366 research outputs found
An hp-adaptive discontinuous Galerkin method for phase field fracture
The phase field method is becoming the de facto choice for the numerical analysis of complex problems that involve multiple initiating, propagating, interacting, branching and merging fractures. However, within the context of finite element modelling, the method requires a fine mesh in regions where fractures will propagate, in order to capture sharp variations in the phase field representing the fractured/damaged regions. This means that the method can become computationally expensive when the fracture propagation paths are not known a priori. This paper presents a 2D -adaptive discontinuous Galerkin finite element method for phase field fracture that includes a posteriori error estimators for both the elasticity and phase field equations, which drive mesh adaptivity for static and propagating fractures. This combination means that it is possible to be reliably and efficiently solve phase field fracture problems with arbitrary initial meshes, irrespective of the initial geometry or loading conditions. This ability is demonstrated on several example problems, which are solved using a light-BFGS (Broyden–Fletcher–Goldfarb–Shanno) quasi-Newton algorithm. The examples highlight the importance of driving mesh adaptivity using both the elasticity and phase field errors for physically meaningful, yet computationally tractable, results. They also reveal the importance of including -refinement, which is typically not included in existing phase field literature. The above features provide a powerful and general tool for modelling fracture propagation with controlled errors and degree-of-freedom optimised meshes
An Innovative Approach for Community Engagement: Using an Audience Response System
Community-based participatory research methods allow for community engagement in the effort to reduce cancer health disparities. Community engagement involves health professionals becoming a part of the community in order to build trust, learn from the community and empower them to reduce disparities through their own initiatives and ideas. Audience Response Systems (ARS) are an innovative and engaging way to involve the community and obtain data for research purposes using keypads to report results via power point. The use of ARS within communities is very limited and serves to widen the disparity gap by not delivering new advances in medical knowledge and technology among all population groups. ARS was implemented at a community town hall event sponsored by a National Institute on Minority Health and Health Disparities Exploratory Center of Excellence, the Center for Equal Health. Participants appreciated being able to see how everyone else answered and felt included in the research process. ARS is beneficial because the community can answer truthfully and provides instant research results. Additionally, researchers can collect large amounts of data quickly, in a non-threatening way while tracking individual responses anonymously. Audience Response Systems proved to be an effective tool for successfully accomplishing community-based participatory research
Johnston Atoll: reef fish hybrid zone between Hawaii and the equatorial Pacific
Johnston Atoll is isolated in the Central Pacific Ocean (16°45′ N 169°31′ W) about 1287 km (800 miles) southwest of Honolulu, Hawaii and 1440 km (900 miles) north of the equatorial Line Islands, Kiribati. The labrid species, Thalassoma lutescens, has a wide range of distribution in the equatorial Pacific. The related species, Thalassoma duperrey, is endemic to the Hawaiian Islands. The pelagic larvae of both species dispersed to Johnston Atoll, where we found a mix of adult phenotypes representing a range of hybridization events over generations. A hybrid acanthurid was also documented. In addition, the arrival and colonization of two pomacentrid (damselfish) species to the atoll was observed in 1999. These pomacentrid sister-species, Abudefduf abdominalis and A. vaigiensis, have become established populations with subsequent hybridization. The biogeography of the Johnston Atoll coral reef fish population shows some degree of local population retention. It is also evident that this biogeographic isolation is periodically compromised by large ocean current oscillations in the equatorial and central Pacific Ocean that bring larval fishes from either Hawaii or the Line Islands, and may distribute Johnston Atoll originating larvae elsewhere as well. The reef fauna and oceanography of this atoll provides the circumstances for improving scientific insight into marine fish speciation and island biogeography.Published versio
"Getting sicker quicker": does living in a more deprived neighbourhood mean your health deteriorates faster?
Data from the longitudinal West of Scotland Twenty-07 Study: Health in the Community was used to examine whether, over a 20 year period, the self-reported health of people living in deprived areas became poorer faster compared to those living in more affluent areas. Three cohorts (born in the early 1930s, 1950s and 1970s) are included, covering 60 years of the life span. Using multilevel growth curve models, a 40% probability of reporting poor health was predicted among residents of more deprived areas at an earlier age (66) compared to those living in more affluent areas (83). Wider area differences were seen for men than for women. Our findings indicate that attempts to reduce area differences in health should start young but also continue throughout the lifespan
Age moderates the link between epilepsy and Self-rated Health (SRH)
Epilepsy is one of the most severe neurological diseases that affect people around the globe. Self-rated health (SRH) refers to one’s subjective evaluation of their own health and is associated with various outcomes such as morbidity and mortality. Thus, understanding the association between epilepsy and SRH is of great importance. Moreover, SRH generally decreases with age. The aim of the current study is to test whether age moderates the link between epilepsy and SRH. The current study used a hierarchical regression and three multiple regressions to analyze the associations between epilepsy and SRH in 529 epilepsy patients and 46,978 healthy controls from the United Kingdom. The current study found that age significantly moderates the association between epilepsy and SRH. Specifically, epilepsy status was negatively related to SRH in young people (b = −0.69, p < 0.001, 95% C.I. [−0.84, −0.54]), more strongly in middle-aged adults (b = −0.81, p < 0.001, 95% C.I. [−0.95, −0.66]), and most strongly in older adults (b = −0.89, p < 0.001, 95% C.I. [−1.09, −0.69]). The current study may imply that older adults need more attention in terms of their SRH, which is closely associated with outcomes. Clinicians and health professionals should come up with ways that improve SRH in people with epilepsy, especially for older adults with epilepsy
The drugs don't sell: DIY heart health and the over-the-counter statin experience
This paper draws on a study of over-the-counter statins to provide a critical account of the figure of the ‘pharmaceutical consumer’ as a key actor in the pharmaceuticalisation literature. A low dose statin, promising to reduce cardiovascular risk, was reclassified to allow sale in pharmacies in the UK in 2004. We analysed professional and policy debates about the new product, promotional and sales information, and interviews with consumers and potential consumers conducted between 2008 and 2011, to consider the different consumer identities invoked by these diverse actors.
While policymakers constructed an image of ‘the citizen-consumer’ who would take responsibility for heart health through exercising the choice to purchase a drug that was effectively rationed on the NHS and medical professionals raised concerns about ‘a flawed consumer’ who was likely to misuse the product, both these groups assumed that there would be a market for the drug. By contrast, those who bought the product or potentially fell within its target market might appear as ‘health consumers’, seeking out and paying for different food and lifestyle products and services, including those targeting high cholesterol. However, they were reluctant ‘pharmaceutical consumers’ who either preferred to take medication on the advice of a doctor, or sought to minimize medicine use.
In comparison to previous studies, our analysis builds understanding of individual consumers in a market, rather than collective action for access to drugs (or, less commonly, compensation for adverse effects). Where some theories of pharmaceuticalisation have presented consumers as creating pressure for expanding markets, our data suggests that sociologists should be cautious about assuming there will be demand for new pharmaceutical products, especially those aimed at prevention or asymptomatic conditions, even in burgeoning health markets
Early-Life Air Pollution Exposure, Neighborhood Poverty, and Childhood Asthma in the United States, 1990⁻2014.
Ambient air pollution is a well-known risk factor of various asthma-related outcomes, however, past research has often focused on acute exacerbations rather than asthma development. This study draws on a population-based, multigenerational panel dataset from the United States to assess the association of childhood asthma risk with census block-level, annual-average air pollution exposure measured during the prenatal and early postnatal periods, as well as effect modification by neighborhood poverty. Findings suggest that early-life exposures to nitrogen dioxide (NO₂), a marker of traffic-related pollution, and fine particulate matter (PM2.5), a mixture of industrial and other pollutants, are positively associated with subsequent childhood asthma diagnosis (OR = 1.25, 95% CI = 1.10⁻1.41 and OR = 1.25, 95% CI = 1.06⁻1.46, respectively, per interquartile range (IQR) increase in each pollutant (NO₂ IQR = 8.51 ppb and PM2.5 IQR = 4.43 µ/m³)). These effects are modified by early-life neighborhood poverty exposure, with no or weaker effects in moderate- and low- (versus high-) poverty areas. This work underscores the importance of a holistic, developmental approach to elucidating the interplay of social and environmental contexts that may create conditions for racial-ethnic and socioeconomic disparities in childhood asthma risk
The social course of fibromyalgia: resisting processes of marginalisation
This sociological article reports an empirical study into the lived experience of fibromyalgia. It includes 28 participants (26 women, 2 men) with a formal diagnosis of fibromyalgia. Data collection consisted of the completion of an identity box project and subsequent interviews. Data analysis followed the principles of iterative, inductive, semantic thematic analysis, and led to the identification of four major themes: the role of the social in making sense of the experience, the process of redefining lifegoals, the refusal to accept fibromyalgia as a diagnosis, and the consideration of identifying as a patient. These themes in turn demonstrate four forms of resistance against processes of marginalisation amongst those who have been diagnosed with fibromyalgia: (1) the incorporation of societal expectations and norms into their life-stories; (2) the re-making the lifeworld at a cerebral level through redefining reality and creating a new, socially acceptable reality; (3) the active rejection of the fibromyalgia diagnosis; and (4) the employment of active and pro-active countermeasures to assuming the sick role
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