Search and first detection of very-high-energy photons in gamma-ray bursts: an analysis with HAWC and H.E.S.S.

This thesis is devoted to the study of extremely energetic short-timescale astrophysical events, Gamma-ray bursts (GRBs). GRBs exhibit broad-band bright non-thermal emission, which was analysed using two major experiments: the High Altitude Water Cherenkov observatory (HAWC) and the High Energy Stereoscopic System (H.E.S.S.). The two experiments are in many respects complementary for the observation of very high energy (VHE) gamma-ray emission from GRBs, and in this work the respective advantages were exploited to maximise the sensitivity to VHE signals. After the analysis of several tens of GRBs observed using H.E.S.S. until 2017, where no significant emission was detected, improvements in the observation strategy of H.E.S.S. allowed the detection of GRB 180729B and GRB 190829A. These detections are presented in context with multi-wavelength data, proposing plausible emission mechanisms, thus concluding a decade-long search for these elusive phenomena at VHE. In the second part, novel methods to improve the accuracy of the HAWC detector simulation are presented, including better modelling of the detector efficiencies and electronics. A model that accounts for the detector response and the GRB flux evolution has been developed to estimate the optimal integration time for VHE searches with HAWC. Thanks to these improvements, it is possible to exploit the wide field of view and high duty cycle of HAWC for the search of VHE emission in several tens of GRBs. Preliminary evidence for emission is found in one of the GRBs studied, and upper limits are obtained for all the GRBs analysed and placed in context of the X-ray properties of these events. Finally, the limits and detections presented in this work are placed within the framework of the current understanding of GRBs and prospects for future and present VHE gamma-ray detectors are presented

Multi-messenger astronomy with very-high-energy gamma-ray observations

After decades of development, multi-messenger astronomy, the combination of information on cosmic sources from photons, neutrinos, charged particles and gravitational waves, is now an established reality. Within this emerging discipline we argue that very-high-energy (VHE) gamma-ray observations play a special role. We discuss the recent progress on explosive transients, the connections between neutrino and gamma-ray astronomy and the search for search for dark matter. Finally, the experimental prospects for the next decade in the VHE gamma-ray field are summarised

Structure and shaping processes within the extended atmospheres of AGB stars

We present recent studies using the near-infrared instrument AMBER of the VLT Interferometer (VLTI) to investigate the structure and shaping processes within the extended atmosphere of AGB stars. Spectrally resolved near-infrared AMBER observations of the Mira variable S Ori have revealed wavelength-dependent apparent angular sizes. These data were successfully compared to dynamic model atmospheres, which predict wavelength-dependent radii because of geometrically extended molecular layers. Most recently, AMBER closure phase measurements of several AGB stars have also revealed wavelength-dependent deviations from 0/180 deg., indicating deviations from point symmetry. The variation of closure phase with wavelength indicates a complex non-spherical stratification of the extended atmosphere, and may reveal whether observed asymmetries are located near the photosphere or in the outer molecular layers. Concurrent observations of SiO masers located within the extended molecular layers provide us with additional information on the morphology, conditions, and kinematics of this shell. These observations promise to provide us with new important insights into the shaping processes at work during the AGB phase. With improved imaging capabilities at the VLTI, we expect to extend the successful story of imaging studies of planetary nebulae to the photosphere and extended outer atmosphere of AGB stars.Comment: 6 pages, Proc. of "Asymmetric Planetary Nebulae V", A.A. Zijlstra, F. Lykou, I. McDonald, and E. Lagadec (eds.), Jodrell Bank Centre for Astrophysics, Manchester, UK, 201

Prescripción inducida en atención primaria de la Comarca Bilbao

ObjetivosPrincipales: conocer la proporción de prescripción inducida (PI) en Comarca Bilbao y su procedencia, la proporción de gasto correspondiente a la PI, la proporción de PI en los principales grupos terapéuticos, la actitud del médico de atención primaria ante la prescripción solicitada y su influencia en el gasto, la proporción de desacuerdo con dicha prescripción y los motivos de desacuerdo, y la proporción con informe del especialista. Secundarios: conocer la proporción de PI en los demás grupos terapéuticos, en fármacos VINE, EFG y en los de nula o baja mejora terapéutica.Diseño.Estudio transversal, descriptivoEmplazamientoAtención primariaParticipantesFármacos financiables prescritos por y/o solicitados a los médicos de familia de EAP.Resultados principalesSe estudiaron 7.922 fármacos. Tipo de prescripción: PI, 48,3% (IC del 95%, 47,2–49,4); del médico de atención primaria (PRO), 50,6% (IC del 95%, 49,5–51,7); desconocida, 1,1% (IC del 95%, 0,9–1,3). Procedencia principal: especialista público (72,2%), especialista privado (16,6%). Un 62,5% del gasto correspondió a la PI. En el grupo terapéutico más prescrito, sistema nervioso central (24,2%), PI, 39,8%; PRO, 58,9%; en aparato cardiovascular (19,1%), PI, 56,2%, PRO, 43,1%. Se prescribió el fármaco solicitado en un 98,4% de los casos, se cambio en el 1,2% y se suprimió en un 0,4%. Proporción de desacuerdo, 11%; motivos de desacuerdo, no hay necesidad de tratar (23,9%), grupo terapéutico (34,4%), principio activo (13,2%), marca comercial (28,5%). Hubo informe de especialista en un 62,4% de los casos.ConclusionesSe detecta una proporción considerable de prescripción no atribuible a atención primaria y una proporción importante de fármacos que el médico de primaria prescribe sin estar de acuerdo. Sería necesario un sistema que permitiera separar el gasto por niveles, así como mejorar la comunicación entre éstos.ObjectivesMain objetives: to know the proportion of induced prescription (IP) in Area Bilbao and its source, the proportion of cost IP accounts for, the proportion of IP in the main therapeutic groups, the attitude of GP when requested for prescription and its influence on cost, the proportion of disagreement with requested prescription, the reasons for disagreement, and the proportion with letter from specialist. Secondary objectives: to know the proportion of IP in the remaining therapeutic groups, in drugs of low clinical value, in generic drugs and in new drugs with low or no therapeutic improvement.DesignA descriptive cross-sectional study.SettingPrimary health care.ParticipantsDrugs prescribable under National Health Service prescribed by and/or requested to GPs.Main results7.922 drugs were analysed. Type of prescription: IP, 48.3% (95% CI, 47.2–49.4); GP prescription (GPP), 50.6% (95% CI, 49.5–51.7); unknown source, 1,1% (95% CI, 0.9–1.3). Main source, public specialist (72.2%), private specialist (16.6%). IP accounted for 62.5% of cost. In the most prescribed therapeutic group, central nervous system (24.2%), IP, 39.8%; GPP, 58.9%; in cardiovascular system (19.1%), IP, 56.2%; GPP, 43.1%. 98.4% of requested prescription was actually prescribed, 1.2% was changed and 0.4%, suppressed. Proportion of disagreement, 11%; reasons for disagreement, no need for medical treatment (23.9%), therapeutic group (34.4%), active ingredient (13.2%), brand name (28.5%). There was a 62.4% with letter from specialist.ConclusionsPrimary care is not accountable for a substantial proportion of prescription. GP prescribes a considerable proportion of drugs without agreement. It would be necessary a system that allows to separate the cost by care levels and also improve their communication

Inter-calibration trials between the R/V Cornide de Saavedra and the R/V Miguel Oliver in bottom trawl surveys off the Spanish coast

Bottom trawl surveys are conducted by the Spanish Oceanographic Institute (IEO) to provide information independent from the fisheries of commercial stocks: DEMERSALES in the northern Spanish Shelf, ARSA in the Gulf of Cadiz and MEDITS in the Mediterranean Shelf since 1983, 1993 and 1994, respectively. Surveys have been performed annually on board the R/V Cornide de Saavedra until 2013. This vessel (67 m, 1133 GRT) was built in 1972 and nowadays has been replaced by the new R/V Miguel Oliver (70 m, 2495 GRT). To guarantee the continuity between the two vessels of the abundance and biomass indices of the main target species and their length distributions, inter-calibration experiments have been performed for each of the three bottom trawl surveys. The goal of the inter-calibration between both vessels was to establish the most similar fishing conditions to detect and isolate if there was a vessel effect that caused different results in catches. And in if those differences were significant, to estimate calibration coefficients to homogenize abundance and biomass indices of the new vessel R/V Miguel Oliver with respect to the time series built with the old R/V Cornide de Saavedra. The inter-calibration experiment consisted in performing parallel tows with both vessels, using the same gear, and carrying out hauls of the same duration and speed. The parallel surveys in the V/R Cornide de Saavedra and the R/V Miguel Oliver followed the surveys protocols of IBTS for the northern Spain and Gulf of Cadiz and MEDITS for the Mediterranean. A total of 60 paired hauls were completed in the DEMERSALES survey, 43 for the ARSA and 37 hauls in the MEDITS. Comparisons between both vessels were done in each survey addressing: gear performance, total catch, commercial species catches, length distributions of the most representative species and analyzing the faunal fish assemblages detected. Differences between vessels were less significant for the DEMERSALES survey, with the higher catches, number of hauls and less variability; in the Gulf of Cadiz, catches of flatfish and some species of cephalopods were slightly higher in the R/V Miguel Oliver but no significant differences in the length distributions were found; for the MEDITS survey, catches by haul were lower, presenting a great diversity of species, thus complicating to separate the sources of variability due to the change of vessel from the uncertainty associated to the hauls. In general, catches in the R/V Miguel Oliver are similar to catches in the R/V Cornide de Saavedra. To verify the continuity and congruence of the time series special attention must be paid to the new surveys in the R/V Miguel Oliver to test if inter-calibration factors are needed for some species

Personality traits, theory of mind and their relationship with multiple suicide attempts in a sample of first episode psychosis patients: One-year follow-up study

BACKGROUND: High rates of suicidal behaviour (SB) have been found in first episode psychosis (FEP) patients. It has been suggested that the presence of multiple suicide attempts (mSA) increases the risk of later SA and the risk of eventual death by suicide. OBJECTIVE: Our main objective was to study the baseline factors associated with the presence of mSA during the first year after FEP. In addition, a second aim was to find out whether there were any differences between single and multiple suicide attempters in the timing of the first SA after FEP. METHOD: A total of 65 FEP patients were evaluated. The presence of SAs were recorded at two different times after FEP. Bivariate and multivariate analyses were performed to explore the relationship between SA with sociodemographic and clinical variables. RESULTS: Multiple linear regression showed that mSA was associated with the presence of increased symptom severity (B?=?0.35; t?=?3.67; p < 0.01) and errors in first-order false-belief task (B?=?0.48; t?=?2.11; p?=?0.04). There were significant differences in the timing of first SA after FEP between multiple and single suicide attempters. CONCLUSIONS: Theory of mind impairments along with more severe symptoms during the first contact with mental health services for psychotic symptoms appeared to be important predictors of mSA. On the other hand, multiple suicide attempters tend to make a first SA after FEP earlier than single suicide attempters. These results could contribute to the implementation of preventive suicidal programs, however they must be confirmed by additional research.Funding: This study was funded by Ministry of Science and Innovation grant ISC PI11/0233

Mild and short-term caloric restriction prevents obesity-induced cardiomyopathy in young zucker rats without changing in metabolites and fatty acids cardiac profile

Caloric restriction (CR) ameliorates cardiac dysfunction associated with obesity. However, most of the studies have been performed under severe CR (30-65% caloric intake decrease) for several months or even years in aged animals. Here, we investigated whether mild (20% food intake reduction) and short-term (2-weeks) CR prevented the obese cardiomyopathy phenotype and improved the metabolic profile of young (14 weeks of age) genetically obese Zucker fa/fa rats. Heart weight (HW) and HW/tibia length ratio was significantly lower in fa/fa rats after 2 weeks of CR than in counterparts fed ad libitum. Invasive pressure measurements showed that systolic blood pressure, maximal rate of positive left ventricle (LV) pressure, LV systolic pressure and LV end-diastolic pressure were all significantly higher in obese fa/fa rats than in lean counterparts, which were prevented by CR. Magnetic resonance imaging revealed that the increase in LV end-systolic volume, stroke volume and LV wall thickness observed in fa/fa rats was significantly lower in animals on CR diet. Histological analysis also revealed that CR blocked the significant increase in cardiomyocyte diameter in obese fa/fa rats. High resolution magic angle spinning magnetic resonance spectroscopy analysis of the LV revealed a global decrease in metabolites such as taurine, creatine and phosphocreatine, glutamate, glutamine and glutathione, in obese fa/fa rats, whereas lactate concentration was increased. By contrast, fatty acid concentrations in LV tissue were significantly elevated in obese fa/fa rats. CR failed to restore the LV metabolomic profile of obese fa/fa rats. In conclusion, mild and short-term CR prevented an obesity-induced cardiomyopathy phenotype in young obese fa/fa rats independently of the cardiac metabolic profile.This study was supported by grants from Spanish Ministry of Science and Innovation (BFU2011-25303), Spanish Institute of Health Carlos III (CP15/00129), UCM groups (GR-921641), SESCAMET, Fundación Mutua Madrileña, Fundación Eugenio Rodríguez Pascual and Fondos FEDER.Peer Reviewe