美国生物圈二号内生长在高CO2浓度下的10种植物气孔导率,蒸腾速率…

报道了美国生物圈二号内生长在高ＣＯ２浓度下（〉２２００μｍｏｌ．ｍｏｌ＾－１）４．５年后的５种热带雨林植物和５种荒漠植物气孔导率,蒸腾速率和水分利用效率的变化,结果表明,热带雨林植物在ＣＯ２浓度为３５０～４００μｍｏｌ．ｍｏｌ＾－１时的气孔导度,蒸腾速率和水分利用效率分别为：（１２７．４±６５．６）ｍｍｏｌ．ｍ＾－２．ｓ＾－１,（２．０４±０．６１）ｍｍｏｌ．ｍ＾－２．ｓ＾－１和（２．９０±０．５     

稀土化合物氯化亚鈰对人肺癌细胞PG、人胃癌细胞BGC-823的作用

 以人肺癌细胞 Ｐ Ｇ 和人胃癌细胞 Ｂ Ｇ Ｃ ８２３ 作为研究对象,利用 Ｍ Ｔ Ｔ 测定、３ Ｈ Ｔｄ Ｒ 参入、流式细胞术、软琼脂培养、 Ｎｏｒｔｈｅｒｎ ｂｌｏｔ、 Ｗ ｓｔｅｒｎ ｂｌｏｔ 等实验方法,观察了稀土化合物氯化亚鈰（ Ｃｅ Ｃｌ３）抑癌作用．结果表明, Ｃｅ Ｃｌ３ 浓度为 ００５ ｍ ｍ ｏｌ／ Ｌ,０１ ｍ ｍ ｏｌ／ Ｌ,０５ ｍ ｍ ｏｌ／ Ｌ和 １ ｍ ｍ ｏｌ／ Ｌ可抑制 Ｐ Ｇ 细胞的增殖;浓度为 ０５ ｍ ｍ ｏｌ／ Ｌ和 １ ｍ ｍ ｏｌ／ Ｌ可抑制 Ｐ Ｇ 细胞 Ｄ Ｎ Ａ 的合成,其 Ｇ１ 期细胞比例增加而 Ｓ期细胞比例减少,在软琼脂中的生长能力降低,原癌基因 ｃ ｍ ｙｃ 和 ｃ ｒａｓ 表达降低,ｐ１６ 蛋白质表达降低．而同样浓度的 Ｃｅ Ｃｌ３ 对 Ｂ Ｇ Ｃ ８２３ 细胞和正常细胞 ２ Ｂ Ｓ未见影响．提示：稀土化合物抑制肺癌细胞 Ｐ Ｇ 的增殖以及降低其恶性度的作用机制可能与一些增殖相关的原癌基因的表达和细胞周期的调控有关,其确切的机理还需进一步的研究．     

芦苇（Phragmites communis）光合作用与蒸腾作用的日进程

测定了野生芦苇（Ｐｈｒａｇｍｉｔｅｓｃｏｍｍｕｎｉｓ）光合作用、蒸腾作用及相关指标的日变化。叶片的净光合作用率在１０∶００～１５∶００间保持一个高的稳定阶段,平均为７３～９９μｍｏｌＣＯ２·ｍ－２·ｓ－１,光饱和状态下的最大值为１２７μｍｏｌＣＯ２·ｍ－２·ｓ－１,处于挺水植物的低限。蒸腾作用强度的峰值达４８ｍｍｏｌＨ２Ｏ·ｍ－２·ｓ－１。光合作用和蒸腾作用的日进程均未发生“午休”现象;相反,二者都是在正午前后强度最大。光合光量子流密度与净光合作用率、蒸腾强度、叶面传导率均存在不同程度的正相关。芦苇的光合作用强度和水分利用效率相对较低,但年生产量却较高,这是因为芦苇具有密实的叶子、有利的叶片配置结构和高的蒸腾作用强度。     

白色念珠菌摄取生物素的机制研究

本文进一步实验显示处于生物素饥饿状态的白色念珠菌摄取生物素具可饱合性和特异性。从饱合曲线测算出主动摄入生物素的半数最大初速率（１／２Ｖｍａｘ）所需生物素浓度,即Ｋｍ值为０７９±０１１（平均数±标准差,ｎ＝８）;叠氮钠（５ｍＭｏｌ／Ｌ）处理后,其Ｋｍ值增到２３９±０６４μｍＭｏｌ／Ｌ（平均数±标准差,ｎ＝３）。生物素之结构同源分子,如脱硫生物素、生物胞素、甲基酯生物素和对硝基苯酯生物素等竞争性抑制其主动摄取生物素,但是２亚氨基生物素却完全无抑制作用。在生物素摄入充足的白色念珠菌（在含２０ｎＭｏｌ／Ｌ生物素的培养基中生长）,生物素主要通过简单的弥散方式进入菌体内。由于血清中的生物素含量在ｐＭｏｌ／Ｌ到几个ｎＭｏｌ／Ｌ之间,白色念珠菌在体内可能通过主动摄取生物素机制满足其营养代谢需求。本研究为发展抗白色念珠菌新举措可能提供某种理论基础     

丹皮酚对心肌细胞自律性和延迟后除极的影响

目的与方法：采用常规玻璃微电极技术研究丹皮酚对离体心肌细胞自律性（ＡＭ）、延迟后除极（ＤＡＤ） 及触发活动（ＴＡ）的影响。结果：１．８×１０－４ｍｏｌ／Ｌ丹皮酚灌流组,肾上腺素（Ａｄｒ）的阈浓度空白对照组为（１．２８±０．５７）μｍｏｌ／Ｌ,药后为（１．５６±０．５３）μｍｏｌ／Ｌ（ｎ＝９,Ｐ＞０．０５）;用（１．８×１０－ ３） ｍｏｌ／Ｌ丹皮酚（Ｐａｅ）灌流组,Ａｄｒ 浓度由空白对照组的（１．２２ ±０．６２）μｍｏｌ／Ｌ升高到（６．２２±２．１１）μｍｏｌ／Ｌ（ｎ＝９,Ｐ＜０．０１）。１．８×１０－３ｍｏｌ／Ｌ的Ｐａｅ 能明显抑制哇巴因（Ｏｕａ）诱发的ＤＡＤ的幅值,当基本刺激周长为５００,４００,３００ 和２００ ｍｓ 时,其ＤＡＤ幅值从（５．５±２．０）ｍＶ,（７．３±２．１）ｍＶ,（８．０ ±２．４）ｍＶ和（９．２±１．９）ｍＶ减小到（３．０±１．１）ｍＶ、（３．６±１．７）ｍＶ,（４．３±２．０） ｍＶ和（５．９ ±１．６） ｍＶ,Ｐ＜０．０１。当基本刺激周长为２００ ｍｓ时,ＴＡ 数目由５．５±１．０ 降至０．７±０．３（Ｐ＜０．０１）。结论：丹皮酚能抑制心肌细胞ＡＭ、ＤＡＤ及ＴＡ,具有抗心律失常作用     

癫痫大鼠大脑皮质及海马神经元NOS的变化

给大白鼠侧脑室注射马桑内酯（Ｃｏｒｉａｒｉａ Ｌａｃｔｏｎｅ, ＣＬ）（１７５×１０－ ２ｍ ｏｌ／Ｌ２μｌ）后可诱发癫痫,用ＮＡＤＰＨｄ 组织化学方法观察大脑皮质及海马ＮＯＳ阳性神经元的变化, 结果： 大脑皮质ＮＯＳ阳性神经元数目逐渐增加, 至２ｈ 达高峰, 与生理盐水组相比差异具有非常显著性意义（Ｐ＜ ００１）, 随着ＣＬ作用时间延长ＮＯＳ反应由弱变强;海马区ＮＯＳ阳性神经元２ｈ 时才出现染色明显加深。对体外培养的大脑皮质及海马神经元用ＣＬ （２５×１０－ ５ｍ ｏｌ／Ｌ） 作用１／２ｈ、１ｈ、２ｈ、４ｈ 后ＮＯＳ阳性神经元均未见明显增加。     

SNP抑制5-HT诱导的胞内游离钙浓度升高和内钙释放

用Ｆｕｒａ － ２／ＡＭ 荧光测量技术研究了５ － 羟色胺（５－ ＨＴ） 诱导的大鼠尾动脉平滑肌细胞胞内钙升高和一氧化氮（ＮＯ） 的抑制效应。实验表明, 胞外０ｍ ｍｏｌ／ Ｌ Ｃａ２ ＋ 时胞内静息［Ｃａ２ ＋ ］ ｉ 为２０ ．２±８ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ８） 。１０μｍｏｌ／Ｌ ５－ ＨＴ 可诱导出胞内钙库释放引起的瞬态［Ｃａ２ ＋］ｉ 升高,其峰值达２４５ ．７ ±７１．６ｎｍｏｌ／ Ｌ（ｎ ＝ ６） 。１０ － ７ ｍｏｌ／Ｌ 硝普钠（ＳＮＰ） 可抑制５－ ＨＴ 诱导的［Ｃａ２ ＋］ｉ 升高,其峰值浓度降为７５．１±３５ ．９ｎｍｏｌ／Ｌ（ｎ ＝ ５） 。当细胞浴液含２．５ｍ ｍｏｌ／Ｌ Ｃａ２ ＋ 时,静息［Ｃａ２ ＋］ｉ为１１２ ．８ ±１０ ．３ｎｍｏｌ／ Ｌ（ｎ ＝ ５） , 这时１０μｍｏｌ／ Ｌ ５ － ＨＴ 可诱导［Ｃａ２ ＋ ］ ｉ 的峰值为２５２ ．３ ±８０ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,以及其后平台浓度为１４３ ．０ ±３７ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,略大于［Ｃａ２ ＋］ｉ 为１１２．８ ±１０ ．３ｎｍｏｌ／Ｌ 的静息浓度,为外钙内流引起。１０ － ７ ｍｏｌ／Ｌ ＳＮＰ 也可抑制５－ ＨＴ 诱导［Ｃａ２ ＋ ］ｉ 平台相浓度。平台浓度由１４３ ±４７     

几种荒漠植物与热带雨林植物在不同CO2浓度下光合作用对光照强度的…

使用ＬＩ－６４００便携式光合作用系统测定了美国亚利桑那州生物圈二号内５号荒漠植物（扁果菊、Ｔｒｉｘｉｓ ｃａｌｉｆｏｒｎｉｃａ、粉蓝烟草、大黍、滨黎（后两种为Ｃ４、其余为Ｃ３植物））与５种热带雨林植物、胡椒、麒麟尾、花叶万年青、牵牛（均为Ｃ３植物）的光合作用对光照强度的反应。在一系列ＣＯ２浓度（３５０￣１５００μｍｏｌ·ｍｏｌ＾－１）及不离体的前提下测定叶片光反应曲线的变化。所测植物均生长在高ＣＯ     

庐山银杏光合特性的研究

庐山山地上的银杏（ＧｉｎｋｇｏｂｉｌｏｂａＬｉｎｎ．）,其叶片的光合作用在夏季晴天有明显的午休现象,这可能与气孔关闭和光抑制有关．其光补偿点为２５μｍｏｌ（ｐｈｏｔｏｎｓ）·ｍ－２·ｓ－１左右,光饱和净光合速率为５～７μｍｏｌ（ＣＯ２）·ｍ－２·ｓ－１,表观光合量子需要量约为１９,光合作用的ＣＯ２补偿点大于１０－４,属Ｃ３型植物     

北京山区辽东栎林土壤释放CO_2的模拟实验研究

模拟北京山区辽东栎林群落,对该类型土壤释放ＣＯ２过程进行了连续３ａ的实验研究,结果表明：辽东栎林土壤呼吸强度平均为５．９２±１．３２μｍｏｌＣＯ２ｍ－２ｓ－１,在不同月份中,以８月份最高,１０月最低,依次为８月＞７月＞６月＞９月＞１０月（Ｐ＜０．０５）;１３：００为土壤日呼吸的最高峰。温度为影响土壤呼吸的主要因子,二者存在极显著相关关系（ｒ＝０．５６６８,ｐ＜０．００１,ｎ＝９４）。据３ａ观测的土壤呼吸日平均值计算得出,模拟辽东栎林土壤释放ＣＯ２的通量估计范围为１７１．５～２７５．１ｋｇＣＯ２ｈｍ－２ｄ－１,平均为２２３．３ｋｇＣＯ２ｈｍ－２ｄ－１。     

Elevated carbon dioxide is predicted to promote coexistence among competing species in a trait‐based model

Differential species responses to atmospheric CO₂ concentration (C_a) could lead to quantitative changes in competition among species and community composition, with flow‐on effects for ecosystem function. However, there has been little theoretical analysis of how elevated C_a (eC_a) will affect plant competition, or how composition of plant communities might change. Such theoretical analysis is needed for developing testable hypotheses to frame experimental research. Here, we investigated theoretically how plant competition might change under eC_a by implementing two alternative competition theories, resource use theory and resource capture theory, in a plant carbon and nitrogen cycling model. The model makes several novel predictions for the impact of eC_a on plant community composition. Using resource use theory, the model predicts that eC_a is unlikely to change species dominance in competition, but is likely to increase coexistence among species. Using resource capture theory, the model predicts that eC_a may increase community evenness. Collectively, both theories suggest that eC_a will favor coexistence and hence that species diversity should increase with eC_a. Our theoretical analysis leads to a novel hypothesis for the impact of eC_a on plant community composition. This hypothesis has potential to help guide the design and interpretation of eC_a experiments.     

A new record for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) species complex of Turkey

In this study, species complex of Turkish Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations was determined by PCR‐based DNA analysis. According to phylogenetic analyses, the B. tabaci samples have been identified within three generic groups. A major part of the samples belonged to two invasive species, either Middle East–Asia Minor 1 (MEAM1) or Mediterranean (MED). In addition to these two invasive species, several samples collected from greenhouses and cotton fields have been found to be related to Middle East–Asia Minor 2 (MEAM2), which is the first record of Turkish B. tabaci species complex.     

Molecular taxonomy: description of a cryptic Petitia species (Polychaeta: Syllidae) from the island of Mahé (Seychelles, Indian Ocean) using RAPD markers and ITS2 sequences

Petitia occulta sp. n. provides an example demonstrating that a morphologically indistinguishable species taxon can be described by molecular markers alone. Phenotypically the polychaete belongs to Petitia amphophthalma Siewing, 1956, one of the numerous meiofaunal species that have previously been regarded as cosmopolitan. Genotypically, however, by means of randomly amplified polymorphic DNA (RAPD)–polymerase chain reaction (PCR) (a DNA-fingerprinting technique) the population on the Indo-Pacific island of Mahé can be identified as a distinct taxonomic entity as: (1) genetic distance values between the Petitia from the Seychelles and from other sites (Mediterranean, Canary Islands) are relatively great; (2) differently generated cluster analyses of genetic distances produce phenograms revealing a distinctly separate clade (bootstrap 100%) for the Seychelles animals; and (3) the Seychelles animals are characterized by eight monomorphic diagnostic (i.e. autapomorphic) DNA-fragments. The RAPD procedure in this case requires the preparation of the whole organisms and, thus, no holotype is available. Instead the RAPD band-pattern with the diagnostic markers of one individual obtained with six primers, isolated DNA of one individual, and syntypes in the form of fixed, complete individuals are deposited. Species differentiation is confirmed by genomic DNA sequencing (ITS2).     

Analysis of catalase mutants underscores the essential role of CATALASE2 for plant growth and day length‐dependent oxidative signalling

Three genes encode catalase in Arabidopsis. Although the role of CAT2 in photorespiration is well established, the importance of the different catalases in other processes is less clear. Analysis of cat1, cat2, cat3, cat1 cat2, and cat2 cat3 T‐DNA mutants revealed that cat2 had the largest effect on activity in both roots and leaves. Root growth was inhibited in all cat2‐containing lines, but this inhibition was prevented by growing plants at high CO₂, suggesting that it is mainly an indirect effect of stress at the leaf level. Analysis of double mutants suggested some overlap between CAT2 and CAT3 functions in leaves and CAT1 and CAT2 in seeds. When plants had been grown to a similar developmental stage in short days or long days, equal‐time exposure to oxidative stress caused by genetic or pharmacological inhibition of catalase produced a much stronger induction of H₂O₂ marker genes in short day plants. Together, our data (a) underline the importance of CAT2 in basal H₂O₂ processing in Arabidopsis; (b) suggest that CAT1 and CAT3 are mainly “backup” or stress‐specific enzymes; and (c) establish that day length‐dependent responses to catalase deficiency are independent of the duration of oxidative stress.     

Integrative taxonomy and evolutionary history of a newly revealed spider Dysdera ninnii complex (Araneae: Dysderidae)

The spider genus Dysdera is a species‐rich clade of specialized woodlice predators, composed typically of complexes of sibling species. Here, we analyse the Dysdera ninnii complex, distinguishing three species that exhibit slight but constant differences in the morphology of their copulatory organs, and in their genetic background. We designate a neotype for D. ninnii and redescribe it. We consider Dysdera pavesii Thorell, 1873 to be a junior synonym of Dysdera ninnii Canestrini, 1868. In addition, we describe two new species ( D ysdera moravica sp. nov. and D ysdera microdonta sp. nov. ). All three species occur in the region of north‐eastern Italy, Slovenia, and north‐western Croatia. D ysdera moravica sp. nov. expanded to central Europe. The species occur allopatrically or parapatrically. All three species possess the same diploid number and X0 sex chromosome determination. In some individuals we found chromosome fusions, and such polymorphism is common in spiders with holokinetic chromosomes. The analysis of mitochondrial (cytochrome c oxidase subunit I, COI) and nuclear ribosomal (internal transcribed spacer 2, ITS2) DNA markers revealed two clades, one formed by D. ninnii and D . microdonta sp. nov. , and a second by D . moravica sp. nov. Species of the first clade are not well defined by DNA markers. We noticed only weak separation of maternally inherited COI, and even overlap of autosomally inherited ITS2 sequences. We suggest that either short speciation time, unfinished lineage sorting, or rare hybridization events caused this pattern. In one sample of D . microdonta sp. nov. we detected the coxA gene of a Rickettsia species, which is the first record of this parasitic bacteria from the spider family Dysderidae. D ysdera microdonta sp. nov. occurs at higher altitudes than D. ninnii, and their distribution ranges form a long contact zone. Remarkably, we did not record any overlap of the two distribution ranges, suggesting that the lack of a precopulatory interspecific barrier causes a loss of reproduction potential. We hypothesize that because of the unsolved interspecific barrier together with only tiny differences in morphology and COI sequences, and no differences in karyotypes and ITS2 sequences, the D. ninnii species complex is evolutionarily young. © 2014 The Linnean Society of London     

Monitoring and modeling the invasion of the fast spreading alien Senecio inaequidens DC. in an alpine region

We modeled the distribution of the South African alien Senecio inaequidens DC. in the Aosta Valley, Western Italian Alps, using data extracted from the Regional floristic database and from an intensive field survey carried out in years 2009–2010. The aims of the work were (1) to evaluate whether the species is in the introduction, colonization, or establishment stage of invasion, (2) to detect the environmental factors that drive the invasion process, and (3) to highlight the potential range of distribution of the alien species. The modeling framework was a stepwise generalized linear model (GLM), using gridded presence/absence data and environmental predictors such as topography, climate, land use, and anthropogenic and natural disturbances. GLM were fit both with and without an additional independent variable to take into account current dispersal limitations. S. inaequidens displayed a very fast spread in the Aosta Valley in the years 1990–2010. The species was positively associated with roads and rivers, southern slopes, and negatively with elevation. However, it was found at an elevation of 1600 m, showing the ability to reach higher elevations than those observed for other invasive alien species, and confirming to be pre-adapted to mountain conditions. The difference between the species distribution models, with and without dispersal constraints, suggested that the availability of seed sources still limits the potential distribution of the species, rather than the environmental variables, and that the realized regional niche differs to a great extent from the equilibrium niche. When limitations to the seed source cease (i.e., in the establishment stage), the species will likely invade large areas that are currently characterized by pastures and grasslands with native species of high agricultural importance. The invasion of S. inaequidens should therefore be considered a serious threat, due to its potential to invade mountain regions, and in particular to colonize habitats used for grazing and forage, thus leading to a high risk for cattle and human health. We discuss the relevance of the results both concerning communication with the public and to support local eradication and control activities. The inclusion of S. inaequidens in the “black list” of the regional law for the conservation of alpine flora (L.R. 45/2009) will help to transfer the information and support invasion control, in particular at medium elevations.     

Integrative taxonomic revision of Campylocia (mayflies: Ephemeroptera,Euthyplociidae)

A morphological comparison of type and non-type material of species of Campylocia, including their junior synonyms, was conducted, in addition to neighbour joining based on K2P distances and Bayesian inference analyses of 376?bp of the mitochondrial gene cytochrome oxidase I (COI) of recently collected specimens. Results revealed the lack of distinguishing characters between C. bocainensis and C. dochmia supported by the molecular analysis, where the overlap of intra- and interspecific genetic divergences suggested genetic flow among individuals. Campylocia burmeisteri is revalidated as a senior synonym of Brazilian south-eastern species C. bocainensis and C. dochmia and of E. guntheri, formerly a synonym of C. anceps. Campylocia burmeisteri is redescribed based on material from its type-locality, Nova Friburgo, Rio de Janeiro State. Two new species, C. demoulini sp. nov. and C. araca sp. nov., are described from the Amazon rain forest and a third species, C. orosi sp. nov., is described from Costa Rica. Possible cryptic species and the utility of egg morphology in the taxonomy of Campylocia are discussed for the first time for the genus. A key to the identification of adult stages of Campylocia is provided based on male genitalia and egg morphologyhttp://zoobank.org/urn:lsid:zoobank.org:pub:6779DC2C-DB98-41DF-8C52-FF97366AAF7A     

东北东部14个温带树种树干呼吸的种内种间变异

采用红外气体分析仪—局部通量测定法于2009年6 — 10月原位测定了东北东部山区14个温带森林主要组成树种的树干表面CO2通量（RW）,旨在量化种内和种间RW的差异,探索RW随树木直径和季节的变化规律,为深入理解温带森林生态系统碳循环过程、构建和校验其模型提供基础数据。测定的树种包括：散孔材阔叶树（白桦、枫桦、山杨、紫椴、五角槭）、环孔材和半环孔材阔叶树（春榆、黄菠萝、胡桃楸、蒙古栎、水曲柳）、针叶树（兴安落叶松、红松、红皮云杉、樟子松）。结果表明：树种、月份及其交互作用均显著地影响RW（P < 0.001）。测定期间平均RW波动在1.32（黄菠萝）— 3.12 μmol CO2?m-2?s-1（兴安落叶松）之间,其中环孔材和半环孔材阔叶树的平均RW高于散孔材阔叶树,而针叶树的平均RW变异较大。各个树种RW的平均值均呈单峰型季节变化模式,其中7月份最高、10月份最低。RW种内的绝对变异（标准误,SE）波动在0.11 — 0.29 μmol CO2?m-2?s-1之间,相对变异（变异系数,CV）波动在61%（红皮云杉）— 89%（白桦）之间。各个树种的RW均有随胸径（DBH）增大而增加的趋势,但两者之间的回归模型及其决定系数因树种而异。除了春榆和水曲柳之外（P > 0.05）,其它树种的RW与DBH之间的回归关系显著（P < 0.05）,表明DBH可作为某些树种RW预测和上推的一个简便实用的指标。这些结果强调了在树干呼吸能力的比较和上推估测时应充分考虑其种内种间差异的重要性。