Sexually transmitted infection as a risk factor for homosexual HIV transmission: a systematic review of epidemiological studies

Existing reviews suggest some sexually transmitted infections (STIs) are risk factors in heterosexual HIV transmission. This may not be so in homosexual HIV transmission, about which reviews make no specific conclusions. This paper reviews published studies which report on the relative risk of STIs in HIV seroconversion in homosexually-active men in order to examine this matter. Papers obtained via various searches were judged adequate if they were prospective cohort or cohort-nested case-control studies; used HIV seroconversion as the outcome; assessed STI exposure objectively; and controlled for potential confounding from age and sexual behaviour. Sixteen papers were obtained, of these 3 were judged adequate. Adequate papers reported little association. Inadequate papers were more likely to report association. Evidence from adequate studies does not suggest STIs are risk factors in homosexual HIV transmission. Some caution is needed in interpreting the results because of the paucity of adequate studies

Are randomised controlled trials positivist? Reviewing the social science and philosophy literature to assess positivist tendencies of trials of social interventions in public health and health services

Background: We have previously proposed that trials of social interventions can be done within a ‘realist’ research paradigm. Critics have countered that such trials are irredeemably positivist and asked us to explain our philosophical position. Methods: We set out to explore what is meant by positivism and whether trials adhere to its tenets (of necessity or in practice) via a narrative literature review of social science and philosophical discussions of positivism, and of the trials literature and three case studies of trials. Results: The philosophical literature described positivism as asserting: 1) the epistemic primacy of sensory information; 2) the requirement that theoretical terms equate with empirical terms; 3) the aim of developing universal laws; and 4) the unity of method between natural and social sciences. Regarding 1), it seems that rather than embodying the epistemic primacy of sensory data, RCTs of social interventions in health embrace an anti-positivist approach aiming to test hypotheses derived deductively from prior theory. Considering 2), while some RCTs of social interventions appear to limit theorization to concepts with empirical analogues, others examine interventions underpinned by theories engaging with mechanisms and contextual contingencies not all of which can be measured. Regarding 3), while some trialists and reviewers in the health field do limit their role to estimating statistical trends as a mechanistic form of generalization, this is not an inevitable feature of RCT-based research. Trials of social interventions can instead aim to generalize at the level of theory which specifies how mechanisms are contingent on context. In terms of 4), while RCTs are used to examine biomedical as well as social interventions in health, RCTs of social interventions are often distinctive in using qualitative analyses of data on participant accounts to examine questions of meaning and agency not pursued in the natural sciences. Conclusion: We conclude that the most appropriate paradigm for RCTs of social interventions is realism not positivism

Albert Gleizes y las leyes de la pintura: un retorno a la Edad Media

En el context d'aquella tendencia general anomenada ale rappel a I'ordre, Albert Gleizes publica I'any 1923 un dels seus textos de teoria mes importants. Allí, hi mirava de definir el que el1 entenia per les Ileis de la pintura. El treball era el resultat d'un procés d'especulació molt llarg dominat pel un punt de vista anti-elitista i anti-individualista, el qual afectava a I'artista i a la seva activitat productiva. Segons Gleizes, I'art clAssic i el post-Renaixentista eren conseqübncia d'una cultura individualista mancada d'espiritualitat. Cautor, en canvi, admirava allo que hi havia de proposit col.lectiu en I'art mural de I'Edat Mitjana. D'aquest darrer, Gleizes creia que havia jugat un paper fonamental en la composició espacial d'uns ritmes abstractes que al seu entendre reflectien els ritmes sensibles de I'Univers.In 1923, in the context of the general tendecy known as le rappel a I'ordre, Albert Gleizes first published one of his most important theoretical writings in an attempt to define the laws of painting as he understood them. This was, at last, the result of a long speculative process dominated by his anti-élitist, anti-individualist view of the artist and of the activity of making art. For Gleizes, classical and post-Renaissance art was a consequence of a nonspiritual,individualistic culture; instead, he admired the collective purpose of the mural art of the Middle Ages which, he believed, had given a fundamentally compositional role to abstract rhythms that echoed the sensed rhythms of the universe

Esquemas sistema fiscal español

La tarea del profesor es ofrecer al estudiante las claves para que avance en el análisis de la materia, despejando sus dudas, respondiendo a sus cuestiones. La amplitud y complejidad del Sistema Fiscal Español, unidas al necesario ejercicio de descifrar los tributos, me han sugerido la conveniencia de ayudar al estudiante a reconducir su tarea a través de unos esquemas elementales que le sirvan para su personalizada asimilación del Régimen Fiscal. Cualquiera que sea la perspectiva con que el lector pueda acudir a esta nota técnica, sirviéndo de guía, solicita una lectura activa de los textos normativos, con el uso de la bibliografía, y manuales de la Agencia Tributaria, sin la cual los esquemas no pasarán de ser un mero esqueleto de los impuestos. Esta modesta pretensión docente es la que ha motivado la nota técnica, a la vez de que no pretende enseñar, sino instruir al estudiante o lector interesado en el sistema fiscal, y que he estructurado en cinco partes: La primera parte está dedicada a los esquemas de dogmática tributaria que se corresponden con la introducción de la Ley General Tributaria. Para continuar con el IRPF, el IS, ITP AJD e IVA

Spin precession and spin Hall effect in monolayer graphene/Pt nanostructures

Spin Hall effects have surged as promising phenomena for spin logics operations without ferromagnets. However, the magnitude of the detected electric signals at room temperature in metallic systems has been so far underwhelming. Here, we demonstrate a two-order of magnitude enhancement of the signal in monolayer graphene/Pt devices when compared to their fully metallic counterparts. The enhancement stems in part from efficient spin injection and the large resistivity of graphene but we also observe 100% spin absorption in Pt and find an unusually large effective spin Hall angle of up to 0.15. The large spin-to-charge conversion allows us to characterise spin precession in graphene under the presence of a magnetic field. Furthermore, by developing an analytical model based on the 1D diffusive spin-transport, we demonstrate that the effective spin-relaxation time in graphene can be accurately determined using the (inverse) spin Hall effect as a means of detection. This is a necessary step to gather full understanding of the consequences of spin absorption in spin Hall devices, which is known to suppress effective spin lifetimes in both metallic and graphene systems.Comment: 14 pages, 6 figures. Accepted in 2D Materials. https://doi.org/10.1088/2053-1583/aa882

Los intermediarios fiscales y su impacto en la concienciación cívico-tributaria: gestión y recaudación tributaria

El problema creciente de falta de recaudación suficiente ante el endeudamiento de las Administraciones Públicas, es el reflejo de una defectuosa concepción del modelo de desarrollo y también del procedimiento de gestión y recaudación tributaria llevados a cabo. Es por ello que en el presente trabajo ofrecemos la solución idónea

Tax Policy Challenges in the 21st Century: Smart Tax Policies. Trying to change the world progressively, as the global phenomenon "Pokémon Go".

The article discusses fundamentals aspects of taxes and training role of the Government, the Prime Minister in the 21st century. Firstly, the text revises some of the main changes currently taking place in the new century. Secondly, the study points out some aspects to consider in the development of Tax process, and Smart Tax Policies