水位和氮浓度对三江藨草幼苗生长和生物量分配的影响

以莫莫格国家级自然保护区常见植物三江藨草(Scirpus nipponicus)为研究对象,设置低(5 cm)、中(35 cm)、高(65 cm) 3个水位和低(4 mmol·L-1)、中(8 mmol·L-1)、高(12mmol·L-1) 3个氮浓度交互的室内控制实验,探究不同水位和氮浓度对湿地植物三江藨草幼苗生长及生物量分配的影响。结果表明:水位对三江藨草幼苗生长、生物量及其分配均产生显著影响(P<0.05),随着水位的升高,三江藨草株高增加,分株数、球茎数及根生物量降低,根茎、球茎、地下、地上和总生物量均呈先增加后降低的趋势;植株地上生物量分配增加,地下(包括根和球茎)生物量分配降低;氮浓度仅对植株株高、球茎数以及地下与地上部分的生物量分配有显著影响(P<0.05),对分株数及生物量的累积均无显著影响(P>0.05);综合三江藨草幼苗的生长特征和生物量累积,认为其生长的最适宜水位为35 cm;且低水位有利于植株对氮的吸收,高水位和高氮浓度限制植株的生长。     

Genetic variants of TNFα, IL10, IL1β, CTLA4 and TGFβ1 modulate the indices of alcohol-induced liver injury in East Indian population

Alcohol induced liver disease or alcoholic liver disease (ALD), a complex trait, encompasses a gamut of pathophysiological alterations in the liver due to continuous exposure to a toxic amount of alcohol (more than 80g per day). Of all chronic heavy drinkers, only 15-20% develops hepatitis or cirrhosis concomitantly or in succession. Several studies revealed that inter-individual as well as inter-ethnic genetic variation is one of the major factors that predispose to ALD. The role of genetic factors in ALD has long been sought for in ethnically distinct population groups. ALD is fast emerging as an important cause of chronic liver disease in India; even in populations such as "Bengalis" who were "culturally immune" earlier. While the genetic involvement in the pathogenesis of ALD is being sought for in different races, the complex pathophysiology of ALD as well as the knowledge of population level diversity of the relevant alcohol metabolizing and inflammatory pathways mandates the need for well designed studies of genetic factors in ethnically distinct population groups. An array of cytokines plays a critical role as mediators of injury, inflammation, fibrosis and cirrhosis in ALD. We, therefore, studied the association of polymorphisms in five relevant cytokine genes with "clinically significant" ALD in an ethnic "Bengali" population in Eastern India. Compared with "alcoholic" controls without liver disease (n=110), TNFα -238AA genotype, IL1β -511CC genotype, TGFβ1 -509CC genotype and IL10 -592AA genotype were significantly overrepresented in ALD patients (n=181; OR=2.4 and 95% CI 1.2-5.5, P(genotype)=0.042, P(allelic)=0.008; OR=2.7 and 95% CI 1.2-5.9, P(genotype)=0.018, P(allelic)=0.023; OR=4.7 and 95% CI 1.7-13.1, P(genotype)=0.003, P(allelic)=0.014; and OR=2.2 and 95% CI 1.1-4.8, P(genotype)=0.04, P(allelic)=0.039 respectively). Moreover a cumulative genetic risk analysis revealed a significant trend for developing ALD with an increase in the number of risk alleles on IL10 and TGFβ1 loci among alcoholics. The risk genotype of IL1β and TGFβ1 also influences the total bilirubin, albumin and alanine aminotransferase levels among alcoholic "Bengalis". The present study is the first case-control study from Eastern India that comprehensively identified polymorphic markers in TNFα, IL10, IL1β and TGFβ1 genes to be associated with ALD in the Bengali population, accentuating the significance of genetic factors in clinical expressions of ALD.     

长江中游地区生态系统服务平衡与城镇化的空间关系

生态系统服务与城镇化的相互作用关系研究是目前国际人地系统研究的热点和前沿领域。以长江中游地区325个县为研究单元,通过生态系统服务供需平衡评估矩阵法与城镇化相关指标分别测算了1995年、2005年、2015年生态系统服务平衡状况和城镇化水平,同时运用双变量空间自相关模型、空间计量模型探索了生态系统服务平衡与城镇化的空间关系。研究结果表明：（1）研究期间长江中游地区生态系统服务平衡状况不断恶化,而城镇化水平则持续上升;（2）生态系统服务平衡与城镇化之间存在显著负相关关系,不同区域的空间聚类模式表现出异质性;（3）添加控制变量的空间计量模型被证明能更好解释生态系统服务平衡与城镇化的空间关系,结果显示城镇化对态系统服务平衡的影响具有负外部效应,这种负外部效应在城镇化发展到一定阶段时逐渐减弱。建议,在城镇化进程中应统筹管理生态空间,尝试跨区域合作,实现生态与经济资源的共享与互补。     

Online monitoring of microcarrier based fibroblast cultivations with in situ microscopy

Animal cell culture is widely used in biotechnology for the production of many biological products. In situ microscopes acquire images directly from cell suspensions and analyze the images in matters of cell concentration, cell size distribution and cell morphology. Their applicability was already proven for yeast and suspended mammalian cell cultivations. In this work the in situ microscope was utilized to measure the level of colonization of fibroblasts on microcarrier surfaces during cultivation. For this study the murine cell line NIH-3T3 was used in combination with Cytodex 1 microcarriers. Cultivations were carried out in a 5 L stirred tank bioreactor equipped with the in situ microscope. Images were obtained sequentially with the in situ microscope over the whole cultivation time (900 images per sequence, 7.5 h per sequence on average). For the microcarrier analysis an image analysis algorithm based on a neural network was developed and implemented in the microscope analysis software.     

The stature of the self-employed and its relation with earnings and satisfaction

Taller individuals have on average a higher socio-economic status than shorter individuals. In countries where entrepreneurs have high social status, we may therefore expect that entrepreneurs are taller than wage workers. Using data from the German Socio-Economic Panel (2002–2012), we find that a 1 cm increase in an individual's height raises the probability of being self-employed (the most common proxy for entrepreneurship) versus paid employed by 0.15 percentage points. Within the self-employed, the probability of being an employer is increased by 0.10 percentage points as a result of a 1 cm increase in height, whereas this increase is 0.05 percentage points for an own-account worker. This result corroborates the higher social status of employers compared to own-account workers. We find a height premium in earnings for self-employed and paid-employed individuals: an additional 1 cm in height is associated with a 0.39% increase in hourly earnings for paid employees and a 0.52% increase for self-employed individuals. Our analysis reveals that approximately one third of the height premium in earnings is explained by differences in educational attainment. We also establish the existence of a height premium in terms of work and life satisfaction, which is more pronounced for paid employees than for self-employed individuals.     

The rich get richer: Invasion risk across North America from the aquarium pathway under climate change

Aim

To evaluate how the establishment risk of freshwater fish species from the aquarium trade will change under a climate change scenario forecast for the year 2050.

Location

North America.

Methods

In order to estimate changes in the magnitude of risk across geography and across different species in the aquarium pathway, we considered an integrated approach to modelling the probability of establishment, which simultaneously included proxies of propagule pressure, environmental variables, species traits and interactions between environment and traits. We then used the parameters of our model to predict how the risk of establishment will change under a scenario of climate change forecast for the year 2050.

Results

Our joint model performed better than submodels, suggesting that combining all components is worthwhile. The most predictive factors were precipitation, maximum temperature tolerance, maximum fish length and minimum temperature. Our joint model forecasted a 40% increase in the average risk of establishment by 2050 in the United States. In contrast to our expectations, the absolute establishment risk associated with this pathway remained very low for the entire suite of species in the aquarium trade in northern regions, such as Quebec, Canada. Instead, Florida, which has one of the highest current risks of establishment, was also forecasted to have the greatest absolute risk increase.

Main conclusions

Our methodology for risk assessment allows invasive species management strategies to consider entire suites of species at a time and to forecast establishment risk for each species and location. While the aquarium pathway is likely to become more important for the United States, the Quebec government should prioritize other pathways of introduction in its exotic invasive species strategy. Our approach can be extended to be applied to different sets of species pertaining to the same or different pathways.

     

大熊猫视力的定量化

有大量的研究提出,大熊猫具有发达的嗅觉和听觉系统但是视力很差。 虽然有些关于大熊猫视力和色觉方面的研究,但是至今我们对大熊猫的具体视力值方面的内容知之甚少。为了定量化大熊猫的视力值,我们观察并记录了8只圈养大熊猫（雌:雄=4:4）对于移动不同水平黑白相间条纹宽度的纸片的行为反应。我们发现,在测量距离为50 cm的情况下,大熊猫能够区分大约为0.46mm宽的黑白相间条纹。这个研究结果为大熊猫视网膜结构的解剖学研究提供了行为学支持,也为今后研究大熊猫的通讯和认知提供一定的参考。     

酿酒葡萄‘赤霞珠’VvbHLH 93基因的克隆及分析北大核心CSCD

bHLH93转录因子参与调节植物的生长发育、应对各种胁迫等多种生理过程,该研究以酿酒葡萄‘赤霞珠’为试验材料,采用RT-PCR方法克隆葡萄VvbHLH 93基因全长,并进行生物信息学分析;用qRT-PCR法分析bHLH93在不同组织和果实不同发育时期的表达量,为进一步探索VvbHLH 93基因的功能及其机制奠定基础。结果表明:(1)成功克隆获得葡萄VvbHLH 93,该基因cDNA全长为1319 bp,开放阅读框长度为939 bp,编码312个氨基酸,相对分子量为35.18 kD,理论等电点为4.68,无信号肽和跨膜域,属于bHLH转录因子家族。(2)葡萄bHLH93蛋白与荷花的亲缘关系较近;VvbHLH93蛋白的C端为酸性结构区,富含丝氨酸、苏氨酸磷酸化位点;VvbHLH 93基因的启动子含有光响应元件和低温、干旱、赤霉素等应答元件。(3)qRT-PCR分析表明,VvbHLH 93在‘赤霞珠’中的表达具有组织特异性,在叶片中基本不表达,在茎中的表达量最高;随着赤霞珠葡萄果实的发育成熟,VvbHLH93相对表达量不断降低,到幼果期(直径>2 mm)后第5周开始相对表达量基本为0,总体呈现降低的变化趋势;与对照相比,在低温胁迫、盐胁迫、高温胁迫及充分灌溉胁迫下VvbHLH 93表达量显著降低。研究推测,VvbHLH 93基因可能是葡萄抗逆胁迫的负转录因子。     

干旱内陆河流域生态安全格局的构建及优化——以石羊河流域为例

生态安全格局识别及构建是保障干旱区生态安全、实现可持续发展的基本空间途径。石羊河流域是典型的干旱内陆河流域,其生态环境极为脆弱、敏感。基于石羊河流域生态本底特征,选取并定量评估水资源、生物多样性、水土保持和沙漠化4种生态系统服务,识别生态源地;以建筑物指数和植被净初级生产力为阻力因子,应用加权叠加法构建基本阻力面,并运用最小累积阻力模型及水文分析法识别生态廊道和生态功能节点,进行生态安全格局构建及优化。结果表明:(1) 2005—2015年,石羊河流域生态源地增加,生态环境质量趋于好转,特别是下游民勤绿洲区及上游祁连山区源地面积增加明显。2005、2010、2015年生态源地面积占流域总面积的比重分别为16.7%、14.7%、19.8%;(2) 2005—2015年,生态廊道明显增加,流域整体生态安全格局网络趋向复杂完善。2005年和2010年提取的生态节点都为36个,2015年的生态节点为35个,生态廊道从2005年的23条增加到2015年47条,部分潜在廊道发展演化为廊道;(3)基于2005—2015年生态安全格局分析,构建了以"二带区、三绿洲、五廊道、多中心"为核心的"绿洲廊道功...     

Zonation of spiders (Araneae) and carabid beetles (Coleoptera: Carabidae) in island salt marshes at the North Sea coast

The specific communities of spiders and carabid beetles of island salt marsh habitats of the East Frisian Island chain at the German North Sea coast were investigated. During the vegetation periods of 1997 and 1998 three pitfall trapping transects were installed on the islands of Borkum and Wangerooge. Within the salt marshes, transects extended from 0 m to 175 m. Elevation gradients varied between 10 cm and 232 cm above MHT (mean high tide). On Borkum, 35 traps were exposed in two transects, on Wangerooge 25 traps were placed in one transect. Three to five elevations above MHT were investigated per transect, each one with five traps. Highest species numbers were recorded in the higher elevated salt marshes. In contrast, highest activity values were noticed in the medium elevated salt marshes. Within both groups, spiders and carabids, four communities were distinguished by indirect gradient analysis. Indicator species were assigned to the different communities that were mainly assorted to different elevations of the salt marshes. Thus, the communities of both taxa corresponded well to the vegetational formations. The importance of sea level rise for structuring the communities of salt marsh arthropods is discussed. Overall, still great uncertainties exist on how arthropod communities and salt marshes themselves will develop.