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排序方式： 共有221条查询结果，搜索用时 0 毫秒
1.
Paul M Kulesa Jessica M Teddy Miranda Smith Richard Alexander Cameron HJ Cooper Rusty Lansford Rebecca McLennan 《BMC developmental biology》2010,10(1):101
Background
Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC) as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks. 相似文献2.
J. Kaiser M. Yassin S. Prakash N. Safi M. Agami S. Lauw E. Ostrozhenkova A. Bacher F. Rohdich W. Eisenreich J. Safi A. Golan-Goldhirsh 《Phytomedicine》2007,14(4):242-249
The recently discovered non-mevalonate pathway of isoprenoid biosynthesis serves as the unique source of terpenoids in numerous pathogenic eubacteria and in apicoplast-type protozoa, most notably Plasmodium, but is absent in mammalian cells. It is therefore an attractive target for anti-infective chemotherapy. The first committed step of the non-mevalonate pathway is catalyzed by 2C-methyl-D-erythritol 4-phosphate synthase (IspC). Using photometric and NMR spectroscopic assays, we screened extracts of Mediterranean plants for inhibitors of the enzyme. Strongest inhibitory activity was found in leaf extracts of Cercis siliquastrum. 相似文献
3.
Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge. 相似文献
4.
5.
Nathalie Pettorelli Kamran Safi Woody Turner 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1643)
Assessing and predicting ecosystem responses to global environmental change and its impacts on human well-being are high priority targets for the scientific community. The potential for synergies between remote sensing science and ecology, especially satellite remote sensing and conservation biology, has been highlighted by many in the past. Yet, the two research communities have only recently begun to coordinate their agendas. Such synchronization is the key to improving the potential for satellite data effectively to support future environmental management decision-making processes. With this themed issue, we aim to illustrate how integrating remote sensing into ecological research promotes a better understanding of the mechanisms shaping current changes in biodiversity patterns and improves conservation efforts. Added benefits include fostering innovation, generating new research directions in both disciplines and the development of new satellite remote sensing products. 相似文献
6.
Background
Gene loss, inversions, translocations, and other chromosomal rearrangements vary among species, resulting in different rates of structural genome evolution. Major chromosomal rearrangements are rare in most eukaryotes, giving large regions with the same genes in the same order and orientation across species. These regions of macrosynteny have been very useful for locating homologous genes in different species and to guide the assembly of genome sequences. Previous analyses in the fungi have indicated that macrosynteny is rare; instead, comparisons across species show no synteny or only microsyntenic regions encompassing usually five or fewer genes. To test the hypothesis that chromosomal evolution is different in the fungi compared to other eukaryotes, synteny was compared between species of the major fungal taxa. 相似文献7.
Background
Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity.Methods
The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences.Results
Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data.Conclusions
The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families. 相似文献8.
9.
Guiot SR Safi B Frigon JC Mercier P Mulligan C Tremblay R Samson R 《Biotechnology and bioengineering》1995,45(5):398-405
A 450-m(3) multiplate anaerobic reactor (MPAR) has been started-up in April 1992 for treating wastewater (whey permeate and domestic wastewater) at the Nutrinor (Lactel) cheese factory in Chambord (Québec, Canada). The MPAR consists of four superimposed sections. The liquid flows upwards from one section to the next, while the gas is collected below each plate and evacuated through side-outlets. The wastewater is concurrently distributed at the bottom of the first, second, and third sections, as 50%, 33%, and 17% of the total influent stream, respectively. Granular anaerobic sludge at an initial concentration of 30 kg of volatile suspended solids (VSS) per cubic meter of reactor liquid volume was used to inoculate the reactor. Under normal operation of the factory, the chemical oxygen demand (COD) concentration of the influent ranged from 20 to 37 kg COD m(-3). The reactor organic loading rate (OLR) fluctuated between 9 and 14.7 kg COD m(-3) d(-1) for hydraulic retention times (HRT) maintained between 55 and 68 h. At the highest OLR, the MPAR showed an efficiency of 98% and 92% for soluble and total COD removal, respectively, and a methane production rate averaging around 4 m(3) m(-3) d(-1).Biomass-specific activities ranged between 7 and 51, 1.3 and 8.5, 5.3 and 12.2, 60 and 119, and 119 and 211 mmol g(-1) VSS d(-1) for glucose, propionate, acetate, formate, and hydrogen, respectively. Average equivalent-diameter of the granules was around 0.65 mm. The MPAR reactor generally showed a large capacity for solid retention with a biomass content between 32 and 37 kg VSS m(-3). (c) 1995 John Wiley & Sons, Inc. 相似文献
10.
Akram Eidi Pejman Mortazavi Khodabakhsh Behzadi Ali Haeri Rohani Shahabeddin Safi 《Biological trace element research》2013,155(2):267-275
The aim of the present study is to evaluate the protective effect of manganese chloride against carbon tetrachloride (CCl4)-induced liver injury in rats. Manganese chloride (0.001, 0.01, 0.05 and 0.1 g/kg bw) was administered intragastrically for 28 consecutive days to male CCl4-treated rats. The hepatoprotective activity was assessed using various biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT) and superoxide dismutase (SOD). Histopathological changes in the liver of different groups were also studied. Administration of CCl4 increased the serum ALT, AST, ALP and GGT but decreased SOD levels in rats. Treatment with manganese chloride significantly attenuated these changes to nearly normal levels. The animals treated with manganese chloride have shown decreased necrotic zones and hepatocellular degeneration when compared to the liver exposed to CCl4 intoxication alone. Thus, the histopathalogical studies also supported the protective effect of manganese chloride. Therefore, the results of this study suggest that manganese chloride exerts hepatoprotection via promoting antioxidative properties against CCl4-induced oxidative liver damage. 相似文献