11 research outputs found

    Electric Turbo Pump

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    NASA is working in junction with another company on the Electric Turbo Pump. Analysis of the impeller, including the blades, volute housing, and associated components, will take place in ANSYS. Contours of the deformed and stress were recorded to assess the parts. Campbell diagrams will be considered as mentioned to find the operating regions of the impeller and volute housing, more specifically what speed is ideal to ensure that the impeller does not begin to vibrate at a frequency that will break it. More than one material will be examined as per request by the designer to determine which material is more cost efficient, easy to machine, and can withstand the stress values that will be placed on it

    Sediment Delivery to Sustain the Ganges-Brahmaputra Delta Under Climate Change and Anthropogenic Impacts

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    The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers’ ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to previously modeled results and suggest that increased sediment delivery may be capable of offsetting accelerated sea-level rise. This prospect for a naturally sustained Ganges-Brahmaputra delta presents possibilities beyond the dystopian future often posed for this system, but the implementation of currently proposed dams and diversions would preclude such opportunities

    School climate and implementation of the Pathways study.

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    BACKGROUND: Pathways was a multisite school-based study to prevent obesity in American Indian school children by encouraging healthy eating and physical activity. METHODS: Over the 3-year study, a total of 290 in-depth interviews were conducted with school administrators, food service managers, classroom teachers, and physical education instructors in all 21 intervention schools to examine support and barriers for Pathways. Analysis included qualitative assessment of key themes using NUD*IST and quantitative modeling of the impact of a school climate score on implementation of intervention components. RESULTS: Overall, teachers, food service managers, and physical education instructors were supportive of the Pathways interventions. School administration and lack of family participation were perceived barriers at some schools. Attitudes toward the program ranged from neutral to positive during the first year, with about two-thirds giving positive ratings, with greater variation in successive years. Overall, the mean score was 3.5 on a 5-point scale (1=very negative, 5=very positive). School climate score was positively associated with classroom curriculum and student exposure indices, but not with family attendance, food service, or physical activity implementation indices. The latter two indices were associated with site. CONCLUSIONS: An assessment of school climate through interviews is useful in understanding successes and failures in a school-based health intervention and can predict implementation success for some programs

    Systematic review of the design, implementation and effectiveness of mass media and nutrition education interventions for infant and young child feeding

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    Objective: To systematically review the design, implementation and effectiveness of mass media and nutrition education interventions for improving infant and young child feeding (IYCF) practices and related psychosocial factors. Design: A search of PubMed, Embase and PsycINFO databases, a Google search, and a consultation with experts in the field of IYCF performed in July 2016. Setting: Low- and middle-income countries, as defined by the World Bank Group. Subjects: Eligible studies: included a mass media component (with or without nutrition education); conducted a pre–post evaluation (with or without a control group); assessed IYCF knowledge, attitudes, beliefs and/or practices; and were published in English between 2000 and present. Results: Eighteen unique studies were identified that examined the effect of mass media (types included: television; print; voice and/or SMS (text) messages; radio; megaphones/loudspeakers; videos; social media; songs/dramas) and nutrition education interventions on IYCF practices within thirteen countries. Of these, fifteen studies reported improvements in breast- and/or complementary feeding practices, using indicators recommended by the WHO, and six studies reported improvements in related psychosocial factors. However, little detail was provided on the use of formative research, a formal behaviour change theory and behaviour change techniques. Few studies reported both dose delivered and participants’ exposure to the intervention. Conclusions: Despite evidence of effectiveness, few common elements in the design of interventions were identified. Future research should consistently report these details to open the ‘black box’ of IYCF interventions, identify effective design components and ensure replicability

    Practical solutions for including Sex As a Biological Variable (SABV) in preclinical neuropsychopharmacological research.

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    Recently, many funding agencies have released guidelines on the importance of considering sex as a biological variable (SABV) as an experimental factor, aiming to address sex differences and avoid possible sex biases to enhance the reproducibility and translational relevance of preclinical research. In neuroscience and pharmacology, the female sex is often omitted from experimental designs, with researchers generalizing male-driven outcomes to both sexes, risking a biased or limited understanding of disease mechanisms and thus potentially ineffective therapeutics. Herein, we describe key methodological aspects that should be considered when sex is factored into in vitro and in vivo experiments and provide practical knowledge for researchers to incorporate SABV into preclinical research. Both age and sex significantly influence biological and behavioral processes due to critical changes at different timepoints of development for males and females and due to hormonal fluctuations across the rodent lifespan. We show that including both sexes does not require larger sample sizes, and even if sex is included as an independent variable in the study design, a moderate increase in sample size is sufficient. Moreover, the importance of tracking hormone levels in both sexes and the differentiation between sex differences and sex-related strategy in behaviors are explained. Finally, the lack of robust data on how biological sex influences the pharmacokinetic (PK), pharmacodynamic (PD), or toxicological effects of various preclinically administered drugs to animals due to the exclusion of female animals is discussed, and methodological strategies to enhance the rigor and translational relevance of preclinical research are proposed

    Genetic and Pharmacological Modulation of the Steroid Sulfatase Axis Improves Response Control; Comparison with Drugs Used in ADHD

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    Maladaptive response control is a feature of many neuropsychiatric conditions, including Attention Deficit Hyperactivity Disorder (ADHD). As ADHD is more commonly diagnosed in males than females, a pathogenic role for sex-linked genes has been suggested. Deletion or point mutation of the X-linked STS gene, encoding the enzyme steroid sulfatase influences risk for ADHD. We examined whether deletion of the Sts gene in the 39,XY*O mouse model, or pharmacological manipulation of the steroid sulfatase axis, via administration of the enzyme substrate dehydroepiandrosterone sulfate or the enzyme inhibitor COUMATE, influenced behavior in a novel murine analogue of the stop-signal reaction time task used to detect inhibitory deficits in individuals with ADHD. Unexpectedly, both the genetic and pharmacological treatments resulted in enhanced response control, manifest as highly specific effects in the ability to cancel a pre-potent action. For all three manipulations, the effect size was comparable to that seen with the commonly used ADHD therapeutics methylphenidate and atomoxetine. Hence, converging genetic and pharmacological evidence indicate that the steroid sulfatase axis is involved in inhibitory processes and can be manipulated to give rise to improvements in response control. Whilst the precise neurobiological mechanism(s) underlying the effects remain to be established, there is the potential for exploiting this pathway in the treatment of disorders where failures in behavioral inhibition are prominent
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