5,096 research outputs found

    Images of the body: Lay and biomedical views of the reproductive system in Britain and Brazil

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    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents an anthropological study of ordinary people's views about the body in general and the reproductive system in particular, based on two case studies carried out in Britain and in Brazil. I discuss the meanings of lay and biomedical images of the body and identify the ways the researched groups reinterpret the biomedical view of the body anatomy and physiology. Through the analysis of ethnographic material on time, space and domestic organisation in four shantytown groups in Porto Alegre, Brazil and in three different groups in London, UK, I point out the dwelling peculiarities of the different groups and suggest there is a relationship between embodied experiences of time/space and knowledge of the reproductive system. These arguments lead to a more general phenomenologically theorised view of gendered and status-framed bodies, consequently situating this work in the interface of Medical Anthropology and a more general socio-cultural Anthropology.This study is funded by the CNPQ - Conselho Nacional de Desenvolvimento Cientifico e Tecnologico

    The transcription factor Foxo1 controls germinal center B cell proliferation in response to T cell help

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    Germinal center (GC) B cells cycle between two states, the light zone (LZ) and the dark zone (DZ), and in the latter they proliferate and hypermutate their immunoglobulin genes. How this functional transition takes place is still controversial. In this study, we demonstrate that ablation of Foxo1 after GC development led to the loss of the DZ GC B cells and disruption of the GC architecture, which is consistent with recent studies. Mechanistically, even upon provision of adequate T cell help, Foxo1-deficient GC B cells showed less proliferative expansion than controls. Moreover, we found that the transcription factor BATF was transiently induced in LZ GC B cells in a Foxo1-dependent manner and that deletion of BATF similarly led to GC disruption. Thus, our results are consistent with a model where the switch from the LZ to the DZ is triggered after receipt of T cell help, and suggest that Foxo1-mediated BATF up-regulation is at least partly involved in this switch

    New opportunities for photon storage and detection: an exploration of a high-efficiency optical quantum memory and the quantum capabilities of the human eye

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    The field of quantum information has grown in recent years, due to tremendous technological advancements toward quantum networking and quantum computation. Nevertheless, there is still a great need for creative research that explores possibilities for new capabilities. Particularly, we look towards quantum optics research to develop new ways of manipulating and detecting photons. Here, we discuss our efforts toward developing two separate quantum optics experiments that can provide great insight into the development of quantum devices. We begin by discussing our work to investigate the lower threshold of human vision and the eye's potential as a single-photon detector, using a custom-built single-photon source, and a novel two-alternative forced-choice experimental design. Our preliminary findings show promising data that support previous results found from a similar experiment using a somewhat different approach. We then discuss our second project, where we have developed a robust reconfigurable optical delay line quantum memory that compares favorably with competing methods. Our memory is capable of photon storage with an unprecedentedly high time-bandwidth product, high free-space transmission over the range of 10 \mus, and high fidelity. These attributes, plus the memory's capability for multi-mode storage, make this system a strong candidate for a critical component in the large-scale heterogeneous quantum networks we hope to see developed in the next ten years

    Ferromagnetic relaxation by magnon-induced currents

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    A theory for calculating spin wave relaxation times based on the magnon-electron interaction is developed. The theory incorporates a thin film geometry and is valid for a large range of magnon frequencies and wave vectors. For high conductivity metals such as permalloy, the wave vector dependent damping constant approaches values as high as 0.2, showing the large magnitude of the effect, and can dominate experimentally observed relaxation.Comment: 5 pages, 4 figure

    Think coalitions in contemplrary Argentine

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    Este art铆culo analiza el fracaso de los procesos de conversi贸n de las coaliciones electorales en coaliciones de gobierno, y la dif铆cil institucionalizaci贸n de las coaliciones en Argentina, desde una perspectiva de estudio interesada en destacar la articulaci贸n entre factores hist贸ricos de larga duraci贸n y transformaciones pol铆ticas recientes. Desde este 谩ngulo de preocupaciones, se sostiene que las coaliciones fueron m谩s un instrumento de construcci贸n de hegemon铆a en clave de gobierno de 鈥渦nidad nacional鈥 que un sistema de pactos inspirado en el principio del poder compartido.This article analyzes the failure of the processes of conversion of the electoral coalitions in coalitions of government, and the difficult institutionalization of the coalitions in Argentina, from a perspective of study interested in emphasizing the joint between historical factors of long duration and political recent transformations. From this angle of worries, is held that the coalitions were more an instrument of construction of hegemony in key of government of 鈥渘ational unit鈥 that a system of agreements inspired by the beginning of the shared power.Fil: Tcach, Cesar Eduardo. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - C贸rdoba. Centro de Investigaciones y Estudios Sobre Cultura y Sociedad. Universidad Nacional de C贸rdoba. Centro de Investigaciones y Estudios Sobre Cultura y Sociedad; Argentin

    Using genotype abundance to improve phylogenetic inference

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    Modern biological techniques enable very dense genetic sampling of unfolding evolutionary histories, and thus frequently sample some genotypes multiple times. This motivates strategies to incorporate genotype abundance information in phylogenetic inference. In this paper, we synthesize a stochastic process model with standard sequence-based phylogenetic optimality, and show that tree estimation is substantially improved by doing so. Our method is validated with extensive simulations and an experimental single-cell lineage tracing study of germinal center B cell receptor affinity maturation

    Exchange coupled perpendicular media

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    The potential of exchange spring bilayers and graded media is reviewed. An analytical model for the optimization of graded media gives an optimal value of the magnetic polarization of Js = 0.8 T. The optimum design allows for thermally stable grains with grain diameters in the order of 3.3 nm, which supports ultra high density up to 5 to 10 Tbit per inch2. The switching field distribution is significantly reduced in bilayer media and graded media compared to single phase media. For the graded media the switching field distribution is reduced by about a factor of two. For bilayer media the minimum switching field distribution is obtained for soft layer anisotropies about one fifth of the hard layer anisotropy. The influence of precessional switching on the reversal time and the reversal field is investigated in detail for magnetic bilayers. Exchange spring bilayers can be reversed with field pulses of 20 ps.Comment: submitted to JMMM, 'Current Perspectives; Perpendicular recording

    Do muscle strength imbalances and low flexibility levels lead to low back pain? A brief review

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    Chronic low back pain (CLBP) has been related to hips, trunk and spine strength imbalances and/or low flexibility levels. However, it is not clear if the assessment and normalization of these variables are effective for prevention of low back pain (LBP) episodes and rehabilitation of patients with CLBP. This brief review explored studies that have associated hip, trunk and spine strength imbalances and/or low flexibility levels to LBP episodes or CLBP condition. Fourteen studies were selected by accessing PubMed and Google Scholar databases. Collectively, the selected studies demonstrate that trunk eccentric/concentric and flexion/extension strength imbalances may be associated with CLBP or LBP episodes. However, the literature fails to demonstrate any clear relationship between hip strength imbalances or low levels of spine flexibility with CLBP or LBP episodes. In addition, there is no direct evidence to support the idea that the normalization of these variables due to resistance and flexibility training leads to pain reduction and functionality improvements in subjects with CLBP. Although further investigation is needed, the lack of a clear direct association between hip strength imbalances or spine low flexibility levels to CLBP or LBP episodes may demonstrate that these variables may have very low effect within the complexity of these conditions

    Data Resource Profile: Countdown to 2015: Maternal, Newborn and Child Survival

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    The Countdown to 2015 country profiles present, in one place, comprehensive evidence to enable an assessment of a country's progress in improving reproductive, maternal, newborn and child health. Profiles are available for each of the 75 countries that together account for more than 95% of all maternal and child deaths. The two-page profiles are updated approximately every 2 years with new data and analyses. Profile data include demographics, mortality, nutritional status, coverage of evidence-based interventions, within-countries inequalities in coverage, measures of health system functionality, supportive policies and financing indicators. The main sources of data for the coverage, nutritional status and equity indicators are the US Agency for Internal Development (USAID)-supported demographic and health surveys and the United Nations Children's Fund (UNICEF)-supported multiple indicator cluster surveys. Data on coverage are first summarized and checked for quality by UNICEF, and data on equity in intervention coverage are summarized and checked by the Federal University of Pelotas. The mortality estimates are developed by the Inter-agency Group for Child Mortality Estimation and the Maternal Mortality Estimation Inter-Agency Group. The financing data are abstracted from datasets maintained by the Organization for Economic Co-operation and Development Assistance Committee, and the policies and health systems data are derived from a special compilation prepared by the World Health Organization. Associated country profiles include equity-specific profiles and one-page profiles prepared annually that report on the 11 indicators selected by the Commission on Information and Accountability for Women's and Children's Healt
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