1,018 research outputs found

    Piloted rover technology study

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    This is the May 25, 1990 summary report for Space Transfer Concepts and Analyses (STCA) Study, special study task 9.1, Piloted Rovers Technology Study. Piloted rover concepts, mission scenarios, and the requirements necessary for completion of these missions resulting in the establishment of a lunar base. These tasks were intended to lead to a logical conclusion concerning which piloted rovers technologies are needed to accomplish the various missions, along with a recommended schedule for the development of these technologies

    Discrimination, Distrust, and Racial/Ethnic Disparities in Antiretroviral Therapy Adherence by HIV+ Patients

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    Little is known about the contribution of discriminatory healthcare experiences and healthcare provider distrust to racial/ethnic disparities in antiretroviral adherence among HIV+ patients. Among participants of the national HIV Cost and Services Utilization Study who completed three surveys over 12 months (n = 2267), I examined potential factors associated with discriminatory healthcare experiences and healthcare provider distrust. Among participants who reported antiretroviral therapy use at the last survey (n = 1911), I used structural equation modeling to test direct and indirect relationships among racial/ethnic minority status, discriminatory healthcare experiences, healthcare provider distrust, and medication adherence. I conceptualized minority status as a proxy for experiences with, and expectations about, racism in medicine. Attribution theory and models of antiretroviral therapy adherence informed the hypothesized relationships. Almost half (41%) the participants reported experiencing discrimination in healthcare settings, while few participants reported distrust of their healthcare providers. Factors associated with discrimination were being white (an unexpected finding), younger age, some college education, earlier HIV diagnosis, poorer self-reported physical health, AIDS diagnosis, ever having a CD4 count < 200, any illicit drug use in the past year except heroin or cocaine, and less social support. Factors associated with distrust were younger age, some college education, poorer self-reported physical and mental health, higher viral load, drug use in the past year, less social support, and more discrimination. In the full structural equation model, the direct effect of minority status on adherence remained despite the presence of hypothesized mediators. The magnitude of indirect effects via discrimination, distrust, and medication efficacy beliefs was negligible, and their sum was not statistically significant. The effect of discrimination on adherence was entirely indirect via greater distrust and weaker medication efficacy beliefs. Greater distrust was unexpectedly associated with better adherence. Distrust indirectly affected adherence via participants' psychological distress about taking antiretroviral therapy and weaker medication efficacy beliefs. These findings offer partial support for the relationships posited among experiences and expectations of racism (as racial/ethnic minority status), discriminatory healthcare experiences, healthcare provider distrust, and antiretroviral therapy adherence. Future researchers should consider models with minority status as a contextual influence upon the hypothesized relationships

    The effect of literacy training on the self-concept of moderately mentally handicapped adults

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    In this single group, pretest/posttest design study the literacy level and self-concept of nine moderately mentally handicapped adults was assessed. The participants in the study were involved in reading lessons using the Ball-Stick-Bird reading system, a brainbased program. No significant differences were found in either literacy level or reading level after intervention. However, there were changes in reading behaviour. These changes occurred in the subskills ofdirectionality, letter-sound correspondence, wordreading, and use of reading materials

    An Enhanced Archive Facilitating Climate Impacts and Adaptation Analysis

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    We describe the expansion of a publicly available archive of downscaled climate and hydrology projections for the United States. Those studying or planning to adapt to future climate impacts demand downscaled climate model output for local or regional use. The archive we describe attempts to fulfill this need by providing data in several formats, selectable to meet user needs. Our archive has served as a resource for climate impacts modelers, water managers, educators, and others. Over 1,400 individuals have transferred more than 50 TB of data from the archive. In response to user demands, the archive has expanded from monthly downscaled data to include daily data to facilitate investigations of phenomena sensitive to daily to monthly temperature and precipitation, including extremes in these quantities. New developments include downscaled output from the new Coupled Model Intercomparison Project phase 5 (CMIP5) climate model simulations at both the monthly and daily time scales, as well as simulations of surface hydrologi- cal variables. The web interface allows the extraction of individual projections or ensemble statistics for user-defined regions, promoting the rapid assessment of model consensus and uncertainty for future projections of precipitation, temperature, and hydrology. The archive is accessible online (http://gdo-dcp.ucllnl.org/downscaled_ cmip_projections)

    Exposure to Smoking Imagery in Popular Films and Adolescent Smoking in Mexico

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    Background: Exposure to smoking imagery in films in consistently associated with smoking behavior and its psychological antecedents among adolescents in high-income countries, but its association with adolescent smoking in middle-income countries is unknown. Methods: In 2006, a cross-sectional sample of 3876 Mexican adolescents in secondary school was surveyed on smoking behavior, smoking risk factors, and exposure to 42 popular films that contained smoking. Participants were classified into quartiles of exposure to smoking imagery across all films they reported having seen. Models were estimated to determine associations among quartiles of film-smoking exposure, smoking behavior, and the psychological antecedents of smoking, adjusting for age, gender, sensation seeking, self-esteem, parental smoking, sibling smoking, best-friend smoking, having a bedroom TV, and private versus public school attendance. Analyses were conducted in 2007. Results: Adolescents were exposed to an average of 51.7 (SE=1.3) minutes of smoking in the films they viewed. Crude and adjusting ORs indicated positive associations between quartiles of film-smoking exposure and both current smoking (AOR4v1=3.13; p\u3c0.0001) and having ever smoked (AOR4v1=2.42;p\u3c0.0001). Data from never-smokers (n=2098) were analyzed to determine associations between film-smoking exposure and psychological antecedents of smoking uptake. Crude and adjusted coefficients indicated significant, positive associations between exposure and susceptibility to smoking (AOR4v1=1.66; p\u3c0.05); favorable attitudes toward smoking (Adjusted B4v1=0.44;p\u3c0.0001); and perceived peer prevalence of smoking (Adjusted B4v1=0.26; p\u3c0.0001). Conclusions: Exposure to smoking in films appears associated with smoking among Mexican adolescents. Policies could aim to decrease youth exposure to smoking in nationally and internationally distributed

    Differential Transgene Silencing of Myeloid-Specific Promoters in the AAVS1 Safe Harbor Locus of Induced Pluripotent Stem Cell-Derived Myeloid Cells

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    Targeted integration into a genomic safe harbor, such as the AAVS1 locus on chromosome 19, promises predictable transgene expression and reduces the risk of insertional mutagenesis in the host genome. The application of gamma-retroviral LTR-driven vectors, which semi-randomly integrate into the genome, has previously caused severe adverse events in some clinical studies due to transactivation of neighboring proto-oncogenes. Consequently, the site-specific integration of a therapeutic transgene into a genomic safe harbor locus would allow stable genetic correction with a reduced risk of insertional mutagenesis. However, recent studies revealed that transgene silencing, especially in case of weaker cell type-specific promoters, can occur in the AAVS1 locus of human pluripotent stem cells (PSC) and can impede transgene expression during differentiation. In this study, we aimed to correct p47phox-deficiency, which is the second most common cause of chronic granulomatous disease, by insertion of a therapeutic p47phox transgene into the AAVS1 locus of human induced PSC (iPSC) using CRISPR-Cas9. We analyzed transgene expression and functional correction from three different myeloid-specific promoters (miR223, CatG/cFes and MRP8). Upon myeloid differentiation of corrected iPSC clones, we observed that the miR223 and CatG/cFes promoter achieved therapeutic-relevant levels of p47phox expression and NADPH oxidase activity, whereas the MRP8 promoter was less efficient. Analysis of the different promoters revealed high CpG methylation of the MRP8 promoter in differentiated cells, which correlated with the transgene expression data. In summary, we identified the miR223 and CatG/cFes promoters as cell type-specific promoters that allow stable transgene expression in the AAVS1 locus of iPSC-derived myeloid cells. Our findings further indicate that promoter silencing can occur in the AAVS1 safe harbor locus in differentiated hematopoietic cells and that a comparison of different promoters is necessary to achieve optimal transgene expression for therapeutic application of iPSC-derived cells

    The Bouncing Jet: A Newtonian Liquid Rebounding off a Free Surface

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    We find that a liquid jet can bounce off a bath of the same liquid if the bath is moving horizontally with respect to the jet. Previous observations of jets rebounding off a bath (e.g. Kaye effect) have been reported only for non-Newtonian fluids, while we observe bouncing jets in a variety of Newtonian fluids, including mineral oil poured by hand. A thin layer of air separates the bouncing jet from the bath, and the relative motion replenishes the film of air. Jets with one or two bounces are stable for a range of viscosity, jet flow rate and velocity, and bath velocity. The bouncing phenomenon exhibits hysteresis and multiple steady states.Comment: 9 pages, 7 figures. submitted to Physical Review

    Smokers\u27 Neurological Responses to Novel and Repeated Health Warning Labels (HWLs) From Cigarette Packages

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    Graphic health warning labels (HWLs) depicting bodily injury due to smoking are effective for producing changes in affect, cognition and smoking behavior in adult smokers. However, little is known about the effects of repeated presentation of graphic HWL’s on the aforementioned processes. The goal of this study was to examine neural and behavioral responses to graphic HWL’s and evaluate whether the repeated presentation of graphic HWL’s leads to repetition suppression (RS). Smokers (N = 16) performed an event-related HWL cue task while blood oxygen level dependent (BOLD) signal was collected during a functional magnetic resonance imaging (fMRI) experimental session. Consistent with prior literature, graphic HWL’s, as compared to scrambled images, elicited increased BOLD response in brain regions involved in self-referential and emotion processing. Importantly, BOLD response at sites in this network diminished during repeated presentation of the same HWL. These findings suggest that while novel graphic HWL’smay have a significant effect on smokers’ brain activity, repeated presentationmay lead to muted responses and thus limit their potential to induce behavioral change

    Human Amniocytes Are Receptive to Chemically Induced Reprogramming to Pluripotency

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    Restoring pluripotency using chemical compounds alone would be a major step forward in developing clinical-grade pluripotent stem cells, but this has not yet been reported in human cells. We previously demonstrated that VPA_ AFS cells, human amniocytes cultivated with valproic acid (VPA) acquired functional pluripotency while remaining distinct from human embryonic stem cells (hESCs), questioning the relationship between the modulation of cell fate and molecular regulation of the pluripotency network. Here, we used single-cell analysis and functional assays to reveal that VPA treatment resulted in a homogeneous population of self-renewing non-transformed cells that fulfill the hallmarks of pluripotency, i.e., a short G1 phase, a dependence on glycolytic metabolism, expression of epigenetic modifications on histones 3 and 4, and reactivation of endogenous OCT4 and downstream targets at a lower level than that observed in hESCs. Mechanistic insights into the process of VPA-induced reprogramming revealed that it was dependent on OCT4 promoter activation, which was achieved independently of the PI3K (phosphatidylinositol 3-kinase)/ AKT/ mTOR (mammalian target of rapamycin) pathway or GSK3 beta inhibition but was concomitant with the presence of acetylated histones H3K9 and H3K56, which promote pluripotency. Our data identify, for the first time, the pluripotent transcriptional and molecular signature and metabolic status of human chemically induced pluripotent stem cells
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