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221.
The European earwig, Forficula auricularia L., was surveyed using pitfall traps at 3 sites at the Hanford Reach National Monument in south central Washington State. Pitfall traps were collected weekly from April 2002 through April 2003. The earwig was consistently taken during all months of the year at a disturbed, weedy site along the Columbia River (White Bluffs Ferry site) but was rare or not collected in 2 less-disturbed shrubsteppe habitats. Highest numbers occurred during April–May, when immatures accounted for the majority of the catch; immatures reached the adult stage during mid-July, and the species is univoltine at the site. Possible reasons why earwigs have not colonized the monument’s shrubsteppe habitat include the arid climate with lack of available moisture, especially for breeding purposes, and a lack of burrow sites. La tijereta Europea, Forficula auricularia L., fue estudiada usando trampas de caída en tres sitios del Hanford Reach National Monument en el sur del estado de Washington. Se colectaron los contenidos de las trampas de caída semanalmente desde abril de 2002 hasta abril de 2003. La tijereta apareció constantemente durante todos los meses del año en un sitio perturbado de vegetación herbácea en la orilla del Río Columbia (el lugar del antiguo transbordador White Bluffs) pero su colecta fue escasa o nula en dos hábitats de estepa arbustiva menos perturbados. Los mayores números ocurrieron durante abril y mayo cuando los organismos inmaduros representaron la mayoría de los especímenes capturados; éstos alcanzaron la etapa adulta a mediados de julio y la especie es univoltina en este sitio. Posibles causas de que las tijeretas no hayan colonizado el hábitat de estepa arbustiva del Monumento podrían incluir su clima árido carente de agua disponible, especialmente para la reproducción, y una falta de sitios para madrigueras. 相似文献
222.
FL Muller S Colla E Aquilanti VE Manzo G Genovese J Lee D Eisenson R Narurkar P Deng L Nezi MA Lee B Hu J Hu E Sahin D Ong E Fletcher-Sananikone D Ho L Kwong C Brennan YA Wang L Chin RA DePinho 《Nature》2012,488(7411):337-342
Inactivation of tumour-suppressor genes by homozygous deletion is a prototypic event in the cancer genome, yet such deletions often encompass neighbouring genes. We propose that homozygous deletions in such passenger genes can expose cancer-specific therapeutic vulnerabilities when the collaterally deleted gene is a member of a functionally redundant family of genes carrying out an essential function. The glycolytic gene enolase 1 (ENO1) in the 1p36 locus is deleted in glioblastoma (GBM), which is tolerated by the expression of ENO2. Here we show that short-hairpin-RNA-mediated silencing of ENO2 selectively inhibits growth, survival and the tumorigenic potential of ENO1-deleted GBM cells, and that the enolase inhibitor phosphonoacetohydroxamate is selectively toxic to ENO1-deleted GBM cells relative to ENO1-intact GBM cells or normal astrocytes. The principle of collateral vulnerability should be applicable to other passenger-deleted genes encoding functionally redundant essential activities and provide an effective treatment strategy for cancers containing such genomic events. 相似文献
223.
Wang J Soisson SM Young K Shoop W Kodali S Galgoci A Painter R Parthasarathy G Tang YS Cummings R Ha S Dorso K Motyl M Jayasuriya H Ondeyka J Herath K Zhang C Hernandez L Allocco J Basilio A Tormo JR Genilloud O Vicente F Pelaez F Colwell L Lee SH Michael B Felcetto T Gill C Silver LL Hermes JD Bartizal K Barrett J Schmatz D Becker JW Cully D Singh SB 《Nature》2006,441(7091):358-361
Bacterial infection remains a serious threat to human lives because of emerging resistance to existing antibiotics. Although the scientific community has avidly pursued the discovery of new antibiotics that interact with new targets, these efforts have met with limited success since the early 1960s. Here we report the discovery of platensimycin, a previously unknown class of antibiotics produced by Streptomyces platensis. Platensimycin demonstrates strong, broad-spectrum Gram-positive antibacterial activity by selectively inhibiting cellular lipid biosynthesis. We show that this anti-bacterial effect is exerted through the selective targeting of beta-ketoacyl-(acyl-carrier-protein (ACP)) synthase I/II (FabF/B) in the synthetic pathway of fatty acids. Direct binding assays show that platensimycin interacts specifically with the acyl-enzyme intermediate of the target protein, and X-ray crystallographic studies reveal that a specific conformational change that occurs on acylation must take place before the inhibitor can bind. Treatment with platensimycin eradicates Staphylococcus aureus infection in mice. Because of its unique mode of action, platensimycin shows no cross-resistance to other key antibiotic-resistant strains tested, including methicillin-resistant S. aureus, vancomycin-intermediate S. aureus and vancomycin-resistant enterococci. Platensimycin is the most potent inhibitor reported for the FabF/B condensing enzymes, and is the only inhibitor of these targets that shows broad-spectrum activity, in vivo efficacy and no observed toxicity. 相似文献
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226.
Paleoproteomic study of the Iceman’s brain tissue 总被引:1,自引:1,他引:0
Frank Maixner Thorsten Overath Dennis Linke Marek Janko Gea Guerriero Bart H. J. van den Berg Bjoern Stade Petra Leidinger Christina Backes Marta Jaremek Benny Kneissl Benjamin Meder Andre Franke Eduard Egarter-Vigl Eckart Meese Andreas Schwarz Andreas Tholey Albert Zink Andreas Keller 《Cellular and molecular life sciences : CMLS》2013,70(19):3709-3722
The Tyrolean Iceman, a Copper-age ice mummy, is one of the best-studied human individuals. While the genome of the Iceman has largely been decoded, tissue-specific proteomes have not yet been investigated. We studied the proteome of two distinct brain samples using gel-based and liquid chromatography–mass spectrometry-based proteomics technologies together with a multiple-databases and -search algorithms-driven data-analysis approach. Thereby, we identified a total of 502 different proteins. Of these, 41 proteins are known to be highly abundant in brain tissue and 9 are even specifically expressed in the brain. Furthermore, we found 10 proteins related to blood and coagulation. An enrichment analysis revealed a significant accumulation of proteins related to stress response and wound healing. Together with atomic force microscope scans, indicating clustered blood cells, our data reopens former discussions about a possible injury of the Iceman’s head near the site where the tissue samples have been extracted. 相似文献
227.
NO and N2O fluxes from agricultural soils in Beijing area 总被引:2,自引:0,他引:2
LIU Xuejun Margaret WALSH JU Xiaotang ZHANG Fusuo David SCHIMEL Dennis OJIMA 《自然科学进展(英文版)》2004,14(6):489-494
Chinese agriculture represents one of the most intensively managed agroecosystems in the world. Typical nitrogen fertilization rates are more than three times those of the world' s average, resulting in dramatically accelerated nitrogen cycling in China. In this study, we have examined NO and N2O exchange in the upland agricultural systems of Beijing area. Inorganic and organic fertilizer treatments were arranged in order to evaluate their impact on the magnitude and proportion of trace gas emissions. Increasing inorganic fertilization rates showed a highly significant impact upon emissions of both NO and N2O. Organic matter amendment did not have a statistically significant impact on the N-gas fluxes examined here. Overall losses of added nitrogen by NO and N2O emission averaged 1.24% and 0.22% respectively over the range of treatments in this study. Results from our field study indicate that compared with other studies done elsewhere, emissions of reactive nitrogen from agricultural systems in Beijing area are not so large as expected before. 相似文献
228.
渤海湾盆地早第三纪构造样式可归结为5种基本类型和3个演化序列。研究结果表明,构造样式及其演化控制着烃源岩的发育,决定着油气藏的类型和展布,制约着含油气系统的范围。综合考虑含油气系统的各个要素,在渤海湾盆地可划分出6个大的含油气系统,分别位于各个坳陷中,并受坳陷的限制。进一步考虑坳陷内凸起构造单元的分割作用,可划分出13个小的含油气系统。 相似文献
229.
临清坳陷莘县凹陷油气勘探远景评价 总被引:1,自引:0,他引:1
对莘县凹陷的构造、沉积、盆地模拟及油气勘探远景等进行了深入研究。结果表明,该凹陷具有浅、中、深3个勘探层次,浅层馆陶组和沙一段以储集次生油及低成熟油气为主;中层沙二段、沙三段以自生自储型油藏为主;深层孔二段以储集高成熟油气、石炭-二迭系以煤成气为主。此地区有着极广阔的勘探远景。 相似文献
230.
神经网络在CB油田储层预测和储层厚度计算中的应用 总被引:1,自引:0,他引:1
根据CB油田的特点提出了利用神经网络进行储层预测和计算地层厚度的方法。将传统的储层预测方法与人工神经网络相结合,能较好地解决CB油田的储层预测问题。利用神经网络的非线性映射特点实现了地震特征与地层厚度之间的映射,从而可以准确地求取地层厚度。用该方法设计了2口探井,实际钻井结果表明,这种方法的预测结果准确、可靠。 相似文献