231 research outputs found

    Parenting and child development in families with a child conceived through embryo donation

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    Concerns have been raised regarding the potentially negative effects of conception using donated embryos on parenting and child development. Findings are presented of an exploratory study of families with a child conceived through embryo donation. Twenty-one embryo donation families were compared with 28 adoptive families and 30 in vitro fertilization families on standardized interview and questionnaire measures of the parents' marital and psychological state, the quality of parent-child relationships, and the child's development. In all 3 groups, the children were aged 2-5 years. The differences indicated higher emotional overinvolvement and defensive responding in the embryo donation families, along with greater secrecy about the child's origins. The children were not at increased risk of psychological problems. The study provides interesting but preliminary findings on parent-child relationships and child development in a new family form

    Hydrogen bonding and the stability of the polypeptide backbone

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    The tertiary structures of globular proteins are crucial in determining reactivity and specificity as biological catalysts and signalling systems. The rules determining the final fold of a protein are still unknown, but some progress has been made in defining tertiary structure in terms of the secondary structure, the conformation of the polypeptide chain. Perhaps surprisingly, not all of the conformational properties of this backbone are known, and several new approaches to studying these are described. Most studies of peptide structure have focused on hydrogen bonding, and this is used as a starting point for this study. Different descriptions of the hydrogen bond, from geometric rules to ab initio calculations, are considered, and an approach based on analysing contributions of individual polar groups to the potential energy using semi empirical Lennard-Jones calculations is chosen on grounds of accuracy, flexibility, and ease of calculation. Using this approach, it is shown that electrostatic interactions between main chain atoms stabilise the right handed twist found in Beta-strands and similar interactions between main-chain atoms not hydrogen bonded to each other influence the geometries of hydrogen bonds in Alpha-helices and Beta-sheets. A role for water and tertiary hydrogen bonds in determining backbone conformation is suggested. The same technique makes it possible to investigate interatomic repulsions as well as attractions. A detailed analysis of the attractions and repulsions in an idealised polypeptide explains many of the features of helical structures in proteins, and suggests a hitherto unexpected directional helix forming pathway, which is supported by a range of kinetic and structural data. Software for automated searching of a hydrogen bond database is developed, and used to identify hydrogen bonded rings formed by amide side chains and main chain peptides. Integrating the database with novel visualisation techniques allows a previously unidentified property of beta sheets, the hydrophobic ridge, to be detected. A range of different computational approaches was used surging this research, from molecular modelling to database searching. Several pieces of software were developed, and these are described together with some observations about the types of software and working environments which were found to be useful in structural biochemistry, and what types of software technology could be developed to make this task easier

    Increasing numbers of harbour seals and grey seals in the Solent

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    Harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) both occur within the UK, but display regional contrasting population trends. While grey seals are typically increasing in number, harbour seals have shown varying trends in recent decades following repeated pandemics. There is a need for monitoring of regional and local populations to understand overall trends. This study utilized a 20-year dataset of seal counts from two neighboring harbours in the Solent region of south England. Generalized additive models showed a significant increase in the numbers of harbour (mean 5.3–30.5) and grey (mean 0–12.0) seals utilizing Chichester Harbour. Conversely, in Langstone Harbour there has been a slight decrease in the number of harbour seals (mean 5.3–4.0). Accompanying photographic data from 2016 to 18 supports the increase in seal numbers within Chichester Harbour, with a total of 68 harbour and 8 grey seals identified. These data also show evidence of site fidelity of harbour seals in this area, with almost a quarter of animals resighted within the past three years. Overall, this long-term study indicates an increasing number of both harbour and grey seals within the Solent. However, more research is required to identify the drivers of this trend.</p

    Psychology of Game Design: Intrinsic and Extrinsic Rewards

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    In this paper, I take an overview of the convergence between psychology and game design, particularly the use of intrinsic and extrinsic rewards in game design

    Measuring Metacognition in Cancer: Validation of the Metacognitions Questionnaire 30 (MCQ-30)

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    Objective The Metacognitions Questionnaire 30 assesses metacognitive beliefs and processes which are central to the metacognitive model of emotional disorder. As recent studies have begun to explore the utility of this model for understanding emotional distress after cancer diagnosis, it is important also to assess the validity of the Metacognitions Questionnaire 30 for use in cancer populations. Methods 229 patients with primary breast or prostate cancer completed the Metacognitions Questionnaire 30 and the Hospital Anxiety and Depression Scale pre-treatment and again 12 months later. The structure and validity of the Metacognitions Questionnaire 30 were assessed using factor analyses and structural equation modelling. Results Confirmatory and exploratory factor analyses provided evidence supporting the validity of the previously published 5-factor structure of the Metacognitions Questionnaire 30. Specifically, both pre-treatment and 12 months later, this solution provided the best fit to the data and all items loaded on their expected factors. Structural equation modelling indicated that two dimensions of metacognition (positive and negative beliefs about worry) were significantly associated with anxiety and depression as predicted, providing further evidence of validity. Conclusions These findings provide initial evidence that the Metacognitions Questionnaire 30 is a valid measure for use in cancer populations

    A metadata approach for clinical data management in translational genomics studies in breast cancer.

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    BACKGROUND: In molecular profiling studies of cancer patients, experimental and clinical data are combined in order to understand the clinical heterogeneity of the disease: clinical information for each subject needs to be linked to tumour samples, macromolecules extracted, and experimental results. This may involve the integration of clinical data sets from several different sources: these data sets may employ different data definitions and some may be incomplete. METHODS: In this work we employ semantic web techniques developed within the CancerGrid project, in particular the use of metadata elements and logic-based inference to annotate heterogeneous clinical information, integrate and query it. RESULTS: We show how this integration can be achieved automatically, following the declaration of appropriate metadata elements for each clinical data set; we demonstrate the practicality of this approach through application to experimental results and clinical data from five hospitals in the UK and Canada, undertaken as part of the METABRIC project (Molecular Taxonomy of Breast Cancer International Consortium). CONCLUSION: We describe a metadata approach for managing similarities and differences in clinical datasets in a standardized way that uses Common Data Elements (CDEs). We apply and evaluate the approach by integrating the five different clinical datasets of METABRIC.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Invariants of the Riemann tensor for Class B Warped Product Spacetimes

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    We use the computer algebra system \textit{GRTensorII} to examine invariants polynomial in the Riemann tensor for class BB warped product spacetimes - those which can be decomposed into the coupled product of two 2-dimensional spaces, one Lorentzian and one Riemannian, subject to the separability of the coupling: ds2=dsΣ12(u,v)+C(xγ)2dsΣ22(θ,ϕ)ds^2 = ds_{\Sigma_1}^2 (u,v) + C(x^\gamma)^2 ds_{\Sigma_2}^2 (\theta,\phi) with C(xγ)2=r(u,v)2w(θ,ϕ)2C(x^\gamma)^2=r(u,v)^2 w(\theta,\phi)^2 and sig(Σ1)=0,sig(Σ2)=2ϵ(ϵ=±1)sig(\Sigma_1)=0, sig(\Sigma_2)=2\epsilon (\epsilon=\pm 1) for class B1B_{1} spacetimes and sig(Σ1)=2ϵ,sig(Σ2)=0sig(\Sigma_1)=2\epsilon, sig(\Sigma_2)=0 for class B2B_{2}. Although very special, these spaces include many of interest, for example, all spherical, plane, and hyperbolic spacetimes. The first two Ricci invariants along with the Ricci scalar and the real component of the second Weyl invariant JJ alone are shown to constitute the largest independent set of invariants to degree five for this class. Explicit syzygies are given for other invariants up to this degree. It is argued that this set constitutes the largest functionally independent set to any degree for this class, and some physical consequences of the syzygies are explored.Comment: 19 pages. To appear in Computer Physics Communications Thematic Issue on "Computer Algebra in Physics Research". Uses Maple2e.st

    Shear-free perfect fluids with a solenoidal electric curvature

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    We prove that the vorticity or the expansion vanishes for any shear-free perfect fluid solution of the Einstein field equations where the pressure satisfies a barotropic equation of state and the spatial divergence of the electric part of the Weyl tensor is zero.Comment: 9 page
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