107 research outputs found

    Evaluating pointing errors on ergodic capacity of DF relay-assisted FSO communication systems

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    Ergodic capacity of decode-and-forward (DF) relay-assisted free-space optical (FSO) communication systems when line of sight is available is analyzed over gamma-gamma fading channels with pointing errors. Novel closed-form approximate ergodic capacity expression is obtained in terms of the H-Fox function for a 3-way FSO communication system when the α-μ distribution to efficiently approximate the probability density function (PDF) of the sum of gamma-gamma with pointing errors variates is considered. Moreover, we present a novel asymptotic expression at high signal-to-noise ratio (SNR) for the ergodic capacity of DF relay-assisted FSO systems. The main contribution in this work lies in an in-depth analysis about the impact of pointing errors on the ergodic capacity for cooperative FSO systems. In order to maintain the same performance in terms of capacity, it is corroborated that the presence of pointing errors requires an increase in SNR, which is related to the fraction of the collected power at the receive aperture, i.e. A 0 . Simulation results are further demonstrated to confirm the accuracy and usefulness of the derived results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors wish to acknowledge the financial support given by Spanish MINECO Project TEC2012-32606

    A Bayesian Solution to the Behrens-Fisher problem

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    A simple solution to the Behrens–Fisher problem based on Bayes factors is presented, and its relation with the Behrens–Fisher distribution is explored. The construction of the Bayes factor is based on a simple hierarchical model, and has a closed form based on the densities of general Behrens–Fisher distributions. Simple asymptotic approximations of the Bayes factor, which are functions of the Kullback–Leibler divergence between normal distributions, are given, and it is also proved to be consistent. Some examples and comparisons are also presented.Open access funding provided by Universidad de Málaga/CBUA

    A bayesian approach for one-way ANOVA under unequal variances

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    In this report a Bayesian solution to the problem of testing the equality of the means of k independent normal populations with unknown and arbitrary variances is provided. An important issue in the solution of this problem is the determination of groups with equal means, often solved by multiple comparisons, which can lead to results that are difficult to interpret. In order to avoid this drawback, we propose to treat all possible alternatives existing in the alternative hypothesis by considering the set of all possible configurations of the set of k means. This idea is closely related to the statistical pro-blem of cluster analysis. This allows us to reformulate the testing problem in terms of model selection. A hierarchical model is proposed to compute the Bayes factor of all models, as well as the posterior probability of all the possible configurations. Some illustrative examples of the goodness of the proposed solution are presented.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Targeting L-type amino acid transporter 1 in innate and adaptive T cells efficiently controls skin inflammation

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    BACKGROUND: Psoriasis is a frequent inflammatory skin disease that is mainly mediated by IL-23, IL-1β, and IL-17 cytokines. Although psoriasis is a hyperproliferative skin disorder, the possible role of amino acid transporters has remained unexplored. OBJECTIVE: We sought to investigate the role of the essential amino acid transporter L-type amino acid transporter (LAT) 1 (SLC7A5) in psoriasis. METHODS: LAT1 floxed mice were crossed to Cre-expressing mouse strains under the control of keratin 5, CD4, and retinoic acid receptor-related orphan receptor γ. We produced models of skin inflammation induced by imiquimod (IMQ) and IL-23 and tested the effect of inhibiting LAT1 (JPH203) and mammalian target of rapamycin (mTOR [rapamycin]). RESULTS: LAT1 expression is increased in keratinocytes and skin-infiltrating lymphocytes of psoriatic lesions in human subjects and mice. LAT1 deletion in keratinocytes does not dampen the inflammatory response or their proliferation, which could be maintained by increased expression of the alternative amino acid transporters LAT2 and LAT3. Specific deletion of LAT1 in γδ and CD4 T cells controls the inflammatory response induced by IMQ. LAT1 deletion or inhibition blocks expansion of IL-17-secreting γ4+δ4+ and CD4 T cells and dampens the release of IL-1β, IL-17, and IL-22 in the IMQ-induced model. Moreover, inhibition of LAT1 blocks expansion of human γδ T cells and IL-17 secretion by human CD4 T cells. IL-23 and IL-1β stimulation upregulates LAT1 expression and induces mTOR activation in IL-17+ γδ and TH17 cells. Deletion or inhibition of LAT1 efficiently controls IL-23- and IL-1β-induced phosphatidylinositol 3-kinase/AKT/mTOR activation independent of T-cell receptor signaling. CONCLUSION: Targeting LAT1-mediated amino acid uptake is a potentially useful immunosuppressive strategy to control skin inflammation mediated by the IL-23/IL-1β/IL-17 axis.Funding This manuscript has been funded by grants SAF 2017-82886-R (FS-M) and SAF 2013-42850-R (MF) from the Spanish Ministry of Economy and Competitiveness; CAM (S2017/BMD-3671-INFLAMUNE-CM) from the Comunidad de Madrid (FS-M); CIBERCV, BIOIMID PIE13/041 from Instituto de Salud Carlos III and Fundación La Marató TV3 (20152330 31). The project leading to these results has also received funding from FUNDACIÓN BBVA A EQUIPOS DE INVESTIGACIÓN CIENTÍFICA 2018 and from “la Caixa” Banking Foundation under the project code HR17-00016 (FS-M), and from Agencia Estatal de Investigación, Fondo Europeo de Desarrollo Regional PI17/01972 (E.D).S

    COVID-19 vaccine effectiveness against hospitalization due to SARS-CoV-2: A test-negative design study based on Severe Acute Respiratory Infection (SARI) sentinel surveillance in Spain

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    Background: With the emergence of SARS-CoV-2, influenza surveillance systems in Spain were transformed into a new syndromic sentinel surveillance system. The Acute Respiratory Infection Surveillance System (SiVIRA in Spanish) is based on a sentinel network for acute respiratory infection (ARI) surveillance in primary care and a network of sentinel hospitals for severe ARI (SARI) surveillance in hospitals. Methods: Using a test-negative design and data from SARI admissions notified to SiVIRA between January 1 and October 3, 2021, we estimated COVID-19 vaccine effectiveness (VE) against hospitalization, by age group, vaccine type, time since vaccination, and SARS-CoV-2 variant. Results: VE was 89% (95% CI: 83-93) against COVID-19 hospitalization overall in persons aged 20 years and older. VE was higher for mRNA vaccines, and lower for those aged 80 years and older, with a decrease in protection beyond 3 months of completing vaccination, and a further decrease after 5 months. We found no differences between periods with circulation of Alpha or Delta SARS-CoV-2 variants, although variant-specific VE was slightly higher against Alpha. Conclusions: The SiVIRA sentinel hospital surveillance network in Spain was able to describe clinical and epidemiological characteristics of SARI hospitalizations and provide estimates of COVID-19 VE in the population under surveillance. Our estimates add to evidence of high effectiveness of mRNA vaccines against severe COVID-19 and waning of protection with time since vaccination in those aged 80 or older. No substantial differences were observed between SARS-CoV-2 variants (Alpha vs. Delta).The data of the study was originally collectedas part of the following projects run by the European Centre for Disease Prevention and Control:“Establishing Severe Acute Respiratory Infections (SARI) surveillance and performing hospital-based COVID-19 transmission studies”, “Developing an infrastructure and performing vaccine effectiveness studies for COVID-19 vaccines in the EU/EEA”, and the “Vaccine Effectiveness, Burden and Impact Studies(VEBIS) of COVID-19 and Influenza".S

    VISIONES DE LA EDUCACION FINANCIERA: Analisis y perspectivas.

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    Este libro es el resultado de un trabajo de investigación por parte de todos los autores quienes integraron los capítulos, por lo que agradecemos su confianza e interés para ser parte de este gran proyecto académico. Gracias a los enlaces de cada una de las Instituciones que aceptaron respaldar este libro: Marlen Rocío Reyes Hernández, Profesora-Investigadora de la Universidad Autónoma del Estado de México; Rogelio Valenzuela Díaz, Decano de la Facultad de Economía de la Universidad de Panamá; Samuel Alberto Moreno Peralta, Presidente del Colegio de Economistas de Panamá, a los miembros de la Asociación Mexicana de Especialistas en Educación Financiera, Asociación Valor México y la Federación de Economistas de la República Mexicana. Asimismo, hacemos una deferencia a los jóvenes talentosos que acompañaron en la coordinación del documento final, entrañables alumnos, becarios y amigos: Julio César Silva Vázquez y Alfredo Larry Vargas Hernández, que estamos convencidas que alcanzarán todas sus metas que se propongan en la vida. También es necesario reconocer a nuestras amadas familias que compartieron el tiempo de convivencia, para que lográramos la realización de este libroVisiones de la educación financiera: análisis y perspectivas es una obra que enmarca la importancia de la educación financiera en la sociedad en el contexto actual. Las decisiones que en este tema realiza un individuo pueden impactar positiva o negativamente su estabilidad económica por un periodo indeterminado, es aquí cuando la educación financiera actúa como una herramienta trascendental en su bienestar personal. Además de tener la función de armadura ante las batallas que se libran en los mercados —como la crisis financiera de 2008— funge como dinamizador de las economías al potenciar los proyectos de inversión con el aumento del emprendedurismo, impactando así en las variables macroeconómicas. Esta área del conocimiento ha adquirido importancia y popularidad a nivel internacional a raíz de las crisis económicas de los últimos años, sin embargo, aún existen, entre otras, brechas sociodemográficas, culturales, económicas, que no permiten el acceso a estas enseñanzas, excluyendo parte de la población del proceso del bienestar económico. Para ejemplificar esta desigualdad, en los capítulos se plasma un panorama internacional de la educación financiera, considerando las implicaciones y retos que han tenido las estrategias nacionales de educación financiera a nivel mundial

    Nutrición en Salud Pública

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    Este libro es fruto de una revisión y actualización ampliadas de los manuales docentes de «Nutrición en Salud Pública» y «La alimentación y el consumidor», editados en 2007 y 2013 respectivamente por la Escuela Nacional de Sanidad del Instituto de Salud Carlos III.La salud pública es el arte y la ciencia de prevenir la enfermedad, prolongar la vida y promover la salud a través de los esfuerzos organizados de la sociedad. La nutrición es la ciencia que estudia la forma en que el organismo utiliza la energía de los alimentos para mantenerse y crecer, mediante el análisis de los procesos por los cuales ingiere, digiere, absorbe, transporta, utiliza y extrae los nutrientes esenciales para la vida, y su interacción con la salud y la enfermedad. Por tanto, la nutrición en salud pública (public health nutrition) es la ciencia que estudia la relación entre dieta y salud y sienta las bases para el diseño, ejecución y evaluación de intervenciones nutricionales a nivel comunitario y poblacional con el objeto de mejorar el estado de salud de las poblaciones. La pandemia de obesidad, una enfermedad estrechamente relacionada con la nutrición, es uno de ejemplos paradigmáticos del carácter multidisciplinar e intersectorial de la salud pública. Hace décadas, la obesidad era considerada una enfermedad endocrina, de tipo glandular, dentro del dominio biomédico del especialista en endocrinología. Después se pasó a considerar algunos factores personales de riesgo, como los hábitos alimentarios y de actividad física, entrando en el dominio de la medicina preventiva, que centra sus esfuerzos en los factores biomédicos individuales, como la ingesta de calorías o el sedentarismo, y del entorno familiar. La salud pública va más allá, considerando factores ambientales, sociales y culturales que afectan a las preferencias alimentarias y los hábitos de vida, como los sistemas de producción de alimentos y fijación del precio de los mismos, el uso de subsidios y tasas, la publicidad alimentaria, el nivel socioeconómico de las familias, el diseño urbanístico (cantidad de espacios verdes, parques, carriles bici) o los sistemas de transporte urbano, entre otros muchos. El abordaje de elementos tan variados requiere del concurso de especialistas en múltiples disciplinas: profesionales sanitarios, abogados, economistas, periodistas, urbanistas, sociólogos, etc. Aunque ningún individuo puede ser experto en todas las especialidades relacionadas con la salud pública, el profesional bien formado debe conocer el rol de cada una de esas disciplinas en la formulación de una intervención de salud pública, estar familiarizado con el lenguaje y los postulados básicos de dichas disciplinas, y haber practicado la implementación de intervenciones a cargo de equipos multidisciplinarios

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Global economic burden of unmet surgical need for appendicitis

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    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
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