907 resultados para P-scale
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Species?habitat associations may contribute to the maintenance of species richness in tropical forests, but previous research has been conducted almost exclusively in lowland forests and has emphasized the importance of topography and edaphic conditions. Is the distribution of woody plant species in a Peruvian cloud forest determined by microhabitat conditions? What is the role of environmental characteristics and forest structure in habitat partitioning in a tropical cloud forest? We examined species?habitat associations in three 1-ha plots using the torus-translation method. We used three different criteria to define habitats for habitat partitioning analyses, based on microtopography, forest structure and both sets of factors. The number of species associated either positively or negatively with each habitat was assessed. Habitats defined on the basis of environmental conditions and forest structure discriminated a greater number of positive and negative associations at the scale of our analyses in a tropical cloud forest. Both topographic conditions and forest structure contribute to small-scale microhabitat partitioning of woody plant species in a Peruvian tropical cloud forest. Nevertheless, canopy species were most correlated with the distribution of environmental variables, while understorey species displayed associations with forest structure.
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Con el auge del Cloud Computing, las aplicaciones de proceso de datos han sufrido un incremento de demanda, y por ello ha cobrado importancia lograr m�ás eficiencia en los Centros de Proceso de datos. El objetivo de este trabajo es la obtenci�ón de herramientas que permitan analizar la viabilidad y rentabilidad de diseñar Centros de Datos especializados para procesamiento de datos, con una arquitectura, sistemas de refrigeraci�ón, etc. adaptados. Algunas aplicaciones de procesamiento de datos se benefician de las arquitecturas software, mientras que en otras puede ser m�ás eficiente un procesamiento con arquitectura hardware. Debido a que ya hay software con muy buenos resultados en el procesamiento de grafos, como el sistema XPregel, en este proyecto se realizará una arquitectura hardware en VHDL, implementando el algoritmo PageRank de Google de forma escalable. Se ha escogido este algoritmo ya que podr��á ser m�ás eficiente en arquitectura hardware, debido a sus características concretas que se indicaráan m�ás adelante. PageRank sirve para ordenar las p�áginas por su relevancia en la web, utilizando para ello la teorí��a de grafos, siendo cada página web un vértice de un grafo; y los enlaces entre páginas, las aristas del citado grafo. En este proyecto, primero se realizará un an�álisis del estado de la técnica. Se supone que la implementaci�ón en XPregel, un sistema de procesamiento de grafos, es una de las m�ás eficientes. Por ello se estudiará esta �ultima implementaci�ón. Sin embargo, debido a que Xpregel procesa, en general, algoritmos que trabajan con grafos; no tiene en cuenta ciertas caracterí��sticas del algoritmo PageRank, por lo que la implementaci�on no es �optima. Esto es debido a que en PageRank, almacenar todos los datos que manda un mismo v�értice es un gasto innecesario de memoria ya que todos los mensajes que manda un vértice son iguales entre sí e iguales a su PageRank. Se realizará el diseño en VHDL teniendo en cuenta esta caracter��ística del citado algoritmo,evitando almacenar varias veces los mensajes que son iguales. Se ha elegido implementar PageRank en VHDL porque actualmente las arquitecturas de los sistemas operativos no escalan adecuadamente. Se busca evaluar si con otra arquitectura se obtienen mejores resultados. Se realizará un diseño partiendo de cero, utilizando la memoria ROM de IPcore de Xillinx (Software de desarrollo en VHDL), generada autom�áticamente. Se considera hacer cuatro tipos de módulos para que as�� el procesamiento se pueda hacer en paralelo. Se simplificar�á la estructura de XPregel con el fin de intentar aprovechar la particularidad de PageRank mencionada, que hace que XPregel no le saque el m�aximo partido. Despu�és se escribirá el c�ódigo, realizando una estructura escalable, ya que en la computación intervienen millones de páginas web. A continuación, se sintetizar�á y se probará el código en una FPGA. El �ultimo paso será una evaluaci�ón de la implementaci�ón, y de posibles mejoras en cuanto al consumo.
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Acknowledgements James J. Waggitt was funded by a NERC Case studentship supported by OpenHydro Ltd and Marine Scotland Science (NE/J500148/1). Vessel-based transects were funded by a NERC (NE/J004340/1) and a Scottish National Heritage (SNH) grant. FVCOM modelling was funded by a NERC grant (NE/J004316/1). Marine Scotland Science provided time on the FRV Alba-na-Mara as part as the Marine Collaboration Research Forum (MarCRF). The bathymetry data used in hydrodynamic models (HI 1122 Sanday Sound to Westray Firth) was collected by the Maritime & Coastguard Agency (MCA) as part of the UK Civil Hydrography Programme. We wish to thank Christina Bristow, Matthew Finn and Jennifer Norris at the European Marine Energy Centre (EMEC); Marianna Chimienti, Ciaran Cronin, Tim Sykes and Stuart Thomas for performing vessel-based transects; Marine Scotland Science staff Eric Armstrong, Ian Davies, Mike Robertson, Robert Watret and Michael Stewart for their assistance; Shaun Fraser, Pauline Goulet, Alex Robbins, Helen Wade and Jared Wilson for invaluable discussions; Thomas Cornulier, Alex Douglas, James Grecian and Samantha Patrick for their help with statistical analysis; and Gavin Siriwardena, Leigh Torres, Mark Whittingham and Russell Wynn for their constructive comments on earlier versions of this manuscript.
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© 2015 American Heart Association, Inc.
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Pseudomonas aeruginosa, an opportunistic human pathogen, is a major causative agent of mortality and morbidity in immunocompromised patients and those with cystic fibrosis genetic disease. To identify new virulence genes of P. aeruginosa, a selection system was developed based on the in vivo expression technology (IVET) that was first reported in Salmonella system. An adenine-requiring auxotrophic mutant strain of P. aeruginosa was isolated and found avirulent on neutropenic mice. A DNA fragment that can complement the mutant strain, containing purEK operon that is required for de novo biosynthesis of purine, was sequenced and used in the IVET vector construction. By applying the IVET selection system to a neutropenic mouse infection model, genetic loci that are specifically induced in vivo were identified. Twenty-two such loci were partially sequenced and analyzed. One of them was a well-studied virulence factor, pyochelin receptor (FptA), that is involved in iron acquisition. Fifteen showed significant homology to reported sequences in GenBank, while the remaining six did not. One locus, designated np20, encodes an open reading frame that shares amino acid sequence homology to transcriptional regulators, especially to the ferric uptake regulator (Fur) proteins of other bacteria. An insertional np20 null mutant strain of P. aeruginosa did not show a growth defect on laboratory media; however, its virulence on neutropenic mice was significantly reduced compared with that of a wild-type parent strain, demonstrating the importance of the np20 locus in the bacterial virulence. The successful isolation of genetic loci that affect bacterial virulence demonstrates the utility of the IVET system in identification of new virulence genes of P. aeruginosa.
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We present a series of 8.4-GHz very-long-baseline radio interferometry images of the nucleus of Centaurus A (NGC5128) made with a Southern Hemisphere array, representing a 3.3-year monitoring effort. The nuclear radio jet is approximately 50 milliarcseconds in extent, or at the 3.5-megaparsec distance of NGC5128, approximately 1 parsec in length. Subluminal motion is seen and structural changes are observed on time scales shorter than 4 months. High-resolution observations at 4.8 and 8.4 GHz made in November 1992 reveal a complex morphology and allow us to unambiguously identify the self-absorbed core located at the southwestern end of the jet.
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Introdução: As precauções-padrão (PP) constituem um conjunto de medidas que têm como finalidade minimizar o risco de transmissão ocupacional de patógenos, sendo indispensável sua utilização por profissionais de saúde, sobretudo pelos enfermeiros. No entanto, a não adesão às PP constitui problemática amplamente discutida em todo o mundo. Embora haja diversos estudos brasileiros que visem avaliar a adesão às PP , ainda tem-se observado grande fragilidade no processo de construção e de validação dos instrumentos utilizados para avaliação deste construto. Objetivo: Realizar a adaptação cultural e validação da Compliance with Standard Precautions Scale (CSPS) para enfermeiros brasileiros. Metodologia: Trata-se de um estudo metodológico para a adaptação e validação da CSPS. Essa escala é composta por 20 itens com quatro opções de respostas, e destina-se a avaliar a adesão às PP. O processo de adaptação consistiu em Tradução, Consenso entre Juízes, Retrotradução e Validação Semântica. A primeira etapa foi a tradução do idioma original para o português do Brasil. Após foi realizado um comitê composto por sete juízes, a versão de consenso obtida na etapa anterior foi traduzida novamente para o idioma de origem. Foram avaliadas as propriedades psicométricas do instrumento, considerando-se as validades de face e de conteúdo, a validade de construto e a confiabilidade. A versão para o Português do Brasil da CSPS (CSPS-PB) foi aplicada em uma amostra de 300 enfermeiros que atuam na assistência a pacientes em um hospital localizado na cidade de São Paulo/SP. A confiabilidade foi avaliada por meio da consistência interna (alfa de Cronbach) e teste reteste (coeficiente de correlação intraclasse - ICC). Para a validação de construto, foi utilizada a comparação entre grupos diferentes, análise fatorial exploratória e análise fatorial confirmatória, segundo o Modelo de Equações Estruturais (SEM). Utilizou-se o software IBM® SPSS, 19.0. Para a análise fatorial confirmatória foi utilizado o módulo específico Analysis of Moment Structures (IBM® SPSS AMOS). Para a análise paralela utilizou-se o programa RanEigen Syntax. O nível de significância adotado foi ? = 0,05. Todos os aspectos éticos foram contemplados. Resultados: A tradução realizada por tradutores juramentados garantiu qualidade a esse processo. A validação de face e de conteúdo possibilitou a realização de modificações pertinentes e imperativas a fim de atender aos critérios de equivalências conceituais, idiomáticas, culturais e semânticas. Obteve-se ?=0,61 na avaliação da consistência interna, indicando confiabilidade satisfatória. O ICC indicou uma correlação de 0,87 quase perfeita para o teste reteste duas semanas após a primeira abordagem, conferindo estabilidade satisfatória. A validade de construto mostrou que a CSPS-PB foi capaz de discriminar as médias de adesão às PP entre grupos distintos referente à idade (F=5,15 p<=0,01), ao tempo de experiência clínica (F = 8,9 p<= 0,000) e a ter recebido treinamento (t = 2,48 p<=0,01). Na análise fatorial confirmatória, o modelo foi subidentificado. A análise fatorial exploratória indicou que todos os itens apresentaram cargas fatoriais adequadas (>=0,30), sendo identificados quatro fatores pela análise paralela. O total de variância explicada foi de 35,48%. Conclusão: A CSPS-PB, trata-se de um instrumento adequado, confiável e válido para medir a adesão às PP entre enfermeiros brasileiros
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We combine multi-wavelength data in the AEGIS-XD and C-COSMOS surveys to measure the typical dark matter halo mass of X-ray selected active galactic nuclei (AGN) [L_X(2–10 keV) > 10^42 erg s^− 1] in comparison with far-infrared selected star-forming galaxies detected in the Herschel/PEP survey (PACS Evolutionary Probe; L_IR > 10^11 L_⊙) and quiescent systems at z ≈ 1. We develop a novel method to measure the clustering of extragalactic populations that uses photometric redshift probability distribution functions in addition to any spectroscopy. This is advantageous in that all sources in the sample are used in the clustering analysis, not just the subset with secure spectroscopy. The method works best for large samples. The loss of accuracy because of the lack of spectroscopy is balanced by increasing the number of sources used to measure the clustering. We find that X-ray AGN, far-infrared selected star-forming galaxies and passive systems in the redshift interval 0.6 < z < 1.4 are found in haloes of similar mass, log M_DMH/(M_⊙ h^−1) ≈ 13.0. We argue that this is because the galaxies in all three samples (AGN, star-forming, passive) have similar stellar mass distributions, approximated by the J-band luminosity. Therefore, all galaxies that can potentially host X-ray AGN, because they have stellar masses in the appropriate range, live in dark matter haloes of log M_DMH/(M_⊙ h^−1) ≈ 13.0 independent of their star formation rates. This suggests that the stellar mass of X-ray AGN hosts is driving the observed clustering properties of this population. We also speculate that trends between AGN properties (e.g. luminosity, level of obscuration) and large-scale environment may be related to differences in the stellar mass of the host galaxies.
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The determination of the potentials of zero total and free charge, pztc and pzfc respectively, were made in a wide pH range by using the CO displacement method and the same calculation assumptions used previously for Pt(1 1 1) electrodes in contact with non-specifically adsorbing anions. Calculation of the pzfc involves, in occasions, long extrapolations that lead us to the introduction of the concept of potential of zero extrapolated charge (pzec). It was observed that the pztc changes with pH but the pzec is independent of this parameter. It was observed that the pztc > pzec at pH > 3.4 but the opposite is true for pH > 3.4. At the latter pH both pzec and pztc coincide. This defines two different pH regions and means that adsorbed hydrogen has to be corrected in the “acidic” solutions at the pztc while adsorbed OH is the species to be corrected in the “alkaline” range. The comparison of the overall picture suggests that neutral conditions at the interface are attained at significantly acidic solutions than those at the bulk.
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ex novissimis subsidiis ac relationibus ad normam legitimae proiectionis in usum belli praesentis delineata impensis homannianorum heredum.
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Modelling the susceptibility of permafrost slopes to disturbance can identify areas at risk to future disturbance and result in safer infrastructure and resource development in the Arctic. In this study, we use terrain attributes derived from a digital elevation model, an inventory of permafrost slope disturbances known as active-layer detachments (ALDs) and generalised additive modelling to produce a map of permafrost slope disturbance susceptibility for an area on northern Melville Island, in the Canadian High Arctic. By examining terrain variables and their relative importance, we identified factors important for initiating slope disturbance. The model was calibrated and validated using 70 and 30 per cent of a data-set of 760 mapped ALDs, including disturbed and randomised undisturbed samples. The generalised additive model calibrated and validated very well, with areas under the receiver operating characteristic curve of 0.89 and 0.81, respectively, demonstrating its effectiveness at predicting disturbed and undisturbed samples. ALDs were most likely to occur below the marine limit on slope angles between 3 and 10° and in areas with low values of potential incoming solar radiation (north-facing slopes).
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A classic T-cell phenotype in systemic lupus erythematosus (SLE) is the downregulation and replacement of the CD3ζ chain that alters T-cell receptor signaling. However, genetic associations with SLE in the human CD247 locus that encodes CD3ζ are not well established and require replication in independent cohorts. Our aim was therefore to examine, localize and validate CD247-SLE association in a large multiethnic population. We typed 44 contiguous CD247 single-nucleotide polymorphisms (SNPs) in 8922 SLE patients and 8077 controls from four ethnically distinct populations. The strongest associations were found in the Asian population (11 SNPs in intron 1, 4.99 × 10(-4) < P < 4.15 × 10(-2)), where we further identified a five-marker haplotype (rs12141731-rs2949655-rs16859085-rs12144621-rs858554; G-G-A-G-A; P(hap) = 2.12 × 10(-5)) that exceeded the most associated single SNP rs858554 (minor allele frequency in controls = 13%; P = 4.99 × 10(-4), odds ratio = 1.32) in significance. Imputation and subsequent association analysis showed evidence of association (P < 0.05) at 27 additional SNPs within intron 1. Cross-ethnic meta-analysis, assuming an additive genetic model adjusted for population proportions, showed five SNPs with significant P-values (1.40 × 10(-3) < P< 3.97 × 10(-2)), with one (rs704848) remaining significant after Bonferroni correction (P(meta) = 2.66 × 10(-2)). Our study independently confirms and extends the association of SLE with CD247, which is shared by various autoimmune disorders and supports a common T-cell-mediated mechanism.
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A perturbação do processamento auditivo pode afectar negativamente o comportamento auditivo da criança, levando, entre outros, a um baixo rendimento escolar e a alterações do comportamento. Por este motivo é importante a identificação precoce desta perturbação. No entanto em Portugal não se encontra nenhum instrumento de medida disponível para o efeito, o que motivou este estudo. Assim sendo, este estudo tem como objectivos a tradução, adaptação cultural e validação da escala Children's Auditory Processing Performance Scale (CHAPPS) (Smoski, Brunt, & Tannahill, 1992) para o Português Europeu. Depois de traduzida e adaptada culturalmente a escala foi validada. Esta foi administrada a 154 indivíduos, dos quais 125 eram pais/encarregados de educação e 29 eram professores de crianças em idade escolar, do 1º ciclo. A versão portuguesa da escala (P-CHAPPS) apresentou uma excelente consistência interna (=0,950), estabilidade temporal e uma correlação entre as subescalas e o total com valores entre 0,581 e 0,857. As características psicométricas da P-CHAPPS revelam que esta pode ser utilizada na população portuguesa, ficando assim disponível, em Portugal um instrumento de medida a ser utilizado na identificação precoce das perturbações do processamento auditivo.
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We present a study on the dependence of electric breakdown discharge properties on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).