Search for the associated production of the Higgs boson with a top-quark pair

A search for the standard model Higgs boson produced in association with a top-quark pair t t ¯ H (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb −1 and 19.7 fb −1 collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H → hadrons, H → photons, and H → leptons. The results are characterized by an observed t t ¯ H tt¯H signal strength relative to the standard model cross section, μ = σ/σ SM ,under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is μ = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV

Measurements of the t(t)Overbar charge asymmetry using the dilepton decay channel in pp collisions at root s=7 TeV

The tt¯ charge asymmetry in proton-proton collisions at s√ = 7 TeV is measured using the dilepton decay channel (ee, e μ , or μμ ). The data correspond to a total integrated luminosity of 5.0 fb −1 , collected by the CMS experiment at the LHC. The tt and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be A C = −0 . 010 ± 0 . 017 (stat . ) ± 0 . 008 (syst . ) and AlepC = 0 . 009 ± 0 . 010 (stat . ) ± 0 . 006 (syst . ). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the tt¯ system. All measurements are consistent with the expectations of the standard model

Measurement of prompt Jψ\psi pair production in pp collisions at \sqrt s = 7 Tev

Production of prompt J/ ψ meson pairs in proton-proton collisions at s s√ = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb −1 . The two J/ ψ mesons are fully reconstructed via their decays into μ + μ − pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ ψ transverse momentum ( p T J/ ψ ) and rapidity (| y J/ ψ |): | y J/ ψ | 6.5 GeV/ c ; 1.2 4.5 GeV/ c . The total cross section, assuming unpolarized prompt J/ ψ pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/ ψ polarization imply modifications to the cross section ranging from −31% to +27%

Electrocardiographic profile of guinea pig heart submitted to Ginkgo biloba extract and its terpenoids

Electrocardiographic effects produced by Ginkgo biloba extract (EGb) and by ginkgolides A (GA) and B (GB), and bilobalide (BB) were investigated in guinea pig heart mounted in Langendorff apparatus (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Electrocardiographic parameters were evaluated in the conditions: 1) control with Tyrode and DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) or BB (n=6), and 3) washout. The results showed that 0.1 and 1.0 mg/ml of EGb do not change the electrocardiographic parameters. However, 10 mg/ml of EGb increased the PR interval (PRi) at 21% (p<0.001). This increase was also observed for 50 mM GA (20%, p<0.001) and 70 mM BB (13%, p<0.001), which indicates Ca2+ channel block. However, the 50 mM GB reduced the PRi at 11 % (p<0.001). The GA (23%, p<0.001), GB (16%, p<0.001), and BB (40%, p<0.001) reduced the QT interval (QTi), which suggests the activation of the potassium channel. However, EGb increased QTi (6%, p<0.001). The EGb (28%, p<0.05) and GB (13%, p<0.05) reduced the heart rate. Atrioventricular (AV) block was observed with EGb, GA, and BB. We can conclude that EGb and its terpenoids alter the ECG parameters inducing AV block, which indicates possible arrhythmogenic potential

Critérios de seleção para características de crescimento em bovinos da raça Nelore Selection criteria for growth traits in Nellore cattle

Foram utilizados 28.050 registros de bovinos Nelore para estabelecer critérios de seleção para bovinos de corte, considerando as características ganho médio diário do nascimento à desmama (GND), dias para o animal ganhar 160kg do nascimento à desmama (D160), ganho médio diário da desmama ao sobreano (D240) e dias para o animal ganhar 240kg da desmama ao sobreano (D240). As estimativas de herdabilidade foram: GND, 0,20; D160, 0,19; GDS, 0,07; e D240, 0,03. Considerando os efeitos maternos, a herdabilidade da característica D160 foi 0,16 e a da GND, 0,06. Verificou-se correlação genética alta e negativa entre GND e D160 (-0,95) e negativas entre efeito genético direto do GND e efeito genético materno da mesma característica (-0,24) e entre efeitos genéticos diretos do GND e do D160 (-0,15). Houve associação positiva entre o efeito genético materno de GND e direto de GDS (0,33), e correlação nula entre o efeito genético direto das características D160 e D240. Conclui-se que a velocidade de crescimento pode ser modificada adotando-se como critério de seleção qualquer uma das duas características do período pré-desmama, apesar deles não selecionarem os mesmos animais, principalmente se na adoção do critério forem considerados os efeitos maternos no período pré-desmama e os efeitos genéticos diretos no período pós-desmama. As magnitudes das correlações estimadas entre as características nos períodos pré e pós-desmama foram baixas, indicando que os animais poderiam ser selecionados no período pré-desmama, independente do critério de seleção adotado na pós-desmama.Data records of 28,050 animals from Nellore breed were used to compare selection criteria for beef cattle based on weight gain from birth to weaning (GBW), number of days to gain 160kg during the pre-weaning períod (D160), daily weight gain from weaning to 18 months (GW18) and number of days to gain 240kg during the pos-weaning period (D240). Direct heritability estimates of GBW (.20) and D160 (.19) were similar while the direct heritability estimate of GW18 (.07) was larger than D240 (.03). Maternal heritability estimate of D160 (.16) was larger than maternal heritability of GBW (.06). High and negative correlation (-.95) was observed between GBW and D160. The association between maternal effect of GBW and direct effect of GW18 was positive (.33) while null correlation estimate betweeen D160 and D240 was observed for direct genetic effect. According to the estimated genetic parameters growth rate can be changed by both selection criteria (BBW and D160), during the pre-weaning period, although both selection criteria would not select the same animals, mainly if the selection criteria were based on maternal genetic effect during pre-weaning period and the direct genetic effect during the pos-weaning period. Maternal effect was not an important selection criterion for the studied traits. The low estimated correlations between pairs of traits for the pre and pos-weaning periods, also suggest that the selection criterion for each period, based on the studied traits, can be chosen independently