1,226 research outputs found

    Auditory feedback control mechanisms do not contribute to cortical hyperactivity within the voice production network in adductor spasmodic dysphonia

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    Adductor spasmodic dysphonia (ADSD), the most common form of spasmodic dysphonia, is a debilitating voice disorder characterized by hyperactivity and muscle spasms in the vocal folds during speech. Prior neuroimaging studies have noted excessive brain activity during speech in ADSD participants compared to controls. Speech involves an auditory feedback control mechanism that generates motor commands aimed at eliminating disparities between desired and actual auditory signals. Thus, excessive neural activity in ADSD during speech may reflect, at least in part, increased engagement of the auditory feedback control mechanism as it attempts to correct vocal production errors detected through audition. To test this possibility, functional magnetic resonance imaging was used to identify differences between ADSD participants and age-matched controls in (i) brain activity when producing speech under different auditory feedback conditions, and (ii) resting state functional connectivity within the cortical network responsible for vocalization. The ADSD group had significantly higher activity than the control group during speech (compared to a silent baseline task) in three left-hemisphere cortical regions: ventral Rolandic (sensorimotor) cortex, anterior planum temporale, and posterior superior temporal gyrus/planum temporale. This was true for speech while auditory feedback was masked with noise as well as for speech with normal auditory feedback, indicating that the excess activity was not the result of auditory feedback control mechanisms attempting to correct for perceived voicing errors in ADSD. Furthermore, the ADSD group had significantly higher resting state functional connectivity between sensorimotor and auditory cortical regions within the left hemisphere as well as between the left and right hemispheres, consistent with the view that excessive motor activity frequently co-occurs with increased auditory cortical activity in individuals with ADSD.First author draf

    A new approach to diagnosing and researching developmental prosopagnosia:Excluded cases are impaired too

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    Developmental prosopagnosia is characterized by severe, lifelong difficulties when recognizing facial identity. Unfortunately, the most common diagnostic assessment (Cambridge Face Memory Test) misses 50–65% of individuals who believe that they have this condition. This results in such excluded cases’ absence from scientific knowledge, effect sizes of impairment potentially overestimated, treatment efficacy underrated, and may elicit in them a negative experience of research. To estimate their symptomology and group-level impairments in face processing, we recruited a large cohort who believes that they have prosopagnosia. Matching prior reports, 56% did not meet criteria on the Cambridge Face Memory Test. However, the severity of their prosopagnosia symptoms and holistic perception deficits were comparable to those who did meet criteria. Excluded cases also exhibited face perception and memory impairments that were roughly one standard deviation below neurotypical norms, indicating the presence of objective problems. As the prosopagnosia index correctly classified virtually every case, we propose it should be the primary method for providing a diagnosis, prior to subtype categorization. We present researchers with a plan on how they can analyze these excluded prosopagnosia cases in their future work without negatively impacting their traditional findings. We anticipate such inclusion will enhance scientific knowledge, more accurately estimate effect sizes of impairments and treatments, and identify commonalities and distinctions between these different forms of prosopagnosia. Owing to their atypicalities in visual perception, we recommend that the prosopagnosia index should be used to screen out potential prosopagnosia cases from broader vision research

    Discussing parenthood with gay men diagnosed with HIV: a qualitative study of patient and healthcare practitioner perspectives.

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    BACKGROUND: Research on HIV and reproduction has focused largely on women and heterosexual men. This article examines whether it is relevant to address parenthood in HIV care with gay men and what ways of doing so are most appropriate. METHODS: Qualitative interviews were conducted at four London clinics with 25 men living with HIV, aged 20-45, who did not have children, and 16 HIV clinicians. A thematic analysis identified potential reasons why parenthood was rarely discussed with gay men in HIV care. RESULTS: Two sets of ideas contributed to a lack of conversations about parenthood: clinicians' ideas about what matters to gay men and men's ideas about what it means to be HIV-positive. Both sets of ideas largely excluded having children, with patients and practitioners similarly unlikely to raise the topic of parenthood in the clinic. Contrary to what clinician commonly assumed, many men expressed interest in receiving more information, highlighting the importance of reassuring people upon diagnosis that it is possible to become parents while living with HIV. CONCLUSIONS: Parenting desires and intentions were rarely discussed with men in HIV care. Our findings illuminate the potentially beneficial effects of emphasising that having children is a possibility at diagnosis, regardless of patients' gender or sexuality. Conveying this information seems meaningful, not only to men who want to become parents in the future but also to others, as it appears to alleviate fears about mortality and ill health.British HIV Association Isaac Newton Trust Leverhulme Trust (ECF-2018-146) Wellcome Trust (100606/Z/12/Z

    The Role of Entrepreneur-Venture Fit in Online Home-based Entrepreneurship: A Systematic Literature Review

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    Home-based businesses and their founders represent an important, but under-researched facet of entrepreneurship. Far from being small, hobby-businesses with little economic impact, home-based business make significant contribution to national economies in terms of both turnover and employment. Online home-based businesses have been recognised as an important and distinct sector of the home-based business domain, offering unique opportunity for innovation and business diversity. The paper presents a systematic literature review of extant research on online home-based entrepreneurs and their businesses. The findings of the review are structured and discussed using the theoretical lens of entrepreneur-venture fit. Use of this lens allows the study to bring coherence to previously fragmented extant studies, providing a basis for future research in this domain. The study also develops a novel model of entrepreneur-venture fit in the specific case of online home-based businesses. This allows us to suggest five positive interactions between entrepreneurial and venture characteristics. It also allows us to suggest a number of previously unidentified negative interactions, which may result in entrepreneurs becoming ‘locked-in’ and suffering multiple sources of stress

    Chandra Observation of the Cluster Environment of a WAT Radio Source in Abell 1446

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    Wide-angle tail (WAT) radio sources are often found in the centers of galaxy clusters where intracluster medium (ICM) ram pressure may bend the lobes into their characteristic C-shape. We examine the low redshift (z=0.1035) cluster Abell 1446, host to the WAT radio source 1159+583. The cluster exhibits possible evidence for a small-scale cluster-subcluster merger as a cause of the WAT radio source morphology. This evidence includes the presence of temperature and pressure substructure along the line that bisects the WAT as well as a possible wake of stripped interstellar material or a disrupted cool core to the southeast of the host galaxy. A filament to the north may represent cool, infalling gas that's contributing to the WAT bending while spectroscopically determined redshifts of member galaxies may indicate some component of a merger occurring along the line-of-sight. The WAT model of high flow velocity and low lobe density is examined as another scenario for the bending of 1159+583. It has been argued that such a model would allow the ram pressure due to the galaxy's slow motion through the ICM to shape the WAT source. A temperature profile shows that the cluster is isothermal (kT= 4.0 keV) in a series of annuli reaching a radius of 400 kpc. There is no evidence of an ongoing cooling flow. Temperature, abundance, pressure, density, and mass profiles, as well as two-dimensional maps of temperature and pressure are presented.Comment: 40 AASTeX pages including 15 postscript figures; accepted for publication in Ap

    Spatiotemporal and plantar pressure patterns of 1000 healthy individuals aged 3-101 years

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    Objective The purpose of this study was to establish normative reference values for spatiotemporal and plantar pressure parameters, and to investigate the influence of demographic, anthropometric and physical characteristics. Methods In 1000 healthy males and females aged 3–101 years, spatiotemporal and plantar pressure data were collected barefoot with the Zeno™ walkway and Emed® platform. Correlograms were developed to visualise the relationships between widely reported spatiotemporal and pressure variables with demographic (age, gender), anthropometric (height, mass, waist circumference) and physical characteristics (ankle strength, ankle range of motion, vibration perception) in children aged 3–9 years, adolescents aged 10–19 years, adults aged 20–59 years and older adults aged over 60 years. Results A comprehensive catalogue of 31 spatiotemporal and pressure variables were generated from 1000 healthy individuals. The key findings were that gait velocity was stable during adolescence and adulthood, while children and older adults walked at a comparable slower speed. Peak pressures increased during childhood to older adulthood. Children demonstrated highest peak pressures beneath the rearfoot whilst adolescents, adults and older adults demonstrated highest pressures at the forefoot. Main factors influencing spatiotemporal and pressure parameters were: increased age, height, body mass and waist circumference, as well as ankle dorsiflexion and plantarflexion strength. Conclusion This study has established whole of life normative reference values of widely used spatiotemporal and plantar pressure parameters, and revealed changes to be expected across the lifespan

    Health on the Move (HOME) Study: Using a smartphone app to explore the health and wellbeing of migrants in the United Kingdom.

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    Background/Aim: We have a limited understanding of the broader determinants of health of international migrants and how these change over time since migration to the United Kingdom (UK). To address this knowledge gap, we aim to conduct a prospective cohort study with data acquisition via a smartphone application (app). In this pilot study, we aim to 1) determine the feasibility of the use of an app for data collection in international migrants, 2) optimise app engagement by quantifying the impact of specific design features on the completion rates of survey questionnaires and on study retention, 3) gather preliminary profile health status data, to begin to examine how risk factors for health are distributed among migrants. Methods: We will recruit 275 participants through a social media campaign and through third sector organisations that work with or support migrants in the UK. Following consent and registration, data will be collected via surveys. To optimise app engagement and study retention, we will quantify the impact of specific design features (i.e. the frequency of survey requests, the time of day for app notifications, the frequency of notifications, and the wording of notifications) via micro-randomised process evaluations. The primary outcome for this study is survey completion rates with numerator as the number of surveys completed and denominator as the total number of available surveys. Secondary outcomes are study retention rates and ratings of interest after app usage. Ethics and dissemination: We have obtained approval to use consented patient identifiable data from the University College London Ethics Committee. Improving engagement with the app and gathering preliminary health profile data will help us identify accessibility and usability issues and other barriers to app and study engagement prior to moving to a larger study

    1000 Norms Project: Protocol of a cross-sectional study cataloging human variation

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    Background Clinical decision-making regarding diagnosis and management largely depends on comparison with healthy or ‘normal’ values. Physiotherapists and researchers therefore need access to robust patient-centred outcome measures and appropriate reference values. However there is a lack of high-quality reference data for many clinical measures. The aim of the 1000 Norms Project is to generate a freely accessible database of musculoskeletal and neurological reference values representative of the healthy population across the lifespan. Methods/design In 2012 the 1000 Norms Project Consortium defined the concept of ‘normal’, established a sampling strategy and selected measures based on clinical significance, psychometric properties and the need for reference data. Musculoskeletal and neurological items tapping the constructs of dexterity, balance, ambulation, joint range of motion, strength and power, endurance and motor planning will be collected in this cross-sectional study. Standardised questionnaires will evaluate quality of life, physical activity, and musculoskeletal health. Saliva DNA will be analysed for the ACTN3 genotype (‘gene for speed’). A volunteer cohort of 1000 participants aged 3 to 100 years will be recruited according to a set of self-reported health criteria. Descriptive statistics will be generated, creating tables of mean values and standard deviations stratified for age and gender. Quantile regression equations will be used to generate age charts and age-specific centile values. Discussion This project will be a powerful resource to assist physiotherapists and clinicians across all areas of healthcare to diagnose pathology, track disease progression and evaluate treatment response. This reference dataset will also contribute to the development of robust patient-centred clinical trial outcome measures
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