2,414 research outputs found
Alpha element abundances and gradients in the Milky Way bulge from FLAMES-GIRAFFE spectra of 650 K giants
We obtained FLAMES-GIRAFFE spectra (R=22,500) at the ESO Very Large Telescope
for 650 bulge red giant branch (RGB) stars and performed spectral synthesis to
measure Mg, Ca, Ti, and Si abundances. This sample is composed of 474 giant
stars observed in 3 fields along the minor axis of the Galactic bulge and at
latitudes b=-4, b=-6, b=-12. Another 176 stars belong to a field containing the
globular cluster NGC 6553, located at b=-3 and 5 degrees away from the other
three fields along the major axis. Our results confirm, with large number
statistics, the chemical similarity between the Galactic bulge and thick disk,
which are both enhanced in alpha elements when compared to the thin disk. In
the same context, we analyze [alpha/Fe] vs. [Fe/H] trends across different
bulge regions. The most metal rich stars, showing low [alpha/Fe] ratios at b=-4
disappear at higher Galactic latitudes in agreement with the observed
metallicity gradient in the bulge. Metal-poor stars ([Fe/H]<-0.2) show a
remarkable homogeneity at different bulge locations. We have obtained further
constrains for the formation scenario of the Galactic bulge. A metal-poor
component chemically indistinguishable from the thick disk hints for a fast and
early formation for both the bulge and the thick disk. Such a component shows
no variation, neither in abundances nor kinematics, among different bulge
regions. A metal-rich component showing low [alpha/Fe] similar to those of the
thin disk disappears at larger latitudes. This allows us to trace a component
formed through fast early mergers (classical bulge) and a disk/bar component
formed on a more extended timescale.Comment: 13 pages, 17 figures. Accepted for publication in Astronomy and
Astrophysic
Depuranat project: sustainable management of wastewater in rural areas
The Urban Wastewater Directive is aiming to implement adequate treatments of collected
wastewater before 31 December 2005 in small communities with a population until 2000 equivalentinhabitant.
Within the framework of the DEPURANAT project, co-financed by the European
Interregional Cooperation Programme (Interreg IIIB Atlantic Arc), several Natural Reclamation
Systems (NRS) based upon no-conventional technologies of wastewater treatment, have been
studied from different points of view in rural areas: their effectiveness for producing regenerated
wastewater of acceptable quality for several reuse options and vegetal biomass for different
purposes, their environmental integration or their potential of implementation. Most of these
treatment plants achieved high mean removal efficiencies: TSS (73â96%); BOD5 (74â94%); COD
(53â90%); E. coli (2â3 log units); Enterococci (1.5â4 log units). The environmental impact of the
systems was determined using an adapted life cycle assessment methodology and the economic
analysis of the systems was focused on analysing the financial indicators, empirical cost functions,
and the potential market for these technologies. Furthermore, maps of potential implementation
of these systems and a support tool for deciding upon the installation of conventional or NRS
were designed with the aim of promoting them.Communitary Interreg III-B Atlantic Area of EuropeDEPURANAT consortiu
Karyotypic description of the stingless bee Oxytrigona cf. flaveola (Hymenoptera, Apidae, Meliponina) of a colony from TangarĂĄ da Serra, Mato Grosso State, Brazil
The aim was to broaden knowledge on the cytogenetics of the subtribe Meliponina, by furnishing cytogenetic data as a contribution to the characterization of bees from the genus Oxytrigona. Individuals of the species Oxytrigona cf. flaveola, members of a colony from TangarĂĄ da Serra, Mato Grosso State, Brazil, were studied. The chromosome number was 2n = 34, distributed among four chromosomal morphologies, with the karyotype formula 8m+8sm+16st+2t. Size heteromorphism in the first metacentric pair, subsequently confirmed by sequential staining with fluorochrome (DA/DAPI/CMA3 ), was apparent in all the examined individuals The nucleolar organizing regions (NORs) are possibly located in this metacentric chromosome pair. These data will contribute towards a better understanding of the genus Oxytrigona. Given that species in this group are threatened, the importance of their preservation and conservation can be shown in a sensible, concise fashion through studies such as this
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
Network metaâanalysis of postâexposure prophylaxis randomized clinical trials
Objectives: We performed a network metaâanalysis of PEP randomized clinical trials to evaluate the best regimen. /
Methods: After MEDLINE/Pubmed search, studies were included if: (1) were randomized, (2) comparing at least 2 PEP threeâdrug regimens and, (3) reported completion rates or discontinuation at 28 days. Five studies with 1105 PEP initiations were included and compared ritonavirâboosted lopinavir (LPV/r) vs. atazanavir (ATV) (one study), cobicistatâboosted elvitegravir (EVG/c) (one study), raltegravir (RAL) (one study) or maraviroc (MVC) (two studies). We estimated the probability of each treatment of being the best based on the evaluation of five outcomes: PEP nonâcompletion at day 28, PEP discontinuation due to adverse events, PEP switching due to any cause, lost to followâup and adverse events. /
Results: Participants were mostly men who have sex with men (n = 832, 75%) with nonâoccupational exposure to HIV (89.86%). Fourâhundred fiftyâfour (41%) participants failed to complete their PEP course for any reason. The Odds Ratio (OR) for PEP nonâcompletion at day 28 in each antiretroviral compared to LPV/r was: ATV 0.95 (95% CI 0.58â1.56; EVG/c: OR 0.65 95% CI 0.30â1.37; RAL: OR 0.68 95% CI 0.41â1.13; and MVC: OR 0.69 95% CI 0.47â1.01. In addition, the rankogram showed that EVG/c had the highest probability of being the best treatment for the lowest rates in PEP nonâcompletion at day 28, switching, lost to followâup or adverse events and MVC for PEP discontinuations due to adverse events. /
Conclusions: Our study shows the advantages of integrase inhibitors when used as PEP, particularly EVG as a SingleâTablet Regimen
Methodology to Estimate Natural- and Vaccine-induced antibodies to Sars-Cov-2 in a Large Geographic Region
Accurate estimates of natural and/or vaccine-induced antibodies to SARS-CoV-2 are difficult to obtain. Although model-based estimates of seroprevalence have been proposed, they require inputting unknown parameters including viral reproduction number, longevity of immune response, and other dynamic factors. In contrast to a model-based approach, the current study presents a data-driven detailed statistical procedure for estimating total seroprevalence (defined as antibodies from natural infection or from full vaccination) in a region using prospectively collected serological data and state-level vaccination data. Specifically, we conducted a longitudinal statewide serological survey with 88,605 participants 5 years or older with 3 prospective blood draws beginning September 30, 2020. Along with state vaccination data, as of October 31, 2021, the estimated percentage of those 5 years or older with naturally occurring antibodies to SARS-CoV-2 in Texas is 35.0% (95% CI = (33.1%, 36.9%)). This is 3Ă higher than, state-confirmed COVID-19 cases (11.83%) for all ages. The percentage with naturally occurring or vaccine-induced antibodies (total seroprevalence) is 77.42%. This methodology is integral to pandemic preparedness as accurate estimates of seroprevalence can inform policy-making decisions relevant to SARS-CoV-2
Antibody Duration after infection From Sars-Cov-2 in the Texas Coronavirus antibody Response Survey
Understanding the duration of antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that causes COVID-19 is important to controlling the current pandemic. Participants from the Texas Coronavirus Antibody Response Survey (Texas CARES) with at least 1 nucleocapsid protein antibody test were selected for a longitudinal analysis of antibody duration. A linear mixed model was fit to data from participants (n = 4553) with 1 to 3 antibody tests over 11 months (1 October 2020 to 16 September 2021), and models fit showed that expected antibody response after COVID-19 infection robustly increases for 100 days postinfection, and predicts individuals may remain antibody positive from natural infection beyond 500 days depending on age, body mass index, smoking or vaping use, and disease severity (hospitalized or not; symptomatic or not)
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
The Gaia-ESO Survey::Exploring the complex nature and origins of the Galactic bulge populations
Context. As observational evidence steadily accumulates, the nature of the Galactic bulge has proven to be rather complex: the structural, kinematic, and chemical analyses often lead to contradictory conclusions. The nature of the metal-rich bulge - and especially of the metal-poor bulge - and their relation with other Galactic components, still need to be firmly defined on the basis of statistically significant high-quality data samples. Aims. We used the fourth internal data release of the Gaia-ESO survey to characterize the bulge metallicity distribution function (MDF), magnesium abundance, spatial distribution, and correlation of these properties with kinematics. Moreover, the homogeneous sampling of the different Galactic populations provided by the Gaia-ESO survey allowed us to perform a comparison between the bulge, thin disk, and thick disk sequences in the [Mg/Fe] vs. [Fe/H] plane in order to constrain the extent of their eventual chemical similarities. Methods. We obtained spectroscopic data for âŒ2500 red clump stars in 11 bulge fields, sampling the area -10° â„ l â„ +8° and -10° â„ b â„ -4° from the fourth internal data release of the Gaia-ESO survey. A sample of âŒ6300 disk stars was also selected for comparison. Spectrophotometric distances computed via isochrone fitting allowed us to define a sample of stars likely located in the bulge region. Results. From a Gaussian mixture models (GMM) analysis, the bulge MDF is confirmed to be bimodal across the whole sampled area. The relative ratio between the two modes of the MDF changes as a function of b, with metal-poor stars dominating at high latitudes. The metal-rich stars exhibit bar-like kinematics and display a bimodality in their magnitude distribution, a feature which is tightly associated with the X-shape bulge. They overlap with the metal-rich end of the thin disk sequence in the [Mg/Fe] vs. [Fe/H] plane. On the other hand, metal-poor bulge stars have a more isotropic hot kinematics and do not participate in the X-shape bulge. Their Mg enhancement level and general shape in the [Mg/Fe] vs. [Fe/H] plane is comparable to that of the thick disk sequence. The position at which [Mg/Fe] starts to decrease with [Fe/H], called the "knee", is observed in the metal-poor bulge at [Fe/H]knee = -0:37 ± 0:09, being 0.06 dex higher than that of the thick disk. Although this difference is inside the error bars, it suggest a higher star formation rate (SFR) for the bulge than for the thick disk. We estimate an upper limit for this difference of Î[Fe/H]knee = 0:24 dex. Finally, we present a chemical evolution model that suitably fits the whole bulge sequence by assuming a fast (<1 Gyr) intense burst of stellar formation that takes place at early epochs. Conclusions.We associate metal-rich stars with the bar boxy/peanut bulge formed as the product of secular evolution of the early thin disk. On the other hand, the metal-poor subpopulation might be the product of an early prompt dissipative collapse dominated by massive stars. Nevertheless, our results do not allow us to firmly rule out the possibility that these stars come from the secular evolution of the early thick disk. This is the first time that an analysis of the bulge MDF and α-abundances has been performed in a large area on the basis of a homogeneous, fully spectroscopic analysis of high-resolution, high S/N data
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