94 research outputs found

    Data compression and regression based on local principal curves.

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    Frequently the predictor space of a multivariate regression problem of the type y = m(x_1, …, x_p ) + ε is intrinsically one-dimensional, or at least of far lower dimension than p. Usual modeling attempts such as the additive model y = m_1(x_1) + … + m_p (x_p ) + ε, which try to reduce the complexity of the regression problem by making additional structural assumptions, are then inefficient as they ignore the inherent structure of the predictor space and involve complicated model and variable selection stages. In a fundamentally different approach, one may consider first approximating the predictor space by a (usually nonlinear) curve passing through it, and then regressing the response only against the one-dimensional projections onto this curve. This entails the reduction from a p- to a one-dimensional regression problem. As a tool for the compression of the predictor space we apply local principal curves. Taking things on from the results presented in Einbeck et al. (Classification – The Ubiquitous Challenge. Springer, Heidelberg, 2005, pp. 256–263), we show how local principal curves can be parametrized and how the projections are obtained. The regression step can then be carried out using any nonparametric smoother. We illustrate the technique using data from the physical sciences

    Data compression and regression based on local principal curves

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    Frequently the predictor space of a multivariate regression problem of the type y = m(x_1, …, x_p ) + ε is intrinsically one-dimensional, or at least of far lower dimension than p. Usual modeling attempts such as the additive model y = m_1(x_1) + … + m_p (x_p ) + ε, which try to reduce the complexity of the regression problem by making additional structural assumptions, are then inefficient as they ignore the inherent structure of the predictor space and involve complicated model and variable selection stages. In a fundamentally different approach, one may consider first approximating the predictor space by a (usually nonlinear) curve passing through it, and then regressing the response only against the one-dimensional projections onto this curve. This entails the reduction from a p- to a one-dimensional regression problem. As a tool for the compression of the predictor space we apply local principal curves. Taking things on from the results presented in Einbeck et al. (Classification – The Ubiquitous Challenge. Springer, Heidelberg, 2005, pp. 256–263), we show how local principal curves can be parametrized and how the projections are obtained. The regression step can then be carried out using any nonparametric smoother. We illustrate the technique using data from the physical sciences

    Pathways to help-seeking for sexual difficulties in older adults: qualitative findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

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    Background Older adults are at an increased risk of sexual difficulties due to ageing and chronic health conditions. While they experience barriers to seeking and receiving help for sexual difficulties there is a dearth of research about the help-seeking journey. Objective To explore decision-making in context; particularly, the reasons why older adults do, or do not, seek help for sexual difficulties. Methods Semi-structured interviews were conducted with 11 men and 12 women aged 58–75 who reported having a health condition, disability or medication that had affected their sex life in the last year. Participants were part of the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Data were analysed thematically. Results Help-seeking was rarely a predictable or linear process. Participants tended to wait and see if the sexual difficulty got better on its own or improved as a result of lifestyle changes. An often-lengthy period of thinking, researching and planning could end with a decision to seek professional help, to not seek help, or do nothing for now. A significant barrier was concern about the interaction of medicines prescribed for the sexual difficulty with those already taken for chronic health conditions. Patient fear of not being taken seriously and doctor reticence to ask thwarted potential conversations. Help-seeking journeys often ended without resolution, even when professional help was sought. Conclusions To give patients and practitioners permission to raise the topic, suggestions include providing patients with a pre-consultation card which lists topics they would like to talk about, including sexual issues

    Lesbian and bisexual women's human rights, sexual rights and sexual citizenship: negotiating sexual health in England.

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    Lesbian and bisexual women's sexual health is neglected in much Government policy and practice in England and Wales. This paper examines lesbian and bisexual women's negotiation of sexual health, drawing on findings from a small research project. Themes explored include invisibility and lack of information, influences on decision-making and sexual activities and experiences of services and barriers to sexual healthcare. Key issues of importance in this respect are homophobic and heterosexist social contexts. Drawing on understandings of lesbian, gay and bisexual human rights, sexual rights and sexual citizenship, it is argued that these are useful lenses through which to examine and address lesbian and bisexual women's sexual health and related inequalities

    Sexuality and Affection among Elderly German Men and Women in Long-Term Relationships: Results of a Prospective Population-Based Study

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The study was funded by the German Federal Ministry for Families, Senior Citizens, Women and Youth (AZ 314-1722-102/16; AZ 301-1720-295/2), the Ministry for Science, Research and Art Baden-Württemberg, and the University of Rostock (FORUN 989020; 889048)

    Nested radiations and the pulse of angiosperm diversification: increased diversification rates often follow whole genome duplications

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111924/1/nph13491-sup-0001-FigS1-TableS1-S2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111924/2/nph13491.pd

    Are dementia services and support organisations meeting the needs of Lesbian, Gay, Bisexual and Transgender (LGBT) caregivers of LGBT people living with dementia? A scoping review of the literature

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    Objectives More than 60% of people with dementia live at home, where assistance is usually provided by informal caregivers. Research on the experiences of the Lesbian, Gay, Bisexual and Transgender (LGBT) caregivers is limited. This scoping review of the literature synthesizes international evidence on support provision for the population of LGBT caregivers. Methods Eight electronic databases and Google Scholar were searched using terms including ‘Dementia’, ‘LGBT’ and ‘Caregiver’ for all types of articles, including empirical studies, grey literature and sources from charity/third sector/lobbying organisations. Article selection was performed by two raters. Data were analysed through deductive thematic analysis, and three themes were established a priori: Distinct experiences of LGBT caregivers; current barriers to support; strategies to overcome the current challenges. Results Twenty articles were included. Distinct experiences of LGBT caregivers included a loss of LGBT identity, the impact of historical events, families of choice, and disclosing LGBT identities. Current barriers to support included poor representation of LGBT caregivers in support services, negative attitudes of staff and reluctance of caregivers to seek support. Strategies to overcome the current challenges included staff awareness training and kite-marking inclusion. Conclusion Limited cultural competency of staff and a subsequent reluctance to seek help have an impact on use of support services among LGBT caregivers. Implications for practice include the development of cost-effective, feasible, and acceptable inclusiveness training for services. Implications for policy include implementation in organisations of top-down agendas supporting staff to understand sexuality and non-heteronormative relationships in older age

    Health care professionals' views on discussing sexual wellbeing with patients who have had a stroke: A qualitative study

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    OBJECTIVES: To examine the experiences of health care professionals discussing sexual wellbeing with patients who have had a stroke. DESIGN: In-depth qualitative interview study with purposive sampling and thematic analysis. PARTICIPANTS: 30 health care professionals purposively recruited to include different roles and settings along the stroke patient pathway in secondary and primary care. SETTING: Two hospitals and three general practices in the West Midlands, UK. RESULTS: Sexual wellbeing was a topic that participants did not raise with patients and was infrequently raised by patients. Barriers to raising discussion were on four levels: structural, health care professional, patient, and professional-patient interface. Barriers within these levels included: sexual wellbeing not present within hospital stroke policy; the perception that sexual wellbeing was not within participants' role; participants' concern that raising the issue could cause harm to the patient; and the views that discussion would be inappropriate with older people or unimportant to women. Resources exist to aid discussion but many participants were unaware of them, and most of those that were, did not use them routinely. CONCLUSIONS: Participants lacked motivation, ownership, and the confidence and skills to raise sexual wellbeing routinely after stroke. Similar findings have been reported in cancer care and other taboo subjects such as incontinence potentially resulting in a sub-optimal experience for patients. Normalisation of the inclusion of sensitive topics in discussions post-stroke does not seem to need significant structural intervention and simple changes such as information provision and legitimisation through consideration of the issue in standard care policies may be all that is required. The experiences recounted by professionals in this study suggest that such changes are needed now

    The bien r package: A tool to access the Botanical Information and Ecology Network (BIEN) database

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    There is an urgent need for largeâ scale botanical data to improve our understanding of community assembly, coexistence, biogeography, evolution, and many other fundamental biological processes. Understanding these processes is critical for predicting and handling humanâ biodiversity interactions and global change dynamics such as food and energy security, ecosystem services, climate change, and species invasions.The Botanical Information and Ecology Network (BIEN) database comprises an unprecedented wealth of cleaned and standardised botanical data, containing roughly 81 million occurrence records from c. 375,000 species, c. 915,000 trait observations across 28 traits from c. 93,000 species, and coâ occurrence records from 110,000 ecological plots globally, as well as 100,000 range maps and 100 replicated phylogenies (each containing 81,274 species) for New World species. Here, we describe an r package that provides easy access to these data.The bien r package allows users to access the multiple types of data in the BIEN database. Functions in this package query the BIEN database by turning user inputs into optimised PostgreSQL functions. Function names follow a convention designed to make it easy to understand what each function does. We have also developed a protocol for providing customised citations and herbarium acknowledgements for data downloaded through the bien r package.The development of the BIEN database represents a significant achievement in biological data integration, cleaning and standardization. Likewise, the bien r package represents an important tool for open science that makes the BIEN database freely and easily accessible to everyone.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142458/1/mee312861_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142458/2/mee312861.pd

    Later life sex and Rubin’s ‘Charmed Circle'

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    Gayle Rubin’s now classic concept of the ‘charmed circle’ has been much used by scholars of sexuality to discuss the ways in which some types of sex are privileged over others. In this paper, I apply the concept of the charmed circle to a new topic– later life – in order both to add to theory about later life sex and to add an older-age lens to thinking about sex hierarchies. Traditional discursive resources around older people’s sexual activities, which treat older people’s sex as inherently beyond the charmed circle, now coexist with new imperatives for older people to remain sexually active as part of a wider project of ‘successful’ or ‘active’ ageing. Drawing on the now-substantial academic literature about later life sex, I discuss some of the ways in which redrawing the charmed circle to include some older people’s sex may paradoxically entail the use of technologies beyond the charmed circle of ‘good, normal, natural, blessed’ sex. Sex in later life also generates some noteworthy inversions in which types of sex are privileged and which treated as less desirable, in relation to marriage and procreation. Ageing may, furthermore, make available new possibilities to redefine what constitutes ‘good’ sex and to refuse compulsory sexuality altogether, without encountering stigma
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