890 resultados para Porteous, G. Thomas, Jr., 1946-


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Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a flipflop phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites.

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A search for new physics is performed using events with isolated same-sign leptons and at least two bottom-quark jets in the final state. Results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 8 TeV with the CMS detector and corresponding to an integrated luminosity of 10.5 fb-1. No excess above the standard model background is observed. Upper limits are set on the number of events from non-standard-model sources and are used to constrain a number of new physics models. Information on acceptance and efficiencies is also provided so that the results can be used to confront an even broader class of new physics models. © 2013 CERN for the benefit of the CMS collaboration.

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A detailed description is reported of the analysis used by the CMS Collaboration in the search for the standard model Higgs boson in pp collisions at the LHC, which led to the observation of a new boson. The data sample corresponds to integrated luminosities up to 5.1 fb-1 at √=7 TeV, and up to 5.3 fb-1 at √ s=8 TeV. The results for five Higgs boson decay modes γγ, ZZ, WW, ττ, and bb, which show a combined local significance of 5 standard deviations near 125 GeV, are reviewed. A fit to the invariant mass of the two high resolution channels, γγ and ZZ → 4ℓ, gives a mass estimate of 125.3 ± 0.4 (stat.) ± 0.5 (syst.) GeV. The measurements are interpreted in the context of the standard model Lagrangian for the scalar Higgs field interacting with fermions and vector bosons. The measured values of the corresponding couplings are compared to the standard model predictions. The hypothesis of custodial symmetry is tested through the measurement of the ratio of the couplings to the W and Z bosons. All the results are consistent, within their uncertainties, with the expectations for a standard model Higgs boson. [Figure not available: see fulltext.] © 2013 CERN for the benefit of the CMS collaboration.

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A dieta de Micoureus demerarae (Thomas, 1905) foi estudada em bosques de mangue e terra firme através de amostras estomacais e fecais. O número de indivíduos capturados foi inversamente proporcional à disponibilidade de frutos e insetos, sendo Coleoptera e Hemiptera as ordens de artrópodes mais consumidos e Passifloraceae e Arecaceae os frutos mais ingeridos. Desse modo, tanto a maior variabilidade de frutos como a alta produção destes durante a estação seca, parecem explicar o aumento da captura desses animais nos bosques de terra firme, dos quais são originalmente provenientes. Os itens alimentares sugerem que esta espécie possui uma dieta do tipo onívora, independentemente da sazonalidade ou distribuição dos recursos disponíveis.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Thomas Smithwick Gettys (1912-2003) was a lawyer and U.S. Representative for the Fifth Congressional District of South Carolina. The Thomas Smithwick Gettys Papers consist of reports, resolutions, correspondence, news releases, government publications, and newspaper clippings, relating to Getty’s efforts to enlarge and develop the Cowpens Battlefield Site of Cherokee County, South Carolina. Correspondents include Ernest Hollings, Donald Russell, John P. Saylor, W.S. Stuckey, Jr., Roy A. Taylor, Mark W. Clark, Wayne Aspinall, and Stewart Udall.

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Wetland ecology is a relatively new field that developed from an initial interest in a few direct benefits that wetlands provide to society. Consequently, much early scientific work was stimulated by economic returns from specific wetland services, such as production of peat and provision of habitat for economically valuable wildlife (e.g., waterfowl and furbearers). Over time, societal interest in wetlands broadened, and these unique habitats are now valued for many additional services, including some that bear non market value. Common examples include carbon sequestration, flood reduction, water purification, and aesthetics. The increased recognition of the importance of wetlands has generated a diversity of job opportunities in wetland ecology and management. Despite the increased knowledge base and enhanced job market, I am not aware of any institutions that offer specialty degrees in this new discipline. Indeed, relatively few institutions offer specific wetland ecology classes, with Arnold G. van der Valk and a few of his peers at other universities being notable exceptions.

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Clyomys Thomas, 1916 is a semifossorial rodent genus of spiny rats represented by only one species, C. laticeps, which inhabits the tropical savannas and grasslands of central Brazil and eastern Paraguay. Here we describe a new karyotype of C. laticeps found in populations of Emas National Park, Goias state, Brazil. The four analyzed specimens had a diploid number (2n) of 32 and a fundamental autosome number (FN) of 54. Cytogenetic data include conventional staining, CBG and GTG-banding. The karyotype presents 12 meta/submetacentric pairs (1 to 12) and 3 pairs of acrocentrics (13 to 15) with gradual decrease in size. The X chromosome is a medium submetacentric and the Y is a medium acrocentric. The semifossorial habits together with habitat specificity could have contributed to the karyological variations found on this genus.

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Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent rho(0) photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent rho(0) photoproduction with nuclear breakup is 10.5 +/- 1.5 +/- 1.6mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is 4.4 +/- 0.6, less than is predicted by most theoretical models. It is, however, proportionally much larger than the previously observed 15% +/- 55% increase between 130 GeV and 200 GeV.

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Two-particle azimuthal (Delta phi) and pseudorapidity (Delta eta) correlations using a trigger particle with large transverse momentum (p(T)) in d+Au, Cu+Cu, and Au+Au collisions at root s(NN) = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is separated into a jet-like component, narrow in both Delta phi and Delta eta, and the ridge, narrow in Delta phi but broad in Delta eta. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated p(T). The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at root s(NN) = 200 GeV, is also found in Cu+Cu collisions and in collisions at root s(NN) = 62.4 GeV, but is found to be substantially smaller at root s(NN) = 62.4 GeV than at root s(NN) = 200 GeV for the same average number of participants (< N-part &gt;). Measurements of the ridge are compared to models.

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This paper reports results for directed flow v(1) and elliptic flow v(2) of charged particles in Cu + Cu collisions at root s(NN) = 22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0-60% most central collisions, using charged particles observed in the STAR detector. Our measurements extend to 22.4-GeV Cu + Cu collisions the prior observation that v1 is independent of the system size at 62.4 and 200 GeV and also extend the scaling of v(1) with eta/y(beam) to this system. The measured v(2)(p(T)) in Cu + Cu collisions is similar for root s(NN) throughout the range 22.4 to 200 GeV. We also report a comparison with results from transport model (ultrarelativistic quantum molecular dynamics and multiphase transport model) calculations. The model results do not agree quantitatively with the measured v(1)(eta), v(2)(p(T)), and v(2)(eta).

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We report transverse momentum (p(T) <= 15 GeV/c) spectra of pi(+/-), K-+/-, p, (p) over bar, K-0(S), and rho(0) at midrapidity in p + p and Au + Au collisions at root s(NN) = 200 GeV. Perturbative QCD calculations are consistent with pi(+/-) spectra in p + p collisions but do not reproduce K and p((p) over bar) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au + Au at p(T) &gt;= 8 GeV/c are measured to be similar to the p + p results, despite the expected Casimir effect for parton energy loss.

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We report new STAR measurements of midrapidity yields for the Lambda, (Lambda) over bar, K-S(0), Xi(-), (Xi) over bar (+), Omega(-), (Omega) over bar (+) particles in Cu + Cu collisions at root s(NN) = 200 GeV, and midrapidity yields for the Lambda, (Lambda) over bar, K-S(0) particles in Au + Au at root s(NN) = 200 GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu + Cu collisions than in Au + Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

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Background: Heavy-flavor production in p + p collisions is a good test of perturbative-quantum-chromodynamics (pQCD) calculations. Modification of heavy-flavor production in heavy-ion collisions relative to binary-collision scaling from p + p results, quantified with the nuclear-modification factor (R-AA), provides information on both cold-and hot-nuclear-matter effects. Midrapidity heavy-flavor R-AA measurements at the Relativistic Heavy Ion Collider have challenged parton-energy-loss models and resulted in upper limits on the viscosity-entropy ratio that are near the quantum lower bound. Such measurements have not been made in the forward-rapidity region. Purpose: Determine transverse-momentum (p(T)) spectra and the corresponding R-AA for muons from heavy-flavor meson decay in p + p and Cu + Cu collisions at root s(NN) = 200 GeV and y = 1.65. Method: Results are obtained using the semileptonic decay of heavy-flavor mesons into negative muons. The PHENIX muon-arm spectrometers measure the p(T) spectra of inclusive muon candidates. Backgrounds, primarily due to light hadrons, are determined with a Monte Carlo calculation using a set of input hadron distributions tuned to match measured-hadron distributions in the same detector and statistically subtracted. Results: The charm-production cross section in p + p collisions at root s = 200 GeV, integrated over p(T) and in the rapidity range 1.4 < y < 1.9, is found to be d(sigma e (e) over bar)/dy = 0.139 +/- 0.029 (stat)(-0.058)(+0.051) (syst) mb. This result is consistent with a perturbative fixed-order-plus-next-to-leading-log calculation within scale uncertainties and is also consistent with expectations based on the corresponding midrapidity charm-production cross section measured by PHENIX. The R-AA for heavy-flavor muons in Cu + Cu collisions is measured in three centrality bins for 1 < p(T) < 4 GeV/c. Suppression relative to binary-collision scaling (R-AA < 1) increases with centrality. Conclusions: Within experimental and theoretical uncertainties, the measured charm yield in p + p collisions is consistent with state-of-the-art pQCD calculations. Suppression in central Cu + Cu collisions suggests the presence of significant cold-nuclear-matter effects and final-state energy loss.