3,461 research outputs found

    Increased mRNA Expression for the α\u3csub\u3e1\u3c/sub\u3e Subunit of the GABA\u3csub\u3eA\u3c/sub\u3e Receptor Following Nitrous Oxide Exposure in Mice

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    The mechanisms by which nitrous oxide (N2O) produces physical dependence and withdrawal seizures are not well understood, but both N2O and ethanol exert some of their effects via the GABAA receptor and several lines of evidence indicate that withdrawal from N2O and ethanol may be produced through similar mechanisms. Expression levels of mRNA transcripts encoding several GABAA receptor subunits change with chronic ethanol exposure and, therefore, we hypothesized that N2O exposure would produce changes in mRNA expression for the α1 subunit. Male, Swiss–Webster mice, 10–12 weeks of age, were exposed for 48 h to either room air or a 75%:25% N2O:O2 environment. Brains were sectioned and mRNA for the a subunit was detected by in situ hybridization using an 35S-labelled cRNA probe. N2O exposure produced a significant increase in expression levels of the α1 subunit mRNA in the cingulate cortex, the CA1/2 region of the hippocampus, the dentate gyrus, the subiculum, the medial septum, and the ventral tegmental area. These results lend support to the hypothesis that N2O effects are produced, at least in part, through the GABAA receptor and that N2O produces these effects through actions in the cingulate cortex, hippocampus, ventral tegmental area and medial septum. These results are also further evidence that ethanol and N2O produce dependence and withdrawal through common mechanisms

    An epidemiological study of burglary offenders: trends and predictors of self-reported arrests for burglary in the United States, 2002-2013

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    Burglary is serious property crime with a relatively high incidence and has been shown to be variously associated with other forms of criminal behavior. Unfortunately, an epidemiological understanding of burglary and its correlates is largely missing from the literature. Using public-use data collected between 2002 and 2013 as part of the National Survey on Drug Use and Health (NSDUH), the current study compared those who self-reported burglary arrest in the prior 12 months with and without criminal history. The unadjusted prevalence estimates of self-reported burglary arrest were statistically different for those with a prior arrest history (4.7%) compared with those without an arrest history (0.02%) which is a 235-fold difference. Those with an arrest history were more likely to report lower educational attainment, to have lower income, to have moved more than 3 times in the past 5 years, and to use alcohol, tobacco, illicit drugs, and engage in binge drinking. Moreover, those with prior arrest histories were younger and more likely to be male. There is considerable heterogeneity among burglars with criminal history indicating substantially greater behavioral risk

    Detection and Mapping of Quantitative Trait Loci that Determine Responsiveness

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    Exposure to 70% N2O evokes a robust antinociceptive effect in C57BL/6 (B6) but not in DBA/2 (D2) inbred mice. This study was conducted to identify quantitative trait loci (QTL) in the mouse genome that might determine responsiveness to N2O. Offspring from the F2 generation bred from B6 and D2 progenitors exhibited a broad range of responsiveness to N2O antinociception as determined by the acetic acid-induced abdominal constriction test. QTL analysis was then used to dissect this continuous trait distribution into component loci, and to map them to broad chromosomal regions. To this end, 24 spleens were collected from each of the following four groups: male and female F2 mice responding to 70% N2O in oxygen with 100% response (high-responders); and male and female F2 mice responding with 0% response (low-responders). Genomic DNA was extracted from the spleens and genotyped with simple sequence length polymorphism MapPairs markers. Findings were combined with findings from the earlier QTL analysis from BXD recombinant inbred mice [Brain Res 725 (1996) 23]. Combined results revealed two significant QTL that influence responsiveness to nitrous oxide on proximal chromosome 2 and distal chromosome 5, and one suggestive QTL on midchromosome 18. The chromosome 2 QTL was evident only in males. A significant interaction was found between a locus on chromosome 6 and another on chromosome 13 with a substantial effect on N2O antinociception

    Lifetime predictions for the Solar Maximum Mission (SMM) and San Marco spacecraft

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    Lifetime prediction techniques developed by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) are described. These techniques were developed to predict the Solar Maximum Mission (SMM) spacecraft orbit, which is decaying due to atmospheric drag, with reentry predicted to occur before the end of 1989. Lifetime predictions were also performed for the Long Duration Exposure Facility (LDEF), which was deployed on the 1984 SMM repair mission and is scheduled for retrieval on another Space Transportation System (STS) mission later this year. Concepts used in the lifetime predictions were tested on the San Marco spacecraft, which reentered the Earth's atmosphere on December 6, 1988. Ephemerides predicting the orbit evolution of the San Marco spacecraft until reentry were generated over the final 90 days of the mission when the altitude was less than 380 kilometers. The errors in the predicted ephemerides are due to errors in the prediction of atmospheric density variations over the lifetime of the satellite. To model the time dependence of the atmospheric densities, predictions of the solar flux at the 10.7-centimeter wavelength were used in conjunction with Harris-Priester (HP) atmospheric density tables. Orbital state vectors, together with the spacecraft mass and area, are used as input to the Goddard Trajectory Determination System (GTDS). Propagations proceed in monthly segments, with the nominal atmospheric drag model scaled for each month according to the predicted monthly average value of F10.7. Calibration propagations are performed over a period of known orbital decay to obtain the effective ballistic coefficient. Progagations using plus or minus 2 sigma solar flux predictions are also generated to estimate the despersion in expected reentry dates. Definitive orbits are compared with these predictions as time expases. As updated vectors are received, these are also propagated to reentryto continually update the lifetime predictions

    Changing perspectives on marijuana use during early adolescence and young adulthood: Evidence from a panel of cross-sectional surveys

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    Introduction. Prior research has often overlooked potential cohort differences in marijuana views and use across adolescence and young adulthood. To begin to address this gap, we conduct an exploratory examination of marijuana views and use among American youth using a panel of cross-sectional surveys. Method. Findings are based on repeated, cross-sectional data collected annually from adolescents (ages 12-17; n = 230,452) and young adults (ages 18-21; n = 120,588) surveyed as part of the National Survey on Drug Use and Health between 2002 and 2014. For each of the birth years between 1986 and 1996, we combined a series of nationally representative cross-sections to provide multi-year data strings designed to approximate nationally representative cohorts. Results. Compared to youth born in the mid-to-late 1980s, youth born in the mid-1990s reported significantly higher levels of marijuana disapproval during the early adolescent years (Age 14: 1988 = 64.7%, 1994 = 70.4%) but lower levels of disapproval during the young adult years (Age 19: 1988 = 32.0%, 1994 = 25.0%; Age 20: 1988 = 27.9%, 1994 = 19.7%). Moreover, the prevalence of marijuana use among youth born in 1994 was significantly lower—compared to youth born in 1988—at age 14 (1988: 11.39%, 1994: 8.19%) and significantly higher at age 18 (1988: 29.67%, 1994: 34.83%). This pattern held even when adjusting for potential confounding by demographic changes in the population across the study period. Conclusions. We see evidence of changes in the perceptions of marijuana use among youth born during the late twentieth century.2018-01-0

    Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids

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    The Challenger disaster and purposeful experiments with liquid hydrogen (H2) and oxygen (Ox) tanks demonstrated that cryogenic H2/Ox fluids always self-ignite in the process of their mixing. Here we propose a cavitation-induced self-ignition mechanism that may be realized under these conditions. In one possible scenario, self-ignition is caused by the strong shock waves generated by the collapse of pure Ox vapor bubble near the surface of the Ox liquid that may initiate detonation of the gaseous H2/Ox mixture adjacent to the gas-liquid interface. This effect is further enhanced by H2/Ox combustion inside the collapsing bubble in the presence of admixed H2 gas

    Uptake of heavy metals, organic trace contaminants and viruses by the Japanese oyster, Crassostrea gigas, grown in a waste recycling aquaculture system : final report

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    A study of 24 weeks duration was carried out in which oysters (Crassostrea gigas) were grown in four regimes. These were: (i) on phytoplankton cultured in a mixture of secondary treated sewage effluent and seawater for a period of 12 weeks followed by a second 12 week period of feeding on phytoplankton cultured in a "clean," inorganically enriched regime; (ii) as for (i) except that the secondary effluent was sand filtered prior to use; (iii) as for (ii) except that the effluent was charcoal filtered prior to use; and (iv) using "clean," inorganically enriched phytoplankton food for the 24 week duration. At intervals of two weeks, populations of oysters were removed for assay for trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) and organic contaminants (hydrocarbons, P . C.B.' s). No significant accumulation or depuration of any metal or organic contaminant was evident in any of the regimes. In terms of these contaminants all oysters are within acceptable edible standards as set by F.D.A. A series of experiments was carried out to examine the public health implications of enterovirus survival in a mollusc culture system fertilized with secondary treated sewage effluent. Using MS-2 bacteriophage and vaccine strain poliovirus it would appear that depuration could be effected in 20-25 days in C. gigas at l5°C. However this does NOT mean that such a time span would be adequate for other enteroviruses. Further work is required in this area.Supported by NOAA Office of Sea Grant, Department of Commerce, Grant No. 04-07-158-44104

    Convergent and discriminant validities of SCBE-30 questionnaire using correlated trait–correlated method Minus One

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    Correlated trait–correlated method minus one was used to evaluate convergent and discriminant validity of Social Competence Behavior Evaluation questionnaire (Social Competence, Anger-Aggression, Anxiety-Withdrawal) between multiple raters. A total of 369 children (173 boys and 196 girls; Mage = 55.85, SDage = 11.54) were rated by their mothers, fathers, and teachers. Results showed more convergence between parents than parent-teacher ratings. Mother-teacher share a common view of child behavior that is not shared with father. Parents had more difficulty distinguishing internalizing and externalizing behaviors (especially fathers). Measurement invariance across child sex was explored, results imply that differences between boys and girls were not due to measure. Girls (compare to boys) were described as more social competent by their fathers and teachers, while boys as more aggressive by mothers and teachers.info:eu-repo/semantics/publishedVersio

    Early father-child and mother-child attachment relationships: contributions to preschoolers’ social competence

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    The main goal of this study was to explore the contributions of early father-child and mother-child attachment relationships to children’s later social competence with their preschool peers; possible unique and shared contributions were tested. Using a multi-method design and focusing on direct observation, attachment was assessed at home at age 3 with the Attachment Behavior Q-sort (AQS) and two years later social competence was assessed at classrooms of 5-year-olds using a set of seven measurement indicators that are part of the Hierarchical Model of Social Competence. Results show that attachment to each parent made unique and significant contributions to children’s social competence and suggested the possibility that each caregiver may have somewhat different patterns of influence on the different indicators of children’s social competence. Findings also suggest the possibility that a secure attachment with one parent may buffer the impact of having an insecure relationship with the other. Due to sample size these results should be seen as a starting point to generate new and larger studies.info:eu-repo/semantics/acceptedVersio

    The iPlant Collaborative: Cyberinfrastructure for Enabling Data to Discovery for the Life Sciences

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    The iPlant Collaborative provides life science research communities access to comprehensive, scalable, and cohesive computational infrastructure for data management; identity management; collaboration tools; and cloud, high-performance, high-throughput computing. iPlant provides training, learning material, and best practice resources to help all researchers make the best use of their data, expand their computational skill set, and effectively manage their data and computation when working as distributed teams. iPlant's platform permits researchers to easily deposit and share their data and deploy new computational tools and analysis workflows, allowing the broader community to easily use and reuse those data and computational analyses
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