3,186 research outputs found

    An experimental study of the turbulent boundary layer on a transport wing in subsonic and transonic flow

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    The upper surface boundary layer on a transport wing model was extensively surveyed with miniature yaw probes at a subsonic and a transonic cruise condition. Additional data were obtained at a second transonic test condition, for which a separated region was present at mid-semispan, aft of mid-chord. Significant variation in flow direction with distance from the surface was observed near the trailing edge except at the wing root and tip. The data collected at the transonic cruise condition show boundary layer growth associated with shock wave/boundary layer interaction, followed by recovery of the boundary layer downstream of the shock. Measurements of fluctuating surface pressure and wingtip acceleration were also obtained. The influence of flow field unsteadiness on the boundary layer data is discussed. Comparisons among the data and predictions from a variety of computational methods are presented. The computed predictions are in reasonable agreement with the experimental data in the outboard regions where 3-D effects are moderate and adverse pressure gradients are mild. In the more highly loaded mid-span region near the trailing edge, displacement thickness growth was significantly underpredicted, except when unrealistically severe adverse pressure gradients associated with inviscid calculations were used to perform boundary layer calculations

    Kenyan Youth Perspectives on Forests : report from a youth-scientist dialogue on sustainable forestry

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    This report presents proceedings of “AfricanYouth4Forests” project workshop held in Voi, Taita Taveta county, Kenya from 7 to 9 November 2022. The workshop was jointly organised by African Forest Forum (AFF), Swedish University of Agricultural Sciences (SLU), and Kenya Forestry Research Institute (KEFRI). It brought together 19 youths from Taita Taveta and Nairobi counties between 18-25 years of age to engage with researchers and policymakers in conversations about young people's views, visions, goals, and ideas in shaping the future governance of Kenya’s and the continent's forests.  The participants identified niches for youths' engagement in forests to improve forest cover, curb climate change effects and improve livelihoods. The youth participants envisioned 'a world where young people are more involved in sustainable development by participating in the green economy.' To achieve the youths’ vision, several actions were recommended; training the youth on sustainable forest management and green entrepreneurship, developing markets for green products, establishing innovative knowledge-sharing platforms, and actively involving the youths in national and international policy processes on forests and climate change. The outcome reflected a wide range of views and ideas among the youth, and that they have the capacity and readiness to tackle the forest-related challenges towards 2030 and beyond. It is recommended that the dialogue between African forestry researchers and the youth should continue

    Health, community and development : towards a social psychology of participation

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    Population ageing is one of the major contemporary issues facing societies across the world. Originally framed as a major social and economic challenge, demographic ageing is now beginning to be seen as offering huge potential to individuals as well as to their communities. It is this positive potential that we explore in this issue by utilising two key disciplinary approaches—social gerontology and social/community psychology. In this introduction, we argue that focus on only one or the other of these perspectives is limiting. Instead, a more critical approach is needed that incorporates the strengths of both disciplines in order to build a more complete and stronger understanding of ageing and community. Thus, a focus on social gerontology highlights ageing issues and explores the diversity of older people and their interactions with community. By incorporating a social/community psychology approach, there is potential to complement this body of work through a deeper level of analysis around community, as well as individual and relational dimensions. The result is a special issue that brings together these two perspectives to address some of the shortcomings of approaching ageing through solely one disciplinary lens

    Restriction of Measles Virus Gene Expression in Measles Inclusion Body Encephalitis

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    Measles virus (MV) infection in brain tissue of a patient with measles inclusion body encephalitis was characterized by immunologic and biochemical techniques. Of the five major structural proteins of MV, only nucleocapsid (N) protein and phosphoprotein (P protein) were consistently detected in diseased brain areas. In contrast, hemagglutinin protein was seen only occasionally, and no membrane and fusion proteins were found in any of the sections studied. Messenger RNAs (mRNAs) specific for these five viral proteins were detected in all brain extracts examined; however, the mRNAs for the envelope proteins were clearly underrepresented in comparison with lytically infected cells. Only the mRNAs for N and P proteins appeared active in in vitro translations. These findings indicate quantitative differences in the pattern of mRNA expression in brain tissue and a restricted expression of MV envelope proteins in infected cells as observed in subacute sclerosing panencephaliti

    Access to primary care for socio-economically disadvantaged older people in rural areas: A realist review

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    Objective: The aim of this review is to identify and understand the contexts that effect access to high quality primary care for socio-economically disadvantaged older people in rural areas. Design: A realist review Data sources: MEDLINE and EMBASE electronic databases and grey literature (from inception to Dec 2014). Eligibility criteria for selecting studies: Broad inclusion criteria were used to allow articles which were not specific, but might be relevant to the population of interest to be considered. Studies meeting the inclusion criteria were assessed for rigour and relevance and coded for concepts relating to context, mechanism or outcome. Analysis: An overarching patient pathway was generated and used as the basis to explore contexts, causal mechanisms and outcomes. Results: 162 articles were included. Most were from the USA or UK, cross sectional in design and presented subgroup data by age, rurality or deprivation. From these studies a patient pathway was generated which included seven steps (problem identified, decision to seek help, actively seek help, obtain appointment, get to appointment, primary care interaction and outcome). Important contexts were stoicism, education status, expectations of ageing, financial resources, understanding the health care system, access to suitable transport, capacity in primary care, the booking system and experience of health care. Prominent causal mechanisms were health literacy, perceived convenience, patient empowerment and responsiveness of the practice. Conclusions: Socio-economically disadvantaged older people in rural areas face personal, community and health care barriers that limit their access to primary care. Initiatives should be targeted at local contextual factors to help individuals recognise problems, feel welcome, navigate the health care system, book appointments easily, access appropriate transport and have sufficient time with professional staff to improve their experience of health care; all of which will require dedicated primary care resources

    Visuospatial Processing Deficits Linked to Posterior Brain Regions in Premanifest and Early Stage Huntington's Disease.

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    OBJECTIVES: Visuospatial processing deficits have been reported in Huntington's disease (HD). To date, no study has examined associations between visuospatial cognition and posterior brain findings in HD. METHODS: We compared 119 premanifest (55> and 64<10.8 years to expected disease onset) and 104 early symptomatic (59 stage-1 and 45 stage-2) gene carriers, with 110 controls on visual search and mental rotation performance at baseline and 12 months. In the disease groups, we also examined associations between task performance and disease severity, functional capacity and structural brain measures. RESULTS: Cross-sectionally, there were strong differences between all disease groups and controls on visual search, and between diagnosed groups and controls on mental rotation accuracy. Only the premanifest participants close to onset took longer than controls to respond correctly to mental rotation. Visual search negatively correlated with disease burden and motor symptoms in diagnosed individuals, and positively correlated with functional capacity. Mental rotation ("same") was negatively correlated with motor symptoms in stage-2 individuals, and positively correlated with functional capacity. Visual search and mental rotation were associated with parieto-occipital (pre-/cuneus, calcarine, lingual) and temporal (posterior fusiform) volume and cortical thickness. Longitudinally, visual search deteriorated over 12 months in stage-2 individuals, with no evidence of declines in mental rotation. CONCLUSIONS: Our findings provide evidence linking early visuospatial deficits to functioning and posterior cortical dysfunction in HD. The findings are important since large research efforts have focused on fronto-striatal mediated cognitive changes, with little attention given to aspects of cognition outside of these areas. (JINS, 2016, 22, 595-608)

    The origin of the Moon within a terrestrial synestia

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    The giant impact hypothesis remains the leading theory for lunar origin. However, current models struggle to explain the Moon's composition and isotopic similarity with Earth. Here we present a new lunar origin model. High-energy, high-angular momentum giant impacts can create a post-impact structure that exceeds the corotation limit (CoRoL), which defines the hottest thermal state and angular momentum possible for a corotating body. In a typical super-CoRoL body, traditional definitions of mantle, atmosphere and disk are not appropriate, and the body forms a new type of planetary structure, named a synestia. Using simulations of cooling synestias combined with dynamic, thermodynamic and geochemical calculations, we show that satellite formation from a synestia can produce the main features of our Moon. We find that cooling drives mixing of the structure, and condensation generates moonlets that orbit within the synestia, surrounded by tens of bars of bulk silicate Earth (BSE) vapor. The moonlets and growing moon are heated by the vapor until the first major element (Si) begins to vaporize and buffer the temperature. Moonlets equilibrate with BSE vapor at the temperature of silicate vaporization and the pressure of the structure, establishing the lunar isotopic composition and pattern of moderately volatile elements. Eventually, the cooling synestia recedes within the lunar orbit, terminating the main stage of lunar accretion. Our model shifts the paradigm for lunar origin from specifying a certain impact scenario to achieving a Moon-forming synestia. Giant impacts that produce potential Moon-forming synestias were common at the end of terrestrial planet formation.Comment: Accepted for publication in Journal of Geophysical Research: Planets. Main text: 44 pages, 24 figures. Supplement: 16 pages, 5 figures, 3 table

    A method for single pair mating in an obligate parasitic nematode

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    Parasitic nematode species have extremely high levels of genetic diversity, presenting a number of experimental challenges for genomic and genetic work. Consequently, there is a need to develop inbred laboratory strains with reduced levels of polymorphism. The most efficient approach to inbred line development is single pair mating, but this is challenging for obligate parasites where the adult sexual reproductive stages are inside the host, and thus difficult to experimentally manipulate. This paper describes a successful approach to single pair mating of a parasitic nematode, Haemonchus contortus. The method allows for polyandrous mating behaviour and involves the surgical transplantation of a single adult male worm with multiple immature adult females directly into the sheep abomasum. We used a panel of microsatellite markers to monitor and validate the single pair mating crosses and to ensure that the genotypes of progeny and subsequent filial generations were consistent with those expected from a mating between a single female parent of known genotype and a single male parent of unknown genotype. We have established two inbred lines that both show a significant overall reduction in genetic diversity based on microsatellite genotyping and genome-wide single nucleotide polymorphism. There was an approximately 50% reduction in heterozygous SNP sites across the genome in the MHco3.N1 line compared with the MoHco3(ISE) parental strain. The MHco3.N1 inbred line has subsequently been used to provide DNA template for whole genome sequencing of H. contortus. This work provides proof of concept and methodologies for forward genetic analysis of obligate parasitic nematodes
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