1,070 research outputs found
Electrical power production from low-grade waste heat using a thermally regenerative ethylenediamine battery
Thermally regenerative ammonia-based batteries (TRABs) have been developed to harvest low-grade
waste heat as electricity. To improve the power production and anodic coulombic efficiency, the use
of ethylenediamine as an alternative ligand to ammonia was explored here. The power density of the
ethylenediamine-based battery (TRENB) was 85 \ub1 3 W m2-electrode area with 2 M ethylenediamine,
and 119 \ub14Wm2 with 3 M ethylenediamine. This power density was 68% higher than that of TRAB. The
energy density was 478 Wh m3-anolyte, which was ~50% higher than that produced by TRAB. The
anodic coulombic efficiency of the TRENB was 77 \ub1 2%, which was more than twice that obtained using
ammonia in a TRAB (35%). The higher anodic efficiency reduced the difference between the anode
dissolution and cathode deposition rates, resulting in a process more suitable for closed loop operation.
The thermal-electric efficiency based on ethylenediamine separation using waste heat was estimated to
be 0.52%, which was lower than that of TRAB (0.86%), mainly due to the more complex separation
process. However, this energy recovery could likely be improved through optimization of the ethylenediamine
separation process
Influences on diet and physical activity choices of 11–13-year-olds in a school setting
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.Objective:
This paper uses a qualitative approach to explore the factors that influence diet and physical activity choices of 11–13-year-olds with a particular focus on the impact of the school environment.
Design:
Qualitative focus groups.
Setting:
Three purposively sampled secondary schools in Devon, UK.
Method:
A total of 53 students, aged 11–13, took part in six focus groups. Thematic, framework analysis was used to analyse the data.
Result:
Four overarching themes emerged: (1) health now and in the future; (2) the role of others; (3) provision, temptation and addiction; and (4) boundaries, strategies and support. Participants demonstrated good knowledge of what constitutes a healthy lifestyle and its importance for future health, although it was not necessarily seen as a priority at this stage of life. Key influences on their choices were their peers and family, although participants also identified that the school environment influences the food choices they make while there.
Conclusion:
In this study, 11–13-year-olds identified that schools could do more to support them to make healthier food choices. However, future research needs to understand the constraints schools face in terms of food provision in order to highlight possible opportunities for intervention.All Saints Educational TrustNational Institute for Health research (NIHR
Systematic review and meta-analysis of the association between childhood overweight and obesity and primary school diet and physical activity policies.
Open Access ArticleObesity is a major public health concern and there are increasing calls for policy intervention. As obesity and the related health conditions develop during childhood, schools are being seen as important locations for obesity prevention, including multifaceted interventions incorporating policy elements. The objective of this systematic review was to evaluate the effects of policies related to diet and physical activity in schools, either alone, or as part of an intervention programme on the weight status of children aged 4 to 11 years. A comprehensive and systematic search of medical, education, exercise science, and social science databases identified 21 studies which met the inclusion criteria. There were no date, location or language restrictions. The identified studies evaluated a range of either, or both, diet and physical activity related policies, or intervention programmes including such policies, using a variety of observational and experimental designs. The policies were clustered into those which sought to affect diet, those which sought to affect physical activity and those which sought to affect both diet and physical activity to undertake random effects meta-analysis. Within the diet cluster, studies of the United States of America National School Lunch and School Breakfast Programs were analysed separately; however there was significant heterogeneity in the pooled results. The pooled effects of the physical activity, and other diet related policies on BMI-SDS were non-significant. The multifaceted interventions tended to include policy elements related to both diet and physical activity (combined cluster), and although these interventions were too varied to pool their results, significant reductions in weight-related outcomes were demonstrated. The evidence from this review suggests that, when implemented alone, school diet and physical activity related policies appear insufficient to prevent or treat overweight or obesity in children, however, they do appear to have an effect when developed and implemented as part of a more extensive intervention programme. Additional evidence is required before recommendations regarding the focus of policies can be made and therefore, increased effort should be made to evaluate the effect of policies and policy containing intervention programmes upon weight status.Medical Research Council (MRC)National Institute for Health Research (NIHR
Implementing a set of health promoting processes in English secondary schools: A comparative case study
This is the final version. Available on open access from Elsevier via the DOI in this recordObjective
To understand the enablers and barriers to implementing a set of adaptive processes aimed at supporting secondary schools to reflect on and subsequently address how they could adjust school practices, culture and the environment to create a whole school approach to promoting healthy lifestyles.
Study design
A qualitative, comparative case study.
Methods
Two in depth case studies were created of two purposefully selected schools in low socio-economic areas of South West England. Data were collected via meetings, observations, field notes, interviews and audit. Interviews were transcribed verbatim. Individual thematic analyses were conducted for each school and a comparative analysis approach was used to understand the barriers and enablers across both cases.
Results
Schools were supported to use a health-promoting lens and identify feasible improvements through an adaptive and context specific process. The school environment and ethos were identified as the areas where schools could conceive the most adjustments to enhance the promotion of healthy lifestyle choices. With the lack of government policy for health promotion in schools (HPS), the Head teacher's approach to health was key to making meaningful changes.
Conclusions
Health promoting school approaches need to be adaptive to local context, actively involve community partners and link to local initiatives where possible, with support from Head teachers and business managers. Starting with what teachers, pupils and parents see as the barriers to health can create a whole school ethos for broad reaching and sustainable HPS programmes.All Saints Education Trust (ASET)National Institute for Health Research (NIHR
Evaluating the successful implementation of evidence into practice using the PARiHS framework : theoretical and practical challenges
Background
The PARiHS framework (Promoting Action on Research Implementation in Health Services) has proved to be a useful practical and conceptual heuristic for many researchers and practitioners in framing their research or knowledge translation endeavours. However, as a conceptual framework it still remains untested and therefore its contribution to the overall development and testing of theory in the field of implementation science is largely unquantified.
Discussion
This being the case, the paper provides an integrated summary of our conceptual and theoretical thinking so far and introduces a typology (derived from social policy analysis) used to distinguish between the terms conceptual framework, theory and model – important definitional and conceptual issues in trying to refine theoretical and methodological approaches to knowledge translation.
Secondly, the paper describes the next phase of our work, in particular concentrating on the conceptual thinking and mapping that has led to the generation of the hypothesis that the PARiHS framework is best utilised as a two-stage process: as a preliminary (diagnostic and evaluative) measure of the elements and sub-elements of evidence (E) and context (C), and then using the aggregated data from these measures to determine the most appropriate facilitation method. The exact nature of the intervention is thus determined by the specific actors in the specific context at a specific time and place.
In the process of refining this next phase of our work, we have had to consider the wider issues around the use of theories to inform and shape our research activity; the ongoing challenges of developing robust and sensitive measures; facilitation as an intervention for getting research into practice; and finally to note how the current debates around evidence into practice are adopting wider notions that fit innovations more generally.
Summary
The paper concludes by suggesting that the future direction of the work on the PARiHS framework is to develop a two-stage diagnostic and evaluative approach, where the intervention is shaped and moulded by the information gathered about the specific situation and from participating stakeholders. In order to expedite the generation of new evidence and testing of emerging theories, we suggest the formation of an international research implementation science collaborative that can systematically collect and analyse experiences of using and testing the PARiHS framework and similar conceptual and theoretical approaches.
We also recommend further refinement of the definitions around conceptual framework, theory, and model, suggesting a wider discussion that embraces multiple epistemological and ontological perspectives
Nesprin-2 interacts with meckelin and mediates ciliogenesis via remodelling of the actin cytoskeleton.
addresses: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.notes: PMCID: PMC2909318types: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2009 Company of Biologists.Meckel-Gruber syndrome (MKS) is a severe autosomal recessively inherited disorder caused by mutations in genes that encode components of the primary cilium and basal body. Here we show that two MKS proteins, MKS1 and meckelin, that are required for centrosome migration and ciliogenesis interact with actin-binding isoforms of nesprin-2 (nuclear envelope spectrin repeat protein 2, also known as Syne-2 and NUANCE). Nesprins are important scaffold proteins for maintenance of the actin cytoskeleton, nuclear positioning and nuclear-envelope architecture. However, in ciliated-cell models, meckelin and nesprin-2 isoforms colocalized at filopodia prior to the establishment of cell polarity and ciliogenesis. Loss of nesprin-2 and nesprin-1 shows that both mediate centrosome migration and are then essential for ciliogenesis, but do not otherwise affect apical-basal polarity. Loss of meckelin (by siRNA and in a patient cell-line) caused a dramatic remodelling of the actin cytoskeleton, aberrant localization of nesprin-2 isoforms to actin stress-fibres and activation of RhoA signalling. These findings further highlight the important roles of the nesprins during cellular and developmental processes, particularly in general organelle positioning, and suggest that a mechanistic link between centrosome positioning, cell polarity and the actin cytoskeleton is required for centrosomal migration and is essential for early ciliogenesis
Alcohol affects neuronal substrates of response inhibition but not of perceptual processing of stimuli signalling a stop response
Alcohol impairs inhibitory control, including the ability to terminate an initiated action. While there is increasing knowledge about neural mechanisms involved in response inhibition, the level at which alcohol impairs such mechanisms remains poorly understood. Thirty-nine healthy social drinkers received either 0.4g/kg or 0.8g/kg of alcohol, or placebo, and performed two variants of a Visual Stop-signal task during acquisition of functional magnetic resonance imaging (fMRI) data. The two task variants differed only in their instructions: in the classic variant (VSST), participants inhibited their response to a “Go-stimulus” when it was followed by a “Stop-stimulus”. In the control variant (VSST_C), participants responded to the “Go-stimulus” even if it was followed by a “Stop-stimulus”. Comparison of successful Stop-trials (Sstop)>Go, and unsuccessful Stop-trials (Ustop)>Sstop between the three beverage groups enabled the identification of alcohol effects on functional neural circuits supporting inhibitory behaviour and error processing. Alcohol impaired inhibitory control as measured by the Stop-signal reaction time, but did not affect other aspects of VSST performance, nor performance on the VSST_C. The low alcohol dose evoked changes in neural activity within prefrontal, temporal, occipital and motor cortices. The high alcohol dose evoked changes in activity in areas affected by the low dose but importantly induced changes in activity within subcortical centres including the globus pallidus and thalamus. Alcohol did not affect neural correlates of perceptual processing of infrequent cues, as revealed by conjunction analyses of VSST and VSST_C tasks. Alcohol ingestion compromises the inhibitory control of action by modulating cortical regions supporting attentional, sensorimotor and action-planning processes. At higher doses the impact of alcohol also extends to affect subcortical nodes of fronto-basal ganglia- thalamo-cortical motor circuits. In contrast, alcohol appears to have little impact on the early visual processing of infrequent perceptual cues. These observations clarify clinically-important effects of alcohol on behaviour
Coral adaptive capacity insufficient to halt global transition of coral reefs into net erosion under climate change
This is the final version. Available from Wiley via the DOI in this record. DATA AVAILABILITY STATEMENT:
All data submitted to dryad https://doi.org/10.5061/dryad.5hqbz
kh9vProjecting the effects of climate change on net reef calcium carbonate production is critical to understanding the future impacts on ecosystem function, but prior estimates have not included corals' natural adaptive capacity to such change. Here we estimate how the ability of symbionts to evolve tolerance to heat stress, or for coral hosts to shuffle to favourable symbionts, and their combination, may influence responses to the combined impacts of ocean warming and acidification under three representative concentration pathway (RCP) emissions scenarios (RCP2.6, RCP4.5 and RCP8.5). We show that symbiont evolution and shuffling, both individually and when combined, favours persistent positive net reef calcium carbonate production. However, our projections of future net calcium carbonate production (NCCP) under climate change vary both spatially and by RCP. For example, 19%–35% of modelled coral reefs are still projected to have net positive NCCP by 2050 if symbionts can evolve increased thermal tolerance, depending on the RCP. Without symbiont adaptive capacity, the number of coral reefs with positive NCCP drops to 9%–13% by 2050. Accounting for both symbiont evolution and shuffling, we project median positive NCPP of coral reefs will still occur under low greenhouse emissions (RCP2.6) in the Indian Ocean, and even under moderate emissions (RCP4.5) in the Pacific Ocean. However, adaptive capacity will be insufficient to halt the transition of coral reefs globally into erosion by 2050 under severe emissions scenarios (RCP8.5).Royal Society Te ApārangiVictoria University of Wellingto
A habituation account of change detection in same/different judgments
We investigated the basis of change detection in a short-term priming task. In two experiments, participants were asked to indicate whether or not a target word was the same as a previously presented cue. Data from an experiment measuring magnetoencephalography failed to find different patterns for “same” and “different” responses, consistent with the claim that both arise from a common neural source, with response magnitude defining the difference between immediate novelty versus familiarity. In a behavioral experiment, we tested and confirmed the predictions of a habituation account of these judgments by comparing conditions in which the target, the cue, or neither was primed by its presentation in the previous trial. As predicted, cue-primed trials had faster response times, and target-primed trials had slower response times relative to the neither-primed baseline. These results were obtained irrespective of response repetition and stimulus–response contingencies. The behavioral and brain activity data support the view that detection of change drives performance in these tasks and that the underlying mechanism is neuronal habituation
Masked-Volume-Wise PCA and "reference Logan" illustrate similar regional differences in kinetic behavior in human brain PET study using [11C]-PIB
<p>Abstract</p> <p>Background</p> <p>Kinetic modeling using reference Logan is commonly used to analyze data obtained from dynamic Positron Emission Tomography (PET) studies on patients with Alzheimer's disease (AD) and healthy volunteers (HVs) using amyloid imaging agent <it>N</it>-methyl [<sup>11</sup>C]2-(4'-methylaminophenyl)-6-hydroxy-benzothiazole, [<sup>11</sup>C]-PIB. The aim of the present study was to explore whether results obtained using the newly introduced method, Masked Volume Wise Principal Component Analysis, MVW-PCA, were similar to the results obtained using reference Logan.</p> <p>Methods</p> <p>MVW-PCA and reference Logan were performed on dynamic PET images obtained from four Alzheimer's disease (AD) patients on two occasions (baseline and follow-up) and on four healthy volunteers (HVs). Regions of interest (ROIs) of similar sizes were positioned in different parts of the brain in both AD patients and HVs where the difference between AD patients and HVs is largest. Signal-to-noise ratio (SNR) and discrimination power (DP) were calculated for images generated by the different methods and the results were compared both qualitatively and quantitatively.</p> <p>Results</p> <p>MVW-PCA generated images that illustrated similar regional binding patterns compared to reference Logan images and with slightly higher quality, enhanced contrast, improved SNR and DP, without being based on modeling assumptions. MVW-PCA also generated additional MVW-PC images by using the whole dataset, which illustrated regions with different and uncorrelated kinetic behaviors of the administered tracer. This additional information might improve the understanding of kinetic behavior of the administered tracer.</p> <p>Conclusion</p> <p>MVW-PCA is a potential multivariate method that without modeling assumptions generates high quality images, which illustrated similar regional changes compared to modeling methods such as reference Logan. In addition, MVW-PCA could be used as a new technique, applicable not only on dynamic human brain studies but also on dynamic cardiac studies when using PET.</p
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