80 research outputs found
Estudio Monte Carlo sobre la calibración en energía para el experimento Argon Dark Matter (Monte Carlo studies about the energy calibration for the Argon Dark Matter) experiment
The aim of the present work is the study of the energy calibration with external radioactive sources for the Argon Dark Matter (ArDM) experiment, which consists of a double-phase argon detector for direct dark matter searches. This experiment, with a ton-scale sensitive volume, has been conceived to detect nuclear recoils produced by dark matter particles scattering off target nuclei. The advantage of having a double-phase detection technique lies on the fact that both scintillation light and ionization charge can be measured, providing a powerful discrimination method between nuclear recoils and background events. In this context, the calibration with external gamma sources is necessary in order to establish the energy scale, monitoring at the same time the detector stability. In the introduction we briefly present the different experimental evidences of dark matter and the requirements that a good particle candidate should fulfill according to the astrophysical observations.
Moreover, we will introduce the supersymmetry, the extension of the Standard Model of particles which provides one WIMP candidate called neutralino. Throughout the following sections, special attention will be dedicated to the different techniques used for dark matter detection, pointing out the ArDM detector concept and technology. Finally, the simulation software and the results of the energy calibration studies will be presented
Análisis de la primera toma de datos subterránea y estudios de fondo del experimento Argon Dark Matter
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física Atómica, Molecular y Nuclear, leída el 03/06/2016Dark Matter is a collisionless and non-luminous kind of matter, whose existence is inferred through its gravitational effects at the galactic, cluster and large scales in the Universe. From the analysis of the PLANCK latest data, Dark Matter accounts for the 26.6% of the composition of the energy density of the Universe, while ordinary matter only represents 4.9% [1]. Revealing the nature of Dark Matter has become one of the most challenging problems in modern physics. A possible explanation comes from particle physics in the form of Weakly Interacting Massive Particles (WIMPs) , a particularly interesting class of new particle that can naturally account for the measured abundance of Dark Matter. WIMPs would be produced thermally in the early Universe and, since they interact only weakly, their annihilation rate would become insignificant as the Universe expands, thus freezing out with a relic abundance. Supersymmetry, an extension of the Standard Model of particle physics, foresees interesting possible WIMP candidates in the form of the Lightest Supersymmetric Particle ( LSP) , which is neutral, stable and massive. A great experimental effort has been undertaken in the last years to detect Dark Matter in underground and space-based detectors or produce it in accelerators. This Thesis is focused on the analysis of the first underground run and background studies of the Argon Dark Matter (ArDM) experiment, which aims to detect WIMPs via the nuclear recoils produced by their elastic scattering off argon nuclei. The detector is a ton-scale double-phase (liquid-gas) TPC, which is currently installed at the Canfranc Underground Laboratory ( LSC) under the Pyrenees in Spain and it is the first ton-scale argon detector for Dark Matter to take data underground...La Materia Oscura es un tipo ele materia no luminosa y sin colisiones cuya existencia es inferida a través de sus efectos gravitacionales en la escala galáctica, de cúmulos de galaxias y a grandes escalas en el Universo. De acuerdo con el análisis de los datos más recientes de PLANCK, la Materia Oscura da cuenta del 26,6% de la composición de la densidad de energía del Universo, mientras que la materia ordinaria sólo representa un 4,9% [1]. Revelar la naturaleza de la Materia Oscura se ha convertido en uno de los problemas más desafiantes de la física moderna. Una posible explicación proviene de la física de partículas en la forma de Partículas Masivas Débilmente Interactuantes (WIMPs), una nueva clase de partícula especialmente interesante que puede dar cuenta de forma natural de la abundancia medida de Materia Oscura. Los WIMPs se producirían térmicamente en el Universo primitivo y, puesto que sólo interaccionan débilmente, su tasa de aniquilación se convertiría en insignificante conforme el Universo se expande, permaneciendo así con una abundancia determinada. Supersimetría, una extensión del Modelo Estándar de partículas, proporciona candidatos a WIMPs en forma de la Partícula Supersimétrica Más Ligera (LSP), que es neutra, estable y masiva. Un gran esfuerzo experimental ha sido realizado en los últimos años para detectar Materia Oscura con detectores subterráneos o espaciales o para producirla en aceleradores. Esta Tesis está centrada en el análisis de la primera toma de datos subterránea y estudios de fondo del experimento Argon Dark Matter (ArDM), cuyo objetivo es detectar WIMPs a través de los retrocesos nucleares producidos por su dispersión elástica por núcleos de argón. El detector, actualmente instalado en el Laboratorio Subterráneo de Canfranc (LSC) bajo los Pirineos en España, es una TPC de doble fase (líquido-gas) de una tonelada y es el primer detector de Materia Oscura basado en argón de la escala de la tonelada en tomar elatos en un laboratorio subterráneo...Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEunpu
Hands on XENON100 Dark Matter (DM) direct detection experiment: studying and modeling background and signal in a frequentist analysis framework
In this activity we try to reproduce the XENON100 direct dark matter search results from 224 live days of data taken between February 2011 and March 2012. The statistical approach to model signal and background in the profile likelihood analysis is presented and the procedure used by the XENON100 collaboration to interpret the results is partially implemented
Gravitational collapse in f(R) theories
We study the gravitational collapse in modified gravitational theories. In particular, we analyze a general f(R) model with uniformly collapsing cloud of self-gravitating dust particles. This analysis shares analogies with the formation of large-scale structures in the early Universe and with the formation of stars in a molecular cloud experiencing gravitational collapse. In the same way, this investigation can be used as a first approximation to the modification that stellar objects can suffer in these modified theories of gravity. We study concrete examples, and find that the analysis of gravitational collapse is an important tool to constrain models that present late-time cosmological acceleration
More trees with your coffee? Diversity and habitat associations of terrestrial medium- and large-sized mammals in shade-grown coffee plantations of the highlands of Guatemala
Agricultural practices can have detrimental impacts on biodiversity, but some studies have shown the benefits of agroforestry practices like shade-grown coffee to bird communities and, to a lesser extent, to mammal communities. To better understand whether shade-grown coffee plantations can contribute to the conservation of mammal communities, we deployed camera traps in private reserves with a matrix of shade-grown coffee plantations and forest in the highlands of Guatemala. At each reserve we estimated species richness of terrestrial medium- and large-sized mammals. We also estimated mammal relative abundance and occupancy probabilities as proxies for mammalian habitat associations and evaluated how these were affected by key landscape features (e.g., land-use type, asphalt roads, and distance to protected areas). We used hierarchical multi-species Bayesian abundance models that account for imperfect detection to estimate our parameters of interest and model the influence of landscape features on site-level species richness and species relative abundance. We detected 14 species across all reserves and found a strong influence of land use and presence of asphalt roads on mammalian relative abundances and species richness. More species used areas around the camera traps in forest than in shade-grown coffee plantations and far from asphalt roads. Our study shows that reserves with shade-grown coffee plantations can harbor terrestrial mammalian communities of conservation interest. Our results also suggest that to maintain mammalian diversity and abundances in our study area, shade-grown coffee crops should be mixed in with natural forests and the presence of asphalt roads within these should be avoided or minimized.Las prácticas agrícolas pueden tener impactos perjudiciales en la biodiversidad, pero algunos estudios han demostrado beneficios de prácticas agroforestales, como el café bajo sombra, para comunidades de aves y, en menor medida, comunidades de mamíferos. Para entender mejor si las plantaciones de café bajo sombra pueden contribuir a la conservación de comunidades de mamíferos, colocamos cámaras trampa en reservas privadas con plantaciones de café bajo sombra y bosque en el altiplano de Guatemala. En cada reserva estimamos la riqueza de especies de mamíferos medianos y mayores. También estimamos la abundancia relativa y probabilidad de ocupación como aproximaciones a las asociaciones de hábitat de mamíferos y evaluamos cómo estas son afectadas por características clave de paisaje (p.ej. tipo de uso de suelo, carreteras y distancia a áreas protegidas). Utilizamos modelos jerárquicos bayesianos multiespecies de abundancia que consideran que la detección de especies es imperfecta para estimar nuestros parámetros de interés y modelar la influencia de características del paisaje en la riqueza y abundancia relativa de especies a nivel de sitio. Detectamos 14 especies en todas las reservas y encontramos una fuerte influencia del uso de la tierra en la abundancia relativa y la riqueza de especies de mamíferos. Más especies utilizaron áreas cercanas a las cámaras trampa en el bosque que a las plantaciones de café bajo sombra y lejos de carreteras. Nuestro estudio demuestra que las plantaciones de café bajo sombra pueden albergar comunidades de mamíferos terrestres de interés para la conservación. Nuestros resultados también sugieren que para mantener la diversidad y abundancia de mamíferos en el área de estudio, las plantaciones de café bajo sombra deben estar mezcladas con bosques nativos diversos, así como que la presencia de carreteras debe ser evitada o reducida
Aproximación al riesgo psicosocial del burnout. Estudio de los factores implicados en el burnout en profesores de secundaria.
El tema tratado en el presente estudio teórico-práctico es el Burnout o Síndrome de estar quemado en el trabajo (SQT). En cuanto al trabajo de campo se realiza un estudio bibliográfico sobre este síndrome. En primer lugar, se exponen los diversos factores y riesgos psicosociales y se ofrece una explicación más extensa sobre el trastorno, su comparativa respecto al estrés laboral y su origen para una mejor comprensión. Además, en el desarrollo del burnout se encuentran algunos elementos que influirán de manera determinada, aunque para prevenir su aparición se tendrán que tener en cuenta una serie de estrategias de afrontamiento nombradas también en el trabajo. Tras el análisis, se realiza una investigación en profesores de educación secundaria sobre el burnout y la influencia de determinadas variables independientes sobre el mismo. Finalmente, se propondrá una reflexión sobre todo ello y la conveniencia de adoptar medidas de prevención y afrontamiento del burnout
Hands on XENON100 Dark Matter (DM) direct detection experiment: studying and modeling background and signal in a frequentist analysis framework
In this activity we try to reproduce the XENON100 direct dark matter search results from 224 live days of data taken between February 2011 and March 2012. The statistical approach to model signal and background in the profile likelihood analysis is presented and the procedure used by the XENON100 collaboration to interpret the results is partially implemented
Scaling Up the Family Integrated Care Model in a Level IIIC Neonatal Intensive Care Unit: A Systematic Approach to the Methods and Effort Taken for Implementation
Background: Family Integrated Care (FICare) integrates parents in the direct care of their child while the healthcare personnel act as teachers and guides. To this date, most reports on the feasibility of this model refer to stable preterm infants admitted to Neonatal Intensive Care Units (NICUs).Objectives: To scale up and adapt FICare to make it suitable in level IIIC NICUs, which care for extreme prematurity and other complex medical or surgical neonatal conditions.Materials and Methods: Step 1 was the creation of the FICare implementation team (FICare-IT) and baseline analysis of current procedures for critical care to identify needs, wishes, and requirements; we aimed for protocol elaboration tailored to our cultural, architectural, and clinical context (March 2017 to April 2018). Step 2 as a dissemination strategy by FICare-IT acting as primary trainers and mentors to ensure the education of 90% of nursing staff (May 2018 to July 2018). Step 3 involved piloting and evaluation with the aim to refine the procedure (July 2018 to December 2020).Results: A rigorous but flexible protocol was edited. The FICare educational manual included two curricula: for healthcare professionals/staff (Training the trainers) and for families (Education of caregivers), the latter being categorized in two intervention levels (basic and advanced), depending on the infant care needs and parent's decision. In total, 76 families and 91 infants (74.7% preterm; 18.7% complex surgery; 6.6% others) were enrolled in the pilot. No differences in acceptance rate (overall 86.4%) or in the number of infant-family dyads in the program per month were observed when considering the pre- and post-Covid-19 pandemic periods. All families, except for one who dropped out of the program, completed the agreed individualized training. Mothers spent more time in NICU than fathers (p < 0.05); uninterrupted time spent by mothers in NICU was longer during the pre-pandemic period (p < 0.01). Observed time to reach proficiency by task was within the expected time in 70% of the program contents. The parents revealed educational manuals, workshops, and cot-side teaching sessions as essential for their training, and 100% said they would accept entry into the FICare program again.Conclusions: The principles of the FICare model are suitable for all levels of care in NICUs. Leadership and continuous evaluation/refinement of implementation procedures are essential components to achieve the objectives
Type 2 diabetes mellitus burden of disease in Brazil between 1990 to 2019: a nationwide descriptive analysis of the Global Burden of Disease Study 2019
This is a Brazilian nationwide analysis of the burden of type 2 diabetes mellitus along the 26 states and federal district, between 1990 up to 2019. In summary, through spatiotemporal Gaussian regression methods, we estimated the attributable share of T2DM for prevalence, deaths, DALYs, YLLs and YLDs in Brazilian population. Moreover, we sought to investigate the behavior of top risk factors for T2DM and the attributable impact in burden of disease outcomes accordingly. We also investigated whether the geolocation and time, as well as the socio demographic index, would have any ecological relationship with different levels of disease and risk factors impact. In summary, our major conclusion is that, regardless of any trend pattern overtime, states out of the South/Southeast region in Brazil are more prone to higher burden of diseases attributable to T2DM. Given the ecological pattern with the SDI, it is fair to speculate that socio-economic structural and fundamental matters may be associated with burden of disease pattern (i.e., as high as the SDI, lower is the attributable burden of disease). Top risk factors such high-fasting plasma glucose or physical inactivity may be targeted by policy makers as a potential primary prevention strategy. Our understanding of this ecological analysis is that even though the HTA improvements achieved over 1990 to 2019, population-oriented health care strategies can emphasize socio determinants of health together with the patient-level care, targeting risk factors of relevance
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