Phenomenological implications of sterile neutrinos in the μν\mu\nuSSM and dark matter

We analyze the role of sterile neutrinos in the framework of the $\mu\nu$SSM, where the presence of right-handed neutrinos provides a simultaneous solution to $\mu$- and $\nu$-problems in supersymmetry. We adopt a minimalistic approach, reproducing light neutrino masses and mixing angles at tree level using just two right-handed neutrinos as part of the seesaw mechanism. A third right-handed neutrino does not contribute significantly to the mass of the three active ones, behaving as a sterile neutrino with a mass in the range keV$-$MeV. Furthermore, a sterile neutrino of about $10$ keV can be a good candidate for dark matter with a lifetime larger than the age of the Universe. In particular, the three-body decay to active neutrinos gives the dominant contribution to its lifetime. The one-loop decay to gamma and active neutrino is subdominant, but relevant for observations such as astrophysical X-rays. We find regions of the parameter space of the $\mu\nu$SSM, with different values of the sterile neutrino mass, fulfilling not only these constraints but also collider constraints from the Higgs sector.Comment: Version published in Astroparticle Physics. Discussion improved including one figure. 24 pages, 7 figures, 2 table

Seeing double with K2: Testing re-inflation with two remarkably similar planets around red giant branch stars

Despite more than 20 years since the discovery of the first gas giant planet with an anomalously large radius, the mechanism for planet inflation remains unknown. Here, we report the discovery of EPIC228754001.01, an inflated gas giant planet found with the NASA K2 Mission, and a revised mass for another inflated planet, K2-97b. These planets reside on ~9 day orbits around host stars which recently evolved into red giants. We constrain the irradiation history of these planets using models constrained by asteroseismology and Keck/HIRES spectroscopy and radial velocity measurements. We measure planet radii of 1.31 +\- 0.11 Rjup and and 1.30 +\- 0.07 Rjup, respectively. These radii are typical for planets receiving the current irradiation, but not the former, zero age main sequence irradiation of these planets. This suggests that the current sizes of these planets are directly correlated to their current irradiation. Our precise constraints of the masses and radii of the stars and planets in these systems allow us to constrain the planetary heating efficiency of both systems as 0.03% +0.03%/-0.02%. These results are consistent with a planet re-inflation scenario, but suggest the efficiency of planet re-inflation may be lower than previously theorized. Finally, we discuss the agreement within 10% of stellar masses and radii, and planet masses, radii, and orbital periods of both systems and speculate that this may be due to selection bias in searching for planets around evolved stars.Comment: 18 pages, 15 figures, accepted to AJ. Figures 11, 12, and 13 are the key figures of the pape

Evaluación mediante teledetección del efecto de canalizaciones sobre el humedal del Saladillo, Argentina

Los humedales son ecosistemas naturales cuya dinámica está determinada principalmente por la presencia de agua. Generalmente se los identifica como áreas que se inundan temporariamente donde el agua subterránea aflora en la superficie, o con áreas con suelos de baja permeabilidad que permanecen cubiertos por agua poco profunda. El agua, por lo tanto, juega un rol fundamental en la determinación de su estructura y funciones ecológicas. Los datos provistos por imágenes satelitales son una herramienta apropiada para analizar humedales y los cambios ocurridos en ellos a lo largo del tiempo. Los Bañados del Saladillo son un complejo de humedales en el centro de Argentina, de gran importancia para la preservación de aves acuáticas. Estos bañados han sufrido profundos cambios por el avance de la agricultura y las canalizaciones realizadas para mitigar el efecto de inundaciones en el sudeste de la provincia de Córdoba de este país. El objetivo del trabajo fue conocer la condición histórica y presente de los Bañados del Saladillo, y analizar los efectos de las canalizaciones sobre los mismos. Se estudiaron 6 imágenes satelitales que se clasificaron con ENVI 4.8 (ITT, 2010), representando la estación seca y húmeda en tres períodos: previo a las canalizaciones (1996); posterior a las canalizaciones (2004-2006); período reciente (2010-2011). Éstas fueron seleccionadas de acuerdo a las precipitaciones acumuladas en 6 meses previos para que fueran comparables. El área de lagunas se redujo entre un 70% (estación húmeda) y un 33% (estación seca). Los mayores cambios observados en la estación húmeda se reflejaron también en la reducción del número de lagunas (40%), la variabilidad de su tamaño (66%), el perímetro de las mismas (28%) y el incremento de la distancia entre ellas. Más allá de la mitigación de las inundaciones, las canalizaciones favorecieron el avance de la agricultura sobre áreas históricamente inundadas en la estación lluviosa, poniendo en riesgo la persistencia de este importante humedal del sudeste de Córdoba en el centro de Argentina. Los resultados obtenidos representan una herramienta útil al momento de tomar decisiones para el manejo y conservación de estos relictos de hábitat natural y su biodiversidad.Wetlands are natural ecosystems whose dynamics is mainly determined by the presence of water. They are generally identified as temporarily flooded areas where groundwater emerges at the surface, or areas with low permeability soils that remain covered by shallow water. The water, therefore, plays a key role in determining the structure and ecological functions of wetlands. Data provided by satellite images are an appropriate tool for analyzing wetlands and their changes over time. The Saladillo Wetlands are a complex of marshlands in the centre of Argentina, of great importance to the preservation of birds. These marshes have suffered profound changes caused by the advancement of agriculture and channels made to mitigate the effects of flooding in the southeast of the province of Cordoba in this country. The objective of our work was to know the historical and present condition of the Saladillo Wetlands, and to analyze the effects of the channelization on them. We studied six satellite images classified with ENVI 4.8. These images represented the dry and the wet season into three periods: prior to the channelization (1996), after the channelization (2004-2006); and recent period (2010- 2011). They were selected according to the accumulated rainfall during the previous 6 months to make them comparable. The pond area was reduced by 70% (wet season) and 33% (dry season). The major changes observed in the wet season also reflected in the reduction in the number of ponds (40%), the variability of their size (66%), the perimeter of flooded areas (28%) and an increasing the distance between ponds. Beyond the flood mitigation, the channelization favoured the advancement of agriculture on areas historically flooded in the rainy season, threatening the persistence of this important wetland of the southeast of Cordoba in central Argentina. Our results represent a useful tool for the management and conservation of these remnants of natural habitat and biodiversity.Fil: Lopez, C.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; ArgentinaFil: Brandolin, Pablo Germán. Asociación Civil Amigos para la Conservación de las Aves, Córdoba; ArgentinaFil: Campanella, O. R.. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia; ArgentinaFil: Martino, A. L.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; ArgentinaFil: de Angelo, Carlos Daniel. Universidad Nacional de Misiones. Facultad de Ciencias Forestales. Instituto de Biologia Subtropical - Sede Puerto Iguazu; Argentin

Multi-task multiple kernel machines for personalized pain recognition from functional near-infrared spectroscopy brain signals

Currently there is no validated objective measure of pain. Recent neuroimaging studies have explored the feasibility of using functional near-infrared spectroscopy (fNIRS) to measure alterations in brain function in evoked and ongoing pain. In this study, we applied multi-task machine learning methods to derive a practical algorithm for pain detection derived from fNIRS signals in healthy volunteers exposed to a painful stimulus. Especially, we employed multi-task multiple kernel learning to account for the inter-subject variability in pain response. Our results support the use of fNIRS and machine learning techniques in developing objective pain detection, and also highlight the importance of adopting personalized analysis in the process.Comment: International Conference on Pattern Recognition (ICPR

All Six Planets Known to Orbit Kepler-11 Have Low Densities

The Kepler-11 planetary system contains six transiting planets ranging in size from 1.8 to 4.2 times the radius of Earth. Five of these planets orbit in a tightly-packed configuration with periods between 10 and 47 days. We perform a dynamical analysis of the system based upon transit timing variations observed in more than three years of \ik photometric data. Stellar parameters are derived using a combination of spectral classification and constraints on the star's density derived from transit profiles together with planetary eccentricity vectors provided by our dynamical study. Combining masses of the planets relative to the star from our dynamical study and radii of the planets relative to the star from transit depths together with deduced stellar properties yields measurements of the radii of all six planets, masses of the five inner planets, and an upper bound to the mass of the outermost planet, whose orbital period is 118 days. We find mass-radius combinations for all six planets that imply that substantial fractions of their volumes are occupied by constituents that are less dense than rock. The Kepler-11 system contains the lowest mass exoplanets for which both mass and radius have been measured.Comment: 39 pages, 10 figure