1,550 research outputs found

    Structural modifications and corrosion behavior of martensitic stainless steel nitrided by plasma immersion ion implantation

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    In this work we report a study of the structural modifications and corrosion behavior of martensitic stainless steels (MSS) nitrided by plasma immersion ion implantation (PI3). The samples were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, photoemission electron spectroscopy, and potentiodynamic electrochemical measurements. Depending on the PI3 treatment temperature, three different material property trends are observed. At lower implantation temperatures (e.g., 360 °C), the material corrosion resistance is improved and a compact phase of epsilon-(Fe,Cr)3N, without changes in the crystal morphology, is obtained. At intermediate temperatures (e.g., 430 °C), CrN precipitates form principally at grain boundaries, leading to a degradation in the corrosion resistance compared to the original MSS material. At higher temperatures (e.g., 500 °C), the relatively great mobility of the nitrogen and chromium in the matrix induced random precipitates of CrN, transforming the original martensitic phase into alpha-Fe (ferrite), and causing a further degradation in the corrosion resistanc

    The potential health impact of restricting less-healthy food and beverage advertising on UK television between 05.30 and 21.00 hours: A modelling study

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    Funder: National Institute for Health Research; funder-id: http://dx.doi.org/10.13039/501100000272Funder: British AcademyBackground: Restrictions on the advertising of less-healthy foods and beverages is seen as one measure to tackle childhood obesity and is under active consideration by the UK government. Whilst evidence increasingly links this advertising to excess calorie intake, understanding of the potential impact of advertising restrictions on population health is limited. Methods and findings: We used a proportional multi-state life table model to estimate the health impact of prohibiting the advertising of food and beverages high in fat, sugar, and salt (HFSS) from 05.30 hours to 21.00 hours (5:30 AM to 9:00 PM) on television in the UK. We used the following data to parameterise the model: children’s exposure to HFSS advertising from AC Nielsen and Broadcasters’ Audience Research Board (2015); effect of less-healthy food advertising on acute caloric intake in children from a published meta-analysis; population numbers and all-cause mortality rates from the Human Mortality Database for the UK (2015); body mass index distribution from the Health Survey for England (2016); disability weights for estimating disability-adjusted life years (DALYs) from the Global Burden of Disease Study; and healthcare costs from NHS England programme budgeting data. The main outcome measures were change in the percentage of the children (aged 5–17 years) with obesity defined using the International Obesity Task Force cut-points, and change in health status (DALYs). Monte Carlo analyses was used to estimate 95% uncertainty intervals (UIs). We estimate that if all HFSS advertising between 05.30 hours and 21.00 hours was withdrawn, UK children (n = 13,729,000), would see on average 1.5 fewer HFSS adverts per day and decrease caloric intake by 9.1 kcal (95% UI 0.5–17.7 kcal), which would reduce the number of children (aged 5–17 years) with obesity by 4.6% (95% UI 1.4%–9.5%) and with overweight (including obesity) by 3.6% (95% UI 1.1%–7.4%) This is equivalent to 40,000 (95% UI 12,000–81,000) fewer UK children with obesity, and 120,000 (95% UI 34,000–240,000) fewer with overweight. For children alive in 2015 (n = 13,729,000), this would avert 240,000 (95% UI 65,000–530,000) DALYs across their lifetime (i.e., followed from 2015 through to death), and result in a health-related net monetary benefit of £7.4 billion (95% UI £2.0 billion–£16 billion) to society. Under a scenario where all HFSS advertising is displaced to after 21.00 hours, rather than withdrawn, we estimate that the benefits would be reduced by around two-thirds. This is a modelling study and subject to uncertainty; we cannot fully and accurately account for all of the factors that would affect the impact of this policy if implemented. Whilst randomised trials show that children exposed to less-healthy food advertising consume more calories, there is uncertainty about the nature of the dose–response relationship between HFSS advertising and calorie intake. Conclusions: Our results show that HFSS television advertising restrictions between 05.30 hours and 21.00 hours in the UK could make a meaningful contribution to reducing childhood obesity. We estimate that the impact on childhood obesity of this policy may be reduced by around two-thirds if adverts are displaced to after 21.00 hours rather than being withdrawn

    The Micro-Randomized Trial for Developing Digital Interventions: Data Analysis Methods

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    Although there is much excitement surrounding the use of mobile and wearable technology for the purposes of delivering interventions as people go through their day-to-day lives, data analysis methods for constructing and optimizing digital interventions lag behind. Here, we elucidate data analysis methods for primary and secondary analyses of micro-randomized trials (MRTs), an experimental design to optimize digital just-in-time adaptive interventions. We provide a definition of causal "excursion" effects suitable for use in digital intervention development. We introduce the weighted and centered least-squares (WCLS) estimator which provides consistent causal excursion effect estimators for digital interventions from MRT data. We describe how the WCLS estimator along with associated test statistics can be obtained using standard statistical software such as SAS or R. Throughout we use HeartSteps, an MRT designed to increase physical activity among sedentary individuals, to illustrate potential primary and secondary analyses

    Occupational therapy, loneliness and social isolation : a thematic review of the literature

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    Background/Aims: Loneliness and social isolation are thought to have a negative impact on health and wellbeing. There is little literature that provides an explicit focus on loneliness and social isolation in occupational therapy practice. The aim of this study was to explore themes related to loneliness and social isolation in occupational therapy-related literature and consider the implications for practice. Methods: CINAHL, Medline, Pub Med, AMed, PsycINFO, TRIP Database, and Science direct and Web of science databases were used to identify articles pertaining to occupational therapy, loneliness and social isolation. Results: A total of 20 articles were included and three themes were identified: loneliness and social isolation are detrimental to health and wellbeing; factors associated with increased loneliness and social isolation; factors that protect against the impact of loneliness and social isolation. Conclusions: Loneliness and social isolation have a significant impact on the health and wellbeing of the people occupational therapists work with. Occupational therapy practice should include the recognition and assessment of loneliness and social isolation, and interventions to help reduce any impacts on health and wellbeing

    Wasp controls oriented migration of endothelial cells to achieve functional vascular patterning

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    Endothelial cell migration and proliferation are essential for the establishment of a hierarchical organization of blood vessels and optimal distribution of blood. However, how these cellular processes are coordinated remains unknown. Here, using the zebrafish trunk vasculature we show that in future veins endothelial cells proliferate more than in future arteries and migrate preferentially towards neighboring arteries. In future arteries endothelial cells show a biphasic migration profile. During sprouting cells move away from the dorsal aorta, during remodelling cells stop or move towards the feeding aorta. The final morphology of blood vessels is thus established by local proliferation and oriented cell migration to and from neighboring vessels. Additionally, we identify WASp to be essential for this differential migration. Loss of WASp leads to irregular distribution of endothelial cells, substantially enlarged veins and persistent arteriovenous shunting. Mechanistically, we report that WASp drives the assembly of junctional associated actin filaments and is required for junctional expression of PECAM-1. Together, our data identify that functional vascular patterning in the zebrafish trunk utilizes differential cell movement regulated by junctional actin, and that interruption of differential migration may represent a pathomechanism in vascular malformations

    On religion and cultural policy: notes on the Roman Catholic Church

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    This paper argues that religious institutions have largely been neglected within the study of cultural policy. This is attributed to the inherently secular tendency of most modern social sciences. Despite the predominance of the ‘secularisation paradigm’, the paper notes that religion continues to promote powerful attachments and denunciations. Arguments between the ‘new atheists’, in particular, Richard Dawkins, and their opponents are discussed, as is Habermas’s conciliatory encounter with Joseph Ratzinger (later Pope Benedict XVI). The paper then moves to a consideration of the Roman Catholic Church as an agent of cultural policy, whose overriding aim is the promotion of ‘Christian consciousness’. Discussion focuses on the contested meanings of this, with reference to (1) the deliberations of Vatican II and (2) the exercise of theological and cultural authority by the Pope and the Congregation for the Doctrine of the Faith (CDF). It is argued that these doctrinal disputes intersect with secular notions of social and cultural policy and warrant attention outside the specialist realm of theological discourse

    Half-life determination of Tb-155 from mass-separated samples produced at CERN-MEDICIS

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    Terbium-155 has been identified for its potential for single-photon emission computed tomography (SPECT) in nuclear medicine. For activity measurements, an accurate and precise half-life of this radionuclide is required. However, the currently evaluated half-life of 5.32(6) d with a relative standard uncertainty of 1.1% determines the precision possible. Limited literature for the half-life measurements of this radionuclide is available and all reported investigations are prior to 1970. Further measurements are therefore needed to confirm the accuracy and improve the precision of the half-life for its use in the clinical setting. Two samples produced and mass separated at the CERN-MEDICIS facility have been measured at the National Physical Laboratory by two independent techniques: liquid scintillation counting and high-purity germanium gamma-ray spectrometry. A half-life of 5.2346(36) d has been determined from the weighted mean of the half-lives determined by the two techniques. The half-life reported in this work has shown a relative difference of 1.6% to the currently evaluated half-life and has vastly improved the precision.Peer reviewe

    Direct aerosol chemical composition measurements to evaluate the physicochemical differences between controlled sea spray aerosol generation schemes

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    Controlled laboratory studies of the physical and chemical properties of sea spray aerosol (SSA) must be under-pinned by a physically and chemically accurate representation of the bubble-mediated production of nascent SSA particles. Bubble bursting is sensitive to the physico-chemical properties of seawater. For a sample of seawater, any important differences in the SSA production mechanism are projected into the composition of the aerosol particles produced. Using direct chemical measurements of SSA at the single-particle level, this study presents an intercomparison of three laboratory-based, bubble-mediated SSA production schemes: gas forced through submerged sintered glass filters ("frits"), a pulsed plunging-waterfall apparatus, and breaking waves in a wave channel filled with natural seawater. The size-resolved chemical composition of SSA particles produced by breaking waves is more similar to particles produced by the plunging waterfall than those produced by sintered glass filters. Aerosol generated by disintegrating foam produced by sintered glass filters contained a larger fraction of organic-enriched particles and a different size-resolved elemental composition, especially in the 0.8–2 μm dry diameter range. Interestingly, chemical differences between the methods only emerged when the particles were chemically analyzed at the single-particle level as a function of size; averaging the elemental composition of all particles across all sizes masked the differences between the SSA samples. When dried, SSA generated by the sintered glass filters had the highest fraction of particles with spherical morphology compared to the more cubic structure expected for pure NaCl particles produced when the particle contains relatively little organic carbon. In addition to an intercomparison of three SSA production methods, the role of the episodic or "pulsed" nature of the waterfall method on SSA composition was under-taken. In organic-enriched seawater, the continuous operation of the plunging waterfall resulted in the accumulation of surface foam and an over-expression of organic matter in SSA particles compared to those produced by a pulsed plunging waterfall. Throughout this set of experiments, comparative differences in the SSA number size distribution were coincident with differences in aerosol particle composition, indicating that the production mechanism of SSA exerts important controls on both the physical and chemical properties of the resulting aerosol with respect to both the internal and external mixing state of particles. This study provides insight into the inextricable physicochemical differences between each of the bubble-mediated SSA generation mechanisms tested and the aerosol particles that they produce, and also serves as a guideline for future laboratory studies of SSA particles

    Attachment styles and personal growth following romantic breakups: The mediating roles of distress, rumination, and tendency to rebound

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    © 2013 Marshall et al. 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.This article has been made available through the Brunel Open Access Publishing Fund.The purpose of this research was to examine the associations of attachment anxiety and avoidance with personal growth following relationship dissolution, and to test breakup distress, rumination, and tendency to rebound with new partners as mediators of these associations. Study 1 (N = 411) and Study 2 (N = 465) measured attachment style, breakup distress, and personal growth; Study 2 additionally measured ruminative reflection, brooding, and proclivity to rebound with new partners. Structural equation modelling revealed in both studies that anxiety was indirectly associated with greater personal growth through heightened breakup distress, whereas avoidance was indirectly associated with lower personal growth through inhibited breakup distress. Study 2 further showed that the positive association of breakup distress with personal growth was accounted for by enhanced reflection and brooding, and that anxious individuals’ greater personal growth was also explained by their proclivity to rebound. These findings suggest that anxious individuals’ hyperactivated breakup distress may act as a catalyst for personal growth by promoting the cognitive processing of breakup-related thoughts and emotions, whereas avoidant individuals’ deactivated distress may inhibit personal growth by suppressing this cognitive work

    Gendering international student migration: an Indian case-study

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    Despite the mainstreaming of gender perspectives into migration research, very few attempts have been made to gender international student migration. This paper poses three questions about Indian students who study abroad. Are there gender differences in their motivations? How do they negotiate their gendered everyday lives when abroad? Is the return to India shaped by gender relations? An online survey of Indian study-abroad students (n = 157), and in-depth interviews with Indian students in Toronto (n = 22), returned students in New Delhi (n = 21), and with parents of students abroad (n = 22) help to provide answers. Conceptually, the paper draws on a ‘gendered geographies of power’ framework and on student migration as an embodied process subject to ‘matrices of (un)intelligibility’. We find minimal gender-related differences in motivations to study abroad, except that male students are drawn from a wider social background. However, whilst abroad, both male and female Indian students face challenges in performing their gendered identities. The Indian patrifocal family puts greater pressure on males to return; females face greater challenges upon return
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