2,127 research outputs found

    Exploring circumstellar effects on the lithium and calcium abundances in massive Galactic O-rich AGB stars

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    Context. We previously explored the circumstellar effects on Rb and Zr abundances in a sample (21) of massive Galactic O-rich asymptotic giant branch (AGB) stars. Here we are interested in clarifying the role of the extended atmosphere in the case of Li and Ca. Li is an important indicator of hot bottom burning while the total Ca abundances in these stars could be affected by neutron captures.Aims. We report new Li and Ca abundances in a larger sample (30) of massive Galactic O-rich AGB stars by using more-realistic extended model atmospheres. Li abundances had previously studied with hydrostatic models, while the Ca abundances have been determined here for the first time.Methods. We used a modified version of the spectral synthesis code Turbospectrum and consider the presence of a gaseous circumstellar envelope and radial wind in the modelling of the spectra of these massive AGB stars. The Li and Ca abundances were obtained from the 6708 angstrom Li I and 6463 angstrom Ca I resonance lines, respectively. In addition, we studied the sensitivity of the pseudo-dynamical models to variations of the stellar and wind parameters.Results. The Li abundances derived with the pseudo-dynamical models are very similar to those obtained from hydrostatic models (the average difference is 0.18 dex, sigma(2) = 0.02), with no difference for Ca. This indicates that the Li and Ca content in these stars is only slightly affected by the presence of a circumstellar envelope. We also found that the Li I and Ca I line profiles are not very sensitive to variations of the model wind parameters.Conclusions. The new Li abundances confirm the Li-rich (and super Li-rich, in some cases) nature of the sample stars, supporting the activation of hot bottom burning in massive Galactic AGB stars. This is in good agreement with the theoretical predictions for solar metallicity AGB models from ATON, Monash, and NuGrid/MESA but is at odds with the FRUITY database, which predicts no hot bottom burning leading to the production of Li. Most (20) sample stars display nearly solar (within the estimated errors and considering possible non-local thermodynamic equilibrium effects) Ca abundances that are consistent with the available s-process nucleosynthesis models for solar metallicity massive AGB stars, which predict overproduction of Ca-46 relatively to the other Ca isotope and the creation of the radioactive isotope Ca-41 (half life of 0.1 Myr) but no change in the total Ca abundance. A minority (five) of the sample stars seem to show a significant Ca depletion (by up to 1.0 dex). Possible explanations are offered to explain their apparent and unexpected Ca depletion

    Mathematical modeling and forecasting of COVID-19: experience in Santiago de Cuba province

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    In the province of Santiago de Cuba, Cuba, the COVID-19 epidemic has a limited progression that shows an early small-number peak of infections. Most published mathematical models fit data with high numbers of confirmed cases. In contrast, small numbers of cases make it difficult to predict the course of the epidemic. We present two known models adapted to capture the noisy dynamics of COVID-19 in the Santiago de Cuba province. Parameters of both models were estimated using the approximate-Bayesian-computation framework with dedicated error laws. One parameter of each model was updated on key dates of travel restrictions. Both models approximately predicted the infection peak and the end of the COVID-19 epidemic in Santiago de Cuba. The first model predicted 57 reported cases and 16 unreported cases. Additionally, it estimated six initially exposed persons. The second model forecasted 51 confirmed cases at the end of the epidemic. In conclusion, an opportune epidemiological investigation, along with the low number of initially exposed individuals, might partly explain the favorable evolution of the COVID-19 epidemic in Santiago de Cuba. With the available data, the simplest model predicted the epidemic evolution with greater precision, and the more complex model helped to explain the epidemic phenomenology

    Pooled Analysis of a Self-Sampling HPV DNA Test as a Cervical Cancer Primary Screening Method

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    BackgroundWorldwide, one-seventh of cervical cancers occur in China, which lacks a national screening program. By evaluating the diagnostic accuracy of self-collected cervicovaginal specimens tested for human papillomavirus (HPV) DNA (Self-HPV testing) in China, we sought to determine whether Self-HPV testing may serve as a primary cervical cancer screening method in low-resource settings.MethodsWe compiled individual patient data from five population-based cervical cancer–screening studies in China. Participants (n = 13 140) received Self-HPV testing, physician-collected cervical specimens for HPV testing (Physician-HPV testing), liquid-based cytology (LBC), and visual inspection with acetic acid (VIA). Screen-positive women underwent colposcopy and confirmatory biopsy. We analyzed the accuracies of pooled Self-HPV testing, Physician-HPV testing, VIA, and LBC to detect biopsy-confirmed cervical intraepithelial neoplasia grade 2 or more severe (CIN2+) and CIN3+. All statistical tests were two-sided.ResultsOf 13 004 women included in the analysis, 507 (3.9%) were diagnosed as CIN2+, 273 (2.1%) as CIN3+, and 37 (0.3%) with cervical cancer. Self-HPV testing had 86.2% sensitivity and 80.7% specificity for detecting CIN2+ and 86.1% sensitivity and 79.5% specificity for detecting CIN3+. VIA had statistically significantly lower sensitivity for detecting CIN2+ (50.3%) and CIN3+ (55.7%) and higher specificity for detecting CIN2+ (87.4%) and CIN3+ (86.9%) (all P values < .001) than Self-HPV testing, LBC had lower sensitivity for detecting CIN2+ (80.7%, P = .015), similar sensitivity for detecting CIN3+ (89.0%, P = .341), and higher specificity for detecting CIN2+ (94.0%, P < .001) and CIN3+ (92.8%, P < .001) than Self-HPV testing. Physician-HPV testing was more sensitive for detecting CIN2+ (97.0%) and CIN3+ (97.8%) but similarly specific for detecting CIN2+ (82.7%) and CIN3+ (81.3%) (all P values <.001) than Self-HPV testing.ConclusionsThe sensitivity of Self-HPV testing compared favorably with that of LBC and was superior to the sensitivity of VIA. Self-HPV testing may complement current screening programs by increasing population coverage in settings that do not have easy access to comprehensive cytology-based screening

    The Correlation between Mixing Length and Metallicity on the Giant Branch: Implications for Ages in the Gaia Era

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    In the updated APOGEE-Kepler catalog, we have asteroseismic and spectroscopic data for over 3000 first ascent red giants. Given the size and accuracy of this sample, these data offer an unprecedented test of the accuracy of stellar models on the post-main-sequence. When we compare these data to theoretical predictions, we find a metallicity dependent temperature offset with a slope of around 100 K per dex in metallicity. We find that this effect is present in all model grids tested, and that theoretical uncertainties in the models, correlated spectroscopic errors, and shifts in the asteroseismic mass scale are insufficient to explain this effect. Stellar models can be brought into agreement with the data if a metallicity-dependent convective mixing length is used, with Delta alpha(ML), YREC similar to 0.2 per dex in metallicity, a trend inconsistent with the predictions of three-dimensional stellar convection simulations. If this effect is not taken into account, isochrone ages for red giants from the Gaia data will be off by as much as a factor of two even at modest deviations from solar metallicity ([Fe/H]- -0.5)

    FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

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    Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK

    El asiento de avería y el origen de la compañía privilegiada en España

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    El presente artículo analiza cómo la autonomía patrimonial del capital destinado a la organización de las flotas con América acabó adquiriendo la forma de una verdadera compañía privilegiada de comercio, antecedente directo de la actual sociedad anónima, cuando la Corona dejó por entero a los particulares la administración de la avería a través del sistema de asientos. Los paralelismos de los asientos con las compañías llegaron a ser tan grandes que los funcionarios a quienes el conde-duque de Olivares encomendó el estudio de las compañías extranjeras, con objeto de introducirlas en España, vieron en los asientos una verdadera compañía privilegiada.This paper analyses how the progressive autonomy of the capital used to arrange the treasure fleets from Seville to America derived in a real chartered company, a precedent of today’s joint-stock company, when the Crown finally privatised it through the asientos de avería. The parallelism among the asientos and the companies were so noticeable that the public officers appointed by the Count-Duke of Olivares to study the foreign companies couldn’t detect any difference between both institutions.Publicad

    Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

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    Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure

    Measurement of Jet Shapes in Photoproduction at HERA

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    The shape of jets produced in quasi-real photon-proton collisions at centre-of-mass energies in the range 134277134-277 GeV has been measured using the hadronic energy flow. The measurement was done with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the ηϕ\eta - \phi plane with a cone radius of one unit. Measured jet shapes both in inclusive jet and dijet production with transverse energies ETjet>14E^{jet}_T>14 GeV are presented. The jet shape broadens as the jet pseudorapidity (ηjet\eta^{jet}) increases and narrows as ETjetE^{jet}_T increases. In dijet photoproduction, the jet shapes have been measured separately for samples dominated by resolved and by direct processes. Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct processes describe well the measured jet shapes except for the inclusive production of jets with high ηjet\eta^{jet} and low ETjetE^{jet}_T. The observed broadening of the jet shape as ηjet\eta^{jet} increases is consistent with the predicted increase in the fraction of final state gluon jets.Comment: 29 pages including 9 figure

    SARS-CoV-2 positivity in offspring and timing of mother-to-child transmission: living systematic review and meta-analysis

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    OBJECTIVES: To assess the rates of SARS-CoV-2 positivity in babies born to mothers with SARS-CoV-2 infection, the timing of mother-to-child transmission and perinatal outcomes, and factors associated with SARS-CoV-2 status in offspring. DESIGN: Living systematic review and meta-analysis. DATA SOURCES: Major databases between 1 December 2019 and 3 August 2021. STUDY SELECTION: Cohort studies of pregnant and recently pregnant women (including after abortion or miscarriage) who sought hospital care for any reason and had a diagnosis of SARS-CoV-2 infection, and also provided data on offspring SARS-CoV-2 status and risk factors for positivity. Case series and case reports were also included to assess the timing and likelihood of mother-to-child transmission in SARS-CoV-2 positive babies. DATA EXTRACTION: Two reviewers independently extracted data and assessed study quality. A random effects model was used to synthesise data for rates, with associations reported using odds ratios and 95% confidence intervals. Narrative syntheses were performed when meta-analysis was inappropriate. The World Health Organization classification was used to categorise the timing of mother-to-child transmission (in utero, intrapartum, early postnatal). RESULTS: 472 studies (206 cohort studies, 266 case series and case reports; 28 952 mothers, 18 237 babies) were included. Overall, 1.8% (95% confidence interval 1.2% to 2.5%; 140 studies) of the 14 271 babies born to mothers with SARS-CoV-2 infection tested positive for the virus with reverse transcriptase polymerase chain reaction (RT-PCR). Of the 592 SARS-CoV-2 positive babies with data on the timing of exposure and type and timing of tests, 14 had confirmed mother-to-child transmission: seven in utero (448 assessed), two intrapartum (18 assessed), and five during the early postnatal period (70 assessed). Of the 800 SARS-CoV-2 positive babies with outcome data, 20 were stillbirths, 23 were neonatal deaths, and eight were early pregnancy losses; 749 babies were alive at the end of follow-up. Severe maternal covid-19 (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), maternal death (14.1, 4.1 to 48.0), maternal admission to an intensive care unit (3.5, 1.7 to 6.9), and maternal postnatal infection (5.0, 1.2 to 20.1) were associated with SARS-CoV-2 positivity in offspring. Positivity rates using RT-PCR varied between regions, ranging from 0.1% (95% confidence interval 0.0% to 0.3%) in studies from North America to 5.7% (3.2% to 8.7%) in studies from Latin America and the Caribbean. CONCLUSION: SARS-CoV-2 positivity rates were found to be low in babies born to mothers with SARS-CoV-2 infection. Evidence suggests confirmed vertical transmission of SARS-CoV-2, although this is likely to be rare. Severity of maternal covid-19 appears to be associated with SARS-CoV-2 positivity in offspring. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020178076. READERS' NOTE: This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication
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