Constraints On Holographic Cosmological Models From Gamma Ray Bursts

We use Gamma Ray Bursts (GRBs) data from Y. Wang (2008) to put additional constraints on a set of cosmological dark energy models based on the holographic principle. GRBs are among the most complex and energetic astrophysical events known in the universe offering us the opportunity to obtain information from the history of cosmic expansion up to about redshift of $z\sim 6$. These astrophysical objects provide us a complementary observational test to determine the nature of dark energy by complementing the information of data from Supernovas (e.g. Union 2.1 compilation). We found that the $\Lambda CDM$ model gives the best fit to the observational data, although our statistical analysis ($\Delta AIC$ and $\Delta BIC$) shows that the models studied in this work ("Hubble Radius Scale" and "Ricci Scale Q") have a reasonable agreement with respect to the most successful, except for the "Ricci Scale CPL" and "Future Event Horizon" models, which can be ruled out by the present study. However, these results reflect the importance of GRBs measurements to provide additional observational constraints to alternative cosmological models, which are mandatory to clarify the way in which the paradigm of dark energy or any alternative model is correct.Comment: 11 pages, 6 figures, 7 tables, poster presentation: Congreso Nacional de F\'isica, Manizales, Caldas, Colombia, 201

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Beliefs on health and self-care practices in young adults: biographical study of lifestyles

El abundante acceso a información y recomendaciones para el autocuidado de la salud a través de los medios de comunicación y los programas de salud pública no han logrado aumentar la adherencia de la población a estilos de vida saludables. A pesar de los avances en esta materia, las enfermedades no trasmisibles asociadas a estilos de vida insanos siguen siendo una epidemia a nivel mundial. Objetivo: Para comprender uno de los factores psicosociales relevantes para el autocuidado de la salud se estudió en profundidad las creencias de profesionales jóvenes chilenos sobre salud y sobre sus prácticas de autocuidado. Materiales y métodos: Mediante un estudio cualitativo basado en el paradigma fenomenológico y el método biográfico se analizó las historias de vida de 14 adultos jóvenes profesionales que trabajan en distintas áreas laborales. Resultado: En base a un análisis de contenido se muestra que los jóvenes manifiestan creencias favorables hacia un estilo de vida saludable, pero a nivel de sus prácticas de autocuidado ellos mantienen algunas conductas no saludables. Es así como, independientemente del conocimiento científico que manejan sobre salud, los jóvenes generan una estructura argumentativa personal que les permite autojustificar la inconsistencia entre sus creencias y sus prácticas de autocuidado. Conclusiones: Estos hallazgos plantean la necesidad de redirigir el foco de las intervenciones de promoción de estilos de vida saludables.The abundant access to information and recommendations for self-care for health through the media and public health programs have not managed to increase the adherence of the population to healthy lifestyles. Despite advances in this area, the non-communicable diseases associated with unhealthy lifestyles continue to be an epidemic worldwide. Objective: the beliefs of Chilean young professionals about health and self-care were studied in depth to understand one of the relevant psychosocial factors that affect health self-care. Materials and methods: through a qualitative study based on the phenomenological paradigm and the biographical method, the life stories of 14 Chilean young professional adults working in different work areas were analyzed. Results: based on a content analysis, young people show favorable beliefs towards a healthy lifestyle but, at the level of self-care practices, they maintain some unhealthy behaviors. This is how, reagardless of the scientific knowledge they handle about health, young people generate a personal argumentative structure that allows them to selfjustify the inconsistence between their beliefs and their self-care practices. Conclusions: These findings raise the need to redirect the focus of interventions promoting healthy lifestyles

Innovación en Nicaragua: análisis de la participación estudiantil de la Universidad Nacional Politécnica en el Rally Nacional de Innovación 2024

El estudio subraya el papel preponderante de la innovación para el desarrollo socioeconómico, destacando al Rally Nacional de Innovación (RNI) como una plataforma estratégica a nivel de país, para el posicionamiento de la comunidad estudiantil al frente de proyectos de innovación en atención a las necesidades contextuales. El artículo registra un estudio de caso bajo enfoque constructivista y hermenéutico, de corte transversal, sustentado en hallazgos de revisión documental, observación no participante y discusión grupal. Se implementó un muestreo no probabilístico por conveniencia a tres estratos de la población. Los resultados destacan la efectividad de las estrategias implementadas en las fases del evento, entre estas se destacan: la instauración de una comisión organizativa, la convocatoria personalizada a estudiantes y mentores y la gestión de recursos institucionales para la realización del evento. Estos factores, junto a la disposición y destreza del estudiantado, posicionaron a la UNP en dos segundos lugares a nivel nacional. Sin embargo, pese a la efectividad de estas prácticas, se identifican brechas institucionales a superar como la gestión del conocimiento producido durante el evento y el aseguramiento de la interdisciplinariedad durante la conformación de equipos. En conclusión, los actores ratifican que la participación en el RNI 2024 significó un espacio de aprendizaje con el que se fortaleció el desarrollo integral de los estudiantes, permitiéndoles colaborar con equipos multidisciplinarios en un entorno competitivo de respeto, aprendizaje y de constantes desafíos a nivel técnico y socioemocional. Finalmente, se recomiendan ocho acciones estratégicas para las futuras participaciones en este tipo de eventos

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Search for High-Mass Resonances Decaying to τν in pp Collisions at √s=13 TeV with the ATLAS Detector

A search for high-mass resonances decaying to τν using proton-proton collisions at √s=13 TeV produced by the Large Hadron Collider is presented. Only τ-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb−1. No statistically significant excess above the standard model expectation is observed; model-independent upper limits are set on the visible τν production cross section. Heavy W′ bosons with masses less than 3.7 TeV in the sequential standard model and masses less than 2.2–3.8 TeV depending on the coupling in the nonuniversal G(221) model are excluded at the 95% credibility level

Operation and performance of the ATLAS Tile Calorimeter in Run 1

The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report