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1.
The Information and Communication Technology sector is considered to be a major consumer of energy and has become an active participant in Green House Gas emissions. Lots of efforts have been devoted to make network infrastructure and network protocols power-aware and green. Among these efforts, Adaptive Link Rate (ALR) is one of the most widely discussed approaches. This survey highlights the most recent ALR approaches with a brief taxonomy and the state of the art.  相似文献   
2.
Higher order actin filament structures are necessary for cytoplasmic streaming, organelle movement, and other physiological processes. However, the mechanism by which the higher order cytoskeleton is formed in plants remains unknown. In this study, we identified a novel actin-cross-linking protein family (named CROLIN) that is well conserved only in the plant kingdom. There are six isovariants of CROLIN in the Arabidopsis genome, with CROLIN1 specifically expressed in pollen. In vitro biochemical analyses showed that CROLIN1 is a novel actin-cross-linking protein with binding and stabilizing activities. Remarkably, CROLIN1 can cross-link actin bundles into actin networks. CROLIN1 loss of function induces pollen germination and pollen tube growth hypersensitive to latrunculin B. All of these results demonstrate that CROLIN1 may play an important role in stabilizing and remodeling actin filaments by binding to and cross-linking actin filaments.  相似文献   
3.
The Qinghai-Tibet Plateau in east Asia is a unique and important permafrost environment. However, its microbiology remains largely unexplored to date. In this study, sediment samples were collected from the Qinghai-Tibet Plateau permafrost region, bacteria isolation procedures were performed 8 times, and the samples incubated at 4 degrees C for nearly 3 months. The number of colony forming units (cfu) ranged from 0 to 10(7)/(g dry soil). The quantity of culturable bacteria grew exponentially within the first few weeks, and then slowed gradually to a plateau. Phylogenetic analyses indicated that all the isolates fell into 6 categories: high G+C Gram-positive bacteria, low G+C Gram-positive bacteria, alpha-Proteobacteria, beta-Proteobacteria, gamma-Proteobacteria, and Cytophaga-Flavobacterium-Bacteroides group bacteria. The isolates belong to 19 genera, but the genera Arthrobacter and Pseudomonas were predominant. With the increase in incubation time, the isolated populations changed in terms of both species and their respective quantities. Of the 33 analyzed isolates, 9 isolates related to 8 genera might be new taxa. These results suggest that the Qinghai-Tibet Plateau permafrost region is a specific ecologic niche that accommodates an original microbial assemblage.  相似文献   
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5.
Data analysis and management represent a major challenge for gene expression studies using microarrays. Here, we compare different methods of analysis and demonstrate the utility of a personal microarray database. Gene expression during HIV infection of cell lines was studied using Affymetrix U-133 A and B chips. The data were analyzed using Affymetrix Microarray Suite and Data Mining Tool, Silicon Genetics GeneSpring, and dChip from Harvard School of Public Health. A small-scale database was established with FileMaker Pro Developer to manage and analyze the data. There was great variability among the programs in the lists of significantly changed genes constructed from the same data. Similarly choices of different parameters for normalization, comparison, and standardization greatly affected the outcome. As many probe sets on the U133 chip target the same Unigene clusters, the Unigene information can be used as an internal control to confirm and interpret the probe set results. Algorithms used for the determination of changes in gene expression require further refinement and standardization. The use of a personal database powered with Unigene information can enhance the analysis of gene expression data.  相似文献   
6.
增强的紫外线-B辐射对几种作物和品种生长的影响   总被引:28,自引:0,他引:28  
在温室条件下,以每日2.2kJ/m^2(CK)、8.82kJ/m^2(T1)和12.6kJ/m^2(T2)紫外线-B辐射(UV-B,280~320nm)剂量研究了5个黄瓜(Cucumis satious L.)品种,7个番茄(Lycopsicon esculentum Mill)品种及大豆[Glycine max(L.)Metr.]、菜豆(Phaseolus vulgaris L.)和黄河密瓜(Cucumis melo L.)的生长反应。辐射处理25d后,测定了株高(PH)、叶重(LDW)及总生物量(TDW)、叶面积(LA)、特定叶重(SLW)、上胚轴长度(EL)和番茄品种的子叶节周长(GCN)。结果表明,种间和种内差异显著。但是大多数品种及种的反应指数为负值,并呈现强度负相关效应,说明UV—B辐射抑制了它们的生长发育,但大豆的反应指数在低剂量的处理下为正值反而促进其生长。UV—B胁迫下,大多数种类的上胚轴延伸明显受阻,特定叶重增加,叶面积和生物量减少,番茄的子叶节膨大。作物对UVB辐射的种内和种间反应是作物遗传特性上的差异和对环境的适应能力不同所致。  相似文献   
7.
Summary A method was developed for in vitro regeneration of plants via somatic embryogenesis in Chorispora bungeana, an alpine plant with freeze-tolerance, using cell suspensions initiated from leaf-derived callus. Primary calli were induced from leaves of C. bungeana grown on Murashige and Skoog (MS) media supplemented with 4.0 mg l−1 gibberellic acid (GA3), 0.2 mgl−1 α-naphthaleneacetic acid (NAA) and 0.2 mgl−1 2,4-dichlorophenoxyacetic acid (2,4-D). Suspension culture was initiated by incubating the callus particulates in liquid MS medium supplemented with 1.0 mgl−1 kinetin (KT) and 0.2 mgl−1 NAA. Individual early cotyledonary-stage somatic embryos isolated from cell suspension developed into whole plants on medium containing high levels of sucrose (60 and 90 gl−1), whereas lower sucrose concentrations (0 and 30 gl−1) were inhibitory to main root development. On the MS medium with 90 gl−1 sucrose, one regenerated plant exhibited hetero-morphologic leaves, while other plants grown on different media showed a transformation from stem to root.  相似文献   
8.
Hydrogen peroxide (H2O2), an active oxygen species, is widely generated in many biological systems. The present study demonstrates that H2O2 was generated in seedling explants after the primary roots were removed, and it mediates the auxin response prior to adventitious root formation in cucumber (Cucumis sativus L. Ganfeng 8). When compared with the controls, treatment of cucumber seedling explants after primary roots removal with either 20–40 mM H2O2 or 10 μM IAA significantly increased the number of adventitious roots, and treatment with 10–50 mM H2O2 significantly increased the fresh weight of adventitious roots. The effects of H2O2 on promoting the formation and growth of adventitious roots were eliminated by 2 mM ascorbic acid, 100 U CAT or 1 μM DPI, and the effects of IAA were eliminated by 4 mM ascorbic acid, 100 U CAT or 5 μM DPI. Treatment with either 4 mM ascorbic acid or 1–5 μM DPI inhibited the formation and growth of adventitious roots, and these inhibitory effects were partly reversed by exogenous H2O2.Furthermore, a higher concentration of endogenous H2O2 was detected in seedling explants 3 h after the primary roots were removed. However, in 10 μM DPI-treated seedling explants, the concentration of endogenous H2O2 was markedly reduced by DPI. Results obtained suggest that H2O2 may function as a signaling molecule, involved in the formation and development of adventitious roots in cucumber.  相似文献   
9.
厦门凤林红树林湿地大型底栖动物群落   总被引:8,自引:0,他引:8  
为摸清厦门集美凤林红树林湿地的大型底栖动物群落结构及其多样性现状,2002年1、4、7和10月在厦门集美凤林红树林区进行大型底栖动物调查,4个季度共获得大型底栖动物42种。生物量优势种是软体动物门的珠带拟蟹守螺(Cerithideacingulata)和节肢动物门的弧边招潮(Ucaarcuata)。密度优势种是软体动物门的短拟沼螺(Assimineabrevicula)和环节动物门的沼蚓(Limnodriloidessp.)。集美凤林红树林区大型底栖动物年平均密度和年平均生物量分别为1,990ind./m2和139.0g/m2。密度的季节变化是:1月>4月>10月>7月,生物量的季节变化是1月>10月>4月>7月。聚类分析和数量分布表明,优势种珠带拟蟹守螺、短拟沼螺、弧边招潮和沼蚓的季节变化各不相同。与2002年10月深圳湾福田红树林区大型底栖动物群落的物种多样性指数平均值(0.56)比较,厦门凤林红树林区的平均值较高(2.66)。文中分析了影响大型底栖动物多样性的环境因素。  相似文献   
10.
甘肃莲花山及其邻近地区大型真菌调查初报   总被引:2,自引:0,他引:2  
本文报道了甘肃莲花山及其邻近地区的大型真茵117种,根据Ainsworth,G.C.系统(1973),隶属于60屑,26科,2亚门,其中食用菌70种,药用菌37种,毒蘑菇23种,菌根菌24种,甘肃分布新纪录50种。  相似文献   
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