Showing papers by "Rio de Janeiro State University published in 2013"

Observation of a new boson with mass near 125 GeV in pp collisions at $ \sqrt{s}=7 $ and 8 TeV

Abstract: 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 inverse femtobarns at sqrt(s) = 7 TeV, and up to 5.3 inverse femtobarns at sqrt(s) = 8 TeV. The results for five Higgs boson decay modes gamma gamma, ZZ, WW, tau tau, 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, gamma gamma and ZZ to 4 ell, 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.

Metformin: an old but still the best treatment for type 2 diabetes

Abstract: The management of T2DM requires aggressive treatment to achieve glycemic and cardiovascular risk factor goals. In this setting, metformin, an old and widely accepted first line agent, stands out not only for its antihyperglycemic properties but also for its effects beyond glycemic control such as improvements in endothelial dysfunction, hemostasis and oxidative stress, insulin resistance, lipid profiles, and fat redistribution. These properties may have contributed to the decrease of adverse cardiovascular outcomes otherwise not attributable to metformin’s mere antihyperglycemic effects. Several other classes of oral antidiabetic agents have been recently launched, introducing the need to evaluate the role of metformin as initial therapy and in combination with these newer drugs. There is increasing evidence from in vivo and in vitro studies supporting its anti-proliferative role in cancer and possibly a neuroprotective effect. Metformin’s negligible risk of hypoglycemia in monotherapy and few drug interactions of clinical relevance give this drug a high safety profile. The tolerability of metformin may be improved by using an appropiate dose titration, starting with low doses, so that side-effects can be minimized or by switching to an extended release form. We reviewed the role of metformin in the treatment of patients with type 2 diabetes and describe the additional benefits beyond its glycemic effect. We also discuss its potential role for a variety of insulin resistant and pre-diabetic states, obesity, metabolic abnormalities associated with HIV disease, gestational diabetes, cancer, and neuroprotection.

Impact of Diabetes on Cardiovascular Disease: An Update

Abstract: Cardiovascular diseases are the most prevalent cause of morbidity and mortality among patients with type 1 or type 2 diabetes The proposed mechanisms that can link accelerated atherosclerosis and increased cardiovascular risk in this population are poorly understood It has been suggested that an association between hyperglycemia and intracellular metabolic changes can result in oxidative stress, low-grade inflammation, and endothelial dysfunction Recently, epigenetic factors by different types of reactions are known to be responsible for the interaction between genes and environment and for this reason can also account for the association between diabetes and cardiovascular disease The impact of clinical factors that may coexist with diabetes such as obesity, dyslipidemia, and hypertension are also discussed Furthermore, evidence that justify screening for subclinical atherosclerosis in asymptomatic patients is controversial and is also matter of this review The purpose of this paper is to describe the association between poor glycemic control, oxidative stress, markers of insulin resistance, and of low-grade inflammation that have been suggested as putative factors linking diabetes and cardiovascular disease

Study of the Mass and Spin-Parity of the Higgs Boson Candidate via Its Decays to Z Boson Pairs

Abstract: A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3 fb^(-1), collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ channel, where both Z bosons decay to e or μ pairs, is 126.2±0.6(stat)±0.2(syst) GeV. The angular distributions of the lepton pairs in this channel are sensitive to the spin-parity of the boson. Under the assumption of spin 0, the present data are consistent with the pure scalar hypothesis, while disfavoring the pure pseudoscalar hypothesis.

Measurement of the Bs0→μ+μ- branching fraction and search for B0→μ+μ- with the CMS experiment

Abstract: Results are presented from a search for the rare decays B0s→μ+μ− and B0→μ+μ− in pp collisions at s√=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb−1, respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(B0s→μ+μ−)=(3.0+1.0−0.9)×10−9, where the uncertainty includes both statistical and systematic contributions. An excess of B0s→μ+μ− events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B0→μ+μ− an upper limit of B(B0→μ+μ−)<1.1×10−9 at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model.

Search for top-squark pair production in the single-lepton final state in pp collisions at √s=8 TeV

Abstract: This paper presents a search for the pair production of top squarks in events with a single isolated electron or muon, jets, large missing transverse momentum, and large transverse mass. The data sample corresponds to an integrated luminosity of 19.5 inverse femtobarns of pp collisions collected in 2012 by the CMS experiment at the LHC at a center-of-mass energy of sqrt(s) = 8 TeV. No significant excess in data is observed above the expectation from standard model processes. The results are interpreted in the context of supersymmetric models with pair production of top squarks that decay either to a top quark and a neutralino or to a bottom quark and a chargino. For small mass values of the lightest supersymmetric particle, top-squark mass values up to around 650 GeV are excluded.

Searches for long-lived charged particles in pp collisions at sqrt(s) = 7 and 8 TeV

Abstract: Results of searches for heavy stable charged particles produced in pp collisions at sqrt(s) = 7 and 8 TeV are presented corresponding to an integrated luminosity of 5.0 inverse femtobarns and 18.8 inverse femtobarns, respectively. Data collected with the CMS detector are used to study the momentum, energy deposition, and time-of-flight of signal candidates. Leptons with an electric charge between e/3 and 8e, as well as bound states that can undergo charge exchange with the detector material, are studied. Analysis results are presented for various combinations of signatures in the inner tracker only, inner tracker and muon detector, and muon detector only. Detector signatures utilized are long time-of-flight to the outer muon system and anomalously high (or low) energy deposition in the inner tracker. The data are consistent with the expected background, and upper limits are set on the production cross section of long-lived gluinos, scalar top quarks, and scalar tau leptons, as well as pair produced long-lived leptons. Corresponding lower mass limits, ranging up to 1322 GeV for gluinos, are the most stringent to date.

Estimated Frequency of Antiphospholipid Antibodies in Patients With Pregnancy Morbidity, Stroke, Myocardial Infarction, and Deep Vein Thrombosis: A Critical Review of the Literature

Abstract: Objective Antiphospholipid Syndrome Alliance For Clinical Trials and International Networking (APS ACTION) is an international research network devoted to conducting well-designed clinical trials in persistently antiphospholipid antibody (aPL)–positive patients. One of the first needs of APS ACTION was to know the true aPL frequency in patients with pregnancy morbidity (PM), stroke (ST), myocardial infarction (MI), and deep venous thrombosis (DVT). Methods The search for “aPL” and multiple keywords regarding the outcomes of interest was completed in PubMed. The median frequency for positive aPL tests (lupus anticoagulant, antibody against cardiolipin [aCL], and antibody against β2-glycoprotein I [anti-β2GPI]) was calculated for each outcome and was used to estimate the overall aPL frequency. Results Based on the analysis of 120 full-text papers, the overall aPL frequency was estimated as 6% for PM, 13.5% for ST, 11% for MI, and 9.5% for DVT. Limitations of the literature were that 60% of the papers were published before 2000, all 3 criteria aPL tests were performed in only 11% of the papers, 36% of papers used a low-titer aCL cutoff, anti-β2GPI cutoff was quite heterogeneous, aPL confirmation was performed in only one-fifth of papers, and the study design was retrospective in nearly half of the papers. Conclusion It is difficult to determine the frequency of a “clinically significant aPL profile” in patients with aPL-related clinical outcomes due to the lack of robust data. Our best estimates of the incidence of aPL-associated events should be confirmed with appropriately designed population studies.

Alimentos mais consumidos no Brasil: Inquérito Nacional de Alimentação 2008-2009

Abstract: OBJETIVO: Caracterizar o consumo alimentar mais frequente da populacao brasileira. METODOS: Foram analisados dados referentes ao primeiro dia de registro alimentar de 34.003 individuos com dez anos ou mais de idade que responderam ao Inquerito Nacional de Alimentacao, composto por amostra probabilistica da Pesquisa de Orcamentos Familiares 2008-2009. O padrao de consumo foi analisado segundo sexo, grupo etario, regiao e faixa de renda familiar per capita. RESULTADOS: Os alimentos mais frequentemente referidos pela populacao brasileira foram arroz (84,0%), cafe (79,0%), feijao (72,8%), pao de sal (63,0%) e carne bovina (48,7%), destacando-se tambem o consumo de sucos e refrescos (39,8%), refrigerantes (23,0%) e menor presenca de frutas (16,0%) e hortalicas (16,0%). Essa configuracao apresenta pouca variacao quando se consideram os estratos de sexo e faixa etaria; contudo, observa-se que os adolescentes foram o unico grupo etario que deixou de citar qualquer hortalica e que incluiu doces, bebida lactea e biscoitos doces entre os itens mais consumidos. Alimentos marcadamente de consumo regional incluem a farinha de mandioca no Norte e Nordeste e o cha na regiao Sul. Houve discrepâncias no consumo alimentar entre os estratos de menor e maior renda: individuos no quarto de renda mais elevada referiram sanduiches, tomate e alface e aqueles no primeiro quarto de renda citaram os peixes e preparacoes a base de peixe e farinha de mandioca entre os alimentos mais referidos. CONCLUSOES: Existe um padrao basico do consumo alimentar no Brasil que inclui entre os alimentos mais consumidos arroz, cafe, feijao, pao de sal e carne bovina, associado ao consumo regional de alguns poucos itens. Particularmente entre os adolescentes, alimentos ricos em gordura e acucar sao tambem de consumo frequente.

Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at √s = 7 TeV

Abstract: The article is the pre-print version of the final publishing paper that is available from the link below.

Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at √sNN=2.76 TeV

Abstract: The anisotropy of the azimuthal distributions of charged particles produced in √s_(NN)=2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, v_2, defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two- and four-particle cumulants, and Lee-Yang zeros. The anisotropy is presented as a function of transverse momentum (p_T), pseudorapidity (η) over a broad kinematic range, 0.3

Phylogenetic analysis reveals a high prevalence of Sporothrix brasiliensis in Feline sporotrichosis outbreaks

Abstract: Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1α) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Parana (PR, n = 4), Sao Paulo (SP, n = 3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.

Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at √s = 8 TeV

Abstract: An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb−1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, α T, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950–1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

Revised guidelines for the publication of genetic population data

Abstract: In 2000 a new policy concerning the publication of population genetic data was set up in Forensic Science International [1] with the introduction of a new section entitled ‘‘Announcement of population data’’. Subsequently in 2010 [2] a new section on ‘‘Forensic Population Genetics’’ was introduced, and recommendations were redefined. FSI: Genetics is one of the few journals still considering population genetic data for publication and we strongly believe that this policy has contributed to the dissemination of common standards in the field all over the world and also to motivate labs and people to embark in research in the area of forensic genetics. For this reason it is our intention to continue with this policy, and recently an associate editor exclusively devoted to this topic was appointed to the journal. Despite having defined a more detailed procedure for acceptance, our journal is still receiving a massive number of submissions of varying quality in this area. Therefore it has become necessary to raise the threshold regarding the acceptance of this type of publication to ensure a high standard of published data. In addition we want to improve the submission, reviewing and publication procedures, and to correct some aspects that we have detected such as the obligation to meet ethical standards in the collection of samples including informed consent and approval by ethical committees. For this reason, we have decided to publish new guidelines for the publication of population genetic data in the journal.

Measurements of differential jet cross sections in proton-proton collisions at √s=7 TeV with the CMS detector

Abstract: Measurements of inclusive jet and dijet production cross sections are presented. Data from LHC proton-proton collisions at √s=7 TeV, corresponding to 5.0 fb-1 of integrated luminosity, have been collected with the CMS detector. Jets are reconstructed up to rapidity 2.5, transverse momentum 2 TeV, and dijet invariant mass 5 TeV, using the anti-kT clustering algorithm with distance parameter R=0.7. The measured cross sections are corrected for detector effects and compared to perturbative QCD predictions at next-to-leading order, using five sets of parton distribution functions.

First Determination of UV Filters in Marine Mammals. Octocrylene Levels in Franciscana Dolphins

Abstract: Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89-782 ng·g(-1) lipid weight. Sao Paulo was found to be the most polluted area (70% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide.

Measurement of differential top-quark-pair production cross sections in pp collisions at √s = 7TeV

Abstract: Normalised differential top-quark pair production cross sections are measured in pp collisions at a centre-of-mass energy of 7 TeV at the LHC with the CMS detector using data recorded in 2011 corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurements are performed in the lepton+jets decay channels (e+jets and mu+jets) and the dilepton decay channels (oppositely charged ee, mu mu, and e mu). The t t-bar differential cross section is measured as a function of kinematic properties of the final-state charged leptons and jets associated to b quarks, as well as those of the top quarks and the t t-bar system. The data are compared with several predictions from perturbative QCD calculations up to approximate next-to-next-to-leading-order precision. No significant deviations from the standard model are observed.

Baseline predictors of systemic lupus erythematosus flares: data from the combined placebo groups in the phase III belimumab trials.

Abstract: Objective To identify predictors of moderate-to-severe systemic lupus erythematosus (SLE) flare in 562 patients treated with standard therapy alone in phase III belimumab trials, and to evaluate the impact of standard therapies on preventing flares. Methods Post hoc analysis assessed baseline demographics, disease activity, and biomarkers in patients with and those without flare at treatment weeks 24 and 52. Severe flare was defined by the modified SLE Flare Index (SFI) and the development of any new British Isles Lupus Assessment Group (BILAG) A domain score. Severe and moderate flare was defined by development of 1 new BILAG A domain score or 2 new BILAG B domain scores. Baseline characteristics associated with a ≥10% absolute difference or a ≥50% increase in flare rates were considered predictive. Results Frequencies of flares over 52 weeks according to the SFI, any new BILAG A domain score, and 1 new BILAG A domain score or 2 new BILAG B domain scores were 23.7%, 23.1%, and 32.0%, respectively. Flare predictors by univariate analysis on all 3 indices at weeks 24 and 52 were a score ≥12 on the Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index (SELENA–SLEDAI); anti–double-stranded DNA (anti-dsDNA) positivity; proteinuria (≥0.5 gm/24 hours); BILAG renal, vasculitic, and hematologic scores; elevated C-reactive protein levels; and B lymphocyte stimulator (BLyS) levels ≥2 ng/ml. Independent predictors by multivariate analysis at week 52 were SELENA–SLEDAI and/or BILAG renal involvement and anti-dsDNA ≥200 IU/ml (on all 3 indices); SELENA–SLEDAI and/or BILAG neurologic and vasculitic involvement (on 2 indices: any new BILAG A domain score and 1 new BILAG A domain score or 2 new BILAG B domain scores); BLyS levels ≥2 ng/ml (on 2 indices: the SFI and 1 new BILAG A domain score or 2 new BILAG B domain scores); and low C3 level (on the SFI). Baseline medications did not significantly decrease or increase moderate-to-severe SLE flare risk. Conclusion Patients who were receiving standard SLE therapy and had renal, neurologic, or vasculitic involvement, elevated anti-dsDNA or BLyS levels, or low C3 had increased risk of clinically meaningful flare over 1 year. Hydroxychloroquine use was not predictive.

Measurement of the differential and double-differential Drell-Yan cross sections in proton-proton collisions at s√ = 7 TeV

Abstract: Measurements of the differential and double-differential Drell-Yan cross sections are presented using an integrated luminosity of 4.5 (4.8) fb−1 in the dimuon (dielectron) channel of proton-proton collision data recorded with the CMS detector at the LHC at s√ = 7 TeV. The measured inclusive cross section in the Z-peak region (60–120 GeV) is σ(ll) = 986.4 ± 0.6 (stat.) ± 5.9 (exp. syst.) ± 21.7 (th. syst.) ± 21.7 (lum.) pb for the combination of the dimuon and dielectron channels. Differential cross sections dσ/dm for the dimuon, dielectron, and combined channels are measured in the mass range 15 to 1500 GeV and corrected to the full phase space. Results are also presented for the measurement of the double-differential cross section d2σ/dm d|y| in the dimuon channel over the mass range 20 to 1500 GeV and absolute dimuon rapidity from 0 to 2.4. These measurements are compared to the predictions of perturbative QCD calculations at next-to-leading and next-to-next-to-leading orders using various sets of parton distribution functions.

General dissipation coefficient in low-temperature warm inflation

Abstract: In generic particle physics models, the inflaton field is coupled to other bosonic and fermionic fields that acquire large masses during inflation and may decay into light degrees of freedom. This leads to dissipative effects that modify the inflationary dynamics and may generate a nearly-thermal radiation bath, such that inflation occurs in a warm rather than supercooled environment. In this work, we perform a numerical computation and obtain expressions for the associated dissipation coefficient in supersymmetric models, focusing on the regime where the radiation temperature is below the heavy mass threshold. The dissipation coefficient receives contributions from the decay of both on-shell and off-shell degrees of freedom, which are dominant for small and large couplings, respectively, taking into account the light field multiplicities. In particular, we find that the contribution from on-shell decays, although Boltzmann-suppressed, can be much larger than that of virtual modes, which is bounded by the validity of a perturbative analysis. This result opens up new possibilities for realizations of warm inflation in supersymmetric field theories.