97 research outputs found
Neoclassical flows in deuterium-helium plasma density pedestals
In tokamak transport barriers, the radial scale of profile variations can be
comparable to a typical ion orbit width, which makes the coupling of the
distribution function across flux surfaces important in the collisional
dynamics. We use the radially global steady-state neoclassical {\delta}f code
Perfect to calculate poloidal and toroidal flows, and radial fluxes, in the
pedestal. In particular, we have studied the changes in these quantities as the
plasma composition is changed from a deuterium bulk species with a helium
impurity to a helium bulk with a deuterium impurity, under specific profile
similarity assumptions. The poloidally resolved radial fluxes are not
divergence-free in isolation in the presence of sharp radial profile
variations, which leads to the appearance of poloidal return-flows. These flows
exhibit a complex radial-poloidal structure that extends several orbit widths
into the core and is sensitive to abrupt radial changes in the ion temperature
gradient. We find that a sizable neoclassical toroidal angular momentum
transport can arise in the radially global theory, in contrast to the local.Comment: 14 pages, 19 figure
Optimization of flux-surface density variation in stellarator plasmas with respect to the transport of collisional impurities
Avoiding impurity accumulation is a requirement for steady-state stellarator
operation. The accumulation of impurities can be heavily affected by variations
in their density on the flux-surface. Using recently derived semi-analytic
expressions for the transport of a collisional impurity species with high-
and flux-surface density-variation in the presence of a low-collisionality bulk
ion species, we numerically optimize the impurity density-variation on the
flux-surface to minimize the radial peaking factor of the impurities. These
optimized density-variations can reduce the core impurity density by
(with the impurity charge number) in the Large Helical Device case
considered here, and by in a Wendelstein 7-X standard configuration
case. On the other hand, when the same procedure is used to find
density-variations that maximize the peaking factor, it is notably increased
compared to the case with no density-variation. This highlights the potential
importance of measuring and controlling these variations in experiments.Comment: 19 figures, 17 pages. Accepted into Nuclear Fusio
A Mixed-Methods Systematic Review: Infidelity, Romantic Jealousy and Intimate Partner Violence against Women.
Infidelity and romantic jealousy (RJ) are commonly cited relational level drivers of intimate partner violence (IPV) but remain undertheorized and underutilized in IPV research and prevention. This global systematic review aims to characterize the existing research on real or suspected infidelity and RJ in relation to IPV and inform future research and programming. We systematically searched 11 databases for peer-reviewed research, published between April 2009 and 2019, that provided data on the prevalence or a measure of association (quantitative), or pathway (qualitative), between real or suspected infidelity or RJ, and IPV. Fifty-one papers from 28 countries were included and the evidence showed a consistent association between real or suspected infidelity, RJ and IPV. Our findings identify three overarching mechanisms and six pathways between infidelity, RJ and IPV. These provide support for prominent theories in the field related to patriarchal culture, threatened masculinities and femininities and a lack of emotional regulation and conflict resolution skills, but not evolutionary theories. Our findings suggest that researchers should use standardized measurement tools that make the distinction between RJ and suspected, confirmed and accusations of infidelity. Policy and programming should aim to transform traditional gender roles, accounting for infidelity and RJ and improving couple's communication and trust
A Mixed-Methods Systematic Review: Infidelity, Romantic Jealousy and Intimate Partner Violence against Women
Infidelity and romantic jealousy (RJ) are commonly cited relational level drivers of intimate partner violence (IPV) but remain undertheorized and underutilized in IPV research and prevention. This global systematic review aims to characterize the existing research on real or suspected infidelity and RJ in relation to IPV and inform future research and programming. We systematically searched 11 databases for peer-reviewed research, published between April 2009 and 2019, that provided data on the prevalence or a measure of association (quantitative), or pathway (qualitative), between real or suspected infidelity or RJ, and IPV. Fifty-one papers from 28 countries were included and the evidence showed a consistent association between real or suspected infidelity, RJ and IPV. Our findings identify three overarching mechanisms and six pathways between infidelity, RJ and IPV. These provide support for prominent theories in the field related to patriarchal culture, threatened masculinities and femininities and a lack of emotional regulation and conflict resolution skills, but not evolutionary theories. Our findings suggest that researchers should use standardized measurement tools that make the distinction between RJ and suspected, confirmed and accusations of infidelity. Policy and programming should aim to transform traditional gender roles, accounting for infidelity and RJ and improving couple's communication and trust
Intimate partner violence against women on the Colombia Ecuador border: a mixed-methods analysis of the liminal migrant experience.
BACKGROUND: Intimate partner violence (IPV) has serious long-term health and psychological consequences and is highly prevalent in Latin America and among displaced populations. Liminality - the ambiguous in-between state of individuals completing a migratory journey - represents a state of legal, economic, and physical insecurity. Through the framework of liminality, this analysis seeks to understand the unique challenges faced by displaced Colombian women in Ecuador including their experience of IPV. METHODS: We performed a secondary analysis of 15 in-depth interviews and 319 longitudinal surveys, conducted on the border of Ecuador and Colombia, following a sequential explanatory mixed-methods design. We analysed interviews thematically and mapped the main themes onto complementary quantitative variables. We conducted logistic regression with identified risk and protective factors (measured at time 1) and recent IPV (measured at time 2), controlling for demographic characteristics and IPV at time 1. RESULTS: Our mixed-methods analysis revealed four main mechanisms by which displacement influenced the social and economic realities of Colombian women years after crossing the border, compounding their risk of IPV and limiting their ability to escape it. Lack of legal residence and documentation, violence experienced along life course and migratory continuums which increased their risk for later revictimisation, social isolation including loss of support networks and restricted mobility and lastly, financial stress. CONCLUSIONS: This research highlights the critical importance of supporting the economic and social integration of migrants and refugees in host communities, as well as the need to carefully consider migration-related vulnerabilities in IPV prevention and response interventions. As the regional refugee crisis grows, policy makers must consider how the long-term marginalisation of refugee women contributes to their victimisation. This research also supports the idea of incorporating gender synchronised, transformative IPV prevention and response programmes into migration-related and poverty alleviation international development efforts
Developing a collaborative agenda for humanities and social scientific research on laboratory animal science and welfare.
Improving laboratory animal science and welfare requires both new scientific research and insights from enquiry in the humanities and social sciences. Whilst scientific research provides evidence to replace, reduce and refine procedures involving laboratory animals (the ‘3Rs’), work in the humanities and social sciences can help understand the social, economic and cultural processes that enhance or impede humane ways of knowing and working with laboratory animals. However, communication across these disciplinary perspectives is currently limited, and they frame questions, generate results, engage users, and seek to influence policy in different ways. To facilitate dialogue and future research at this interface, we convened an interdisciplinary group of 45 life scientists, social scientists, humanities scholars, non-governmental organisations and policy-makers to generate a collaborative research agenda. This drew on other agenda-setting exercises in science policy, using a collaborative and deliberative approach for the identification of research priorities. Participants were recruited from across the community, invited to submit research questions and vote on their priorities. They then met at an interactive workshop in the UK, discussed all 136 questions submitted, and collectively defined the 30 most important issues for the group. The output is a collaborative future agenda for research in the humanities and social sciences on laboratory animal science and welfare. The questions indicate a demand for new research in the humanities and social sciences to inform emerging discussions and priorities on the governance and practice of laboratory animal research, including around: international harmonisation, openness and public engagement, ‘cultures of care’, harm-benefit analysis and the future of the 3Rs. The process underlines the value of interdisciplinary exchange for improving mutual understanding of different research cultures and identifies ways of enhancing the effectiveness of future research at the interface between the humanities, social sciences, science and science policy
The role of gender and romantic jealousy in intimate partner violence against women, a mixed-methods study in Northern Ecuador.
Male romantic jealousy is a commonly cited driver of intimate partner violence against women. An in-depth, contextualised understanding of the pathways and mechanisms from jealousy to intimate partner violence is, however, needed to inform programmes and interventions. We triangulated data from 48 interviews, eight focus groups and 1216 survey findings from low-income married women and men in northern Ecuador. Male jealousy was associated with controlling behaviours (aOR: 14.47, 95% CI: 9.47, 22.12) and sexual intimate partner violence (aOR: 2.4, 95% CI: 1.12, 5.12). Controlling behaviours were associated with physical and sexual intimate partner violence (aOR: 2.16, 95% CI: 1.21, 3.84). Qualitatively we found that most respondents framed jealousy within a discourse of love, and three triggers of male jealousy leading to intimate partner violence were identified: (1) community gossip, which acted as a mechanism of community control over women's movements and sexuality; (2) women joining the labour force, which was quantitatively associated with intimate partner violence and partially mediated by jealousy; and (3) women's refusal to have sex, which could lead husbands to coerce sex through accusations of infidelity. Gender-transformative interventions at the individual, couple and community level providing models of alternative masculinities and femininities may offer promise in reducing intimate partner violence in Ecuador. Importantly, future economic empowerment interventions should address jealousy to mitigate potential intimate partner violence backlash
Comprehensive allostatic load risk index is associated with increased frontal and left parietal white matter hyperintensities in mid-life cognitively healthy adults
To date, there is a considerable heterogeneity of methods to score Allostatic Load (AL). Here we propose a comprehensive algorithm (ALCS) that integrates commonly used approaches to generate AL risk categories and assess associations to brain structure deterioration. In a cohort of cognitively normal mid-life adults (n = 620, age 51.3 ± 5.48 years), we developed a comprehensive composite for AL scoring incorporating gender and age differences, high quartile approach, clinical reference values, and current medications, to then generate AL risk categories. Compared to the empirical approach (ALES), ALCS showed better model fit criteria and a strong association with age and sex. ALSC categories were regressed against brain and white matter hyperintensity (WMH) volumes. Higher AL risk categories were associated with increased total, periventricular, frontal, and left parietal WMH volumes, also showing better fit compared to ALES. When cardiovascular biomarkers were removed from the ALSC algorithm, only left-frontal WMHV remained associated with AL, revealing a strong vascular burden influencing the index. Our results agree with previous evidence and suggest that sustained stress exposure enhances brain deterioration in mid-life adults. Showing better fit than ALES, our comprehensive algorithm can provide a more accurate AL estimation to explore how stress exposure enhances age-related health decline.</p
The pivotal role of sleep in mediating the effects of life stressors and healthy habits on allostatic load in mid-life adults
Objectives: We assessed the modulation of allostatic load (AL) by engagement in healthy habits and life stressors, mediated through resilience and the perceived influence of the stressors. Sleep was included as third mediator given extensive evidence associating to all the analysed factors. Methods: Structural equation models to assess the modulation of AL by either traumatic or psychosocial stressors and healthy habits were generated with data from 620 mid-life adults (age 51.3 ± 5.48 years). Model 1 included self-reported life stressors, engagement in cognitive and physical activities, resilience and a pyramid score for diet. In Model 2, self-reported sleep quality was included in the mediation analysis between resilience and perceived stress on AL. Results: Direct effects of sports and diet on AL, and on resilience by sports were found in all the evaluated models. The modulation of AL by both types of stressors was only revealed in model 2, through indirect effects of perceived influence via sleep quality. An effect of sport habits on AL via resilience was found to be mediated by sleep, and equivalent but opposed effects of perceived influence of stressors and resilience on sleep quality emerged as critical factor for AL modulation. Conclusion: Our results suggest that sleep plays a pivotal role in the modulation of AL by both life stressors and sport habits, balancing the harmful and protective effects of perceived stress and resilience. The relative weight of one over the other to worsen or improve sleep quality will determine the resulting level of AL
The Mediterranean diet is not associated with neuroimaging or cognition in middle‐aged adults: : a cross‐sectional analysis of the PREVENT dementia programme
Funding: The PREVENT dementia programme is funded by the Alzheimer's Society (grant numbers 178, 264 and 329), Alzheimer's Association (grant number TriBEKa-17-519,007) and philanthropic donations. The analytical work was funded by the MRC UK Nutrition Research Partnership (NRP) Collaboration Award (MR/T001852/1). Professor Muniz-Terrera acknowledges the support of the Osteopathic Heritage Foundation through funding for the Osteopathic Heritage Foundation Ralph S. Licklider, D.O., Research Endowment in the Heritage College of Osteopathic Medicine.Background and purpose The Mediterranean diet (MedDiet) has been associated with reduced dementia incidence in several studies. It is important to understand if diet is associated with brain health in midlife, when Alzheimer's disease and related dementias are known to begin. Methods This study used data from the PREVENT dementia programme. Three MedDiet scores were created (the Pyramid, Mediterranean Diet Adherence Screener [MEDAS] and MEDAS continuous) from a self‐reported food frequency questionnaire. Primary outcomes were hippocampal volume and cube‐transformed white matter hyperintensity volume. Secondary outcomes included cornu ammonis 1 and subiculum hippocampal subfield volumes, cortical thickness and measures of cognition. Sex‐stratified analyses were run to explore differential associations between diet and brain health by sex. An exploratory path analysis was conducted to study if any associations between diet and brain health were mediated by cardiovascular risk factors for dementia. Results In all, 504 participants were included in this analysis, with a mean Pyramid score of 8.10 (SD 1.56). There were no significant associations between any MedDiet scoring method and any of the primary or secondary outcomes. There were no differences by sex in any analyses and no significant mediation between the Pyramid score and global cognition by cardiovascular risk factors. Conclusions Overall, this study did not find evidence for an association between the MedDiet and either neuroimaging or cognition in a midlife population study. Future work should investigate associations between the MedDiet and Alzheimer's disease and related dementias biomarkers as well as functional neuroimaging in a midlife population.Peer reviewe
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