M dwarfs in the b201 tile of the VVV survey: Colour-based Selection, Spectral Types and Light Curves

The intrinsically faint M dwarfs are the most numerous stars in the Galaxy, have main-sequence lifetimes longer than the Hubble time, and host some of the most interesting planetary systems known to date. Their identification and classification throughout the Galaxy is crucial to unravel the processes involved in the formation of planets, stars and the Milky Way. The ESO Public Survey VVV is a deep near-IR survey mapping the Galactic bulge and southern plane. The VVV b201 tile, located in the border of the bulge, was specifically selected for the characterisation of M dwarfs. We used VISTA photometry to identify M dwarfs in the VVV b201 tile, to estimate their subtypes, and to search for transit-like light curves from the first 26 epochs of the survey. UKIDSS photometry from SDSS spectroscopically identified M dwarfs was used to calculate their expected colours in the $YJHK_s$ VISTA system. A colour-based spectral subtype calibration was computed. Possible giants were identified by a $(J-K_s, H_{J})$ reduced proper motion diagram. The light curves of 12.8<$K_s$<15.8 colour-selected M dwarfs were inspected for signals consistent with transiting objects. We identified 23,345 objects in VVV b201 with colours consistent with M dwarfs. We provided their spectral types and photometric distances, up to $\sim$ 300 pc for M9s and $\sim$ 1.2 kpc for M4s, from photometry. In the range 12<$K_s$<16, we identified 753 stars as possible giants out of 9,232 M dwarf candidates. While only the first 26 epochs of VVV were available, and 1 epoch was excluded, we were already able to identify transit-like signals in the light curves of 95 M dwarfs and of 12 possible giants. Thanks to its deeper photometry ($\sim$4 magnitudes deeper than 2MASS), the VVV survey will be a major contributor to the discovery and study of M dwarfs and possible companions towards the center of the Milky Way.Comment: 11 pages, 4 figures. Accepted for publication in Catalogs and data of Astronomy and Astrophysic

Gas absorption towards the eta Tel debris disc: winds or clouds?

eta Telescopii is a ~23 Myr old A-type star surrounded by an edge-on debris disc hypothesised to harbour gas. Recent analysis of far- and near-ultraviolet spectroscopic observations of eta Tel found absorption features at ~-23 km/s and ~-18 km/s in several atomic lines, attributed to circumstellar and interstellar gas, respectively. In this work, we put the circumstellar origin of the gas to a test by analysing high resolution optical spectroscopy of eta Tel and of three other stars with a similar line of sight as eta Tel: HD 181327, HD 180575, and rho Tel. We found absorption features at ~-23 km/s and ~-18 km/s in the Ca ii H&K lines, and at ~-23 km/s in the Na i D1&D2 doublet in eta Tel, in agreement with previous findings in the ultraviolet. However, we also found absorption features at ~-23 km/s in the Ca ii K lines of the three other stars analysed. This strongly implies that the absorption lines previously attributed to circumstellar gas are more likely due to an interstellar cloud traversing the line of sight of eta Tel instead.Comment: 6 pages, 3 figures, 3 tables. Accepted for publication in MNRA

Factores de riesgo asociados a hemorragia post- parto, en las mujeres que fueron atendidas en el servicio de Gineco-Obstetricia, del HECAM, Matagalpa en el período 2010-2013

El presente estudio se realizó para poder tomar medidas sobre los principales factores de riesgo asociados a hemorragia postparto por ser una de las principales complicaciones obstétricas a nivel mundial y principal causa de Muerte Materna el 99% se presenta en los países en vías de desarrollo. (Abou & zahr, 2003) La presente investigación Factores asociados a hemorragia post- parto en las mujeres que fueron atendidas en el servicio de Gineco-Obstetricia del HECAM, Matagalpa en el periodo 2010-2013 que tuvo como objetivo describir factores más importantes para la morbimortalidad provocada por esta complicación. El estudio estuvo constituido por 138 mujeres a las que se les atendió parto vía vaginal y cesárea siendo este de tipo descriptivo, retrospectivo, de corte transversal, Con enfoque cuali –cuantitativo, la información se obtuvo de fuente secundaria como el expediente clínico se procesó y analizo en el programa estadístico spss. Encontramos que de 27,998 partos vía vaginal y cesárea atendidos se registró una incidencia La mayoría de las pacientes están en la segunda y tercera década de la vida, son de procedencia rural y no tienen escolaridad. Los factores antes del parto más importantes son: ser Primigesta, tener anemia, ser gran multípara y el SHG; durante el parto los más destacados partos extra hospitalarios, parto precipitado, parto domiciliar, y el trabajo de parto prolongado; al final del parto se presentan en mayor frecuencia: la hipotonía uterina, los desgarros obstétricos, la retención placentaria y de restos placentarios. Tenemos presente que el esfuerzo para disminuir esta complicación tiene que seguir asiéndose a nivel primario con la vigilancia, seguimiento y charlas educativas a las embarazadas: lo que debe ser complementario a nivel secundario con la capacidad de poder manejar los casos con un equipo multidisciplinario y equipamiento adecuad

Optimización del sistema nanoparticulado Fe3-xZnxO4 (0<x<0.5) para su aplicación en hipertermia magnética

[ES] El objetivo general del presente trabajo es la puesta a punto de un método de preparación de nanopartículas magnéticas con propiedades adecuadas para su empleo como agentes generadores de hipertermia en terapias antitumorales. Los materiales escogidos para tal fin son las ferritas de fórmula general ZnxFe3-xO4 debido a que recientes investigaciones indican que la adición del ion Zn+2 en sustitución del ion Fe+2, en un intervalo reducido de concentraciones (x<0.5), da lugar en estas fases a mayores valores de imanación y SAR que los que presenta la magnetita pura. En cuanto al método de preparación se ha optado por la vía de la descomposición térmica de precursores metalorgánicos, que ha demostrado ser más fácil de optimizar para obtener sistemas homogéneos de forma reproducible. Como precursores metalorgánicos se han escogido los oleatos y se prepararán tanto oleatos mixtos con diferentes relaciones Zn:Fe como los oleatos de hierro y zinc de forma separada. En conclusión, se pretende optimizar la síntesis, tanto de los precursores como de las nanopartículas magnéticas, para obtener materiales con tamaño controlado y baja polidispersidad de forma reproducible. Se buscará especialmente la obtención de partículas grandes, con un comportamiento ferromagnético a temperatura ambiente, dado que proporcionan mayores valores de SAR que los materiales superparamagnéticos

Síndrome de burnout, apoyo social en el trabajo y apoyo familiar en personas que realizan voluntariado

El presente estudio relaciona el síndrome de burnout, apoyo social en el trabajo y apoyo familiar en 160 hombres y mujeres que realizan voluntariado en el Perú, entre los 18 a 50 años. Se utilizaron el Cuestionario de Subtipos Clínicos de Burnout (BCSQ 12), la Escala de Apoyo Social en el Trabajo (EAST) y la Escala de Apoyo Familiar (EAF). Los resultados indicaron que la sobrecarga (r = -.311), falta de desarrollo (r = -.420) y abandono (r = -.300) presentan correlaciones negativas con el apoyo social en el trabajo. Se puede observar también que, la Calidad de las Relaciones Familiares y el Cooperación recíproca familiar presenta correlaciones positivas con la sobrecarga (r = .256); (r = .210), falta de desarrollo (r =.273); (r = .233) y abandono (r = .226); (r = .224). Además, la Calidad de las Relaciones Familiares (r = -,203) y la Cooperación recíproca familiar (r = -.280) presentan correlaciones negativas con el apoyo social en el trabajo. Por otro lado, se evidenció que no existen diferencias estadísticamente significativas entre el síndrome de burnout, apoyo social en el trabajo y apoyo familiar según el sexo y grado académico. En consecuencia, el apoyo social en el trabajo y apoyo familiar logra prevenir y sobrellevar respectivamente el impacto del síndrome de burnout en la salud de la persona.The present study relates burnout syndrome, social support at work and family support in 160 men and women volunteers in Peru, aged 18 to 50 years. The Burnout Clinical Subtypes Questionnaire (BCSQ 12), the Social Support at Work Scale (EAST) and the Family Support Scale (EAF) were used. The results indicated that Overload (r = -.311), Lack of Development (r = -.420) and Burnout (r = -.300) have negative correlations with Social Support at Work. It can also be observed that, the Quality of Family Relationships and Family Reciprocal Cooperation present positive correlations with overload (r = .256); (r = .210), lack of development (r = .273); (r = .233) and abandonment (r = .226); (r = .224). In addition, the Quality of Family Relationships (r = -.203) and Family Reciprocal Cooperation (r = -.280) presented negative correlations with social support at work. On the other hand, it was found that there are no statistically significant differences between burnout syndrome, social support at work and family support according to sex and academic grade. Consequently, social support at work and family support are able to prevent and cope respectively with the impact of burnout syndrome on the health of the person.Tesi

Response of the cytoplasmic and membrane proteome of Corynebacterium glutamicum ATCC 13032 to pH changes

<p>Abstract</p> <p>Background</p> <p><it>C. glutamicum </it>has traditionally been grown in neutral-pH media for amino acid production, but in a previous article we reported that this microorganism is a moderate alkaliphile since it grows optimally at pH 7.0–9.0, as shown in fermentor studies under tightly controlled pH conditions. We determined the best pH values to study differential expression of several genes after acidic or basic pH conditions (pH 6.0 for acidic expression and pH 9.0 for alkaline expression). Thus, it was interesting to perform a detailed analysis of the pH-adaptation response of the proteome of <it>C. glutamicum </it>ATCC 13032 to clarify the circuits involved in stress responses in this bacterium. In this paper we used the above indicated pH conditions, based on transcriptional studies, to confirm that pH adaptation results in significant changes in cytoplasmatic and membrane proteins.</p> <p>Results</p> <p>The cytoplasmatic and membrane proteome of <it>Corynebacterium glutamicum </it>ATCC 13032 at different pH conditions (6.0, 7.0 and 9.0) was analyzed by classical 2D-electrophoresis, and by anion exchange chromatography followed by SDS-PAGE (AIEC/SDS-PAGE). A few cytoplasmatic proteins showed differential expression at the three pH values with the classical 2D-technique including a hypothetical protein <it>cg</it>2797, L-2.3-butanediol dehydrogenase (ButA), and catalase (KatA). The AIEC/SDS-PAGE technique revealed several membrane proteins that respond to pH changes, including the succinate dehydrogenase complex (SdhABCD), F₀F₁-ATP synthase complex subunits b, α and δ (AtpF, AtpH and AtpA), the nitrate reductase II α subunit (NarG), and a hypothetical secreted/membrane protein <it>cg</it>0752. Induction of the F₀F₁-ATP synthase complex β subunit (AtpD) at pH 9.0 was evidenced by Western analysis. By contrast, L-2.3-butanediol dehydrogenase (ButA), an ATPase with chaperone activity, the ATP-binding subunit (ClpC) of an ATP-dependent protease complex, a 7 TMHs hypothetical protein <it>cg</it>0896, a conserved hypothetical protein <it>cg</it>1556, and the dihydrolipoamide acyltransferase SucB, were clearly up-regulated at pH 6.0.</p> <p>Conclusion</p> <p>The observed protein changes explain the effect of the extracellular pH on the growth and physiology of <it>C. glutamicum</it>. Some of the proteins up-regulated at alkaline pH respond also to other stress factors suggesting that they serve to integrate the cell response to different stressing conditions.</p

Surprising Complexity of the [Gd(AAZTA)(H2O)2]− Chelate Revealed by NMR in the Frequency and Time Domains

[Abstract] Typically, Ln(III) complexes are isostructural along the series, which enables studying one particular metal chelate to derive the structural features of the others. This is not the case for [Ln(AAZTA)(H2O)x]− (x = 1, 2) systems, where structural variations along the series cause changes in the hydration number of the different metal complexes, and in particular the loss of one of the two metal-coordinated water molecules between Ho and Er. Herein, we present a 1H field-cycling relaxometry and 17O NMR study that enables accessing the different exchange dynamics processes involving the two water molecules bound to the metal center in the [Gd(AAZTA)(H2O)2]− complex. The resulting picture shows one Gd-bound water molecule with an exchange rate ∼6 times faster than that of the other, due to a longer metal–water distance, in accordance with density functional theory (DFT) calculations. The substitution of the more labile water molecule with a fluoride anion in a diamagnetic-isostructural analogue of the Gd-complex, [Y(AAZTA)(H2O)2]−, allows us to follow the chemical exchange process by high-resolution NMR and to describe its thermodynamic behavior. Taken together, the variety of tools offered by NMR (including high-resolution 1H, 19F NMR as a function of temperature, 1H longitudinal relaxation rates vs B0, and 17O transverse relaxation rates vs T) provides a complete description of the structure and exchange dynamics of these Ln-complexes along the series.This research was supported by the Università del Piemonte Orientale (Ricerca locale FAR2019). F.C., L.T., and M.B. acknowledge the financial support from the Ministero dell’Università e della Ricerca (PRIN 2017A2KEPL project “Rationally designed nanogels embedding paramagnetic ions as MRI probes”). This work was carried out within the framework of the COST CA15209 Action “European Network on NMR Relaxometry”Italia. Ministero dell'Università e della Ricerca; PRIN-2017A2KEP