703 research outputs found

    Orthoses effects in Charcot-Marie-Tooth Disease: update

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    Charcot-Marie-Tooth (CMT) disease is the most common hereditary peripheral neuropathy in humans, presenting incidence of 1:2.500 people. The distal crural weakness of the CMT causes numerous gait impairment changes, for example, velocity, length, width and cadence of the steps. Several rehabilitation resources have been proposed to manage the walking problems, among them, the use of orthoses is highlighted. The objective of this study was to present and discuss the results of studies on the effects of orthotic uses in CMT gait patterns. In this study it was used to literature update through major national/international databases (SciELO, LILACS and MEDLINE), published between the years 2006-2012. The CMT treatment consisted of physical therapy and using of assistive equipment, since there are no drugs or gene therapy able to attenuate the clinical and functional damages. This association seeks to maximize the function and improve life quality of these patients in an attempt to prevent additional injuries related to physical disability. From literature update it is possible to conclude that there is a consensus on the use of lower limb orthoses to promote the stabilization of the ankle articulation and a more functional pattern of walking, avoiding inadequate synergy of movement and reducing the risk of falls.A Doença de Charcot-Marie-Tooth (DCMT) é a neuropatia periférica hereditária mais comum em seres humanos, apresentando incidência de 1:2.500 pessoas. A fraqueza distal crural na DCMT provoca inúmeras alterações na marcha, como, por exemplo, na velocidade, no comprimento, na largura e cadência dos passos. Vários recursos em reabilitação têm sido propostos para gerenciar os problemas de deambulação, dentre eles, destaca-se a utilização de órteses. O objetivo deste estudo é apresentar e discutir os resultados de estudos sobre os efeitos da utilização de órteses nos padrões de marcha na DCMT. Neste estudo foi utilizada atualização da literatura através das principais bases de dados nacionais/internacionais (SciELO, LILACS e MEDLINE), publicados entre os anos de 2006-2012. O tratamento da DCMT consiste em fisioterapia e utilização de equipamentos de assistência, visto que ainda não há fármacos ou terapia gênica capaz de atenuar os danos clínicos e funcionais. Tal associação busca maximizar a função e melhorar a qualidade de vida desses pacientes, na tentativa de evitar agravos adicionais relativos à incapacidade física. A partir de atualização de literatura é possível concluir que existe consenso sobre a utilização de órteses nos membros inferiores para promover a estabilização das articulações do tornozelo e um padrão de deambulação mais funcional, evitando sinergias inadequadas de movimento e atenuando o risco de quedas

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

    Compressed representation of a partially defined integer function over multiple arguments

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    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Measurement of jet fragmentation into charged particles in pp and PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    Jet fragmentation in pp and PbPb collisions at a centre-of-mass energy of 2.76 TeV per nucleon pair was studied using data collected with the CMS detector at the LHC. Fragmentation functions are constructed using charged-particle tracks with transverse momenta pt > 4 GeV for dijet events with a leading jet of pt > 100 GeV. The fragmentation functions in PbPb events are compared to those in pp data as a function of collision centrality, as well as dijet-pt imbalance. Special emphasis is placed on the most central PbPb events including dijets with unbalanced momentum, indicative of energy loss of the hard scattered parent partons. The fragmentation patterns for both the leading and subleading jets in PbPb collisions agree with those seen in pp data at 2.76 TeV. The results provide evidence that, despite the large parton energy loss observed in PbPb collisions, the partition of the remaining momentum within the jet cone into high-pt particles is not strongly modified in comparison to that observed for jets in vacuum.Comment: Submitted to the Journal of High Energy Physic

    Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

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    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter

    ESCLEROSE LATERAL AMIOTRÓFICA: NOVAS POSSIBILIDADES TERAPÊUTICAS EM UM ARCABOUÇO FISIOPATOLÓGICO AINDA EM CONSTRUÇÃO

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    Esclerose Lateral Amiotrófica (ELA) é definida como uma doença neurológica progressiva e inexorável, com cerca de 80% dos casos de etiologia desconhecida. Novos medicamentos têm emergido no tratamento de doenças neurodegenerativas, inclusive na ELA, redesenhando o modelo fisiopatológico. Dentre eles, destacam-se o uso da: Edaravone, Vitamina K2, Serina, Metilcobalamina, Pirroloquinolina quinona (PQQ), Ubiquinol e Glutationa. Especificamente na ELA, alguns já foram validados em estudos randomizados-controlados. Metodologia: Atualização da literatura (PUBMED, Medline) sobre a utilização desses fármacos em doenças neurológicas degenerativas, com enfoque para a Doença do Neurônio Motor (DNM-ELA), nos idiomas Português, Inglês, Espanhol e Francês, compreendidos entre os anos de (2010-2017). Discussão: A associação desses medicamentos tem mostrado resultados positivos em inúmeras doenças neurológicas. Alguns, como, por exemplo, a Metilcobalamina e o Edaravone,exerceriam mecanismos de ação capazes de interferir no processo de depleção dos neurônios motores da ponta anterior e do feixe piramidal em pacientes com ELA. Conclusão: Seria precipitado concluir que o uso associado desses fármacos poderia modificar ou mesmo restaurar os danos às unidades motoras; entretanto, faz-se necessário destacar seus mecanismos de ação e potencial capacidade de intervir na evolução da doença, principalmente, a partir de estudos em modelos fisiopatológico que culminam na degeneração dos neurônios motores
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