411 research outputs found

    Fluid management technology: Liquid slosh dynamics and control

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    Flight experiments were defined for the Cryogenic On-Orbit Liquid Depot Storage, Acquisition and Transfer Satellite (COLD-SAT) test bed satellite and the Shuttle middeck to help establish the influence of the gravitational environment on liquid slosh dynamics and control. Several analytical and experimental studies were also conducted to support the experiments and to help understand the anticipated results. Both FLOW-3D and NASA-VOF3D computer codes were utilized to simulate low Bond number, small amplitude sloshing, for which the motions are dominated by surface forces; it was found that neither code provided a satisfactory simulation. Thus, a new analysis of low Bond number sloshing was formulated, using an integral minimization technique that will allow the assumptions made about surface physics phenomena to be modified easily when better knowledge becomes available from flight experiments. Several examples were computed by the innovative use of a finite-element structural code. An existing spherical-pendulum analogy of nonlinear, rotary sloshing was also modified for easier use and extended to low-gravity conditions. Laboratory experiments were conducted to determine the requirements for liquid-vapor interface sensors as a method of resolving liquid surface motions in flight experiments. The feasibility of measuring the small slosh forces anticipated in flight experiments was also investigated

    Prevention of type 2 diabetes in urban American Indian/Alaskan Native communities: The Life in BALANCE pilot study

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    Objective: The Life in BALANCE (LIB) study is a pilot translational study modeling the Diabetes Prevention Program (DPP) intensive lifestyle coaching intervention among an underserved, high-risk population: American Indians/Alaska Natives (AI/ANs) living in a large urban setting (Las Vegas, Nevada). Research Design and Methods: A total of 22 overweight/obese AI/ANs (age, 39.6 ± 10.4 years; BMI, 34.1 ± 6.3 kg/m2) at increased risk for developing type 2 diabetes (HbA1c \u3e 5.4 (36 mmol/mol) \u3c 6.4 percent (46 mmol/mol) participated in the program between April and December, 2011. Study participants completed a 16 week intensive lifestyle coaching intervention. In addition to obtaining qualitative data regarding opportunities and challenges of applying the lifestyle intervention for AI/AN participants in an urban setting, clinical data, including BMI, waist circumference, blood pres- sure, fasting blood glucose, and blood lipids (HDL, LDL and Triglycerides), were collected. Results: Only 12 of the 22 participants remained in the LIB program at the final post-program follow-up. Participants demonstrated significant decreased waist circumference and elevated HDL cholesterol. Triglycerides manifested the highest percentage change without statistical significance. No significant change was ob- served in blood pressure or fasting blood glucose. Conclusions: LIB participants’ improvements in BMI, waist circumference, HDL cholesterol and triglycerides suggests type 2 diabetes prevention programs aimed at urban AI/ANs show significant potential for reducing the risk of developing type 2 diabetes among this underserved and high risk community. Qualitative data suggest the main challenge for type 2 diabetes prevention specific to this population is a need for improved community outreach strategies

    Growth and Survivorship of Scleractinian Coral Transplants and the Effectiveness of Plugging Core Holes in Transplant Donor Colonies

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    Replicate scleractinian coral transplants were obtained from the species Meandrina meandrites and Montastrea cavernosa on a natural reef, off Dania Beach, Florida, using a hydraulic drill fitted with a 4 in. (~10 cm) core barrel. The transplants were fixed to Reef Ball™ substrates using an adhesive marine epoxy. Drill holes in the donor corals (core holes) were filled with concrete plugs. Control corals, of comparable size to both donor colonies and transplant corals, were monitored for comparison. Transplant corals, donor corals, and controls on the natural reef were monitored for growth and survivorship. Core holes were monitored for tissue regrowth over the surface of concrete plugs. Growth during the transplantation project was defined as an increase in surface area of tissue and skeleton. Growth was monitored on a quarterly basis using photographic techniques. Meandrina meandrites transplants experienced greater mortality and significantly less growth than M. cavernosa transplants. No significant difference in the change in percent tissue coverage between both species of donor corals or between their respective controls was determined. The process of filling core holes in donor colonies with concrete plugs was effective, however, tissue did not completely regenerate over the surface of plugs in either species over the relatively short 15-month observation period. Results of this study indicate that species selection is an important factor in the success of coral transplantation

    Growth and Survivorship of Stony Coral Meandrina meandrites and Montastrea cavernosa Transplants to an Artificial Reef Environment: A Work in Progress

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    Reef Ball Deployment: In November of 2000, 160 concrete Reef BallTM modules (1.22m wide x 0.9m high) were deployed, at a depth of approximately 15 meters, between the Second and Third Reef tracts off Dania Beach, FL (Figures 1 and 2). The Reef Balls were grouped into 40 quads, with each quad containing four individual Reef Balls. One modified Reef Ball from each quad was designated as the ‘transplant’ ball, and was used as the receptacle for the coral transplants. The other three balls in each quad are part of a more comprehensive study. This multifactorial study is examining the effects of reef structure on fish assemblages, the effects of coral larval attractants on coral recruitment, and the interaction between fish assemblages and coral recruitment. The coral transplants are one such ‘coral larval attractant’ being examined. Coral transplants, and the donor colonies from which they were obtained, are being monitored for growth and survivorshi

    Total- and Monomethyl-Mercury and Major Ions in Coastal California Fog Water: Results from Two Years of Sampling on Land and at Sea

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    Marine fog water samples were collected over two summers (2014–2015) with active strand collectors (CASCC) at eight coastal sites from Humboldt to Monterey counties in California, USA, and on four ocean cruises along the California coastline in order to investigate mercury (Hg) cycling at the ocean-atmosphere-land interface. The mean concentration of monomethylmercury (MMHg) in fog water across terrestrial sites for both years was 1.6 ± 1.9 ng L-1 (\u3c0.01–10.4 ng L-1, N = 149), which corresponds to 5.7% (2.0–10.8%) of total Hg (HgT) in fog. Rain water samples from three sites had mean MMHg concentrations of 0.20 ± 0.12 ng L-1 (N = 5) corresponding to 1.4% of HgT. Fog water samples collected at sea had MMHg concentrations of 0.08 ± 0.15 ng L-1 (N = 14) corresponding to 0.4% of HgT. Significantly higher MMHg concentrations in fog were observed at terrestrial sites next to the ocean relative to a site 40 kilometers inland, and the mean difference was 1.6 ng L-1. Using a rate constant for photo-demethylation of MMHg of -0.022 h-1 based on previous demethylation experiments and a coastal-inland fog transport time of 12 hours, a mean difference of only 0.5 ng L-1 of MMHg was predicted between coastal and inland sites, indicating other unknown source and/or sink pathways are important for MMHg in fog. Fog water deposition to a standard passive 1.00 m2 fog collector at six terrestrial sites averaged 0.10 ± 0.07 L m-2 d-1, which was ∼2% of typical rainwater deposition in this area. Mean air-surface fog water fluxes of MMHg and HgT were then calculated to be 34 ± 40 ng m-2 y-1 and 546 ± 581 ng m-2 y-1, respectively. These correspond to 33% and 13% of the rain fluxes, respectively

    Developmental mediation of genetic variation in response to the Fast Track Prevention Program

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    We conducted a developmental analysis of genetic moderation of the effect of the Fast Track intervention on adult externalizing psychopathology. The Fast Track intervention enrolled 891 children at high risk to develop externalizing behavior problems when they were in kindergarten. Half of the enrolled children were randomly assigned to receive 10 years of treatment, with a range of services and resources provided to the children and their families, and the other half to usual care (controls). We previously showed that the effect of the Fast Track intervention on participants\u27 risk of externalizing psychopathology at age 25 years was moderated by a variant in the glucocorticoid receptor gene. Children who carried copies of the A allele of the single nucleotide polymorphism rs10482672 had the highest risk of externalizing psychopathology if they were in the control arm of the trial and the lowest risk of externalizing psychopathology if they were in the treatment arm. In this study, we test a developmental hypothesis about the origins of this for better and for worse Gene × Intervention interaction (G × I): that the observed G × I effect on adult psychopathology is mediated by the proximal impact of intervention on childhood externalizing problems and adolescent substance use and delinquency. We analyzed longitudinal data tracking the 270 European American children in the Fast Track randomized control trial with available genetic information (129 intervention children, 141 control group peers, 69% male) from kindergarten through age 25 years. Results show that the same pattern of for better and for worse susceptibility to intervention observed at the age 25 follow-up was evident already during childhood. At the elementary school follow-ups and at the middle/high school follow-ups, rs10482672 predicted better adjustment among children receiving the Fast Track intervention and worse adjustment among children in the control condition. In turn, these proximal G × I effects early in development mediated the ultimate G × I effect on externalizing psychopathology at age 25 years. We discuss the contribution of these findings to the growing literature on genetic susceptibility to environmental intervention

    Developmental mediation of genetic variation in response to the Fast Track Prevention Program

    Get PDF
    We conducted a developmental analysis of genetic moderation of the effect of the Fast Track intervention on adult externalizing psychopathology. The Fast Track intervention enrolled 891 children at high risk to develop externalizing behavior problems when they were in kindergarten. Half of the enrolled children were randomly assigned to receive 10 years of treatment, with a range of services and resources provided to the children and their families, and the other half to usual care (controls). We previously showed that the effect of the Fast Track intervention on participants\u27 risk of externalizing psychopathology at age 25 years was moderated by a variant in the glucocorticoid receptor gene. Children who carried copies of the A allele of the single nucleotide polymorphism rs10482672 had the highest risk of externalizing psychopathology if they were in the control arm of the trial and the lowest risk of externalizing psychopathology if they were in the treatment arm. In this study, we test a developmental hypothesis about the origins of this for better and for worse Gene × Intervention interaction (G × I): that the observed G × I effect on adult psychopathology is mediated by the proximal impact of intervention on childhood externalizing problems and adolescent substance use and delinquency. We analyzed longitudinal data tracking the 270 European American children in the Fast Track randomized control trial with available genetic information (129 intervention children, 141 control group peers, 69% male) from kindergarten through age 25 years. Results show that the same pattern of for better and for worse susceptibility to intervention observed at the age 25 follow-up was evident already during childhood. At the elementary school follow-ups and at the middle/high school follow-ups, rs10482672 predicted better adjustment among children receiving the Fast Track intervention and worse adjustment among children in the control condition. In turn, these proximal G × I effects early in development mediated the ultimate G × I effect on externalizing psychopathology at age 25 years. We discuss the contribution of these findings to the growing literature on genetic susceptibility to environmental intervention

    Can Genetics Predict Response to Complex Behavioral Interventions? Evidence from a Genetic Analysis of the Fast Track Randomized Control Trial

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    Early interventions are a preferred method for addressing behavioral problems in high-risk children, but often have only modest effects. Identifying sources of variation in intervention effects can suggest means to improve efficiency. One potential source of such variation is the genome. We conducted a genetic analysis of the Fast Track randomized control trial, a 10-year-long intervention to prevent high-risk kindergarteners from developing adult externalizing problems including substance abuse and antisocial behavior. We tested whether variants of the glucocorticoid receptor gene NR3C1 were associated with differences in response to the Fast Track intervention. We found that in European-American children, a variant of NR3C1 identified by the single-nucleotide polymorphism rs10482672 was associated with increased risk for externalizing psychopathology in control group children and decreased risk for externalizing psychopathology in intervention group children. Variation in NR3C1 measured in this study was not associated with differential intervention response in African-American children. We discuss implications for efforts to prevent externalizing problems in high-risk children and for public policy in the genomic era
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