贝时璋. 轮虫的再生实验. Regenerationsversuche an Brachionuspala(Rotatorien), Science Reports of National University Chekiang, 1933[4] 贝时璋. 细胞常数与再生的关系问题. Das problem der …     

欢迎订阅《生物物理学报》

2004年6月5日~ 8日, 北京由国际生物晶体学会、生物大分子国家重点实验室、中国科学院生物物理研究所、教育部清华大学蛋白质科学重点实验室、中国科学院中国科学技术大学结构生物学重点实验室、北京大学分子动态与稳态结构国家重点实验室联合承办的“第十届国际生物大分子结晶大会”定于2004年6月5~8日在北京召开。会议规模400人,其中,国外代表约150人,国内代表约200人。大会组织机构:1. 大会名誉主席:Rober Huber (德国),梁栋材(中国)2. 大会主席:饶子和(中国)3. 国际顾问委员会主席:R. Hilgenfeld (德国)4. 程序委员会主席:M. Pusey (…     

勇于创新 执着追求 科学巨擘 学人楷模——学习贝时璋先生治学做人的高尚品德

今年10月10日是贝时璋先生百岁华诞,也是他从事教学、科研工作80周年。1921年秋, 从上海同济医工专门学校(同济大学前身)医学预科毕业后,贝先生赴德留学,先后在福莱堡、慕尼黑和土滨根三所大学学习,研究无脊椎动物的个体发育、细胞常数和再生, 1928年3月获土滨根大学自然科学博士学位。1928年4月到1929年10月,任土滨根大学动物系助教。1929年秋, 贝时璋先生回到祖国。1930年8月,他应邀任浙江大学副教授,筹建生物学系,并确定以实验生物学为发展的主要方向,亲自执教生物系的主要课程。从此,他在中国这片大地上辛勤耕耘,从事实验细胞生物学研究…     

我国生物物理学的创始人、奠基者和科学创新的不懈战士——敬贺贝时璋教授百岁华诞

时光荏冉,前不久我们刚庆祝过贝老90岁生日和从教70周年,今年又迎来了他百岁华诞。我作为晚辈,和全国敬重他长期为我国科学教育事业奋斗的同志一道,热烈祝贺他的百岁生日!生物物理学科的创始人生命科学的发展,需要和物理学、化学、工程技术等相互结合,在交叉融合中彼此促进。这在今天已经为广大的科学工作者所接受。但在上世纪50年代却是一个争论十分激烈的问题。反对者既来自物理学家,也来自生物学家。只有少数具有远见卓识的科学家才认识到物理学和生物学不仅能够而且必需结合起来。远的有Mayer与Helmholty,后来则有Schr觟dinger,Szent …     

贝时璋先生重要活动年表

童年、少年1903年10月10日,生于浙江省镇海县(今宁波市镇海区)北乡憩桥镇。祖父是贫苦渔民,父亲是店员。1911年春,进镇海县憩桥镇进修学堂。1913年秋,进修学堂停办,进镇海县贵驷桥宝善学堂。1915年秋,进湖北汉口德华学校。1917年德华学校改为汉口第一中学。1918年冬,汉口第一中学停办。1919年春,进上海同济医工专门学校(同济大学前身)德文科。秋,升入上海同济医工专门学校医预科。留学德国八年1921年秋,同济医工专门学校医预科毕业后,赴德留学,进德国福莱堡大学。1922年秋,转德国慕尼黑大学。1923年秋,转德国土滨根大学,不但学习了生物学的…     

Influence of microclimate and species interactions on the composition of plant and invertebrate communities in alpine northern Norway

We assessed the effects of both biotic processes and abiotic factors on the community composition of vascular plant species and invertebrates at a site in northern Norway. Plant species were assigned to functional (woody versus herbaceous) and biogeographic (boreal versus alpine) groups. Invertebrate species were classified as either herbivore or predator. When species interactions and effects of the abiotic environment were partitioned, boreal species appeared to influence the distribution of alpine species and woody species the distribution of herbaceous species. Analysis of partial correlations indicated that facilitation was the dominant mode of interaction between the two pairs of plant groups. Among abiotic factors, the thermal environment probably influenced all components of the plant and invertebrate communities, except for predatory invertebrates, and wind appeared important in determining the composition of woody and alpine components of the plant community but not the herbaceous component. The composition of the boreal component of the plant community apparently influenced the composition of all invertebrate communities, except for predatory invertebrates. The composition of the woody component of the plant community influenced the composition of both herbivore and predator communities. The alpine plant-community composition influenced predatory invertebrate community composition. Woody plant community composition influenced the composition of both herbivore and predator communities. Our analytic approach, based on two kinds of structural equation models (d-separation and path analysis), provides a useful method for identifying the biotic as well as abiotic factors that influence community structure.