865 resultados para middle-class


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Development of effective therapies to eradicate persistent, slowly replicating M. tuberculosis (Mtb) represents a significant challenge to controlling the global TB epidemic. To develop such therapies, it is imperative to translate information from metabolome and proteome adaptations of persistent Mtb into the drug discovery screening platforms. To this end, reductive sulfur metabolism is genetically and pharmacologically implicated in survival, pathogenesis, and redox homeostasis of persistent Mtb. Therefore, inhibitors of this pathway are expected to serve as powerful tools in its preclinical and clinical validation as a therapeutic target for eradicating persisters. Here, we establish a first functional HTS platform for identification of APS reductase (APSR) inhibitors, a critical enzyme in the assimilation of sulfate for the biosynthesis of cysteine and other essential sulfur-containing molecules. Our HTS campaign involving 38?350 compounds led to the discovery of three distinct structural classes of APSR inhibitors. A class of bioactive compounds with known pharmacology displayed potent bactericidal activity in wild-type Mtb as well as MDR and XDR clinical isolates. Top compounds showed markedly diminished potency in a conditional Delta APSR mutant, which could be restored by complementation with Mtb APSR. Furthermore, ITC studies on representative compounds provided evidence for direct engagement of the APSR target. Finally, potent APSR inhibitors significantly decreased the cellular levels of key reduced sulfur-containing metabolites and also induced an oxidative shift in mycothiol redox potential of live Mtb, thus providing functional validation of our screening data. In summary, we have identified first-in-class inhibitors of APSR that can serve as molecular probes in unraveling the links between Mtb persistence, antibiotic tolerance, and sulfate assimilation, in addition to their potential therapeutic value.

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General propagation properties and universal curves are given for double clad single mode fibers with inner cladding index higher or lower than the outer cladding index, using the parameter: inner cladding/core radii ratio. Mode cut-off conditions are also examined for the cases. It is shown that dispersion properties largely differ from the single clad single mode fiber case, leading to large new possibilities for extension of single mode operation for large wavelength tange. Paper demonstrates that how substantially we can extend the single mode operation range by using the raised inner cladding fiber. Throughout we have applied our own computations technique to find out the eigenvalue for a given modes. Detail derivations with all trivial mathematics for eigenmode equation are derived for each case. Paper also demonstrates that there is not much use of using depressed inner cladding fiber. We have also concluded that using the large inner cladding/inner core radius we can significantly increase the single mode operation range for the large wavelength region. (C) 2015 Elsevier GmbH. All rights reserved.

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It is known that all the vector bundles of the title can be obtained by holomorphic induction from representations of a certain parabolic group on finite-dimensional inner product spaces. The representations, and the induced bundles, have composition series with irreducible factors. We write down an equivariant constant coefficient differential operator that intertwines the bundle with the direct sum of its irreducible factors. As an application, we show that in the case of the closed unit ball in C-n all homogeneous n-tuples of Cowen-Douglas operators are similar to direct sums of certain basic n-tuples. (c) 2015 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

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La Crónica de la población de Ávila es un texto de interés para el hispanomedievalismo por diversas razones: se trata del primer texto historiográfico escrito en romance en la península, contiene y da a conocer varios ejemplos de textos de diferentes géneros producidos en la península y muestra con particular nitidez la percepción que tenía de su propia clase un grupo de caballeros villanos. Recién a partir de su primera edición, en 1943, ha empezado a recibir la atención que merece, y la historia de su crítica se encuentra apenas comenzando. Se presenta aquí una revisión de las principales aproximaciones al texto que han aparecido hasta el momento.

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The experimental investigation of the thermocapillary drop migration in a vertical temperature gradient uns performed on ground. Silicon oil and pure soybean oil were used as experimental medium in drops and as continuous phases, respectively, in the present experiment. The drop migration, under the combined effects of buoyancy: and thermocapillarity, was studied for middle Reynolds numbers in order of magnitude O(10(1)). The drop migration velocities depending on drop diameters were obtained. The present experimental results show relatively small migration velocity in comparison with the one suggested by Young et nl. for linear theory of small Reynolds number. An example of flow patterns inside the drop was observed by PIV method.

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In this paper, new formulae of a class of stress intensity factors for an infinite plane with two collinear semi-infinite cracks are presented. The formulae differ from those gathered in several handbooks used all over the world. Some experiments and finite element calculations have been developed to verify the new formulae and the results have shown its reliability. Finally, the new formulae and the old are listed to show the differences between them.

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In this paper, we present an asymptotic method for the analysis of a class of strongly nonlinear oscillators, derive second-order approximate solutions to them expressed in terms of their amplitudes and phases, and obtain the equations governing the amplitudes and phases, by which the amplitudes of the corresponding limit cycles and their behaviour can be determined. As an example, we investigate the modified van der Pol oscillator and give the second-order approximate analytical solution of its limit cycle. The comparison with the numerical solutions shows that the two results agree well with each other.

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This cruise report is a summary of a field survey conducted in coastal-ocean waters of the Mid-Atlantic Bight from Nags Head, North Carolina to Cape Cod, Massachusetts and from approximately 1 nautical mile (nm) of shore seaward to the shelf break (100 m). The survey was conducted May 12 - May 21, 2006 on NOAA Ship NANCY FOSTER Cruise NF-06-06-NCCOS. Multiple indicators of ecological condition were sampled synoptically at each of 49 stations throughout the region using a random probabilistic sampling design. Samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, PAHs, PCBs, PBDEs) in sediments and target demersal biota; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, pH, sediment grain size, and organic carbon content. The overall purpose of the survey was to collect data to assess the status of ecological condition in coastal-ocean waters of the region, based on these various indicators, and to provide this information as a baseline for determining how environmental conditions may be changing with time. The results will be of value in helping to broaden our understanding of the status of ecological resources and their controlling factors, including impacts of potential ecosystem stressors, in such strategic coastal areas. (18pp.) (PDF contains 24 pages)

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Some results on fixed points related to the contractive compositions of bounded operators in a class of complete metric spaces which can be also considered as Banach's spaces are discussed through the paper. The class of composite operators under study can include, in particular, sequences of projection operators under, in general, oblique projective operators. In this paper we are concerned with composite operators which include sequences of pairs of contractive operators involving, in general, oblique projection operators. The results are generalized to sequences of, in general, nonconstant bounded closed operators which can have bounded, closed, and compact limit operators, such that the relevant composite sequences are also compact operators. It is proven that in both cases, Banach contraction principle guarantees the existence of unique fixed points under contractive conditions.

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Southend Adult Community College hosts a regular Middle Eastern and Egyptian dance class for all ages and abilities. For a performing art such as dance, learning and self-review aids such as mirrors are essential for improving technique and attainment. The Egyptian Dance course is very popular with many students enrolled. Therefore, sessions need to take place in a large hall within the college. Through inspired innovation and improvisation, the class now have an extremely useful reflective teaching aid using cameras and projectors.

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ENGLISH: Data on the size composition of catch for the years 1954-1958 have been studied to determine year class composition, age and growth of yellowfin tuna in the Eastern Tropical Pacific Ocean. Direct age determination of tropical tunas has not yet proven reliable; however, this analysis has shown that the length-frequency distributions themselves are adequate to determine year class structure and growth rates. Absolute age has been estimated by comparing the average time of spawning with the time at which age groups initially appear in the catch. SPANISH: Los datos sobre la composición del tamaño de la pesca durante los años 1954-1958 han sido estudiados con el objeto de determinar la composición de las clases anuales, la edad y el crecimiento del atún aleta amarilla en el Océano Pacífico Oriental Tropical. Las determinaciones directas de la edad de los atunes tropicales no han probado todavía ser de confianza; sin embargo, este análisis ha demostrado que las distribuciones de la frecuencia de las longitudes son adecuadas para determinar la estructura de las clases anuales y de las tasas de crecimiento. La edad absoluta ha sido estimada mediante la comparación de la época promedio de desove con la epoca en que los grupos de edades comienzan a aparecer en la pesca.

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    本书为祝贺郑哲敏先生八十华诞的学术报告会的文集,其中收录邀请报告12篇,定向征文58篇。这些论文涉及爆炸力学、岩土力学、冲击力学、材料力学性能、生物力学、物理力学、海洋工程力学、环境流体力学等几大方面,绝大多数为论文作者科研项目的最新成果。

 

会议论文
 
  洪友士;        
内禀Deborah数在破坏现象中的意义   白以龙;汪海英;        
爆炸波在混凝土夹层结构中传播特性分析   段祝平;        
海洋内波与海洋工程   李家春;程友良;范平;        
郑哲敏先生为推动我国力学和技术科学发展所作的贡献   谈庆明;        
开发深海资源的海底空间站技术   曾恒一;        
微系统动力学研究的一些新进展   赵亚溥;        
爆炸近区空气冲击波规则反射和非规则反射   周丰峻;陈叶青;任辉启;        
椭圆函数的精细积分算法   钟万勰;姚征;        
量子蒙特卡罗法的研究   孙祉伟;        
拟Hamilton系统随机平均法在活性布朗粒子动力学研究中的应用   朱位秋;邓茂林;        
二个二阶张量的各向同性标量函数的广义坐标   王文标;段祝平;        
弹性杆轴向碰撞波动问题理论分析   马炜;刘才山;黄琳;        
两个可变形结构的相互碰撞——模型与验证   余同希;阮海辉;        
结构动力计算中自由度减缩方法概述   刘彬;丁桦;梁乃刚;        
弹塑性系统动力行为探讨   杨桂通;        
SINGULARITY THEORY ON BUCKLING OF COMPRESSIBLE ELASTIC SLENDER RODS   张义同;谢宇新;        
GCr15钢超高周疲劳断口观察与裂纹起源分析   周承恩;洪友士;        
纳米尺度毛细作用学——纳米物理力学的新领域   朱如曾;        
METALLIC CELLULAR SOLIDS UNDER IMPACT LOADING   H.Zhao;S.Abdennadher;I.Elnasri;    
 
 
 
 

 

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本书收录关于力学领域的论文301篇。内容包括:回顾20世纪力学在中国的发展,描绘了2000年中国和世界在力学各主要领域的发展现状;展望力学在21世纪的发展方向,探论新世纪中可能面临的新的重大力学等问题。

前言 白以龙;杨卫;  
力学学科《学科发展与优先领域战略研究报告》   
世纪之交对力学的回顾、展望和想象 白以龙;  
计算流体力学中发展物理分析的几个问题 张涵信;李沁;宗文刚;张来平;  
非对称Riccati方程基于本征解的分析解 钟万勰;  
实验固体力学近几年的概况 伍小平;  
HIGHER-ORDER COHESIVE ELASTICITY THEORIES OF FRACTURE Anna Vainchtein;  
疲劳短裂纹群体损伤随机特征研究 洪友士;郑亮;乔宇;  
半浮区热毛细对流及其不稳定性机理 胡文瑞;唐泽眉;  
ZONAL AND CORRELATION ANALYSIS IN SWEPT SHOCK/BOUNDARY LAYER INTERACTIONS 邓学蓥;  
经典约束系统动力学的研究进展 梅凤翔;  
复杂系统的非线性动力学问题 陆启韶;  
时滞受控系统动力学研究进展 胡海岩;王在华;  
力学与航天器工程 马兴瑞;苟兴宇;周志成;  
采矿工程中的力学问题与分析 谢和平;  
CHALLENGING PROBLEMS IN FAILURE ANALYSIS OF DUAL-PHASE MATERIALS: CYCLIC MICRO-PLASTICITY AND SMALL FATIGUE CRACK TIP BEHAVIOR   
力学与国防科技 周丰峻;  
流体力学和气动热弹性力学新一代反命题的研究 刘高联;  
含灰气体近壁区流动及传热增强机制分析 王柏懿;戚隆溪;王超;江先金;  
三维定常、二维非定常分离模式及准则研究 吕志咏;