1,340 research outputs found

    Quantum gravitational corrections to black hole geometries

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    We calculate perturbative quantum gravity corrections to eternal two-dimensional black holes. We estimate the leading corrections to the AdS_2 black hole entropy and determine the quantum modification of N-dimensional Schwarzschild spacetime.Comment: 15 pages, 6 figures. Revised version: Introduction and conclusion expanded, section II reshaped, references added. Accepted for publication in Phys. Rev.

    Potts model on recursive lattices: some new exact results

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    We compute the partition function of the Potts model with arbitrary values of qq and temperature on some strip lattices. We consider strips of width Ly=2L_y=2, for three different lattices: square, diced and `shortest-path' (to be defined in the text). We also get the exact solution for strips of the Kagome lattice for widths Ly=2,3,4,5L_y=2,3,4,5. As further examples we consider two lattices with different type of regular symmetry: a strip with alternating layers of width Ly=3L_y=3 and Ly=m+2L_y=m+2, and a strip with variable width. Finally we make some remarks on the Fisher zeros for the Kagome lattice and their large q-limit.Comment: 17 pages, 19 figures. v2 typos corrected, title changed and references, acknowledgements and two further original examples added. v3 one further example added. v4 final versio

    Experiencias interdisciplinarias en alimentación y daños a la salud en las fronteras sur y norte de México

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    Los problemas de salud y alimentación en diferentes contextos como las fronteras sur y norte de México exige de trabajo interdisciplinar, con lenguajes y bases comunes para los grupos académicos. El objetivo de esta ponencia es reflexionar sobre la experiencia del grupo Seminario de “Alimentación y Daños a la Salud” (ADAS), el cual busca consolidar una propuesta de colaboración interinstitucional para el abordaje interdisciplinario de los problemas de salud relacionados con la alimentación y vulnerabilidad social en la frontera sur y norte de México.Facultad de Humanidades y Ciencias de la Educació

    Illness perceptions of COVID-19 in Europe: Predictors, impacts and temporal evolution

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    Objective: Illness perceptions (IP) are important predictors of emotional and behavioral responses in many diseases. The current study aims to investigate the COVID-19-related IP throughout Europe. The specific goals are to understand the temporal development, identify predictors (within demographics and contact with COVID-19) and examine the impacts of IP on perceived stress and preventive behaviors. Methods: This was a time-series-cross-section study of 7, 032 participants from 16 European countries using multilevel modeling from April to June 2020. IP were measured with the Brief Illness Perception Questionnaire. Temporal patterns were observed considering the date of participation and the date recoded to account the epidemiological evolution of each country. The outcomes considered were perceived stress and COVID-19 preventive behaviors. Results: There were significant trends, over time, for several IP, suggesting a small decrease in negativity in the perception of COVID-19 in the community. Age, gender, and education level related to some, but not all, IP. Considering the self-regulation model, perceptions consistently predicted general stress and were less consistently related to preventive behaviors. Country showed no effect in the predictive model, suggesting that national differences may have little relevance for IP, in this context. Conclusion: The present study provides a comprehensive picture of COVID-19 IP in Europe in an early stage of the pandemic. The results shed light on the process of IP formation with implications for health-related outcomes and their evolution. © Copyright © 2021 Dias Neto, Nunes da Silva, Roberto, Lubenko, Constantinou, Nicolaou, Lamnisos, Papacostas, Höfer, Presti, Squatrito, Vasiliou, McHugh, Monestès, Baban, Alvarez-Galvez, Paez-Blarrina, Montesinos, Valdivia-Salas, Ori, Lappalainen, Kleszcz, Gloster, Karekla and Kassianos

    Experiencias interdisciplinarias en alimentación y daños a la salud en las fronteras sur y norte de México

    Get PDF
    Los problemas de salud y alimentación en diferentes contextos como las fronteras sur y norte de México exige de trabajo interdisciplinar, con lenguajes y bases comunes para los grupos académicos. El objetivo de esta ponencia es reflexionar sobre la experiencia del grupo Seminario de “Alimentación y Daños a la Salud” (ADAS), el cual busca consolidar una propuesta de colaboración interinstitucional para el abordaje interdisciplinario de los problemas de salud relacionados con la alimentación y vulnerabilidad social en la frontera sur y norte de México.Facultad de Humanidades y Ciencias de la Educació

    A western route of prehistoric human migration from Africa into the Iberian Peninsula

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    Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar

    Mental Health Status of Healthcare Workers During the COVID-19 Outbreak An International Study

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    Background: The COVID-19 pandemic is a massive health crisis that has exerted enormous physical and psychological pressure. Mental healthcare for healthcare workers (HCWs) should receive serious consideration. This study served to determine the mental-health outcomes of 1,556 HCWs from 45 countries who participated in the COVID-19 IMPACT project, and to examine the predictors of the outcomes during the first pandemic wave. Methods: Outcomes assessed were self-reported perceived stress, depression symptom, and sleep changes. The predictors examined included sociodemographic factors and perceived social support. Results: The results demonstrated that half of the HCWs had moderate levels of perceived stress and symptoms of depression. Half of the HCWs (n = 800, 51.4%) had similar sleeping patterns since the pandemic started, and one in four slept more or slept less. HCWs reported less perceived stress and depression symptoms and higher levels of perceived social support than the general population who participated in the same project. Predictors associated with higher perceived stress and symptoms of depression among HCWs included female sex, not having children, living with parents, lower educational level, and lower social support. Discussion: The need for establishing ways to mitigate mental-health risks and adjusting psychological interventions and support for HCWs seems to be significant as the pandemic continues
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