IAA : Información y actualidad astronómica (26)

Sumario : Estrellas de neutrones: furioso magnetismo.-- La astronomía en el arte.-- DECONSTRUCCIÓN Y otros ENSAYOS : Lo más frío del Universo.-- CIENCIA: PILARES E INCERTIDUMBRES : Los meteoritos “ordinarios”.-- ACTUALIDAD.-- ENTRE BASTIDORES : Las generaciones perdidas.-- HISTORIAS DE ASTRONOMÍA : El organista que descubrió Urano.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

IAA : Información y actualidad astronómica (24)

Sumario : Máseres en el espacio.-- Venus Express.-- El complejo cinturón de asteroides.-- DECONSTRUCCIÓN Y otros ENSAYOS : Rotación diferencial y oscilaciones estelares.-- ACTUALIDAD.-- ENTRE BASTIDORES .-- HISTORIAS DE ASTRONOMÍA: El astrónomo de vista prodigiosa.-- CIENCIA: PILARES E INCERTIDUMBRES : Ondas gravitatorias.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

Gut microbiota disturbance during antibiotic therapy: A multi-omic approach

It is known that the gastrointestinal tract (GIT) microbiota responds to different antibiotics in different ways and that while some antibiotics do not induce disturbances of the community, others drastically influence the richness, diversity, and prevalence of bacterial taxa. However, the metabolic consequences thereof, independent of the degree of the community shifts, are not clearly understood. In a recent article, we used an integrative OMICS approach to provide new insights into the metabolic shifts caused by antibiotic disturbance. The study presented here further suggests that specific bacterial lineage blooms occurring at defined stages of antibiotic intervention are mostly associated with organisms that possess improved survival and colonization mechanisms, such as those of the Enterococcus, Blautia, Faecalibacterium, and Akkermansia genera. The study also provides an overview of the most variable metabolic functions affected as a consequence of a β-lactam antibiotic intervention. Thus, we observed that anabolic sugar metabolism, the production of acetyl donors and the synthesis and degradation of intestinal/colonic epithelium components were among the most variable functions during the intervention. We are aware that these results have been established with a single patient and will require further confirmation with a larger group of individuals and with other antibiotics. Future directions for exploration of the effects of antibiotic interventions are discussed.The whole consortium was funded by the Spanish Ministry of Economy and Competitiveness and the Federal Ministry of Education and Research (BMBF) within the ERA NET PathoGenoMics2 program, grant number 0315441A. This work was further funded by grants BFU2008-04501-E, SAF2009-13032-C02–01, SAF2012-31187, and CSD2007-00005 from the Spanish Ministry of Economy and Competitiveness, Prometeo/2009/092 from Generalitat Valenciana (Spain), and AGL2006-11697/ALI. The authors gratefully acknowledge the financial support provided by the European Regional Development Fund (ERDF) and the European Union (FP7 project Systems medicine of chronic inflammatory bowel disease, Grant Agreement no. 305564). This work has been partially supported by the EVASYON study funded by the Spanish Ministry of Health and Consumption (Carlos III Institute of Health. FIS Grant PI 051579).Peer Reviewe

Impact of gaps in the asteroseismic characterization of pulsating stars: I. the efficiency of pre-whitening

Context. It is known that the observed distribution of frequencies in CoRoT and Kepler δ Scuti stars has no parallelism with any theoretical model. Pre-whitening is a widespread technique in the analysis of time series with gaps from pulsating stars located in the classical instability strip, such as δ Scuti stars. However, some studies have pointed out that this technique might introduce biases in the results of the frequency analysis. Aims. This work aims at studying the biases that can result from pre-whitening in asteroseismology. The results will depend on the intrinsic range and distribution of frequencies of the stars. The periodic nature of the gaps in CoRoT observations, only in the range of the pulsational frequency content of the δ Scuti stars, is shown to be crucial to determining their oscillation frequencies, the first step in performing asteroseismology of these objects. Hence, here we focus on the impact of pre-whitening on the asteroseismic characterization of δ Scuti stars. Methods. We select a sample of 15 δ Scuti stars observed by the CoRoT satellite, for which ultra-high-quality photometric data have been obtained by its seismic channel. In order to study the impact on the asteroseismic characterization of δ Scuti stars we perform the pre-whitening procedure on three datasets: gapped data, linearly interpolated data, and data with gaps interpolated using Autoregressive and Moving Average models (ARMA). Results. The different results obtained show that at least in some cases pre-whitening is not an efficient procedure for the deconvolution of the spectral window. Therefore, in order to reduce the effect of the spectral window to a minimum, in addition to performing a pre-whitening of the data, it is necessary to interpolate with an algorithm that is aimed to preserve the original frequency content.© ESO 2018.JPG acknowledge support from the “Junta de Andalucía” local government under project 2012-P12-TIC-2469. JCS and AGH acknowledge funding support from Spanish public funds for research under project ESP2015-65712-C5-5-R (MINECO/FEDER), and from project RYC-2012-09913 under the “Ramón y Cajal” programme of the Spanish MINECO. JCS also acknowledge support by the European FP7 project “SPACEINN” (FP7-SPACE-2011-1). AM acknowledges support by the Spanish MINECO National Space Program through project ESP2015-65712-C5-1-R and “Ramon y Cajal” program RYC-2012-09913. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 749962.Peer Reviewe

Clostridium difficile heterogeneously impacts intestinal community architecture but drives stable metabolome responses

Clostridium difficile-associated diarrhoea (CDAD) is caused by C. difficile toxins A and B and represents a serious emerging health problem. Yet, its progression and functional consequences are unclear. We hypothesised that C. difficile can drive major measurable metabolic changes in the gut microbiota and that a relationship with the production or absence of toxins may be established. We tested this hypothesis by performing metabolic profiling on the gut microbiota of patients with C. difficile that produced (n=6) or did not produce (n=4) toxins and on non-colonised control patients (n=6), all of whom were experiencing diarrhoea. We report a statistically significant separation (P-value o0.05) among the three groups, regardless of patient characteristics, duration of the disease, antibiotic therapy and medical history. This classification is associated with differences in the production of distinct molecules with presumptive global importance in the gut environment, disease progression and inflammation. Moreover, although severe impaired metabolite production and biological deficits were associated with the carriage of C. difficile that did not produce toxins, only previously unrecognised selective features, namely, choline-and acetylputrescine-deficient gut environments, characterised the carriage of toxin-producing C. difficile. Additional results showed that the changes induced by C. difficile become marked at the highest level of the functional hierarchy, namely the metabolic activity exemplified by the gut microbial metabolome regardless of heterogeneities that commonly appear below the functional level (gut bacterial composition). We discuss possible explanations for this effect and suggest that the changes imposed by CDAD are much more defined and predictable than previously thought.The present investigation was funded by the Spanish Ministry of Economy and Competitiveness and the Federal Ministry of Education and Research (BMBF) within the ERA NET PathoGenoMics2 program, grant number 0315441A. This work was further funded by grants BFU2008-04501-E, SAF2009-13032-C02-01, SAF2012- 31187, CSD2007-00005 and BIO2011-25012 from the Spanish Ministry of Economy and Competitiveness, PrometeoII/2'14/065 from Generalitat Valenciana (Spain) and AGL2006-11697/ALI. We gratefully acknowledge the financial support provided by the European Regional Development Fund (ERDF).Peer Reviewe