34 research outputs found
Evaluation of the effects of erythritol on gene expression in Brucella abortus
Bacteria of the genus Brucella have the unusual capability to catabolize erythritol and this property has been associated with their virulence mainly because of the presence of erythritol in bovine foetal tissues and because the attenuated S19 vaccine strain is the only Brucella strain unable to oxydize erythritol. In this work we have analyzed the transcriptional changes produced in Brucella by erythritol by means of two high throughput approaches: RNA hybridization against a microarray containing most of Brucella ORF's constructed from the Brucella ORFeome and next generation sequencing of Brucella mRNA in an Illumina GAIIx platform. The results obtained showed the overexpression of a group of genes, many of them in a single cluster around the ery operon, able to co-ordinately mediate the transport and degradation of erythritol into three carbon atoms intermediates that will be then converted into fructose-6P (F6P) by gluconeogenesis. Other induced genes participating in the nonoxidative branch of the pentose phosphate shunt and the TCA may collaborate with the ery genes to conform an efficient degradation of sugars by this route. On the other hand, several routes of amino acid and nucleotide biosynthesis are up-regulated whilst amino acid transport and catabolism genes are down-regulated. These results corroborate previous descriptions indicating that in the presence of erythritol, this sugar was used preferentially over other compounds and provides a neat explanation of the the reported stimulation of growth induced by erythritol
Identification of carbon dioxide in an exoplanet atmosphere
Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called âmetallicityâ)1â3, and thus the formation processes of the primary atmospheres of hot gas giants4â6. It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets7â9. Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification10â12. Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme13,14. The data used in this study span 3.0â5.5 micrometres in wavelength and show a prominent CO2 absorption feature at 4.3 micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiativeâconvectiveâthermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models
GWTC-2.1: Deep extended catalog of compact binary coalescences observed by LIGO and Virgo during the first half of the third observing run
The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15 ⶠ00 UTC and 1 October 2019 15 ⶠ00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have a probability of astrophysical origin greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. We also calculate updated source properties for all binary black hole events previously reported in GWTC-1. If the eight additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects â„ 3 Mâ ) is increased compared to GWTC-2, with total masses from ⌠14 M â for GW190924_021846 to ⌠182 Mâ for GW190426_190642. Source properties calculated using our default prior suggest that the primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair-instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than 0.65 and 0.44 at 90% probability for GW190403_051519 and GW190917_114630 respectively), and find that two of the eight new events have effective inspiral spins Ïeff > 0 (at 90% credibility), while no binary is consistent with Ïeff < 0 at the same significance. We provide updated estimates for rates of binary black hole and binary neutron star coalescence in the local Universe
All-sky, all-frequency directional search for persistent gravitational waves from Advanced LIGOâs and Advanced Virgoâs first three observing runs
We present the first results from an all-sky all-frequency (ASAF) search for
an anisotropic stochastic gravitational-wave background using the data from the
first three observing runs of the Advanced LIGO and Advanced Virgo detectors.
Upper limit maps on broadband anisotropies of a persistent stochastic
background were published for all observing runs of the LIGO-Virgo detectors.
However, a broadband analysis is likely to miss narrowband signals as the
signal-to-noise ratio of a narrowband signal can be significantly reduced when
combined with detector output from other frequencies. Data folding and the
computationally efficient analysis pipeline, {\tt PyStoch}, enable us to
perform the radiometer map-making at every frequency bin. We perform the search
at 3072 {\tt{HEALPix}} equal area pixels uniformly tiling the sky and in every
frequency bin of width ~Hz in the range ~Hz, except for bins
that are likely to contain instrumental artefacts and hence are notched. We do
not find any statistically significant evidence for the existence of narrowband
gravitational-wave signals in the analyzed frequency bins. Therefore, we place
confidence upper limits on the gravitational-wave strain for each
pixel-frequency pair, the limits are in the range . In addition, we outline a method to identify candidate
pixel-frequency pairs that could be followed up by a more sensitive (and
potentially computationally expensive) search, e.g., a matched-filtering-based
analysis, to look for fainter nearly monochromatic coherent signals. The ASAF
analysis is inherently independent of models describing any spectral or spatial
distribution of power. We demonstrate that the ASAF results can be
appropriately combined over frequencies and sky directions to successfully
recover the broadband directional and isotropic results
Intervención farmacéutica sobre el uso de antiagregantes plaquetarios en diabéticos tipo 2
OBJETIVOS Medir la prevalencia de pacientes diabéticos tipo 2 que utilizan terapia antiagregante plaquetaria como profilaxis cardiovascular y evaluar el efecto de una intervención farmacéutica sobre su uso.
MĂTODOS Estudio cuasiexperimental en una farmacia comunitaria en Palmera (Valencia), España. El estudio fue realizado desde noviembre de 2007 a enero de 2008.
RESULTADOS Participaron veintinueve de los 58 pacientes diabĂ©ticos tipo 2 seleccionados, quince (51,7%) usaban terapia antiagregante al principio. SĂłlo un paciente (11,1%) no recibĂa antiagregante como prevenciĂłn secundaria, mientras que en prevenciĂłn primaria usaban siete (35%). En cuanto a los que no usaban, diez cumplĂan con los criterios establecidos en las guĂas de prĂĄctica clĂnica para iniciar su uso y fueron intervenidos. Tras dicha intervenciĂłn, tres pacientes comenzaron a usar antiagregante.
CONCLUSIONES En este reducido grupo de diabéticos, el uso de antiagregantes plaquetarios no se encuentra excesivamente extendido, tras la intervención un mayo
Positive Emotions in Children: Current Research and Future Directions
Current studies indicate that positive emotions contribute to the development of social, affective, and cognitive resources that promote psychosocial well-being. However, most research has focused on adolescents and adults rather than children, although the basis for emotional development is established during childhood and affects the emergence of social and cognitive processes during this period. This chapter reviews Latin American studies that have examined how children's positive emotions are related to other variables as well as proposed models for assessing and fostering these emotions. It concludes with suggestions for future research.Fil: Oros, Laura Beatriz. Universidad de la Cuenca del Plata; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentin