183 research outputs found

    Experimental and theoretical investigations of a supercavitating hydrofoil

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    An experimental investigation of the two-dimensional hydrodynamic characteristics of a thin, supercavitating hydrofoil is described. The effects of twist and vibration of the thin hydrofoil model are considered, and experimental techniques for investigating spanwise twist and leading edge vibration and data correction methods are described. The theory of Wu for the forces on fully cavitating hydrofoils was used to calculate the forces on this profile. The calculated lift is in good agreement with the experimental results; however, the measured drag differs appreciably from the theoretical values

    Depression among women of reproductive age in rural Bangladesh is linked to food security, diets and nutrition

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    Objective: To quantify the relationship between screening positive for depression and several indicators of the food and nutrition environment in Bangladesh. Design: We used cross-sectional data from the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) trial in Bangladesh to examine the association of depression in non-peripartum (NPW) and peripartum women (PW) with food and nutrition security using multivariable logistic regression and dominance analysis. Setting: Rural north-eastern Bangladesh. Participants: Women of reproductive age. Results: Of 2599 women, 40 % were pregnant or up to 1 year postpartum, while 60 % were not peripartum. Overall, 20 % of women screened positive for major depression. In the dominance analysis, indicators of food and nutrition security were among the strongest explanatory factors of depression. Food insecurity (HFIAS) and poor household food consumption (FCS) were associated with more than double the odds of depression (HFIAS: NPW OR = 2·74 and PW OR = 3·22; FCS: NPW OR = 2·38 and PW OR = 2·44). Low dietary diversity (<5 food groups) was associated with approximately double the odds of depression in NPW (OR = 1·80) and PW (OR = 1·99). Consumption of dairy, eggs, fish, vitamin A-rich and vitamin C-rich foods was associated with reduced odds of depression. Anaemia was not associated with depression. Low BMI (<18·5 kg/m2) was also associated with depression (NPW: OR = 1·40). Conclusions: Depression among women in Bangladesh was associated with many aspects of food and nutrition security, also after controlling for socio-economic factors. Further investigation into the direction of causality and interventions to improve diets and reduce depression among women in low- and middle-income countries are urgently needed

    Food and Agricultural Approaches to Reducing Malnutrition (FAARM): protocol for a cluster-randomised controlled trial to evaluate the impact of a Homestead Food Production programme on undernutrition in rural Bangladesh

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    IntroductionChronic undernutrition affects over 150 million children worldwide and has serious consequences. The causes are complex and include insufficient dietary diversity and poor hygiene practices. Systematic reviews of nutrition-sensitive agricultural interventions concluded that while these hold promise, there is insufficient evidence for their impact on child growth. The Food and Agricultural Approaches to Reducing Malnutrition (FAARM) project is a 1:1 cluster-randomised trial aiming to evaluate the impact of a Homestead Food Production (HFP) programme implemented by Helen Keller International on women’s and children’s undernutrition.Methods and analysisThe HFP intervention comprises training of women’s groups and asset distribution to support year-round home gardening, poultry rearing and improved nutrition and hygiene practices. Formal trainings are supplemented by behaviour change communication during household visits, and facilitated links between producer groups and market actors. The FAARM trial will examine if and how this complex intervention reduces undernutrition. In 2015, FAARM enrolled married women and their children (0–3 years) in 96 rural settlements of Habiganj district in Sylhet division, Bangladesh. Covariate-constrained randomisation was used to assign 48 settlements to receive a 3-year HFP intervention, with the other 48 acting as controls, targeting over 2700 women. To study impact pathways, a surveillance system collects data on all participants every 2 months. In late 2019, children 0–3 years of age (born during the intervention period) will be surveyed, thus capturing impact during the critical first 1000 days of life. Children’s length/height-for-age z-scores will be compared between intervention and control arms using mixed-effects linear regression. Secondary outcomes include women’s and children’s micronutrient status, dietary intake, dietary diversity and other indicators of child growth, development and morbidity.Ethics and disseminationEthical approval was received in Bangladesh and Germany. Results will be disseminated through peer-reviewed publications and presentations in Bangladesh and internationally.Trial registration numberNCT02505711; Pre-results.</jats:sec

    Carbon Nanotube-Enhanced Carbon-Phenenolic Ablator Material

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    This viewgraph presentation reviews the use of PICA (phenolic impregnated carbon ablator) as the selected material for heat shielding for future earth return vehicles. It briefly reviews the manufacturing of PICA and the advantages for the use of heat shielding, and then explains the reason for using Carbon Nanotubes to improve strength of phenolic resin that binds carbon fibers together. It reviews the work being done to create a carbon nanotube enhanced PICA. Also shown are various micrographic images of the various PICA materials

    Time and Encoding Effects in the Concealed Knowledge Test

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    Although the traditional “lie detector” test is used frequently in forensic contexts, it has (like most test of deception) some limitations. The concealed knowledge test (CKT) focuses on participants’ recognition of privileged knowledge rather than lying per-se and has been studied extensively using a variety of measures. A “guilty” suspect’s interaction with and memory of crimescene items may vary. Furthermore, memory for crimescene items may diminish over time. The interaction of encoding quality and test delay on CKT efficiency has been previously implied, but not yet demonstrated. We used a response-time based CKT to detect concealed knowledge from shallow and deep study procedures after 10-min, 24-h, and 1-week delays. Results show that more elaborately encoded information afforded higher detection accuracy than poorly encoded items. Although classification accuracy following deep study was unaffected by delay, detection of poorly elaborated information was initially high, but compromised after 1 week. Thus, choosing optimal test items requires considering both test delay and initial encoding level

    Galectin-9 Controls CD40 Signaling through a Tim-3 Independent Mechanism and Redirects the Cytokine Profile of Pathogenic T Cells in Autoimmunity

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    While it has long been understood that CD40 plays a critical role in the etiology of autoimmunity, glycobiology is emerging as an important contributor. CD40 signaling is also gaining further interest in transplantation and cancer therapies. Work on CD40 signaling has focused on signaling outcomes and blocking of its ligand, CD154, while little is known about the actual receptor itself and its control. We demonstrated that CD40 is in fact several receptors occurring as constellations of differentially glycosylated forms of the protein that can sometimes form hybrid receptors with other proteins. An enticing area of autoimmunity is differential glycosylation of immune molecules leading to altered signaling. Galectins interact with carbohydrates on proteins to effect such signaling alterations. Studying autoimmune prone NOD and non-autoimmune BALB/c mice, here we reveal that in-vivo CD40 signals alter the glycosylation status of non-autoimmune derived CD4 T cells to resemble that of autoimmune derived CD4 T cells. Galectin-9 interacts with CD40 and, at higher concentrations, prevents CD40 induced proliferative responses of CD4loCD40+ effector T cells and induces cell death through a Tim-3 independent mechanism. Interestingly, galectin-9, at lower concentrations, alters the surface expression of CD3, CD4, and TCR, regulating access to those molecules and thereby redirects the inflammatory cytokine phenotype and CD3 induced proliferation of autoimmune CD4loCD40+ T cells. Understanding the dynamics of the CD40 receptor(s) and the impact of glycosylation status in immunity will gain insight into how to maintain useful CD40 signals while shutting down detrimental ones

    High Distribution of CD40 and TRAF2 in Th40 T Cell Rafts Leads to Preferential Survival of this Auto-Aggressive Population in Autoimmunity

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    CD40-CD154 interactions have proven critical in autoimmunity, with the identification of CD4(lo)CD40(+) T cells (Th40 cells) as harboring an autoaggressive T cell population shedding new insights into those disease processes. Th40 cells are present at contained levels in non-autoimmune individuals but are significantly expanded in autoimmunity. Th40 cells are necessary and sufficient in transferring type 1 diabetes in mouse models. However, little is known about CD40 signaling in T cells and whether there are differences in that signaling and subsequent outcome depending on disease conditions. When CD40 is engaged, CD40 and TNF-receptor associated factors, TRAFs, become associated with lipid raft microdomains. Dysregulation of T cell homeostasis is emerging as a major contributor to autoimmune disease and thwarted apoptosis is key in breaking homeostasis.Cells were sorted into CD4(hi) and CD4(lo) (Th40 cells) then treated and assayed either as whole or fractionated cell lysates. Protein expression was assayed by western blot and Nf-kappaB DNA-binding activity by electrophoretic mobility shifts. We demonstrate here that autoimmune NOD Th40 cells have drastically exaggerated expression of CD40 on a per-cell-basis compared to non-autoimmune BALB/c. Immediately ex-vivo, untreated Th40 cells from NOD mice have high levels of CD40 and TRAF2 associated with the raft microdomain while Th40 cells from NOR and BALB/c mice do not. CD40 engagement of Th40 cells induces Nf-kappaB DNA-binding activity and anti-apoptotic Bcl-X(L) expression in all three mouse strains. However, only in NOD Th40 cells is anti-apoptotic cFLIP(p43) induced which leads to preferential survival and proliferation. Importantly, CD40 engagement rescues NOD Th40 cells from Fas-induced death.CD40 may act as a switch between life and death promoting signals and NOD Th40 cells are poised for survival via this switch. This may explain how they expand in autoimmunity to thwart T cell homeostasis
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