祁连山北坡自然恢复杨桦林地植物功能型组成及其影响因素

依据生活型(乔木、藤本、灌木、半灌木、多年生禾草、多年生杂类草和一二年生草本)和水分生态型(旱生、旱中生、中生和湿生)将祁连山北坡次生杨桦林28个调查样地中的81个物种划分为18种植物功能型(Plant functiontypes,PFTs),并通过典范对应分析(CCA)方法研究植物功能型与环境因子间的关系.结果表明:自然恢复杨桦林地植物功能型主要集中在中生多年生杂类草(PFTs16)、湿生多年生杂类草(PFTs23)、旱中生多年生杂类草(PFTs9)和中生灌木(PFTs18)4个植物功能型上;乔、灌、草三层冠层特征和中生植物的大量出现,反映了群落植物生活型趋于复杂化和结构化,生态型逐渐向中生化方向演替的特点;土壤容重、有机碳和全氮含量主要影响植物的生活型分异特征,土壤含水量和林冠郁闭度是植物的水分生态型分异的主要环境因子,而坡位、坡度控制着群落植物总体分布格局的形成.图1表3参31     

The Struggle over Functional Foods: Justice and the Social Meaning of Functional Foods

The social and scientific debate overfunctional foods has two focal points: one isthe issue of the reliability andtrustworthiness of the claims connected withfunctional foods. You don't have to be asuspicious person to be skeptical vis-à-visthe rather exorbitant claims of most functionalfoods. They promise prevention against allkinds of illnesses and enhancement ofachievements like memory and vision, withouthaving been tested adequately. The second issueis the issue of the socio-cultural dimension offunctional foods and their so calleddetrimental effect on the social and normativemeanings of food, with possibly the effect thatfood in general will be treated like amedicine, with radical individualizing effects.Finally, individuals would only be allowed toeat what their gene-profile prescribes them. Inthis paper, it is argued that food is anon-neutral public good that contributesinherently to the identity of vulnerableindividuals. It should be treated in anon-neutral, but impartial way. Therefore,politics need to intervene in food markets froma justice and ethical point of view with twoaims in mind. The first aim (as an implicationof justice considerations) should be toestablish safety conditions, and to identifyand monitor food safety standards in anobjective and impartial way. Preventive medicalclaims of foods should be allowed on the basisof appropriate and objective testing methods.The second aim (as an implication of ethicalconsiderations) should be to shape conditionsfor a cohabitation of various food styles,including that of functional foods. Moreover,the cultural and symbolic meaning of food in apluralistic society requires that the differentfood styles find some modus of living andinteracting together. As long as functionalfoods comply with safety standards and respectother food styles, they should be allowed onthe market, just like any other food product.     

长江流域生态环境的意义及生态功能区段的划分

中国加入WTO之后,中国经济进一步与国际市场接轨,融入世界经济体系,机遇和挑战同在。欧美各国近年大力推行的环境标志产品认证,对第三世界商品质量设置入关的环境门槛。长江产业带作为世界最大的内河产业带和制造业基地,现在世界通行的环境管理认证体系和环境标志产品的认证,对长江流域产业尤其是外贸出口产业有长远而深刻的影响。这种认证制度,一方面对我出口商品设置了新的障碍,另一方面又将环境保护压力直接施加到企业。重视流域生态环境将从政府行为、公民压力扩展到企业行动,由于流域生态环境的负荷愈来愈重,流域生态环境的自我调节和恢复功能大幅下降,引起了日益严重的流域性生态安全问题。根据长江流域生态环境特征、不同的生态功能及存在的主要生态安全问题,将长江流域划性生态安全问题。根据长江流域生态环境特征、不同的生态功能及存在的主要生态安全问题,将长江流域划分成以下五个不同的生态功能区段,即长江源地区、金少江段（直门达至宜宾）、长江上游段（宜宾至宜昌）、长江中游段（宜昌至湖口段）、长江下游段（湖口至入海口）。针对不同区段主要的生态安全问题,应因地制宜采取相应的防范和整治措施。为保护与恢复生态功能服务。     

火灾模拟结果误差分析的函数分析法

火灾试验结果和模拟预测结果常能表达成关于时间变化的曲线,为定量描述两种随时间变化曲线间相符合的程度,引入误差分析的函数分析法。采用适合于低Mach数流修正的N-S方程描述烟气的输运过程,使用大涡模拟和Smagorinsky亚格子模型,对封闭空间内的火灾过程进行数值模拟;对其计算结果的分析表明,函数分析法能定量对模拟预测曲线与试验曲线间的差别进行描述,模是两曲线值大小的相对误差的度量,余弦是两曲线形状相似程度的度量。     

Digit ratios (2D:4D), secondary sexual characters and cell-mediated immunity in house sparrows <Emphasis Type="Italic">Passer domesticus</Emphasis>

Homeobox genes regulate development of digits, and it has been suggested that the ratio of length of second to length of fourth digit reflects such genetic effects in a sex-specific manner. We show that digit ratios in the sexually dichromatic house sparrow Passer domesticus differ between sexes, with males having higher ratios than females, and that individuals produce consistent ratios on the two feet. If Homeobox or other genes had pleiotropic effects on development of digits, behavior, and physiology of males and females, we would expect secondary sexual characters and immunity to be related to digit ratio in a sex-specific manner. The size of the visible part of the black badge in February (a secondary sexual character), but not total badge size, was positively correlated with digit ratios, suggesting that males with more male-like digit ratios had larger visible badges. Because of sex-specific effects of development on secondary sexual characters and immunity, we predicted sex-specific differences in immune response to be related to digit ratio. House sparrows with large digit ratios had weaker T cell-mediated immune response than individuals with small digit ratios, particularly in females, implying that females with more male-like digit ratios had weak immune responses. These findings are consistent with the hypothesis that early development, as reflected by digit ratios, and genetics affect the expression of adult characters that are supposedly strongly contributing to fitness.     

The centers of gravity and dynamic types of body shape of terrestrial invertebrates

In the framework of dynamic morphology theory, the centers of gravity and geometric centers of projections have been determined for the bodies of more than 182 forms of invertebrates, and these data have been used to distinguish four types of dynamic body shapes. It has been demonstrated that specific dynamic types of body shape are characteristic of individual taxa. In addition, there are a group of “transformers,” which may assume any dynamic type of shape, and a group of invertebrates with one predominant dynamic type.     

连续施用发酵猪粪对土壤中四环素抗性基因数量的影响

为了研究连续施用发酵猪粪之后,土壤中抗性基因的数量以及发酵猪粪的施用量对土壤抗性基因的影响,采用实时荧光定量PCR方法,对稻麦轮作模式下连续6年施用4.5t/hm2和9.0t/hm2发酵猪粪的土壤进行了四环素抗性基因(TRGs)的检测和定量分析.在施用发酵猪粪的土壤中能够检测到9种TRGs.施用发酵猪粪显著增加了土壤中tet G、tet L、tet B(P)、tet O、tet W的绝对数量,其中tet B(P)、tet W、tet O的绝对数量受到了施肥用量的影响;而tet Z、tet C和tet S的绝对数量则没有受到施肥的影响.上述8种TRGs在同一施肥处理的0~5cm、5~10cm以及10~20cm土壤中的相对丰度分布均无显著差异.发酵猪粪的施用也显著增加了tet G、tet L、tet B(P)和tet O的相对丰度,但是仅有tet O的相对丰度受到了施肥用量的显著影响.本研究表明,在稻麦轮作模式下,农田土壤中的TRGs数量会受到发酵猪粪中残留TRGs的影响,连续施用该粪肥会显著增加土壤中tet G、tet L、tet B(P)和tet O的绝对数量和相对丰度.因此,需要优化畜禽粪堆肥发酵工艺,以减少抗性基因在粪肥中的残留.     

寒区典型湿地浮游植物功能群季节变化及其与环境因子关系

安邦河湿地是一个典型的寒区湿地,本文运用功能群的方法对其浮游植物季节变化进行研究,并运用多元分析方法分析其与环境因子的关系.安邦河湿地共有浮游植物种8门104种,划分为14个功能群,分别是C、D、E、F、H1、J、Lo、M、MP、N、P、SN、X1和Y.其中重要功能群是C、D、E、J、Lo、N、P和Y.浮游植物的功能群组成季节变化明显,春季以功能群E和Lo生物量所占比例最大,分别为27.45%和20.49%;夏季以功能群D、J、P占优,为28.59%、18.53%和19.47%;秋季以功能群J、P为主,占39.65%和13.34%.可见,安邦河湿地浮游植物功能群的季节变化呈现为E+Lo→D+J+P→J+P的特点,反映了水环境特征:春季低水温低营养盐、夏季高水温高营养盐且水体混浊、秋季水温和营养盐均较高.运用冗余分析(RDA)分析浮游植物功能群与环境因子之间的关系,结果显示水温(WT)、无机氮(DIN)和溶解性磷酸盐(SRP)是安邦河湿地浮游植物功能群季节变化的主要环境因子.     

初始pH对厌氧环境下污泥中抗生素抗性基因行为特征的影响

污水处理厂产生大量的剩余污泥中含有丰富的抗性基因,给环境带来了潜在风险。以城市污水处理厂的剩余污泥为研究对象,在不同初始p H(对照组、初始p H=3、5、7、9、11)下观察厌氧条件下,8种抗生素浓度以及四环素类抗性基因(tet A、tet G、tet L、tet M、tet O、tet Q、tet W、tet X)、磺胺类抗性基因(sul I、sul II)和Ⅰ类整合子(int I 1)的行为特征。研究结果显示,初始p H对抗生素的降解影响较小,污泥中总抗生素的平均去除率为42%。对照组及初始p H为3、5、7、9、11下的总四环素类抗性基因分别削减0.65 log、0.96 log、0.75 log、0.62 log、0.86 log和0.98 log。不同四环素类抗性基因表现相似,在初始p H=3和初始p H=11下部分抗性基因削减较多,特别是tet A、tet G、tet L、tet O和tet X。2种磺胺类抗性基因均无削减,浓度平均上升0.18log。相关性分析显示,总抗性基因与TN、NH3-N、TP、SCOD(溶解性COD)均存在显著相关性(P0.05)。上述研究结果为污泥厌氧消化中抗生素抗性基因减量条件提供参考依据。     

A screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog Pelophylax nigromaculatus

Amphibian metamorphosis provides a wonderful model to study the thyroid hormone (TH) signaling disrupting activity of environmental chemicals, with Xenopus laevis as the most commonly used species. This study aimed to establish a rapid and sensitive screening assay based on TH-response gene expression analysis using Pelophylax nigromaculatus, a native frog species distributed widely in East Asia, especially in China. To achieve this, five candidate TH-response genes that were sensitive to T3 induction were chosen as molecular markers, and T3 induction was determined as 0.2 nmol/L T3 exposure for 48 hr. The developed assay can detect the agonistic activity of T3 with a lowest observed effective concentration of 0.001 nmol/L and EC50 at around 0.118–1.229 nmol/L, exhibiting comparable or higher sensitivity than previously reported assays. We further validated the efficiency of the developed assay by detecting the TH signaling disrupting activity of tetrabromobisphenol A (TBBPA), a known TH signaling disruptor. In accordance with previous reports, we found a weak TH agonistic activity for TBBPA in the absence of T3, whereas a TH antagonistic activity was found for TBBPA at higher concentrations in the presence of T3, showing that the P. nigromaculatus assay is effective for detecting TH signaling disrupting activity. Importantly, we observed non-monotonic dose-dependent disrupting activity of TBBPA in the presence of T3, which is difficult to detect with in vitro reporter gene assays. Overall, the developed P. nigromaculatus assay can be used to screen TH signaling disrupting activity of environmental chemicals with high sensitivity.