1000 resultados para Conservatório Nacional de Lisboa


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We report the measurement of the transverse momentum dependence of inclusive J/psi polarization in p + p collisions at root s = 200 GeV performed by the PHENIX Experiment at the Relativistic Heavy Ion Collider. The J/psi polarization is studied in the helicity, Gottfried-Jackson, and Collins-Soper frames for p(T) < 5 GeV/c and vertical bar y vertical bar < 0.35. The polarization in the helicity and Gottfried-Jackson frames is consistent with zero for all transverse momenta, with a slight (1.8 sigma) trend towards longitudinal polarization for transverse momenta above 2 GeV/c. No conclusion is allowed due to the limited acceptance in the Collins-Soper frame and the uncertainties of the current data. The results are compared to observations for other collision systems and center of mass energies and to different quarkonia production models.

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PHENIX has measured the e(+)e(-) pair continuum in root s(NN) = 200 GeV Au+Au and p+p collisions over a wide range of mass and transverse momenta. The e(+)e(-) yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate-mass region, between the masses of the phi and the J/psi meson, the yield is consistent with expectations from correlated c (c) over bar production, although other mechanisms are not ruled out. In the low-mass region, below the phi, the p+p inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of 4.7 +/- 0.4(stat) +/- 1.5(syst) +/- 0.9(model). At low mass (m(ee) < 0.3 GeV/c(2)) and high p(T) (1 < p(T) < 5 GeV/c) an enhanced e(+)e(-) pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the p+p is exponential in p(T), with inverse slope T = 221 +/- 19(stat) +/- 19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) similar or equal to 300-600 MeV at times of 0.6-0.15 fm/c after the collision are in qualitative agreement with the direct photon data in Au+Au. For low p(T) < 1 GeV/c the low-mass region shows a further significant enhancement that increases with centrality and has an inverse slope of T similar or equal to 100 MeV. Theoretical models underpredict the low-mass, low-p(T) enhancement.

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Pair correlations between large transverse momentum neutral pion triggers (p(T) = 4-7 GeV/c) and charged hadron partners (p(T) = 3-7 GeV/c) in central (0%-20%) and midcentral (20%-60%) Au + Au collisions at root s(NN) = 200 GeV are presented as a function of trigger orientation with respect to the reaction plane. The particles are at larger momentum than where jet shape modifications have been observed, and the correlations are sensitive to the energy loss of partons traveling through hot densematter. An out-of-plane trigger particle produces only 26 +/- 20% of the away-side pairs that are observed opposite of an in-plane trigger particle for midcentral (20%-60%) collisions. In contrast, near-side jet fragments are consistent with no suppression or dependence on trigger orientation with respect to the reaction plane. These observations are qualitatively consistent with a picture of little near-side parton energy loss either due to surface bias or fluctuations and increased away-side parton energy loss due to a long path through the medium. The away-side suppression as a function of reaction-plane angle is shown to be sensitive to both the energy loss mechanism and the space-time evolution of heavy-ion collisions.

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We report the observation at the Relativistic Heavy Ion Collider of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron (gamma-h) background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics, making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I(AA), in central Au+Au collisions, is 0.32 +/- 0.12(stat)+/- 0.09(syst) for hadrons of 3 < p(T)(h)< 5 in coincidence with photons of 5 < p(T)(gamma)< 15 GeV/c. The suppression is comparable to that observed for high-p(T) single hadrons and dihadrons. The direct photon associated yields in p+p collisions scale approximately with the momentum balance, z(T)equivalent to p(T)(h)/p(T)(gamma), as expected for a measurement of the away-side parton fragmentation function. We compare to Au+Au collisions for which the momentum balance dependence of the nuclear modification should be sensitive to the path-length dependence of parton energy loss.

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The PHENIX experiment presents results from the RHIC 2006 run with polarized p + p collisions at root s = 62.4 GeV, for inclusive pi(0) production at midrapidity. Unpolarized cross section results are measured for transverse momenta p(T) = 0.5 to 7 GeV/c. Next-to-leading order perturbative quantum chromodynamics calculations are compared with the data, and while the calculations are consistent with the measurements, next-to-leading logarithmic corrections improve the agreement. Double helicity asymmetries A(LL) are presented for p(T) = 1 to 4 GeV/c and probe the higher range of Bjorken x of the gluon (x(g)) with better statistical precision than our previous measurements at root s = 200 GeV. These measurements are sensitive to the gluon polarization in the proton for 0.06 < x(g) < 0.4.

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We report on the event structure and double helicity asymmetry (A(LL)) of jet production in longitudinally polarized p + p collisions at root s = 200 GeV. Photons and charged particles were measured by the PHENIX experiment at midrapidity vertical bar eta vertical bar < 0.35 with the requirement of a high-momentum (> 2 GeV/c) photon in the event. Event structure, such as multiplicity, p(T) density and thrust in the PHENIX acceptance, were measured and compared with the results from the PYTHIA event generator and the GEANT detector simulation. The shape of jets and the underlying event were well reproduced at this collision energy. For the measurement of jet A(LL), photons and charged particles were clustered with a seed-cone algorithm to obtain the cluster pT sum (p(T)(reco)). The effect of detector response and the underlying events on p(T)(reco) was evaluated with the simulation. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order and perturbative quantum chromodynamics jet production cross section. For 4< p(T)(reco) < 12 GeV/c with an average beam polarization of < P > = 49% we measured Lambda(LL) = -0.0014 +/- 0.0037(stat) at the lowest p(T)(reco) bin (4-5 GeV= c) and -0.0181 +/- 0.0282(stat) at the highest p(T)(reco) bin (10-12 GeV= c) with a beam polarization scale error of 9.4% and a pT scale error of 10%. Jets in the measured p(T)(reco) range arise primarily from hard-scattered gluons with momentum fraction 0: 02 < x < 0: 3 according to PYTHIA. The measured A(LL) is compared with predictions that assume various Delta G(x) distributions based on the Gluck-Reya-Stratmann-Vogelsang parameterization. The present result imposes the limit -a.1 < integral(0.3)(0.02) dx Delta G(x, mu(2) = GeV2) < 0.4 at 95% confidence level or integral(0.3)(0.002) dx Delta G(x, mu(2) = 1 GeV2) < 0.5 at 99% confidence level.

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Transverse momentum distributions and yields for pi(+/-), K(+/-), p, and (p) over bar in p + p collisions at root s = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra for comparisons with identified particle spectra in heavy ion collisions at RHIC. We present the inverse slope parameter T(inv), mean transverse momentum < p(T)>, and yield per unit rapidity dN/dy at each energy, and compare them to other measurements at different root s in p + p and p + (p) over bar collisions. We also present the scaling properties such as m(T) scaling and x(T) scaling on the p(T) spectra between different energies. To discuss the mechanism of the particle production in p + p collisions, the measured spectra are compared to next-to-leading-order or next-to-leading-logarithmic perturbative quantum chromodynamics calculations.

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The effect of conversion from forest-to-pasture upon soil carbon stocks has been intensively discussed, but few studies focus on how this land-use change affects carbon (C) distribution across soil fractions in the Amazon basin. We investigated this in the 20 cm depth along a chronosequence of sites from native forest to three successively older pastures. We performed a physicochemical fractionation of bulk soil samples to better understand the mechanisms by which soil C is stabilized and evaluate the contribution of each C fraction to total soil C. Additionally, we used a two-pool model to estimate the mean residence time (MRT) for the slow and active pool C in each fraction. Soil C increased with conversion from forest-to-pasture in the particulate organic matter (> 250 mu m), microaggregate (53-250 mu m), and d-clay (< 2 mu m) fractions. The microaggregate comprised the highest soil C content after the conversion from forest-to-pasture. The C content of the d-silt fraction decreased with time since conversion to pasture. Forest-derived C remained in all fractions with the highest concentration in the finest fractions, with the largest proportion of forest-derived soil C associated with clay minerals. Results from this work indicate that microaggregate formation is sensitive to changes in management and might serve as an indicator for management-induced soil carbon changes, and the soil C changes in the fractions are dependent on soil texture.

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Incomplete revascularization is associated with worse long-term outcomes. Autologous bone marrow cells (BMC) have recently been tested in patients with severe coronary artery disease. We tested the hypothesis that intramyocardial injection of autologous BMC increases myocardial perfusion in patients undergoing incomplete coronary artery bypass grafting (CABG). Twenty-one patients (19 men), 59 +/- 7 years old, with limiting angina and multivessel coronary artery disease (CAD), not amenable to complete CABG were enrolled. BMC were obtained prior to surgery, and the lymphomonocytic fraction separated by density gradient centrifugation. During surgery, 5 mL containing 2.1 +/- 1.3 x 10(8) BMC (CD34+ = 0.8 +/- 0.3%) were injected in the ischemic non-revascularized myocardium. Myocardial perfusion was assessed by magnetic resonance imaging (MRI) at baseline and 1 month after surgery. The increase in myocardial perfusion was compared between patients with < 50% (group A, n = 11) with that of patients with > 50% (group B, n = 10) of target vessels (stenosis a parts per thousand yenaEuro parts per thousand 70%) successfully bypassed. Injected myocardial segments included the inferior (n = 12), anterior (n = 7), and lateral (n = 2) walls. The number of treated vessels (2.3 +/- 0.8) was significantly smaller than the number of target vessels (4.2 +/- 1.0; P < 0.0001). One month after surgery, cardiac MRI showed a similar reduction (%) in the ischemic score of patients in group A (72.5 +/- 3.2), compared to patients in group B (78.1 +/- 3.2; P = .80). Intramyocardial injection of autologous BMC may help increase myocardial perfusion in patients undergoing incomplete CABG, even in those with fewer target vessels successfully treated. This strategy may be an adjunctive therapy for patients suffering from a more advanced (diffuse) CAD not amenable for complete direct revascularization.

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O Compromisso Nacional para Aperfei??oar as Condi????es de Trabalho na Cana-de-A????car, firmado pelo Governo Federal e entidades de trabalhadores e empres??rios do setor sucroenerg??tico, ?? resultado de uma experi??ncia in??dita no pa??s de negocia????o tripartite para enfrentar o desafio de melhorar as condi????es de vida e trabalho no cultivo manual da cana-de-a????car. Por meio de uma Mesa de Di??logo, sob a coordena????o da Secretaria-Geral da Presid??ncia da Rep??blica, foi constru??do um acordo hist??rico para valorizar e disseminar as melhores pr??ticas trabalhistas na lavoura da cana, evidenciando a import??ncia do di??logo social na elabora????o das Pol??ticas P??blicas. Atrav??s da ades??o volunt??ria das empresas ao Compromisso, da divulga????o das boas pr??ticas empresariais e do cadastro positivo formado pelo selo ???Empresa Compromissada???, conferido ap??s verifica????o in loco de auditoria independente, a iniciativa induz os demais atores do setor a aderir ao Compromisso e adotar as boas pr??ticas trabalhistas

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Implementa????o de modelo gerencial de compras governamentais por meio do Sistema de Registro de Pre??os (SRP), chamado Registro de Pre??os Nacional (RPN), no qual s??o elaboradas especifica????es de materiais, em atendimento ??s demandas dos alunos do sistema de educa????o b??sica brasileiro (estados e munic??pios), proporcionando adequa????o ??s reais necessidades de seus usu??rios e maior qualidade. A ferramenta ?? baseada em arranjo institucional entre entes p??blicos e privados, visando a padroniza????o, adequa????o e qualidade dos produtos adquiridos. Dessa forma, o governo federal vale-se do conhecimento dos seus diversos ??rg??os e t??cnicos para realizar um ??nico processo de compra para todo o pa??s sem, necessariamente, precisar efetivar qualquer contrato, disponibilizando apenas o registro de pre??os, obtido por meio de preg??o eletr??nico. Assim, o processo de aquisi????o se torna menos burocr??tico e oneroso, primando pelos princ??pios da legalidade, efici??ncia e economicidade

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O Pacto Nacional pelo Enfrentamento da Viol??ncia contra as Mulheres visa descentralizar a????es por meio de acordo federativo entre o governo federal e os governos dos estados e dos munic??pios brasileiros. Participam do pacto a Secretaria Especial de Pol??ticas para as Mulheres da Presid??ncia da Rep??blica (SPM/PR), organiza????es da sociedade civil, e outros parceiros do governo federal. Com o objetivo principal de reduzir os ??ndices de viol??ncia contra as mulheres, o pacto ?? composto por quatro grandes eixos: Implementa????o da Lei Maria da Penha e Fortalecimento dos Servi??os Especializados de Atendimento; Prote????o dos Direitos Sexuais e Reprodutivos e Enfrentamento da Feminiza????o da Aids; Combate ?? Explora????o Sexual de Meninas e Adolescentes e ao Tr??fico de Mulheres; e Promo????o dos Direitos Humanos das Mulheres em Situa????o de Pris??o. Desde 2008, os seguintes estados j?? aderiram ao Pacto: Acre, Bahia, Cear??, Esp??rito Santo, Goi??s, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Par??, Pernambuco, Rio de Janeiro, S??o Paulo, Tocantins, Alagoas, Amap??, Para??ba e Sergipe

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O portal da ENSP foi criado como ferramenta de apoio ?? gest??o do conhecimento e para garantir a qualidade da informa????o gerada e organizada pela institui????o. Oferece um conjunto de aplicativos que consolida, gerencia, analisa e distribui informa????es, n??o s?? internamente, mas tamb??m para o p??blico externo. A integra????o desses aplicativos permite que os usu??rios possam ter um ??nico ponto de acesso ??s informa????es, permitindo ler, gravar e atualizar dados pessoais e institucionais. Nessa vers??o do portal da ENSP, os usu??rios devem-se cadastrar para ter acesso a alguns servi??os, como postagem de documentos na Biblioteca Multim??dia, coment??rios no Informe ENSP e participa????o em redes sociais, documentos internos e informa????es departamentais

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O Sistema Nacional de Informa????es de Defesa do Consumidor integra Procons de 23 estados brasileiros e do Distrito Federal. ?? um sistema que permite o registro de demandas individuais de consumidores, bem como a gest??o dos procedimentos que tratam essas demandas. O Sindec consolida os registros em bases locais e forma um banco nacional de informa????es sobre problemas enfrentados por consumidores. Essas informa????es podem ser consultadas por consumidores, pelos Procons integrados e por toda a sociedade, por meio do s??tio www.mj.gov.br/sindec. O Sindec re??ne informa????es de mais de 80 Procons (entre estaduais, municipais e do Distrito Federal), est?? presente em mais de 110 cidades de todas as regi??es brasileiras e consolida registros de demandas de mais de 2 milh??es de consumidores contra mais de 10 mil fornecedores

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A Rede Nacional de Altos Estudos em Seguran??a P??blica (Renaesp) ?? um projeto de educa????o permanente, democr??tica e qualificada, promovido a partir da parceria com institui????es de ensino superior ??? que recebem investimentos para realizar cursos nas modalidades presencial e a dist??ncia ??? para a promo????o de p??s-gradua????o na ??rea de seguran??a p??blica. O objetivo principal da rede ?? democratizar o acesso dos profissionais de seguran??a p??blica ??? sem distin????o hier??rquica ??? aos processos de aprendizagem e aperfei??oamento profissional. Busca-se difundir entre esses profissionais e as institui????es em que trabalham o conhecimento e a capacidade cr??tica necess??rios ?? constru????o de um novo modo de fazer seguran??a p??blica, comprometido com a cidadania e os direitos humanos. A iniciativa destina-se aos policiais federais, rodovi??rios federais, policiais civis e militares, agentes penitenci??rios, peritos criminais e guardas municipais. Presente em 26 estados, a Renaesp j?? capacitou 5.250 profissionais