3,472 research outputs found

    Geomorphologic controls on the age of particulate organic carbon from small mountainous and upland rivers

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    To assess the role that erosion processes play in governing the character of particulate organic carbon (POC) discharged from small mountainous and upland rivers, a suite of watersheds from Oregon, California, and New Zealand was investigated. The rivers share similar geology, tectonic setting, and climate, but have sediment yields that range over 3 orders of magnitude. The (14)C age of the POC loads is highly correlated with sediment yield. Carbon isotope mass balances reveal that the rivers carry bimodal mixtures of modern-plant-and ancient-rock-derived OC. At lower yields, modern plant OC dominates the material delivered to the river by sheetwash and shallow landsliding. With increasing yield, a progressively larger part of the POC is contributed directly from bedrock erosion via deep gully incision. Our results support the inference that active margin watersheds are important sources of aged POC to the ocean

    A component-based middleware framework for configurable and reconfigurable Grid computing

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    Significant progress has been made in the design and development of Grid middleware which, in its present form, is founded on Web services technologies. However, we argue that present-day Grid middleware is severely limited in supporting projected next-generation applications which will involve pervasive and heterogeneous networked infrastructures, and advanced services such as collaborative distributed visualization. In this paper we discuss a new Grid middleware framework that features (i) support for advanced network services based on the novel concept of pluggable overlay networks, (ii) an architectural framework for constructing bespoke Grid middleware platforms in terms of 'middleware domains' such as extensible interaction types and resource discovery. We believe that such features will become increasingly essential with the emergence of next-generation e-Science applications. Copyright (c) 2005 John Wiley & Sons, Ltd

    Integrating maternal and children's oral health promotion into nursing and midwifery practice- a systematic review

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    Background Globally, oral diseases contribute to major disease problems and oral health disparities persistently exist amongst vulnerable population groups. Two contributory factors to these challenges are the shortage of dental practitioners and the characteristic separation between the medical and dental professions. Nurses and midwives, in particular, are in a potentially excellent position to assist in basic oral health services such as dental health education and intraoral screening. We aimed to assess the effectiveness of integrating promotion of oral health of young children and their mothers into nursing and midwifery practice. Methods and Findings Seven electronic databases including CENTRAL, EMBASE, MEDLINE, GLOBAL HEALTH, CINHAL, Scopus, and Web of Science were systematically searched whereas conference proceedings and theses were retrieved via PROQUEST. Only randomized, non-randomized trials and observational studies on preventive oral health programs delivered by nurses or midwives in healthcare settings or through home visits were included. Two investigators reviewed full-text articles independently to decide on eligibility for inclusion. Quality assessment was done using Cochrane tool for risk of bias for randomized trials and Downs and Black assessment tool for all other studies. Out of 3162 retrieved records, twenty one trials on oral health interventions incorporated into standard nursing practice were reviewed. Eighteen programs reported significant positive outcomes including reduction in caries experience, better oral hygiene and dietary habits and increased rates of dental visits amongst young children as reported by their caregivers. Conclusions Incorporating oral health promotion into nursing practice is a promising initiative for reducing oral health disparities by contributing to a downward trend in caries experience and increased access to dental care especially amongst the poor disadvantaged communities

    Daleel:simplifying cloud instance selection using machine learning

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    Decision making in cloud environments is quite challenging due to the diversity in service offerings and pricing models, especially considering that the cloud market is an incredibly fast moving one. In addition, there are no hard and fast rules; each customer has a specific set of constraints (e.g. budget) and application requirements (e.g. minimum computational resources). Machine learning can help address some of the complicated decisions by carrying out customer-specific analytics to determine the most suitable instance type(s) and the most opportune time for starting or migrating instances. We employ machine learning techniques to develop an adaptive deployment policy, providing an optimal match between the customer demands and the available cloud service offerings. We provide an experimental study based on extensive set of job executions over a major public cloud infrastructure

    Differing roles of autophagy in HIV-associated neurocognitive impairment and encephalitis with implications for morphine co-exposure

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    We investigated the role of autophagy in HIV-infected subjects with neurocognitive impairment (NCI) ± HIV encephalitis (HIVE), many of which had a history of polysubstance abuse/dependence, using post-mortem brain tissues to determine whether differences in autophagy related factors may be more associated with NCI or NCI-encephalitis. Using qRT-PCR, we detected significant differences in gene expression levels with SQSTM1, LAMP1 higher in HIV-infected subjects without NCI while ATG5, SQSTM1 were then lower in HIV infection/NCI and ATG7, SQSTM1 being higher in NCI-HIVE. Immunohistochemical labeling of these autophagy associated proteins (also including Beclin 1 and LC3B) in Iba1-positive microglial cells showed generally higher immunoreactivity in the NCI and NCI-HIVE groups with more focal vs. diffuse patterns of expression in the NCI-HIVE group. Furthermore, analysis of microarray data from these same subjects found significantly higher levels of LAMP1 in NCI-HIVE compared to uninfected subjects in the basal ganglia. Finally, we tested the effect of supernatant from HIV-1-infected microglia and HIV-1 Tat protein in combination with morphine on neurons in vitro and found opposing events with both significant inhibition of autophagic flux and reduced dendrite length for morphine and supernatant treatment while Tat and morphine exposure resulted in lower autophagic activity at an earlier time point and higher levels in the later. These results suggest autophagy genes and their corresponding proteins may be differentially regulated at the transcriptional, translational, and post-translational levels in the brain during various stages of the HIV disease and that infected individuals exposed to morphine can experience mixed signaling of autophagic activity which could lead to more severe NCI than those without opioid use

    Knowledge, attitudes, and practices associated with vitamin D supplementation: A cross-sectional online community survey of adults in the UK

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    OBJECTIVE: Assess knowledge, attitudes, and practices (KAPs) of a diverse population. Identify barriers and facilitators that inform routine vitamin D supplementation and self-care in the community setting. DESIGN: Cross-sectional online voluntary survey. Electronic survey link published on college Qualtrics platform and advertised widely. Study information provided with Participant Information Sheet. SETTING AND PARTICIPANTS: 556 community dwelling adults across the UK. METHODS: The overarching study included two phases, incorporating quantitative and qualitative methodologies. This paper reports findings from the first phase of the FABCOM-D (Facilitators and Barriers to Community (Healthy) Vitamin D status) study. Online survey questions were iteratively developed after background literature searches and piloted to ensure clarity and ease of understanding. Survey responses summarised using frequencies and percentages, and univariable and multivariable logistic regression models explored for any association. A p-value less than 0.05 was considered statistically significant. The Checklist for Reporting Results of Internet E-Surveys guided reporting. Statistical analysis performed using IBM SPSS software. MAIN OUTCOME MEASURES: Awareness of vitamin D information sources, health benefits and testing. Attitudes to supplementation, sun exposure and fortification. RESULTS: Three quarters of the community had some awareness of vitamin D and around half were taking supplements. The two most trusted sources of information included health professionals and the NHS website. Participants were willing to pay for supplements, supporting a self-care agenda. With increasing age, there was significant reduced intake of vitamin D supplements. This aspect needs to be explored further as this could be a concern in deficiency status in the elderly. There was acceptance of food fortification but uncertainty on how to balance food intake with supplementation. CONCLUSION: We were successful in eliciting views on KAPs around vitamin D from a community population including a large proportion of Black and Minority Ethnic individuals. The community wanted information and guidance to help manage individual vitamin D status, especially for high-risk groups, and on balancing supplementation, food fortification and sun exposure

    In the beginning: Role of autonomy support on the motivation, mental health and intentions of participants entering an exercise referral scheme

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    Self-determination theory (Deci & Ryan, 2000, Intrinsic motivation and self-determination in human behaviour. New York: Plenum Publishing) highlights the impact autonomy supportive environments can have on exercise motivation and positive health outcomes. Yet little is known about whether differential effects occur as a function of which significant other is providing this support. Further, no research has examined the relationship between motivation and the social environment with participants’ mental health and intentions to be physically active before entering an exercise intervention. Study participants were 347 British adults who were about to start an exercise referral scheme. Regression analyses revealed that the effects of autonomy support on mental health and physical activity intentions differed as a function of who provided the support (offspring, partner or physician), with the offspring having the weakest effects. A structural model was supported, indicating that autonomy support and more autonomous regulations led to more positive mental health outcomes and stronger intentions to be physically active. Knowledge of the social environmental and personal motivation of those about to commence an exercise programme can provide important insights for professionals supporting such efforts

    Process evaluation of the Bristol girls dance project

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    Background: The Bristol Girls Dance Project was a cluster randomised controlled trial that aimed to increase objectively measured moderate-to-vigorous physical activity (MVPA) levels of Year 7 (age 11–12) girls through a dance-based after-school intervention. The intervention was delivered in nine schools and consisted of up to forty after-school dance sessions. This paper reports on the main findings from the detailed process evaluation that was conducted. / Methods: Quantitative and qualitative data were collected from intervention schools. Dose and fidelity were reported by dance instructors at every session. Intervention dose was defined as attending two thirds of sessions and was measured by attendance registers. Fidelity to the intervention manual was reported by dance instructors. On four randomly-selected occasions, participants reported their perceived level of exertion and enjoyment. Reasons for non-attendance were self-reported at the end of the intervention. Semi-structured interviews were conducted with all dance instructors who delivered the intervention (n = 10) and school contacts (n = 9) in intervention schools. A focus group was conducted with girls who participated in each intervention school (n = 9). / Results: The study did not affect girls’ MVPA. An average of 31.7 girls participated in each school, with 9.1 per school receiving the intervention dose. Mean attendance and instructors’ fidelity to the intervention manual decreased over time. The decline in attendance was largely attributed to extraneous factors common to after-school activities. Qualitative data suggest that the training and intervention manual were helpful to most instructors. Participant ratings of session enjoyment were high but perceived exertion was low, however, girls found parts of the intervention challenging. / Conclusions: The intervention was enjoyed by participants. Attendance at the intervention sessions was low but typical of after-school activities. Participants reported that the intervention brought about numerous health and social benefits and improved their dance-based knowledge and skills. The intervention could be improved by reducing the number of girls allowed to participate in each school and providing longer and more in-depth training to those delivering the intervention. / Trial registration: ISRCTN52882523 Registered 25th April 2013

    Using self-determination theory to promote adolescent girls' physical activity: Exploring the theoretical fidelity of the Bristol Girls Dance Project

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    OBJECTIVES: To report the theory-based process evaluation of the Bristol Girls' Dance Project, a cluster-randomised controlled trial to increase adolescent girls' physical activity. DESIGN: A mixed-method process evaluation of the intervention's self-determination theory components comprising lesson observations, post-intervention interviews and focus groups. METHOD: Four intervention dance lessons per dance instructor were observed, audio recorded and rated to estimate the use of need-supportive teaching strategies. Intervention participants (n = 281) reported their dance instructors' provision of autonomy-support. Semi-structured interviews with the dance instructors (n = 10) explored fidelity to the theory and focus groups were conducted with participants (n = 59) in each school to explore their receipt of the intervention and views on the dance instructors' motivating style. RESULTS: Although instructors accepted the theory-based approach, intervention fidelity was variable. Relatedness support was the most commonly observed need-supportive teaching behaviour, provision of structure was moderate and autonomy-support was comparatively low. The qualitative findings identified how instructors supported competence and developed trusting relationships with participants. Fidelity was challenged where autonomy provision was limited to option choices rather than input into the pace or direction of lessons and where controlling teaching styles were adopted, often to manage disruptive behaviour. CONCLUSION: The successes and challenges to achieving theoretical fidelity in the Bristol Girls' Dance Project may help explain the intervention effects and can more broadly inform the design of theory-based complex interventions aimed at increasing young people's physical activity in after-school settings
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