1000 resultados para 11150004 M6


Relevância:

20.00% 20.00%

Publicador:

Resumo:

O presente trabalho tem como objetivo o estudo de 3 dos mais significativos sismos instrumentais ocorridos na faixa S. Miguel-Glória, Açores: o de 8 de Maio de 1939 e os de 5 e 7 de Abril de 2007. A investigação envolveu a concepção e desenvolvimento de um método que permite recuperar os movimentos reais do solo em formato digital a partir de sismogramas antigos. Os resultados obtidos para o sismo de 1939 relocalizam o evento numa posição mais próxima da fronteira de placas e com mecanismo também mais próximo da generalidade dos eventos estudados. O estudo da fonte dos sismos de 2007 reforçam o mecanismo padrão da zona.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper compares the performances of two different optimisation techniques for solving inverse problems; the first one deals with the Hierarchical Asynchronous Parallel Evolutionary Algorithms software (HAPEA) and the second is implemented with a game strategy named Nash-EA. The HAPEA software is based on a hierarchical topology and asynchronous parallel computation. The Nash-EA methodology is introduced as a distributed virtual game and consists of splitting the wing design variables - aerofoil sections - supervised by players optimising their own strategy. The HAPEA and Nash-EA software methodologies are applied to a single objective aerodynamic ONERA M6 wing reconstruction. Numerical results from the two approaches are compared in terms of the quality of model and computational expense and demonstrate the superiority of the distributed Nash-EA methodology in a parallel environment for a similar design quality.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

AIM To investigate the number of hypertensive patients, the optometrist is able to identify by routinely taking blood pressure (BP) measurements for patients in "at -risk" groups, and to sample patients' opinions regarding in -office BP measurement. Many of the optometrists in Saudi Arabia practice in optical stores. These stores are wide spread, easily accessible and seldom need appointments. The expanding role of the optometrist as a primary health care provider (PHCP) and the increasing global prevalence of hypertension, highlight the need for an integrated approach towards detecting and monitoring hypertension. METHODS Automated BP measurements were made twice (during the same session) at five selected optometry practices using a validated BP monitor (Omron M6) to assess the number of patients with high BP (HBP) - in at -risk groups -visiting the eye clinic routinely. Prior to data collection, practitioners underwent a two-day training workshop by a cardiologist on hypertension and how to obtain accurate BP readings. A protocol for BP measurement was distributed and retained in all participating clinics. The general attitude towards cardiovascular health of 480 patients aged 37.2 (依12.4)y and their opinion towards in-office BP measurement was assessed using a self -administered questionnaire. RESULTS A response rate of 83.6% was obtained for the survey. Ninety -three of the 443 patients (21.0% ) tested for BP in this study had HBP. Of these, (62 subjects) 67.7% were unaware of their HBP status. Thirty of the 105 subjects (28.6%) who had previously been diagnosed with HBP, still had HBP at the time of this study, and only 22 (73.3%) of these patients were on medication. Also, only 25% of the diagnosed hypertensive patients owned a BP monitor. CONCLUSION Taking BP measurements in optometry practices, we were able to identify one previously undiagnosed patient with HBP for every 8 adults tested. We also identified 30 of 105 previously diagnosed patients whose BP was poorly controlled, twenty-two of whom were on medication. The patients who participated in this study were positively disposed toward the routine measurement of BP by optometrists.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents observations of SiO maser emission from 161 Mira variables distributed over a wide range of intrinsic parameters like spectral type, bolometric magnitude and amplitude of pulsation. The observations were made at 86.243 GHz, using the 10.4 m millimeter-wave telescope of the Raman Research Institute at Bangalore, India. These are the first observations made using this telescope. From these observations, we have established that the maser emission is restricted to Miras having mean spectral types between M6 and M10. The infrared period-luminosity relation for Mira variables is used to calculate their distances and hence estimate their maser luminosities from the observed fluxes. The maser luminosity is found to be correlated with the bolometric magnitude of the Mira variable. On an H-R diagram, the masing Mira variables are shown to lie in a region distinct from that for the non-masing ones.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Phase variation (random ON/OFF switching) of gene expression is a common feature of host-adapted pathogenic bacteria. Phase variably expressed N-6-adenine DNA methyltransferases (Mod) alter global methylation patterns resulting in changes in gene expression. These systems constitute phase variable regulons called phasevarions. Neisseria meningitidis phasevarions regulate genes including virulence factors and vaccine candidates, and alter phenotypes including antibiotic resistance. The target site recognized by these Type III N-6-adenine DNA methyltransferases is not known. Single molecule, real-time (SMRT) methylome analysis was used to identify the recognition site for three key N. meningitidis methyltransferases: ModA11 (exemplified by M.NmeMC58I) (5'-CGY(m6)AG-3'), ModA12 (exemplified by M.Nme77I, M.Nme18I and M.Nme579II) (5'-AC(m6)ACC-3') and ModD1 (exemplified by M.Nme579I) (5'-CC(m6)AGC-3'). Restriction inhibition assays and mutagenesis confirmed the SMRT methylome analysis. The ModA11 site is complex and atypical and is dependent on the type of pyrimidine at the central position, in combination with the bases flanking the core recognition sequence 5'-CGY(m6)AG-3'. The observed efficiency of methylation in the modA11 strain (MC58) genome ranged from 4.6% at 5'-GCGC(m6)AGG-3' sites, to 100% at 5'-ACGT(m6)AGG-3' sites. Analysis of the distribution of modified sites in the respective genomes shows many cases of association with intergenic regions of genes with altered expression due to phasevarion switching.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper, an implicit scheme is presented for a meshless compressible Euler solver based on the Least Square Kinetic Upwind Method (LSKUM). The Jameson and Yoon's split flux Jacobians formulation is very popular in finite volume methodology, which leads to a scalar diagonal dominant matrix for an efficient implicit procedure (Jameson & Yoon, 1987). However, this approach leads to a block diagonal matrix when applied to the LSKUM meshless method. The above split flux Jacobian formulation, along with a matrix-free approach, has been adopted to obtain a diagonally dominant, robust and cheap implicit time integration scheme. The efficacy of the scheme is demonstrated by computing 2D flow past a NACA 0012 airfoil under subsonic, transonic and supersonic flow conditions. The results obtained are compared with available experiments and other reliable computational fluid dynamics (CFD) results. The present implicit formulation shows good convergence acceleration over the RK4 explicit procedure. Further, the accuracy and robustness of the scheme in 3D is demonstrated by computing the flow past an ONERA M6 wing and a clipped delta wing with aileron deflection. The computed results show good agreement with wind tunnel experiments and other CFD computations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

加卸载响应比(LURR)理论是~种前景很好的中期地震预测方法,通常在强烈地震发生前的数月至l~2年I.URR出现高值,因而I。URR可以作为强烈天然地震的前兆,用此方法曾经成功地预测过Northridge地震(1 994年1月17日,M6.7,美国加州),Nanto地震(1 996年9月11日,M6.6,日本)及不少发生在中国的天然地震。用房山煤矿1 992年8月至1993年7月的微震资料,计算了全年内7组M>2.1矿震前的加卸载响应比γ值,其中5组矿震前γ值均明显大于l(γ≥2 9)。以上结果表明,加卸载响应比理论有可能用于矿震的预测。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Elkhorn Slough was first exposed to direct tidal forcing from the waters of Monterey Bay with the construction of Moss Landing Harbor in 1946. Elkhorn Slough is located mid-way between Santa Cruz and Monterey close to the head of Monterey Submarine Canyon. It follows a 10 km circuitous path inland from its entrance at Moss Landing Harbor. Today, Elkhorn Slough is a habitat and sanctuary for a wide variety of marine mammals, fish, and seabirds. The Slough also serves as a sink and pathway for various nutrients and pollutants. These attributes are directly or indirectly affected by its circulation and physical properties. Currents, tides and physical properties of Elkhorn Slough have been observed on an irregular basis since 1970. Based on these observations, the physical characteristics of Elkhorn Slough are examined and summarized. Elkhorn Slough is an ebb-dominated estuary and, as a result, the rise and fall of the tides is asymmetric. The fact that lower low water always follows higher high water and the tidal asymmetry produces ebb currents that are stronger than flooding currents. The presence of extensive mud flats and Salicornia marsh contribute to tidal distortion. Tidal distortion also produces several shallow water constituents including the M3, M4, and M6 overtides and the 2MK3 and MK3 compound tides. Tidal elevations and currents are approximately in quadrature; thus, the tides in Elkhorn Slough have some of the characters of a standing wave system. The temperature and salinity of lower Elkhorn Slough waters reflect, to a large extent, the influence of Monterey Bay waters, whereas the temperature and salinity of the waters of the upper Slough (>5 km from the mouth) are more sensitive to local processes. During the summer, temperature and salinity are higher in the upper slough due to local heating and evaporation. Maximum tidal currents in Elkhorn Slough have increased from approximately 75 to 120 cm/s over the past 30 years. This increase in current speed is primarily due to the change in tidal prism which has increased from approximately 2.5 to 6.2 x 106 m3 between 1956 and 1993. The increase in tidal prism is the result of both 3 rapid man-made changes to the Slough, and the continuing process of tidal erosion. Because of the increase in the tidal prism, the currents in Elkhorn Slough exhibit positive feedback, a process with uncertain consequences. [PDF contains 55 pages]

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Entre 06/08/11 e 25/02/12 foram obtidas séries temporais contínuas de intensidade e direção das correntes e intensidade do eco ao longo de toda a coluna dágua, e medições, de temperatura e pressão, próximas ao fundo, na região adjacente ao canal de acesso à baía de Sepetiba (230'16.5"S e 4359'29.4"W, profundidade local de aproximadamente 25 m) através da utilização de um perfilador acústico ADCP (Acoustic Doppler Current Profiler), modelo WorkHorse BroadBand Sentinel (600 kHz, Teledyne-RDI). A partir dos dados adquiridos, observou-se a existência de correntes intensas próximo ao fundo (até 1,02 m/s), principalmente durante os períodos de enchente sob condições de sizígia, que são fortemente influenciadas pela orientação do canal de navegação. A análise das séries temporais das componentes da velocidade mostraram, em conformidade ao relatado por alguns autores, que esta é uma baía cuja circulação é fortemente influenciada pela dinâmica da maré sendo M2, M4, M6 e M8 as principais componentes harmônicas que atuam no sistema. Além disso, observou-se significativa assimetria da maré, sendo os períodos de enchente consideravelmente mais curtos e associados às correntes mais intensas, o que permite concluir que no setor investigado da baía de Sepetiba há dominância de enchente. Outra característica interessante da área de estudo relaciona-se à observação de que ventos intensos de S-SO são responsáveis pelo empilhamento de água no interior da baía, sendo que altura do nível da superfície da água apresenta relação direta com as variações da pressão atmosférica local. Em diversos períodos, quando há atuação de ventos de E-NE é possível encontrar Água Central do Atlântico Sul (ACAS) no interior da baía de Sepetiba, desde a sua entrada principal até as adjacências da ilha Guaíba. Além disso, foram identificadas diversas oscilações de baixa frequência que puderam ser associadas à variação da pressão atmosférica. Oscilações de alta frequência foram associadas à dinâmica da maré, a co-oscilações da maré e ao vento. Em relação à concentração de Material Particulado em Suspensão (MPS), durante os períodos de sizígia foram registradas as maiores concentrações material particulado na coluna dágua. Durante os períodos de sizígia, o fluxo de MPS é mais pronunciado do que durante as quadraturas, sendo que, independente do período da maré, o fluxo cumulativo de material particulado em suspensão é dirigido para o interior da baía de Sepetiba. Considerando o alinhamento dos vetores de velocidade em conformidade a direção preferencial do canal de navegação, tem-se que o fluxo cumulativo de MPS varia entre dirigido para SE na região próxima ao fundo, a dirigido para NE próximo ao topo da coluna dágua, o que sugere a deflexão do movimento das correntes em consequência do atrito. Ao longo de um dia, o fluxo do material particulado é mais pronunciado durante as enchentes, quando há aumento das tensões cisalhantes que atuam sobre o leito da baía redisponibilizando para a coluna dágua o material que estava depositado no fundo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Juvenile (mean +/- SE, 8.6 +/- 0.1 g) white sturgeon Acipenser transmontanus were fed for 8 weeks under one of six feeding regimens: continuously 24 h/d (C24); continuously 12.8 h/d during the day (C12/D), continuously 12.8 h/d at night (C12/N), 6 meals/d (M6), 4 meals/d (M4), and 2 meals/d (M2). Specific growth rate, feed efficiency, and body lipid content were significantly (P < 0.05) affected by the feeding regimen. These variables were highest in the C24 group and lowest in the M2 group; fish in the M6 group showed the second best performance. Specific growth rate and feed efficiency in terms of wet weight in the M6 groups were not significantly different from those in the C24 groups, but specific growth rate in terms of energy and energy retention efficiency were significantly lower. Feeding regimen had no effect on condition factor, hepatosomatic index, coefficient of variation in final body weight, and protein and ash contents. There was no significant difference in these indexes between 12.8-h/d continuous feeding by day or by night. It was concluded that continuous feeding for 24 h/d was the optimum feeding regimen for juvenile white sturgeon.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

人类线粒体DNA(mtDNA)是一个长度16,569bp 的环状分子,编码13 种蛋白 质、22 种tRNA 和2 种rRNA。由于mtDNA 全基因组信息具有缺乏重组、母系 遗传、高突变速率和相对较高的分辨率等特点,近年来已经成为重建人类历史的 重要工具。这些研究已经证实,mtDNA 最古老的六个单倍型类群,L0-L5,在非 洲特异的出现;而6-7 万年前从L3 衍生出的M 和N 两个超类群最终占领了世界 其他地区。然而,mtDNA 全序列研究在世界上某些特定地区尚是一片空白,其 中之一便是作为人类“走出非洲”的关键区域——印度。 为弥补这一空白,我们从 1200 个印度样品中选择了131 个可以代表所有主 要单倍型类群的个体,进行了全基因组扩增和测序,手工重建并软件验证了系统 发育关系树。我们的结果发现了12 个新的印度特有单倍型类群(N5, R7, R8, R30, R31, M34-M40),修订了11 个已知特有单倍型类群(N1d, R5, R6, U2a, U2b, U2c, M2, M4, M5, M6, M30)的定义,详细描述了存在于印度的欧洲特有类群(HV, JT, U, N1, W)。 这一工作产生了多个推论。第一个是关于人类“走出非洲”假说长期以来 存在的争论。欧亚大陆和大洋洲mtDNA 在M 和N(包括R)超类群系统发育关系 上星状和不重叠的分布,表明了人类走出非洲是沿着亚洲海岸线(即所谓的“南 方路线”)的一个快速扩散的过程。第二个推论是关于存在于印度的欧洲特有世 系。与典型的欧洲世系相比,这些世系仅仅存在一到两个突变,从而证实了新石 器时代以来来自于近东新月地带或中亚高原的基因流。第三个推论涉及一个早期 的印度全序列研究。仔细分析其数据表明,他们的数据丢失了很多基部的特有突 变并产生了多个幻影突变,从而证实了系统发育思想对检测数据质量的作用。 随着印度人群 mtDNA 全序列研究的完成,人类mtDNA 系统发育的基本框 架得以建立。人类mtDNA 明显地呈现出大洲特异性分布。目前已经有两种假说用来解释这一现象。传统的观点把这一现象归于遗传漂变;而近期的选择假说认 为选择在人类mtDNA 的分化中扮演了极其重要的角色,而气候是主要的选择压 力。为解决这一争论,我们收集了来自南亚、大洋洲和东亚三个具有不同气候的 地区的mtDNA,使用直接计数的办法比较了各个大洲之间同义突变和异义突变 的差异。结果表明,几乎在所有的基因中,异义突变的数量低于同义突变的数量, 从而表明纯净化选择是人类mtDNA 进化中的主要力量。然而,在这三个大洲之 间没有发现显著的差异,表明mtDNA 在这三个区域上所承受的选择压力基本相 同。这一结果表明,气候不大可能是造成人类mtDNA 分化的主要原因。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

根据优化输入端多模干涉器(MMI)结构设计,研制出32通道50GHz通道间隔、顶部平坦化的阵列波导光栅(AWG)器件。该器件的采用6μm×6μm折射率差为0.75%的Si基SiO2埋型波导结构,阵列波导数为130,罗兰圆半径为9419.72μm,相邻阵列波导长度差为128.42μm。测试结果表明

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文以苯并(a)芘为目标污染物,探讨了母体化合物BaP及其次生代谢产物的连续降解的方法、降解过程和微生物的酶蛋白应答,并运用种子(小麦、白菜和萝卜)根伸长生长实验,考查了BaP的不同降解时期次生代谢产物造成的复合污染整体效应,旨在探讨BaP及其次生代谢产物的降解影响因素,减少其环境累积,为BaP污染环境的全面修复提供实验依据和理论基础。 在实验条件下,运用HPLC鉴定出真菌FZSY-1降解BaP的同时生成了三个次生代谢产物BP1,6-quinone, BP7,8-diol 和 3-OHBP;同时鉴定出真菌FZSY-2降解BaP的同时生成了两个代谢产物BP1,6-quinone 和 3-OHBP。 驯化微生物与氧化剂(KMnO4)的耦合降解系统对BaP及其代谢产物的连续降解效果好于单纯微生物降解。三个次生代谢产物中,BP1,6-quinone在环境中最易累积。同时提出了微生物与氧化剂协同的作用可以有效促进环境中持久有机污染物(尤其是高浓度,小面积污染)的连续降解。对于FZSY-1与氧化剂(KMnO4)耦合降解BaP,在TW80存在下,与对照(未加TW80)相比,在降解的前期(3天取样),BaP及其代谢产物的降解相对滞后;而在降解的后期(12天取样),BaP及其代谢产物的降解高于对照。 在不同BaP浓度下,检测了四种酶,C120、C230、CAT和PPO。三株细菌的CAT酶活与BaP的浓度无关;三株细菌的C230酶活都比较高;三株细菌的PPO酶活均较低。加入共代谢底物(琥珀酸钠)后,与对照(未加入共代谢底物)相比,C120、C230酶活明显提高。 以BaP以及FZSY-1(BZSY-2)降解BaP不同时期的复合降解产物(BaP,M6,M12,CK)为目标污染物,它们对小麦种子根伸长的抑制作用顺序为:M6﹥BaP﹥M12﹥CK。BaP,M6,M12,CK对白菜和萝卜种子根伸长的抑制作用顺序和小麦相同;同一目标污染物(M6)对这几种供试种子(小麦、白菜和萝卜)根伸长的抑制作用顺序为小麦﹥白菜﹥萝卜;三种植物种子根伸长抑制作用均表现为:真菌的M6﹥细菌的M6,真菌的M12﹥细菌的M12。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

<正>通过MicroPIV/PTV系统测量带有微结构的PDMS微流道(22μm×6μm,长8mm)内的速度分布。流道侧壁的PDMS微结构是通过软光刻微加工工艺制成,其特征宽度在1~10μm范围。为了研究微结构尺寸的影响,我们测量了3种不同尺度微结构对速度分布的影响。示踪粒子为200nm聚苯乙烯荧光粒子。实验管道Re约0.01。