201 research outputs found

    Magnetism of NaFePO4 and related polyanionic compounds

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    Magnetic properties of maricite (m) and triphlyte (t) polymorphs of NaFePO4 are investigated by combining ab initio density functional theory with a model Hamiltonian approach, where a realistic Hubbard-type model for magnetic Fe 3d states in NaFePO4 is constructed entirely from first-principles calculations. For these purposes, we perform a comparative study based on the pseudopotential and linear muffin-tin orbital methods while tackling the problem of parasitic non-sphericity of the exchange-correlation potential. Upon calculating the model parameters, magnetic properties are studied by applying the mean-field Hartree-Fock approximation and the theory of superexchange interactions to extract the corresponding interatomic exchange parameters. Despite some differences, the two methods provide a consistent description of the magnetic properties of NaFePO4. On the one hand, our calculations reproduce the correct magnetic ordering for t-NaFePO4 allowing for magnetoelectric effect, and the theoretical values of Néel and Curie-Weiss temperatures are in fair agreement with reported experimental data. Furthermore, we investigate the effect of chemical pressure on magnetic properties by substituting Na with Li and, in turn, we explain how a noncollinear magnetic alignment induced by an external magnetic field leads to magnetoelectric effect in NaFePO4 and other transition-metal phosphates. However, the origin of a magnetic superstructure with q = (1/2, 0, 1/2) observed experimentally in m-NaFePO4 remains puzzling. Instead, we predict that competing exchange interactions can lead to the formation of magnetic superstructures along the shortest orthorhombic c axis of m-NaFePO4, similar to multiferroic manganites. © 2018 the Owner Societies.Oier Arcelus and Javier Carrasco acknowledge the financial support of the Ministerio de Economía y Competitividad of Spain through the project ENE2016-81020-R. The SGI/IZO-SGIker UPV/EHU (Arina cluster), the i2BASQUE academic network, and the Barcelona Supercomputer Center are acknowledged for computational resources. Oier Arcelus acknowledges support by the Basque Government through a PhD grant (Reference No. PRE-2016-1-0044)

    European Society for Sexual Medicine position statement 'Assessment and hormonal management in adolescent and adult trans people, with attention for sexual function and satisfaction'

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    Background: There is a general lack of recommendations for and basic information tailored at sexologists and other health-care professionals for when they encounter trans people in their practice. Aim: We present to clinicians an up-to-date overview of clinical consensus statements on trans health care with attention for sexual function and satisfaction. Methods: The task force consisted of 7 clinicians experienced in trans health care, selected among European Society for Sexual Medicine (ESSM) scientific committee. The consensus was guided by clinical experience and a review of the available literature and by interactive discussions on trans health, with attention for sexual function and satisfaction where available. Outcomes: The foci of the study are assessment and hormonal aspects of trans health care. Results: As the available literature for direct recommendations was limited, most of the literature was used as background or indirect evidence. Clinical consensus statements were developed based on clinical experiences and the available literature. With the multiple barriers to care that many trans people experience, basic care principles still need to be stressed. We recommend that health-care professionals (HCPs) working with trans people recognize the diversity of genders, including male, female, and nonbinary individuals. In addition, HCPs assessing gender diverse children and adolescents should take a developmental approach that acknowledges the difference between prepubescent gender diverse children and pubescent gender diverse adolescents and trans adults. Furthermore, trans people seeking gender-affirming medical interventions should be assessed by HCPs with expertise in trans health care and gender-affirming psychological practice. If masculinization is desired, testosterone therapy with monitoring of serum sex steroid levels and signs of virilization is recommended. Similarly, if feminization is desired, we recommend estrogens and/or antiandrogen therapy with monitoring of serum sex steroid levels and signs of feminization. HCPs should be aware of the influence of hormonal therapy on sexual functioning and satisfaction. We recommend HCPs be aware of potential sexual problems during all surgical phases of treatment. Clinical Implications: This is an up-to-date ESSM position statement. Strengths & Limitations: These statements are based on the data that are currently available; however, it is vital to recognize that this is a rapidly changing field and that the literature, particularly in the field of sexual functioning and satisfaction, is limited. Conclusion: This ESSM position statement provides relevant information and references to existing clinical guidelines with the aim of informing relevant HCPs on best practices when working with transgender people

    Transgender and anxiety: a comparative study between transgender people and the general population

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    Background: Anxiety disorders pose serious public health problems. The data available on anxiety disorders in the transgender population is limited by the small numbers, the lack of a matched controlled population and the selection of a nonhomogenous group of transgender people. Aims: The aims of the study were (1) to determine anxiety symptomatology (based on the HADS) in a nontreated transgender population and to compare it to a general population sample matched by age and gender; (2) to investigate the predictive role of specific variables, including experienced gender, self-esteem, victimization, social support, interpersonal functioning, and cross-sex hormone use regarding levels of anxiety symptomatology; and (3) to investigate differences in anxiety symptomatology between transgender people on cross-sex hormone treatment and not on hormone treatment. Methods: A total of 913 individuals who self-identified as transgender attending a transgender health service during a 3-year period agreed to participate. For the first aim of the study, 592 transgender people not on treatment were matched by age and gender, with 3,816 people from the general population. For the second and third aim, the whole transgender population was included. Measurements: Sociodemographic variables and measures of depression and anxiety (HADS), self-esteem (RSE), victimization (ETS), social support (MSPSS), and interpersonal functioning (IIP-32). Results: Compared with the general population transgender people had a nearly threefold increased risk of probable anxiety disorder (all p < .05). Low self-esteem and interpersonal functioning were found to be significant predictors of anxiety symptoms. Trans women on treatment with cross-sex hormones were found to have lower levels of anxiety disorder symptomatology. Conclusions: Transgender people (particularly trans males) have higher levels of anxiety symptoms suggestive of possible anxiety disorders compared to the general population. The findings that self-esteem, interpersonal functioning, and hormone treatment are associated with lower levels of anxiety symptoms indicate the need for clinical interventions targeting self-esteem and interpersonal difficulties and highlight the importance of quick access to transgender health services

    Methylation QTLs in the developing brain and their enrichment in schizophrenia risk loci

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    We characterized DNA methylation quantitative trait loci (mQTLs) in a large collection (n = 166) of human fetal brain samples spanning 56-166 d post-conception, identifying >16,000 fetal brain mQTLs. Fetal brain mQTLs were primarily cis-acting, enriched in regulatory chromatin domains and transcription factor binding sites, and showed substantial overlap with genetic variants that were also associated with gene expression in the brain. Using tissue from three distinct regions of the adult brain (prefrontal cortex, striatum and cerebellum), we found that most fetal brain mQTLs were developmentally stable, although a subset was characterized by fetal-specific effects. Fetal brain mQTLs were enriched amongst risk loci identified in a recent large-scale genome-wide association study (GWAS) of schizophrenia, a severe psychiatric disorder with a hypothesized neurodevelopmental component. Finally, we found that mQTLs can be used to refine GWAS loci through the identification of discrete sites of variable fetal brain methylation associated with schizophrenia risk variants

    The macroeconomic effects of Government asset purchases: evidence from postwar US housing credit policy

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    We document the portfolio activity of federal housing agencies and provide evidence on its impact on mortgage markets and the economy. Through a narrative analysis, we identify historical policy changes leading to expansions or contractions in agency mortgage holdings. Based on those regulatory events that we classify as unrelated to short-run cyclical or credit market shocks, we find that an increase in mortgage purchases by the agencies boosts mortgage lending and lowers mortgage rates. Agency purchases influence prices in other asset markets and stimulate residential investment. Using information in GSE stock prices to construct an alternative instrument for agency purchasing activity yields very similar results as our benchmark narrative identification approach

    Patterns of Cis Regulatory Variation in Diverse Human Populations

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    The genetic basis of gene expression variation has long been studied with the aim to understand the landscape of regulatory variants, but also more recently to assist in the interpretation and elucidation of disease signals. To date, many studies have looked in specific tissues and population-based samples, but there has been limited assessment of the degree of inter-population variability in regulatory variation. We analyzed genome-wide gene expression in lymphoblastoid cell lines from a total of 726 individuals from 8 global populations from the HapMap3 project and correlated gene expression levels with HapMap3 SNPs located in cis to the genes. We describe the influence of ancestry on gene expression levels within and between these diverse human populations and uncover a non-negligible impact on global patterns of gene expression. We further dissect the specific functional pathways differentiated between populations. We also identify 5,691 expression quantitative trait loci (eQTLs) after controlling for both non-genetic factors and population admixture and observe that half of the cis-eQTLs are replicated in one or more of the populations. We highlight patterns of eQTL-sharing between populations, which are partially determined by population genetic relatedness, and discover significant sharing of eQTL effects between Asians, European-admixed, and African subpopulations. Specifically, we observe that both the effect size and the direction of effect for eQTLs are highly conserved across populations. We observe an increasing proximity of eQTLs toward the transcription start site as sharing of eQTLs among populations increases, highlighting that variants close to TSS have stronger effects and therefore are more likely to be detected across a wider panel of populations. Together these results offer a unique picture and resource of the degree of differentiation among human populations in functional regulatory variation and provide an estimate for the transferability of complex trait variants across populations

    Rate-Dependent Nucleation and Growth of NaO2 in Na-O2 Batteries

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    Understanding the oxygen reduction reaction kinetics in the presence of Na ions and the formation mechanism of discharge product(s) is key to enhancing Na–O2 battery performance. Here we show NaO2 as the only discharge product from Na–O2 cells with carbon nanotubes in 1,2-dimethoxyethane from X-ray diffraction and Raman spectroscopy. Sodium peroxide dihydrate was not detected in the discharged electrode with up to 6000 ppm of H2O added to the electrolyte, but it was detected with ambient air exposure. In addition, we show that the sizes and distributions of NaO2 can be highly dependent on the discharge rate, and we discuss the formation mechanisms responsible for this rate dependence. Micron-sized (∼500 nm) and nanometer-scale (∼50 nm) cubes were found on the top and bottom of a carbon nanotube (CNT) carpet electrode and along CNT sidewalls at 10 mA/g, while only micron-scale cubes (∼2 μm) were found on the top and bottom of the CNT carpet at 1000 mA/g, respectively.Seventh Framework Programme (European Commission) (Marie Curie International Outgoing Fellowship, 2007-2013))National Science Foundation (U.S.) (MRSEC Program, award number DMR-0819762)Robert Bosch GmbH (Bosch Energy Research Network (BERN) Grant)China Clean Energy Research Center-Clean Vehicles Consortium (CERC-CVC) (award number DE-PI0000012)Skolkovo Institute of Science and Technology (Skoltech-MIT Center for Electochemical Energy Storage

    Genome-wide analysis of differential transcriptional and epigenetic variability across human immune cell types

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    Abstract Background A healthy immune system requires immune cells that adapt rapidly to environmental challenges. This phenotypic plasticity can be mediated by transcriptional and epigenetic variability. Results We apply a novel analytical approach to measure and compare transcriptional and epigenetic variability genome-wide across CD14+CD16− monocytes, CD66b+CD16+ neutrophils, and CD4+CD45RA+ naïve T cells from the same 125 healthy individuals. We discover substantially increased variability in neutrophils compared to monocytes and T cells. In neutrophils, genes with hypervariable expression are found to be implicated in key immune pathways and are associated with cellular properties and environmental exposure. We also observe increased sex-specific gene expression differences in neutrophils. Neutrophil-specific DNA methylation hypervariable sites are enriched at dynamic chromatin regions and active enhancers. Conclusions Our data highlight the importance of transcriptional and epigenetic variability for the key role of neutrophils as the first responders to inflammatory stimuli. We provide a resource to enable further functional studies into the plasticity of immune cells, which can be accessed from: http://blueprint-dev.bioinfo.cnio.es/WP10/hypervariability

    Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

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    Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person
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