La caza de materia oscura en rayos-gamma con Fermi-LAT y CTA: modelado, predicciones y análisis en varios objetos astrofísicos

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de Lectura: 25-11-2022Gravitational evidences at diferent cosmological scales hint towards the existence of a dark component of the Universe, which amounts up to the 85% of its matter density. Despite all the eforts, the dark matter (DM) has eluded any clear detection and its ultimate nature remains still unknown. The current knowledge suggests that the DM cannot be identifed with the particles comprised in the Standard Model (SM). In this context, the Weakly Interacting Massive Particles (WIMPs) provide a framework that naturally yields the measured DM relic density, while at the same time they are expected to interact with SM particles. From these interactions, one of the most promising channels are γ-rays, which travel the Universe without defection, pointing back towards its original source. This Thesis has been devoted to unveil the unknown properties of the dark matter focusing on the so-called γ-ray indirect DM searches. We have conducted an exhaustive study of the DM contents and distribution in diferent interesting astrophysical objects and computed the state-of-the-art predictions for their annihilation and decay DM fuxes. Then, we have used these models to both, perform searches in existing F ermi-LAT data and obtain the prospects for the future Cherenkov Telescope Array (CTA). In the absence of detection, we proceed to a systematic search starting with galaxy clusters, known to be very good candidates to search DM emission. We compute the sensitivity to difuse γ-ray emission from Perseus, one of the most massive local galaxy clusters, of the future CTA, including in the analysis the CR-induced γ-rays as a background in a template ftting analysis. Staying with galaxy clusters, we then use 12 years of Fermi-LAT data from nearly 50 local galaxy clusters, searching for a DM-induced γ-ray signal, modelled including the expected substructures. We also explore introducing new targets in the quest of DM. For this, we perform the frst DM γ-ray search in dwarf irregular galaxies (dIrrs) using Fermi-LAT data. Finally, we collect the results of the previous studies to model the DM content of a subsample of objects that we have already investigated (dIrrs and clusters) and also of representative dark subhalos of the Milky Wa

DUE DILIGENCE AND DECENT WORK. SPECIAL REFERENCE TO LABOUR LEGISLATION IN VALUE CHAINS

In recent decades, the agricultural world has changed, in this new context, international food companies are organized around a global production network. One of the main factors for the introduction of a more decentralized and flexible food and agricultural system was the wage gap between actors from the Global North and the Global South. This study analyzes the effectiveness of the action of control mechanisms in relation to the protection of workers' rights in multinational companies in Spain with special reference to the value chain of the agricultural sector. In particular, the working conditions of workers in food companies will be analyzed, analyzing the inequalities between the different groups of workers, paying special attention to immigrants and women, thus analyzing possible differences, contractual irregularities and salary gaps. Therefore, the article invites us to reflect on the need to implement new control mechanisms and regulatory instruments that intervene to correct the distortions in the agricultural labor market and the imbalances in the working conditions of these groups with the aim of contributing to a transformation of agricultural work through social strategies

Revisiting the liver: from development to regeneration - what we ought to know!

The liver is structurally and functionally heterogeneous and complex, and it accomplishes crucial functions for the organism. Its most remarkable potential is its capacity to regenerate after injury in order to maintain whole body homeostasis and guarantee the survival of the individual. Under normal conditions, liver regeneration (LR) is attributed to adult hepatocytes, the main cells in the liver which are able to proliferate in response to different stimuli or injuries. Nevertheless, when liver injury is severe and/or hepatocytes are prevented from proliferation, liver stem/progenitor cells (LS/PCs) participate directing LR to maintain liver mass and functions. Different mechanisms have been shown to guide this second line of LR, such as intrahepatic and extrahepatic liver progenitor cells, as well as transdifferentiation processes between hepatocytes and other liver cells. For this reason, many efforts have been made to elucidate the specific molecular mechanisms which orchestrate this process; this in turn would improve the prognosis and treatment of liver diseases. In this review, we revisit the fascinating process of LR, also with a short overview about liver development, the process from which arises the concept of LS/PCs participating in LR, and very important nowadays when considering cell therapy and tissue bioengineering for the treatment of patients suffering from liver disease

La relectura institucional del trabajo autónomo. Un estudio de sus manifestaciones normativas

[ES]El Estatuto del Trabajador Autónomo nació ante una realidad más que evidente: el vertiginoso crecimiento del colectivo de los autónomos y, por el contrario, la dispersión normativa en la regulación de su régimen, así he considerado de interés realizar un estudio sobre este colectivo, centrándome en la novedosa figura del trabajador autónomo económicamente dependient

Nivel de conocimiento de los tecnólogos médicos en el área de radiología, sobre la ley Nº 28028 en: Hospital Nacional "Luis N. Sáenz" PNP (Castrense); Hospital Nacional Dos de Mayo (MINSA); Hospital Nacional Guillermo Almenara Irigoyen (EsSalud) y Clínica Particular (SANNA) en el año 2015

La presente investigación es de tipo observacional, descriptiva. Es prospectivo y de acuerdo al periodo y secuencia del estudio es transversal. Se utiliza como instrumento un cuestionario con la finalidad de recolectar información específica. El cuestionario es aplicado a una muestra de 60 tecnólogos médicos en el área de radiología para determinar el grado de conocimiento sobre la ley Nº 28028. Los resultados revelan que el 38,3% (23) tecnólogos médicos en el área de radiología tienen un conocimiento medio sobre las disposiciones generales de la ley 28028 - Ley de Regulación del Uso de Fuentes de Radiación Ionizante, un 51,7% (31) tienen un conocimiento medio sobre las autorizaciones de la ley28028, un 51,7% (31) tienen un conocimiento alto sobre las inspecciones de la ley, un 65% (39) tienen un conocimiento medio sobre el régimen sancionador de la ley 28028, un 60% (36) tienen un conocimiento medio sobre los derechos e ingresos de la ley 28028.Tesi

El metaverso como forma de trabajo. Riesgos, y oportunidades. : Una mirada al derecho internacional

This paper analyzes the legal aspects that we will find from now on in the labor framework with the arrival of new forms of work in the digital age and specifically with the arrival of the metaverse. Hand in hand with the evolution of the labor relations system, the concern of the legislator arises to respond to the new reality and it is with the arrival of all these novelties that a multitude of legal issues also arise, such as: the place from which the services are provided, the type of employment contract, the application of legislation regarding the prevention of occupational hazards, the emergence of new gaps or the role of punitive labor law, among others.El presente artículo analiza los aspectos jurídicos que encontraremos a partir de ahora en el marco laboral con la llegada de las nuevas formas de trabajo en la era digital y en concreto con la llegada del metaverso. De la mano de la evolución del sistema de relaciones laborales surge la preocupación del legislador por dar respuesta a la nueva realidad y es con la llegada de todas estas novedades que surgen también multitud de cuestiones legales a tener en cuenta como pueden ser: el lugar desde el que se prestan los servicios, la modalidad del contrato de trabajo, la aplicación de la legislación referente a la prevención de riesgos laborales, el surgimiento de nuevas brechas o el papel del derecho laboral sancionador entre otros

Promoting Social Competence in Preschool with an Executive Functions Program Conducted by Teachers

The objective of this research is to examine the effectiveness of the “Executive Function Training Program in Preschool” (EFE-P) that includes real-world activities and applies different required methodologies for a sustainable education. In addition, it is evaluated whether the improvement of executive functions is transferred to the social competence domain. The study involved 100 students aged 5–6 years, of which 50 were randomly assigned to the active control group and 50 to the experimental group. Executive functions (BRIEF-P) and social competence (BASC and PKBS-2) were measured at two time points (pre-intervention and post-intervention). Data were analyzed using the Generalized Estimating Equation (GEE) for repeated data and results showed that children in the experimental group obtained better scores on executive functions and social competence compared to their peers in the control group. It is discussed if the executive functions training can be effective in improving social competence as long as the programs include real-world activities that encourage such transfer, as the EFE-P does

Constraining the dark matter contribution of γ rays in clusters of galaxies using Fermi -LAT data

Clusters of galaxies are the largest gravitationally bound systems in the Universe. Their dynamics are dominated by dark matter (DM), which makes them among the best targets for indirect DM searches. We analyze 12 years of data collected by the Fermi Large Area Telescope (Fermi-LAT) in the direction of 49 clusters of galaxies selected for their proximity to the Earth and their high x-ray flux, which makes them the most promising targets. We first create physically motivated models for the DM density around each cluster considering different assumptions for the substructure distribution. Then we perform a combined search for a γ-ray signal in the Fermi-LAT data between 500 MeV and 1 TeV. We find a signal of γ rays potentially associated with DM that is at a statistical significance of 2.5σ-3.0σ when considering a slope for the subhalo mass distribution α=1.9 and minimum mass of Mmin=10-6M⊙. The best-fit DM mass and annihilation cross sections for a bb¯ annihilation channel are mχ=40-60 GeV and (σv)=(2-4)×10-25 cm3/s. When we consider α=2.0 and Mmin=10-9M⊙, the best fit of the cross section reduces to (σv)=(4-10)×10-26 cm3/s. For both DM substructure models there is a tension between the values of (σv) that we find and the upper limits obtained with the nondetection of a γ-ray flux from Milky Way dwarf spheroidal galaxies. This signal is thus more likely associated with γ rays produced in the intracluster region by cosmic rays colliding with gas and photon fieldsM. D. M.’s research is supported by Fellini—Fellowship for Innovation at INFN, funded by the European Union’s Horizon 2020 research programme under the Marie Sklodowska-Curie Cofund Action, Grant Agreement No. 754496. J. P. R.’s work is supported by Grant No. SEV-2016-0597-17-2 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future.” M. A. S. C. was also supported by the Atracción de Talento Contracts No. 2016-T1/TIC-1542 and No. 2020- 5A/TIC-19725 granted by the Comunidad de Madrid in Spain. The work of J. P. R. and M. A. S. C. was additionally supported by the Grants No. PGC2018-095161-B-I00, No. PID2021-125331NB-I0

Constraining the dark matter contribution of γ\gamma rays in Cluster of galaxies using Fermi-LAT data

Clusters of galaxies are the largest gravitationally-bound systems in the Universe. Their dynamics are dominated by dark matter (DM), which makes them among the best targets for indirect DM searches. We analyze 12 years of data collected by the Fermi Large Area Telescope (Fermi-LAT) in the direction of 49 clusters of galaxies selected for their proximity to the Earth and their high X-ray flux, which makes them the most promising targets. We first create physically motivated models for the DM density around each cluster considering different assumptions for the substructure distribution. Then we perform a combined search for a $\gamma$-ray signal in the {\it Fermi}-LAT data between 500 MeV and 1 TeV. We find a signal of $\gamma$ rays potentially associated with DM that is at a statistical significance of $2.5\sigma-3.0\sigma$ when considering a slope for the subhalo mass distribution $\alpha=1.9$ and minimum mass of $M_{\rm{min}}=10^{-6}$ $M_{\odot}$. The best-fit DM mass and annihilation cross-sections for a $b\bar{b}$ annihilation channel are $m_{\chi}=40-60$ GeV and $\langle \sigma v \rangle = (2-4) \times 10^{-25}$ cm$^3$/s. When we consider $\alpha=2.0$ and $M_{\rm{min}}=10^{-9}$ $M_{\odot}$, the best-fit of the cross section reduces to $\langle \sigma v \rangle = (4-10) \times 10^{-26}$ cm$^3$/s. For both DM substructure models there is a tension between the values of $\langle \sigma v \rangle$ that we find and the upper limits obtained with the non-detection of a $\gamma$-ray flux from Milky Way dwarf spheroidal galaxies. This signal is thus more likely associated with $\gamma$ rays produced in the intracluster region by cosmic rays colliding with gas and photon fields.Comment: 27 Pages, 13 Figures. Accepted for publication in the PRD journa