736 research outputs found

    On invariants of almost symplectic connections

    Get PDF
    We study the irreducible decomposition under Sp(2n, R) of the space of torsion tensors of almost symplectic connections. Then a description of all symplectic quadratic invariants of torsion-like tensors is given. When applied to a manifold M with an almost symplectic structure, these instruments give preliminary insight for finding a preferred linear almost symplectic connection on M . We rediscover Ph. Tondeur's Theorem on almost symplectic connections. Properties of torsion of the vectorial kind are deduced

    Why women do not ask for information on preconception health? A qualitative study.

    Get PDF
    BACKGROUND: Preconception care involves health promotion to reduce risk factors that might affect women and couples of childbearing age. The risk factors of adverse reproductive outcomes include recognized genetic diseases in the family or the individual, previous congenital diseases, miscarriage, prematurity, fetal growth restriction, infertility, chronic maternal diseases, lifestyle, and occupational or environmental factors. Effective preconception care involves a range of preventive, therapeutic and behavioural interventions. Although in Italy there are national preconception care recommendations concerning the general population, they are usually encouraged informally and only for single risk factors. At present there is increasing interest in offering a global intervention in this field. The aim of this study was to investigate attitudes and behaviours of Italian women of childbearing age and healthcare professionals regarding preconception health. METHODS: We conducted a qualitative study among women of childbearing age and healthcare professionals between February 2014 and February 2015. Five focus groups were held: 2 with non-pregnant women aged 22 to 44 years and 3 with healthcare professionals. Discussion topics included women's questions about preconception health, worries and barriers regarding preconception care interventions, attitudes and behaviours of women and healthcare professionals towards preconception health, women's information sources. In the analysis of the focus groups priority was given to what was said by the women, supplemented by information from the healthcare professionals' focus groups. RESULTS: Fourteen women of childbearing age (8 nulliparae and 6 multiparae) and 12 healthcare professionals (3 nurses, 4 midwives, 5 doctors) participated in the focus groups. The results indicate the presence of many barriers and a lack of awareness of preconception health relating to women, healthcare professionals and policies. Women's knowledge and attitudes towards primary preconception care information are described. The main reference source of information in this field for Italian women seems to be their obstetric-gynaecologist. CONCLUSIONS: The study indicates that several barriers influence preconception care in Italy. Moreover, a lack of awareness of preconception health and care among Italian women of childbearing age and healthcare professionals emerges. The findings might contribute to strategies for the implementation of preconception care guidelines

    Chiral Asymmetry and the Spectral Action

    Full text link
    We consider orthogonal connections with arbitrary torsion on compact Riemannian manifolds. For the induced Dirac operators, twisted Dirac operators and Dirac operators of Chamseddine-Connes type we compute the spectral action. In addition to the Einstein-Hilbert action and the bosonic part of the Standard Model Lagrangian we find the Holst term from Loop Quantum Gravity, a coupling of the Holst term to the scalar curvature and a prediction for the value of the Barbero-Immirzi parameter

    Why women do not ask for information on preconception health? A qualitative study.

    Get PDF
    BACKGROUND: Preconception care involves health promotion to reduce risk factors that might affect women and couples of childbearing age. The risk factors of adverse reproductive outcomes include recognized genetic diseases in the family or the individual, previous congenital diseases, miscarriage, prematurity, fetal growth restriction, infertility, chronic maternal diseases, lifestyle, and occupational or environmental factors. Effective preconception care involves a range of preventive, therapeutic and behavioural interventions. Although in Italy there are national preconception care recommendations concerning the general population, they are usually encouraged informally and only for single risk factors. At present there is increasing interest in offering a global intervention in this field. The aim of this study was to investigate attitudes and behaviours of Italian women of childbearing age and healthcare professionals regarding preconception health. METHODS: We conducted a qualitative study among women of childbearing age and healthcare professionals between February 2014 and February 2015. Five focus groups were held: 2 with non-pregnant women aged 22 to 44 years and 3 with healthcare professionals. Discussion topics included women's questions about preconception health, worries and barriers regarding preconception care interventions, attitudes and behaviours of women and healthcare professionals towards preconception health, women's information sources. In the analysis of the focus groups priority was given to what was said by the women, supplemented by information from the healthcare professionals' focus groups. RESULTS: Fourteen women of childbearing age (8 nulliparae and 6 multiparae) and 12 healthcare professionals (3 nurses, 4 midwives, 5 doctors) participated in the focus groups. The results indicate the presence of many barriers and a lack of awareness of preconception health relating to women, healthcare professionals and policies. Women's knowledge and attitudes towards primary preconception care information are described. The main reference source of information in this field for Italian women seems to be their obstetric-gynaecologist. CONCLUSIONS: The study indicates that several barriers influence preconception care in Italy. Moreover, a lack of awareness of preconception health and care among Italian women of childbearing age and healthcare professionals emerges. The findings might contribute to strategies for the implementation of preconception care guidelines

    Instantons and Killing spinors

    Get PDF
    We investigate instantons on manifolds with Killing spinors and their cones. Examples of manifolds with Killing spinors include nearly Kaehler 6-manifolds, nearly parallel G_2-manifolds in dimension 7, Sasaki-Einstein manifolds, and 3-Sasakian manifolds. We construct a connection on the tangent bundle over these manifolds which solves the instanton equation, and also show that the instanton equation implies the Yang-Mills equation, despite the presence of torsion. We then construct instantons on the cones over these manifolds, and lift them to solutions of heterotic supergravity. Amongst our solutions are new instantons on even-dimensional Euclidean spaces, as well as the well-known BPST, quaternionic and octonionic instantons.Comment: 40 pages, 2 figures v2: author email addresses and affiliations adde

    An automated workflow based on hip shape improves personalized risk prediction for hip osteoarthritis in the CHECK study

    Get PDF
    Objective: To design an automated workflow for hip radiographs focused on joint shape and tests its prognostic value for future hip osteoarthritis. Design: We used baseline and 8-year follow-up data from 1,002 participants of the CHECK-study. The primary outcome was definite radiographic hip osteoarthritis (rHOA) (Kellgren–Lawrence grade ≥2 or joint replacement) at 8-year follow-up. We designed a method to automatically segment the hip joint from radiographs. Subsequently, we applied machine learning algorithms (elastic net with automated parameter optimization) to provide the Shape-Score, a single value describing the risk for future rHOA based solely on joint shape. We built and internally validated prediction models using baseline demographics, physical examination, and radiologists scores and tested the added prognostic value of the Shape-Score using Area-Under-the-Curve (AUC). Missing data was imputed by multiple imputation by chained equations. Only hips with pain in the corresponding leg were included. Results: 84% were female, mean age was 56 (±5.1) years, mean BMI 26.3 (±4.2). Of 1,044 hips with pain at baseline and complete follow-up, 143 showed radiographic osteoarthritis and 42 were replaced. 91.5% of the hips had follow-up data available. The Shape-Score was a significant predictor of rHOA (odds ratio per decimal increase 5.21, 95%-CI (3.74–7.24)). The prediction model using demographics, physical examination, and radiologists scores demonstrated an AUC of 0.795, 95%-CI (0.757–0.834). After addition of the Shape-Score the AUC rose to 0.864, 95%-CI (0.833–0.895). Conclusions: Our Shape-Score, automatically derived from radiographs using a novel machine learning workflow, may strongly improve risk prediction in hip osteoarthritis

    Measurement of the W ± Z boson pair-production cross section in pp collisions at s = 13  TeV with the ATLAS detector

    Get PDF
    Here, the production of W ±Z events in proton–proton collisions at a centre-of-mass energy of 13 TeV13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb –1. The W ±Z candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons
    • …
    corecore