Life Strategies in Two Bacterivorous Marine Nematodes: Preliminary Results

Abstract. Temperature dependence of sex ratio and maximal densities of the estuarine, deposit-feeding nematodes Pellioditis marina (Rhabditidae ) and Diplolaimelloides meyli (Monhysreridae ) were investigated in vitro . Both species are characteristic for organically enriched habitats. Data from competition culture experiments with both species are integrated with information from respiration measurements at different temperatures, and from observations on the influence of temperature and bacterial density on uptake rates.
Sex ratio was significantly influenced by temperature in both species, with the highest relative numbers of males at the highest temperatures. Total numbers attained fluctuated only moderately in the 10 to 20 °C interval, but increased and decreased highly significantly at 25 °C for D. meyli and P. marina , respectively.
Respiration at temperatures from 5 °C to 30 °C was measured with nematodes from monospecific cultures using a modified Clark electrode procedure. Respiration was dependent upon temperature in the entire range for P. marina , but not for D. meyli , where only at 25 °C a clear respiratory acceleration was observed.
Feeding experiments with P. marina showed a dominant influence of bacterial density on uptake rates, with a lower but still significant temperature effect.
These data are discussed in relation to the overall life strategies of both species.     

植物生长素Q.C.对海带苗的影响

本文报道了植物生长素Ｑ．Ｃ．对海带苗的影响试验。结果表明，Ｑ．Ｃ．对海带苗的细胞分裂具有明显的促进作用，从而加速了海带配子体的生长发育。其中以０．２×１０＾－＾６（Ｖ／Ｖ）组的效果最明显，经处理３ｄ后配子体大小达１８－２０μｍ，１１ｄ后达２０－２３μｍ，并已进入了性成熟期，♀体一级突起达２２％，而对照组的大小为１６－１８μｍ，一级突起仅１％，用Ｑ．Ｃ．处理配子体阶段转化而成的幼孢子体或幼孢子体阶段     

Polychaete Fauna of Seagrass Beds (Halodule wrightii Ascherson) Along the Coast of Rio de Janeiro (Southeast Brazil)

Abstract.  The polychaete community structure from six Halodule wrightii seagrass beds along the Rio de Janeiro coast (Southeast Brazil) was investigated. Variations in species diversity, overall density and species composition in relation to sediment grain size, seagrass biomass and selected plant structural features such as root and shoot length from the study sites were analysed. Ten core samples (0.02 m²) were randomly collected from each site. Three additional samples were taken for grain size analysis of sediment. Sixty-eight species of polychaetes belonging to 24 families were found. The dominant species as well as species composition varied greatly among sites, showing that a typical polychaete community does not exist. The number of species was positively correlated with the silt-clay percent and sorting coefficient of the sediment. A positive correlation between polychaete density and plant biomass was also obtained. Multivariate analysis indicated that polychaete communities were influenced greatly by seagrass plant features: plants with longer shoots harbour mainly surface-deposit feeders such as Magelona papillicornis , whereas plants with a higher root-shoot length relation sheltered mainly suspension or interface feeders like Fabricia filamentosa . This study demonstrates that granulometric properties as well as plant architecture play an important role in structuring the polychaete community. As the community-level response can reflect changes in local seagrass beds, the structure of the polychaete community can be an important indicator for management plans and the restoration of seagrass ecosystems.     

厦门外来植物入侵风险评价指标体系的建立——以互花米草入侵风险评价为例

本文结合前人在生物入侵风险评价方面的研究成果，针对厦门市外来植物入侵现状，建立了厦门地区外来植物入侵风险评价指标体系及评价方法．该指标体系由6个一级指标，17个二级指标构成．通过文献资料分析、实地调研等手段，以厦门海域主要的入侵植物互花米草为例，评价其风险分值为85，入侵风险等级为“不可接受”．此外，本文还选取其他19种外来植物进行了风险评价与风险等级划分，结果表明。互花米草在20种外来植物中风险分值列第三，评价结果与其危害现状相符．     

Chemical forms of copper and zinc in the surficial sediments of Borollos Lake, Egypt

ＣｈｅｍｉｃａｌｆｏｒｍｓｏｆｃｏｐｐｅｒａｎｄｚｉｎｃｉｎｔｈｅｓｕｒｆｉｃｉａｌｓｅｄｉｍｅｎｔｓｏｆＢｏｒｏｌｌｏｓＬａｋｅ，Ｅｇｙｐｔ￥Ｍ．Ｓ．ＥＩ－Ｄｅｅｋ（ＮａｔｉｏｎａｌＩｎｓｔｉｔｕｔｅＯｆＯｃｅａｎｏｇｒａｐｈｙａｎｄＦｉｓｈｅｒｉ...     

长门岩岛植物群落中的山茶现状和恢复措施

报告青岛市长门岩岛植物群落中的山茶现状。指出在我国分布最北边缘的常绿阔叶植物天然山茶，因人为破坏已濒临绝境。建议成立山茶自然保护区，并提出恢复山茶植物群落的措施。     

Detection of leaf structures in close-range hyperspectral images using morphological fusion

Abstract

Close-range hyperspectral images are a promising source of information in plant biology, in particular, for in vivo study of physiological changes. In this study, we investigate how data fusion can improve the detection of leaf elements by combining pixel reflectance and morphological information. The detection of image regions associated to the leaf structures is the first step toward quantitative analysis on the physical effects that genetic manipulation, disease infections, and environmental conditions have in plants. We tested our fusion approach on Musa acuminata (banana) leaf images and compared its discriminant capability to similar techniques used in remote sensing. Experimental results demonstrate the efficiency of our fusion approach, with significant improvements over some conventional methods.     

黑龙江省能源资源开发的经济效应分析

在分析黑龙江省经济发展的周期波动与能源资源开发增长在时间序列上的耦合关系的基础上,引入资源“诅咒系数”理论来测定资源开发对区域经济发展的诅咒现象出现时间、发展走向、不同年份诅咒强度,并通过诅咒的传导机制研究剖析诅咒效应长期作用的原因。结果表明:黑龙江省资源开发与经济发展轨迹之间存在着良好的耦合关系,资源开发长期上看对经济发展存在着严重的诅咒效应;近年来资源开发的诅咒程度虽然呈持续下降态势,但诅咒的延迟性致使诅咒效应仍阻碍着黑龙江省经济的发展并还会持续较长一段时间。诅咒效应形成与财政开支不断增大,能源开发投入导致科技、教育财政支出大幅度减少存在着密切的关联,也与资源对经济发展路径锁定性密切相关。     

Socio-spatial segregation in China and migrants’ everyday life experiences: the case of Wenzhou

Although internal migration is one of the most frequently discussed aspects of China’s twenty-first century urbanization, much of the research in this area emphasizes megacities. This paper, however, focuses on Wenzhou, a Chinese city that served as a national model for the introduction of small-scale private enterprise in the 1990s. Through a survey of migrants living in the subdistrict of Shuangyu, a settlement dominated by manufacturing workers, this article argues that socio-spatial segregation research should pay more holistic attention to migrants’ use of urban space, beyond simply place of residence. Focusing on how migrants use space in several aspects of their everyday lives, this article contends that Shuangyu is socially and spatially segregated from other parts of the city. Rather than neatly incorporated into the rest of the city, migrant settlement in Wenzhou is both marginalized and independent. We thus theorize Shuangyu’s place in Wenzhou’s new socio-spatial structure as a “city within the city.”