257 research outputs found

    Filler wire for aluminum alloys and method of welding

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    A weld filler wire chemistry has been developed for fusion welding 2195 aluminum-lithium. The weld filler wire chemistry is an aluminum-copper based alloy containing high additions of titanium and zirconium. The additions of titanium and zirconium reduce the crack susceptibility of aluminum alloy welds while producing good weld mechanical properties. The addition of silver further improves the weld properties of the weld filler wire. The reduced weld crack susceptibility enhances the repair weldability, including when planishing is required

    Full-Scale GRCop-84 Combustion Chamber Liner Preform Fabricated Successfully

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    GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) has been under development at the NASA Glenn Research Center for several years. The alloy possesses a unique combination of good thermal conductivity, high elevated temperature strength, long creep life, and long low-cycle- fatigue. The alloy is also more oxidation resistant than pure copper and most competitive alloys. The combination of properties has attracted attention from major rocket engine manufacturers who are interested in the alloy for the combustion chamber liner in their next generation of regeneratively cooled engines. Before GRCop-84 can be used in a main combustion chamber application, it must be demonstrated that the alloy can be made successfully to the large sizes and proper shape needed and that it retain useful properties. Recent efforts have successfully demonstrated the ability to fabricate a liner preform via metal spinning that retains the alloy s strength even in the welded sections

    A comprehensive map of insulator elements for the Drosophila genome.

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    Insulators are DNA sequences that control the interactions among genomic regulatory elements and act as chromatin boundaries. A thorough understanding of their location and function is necessary to address the complexities of metazoan gene regulation. We studied by ChIP-chip the genome-wide binding sites of 6 insulator-associated proteins-dCTCF, CP190, BEAF-32, Su(Hw), Mod(mdg4), and GAF-to obtain the first comprehensive map of insulator elements in Drosophila embryos. We identify over 14,000 putative insulators, including all classically defined insulators. We find two major classes of insulators defined by dCTCF/CP190/BEAF-32 and Su(Hw), respectively. Distributional analyses of insulators revealed that particular sub-classes of insulator elements are excluded between cis-regulatory elements and their target promoters; divide differentially expressed, alternative, and divergent promoters; act as chromatin boundaries; are associated with chromosomal breakpoints among species; and are embedded within active chromatin domains. Together, these results provide a map demarcating the boundaries of gene regulatory units and a framework for understanding insulator function during the development and evolution of Drosophila

    Interventions to prevent obesity in children aged 5 to 11 years old

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    Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. The overall aim of the review is to determine the effectiveness of interventions to prevent obesity in 5 to 11-year-old children. The four objectives are:. to evaluate the effects of interventions that aim to modify dietary intake on changes in zBMI score, BMI and serious adverse events among children; to evaluate the effects of interventions that aim to modify physical activity, sedentary behaviour, sleep, play and/or structured exercise on changes in zBMI score, BMI and serious adverse events among children; to evaluate the combined effects of interventions that aim to modify both dietary intake and physical activity/movement behaviours on changes in zBMI score, BMI and serious adverse events among children; to compare the effects of interventions that aim to modify dietary interventions with those that aim to modify physical activity/movement behaviours on changes in zBMI score, BMI and serious adverse events among children. The secondary objectives are designed to explore if, how, and why the effectiveness of interventions on zBMI/BMI varies depending on the following PROGRESS factors. Place of residence Race/ethnicity/culture/language Occupation Gender/sex Religion Education Socioeconomic status Social capital. The PROGRESS acronym is intended to ensure that there is explicit consideration of health inequity, the unfair difference in disease burden, when conducting research and adapting research evidence to inform the design of new interventions (O'Neill 2014). The PROGRESS acronym describes factors that contribute to health inequity. Recent work on race and religion in the UK suggests that consideration of these factors is critical to the design of new interventions (Rai 2019). We will also collect, from RCTs, information about the costs of interventions so that policymakers can use the review as a source of information from which they may prepare cost-effectiveness analyses

    Interventions to prevent obesity in children aged 12 to 18 years old 

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    Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. The overall aim of the review is to determine the effectiveness of interventions to prevent obesity in 12 to 18-year-old children and adolescents. The four objectives are:. to evaluate the effects of interventions that aim to modify dietary intake on changes in zBMI score, BMI and serious adverse events among children and adolescents; to evaluate the effects of interventions that aim to modify physical activity, sedentary behaviour, sleep, play and/or structured exercise on changes in zBMI score, BMI and serious adverse events among children and adolescents; to evaluate the combined effects of interventions that aim to modify both dietary intake and physical activity/movement behaviours on changes in zBMI score, BMI and serious adverse events among children and adolescents; to compare the effects of interventions that aim to modify dietary interventions with those that aim to modify physical activity/movement behaviours on changes in zBMI score, BMI and serious adverse events among children. The secondary objectives are designed to explore if, how, and why the effectiveness of interventions on zBMI/BMI varies depending on the following PROGRESS factors. Place of residence Race/ethnicity/culture/language Occupation Gender/sex Religion Education Socioeconomic status Social capital. The PROGRESS acronym is intended to ensure that there is explicit consideration of health inequity, the unfair difference in disease burden, when conducting research and adapting research evidence to inform the design of new interventions (O'Neill 2014). The PROGRESS acronym describes factors that contribute to health inequity. Recent work on race and religion in the UK suggested that consideration of these factors is critical to the design of new interventions (Rai 2019). We will also collect, from RCTs, information about the costs of interventions so that policymakers can use the review as a source of information from which they may prepare cost-effectiveness analyses

    Genetic Architecture of Soybean Yield and Agronomic Traits

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    Soybean is the world’s leading source of vegetable protein and demand for its seed continues to grow. Breeders have successfully increased soybean yield, but the genetic architecture of yield and key agronomic traits is poorly understood. We developed a 40-mating soybean nested association mapping (NAM) population of 5,600 inbred lines that were characterized by single nucleotide polymorphism (SNP) markers and six agronomic traits in field trials in 22 environments. Analysis of the yield, agronomic, and SNP data revealed 23 significant marker-trait associations for yield, 19 for maturity, 15 for plant height, 17 for plant lodging, and 29 for seed mass. A higher frequency of estimated positive yield alleles was evident from elite founder parents than from exotic founders, although unique desirable alleles from the exotic group were identified, demonstrating the value of expanding the genetic base of US soybean breeding

    KAF156 is an antimalarial clinical candidate with potential for use in prophylaxis, treatment, and prevention of disease transmission

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    Renewed global efforts toward malaria eradication have highlighted the need for novel antimalarial agents with activity against multiple stages of the parasite life cycle. We have previously reported the discovery of a novel class of antimalarial compounds in the imidazolopiperazine series that have activity in the prevention and treatment of blood stage infection in a mouse model of malaria. Consistent with the previously reported activity profile of this series, the clinical candidate KAF156 shows blood schizonticidal activity with 50% inhibitory concentrations of 6 to 17.4 nM against P. falciparum drug-sensitive and drug-resistant strains, as well as potent therapeutic activity in a mouse models of malaria with 50, 90, and 99% effective doses of 0.6, 0.9, and 1.4 mg/kg, respectively. When administered prophylactically in a sporozoite challenge mouse model, KAF156 is completely protective as a single oral dose of 10 mg/kg. Finally, KAF156 displays potent Plasmodium transmission blocking activities both in vitro and in vivo. Collectively, our data suggest that KAF156, currently under evaluation in clinical trials, has the potential to treat, prevent, and block the transmission of malaria

    The Regulation of Sulfur Metabolism in Mycobacterium tuberculosis

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    Mycobacterium tuberculosis (Mtb) has evolved into a highly successful human pathogen. It deftly subverts the bactericidal mechanisms of alveolar macrophages, ultimately inducing granuloma formation and establishing long-term residence in the host. These hallmarks of Mtb infection are facilitated by the metabolic adaptation of the pathogen to its surrounding environment and the biosynthesis of molecules that mediate its interactions with host immune cells. The sulfate assimilation pathway of Mtb produces a number of sulfur-containing metabolites with important contributions to pathogenesis and survival. This pathway is regulated by diverse environmental cues and regulatory proteins that mediate sulfur transactions in the cell. Here, we discuss the transcriptional and biochemical mechanisms of sulfur metabolism regulation in Mtb and potential small molecule regulators of the sulfate assimilation pathway that are collectively poised to aid this intracellular pathogen in its expert manipulation of the host. From this global analysis, we have identified a subset of sulfur-metabolizing enzymes that are sensitive to multiple regulatory cues and may be strong candidates for therapeutic intervention
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