2,421 research outputs found

    Multilevel correlates of household anthropometric typologies in Colombian mothers and their infants

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    Background. The aim of this study was to establish the association of maternal, family, and contextual correlates of anthropometric typologies at the household level in Colombia using 2005 Demographic Health Survey (DHS/ENDS) data.Methods. Household-level information from mothers 18-49 years old and their children less than 5 years old was included. Stunting and overweight were assessed for each child. Mothers were classified according to their body mass index. Four anthropometric typologies at the household level were constructed: normal, underweight, overweight, and dual burden. Four three-level [households (n = 8598) nested within municipalities (n = 226), nested within states (n = 32)] hierarchical polytomous logistic models were developed. Household log-odds of belonging to one of the four anthropometric categories, holding 'normal' as the reference group, were obtained.Results. This study found that anthropometric typologies were associated with maternal and family characteristics of maternal age, parity, maternal education, and wealth index. Higher municipal living conditions index was associated with a lower likelihood of underweight typology and a higher likelihood of overweight typology. Higher population density was associated with a lower likelihood of overweight typology.Conclusion. Distal and proximal determinants of the various anthropometric typologies at the household level should be taken into account when framing policies and designing interventions to reduce malnutrition in Colombia. Copyright © The Author(s) 2018

    Effect of gaseous and solid simulated jet plumes on an 040A space shuttle launch configuration at m=1.6 to 2.2

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    The effect of plume-induced flow separation and aspiration effects due to operation of both orbiter and the solid rocket motors on a 0.019-scale model of the launch configuration of the Space Shuttle Vehicle is determined. Longitudinal and lateral-directional stability data were obtained at Mach numbers of 1.6, 2.0, and 2.2 with and without the engines operating. The plumes exiting from the engines were simulated by a cold-gas jet supplied by an auxiliary 200-atm air supply system and solid-body plume simulators. The aerodynamic effects produced by these two simulation procedures are compared. The parameters most significantly affected by the jet plumes are pitching moment, elevon control effectiveness, axial force, and orbiter wing loads. The solid rocket motor (SRM) plumes have the largest effect on the aerodynamic characteristics. The effect of the orbiter plumes in combination with the SRM plumes is also significant. Variations in the nozzle design parameters and configuration changes can reduce the jet plume-induced aerodynamic effects

    Graphene Electrochemistry: Fundamentals through to Electroanalytical Applications

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    Graphene is reported to possess a range of unique and highly desired properties and consequently has potential to revolutionise the field of electrochemistry if diligently employed as a new-generation electrode material. Graphene potentially represents the world’s thinnest electrode material, but there are experimental parameters to be overcome: the first problem is how to electrically wire/connect to the graphene sample(s) as to obtain the reported benefits; the second issue is how to reduce aggregation of graphene sheets back to their lowest energy conformation, that is, graphite, due to the strong π–π interactions between the graphene sheets; the third and final limitation is that various fabrication routes produce graphene to differing qualities, a factor that must be considered when exploring its fundamental electrochemical properties and electroanalytical implementation. This thesis reports on the fundamental electrochemical characterisation and resultant electroanalytical applicability of utilising graphene as a novel electrode material. The thesis consists of four key contributions, each developing on the knowledge gained from the previous. Chapters 1 through to 3 give an overview of the relevant fundamental electrochemical concepts with which this thesis is concerned. Chapter 4 provides a ‘snap-shot’ of the state of the graphene literature from 2010 (upon the commencement of this work), from which successive chapters follow the chronological development and investigation of graphene as produced through a variety of synthesis methods, gradually building a complete picture and understanding of the electrochemistry of graphene and the implications of its properties towards the fabrication and implementation of graphene as an electroanalytical sensor substrate. IV | P a g e Chapter 5 details the relevant experimental information and the full physicochemical characterisation of the various graphene materials utilised within this work. Chapters 6 and 7 utilise graphenes that are fabricated via a ‘top-down’ approach, which is most commonly employed in the literature, where in order to ‘connect to’ the graphene a liquid suspension is immobilised onto a suitable electrode surface. Chapter 6 uses surfactant-modified graphene and investigates, for the first time, the influence that such surfactants have on the observed electrochemistry. Chapter 7 uses pristine graphene in solution and considers; the aspects of various ‘coverages’ of graphene, the supporting electrode substrate, and how the formation of few and multiple layered graphene structures can influence the observed response. These parameters are overlooked within the current literature. Chapter 8 utilises graphene that is fabricated via a ‘bottom-up’ Chemical Vapour Deposition approach, which gives rise to high quality single layer graphene domains that, once efficiently ‘housed’ in order to connect to the graphene, allow the electrochemical exploration of monolayer graphene to be realised and be compared to quasi-graphene and defect abundant graphene structures for the first time. This approach allows the structure of graphene to be correlated with that of the electrochemical response for the first time. Critically, this work unambiguously demonstrates that the electrochemical response is edge plane like defect dependent. The final part of this thesis (Chapter 9) utilises a range of modified graphenes including novel three-dimensional (3D) structures (a graphene foam and graphene paste) and functionalised graphene (graphene/graphitic oxide), with the effects of said modifications explored towards the fundamental electrochemical and electroanalytical properties obtained. The first part of this chapter reports the electrochemistry of a novel freestanding 3D graphene V | P a g e foam and, for the first time, critically compares this to a freestanding 3D carbon foam alternative. It is demonstrated that the graphene foam gives rise to beneficial voltammetric responses in non-aqueous media, namely ionic liquids. This chapter also explores the use of a graphene paste electrode and demonstrates that the voltammetric response is no better than that of a graphite based paste electrode. Last, the use of graphene/graphitic oxide as an electrode material is explored and shown to give rise to unique voltammetric signatures, which are coverage dependant and can be utilised as a means of characterising the successful production of graphene through the reduction of graphene/graphitic oxide (as commonly utilised within the current electrochemical literature). Furthermore, it is shown that the unique voltammetry observed at graphene/graphitic oxide modified electrodes can be used beneficially for electrocatalytic processes. This thesis demonstrates that, within the graphene electrochemical literature, control experiments are often an overlooked comparison, which are needed for the electrochemical response of graphene to be understood and before the benefits of graphene can be claimed in such instances where superiority is ‘demonstrated’

    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

    Long-term evaluation of a course on evidence-based public health in the U.S. and Europe

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    The evidence-based public health course equips public health professionals with skills and tools for applying evidence-based frameworks and processes in public health practice. To date, training has included participants from all the 50 U.S. states, 2 U.S. territories, and multiple other countries besides the U.S. This study pooled follow-up efforts (5 surveys, with 723 course participants, 2005-2019) to explore the benefits, application, and barriers to applying the evidence-based public health course content. All analyses were completed in 2020. The most common benefits (reported by \u3e80% of all participants) were identifying ways to apply knowledge in their work, acquiring new knowledge, and becoming a better leader who promotes evidence-based approaches. Participants most frequently applied course content to searching the scientific literature (72.9%) and least frequently to writing grants (42.7%). Lack of funds for continued training (35.3%), not having enough time to implement evidence-based public health approaches (33.8%), and not having coworkers trained in evidence-based public health (33.1%) were common barriers to applying the content from the course. Mean scores were calculated for benefits, application, and barriers to explore subgroup differences. European participants generally reported higher benefits from the course (mean difference=0.12, 95% CI=0.00, 0.23) and higher frequency of application of the course content to their job (mean difference=0.17, 95% CI=0.06, 0.28) than U.S. participants. Participants from later cohorts (2012-2019) reported more overall barriers to applying course content in their work (mean difference=0.15, 95% CI=0.05, 0.24). The evidence-based public health course represents an important strategy for increasing the capacity (individual skills) for evidence-based processes within public health practice. Organization-level methods are also needed to scale up and sustain capacity-building efforts

    Evaluating a train-the-trainer approach for improving capacity for evidence-based decision making in public health

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    BACKGROUND: Evidence-based public health gives public health practitioners the tools they need to make choices based on the best and most current evidence. An evidence-based public health training course developed in 1997 by the Prevention Research Center in St. Louis has been taught by a transdisciplinary team multiple times with positive results. In order to scale up evidence-based practices, a train-the-trainer initiative was launched in 2010. METHODS: This study examines the outcomes achieved among participants of courses led by trained state-level faculty. Participants from trainee-led courses in four states (Indiana, Colorado, Nebraska, and Kansas) over three years were asked to complete an online survey. Attempts were made to contact 317 past participants. One-hundred forty-four (50.9 %) reachable participants were included in analysis. Outcomes measured include frequency of use of materials, resources, and other skills or tools from the course; reasons for not using the materials and resources; and benefits from attending the course. Survey responses were tabulated and compared using Chi-square tests. RESULTS: Among the most commonly reported benefits, 88 % of respondents agreed that they acquired knowledge about a new subject, 85 % saw applications for the knowledge to their work, and 78 % agreed the course also improved abilities to make scientifically informed decisions at work. The most commonly reported reasons for not using course content as much as intended included not having enough time to implement evidence-based approaches (42 %); other staff/peers lack training (34 %); and not enough funding for continued training (34 %). The study findings suggest that utilization of course materials and teachings remains relatively high across practitioner groups, whether they were taught by the original trainers or by state-based trainers. CONCLUSIONS: The findings of this study suggest that train-the-trainer is an effective method for broadly disseminating evidence-based public health principles. Train-the-trainer is less costly than the traditional method and allows for courses to be tailored to local issues, thus making it a viable approach to dissemination and scale up of new public health practices. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12913-015-1224-2) contains supplementary material, which is available to authorized users

    Multilevel correlates of household anthropometric typologies in Colombian mothers and their infants

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    Background. The aim of this study was to establish the association of maternal, family, and contextual correlates of anthropometric typologies at the household level in Colombia using 2005 Demographic Health Survey (DHS/ENDS) data.Methods. Household-level information from mothers 18-49 years old and their children less than 5 years old was included. Stunting and overweight were assessed for each child. Mothers were classified according to their body mass index. Four anthropometric typologies at the household level were constructed: normal, underweight, overweight, and dual burden. Four three-level [households (n = 8598) nested within municipalities (n = 226), nested within states (n = 32)] hierarchical polytomous logistic models were developed. Household log-odds of belonging to one of the four anthropometric categories, holding 'normal' as the reference group, were obtained.Results. This study found that anthropometric typologies were associated with maternal and family characteristics of maternal age, parity, maternal education, and wealth index. Higher municipal living conditions index was associated with a lower likelihood of underweight typology and a higher likelihood of overweight typology. Higher population density was associated with a lower likelihood of overweight typology.Conclusion. Distal and proximal determinants of the various anthropometric typologies at the household level should be taken into account when framing policies and designing interventions to reduce malnutrition in Colombia. Copyright © The Author(s) 2018

    Analysis of the results of the Washington County District 15 elementary school vision screening program: The Abbo study (volume II)

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    Analysis of the results of the Washington County District 15 elementary school vision screening program: The Abbo study (volume II

    Analysis of the results of the Washington County District 15 elementary school vision screening program: The Abbo study (volume I)

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    Analysis of the results of the Washington County District 15 elementary school vision screening program: The Abbo study (volume I
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