The Supernova Gamma-Ray Burst Connection

The chief distinction between ordinary supernovae and long-soft gamma-ray bursts (GRBs) is the degree of differential rotation in the inner several solar masses when a massive star dies, and GRBs are rare mainly because of the difficulty achieving the necessary high rotation rate. Models that do provide the necessary angular momentum are discussed, with emphasis on a new single star model whose rapid rotation leads to complete mixing on the main sequence and avoids red giant formation. This channel of progenitor evolution also gives a broader range of masses than previous models, and allows the copious production of bursts outside of binaries and at high redshifts. However, even the production of a bare helium core rotating nearly at break up is not, by itself, a sufficient condition to make a gamma-ray burst. Wolf-Rayet mass loss must be low, and will be low in regions of low metallicity. This suggests that bursts at high redshift (low metallicity) will, on the average, be more energetic, have more time structure, and last longer than bursts nearby. Every burst consists of three components: a polar jet (~0.1 radian), high energy, subrelativistic mass ejection (~1 radian), and low velocity equatorial mass that can fall back after the initial explosion. The relative proportions of these three components can give a diverse assortment of supernovae and high energy transients whose properties may vary with redshift.Comment: 10 pages, to appear in AIP Conf. Proc. "Gamma Ray Bursts in the Swift Era", Eds. S. S. Holt, N. Gehrels, J. Nouse

EFEITO DA MONENSINA SÓDICA NO CONSUMO DE ALIMENTOS E pH RUMINAL EM OVINOS

The main aim of the present research work was the study of the effects of the ionophore sodium monensin on feed voluntary intake and on the pH of the ruminal liquid in sheep. Four Santa Inês non pregnant, non lactating and rumen-cannulated lambs were used within a Latin square experimental design with four treatments: T1 - 0; T2 - 25; T3 - 50 and T4 - 75 mg monensin/animal/day. Feed, dry matter intake and ruminal fluid pH were evaluated. Sampling of ruminal fluid for pH determination was carried out at 0, 2, 4, 6 and 8 hours after feeding. According to the analysis of variance no significant values were found for intake of diet and dry matter, in regard to the levels of monensin. No siginificant effect in the average values of ruminal pH of each treatment and in the treatment x time interaction were found, the pH values being considered normal. There was a statistic difference in regard to the values found along the day. The voluntary feed intake and ruminal pH had not been influenced by the addition of sodium monensin in the diet of the sheep, the pH values remaining elevated, characterizing a good evironment of ruminal fermentation.Objetivou-se avaliar os efeitos da adição da monensina sódica no consumo de alimentos e no pH do líquido ruminal em ovinos. Foram utilizadas quatro ovelhas da raça Santa Inês, não prenhas, não lactantes e canuladas no rúmen. O delineamento experimental utilizado foi o quadrado latino, com quatro tratamentos (T1 - 0; T2 - 25; T3 - 50 e T4 - 75 mg de monensina/ animal/dia). Foram avaliados o consumo de ração, de matéria seca e o pH do fluido do rúmen. A colheita do líquido ruminal para determinação do pH foi realizada às 0; 2; 4; 6 e 8 horas após a alimentação. As análises de variância para consumo de ração e de matéria seca mostraram não haver efeito significativo dos níveis de monensina. Não foi observado efeito significativo nos valores médios do pH ruminal de cada tratamento e na interação tratamento x tempo; os valores de pH ruminal foram considerados normais. Houve diferença estatística no decorrer das horas. O consumo voluntário de alimentos e o pH do líquido ruminal não foram influenciados pela adição da monensina sódica na dieta dos ovinos, para a qual os valores de pH permaneceram elevados, caracterizando um bom ambiente de fermentação ruminal

Muscle mass to visceral fat ratio is an important predictor of the metabolic syndrome in college students

This study aimed to evaluate the associations between the muscle mass to visceral fat (MVF) ratio and cardiometabolic risk factors in a large population of college students in Colombia and to propose cut-off points of this index for the metabolic syndrome (MetS). A total of 1464 young adults recruited from the FUPRECOL (Asociación de la Fuerza Prensil con Manifestaciones Tempranas de Riesgo Cardiovascular en Jóvenes y Adultos Colombianos) study were categorised into four groups based on their MVF ratio. Muscle mass and visceral fat level of the participants were measured using a bioelectrical impedance analysis. Cardiometabolic risk factors including lifestyle characteristics, anthropometry, blood pressure and biochemical parameters were assessed. The prevalence of moderate to severe obesity, hypertension and the MetS was higher in subjects in quartile (Q)1 (lower MVF ratio) (P less than 0·001). ANCOVA revealed that the subjects in Q1 had higher cardiometabolic disturbances, including altered anthropometry, blood pressure, muscle strength and biochemical parameters after adjusting for age and sex compared with young adults in higher MVF ratio quartiles (P less than 0·001). Muscular mass and physical activity levels were significantly lower in subjects with a lower MVF ratio (P less than 0·001). The receiver operating characteristic curve analyses indicated that in men the best MVF ratio cut-off point for detecting the MetS was 18·0 (AUC 0·83, sensitivity 78 % and specificity 77 %) and for women, the MVF ratio cut-off point was 13·7 (AUC 0·85, sensitivity 76 % and specificity 87 %). A lower MVF ratio is associated with a higher risk cardiometabolic profile in early adulthood, supporting that the MVF ratio could be used as a complementary screening tool that may help clinicians identify young adults at high cardiometabolic risk. © The Authors 2018

Single-cell transcriptomics analysis of human small antral follicles

Stem cells & developmental biolog

Determinants of human adipose tissue gene expression: impact of diet, sex, metabolic status, and cis genetic regulation

Weight control diets favorably affect parameters of the metabolic syndrome and delay the onset of diabetic complications. The adaptations occurring in adipose tissue (AT) are likely to have a profound impact on the whole body response as AT is a key target of dietary intervention. Identification of environmental and individual factors controlling AT adaptation is therefore essential. Here, expression of 271 transcripts, selected for regulation according to obesity and weight changes, was determined in 515 individuals before, after 8-week low-calorie diet-induced weight loss, and after 26-week ad libitum weight maintenance diets. For 175 genes, opposite regulation was observed during calorie restriction and weight maintenance phases, independently of variations in body weight. Metabolism and immunity genes showed inverse profiles. During the dietary intervention, network-based analyses revealed strong interconnection between expression of genes involved in de novo lipogenesis and components of the metabolic syndrome. Sex had a marked influence on AT expression of 88 transcripts, which persisted during the entire dietary intervention and after control for fat mass. In women, the influence of body mass index on expression of a subset of genes persisted during the dietary intervention. Twenty-two genes revealed a metabolic syndrome signature common to men and women. Genetic control of AT gene expression by cis signals was observed for 46 genes. Dietary intervention, sex, and cis genetic variants independently controlled AT gene expression. These analyses help understanding the relative importance of environmental and individual factors that control the expression of human AT genes and therefore may foster strategies aimed at improving AT function in metabolic diseases

Dilepton mass spectra in p+p collisions at sqrt(s)= 200 GeV and the contribution from open charm

The PHENIX experiement has measured the electron-positron pair mass spectrum from 0 to 8 GeV/c^2 in p+p collisions at sqrt(s)=200 GeV. The contributions from light meson decays to e^+e^- pairs have been determined based on measurements of hadron production cross sections by PHENIX. They account for nearly all e^+e^- pairs in the mass region below 1 GeV/c^2. The e^+e^- pair yield remaining after subtracting these contributions is dominated by semileptonic decays of charmed hadrons correlated through flavor conservation. Using the spectral shape predicted by PYTHIA, we estimate the charm production cross section to be 544 +/- 39(stat) +/- 142(syst) +/- 200(model) \mu b, which is consistent with QCD calculations and measurements of single leptons by PHENIX.Comment: 375 authors from 57 institutions, 18 pages, 4 figures, 2 tables. Submitted to Physics Letters B. v2 fixes technical errors in matching authors to institutions. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Inclusive cross section and double helicity asymmetry for \pi^0 production in p+p collisions at sqrt(s)=200 GeV: Implications for the polarized gluon distribution in the proton

The PHENIX experiment presents results from the RHIC 2005 run with polarized proton collisions at sqrt(s)=200 GeV, for inclusive \pi^0 production at mid-rapidity. Unpolarized cross section results are given for transverse momenta p_T=0.5 to 20 GeV/c, extending the range of published data to both lower and higher p_T. The cross section is described well for p_T < 1 GeV/c by an exponential in p_T, and, for p_T > 2 GeV/c, by perturbative QCD. Double helicity asymmetries A_LL are presented based on a factor of five improvement in uncertainties as compared to previously published results, due to both an improved beam polarization of 50%, and to higher integrated luminosity. These measurements are sensitive to the gluon polarization in the proton, and exclude maximal values for the gluon polarization.Comment: 375 authors, 7 pages, 3 figures. Submitted to Phys. Rev. D, Rapid Communications. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

System Size and Energy Dependence of Jet-Induced Hadron Pair Correlation Shapes in Cu+Cu and Au+Au Collisions at sqrt(s_NN) = 200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from {dijets} in Cu+Cu and Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from \Delta\phi=\pi in central and semi-central collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.Comment: 464 authors from 60 institutions, 6 pages, 3 figures, 2 tables. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurement of Bottom versus Charm as a Function of Transverse Momentum with Electron-Hadron Correlations in p+p Collisions at sqrt(s)=200 GeV

The momentum distribution of electrons from semi-leptonic decays of charm and bottom for mid-rapidity |y|<0.35 in p+p collisions at sqrt(s)=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 2 < p_T < 7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D^bar --> e^{+/-} K^{-/+} X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in p_T. A fixed-order-plus-next-to-leading-log (FONLL) perturbative quantum chromodynamics (pQCD) calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is \sigma_{b\b^bar}= 3.2 ^{+1.2}_{-1.1}(stat) ^{+1.4}_{-1.3}(syst) micro b.Comment: 432 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm