190 research outputs found

    Primordial Black Holes: sirens of the early Universe

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    Primordial Black Holes (PBHs) are, typically light, black holes which can form in the early Universe. There are a number of formation mechanisms, including the collapse of large density perturbations, cosmic string loops and bubble collisions. The number of PBHs formed is tightly constrained by the consequences of their evaporation and their lensing and dynamical effects. Therefore PBHs are a powerful probe of the physics of the early Universe, in particular models of inflation. They are also a potential cold dark matter candidate.Comment: 21 pages. To be published in "Quantum Aspects of Black Holes", ed. X. Calmet (Springer, 2014

    Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters

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    Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the formation of massive star clusters, which includes several episodes of star formation. While this provides an explanation for several features of globular clusters, including the second parameter problem, it also opens new perspectives about the relation between globular clusters and the halo of our Galaxy, and by extension of all populations with a high specific frequency of globular clusters, such as, e.g., giant elliptical galaxies. We review progress in this area, focusing on the most recent studies. Several points remain to be properly understood, in particular those concerning the nature of the polluters producing the abundance pattern in the clusters and the typical timescale, the range of cluster masses where this phenomenon is active, and the relation between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review

    Variant -and individual dependent nature of persistent Anaplasma phagocytophilum infection

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    <p>Abstract</p> <p>Background</p> <p><it>Anaplasma phagocytophilum </it>is the causative agent of tick-borne fever in ruminants and human granulocytotropic anaplasmosis (HGA). The bacterium is able to survive for several months in immune-competent sheep by modifying important cellular and humoral defence mechanisms. Little is known about how different strains of <it>A. phagocytophilum </it>propagate in their natural hosts during persistent infection.</p> <p>Methods</p> <p>Two groups of five lambs were infected with each of two <it>16S </it>rRNA gene variants of <it>A. phagocytophilum</it>, i.e. <it>16S </it>variant 1 which is identical to GenBank no <ext-link ext-link-id="M73220" ext-link-type="gen">M73220</ext-link> and <it>16S </it>variant 2 which is identical to GenBank no <ext-link ext-link-id="AF336220" ext-link-type="gen">AF336220</ext-link>, respectively. The lambs were infected intravenously and followed by blood sampling for six months. <it>A. phagocytophilum </it>infection in the peripheral blood was detected by absolute quantitative real-time PCR.</p> <p>Results</p> <p>Both <it>16S </it>rRNA gene variants of <it>A. phagocytophilum </it>established persistent infection for at least six months and showed cyclic bacteraemias, but variant 1 introduced more frequent periods of bacteraemia and higher number of organisms than <it>16S </it>rRNA gene variant 2 in the peripheral blood.</p> <p>Conclusion</p> <p>Organisms were available from blood more or less constantly during the persistent infection and there were individual differences in cyclic activity of <it>A. phagocytophilum </it>in the infected animals. Two <it>16S </it>rRNA gene variants of <it>A. phagocytophilum </it>show differences in cyclic activity during persistent infection in lambs.</p

    Revisión de la literatura integradora acerca de intervenciones de la enfermería volcadas hacia el incremento del autocuidado entre pacientes con insuficiencia cardiaca

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    Objective: to analyze and summarize knowledge concerning critical components of interventions that have been proposed and implemented by nurses with the aim of optimizing self-care by heart failure patients.Methods: PubMed and CINAHL were the electronic databases used to search full peer-reviewed papers, presenting descriptions of nursing interventions directed to patients or to patients and their families and designed to optimize self-care. Forty-two studies were included in the final sample (n=4,799 patients).Results: this review pointed to a variety and complexity of nursing interventions. As self-care encompasses several behaviors, interventions targeted an average of 3.6 behaviors. Educational/counselling activities were combined or not with cognitive behavioral strategies, but only about half of the studies used a theoretical background to guide interventions. Clinical assessment and management were frequently associated with self-care interventions, which varied in number of sessions (1 to 30); length of follow-up (2 weeks to 12 months) and endpoints.Conclusions: these findings may be useful to inform nurses about further research in self-care interventions in order to propose the comparison of different modalities of intervention, the use of theoretical background and the establishment of endpoints to evaluate their effectiveness.Objetivo:analisar e sintetizar o conchecimento relacionado aos componentes críticos das intervençoes que têm, sido propostas e implementadas por enfermeiros(as) com objetivo de optimizar o auto-cuidado de pacientes portadores de insuficiência cardíaca.Método:PubMed e CINAHL foram as bases de dados electrônicas utilizadas para investigar artigos revisados por pares (peer review), apresentando as descrições das intervenções dirigidas ao paciente ou ao paciente e sua familia, visando melhorar o auto-cuidado. Foram incluídos 42 estudos na amostra final (n=4799 pacientes).Resultados:esta revisão apontou variedade e complexidade das intervenções de enfermagem. Como o auto-cuidado envolve diferentes comportamentos, as intervenções visaram em média 3,6 comportamentos. As Atividades de educação e aconselhamento foram combinadas ou não com estratégias cognitivo-comportamentais, mas somente a metade dos estudos utilizaram suporte teórico para guiar as intervenções. A avaliação e o manejo clínico foram frequentemente associados às intervenções de auto-cuidado, as quais variam em número de sessões (1 a 30), duração do seguimento (2 semanas a 12 meses) e desfechos.Conclusão:estes resultados podem ser úteis para guiar os enfermeiros no que se refere à futuros estudos sobre intervenções de auto-cuidado, de maneira a propor a comparação de diferentes modalidades de intervenção, uso de suporte teórico e estabelecimento de desfechos para melhor avaliar sua eficácia.Objetivo:analizar y sintetizar el conocimiento relacionado a componentes críticos de intervenciones que han sido propuestas e implementadas por enfermeros(as) con el objetivo de optimizar el autocuidado entre pacientes con insuficiencia cardiaca.Método:PUBMED y CINAHL han sido las bases de datos electrónicas usadas para investigar artículos revisados por pares (peer review), presentando descripciones de intervenciones destinadas a perfeccionar el autocuidado dirigido al paciente o al paciente y a su familia. Se incluyeron 42 estudios en la muestra final (n=4799 pacientes).Resultados:esta revisión apuntó a una variedad y complejidad de intervenciones de enfermería. Como el autocuidado abarca varios comportamientos, las intervenciones tuvieron como blanco, en media, 3,6 comportamientos. Actividades de educación/consejería fueron combinadas o no con estrategias cognitivo-comportamentales, pero tan solo cerca de la mitad de los estudios tenían aporte teórico para guiar intervenciones. La gestión y la evaluación clínica fueron frecuentemente asociadas a intervenciones de autocuidado, las cuales oscilaron en número de sesiones (1 a 30), duración del seguimiento (2 semanas a 12 meses) y objetivos.Conclusiones:estos resultados pueden ser útiles para informar a las enfermeras acerca de nuevas investigaciones en intervenciones de autocuidado, de modo a proponer la comparación de distintas modalidades de intervención, el uso de un aporte teórico y el establecimiento de objetivos para evaluar su eficacia

    The management of patients with primary chronic anal fissure: a position paper

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    Anal fissure is one of the most common and painful proctologic diseases. Its treatment has long been discussed and several different therapeutic options have been proposed. In the last decades, the understanding of its pathophysiology has led to a progressive reduction of invasive and potentially invalidating treatments in favor of conservative treatment based on anal sphincter muscle relaxation. Despite some systematic reviews and an American position statement, there is ongoing debate about the best treatment for anal fissure. This review is aimed at identifying the best treatment option drawing on evidence-based medicine and on the expert advice of 6 colorectal surgeons with extensive experience in this field in order to produce an Italian position statement for anal fissures. While there is little chance of a cure with conservative behavioral therapy, medical treatment with calcium channel blockers, diltiazem and nifepidine or glyceryl trinitrate, had a considerable success rate ranging from 50 to 90%. Use of 0.4% glyceryl trinitrate in standardized fashion seems to have the best results despite a higher percentage of headache, while the use of botulinum toxin had inconsistent results. Nonresponding patients should undergo lateral internal sphincterotomy. The risk of incontinence after this procedure seems to have been overemphasized in the past. Only a carefully selected group of patients, without anal hypertonia, could benefit from anoplasty

    Tailored Print Communication and Telephone Motivational Interviewing Are Equally Successful in Improving Multiple Lifestyle Behaviors in a Randomized Controlled Trial

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    Background: Computer tailoring and motivational interviewing show promise in promoting lifestyle change, despite few head-to-head comparative studies. Purpose: Vitalum is a randomized controlled trial in which the efficacy of these methods was compared in changing physical activity and fruit and vegetable consumption in middle-aged Dutch adults. Methods: Participants (n?=?1,629) were recruited via 23 general practices and randomly received either four tailored print letters, four motivational telephone calls, two of each type of intervention, or no information. The primary outcomes were absolute change in self-reported physical activity and fruit and vegetable consumption. Results: All three intervention groups (i.e., the tailored letters, the motivational calls, and the combined version) were equally and significantly more effective than the control group in increasing physical activity (hours/day), intake of fruit (servings/day), and consumption of vegetables (grams/day) from baseline to the intermediate measurement (week 25), follow-up 1 (week 47) and 2 (week 73). Effect sizes (Cohen's d) ranged from 0.15 to 0.18. Participants rated the interventions positively; interviews were more positively evaluated than letters. Conclusions: Tailored print communication and telephone motivational interviewing or their combination are equally successful in changing multiple behaviors. © 2010 The Author(s)

    Globular cluster systems and galaxy formation

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    Globular clusters are compact, gravitationally bound systems of up to a million stars. The GCs in the Milky Way contain some of the oldest stars known, and provide important clues to the early formation and continuing evolution of our Galaxy. More generally, GCs are associated with galaxies of all types and masses, from low-mass dwarf galaxies to the most massive early-type galaxies which lie in the centres of massive galaxy clusters. GC systems show several properties which connect tightly with properties of their host galaxies. For example, the total mass of GCs in a system scales linearly with the dark matter halo mass of its host galaxy. Numerical simulations are at the point of being able to resolve globular cluster formation within a cosmological framework. Therefore, GCs link a range of scales, from the physics of star formation in turbulent gas clouds, to the large-scale properties of galaxies and their dark matter. In this Chapter we review some of the basic observational approaches for GC systems, some of their key observational properties, and describe how GCs provide important clues to the formation of their parent galaxies.Comment: 32 pages, 6 figures. Accepted for publication in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556

    Die Stoffwechselwirkungen der Schilddrüsenhormone

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