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Posterior decompression with instrumented fusion for thoracic myelopathy caused by ossification of the posterior longitudinal ligament

Yamazaki, Masashi; Okawa, Akihiko; Fujiyoshi, Takayuki; Furuya, Takeo; Koda, Masao
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
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We evaluated the clinical results of posterior decompression with instrumented fusion (PDF) for thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). A total of 24 patients underwent PDF, and their surgical outcomes were evaluated by the Japanese Orthopaedic Association (JOA) scores (0–11 points) and by recovery rates calculated at 3, 6, 9 and 12 months after surgery and at a mean final follow-up of 4 years and 5 months. The mean JOA score before surgery was 3.7 points. Although transient paralysis occurred immediately after surgery in one patient (3.8%), all patients showed neurological recovery at the final follow-up with a mean JOA score of 8.0 points and a mean recovery rate of 58.1%. The mean recovery rate at 3, 6, 9 and 12 months after surgery was 36.7, 48.8, 54.0 and 56.8%, respectively. The median time point that the JOA score reached its peak value was 9 months after surgery. No patient chose additional anterior decompression surgery via thoracotomy. The present findings demonstrate that despite persistent anterior impingement of the spinal cord by residual OPLL, PDF can result in considerable neurological recovery with a low risk of postoperative paralysis. Since neurological recovery progresses slowly after PDF...

A Nonparametric Riemannian Framework for Processing High Angular Resolution Diffusion Images and its Applications to ODF-based Morphometry

Goh, Alvina; Lenglet, Christophe; Thompson, Paul M.; Vidal, René
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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High angular resolution diffusion imaging (HARDI) has become an important technique for imaging complex oriented structures in the brain and other anatomical tissues. This has motivated the recent development of several methods for computing the orientation probability density function (PDF) at each voxel. However, much less work has been done on developing techniques for filtering, interpolation, averaging and principal geodesic analysis of orientation PDF fields. In this paper, we present a Riemannian framework for performing such operations. The proposed framework does not require that the orientation PDFs be represented by any fixed parameterization, such as a mixture of von Mises-Fisher distributions or a spherical harmonic expansion. Instead, we use a nonparametric representation of the orientation PDF. We exploit the fact that under the square-root re-parameterization, the space of orientation PDFs forms a Riemannian manifold: the positive orthant of the unit Hilbert sphere. We show that various orientation PDF processing operations, such as filtering, interpolation, averaging and principal geodesic analysis, may be posed as optimization problems on the Hilbert sphere, and can be solved using Riemannian gradient descent. We illustrate these concepts with numerous experiments on synthetic...

Asymmetric Lévy flight in financial ratios

Podobnik, Boris; Valentinčič, Aljoša; Horvatić, Davor; Stanley, H. Eugene
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Because financial crises are characterized by dangerous rare events that occur more frequently than those predicted by models with finite variances, we investigate the underlying stochastic process generating these events. In the 1960s Mandelbrot [Mandelbrot B (1963) J Bus 36:394–419] and Fama [Fama EF (1965) J Bus 38:34–105] proposed a symmetric Lévy probability distribution function (PDF) to describe the stochastic properties of commodity changes and price changes. We find that an asymmetric Lévy PDF, , characterized by infinite variance, models several multiple credit ratios used in financial accounting to quantify a firm’s financial health, such as the Altman [Altman EI (1968) J Financ 23:589–609] Z score and the Zmijewski [Zmijewski ME (1984) J Accounting Res 22:59–82] score, and models changes of individual financial ratios, ΔXi. We thus find that Lévy PDFs describe both the static and dynamics of credit ratings. We find that for the majority of ratios, ΔXi scales with the Lévy parameter α ≈ 1, even though only a few of the individual ratios are characterized by a PDF with power-law tails with infinite variance. We also find that α exhibits a striking stability over time. A key element in estimating credit losses is the distribution of credit rating changes...

Genome-Wide Identification and in Silico Analysis of Poplar Peptide Deformylases

Liu, Chang-Cai; Liu, Bao-Guang; Yang, Zhi-Wei; Li, Chun-Ming; Wang, Bai-Chen; Yang, Chuan-Ping
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 23/04/2012 Português
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Peptide deformylases (PDF) behave as monomeric metal cation hydrolases for the removal of the N-formyl group (Fo). This is an essential step in the N-terminal Met excision (NME) that occurs in these proteins from eukaryotic mitochondria or chloroplasts. Although PDFs have been identified and their structure and function have been characterized in several herbaceous species, it remains as yet unexplored in poplar. Here, we report on the first identification of two genes (PtrPDF1A and PtrPDF1B) respectively encoding two putative PDF polypeptides in Populus trichocarpa by genome-wide investigation. One of them (XP_002300047.1) encoded by PtrPDF1B (XM_002300011.1) was truncated, and then revised into a complete sequence based on its ESTs support with high confidence. We document that the two PDF1s of Populus are evolutionarily divergent, likely as a result of independent duplicated events. Furthermore, in silico simulations demonstrated that PtrPDF1A and PtrPDF1B should act as similar PDF catalytic activities to their corresponding PDF orthologs in Arabidopsis. This result would be value of for further assessment of their biological activities in poplar, and further experiments are now required to confirm them.

Risk assessment of nanomaterials in cosmetics: a European union perspective

Henkler, Frank; Tralau, Tewes; Tentschert, Jutta; Kneuer, Carsten; Haase, Andrea; Platzek, Thomas; Luch, Andreas; Götz, Mario E.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
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In Europe, the data requirements for the hazard and exposure characterisation of chemicals are defined according to the REACH regulation and its guidance on information requirements and chemical safety assessment (Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), and its guidance documents; available at: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:396:0001:0849:EN:PDF; and at: http://guidance.echa.europa.eu/docs/guidance_document/information_requirements_en.htm). This is the basis for any related risk assessment. The standard reference for the testing of cosmetic ingredients is the SCCP’s ‘Notes of Guidance for the Testing of Cosmetic Ingredients and their Safety Evaluation’ (The SCCP’s Notes of Guidance for the testing of cosmetic ingredients and their safety evaluation (2006); available at: http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_03j.pdf), which refers to the OECD guidelines for the testing of chemicals (The OECD Guidelines for the Testing of Chemicals as a collection of the most relevant internationally agreed testing methods used by government...

Retrograde Bone Morphogenetic Protein Signaling Shapes a Key Circadian Pacemaker Circuit

Gorostiza, E. Axel; Ceriani, M. Fernanda
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 09/01/2013 Português
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The neuropeptide pigment-dispersing factor (PDF) synchronizes molecular oscillations within circadian pacemakers in the Drosophila brain. It is expressed in the small ventral lateral neurons (sLNvs) and large ventral lateral neurons, the former being indispensable for maintaining behavioral rhythmicity under free-running conditions. How PDF circuits develop the specific connectivity traits that endow such global behavioral control remains unknown. Here, we show that mature sLNv circuits require PDF signaling during early development, acting through its cognate receptor PDFR at postsynaptic targets. Yet, axonal defects by PDF knockdown are presynaptic and become apparent only after metamorphosis, highlighting a delayed response to a signal released early on. Presynaptic expression of constitutively active bone morphogenetic protein (BMP) receptors prevents pdfr mutants misrouting phenotype, while sLNv-restricted downregulation of BMP signaling components phenocopied pdf01. Thus, we have uncovered a novel mechanism that provides an early “tagging” of synaptic targets that will guide circuit refinement later in development.

A HAT for sleep?: Epigenetic regulation of sleep by Tip60 in Drosophila

Pirooznia, Sheila K.; Elefant, Felice
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
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Sleep disturbances are common in neurodegenerative diseases such as Alzheimer disease (AD). Unfortunately, how AD is mechanistically linked with interference of the body’s natural sleep rhythms remains unclear. Our recent findings provide insight into this question by demonstrating that sleep disruption associated with AD is driven by epigenetic changes mediated by the histone acetyltransferase (HAT) Tip60. In this study, we show that Tip60 functionally interacts with the AD associated amyloid precursor protein (APP) to regulate axonal growth of Drosophila small ventrolateral neuronal (sLNv) pacemaker cells, and their production of neuropeptide pigment dispersing factor (PDF) that stabilizes appropriate sleep-wake patterns in the fly. Loss of Tip60 HAT activity under APP neurodegenerative conditions causes decreased PDF production, retraction of the sLNv synaptic arbor required for PDF release and disruption of sleep-wake cycles in these flies. Remarkably, excess Tip60 in conjunction with APP fully rescues these sleep-wake disturbances by inducing overelaboration of the sLNv synaptic terminals and increasing PDF levels, supporting a neuroprotective role for Tip60 in these processes. Our studies highlight the importance of epigenetic based mechanisms underlying sleep disturbances in neurodegenerative diseases like AD.

Pigment-Dispersing Factor Modulates Pheromone Production in Clock Cells that Influence Mating in Drosophila

Krupp, Joshua J.; Billeter, Jean-Christophe; Wong, Amy; Choi, Charles; Nitabach, Michael N.; Levine, Joel D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 10/07/2013 Português
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Social cues contribute to the circadian entrainment of physiological and behavioral rhythms. These cues supplement the influence of daily and seasonal cycles in light and temperature. In Drosophila, the social environment modulates circadian mechanisms that regulate sex pheromone production and mating behavior. Here we demonstrate that a neuroendocrine pathway, defined by the neuropeptide Pigment-Dispersing Factor (PDF), couples the central nervous system (CNS) to the physiological output of peripheral clock cells that produce pheromones, the oenocytes. PDF signaling from the CNS modulates the phase of the oenocyte clock. Despite its requirement for sustaining free-running locomoter activity rhythms, PDF is not necessary to sustain molecular rhythms in the oenocytes. Interestingly, disruption of the PDF signaling pathway reduces male sex pheromones and results in sex-specific differences in mating behavior. Our findings highlight the role of neuropeptide signaling and the circadian system in synchronizing the physiological and behavioral processes which govern social interactions.

Nematode and Arthropod Genomes Provide New Insights into the Evolution of Class 2 B1 GPCRs

Cardoso, João C. R.; Félix, Rute C.; Power, Deborah M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 20/03/2014 Português
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Nematodes and arthropods are the most speciose animal groups and possess Class 2 B1 G-protein coupled receptors (GPCRs). Existing models of invertebrate Class 2 B1 GPCR evolution are mainly centered on Caenorhabditis elegans and Drosophila melanogaster and a few other nematode and arthropod representatives. The present study reevaluates the evolution of metazoan Class 2 B1 GPCRs and orthologues by exploring the receptors in several nematode and arthropod genomes and comparing them to the human receptors. Three novel receptor phylogenetic clusters were identified and designated cluster A, cluster B and PDF-R-related cluster. Clusters A and B were identified in several nematode and arthropod genomes but were absent from D. melanogaster and Culicidae genomes, whereas the majority of the members of the PDF-R-related cluster were from nematodes. Cluster A receptors were nematode and arthropod-specific but shared a conserved gene environment with human receptor loci. Cluster B members were orthologous to human GCGR, PTHR and Secretin members with which they probably shared a common origin. PDF-R and PDF-R related clusters were present in representatives of both nematodes and arthropods. The results of comparative analysis of GPCR evolution and diversity in protostomes confirm previous notions that C. elegans and D. melanogaster genomes are not good representatives of nematode and arthropod phyla. We hypothesize that at least four ancestral Class 2 B1 genes emerged early in the metazoan radiation...

Estudo da freqüência haplotípica dos marcadores microssatélites ligados ao cromossomo X, DXS7424, DXS101, DXS10079, DXS10075 e DXS10074 na população de Alagoas; Study of the haplotype frequency of microsatellite markers linked to the X chromosome , DXS7424, DXS101, DXS10079, DXS10075, DXS10074 and the population of Alagoas

Silva, Iede Hercília Emerenciano Ferreira da
Fonte: Universidade Federal de Alagoas; BR; Biologia; Programa de Pós-Graduação em Ciências da Saúde; UFAL Publicador: Universidade Federal de Alagoas; BR; Biologia; Programa de Pós-Graduação em Ciências da Saúde; UFAL
Tipo: Dissertação Formato: application/pdf
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The STR markers linked to the X chromosome can be used for complement the analysis of autosomal markers, especially in complex cases of kinship testing, in cases of post-morten identification and in paternity testing, when the disputed child is a girl. The aim of this work was investigate five STR X-chromosome markers (DXS10079, DXS10074, DXS10075, DXS7424 and DXS101) in the population of Alagoas, Brazil and analyze their frequencies for forensic purposes. The sample was composed of 404 unrelated individuals, 203 males and 201 females. The DNA was extracted using Chelex procedure and amplification was performed by PCR in a pentaplex system and the fragments were separated by capillary electrophoresis. For the studied STR markers, it was calculated the allele and haplotype frequencies, the observed and expected Heterozygosity values, the Hardy Weinberg equilibrium (HWE), the genetic diversity, the Mean Exclusion Chance of trios involving daughters (MECT) as well as in father/daughter duos (MECD). Also, it was calculated Power of Discrimination in males (PDM) and in females (PDF) and the Polymorphism Information Content (PIC). The forensic efficiency values demonstrate that DXS101 is a highly informative marker, followed by DXS10074...

Normality tests for spatialy correlated data

Pardo-Iguzquiza, E.; Dowd, P.
Fonte: Kluwer Academic/Plenum Publ Publicador: Kluwer Academic/Plenum Publ
Tipo: Artigo de Revista Científica
Publicado em //2004 Português
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In studies that involve a finite sample size of spatial data it is often of interest to test (statistically) the assumption that the marginal (or univariate) distribution of the data is Gaussian (normal). This may be important per se because, for example, a data transformation may be desired if the normality hypothesis is rejected, or it may provide a way of testing other hypotheses, such as lognormality, by testing the normality of the logarithms of the observations. The most commonly used tests, such as the Kolmogorov–Smirnov (K–S), chi-square (χ2), and Shapiro–Wilks (S–W) tests, are designed on the assumption that the observations are independent and identically distributed (iid). In geostatistical applications, however, this is not usually the case unless the spatial covariance (semivariogram) function is a pure nugget variance. If the covariance structure has a (practical) range greater than the minimum distance between observations, the data are correlated and the standard tests cannot be applied to the probability density function (pdf) or cumulative probability function (cdf) estimated directly from the data. The problem with correlated data arises not from the correlation per se but from cases in which correlated data are clustered rather than being located on a regular grid. In these cases inferences requiring iid assumptions may be seriously biased because of the spatial correlation among the observations. If unbiased (i.e....

"Untersuchungen zum Wandel hallstattzeitlicher Bestattungssitten in Süd- und Südwestdeutschland" (Datenbank); "Studies on the transformation of Hallstatt burial customs in south and southwest Germany" (Database)

Müller-Scheeßel, Nils
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Sonstiges
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Die hier veröffentlichte Datei stellt die gezippte Datenbank der Arbeit "Untersuchungen zum Wandel hallstattzeitlicher Bestattungssitten in Süd- und Südwestdeutschland" dar, veröffentlicht 2013 als Band 138 der Reihe "Universitätsforschungen zur Prähistorischen Archäologie" bei R. Habelt, Bonn. Besagte Arbeit hat sich der Aufgabe gewidmet, die Veränderungen der hallstattzeitlichen Bestattungssitten in Baden-Württemberg und Bayern unter Einbeziehung kulturvergleichender Überlegungen zu untersuchen. Das Zip-Archiv enthielt die Tabellen der Datenbank im ASCII-Format, ein ER-Diagramm im pdf-Format, das die Beziehungen der Tabellen zueinander darstellt sowie eine weitere pdf-Datei mit der Aufschlüsselung der Spalten der Einzeltabellen und ihres Formats.; The file published here is the zipped database of the work "Studies on the transformation of Hallstatt burial customs in south and southwest Germany" which was published in 2013 as volume 138 of the series "Universitätsforschungen zur Prähistorischen Archäologie" by R. Habelt, Bonn. The said work set out to investigate the changes in Hallstatt burial customs in Baden-Württemberg and Bavaria, taking into account cross-cultural considerations. The zip archive contains the database tables in ASCII format...

STUDENT ALCOHOL QUESTIONNAIRE AND THE CODE (1987); THE 1987-88 STUDENT ALCOHOL QUESTIONNAIRE, AND CODEPENDENCY QUESTIONNAIRE

Engs, Ruth C
Fonte: Universidade de Indiana Publicador: Universidade de Indiana
Tipo: Questionnaire
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The first questionnaire, SAQ_ CODE87.pdf, was used for comparison of a sample of Ontario, Canada and American Midwestern students from states around the great Lakes. The Ontario questionnaire is found at the IUScholarWorks repository: http://hdl.handle.net/2022/17184. It was used to examine drinking patterns and problems of university students during 1987-8 and over three time periods. The classic SAQ is found at : http://hdl.handle.net/2022/17153; 3) It was was used to determine the codependency status of students in relationship to drinking patterns. The second questionnaire, SAQ_ HCQ_CODE87Quest Dev.pdf, was used for reliability and internal consistency of the CODE and also the Health Concern Questionnaire. The CODE questionnaire was used to determine alcoholism in a family. The experimental and final versions of the CODE are found at are found at: http://hdl.handle.net/2022/17248. Both versions of the HCQ are found at: http://hdl.handle.net/2022/17250 Data Base and CALCULATIONS for all questionnaires are found at: https://scholarworks.iu.edu/dspace/handle/2022/17140/browse?type=dateissued. Research papers using this questionnaire can be found at: https://scholarworks.iu.edu/dspace/handle/2022/17130/browse?type=dateissued; https://scholarworks.iu.edu/dspace/handle/2022/17127/browse?type=dateissued and https://scholarworks.iu.edu/dspace/handle/2022/17124/browse?type=dateissued. ALL QUESTIONNAIRES developed by Engs are found on the repository at: https://scholarworks.iu.edu/dspace/handle/2022/17141/browse?type=dateissued; This 1987 questionnaire (SAQ_ CODE87.pdf) contains scales for several studies.It contains drinking behaviors...

Analysis and downscaling multi-model seasonal forecasts in Peru using self-organizing maps

Gutiérrez Llorente, José Manuel; Cano Trueba, Rafael; Cofiño González, Antonio Santiago; Sordo García, Carmen María
Fonte: International Meteorological Institute in Stockholm Publicador: International Meteorological Institute in Stockholm
Tipo: info:eu-repo/semantics/article; publishedVersion
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We present an application of self-organizing maps (SOMs) for analysing multi-model ensemble seasonal forecasts from the DEMETER project in the tropical area of Northern Peru. The SOM is an automatic data-mining clustering technique, which allows us to summarize a high-dimensional data space in terms of a set of reference vectors (cluster centroids). Moreover, it has outstanding analysis and visualization properties, because the reference vectors can be projected into a two-dimensional lattice, preserving their high-dimensional topology. In the first part of the paper, the SOM is applied to analyse both atmospheric patterns over Peru and local precipitation observations at two nearby stations. First, the method is applied to cluster the ERA40 reanalysis patterns on the area of study (Northern Peru), obtaining a two-dimensional lattice which represents the climatology. Then, each particular phenomenon or event (e.g. El Niño or La Niña) is shown to define a probability density function (PDF) on the lattice, which represents its characteristic ‘location’ within the climatology. On the other hand, the climatological lattice is also used to represent the local precipitation regime associated with a given station. For instance, we show that the precipitation regime is strongly associated with El Niño events for one station...

Caminhadas com memória em meios regulares e desordenados: aspectos estáticos e dinâmicos; Memory Walks in Regular and Disordered Media: Static and Dynamic Features

Granzotti, Cristiano Roberto Fabri
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/03/2015 Português
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Propomos o estudo do meio desordenado onde a caminhada determinista parcialmente autorrepulsiva (CDPA) é desenvolvida e o estudo da caminhada aleatória autorrepulsiva (SAW) em rede regular. O meio desordenado na CDPA, gerado por um processo Poissônico espacial, é caracterizado pela estatística de vizinhança e de distâncias. A estatística de vizinhança mede a probabilidade de um ponto ser $m$-ésimo vizinho mais próximo de seu $n$-ésimo vizinho mais próximo. A estatística de distâncias mede a distribuição de distância de um ponto ao seu $k$-ésimo vizinho mais próximo. No problema da estatística de distâncias, calculamos a função densidade de probabilidade (pdf) e estudamos os casos limites de alta ordem de vizinhança e alta dimensionalidade. Um caso particular dessa pdf pode verificar se um conjunto de pontos foi gerado por um processo Poissônico. Na SAW em rede regular, um caminhante escolhe aleatoriamente um sítio adjacente para ser visitado no próximo passo, mas é proibido visitar um sítio duas ou mais vezes. Desenvolvemos uma nova abordagem para estudar grandezas conformacionais por meio do produto escalar entre o vetor posição e vetor deslocamento no $j$-ésimo passo: $\langle\vec{R}_{j}\cdot\vec{u}_{j}angle_{N}$. Mostramos que para $j=N$ o produto escalar é igual ao comprimento de persistência (projeção do vetor posição na direção do primeiro passo) e que converge para uma constante. Calculamos a distância quadrática média ponta-a-ponta...

Pion valence-quark parton distribution function

Chang, L.; Thomas, A.W.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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Within the Dyson–Schwinger equation formulation of QCD, a rainbow ladder truncation is used to calculate the pion valence-quark distribution function (PDF). The gap equation is renormalized at a typical hadronic scale, of order 0.5 GeV, which is also set as the default initial scale for the pion PDF. We implement a corrected leading-order expression for the PDF which ensures that the valence-quarks carry all of the pion's light-front momentum at the initial scale. The scaling behavior of the pion PDF at a typical partonic scale of order 5.2 GeV is found to be (1−x)ν, with ν≃1.6, as x approaches one.; Lei Chang, Anthony W. Thomas

Repositórios institucionais brasileiros: entre o sonho e a realidade

Maria das Graças Targino; Universidade Federal da Paraíba
; Joana Coeli Ribeiro Garcia; Universidade Federal da Paraíba; Maria José Rodrigues Paiva; Universidade Federal da Paraíba
Fonte: BIREDIAL Publicador: BIREDIAL
Tipo: Trabajo revisado (Peer-reviewed) Formato: application/pdf; application/vnd.ms-powerpoint
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Percebido como locus online para coleta, preservação e disseminação da produção intelectual e científica de uma instituição (ênfase para universidades e institutos de pesquisa), o repositório institucional (RI) representa proposta alternativa para a comunicação científica. Isto porque, altera substancialmente a cadeia de produção, disseminação e uso do conhecimento registrado no âmbito das organizações, antes universo exclusivo dos editores comerciais. Consequentemente, o RI atua como instrumento de ação política e ocupa papel relevante na discussão sobre direitos autorais e impactos da ciência e tecnologia em diferentes esferas científicas, tecnológicas e sociais. Alinha-se, portanto, com dois movimentos internacionais – a Open Archives Initiative (OAI, http://www.openarchives.org) e o movimento do Acesso Aberto (Open Access, http://www.ibict.br/openaccess). Estes, em trabalho conjunto, asseguram o acesso gratuito, livre, irrestrito e, portanto, público à informação disponibilizada no meio eletrônico, em especial, àquela produzida mediante financiamento público, configurando-se como estrutura de sustentação para a quebra da hegemonia das editoras científicas comerciais. Ademais, o RI, em termos genéricos...

ELECTROKINETIC PHENOMENA. II : THE FACTOR OF PROPORTIONALITY FOR CATAPHORETIC AND ELECTROENDOSMOTIC MOBILITIES

Abramson, Harold A.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/07/1930 Português
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Two theories which predict different values for the ratio of VE, the electroendosmotic velocity of a liquid past a surface, to Vp, the electric mobility of a particle of the same surface through the same liquid are discussed. The theory demanding that See PDF for Equation was supported by certain data of van der Grinten for a glass surface. Re-calculation of van der Grinten's data reveals that the ratio varies between 2.1 and 2.8. These results are in accord with previous data of Abramson. It is pointed out that glass is unsuitable for the investigation. The ratio See PDF for Equation is here determined for a flat surface and particles when both are covered by the same proteins. Under these conditions See PDF for Equation The theory is similarly tested for a round surface using a micro-cataphoresis cell. It is shown that See PDF for Equation for a round surface is approximately 1.00. These findings are confirmatory of previous data supporting the view that cataphoretic mobility is independent of the size and shape of the particles when all particles compared have similar surface constitutions.

Peritoneal Dialysis as a First versus Second Option after Previous Haemodialysis: A Very Long-Term Assessment

Barone, Roberto José; Cámpora, María Inés; Gimenez, Nélida Susana; Ramirez, Liliana; Panese, Sergio Alberto; Santopietro, Mónica
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
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For renal replacement therapy, overall survival is more important than the choice of currently available individual therapy. Objectives. To compare patients and technique survival on peritoneal dialysis as first treatment (PDF) versus after previous haemodialysis (HDPD) and other indicators of follow-up. Methods. We prospectively studied 110 incident patients, during the period from August 4, 1993, to June 30, 2012, for patients and technique survival (Kaplan-Meier) (log rank P < 0.05). Results. Groups: (A) PDF: 37 patients, 24 females, age: 52.2 ± 14.9 years old, time at risk: 2123 patient-months (p/m), mean: 57 ± 42 months; (B) HDPD: 73 patients, 42 females, age: 52.45 ± 14.7 years old, time in haemodialysis: 3569.2 (p/m), range: 3–216 months, mean: 49 ± 45 months, time at risk in PD: 3700 (p/m), mean: 51 ± 49 months. Patients' survival: (A) PDF: 100%, 76.6%, 65.6%, and 19.7%; (B) HDPD: 95.4%, 65.6%, 43%, and 43% at 12, 60, 120, and 144 months, respectively, P = 0.34. Technique: (A) PDF: 100%, 90%, 59.8%, and 24%; (B) HDPD: 94%, 75%, 32%, and 32% at 12, 60, 120, and 144 months, respectively, P = 0.40. Conclusions. Comparable patient and technique survival were observed. Peritoneal dialysis enables a greater extension of renal replacement therapy for patients with serious difficulties continuing with haemodialysis.

Characterization of a Novel Fucose-Regulated Promoter (PfcsK) Suitable for Gene Essentiality and Antibacterial Mode-of-Action Studies in Streptococcus pneumoniae

Chan, Pan F.; O'Dwyer, Karen M.; Palmer, Leslie M.; Ambrad, Jennifer D.; Ingraham, Karen A.; So, Chi; Lonetto, Michael A.; Biswas, Sanjoy; Rosenberg, Martin; Holmes, David J.; Zalacain, Magdalena
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2003 Português
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The promoter of the Streptococcus pneumoniae putative fuculose kinase gene (fcsK), the first gene of a novel fucose utilization operon, is induced by fucose and repressed by glucose or sucrose. When the streptococcal polypeptide deformylase (PDF) gene (def1, encoding PDF) was placed under the control of PfcsK, fucose-dependent growth of the S. pneumoniae (PfcsK::def1) strain was observed, confirming the essential nature of PDF in this organism. The mode of antibacterial action of actinonin, a known PDF inhibitor, was also confirmed with this strain. The endogenous fuculose kinase promoter is a tightly regulated, titratable promoter which will be useful for target validation and for confirmation of the mode of action of novel antibacterial drugs in S. pneumoniae.