Properties of ultra-cool dwarfs with Gaia. An assessment of the accuracy for the temperature determination

We aimed to assess the accuracy of the Gaia teff and logg estimates as derived with current models and observations. We assessed the validity of several inference techniques for deriving the physical parameters of ultra-cool dwarf stars. We used synthetic spectra derived from ultra-cool dwarf models to construct (train) the regression models. We derived the intrinsic uncertainties of the best inference models and assessed their validity by comparing the estimated parameters with the values derived in the bibliography for a sample of ultra-cool dwarf stars observed from the ground. We estimated the total number of ultra-cool dwarfs per spectral subtype, and obtained values that can be summarised (in orders of magnitude) as 400000 objects in the M5-L0 range, 600 objects between L0 and L5, 30 objects between L5 and T0, and 10 objects between T0 and T8. A bright ultra-cool dwarf (with teff=2500 K and \logg=3.5 will be detected by Gaia out to approximately 220 pc, while for teff=1500 K (spectral type L5) and the same surface gravity, this maximum distance reduces to 10-20 pc. The RMSE of the prediction deduced from ground-based spectra of ultra-cool dwarfs simulated at the Gaia spectral range and resolution, and for a Gaia magnitude G=20 is 213 K and 266 K for the models based on k-nearest neighbours and Gaussian process regression, respectively. These are total errors in the sense that they include the internal and external errors, with the latter caused by the inability of the synthetic spectral models (used for the construction of the regression models) to exactly reproduce the observed spectra, and by the large uncertainties in the current calibrations of spectral types and effective temperatures.Comment: 18 pages, 17 figures, accepted by Astronomy & Astrophysic

The invariator Design: An update

The invariator is a method to generate a test line within an isotropically oriented plane through a fixed point, in such a way that the test line is effectively motion invariant in three dimensional space. Generalizations exist for non Euclidean spaces. The invariator design is convenient to estimate surface area and volume simultaneously. In recent years a number of new results have appeared which call for an updated survey. We include two new estimators, namely the a posteriori weighting estimator for surface area and volume, and the peak-and-valley formula for surface area

New rotational integrals in space forms, with an application to surface area estimation

A surface area estimator for three-dimensional convex sets, based on the invariator principle of local stereology, has recently motivated its generalization by means of new rotational Crofton-type formulae using Morse theory. We follow a different route to obtain related formulae which are more manageable and valid for submanifolds in constant curvature spaces. As an application, we obtain a simplified version of the mentioned surface area estimator for non-convex sets of smooth boundary.Work was supported by the UJI project P11B2012-24 and the PROMETEOII/2014/062 project

Stereology with cylinder probes

Intersection formulae of Croton type for general geometric probes are well known in integral geometry. For the special case of cylinders with non necessarily convex direktrix, however, no equivalent formula seems to exist in the literature. We derive such formula resorting to motion invariant probability elements associated with test systems, instead of using a traditional approach. Because cylinders are seldom used as probes in stereological practice, however, this note is mainly of a theoretical nature

El derecho de reparación a las víctimas en el derecho internacional : un estudio comparativo entre el derecho internacional de responsabilidad estatal y los principios básicos de reparación de víctimas de derechos humanos

En este artículo se analizan los textos más importantes en el ámbito de reparación a las víctimas en el ámbito internacional y que reflejan las características esenciales tanto del derecho internacional de responsabilidad estatal como del derecho internacional de los derechos humanos. Por un lado, los Artículos sobre la Responsabilidad del Estado por hechos internacionalmente ilícitos, adoptados por la Comisión de Derecho Internacional de las Naciones Unidas en 2001. Por otro lado, los Principios y Directrices Básicos sobre el Derecho de las Víctimas de Violaciones Manifiestas de las Normas Internacionales de Derechos Humanos y de Violaciones Graves del Derecho Internacional Humanitario a Interponer Recursos y Obtener Reparaciones, aprobados por la Asamblea General de las Naciones Unidas en 2005. Estos textos articulan, cada uno en su ámbito, aquellos principios que han sido aplicados en el los tribunales internacionales y que gozan de un amplio consenso en el derecho internacional. El objetivo del artículo es identificar los elementos comunes así como los elementos característicos de cada uno de ellos, en orden a mostrar sus logros y deficiencias a la hora de reparar a las víctimas de violaciones de derechos humanos

An Optimisation Algorithm to Establish the Location of Stations of a Mixed Fleet Biking System: An Application to the City of Lisbon

AbstractThis paper presents the design and deployment of a bike-sharing system developed for Lisbon. The design of this new service is performed through an heuristic, encompassing a Mixed Integer Linear Program (MILP), that simultaneously optimise the location of shared biking stations, the fleet dimension and measuring the bicycle relocation activities required in a regular operation day. The results obtained for the several tested scenarios provided better insights into knowing how to improve the design and operation of these systems

Temporal evolution and associated factors of adherence to mammography screening among women in Spain: results from two national health surveys (2017–2020)

Ensuring equity in cancer screening is recommended by the European Commission. Despite the fact that breast cancer screening is a free population-based program in Spain, there remains considerable variation in the adherence to screening rate among population groups. This study was designed to describe the adherence of breast cancer screening in women in Spain, to evaluate the evolution in the period from 2017 to 2020, and to determine the variables that influence choosing to undergo breast cancer screening. A nationwide cross-sectional study with 7220 females aged 50–69 years from the 2017 Spanish National Health Survey and the 2020 European Health Survey for Spain was performed. We investigated mammography uptake rates, with socio-demographic factors, lifestyle habits, and health-related characteristics as independent variables. Multivariable logistic regression was used to identify the associated factors of mammography adherence. Of the women, 78% had undergone mammography in the previous two years, and there was a significant decrease in the uptake rate for breast cancer screening from 2017 (81.23%) to 2020 (74.68%) (p < 0.001). Educational level, marital status, residential location, nationality, smoking status, alcohol consumption, and leisure-time physical activity were all associated factors of mammography uptake