767 research outputs found

    Fatiguing verbal working memory to reduce explicit hypothesis testing during skill acquisition: A new implicit motor learning paradigm?

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    How we learn novel motor skills is crucial for motor performance. Motor skills learned through implicit processes have been shown to have higher neural efficiency, lower likelihood of interference from conscious control during motor output, and more stable performance under pressure, stress, fatigue and multitasking situations (Maxwell, Masters & Eves, 2000; Steenbergen, Van Der Kamp, Verneau, Jongbloed-Pereboom & Masters, 2010; Zhu, Yeung, Poolton, Lee, Leung & Masters, 2015). These performance benefits are sought after in both clinical and sporting domains, and make implicit motor learning a viable alternative to explicit forms of learning. However, current implicit motor learning paradigms have encountered limitations that hinder their practical application (Lam, Maxwell & Masters, 2009; Zhu et al., 2015); therefore, new implicit motor learning paradigms need to be created. This thesis investigated whether cognitive fatigue can be used to encourage novices to perform a novel motor task in an implicit manner. We hypothesized that inducing cognitive fatigue in people would suppress verbal working memory activity, thereby minimising hypothesis testing about the task to be performed and causing implicit motor learning. The research was conducted on thirty-three healthy adults (women=19, men=14; mean age= 23.3±5.5) who reported limited golf experience. All participants were randomly allocated to one of two treatment conditions: control (non-fatigued) or experimental (fatigued). We analysed the differences in verbal working memory performance, motor skill performance and hypothesis testing measures between the two groups. Our results showed that participants in the experimental condition reported a significant increase in subjective feelings of fatigue following the intervention; however, this was not reflected by a decrease in working memory activity. The results also illustrated no significant differences in motor performance or hypothesis testing between the two groups. Overall, the cognitive fatigue task was shown to successfully alter self-reported levels of fatigue (VAS-f), although we speculate that the fatigue levels produced by the intervention were not sufficient to suppress working memory activity during performance of a novel motor task

    Marfan syndrome and pregnancy: maternal and neonatal outcomes

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    Objective To report outcomes in a recent series of pregnancies in women with Marfan syndrome (MFS). Design Retrospective case note review. Setting Tertiary referral unit (Chelsea and Westminster and Royal Brompton Hospitals). Sample Twenty-nine pregnancies in 21 women with MFS between 1995 and 2010. Methods Multidisciplinary review of case records. Main outcome measures Maternal and neonatal mortality and morbidity of patients with MFS and healthy controls. Results There were no maternal deaths. Significant cardiac complications occurred in five pregnancies (17%): one woman experienced a type–A aortic dissection; two women required cardiac surgery within 6 months of delivery; and a further two women developed impaired left ventricular function during the pregnancy. Women with MFS were also more likely to have obstetric complications (OR 3.29, 95% CI 1.30–8.34), the most frequent of which was postpartum haemorrhage (OR 8.46, 95% CI 2.52–28.38). There were no perinatal deaths, although babies born to mothers with MFS were delivered significantly earlier than those born to the control group (median 39 versus 40 weeks of gestation, Mann–Whitney U–test, P = 0.04). These babies were also significantly more likely to be small for gestational age (24% in the MFS group versus 6% in the controls; OR 4.95, 95% CI 1.58–15.55). Conclusions Pregnancy in women with MFS continues to be associated with significant rates of maternal, fetal, and neonatal complications. Effective pre-pregnancy counselling and meticulous surveillance during pregnancy, delivery, and the puerperium by an experienced multidisciplinary team are warranted for women with MFS

    Decreasing intensity of open-ocean convection in the Greenland and Iceland seas

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    The air–sea transfer of heat and fresh water plays a critical role in the global climate system. This is particularly true for the Greenland and Iceland seas, where these fluxes drive ocean convection that contributes to Denmark Strait overflow water, the densest component of the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). Here we show that the wintertime retreat of sea ice in the region, combined with different rates of warming for the atmosphere and sea surface of the Greenland and Iceland seas, has resulted in statistically significant reductions of approximately 20% in the magnitude of the winter air–sea heat fluxes since 1979. We also show that modes of climate variability other than the North Atlantic Oscillation (NAO) are required to fully characterize the regional air–sea interaction. Mixed-layer model simulations imply that further decreases in atmospheric forcing will exceed a threshold for the Greenland Sea whereby convection will become depth limited, reducing the ventilation of mid-depth waters in the Nordic seas. In the Iceland Sea, further reductions have the potential to decrease the supply of the densest overflow waters to the AMOC

    Dynamic CpG methylation delineates subregions within super-enhancers selectively decommissioned at the exit from naïve pluripotency

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    Clusters of enhancers, referred as to super-enhancers (SEs), control the expression of cell identity genes. The organisation of these clusters, and how they are remodelled upon developmental transitions remain poorly understood. Here, we report the existence of two types of enhancer units within SEs typified by distinctive CpG methylation dynamics in embryonic stem cells (ESCs). We find that these units are either prone for decommissioning or remain constitutively active in epiblast stem cells (EpiSCs), as further established in the peri-implantation epiblast in vivo. Mechanistically, we show a pivotal role for ESRRB in regulating the activity of ESC-specific enhancer units and propose that the developmentally regulated silencing of ESRRB triggers the selective inactivation of these units within SEs. Our study provides insights into the molecular events that follow the loss of ESRRB binding, and offers a mechanism by which the naive pluripotency transcriptional programme can be partially reset upon embryo implantation

    Overcoming barriers to engaging socio-economically disadvantaged populations in CHD primary prevention: a qualitative study

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    <p><b>Background:</b> Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD).</p> <p><b>Methods:</b> The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches.</p> <p><b>Results:</b> Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention.</p> <p><b>Conclusion:</b> Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.</p&gt

    Sabotage in Contests: A Survey

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    A contest is a situation in which individuals expend irretrievable resources to win valuable prize(s). ‘Sabotage’ is a deliberate and costly act of damaging a rival’s' likelihood of winning the contest. Sabotage can be observed in, e.g., sports, war, promotion tournaments, political or marketing campaigns. In this article, we provide a model and various perspectives on such sabotage activities and review the economics literature analyzing the act of sabotage in contests. We discuss the theories and evidence highlighting the means of sabotage, why sabotage occurs, and the effects of sabotage on individual players and on overall welfare, along with possible mechanisms to reduce sabotage. We note that most sabotage activities are aimed at the ablest player, the possibility of sabotage reduces productive effort exerted by the players, and sabotage may lessen the effectiveness of public policies, such as affirmative action, or information revelation in contests. We discuss various policies that a designer may employ to counteract sabotage activities. We conclude by pointing out some areas of future research

    Toward optimal implementation of cancer prevention and control programs in public health: A study protocol on mis-implementation

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    Abstract Background Much of the cancer burden in the USA is preventable, through application of existing knowledge. State-level funders and public health practitioners are in ideal positions to affect programs and policies related to cancer control. Mis-implementation refers to ending effective programs and policies prematurely or continuing ineffective ones. Greater attention to mis-implementation should lead to use of effective interventions and more efficient expenditure of resources, which in the long term, will lead to more positive cancer outcomes. Methods This is a three-phase study that takes a comprehensive approach, leading to the elucidation of tactics for addressing mis-implementation. Phase 1: We assess the extent to which mis-implementation is occurring among state cancer control programs in public health. This initial phase will involve a survey of 800 practitioners representing all states. The programs represented will span the full continuum of cancer control, from primary prevention to survivorship. Phase 2: Using data from phase 1 to identify organizations in which mis-implementation is particularly high or low, the team will conduct eight comparative case studies to get a richer understanding of mis-implementation and to understand contextual differences. These case studies will highlight lessons learned about mis-implementation and identify hypothesized drivers. Phase 3: Agent-based modeling will be used to identify dynamic interactions between individual capacity, organizational capacity, use of evidence, funding, and external factors driving mis-implementation. The team will then translate and disseminate findings from phases 1 to 3 to practitioners and practice-related stakeholders to support the reduction of mis-implementation. Discussion This study is innovative and significant because it will (1) be the first to refine and further develop reliable and valid measures of mis-implementation of public health programs; (2) bring together a strong, transdisciplinary team with significant expertise in practice-based research; (3) use agent-based modeling to address cancer control implementation; and (4) use a participatory, evidence-based, stakeholder-driven approach that will identify key leverage points for addressing mis-implementation among state public health programs. This research is expected to provide replicable computational simulation models that can identify leverage points and public health system dynamics to reduce mis-implementation in cancer control and may be of interest to other health areas

    Solution structure of a repeated unit of the ABA-1 nematode polyprotein allergen of ascaris reveals a novel fold and two discrete lipid-binding sites

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    Parasitic nematode worms cause serious health problems in humans and other animals. They can induce allergic-type immune responses, which can be harmful but may at the same time protect against the infections. Allergens are proteins that trigger allergic reactions and these parasites produce a type that is confined to nematodes, the nematode polyprotein allergens (NPAs). These are synthesized as large precursor proteins comprising repeating units of similar amino acid sequence that are subsequently cleaved into multiple copies of the allergen protein. NPAs bind small lipids such as fatty acids and retinol (Vitamin A) and probably transport these sensitive and insoluble compounds between the tissues of the worms. Nematodes cannot synthesize these lipids, so NPAs may also be crucial for extracting nutrients from their hosts. They may also be involved in altering immune responses by controlling the lipids by which the immune and inflammatory cells communicate. We describe the molecular structure of one unit of an NPA, the well-known ABA-1 allergen of Ascaris and find its structure to be of a type not previously found for lipid-binding proteins, and we describe the unusual sites where lipids bind within this structur

    Challenging the perceptions of cancer service provision for the disadvantaged: evaluating utilisation of cancer support services in Western Australia

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    Purpose: The main aim of the study was to evaluate the distributive utilisation of services provided by the Cancer Council of Western Australia according to age, social disadvantage and geographic location. Results were used to determine if social justice principles in terms of service provision were upheld. Methods: Cross-sectional study design to evaluate utilisation of cancer support services over a 12-week period in 2007 using administrative records. Service utilisation incidence rates (population information obtained from de-identified cancer registry data) and incidence rate ratios were calculated by gender, age group, cancer type, socioeconomic status and location. Results: The Information services (52%, n = 4,932) were the most popular Cancer Council of Western Australia (CCWA) services followed by Emotional Support services (21%, n =  2,045). All CCWA services were more likely to be accessed by those with a lower socioeconomic status, except for Clinical Services. The rate of utilisation for patients with cancer in the 65+ years age group was found to be under-serviced relative to the 40–64 years age group. Conclusions: Overall, the study has shown that CCWA services are not provided uniformly (horizontal equity) across strata of socio-economic status. Given that the prevalence of cancer generally increases with socio-economic advantage, the findings were notable in regard to one particular outcome. Results for age indicate that there may be some underlying accessibility issues for the aged population. The findings are consistent with current literature highlighting issues of disadvantage in regard to the ability of elderly persons with cancer to access services and support

    A Nomenclature for Vertebral Fossae in Sauropods and Other Saurischian Dinosaurs

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    The axial skeleton of extinct saurischian dinosaurs (i.e., theropods, sauropodomorphs), like living birds, was pneumatized by epithelial outpocketings of the respiratory system. Pneumatic signatures in the vertebral column of fossil saurischians include complex branching chambers within the bone (internal pneumaticity) and large chambers visible externally that are bounded by neural arch laminae (external pneumaticity). Although general aspects of internal pneumaticity are synapomorphic for saurischian subgroups, the individual internal pneumatic spaces cannot be homologized across species or even along the vertebral column, due to their variability and absence of topographical landmarks. External pneumatic structures, in contrast, are defined by ready topological landmarks (vertebral laminae), but no consistent nomenclatural system exists. This deficiency has fostered confusion and limited their use as character data in phylogenetic analysis.We present a simple system for naming external neural arch fossae that parallels the one developed for the vertebral laminae that bound them. The nomenclatural system identifies fossae by pointing to reference landmarks (e.g., neural spine, centrum, costal articulations, zygapophyses). We standardize the naming process by creating tripartite names from “primary landmarks,” which form the zygodiapophyseal table, “secondary landmarks,” which orient with respect to that table, and “tertiary landmarks,” which further delineate a given fossa.The proposed nomenclatural system for lamina-bounded fossae adds clarity to descriptions of complex vertebrae and allows these structures to be sourced as character data for phylogenetic analyses. These anatomical terms denote potentially homologous pneumatic structures within Saurischia, but they could be applied to any vertebrate with vertebral laminae that enclose spaces, regardless of their developmental origin or phylogenetic distribution
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