11,185 research outputs found

    The Role of Personality in Predicting Drug and Alcohol Use Among Sexual Minorities

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    Research consistently demonstrates that sexual minority status is associated with increased risk of problematic substance use. Existing literature in this area has focused on group-specific minority stress factors (e.g., victimization and internalized heterosexism). However, no known research has tested the incremental validity of personality traits as predictors of substance use beyond identified group-specific risk factors. A sample of 704 sexual minority adults was recruited nationally from lesbian, gay, bisexual, transgender, queer, and questioning community organizations and social networking Web sites and asked to complete an online survey containing measures of personality, sexual minority stress, and substance use. Hierarchical regression models were constructed to test the incremental predictive validity of five-factor model personality traits over and above known sexual minority risk factors. Consistent with hypotheses, extraversion and conscientiousness were associated with drug and alcohol use after accounting for minority stress factors, and all factors except agreeableness were associated with substance use at the bivariate level of analysis. Future research should seek to better understand the role of normal personality structures and processes conferring risk for substance use among sexual minorities

    Ecological Momentary Assessment of Daily Discrimination Experiences and Nicotine, Alcohol, and Drug Use Among Sexual and Gender Minority Individuals

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    Objective: Sexual and gender minority (SGM) individuals experience elevated rates of minority stress, which has been linked to higher rates of nicotine and substance use. Research on this disparity to date is largely predicated on methodology that is insensitive to within day SGM-based discrimination experiences, or their relation to momentary nicotine and substance use risk. We address this knowledge gap in the current study using ecological momentary assessment (EMA). Method: Fifty SGM individuals, between 18 and 45 years of age, were recruited from an inland northwestern university, regardless of their nicotine or substance use history, and invited to participate in an EMA study. Each were prompted to provide data, six times daily (between 10:00 a.m. and 10:00 p.m.) for 14 days, regarding SGM-based discrimination, other forms of mistreatment, and nicotine, drug, and alcohol use since their last prompt. Results: Discrimination experiences that occurred since individuals’ last measurement prompt were associated with greater odds of nicotine and substance use during the same measurement window. Substance use was also more likely to occur in relation to discrimination reported two measurements prior in lagged models. Relative to other forms of mistreatment, discrimination effects were consistently larger in magnitude and became stronger throughout the day/evening. Conclusion: This study adds to existing minority stress research by highlighting the both immediate and delayed correlates of daily SGM-based discrimination experiences. These results also contribute to our understanding of daily stress processes and provide insight into ways we might mitigate these effects using real-time monitoring and intervention technology

    Failure mechanisms of graphene under tension

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    Recent experiments established pure graphene as the strongest material known to mankind, further invigorating the question of how graphene fails. Using density functional theory, we reveal the mechanisms of mechanical failure of pure graphene under a generic state of tension. One failure mechanism is a novel soft-mode phonon instability of the K1K_1-mode, whereby the graphene sheet undergoes a phase transition and is driven towards isolated benzene rings resulting in a reduction of strength. The other is the usual elastic instability corresponding to a maximum in the stress-strain curve. Our results indicate that finite wave vector soft modes can be the key factor in limiting the strength of monolayer materials

    Sexual Minority Stress and Suicide Risk: Identifying Resilience through Personality Profile Analysis

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    Sexual minority-based victimization, which includes threats or enacted interpersonal violence, predicts elevated suicide risk among sexual minority individuals. However, research on personality factors that contribute to resilience among sexual minority populations is lacking. Using the Five-Factor Model, we hypothesized that individuals classified as adaptive (vs. at-risk) would be at decreased risk for a suicide attempt in the context of reported lifetime victimization. Sexual minority-identified young adults between the ages of 18 and 25 years (N = 412) were recruited nationally and asked to complete an online survey containing measures of personality, sexual minority stress, and lifetime suicide attempts. A 2-stage cluster analytic method was used to empirically derive latent personality profiles and to classify respondents as adaptive (lower neuroticism and higher extroversion, agreeableness, conscientiousness, and openness) or at-risk (higher neuroticism, lower extroversion, agreeableness, conscientiousness, and openness) on the basis of their Five-Factor Personality trait scores. Adaptive individuals were slightly older and less likely to conceal their sexual orientation, but they reported similar rates of victimization, discrimination, and internalized heterosexism as their at-risk counterparts. Logistic regression results indicate that despite reporting similar rates of victimization, which was a significant predictor of lifetime suicide attempt, adaptive individuals evidenced decreased risk for attempted suicide in the context of victimization relative to at-risk individuals. These findings suggest that an adaptive personality profile may confer resilience in the face of sexual minority-based victimization. This study adds to our knowledge of sexual minority mental health and highlights new directions for future research

    The CN Isotopic Ratios In Comets

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    Our aim is to determine the isotopic ratios (12)C/(13)C and (14)N/(15)N in a variety of comets and link these measurements to the formation and evolution of the solar system. The (12)C/(13)C and (14)N/(15)N isotopic ratios are measured for the CN radical by means of high-resolution optical spectra of the R branch of the B-X (0, 0) violet band. 23 comets from different dynamical classes have been observed, sometimes at various heliocentric and nucleocentric distances, in order to estimate possible variations of the isotopic ratios in parent molecules. The (12)C/(13)C and (14)N/(15)N isotopic ratios in CN are remarkably constant (average values of, respectively, 91.0 +/- 3.6 and 147.8 +/- 5.7) within our measurement errors, for all comets whatever their origin or heliocentric distance. While the carbon isotopic ratio does agree with the terrestrial value (89), the nitrogen ratio is a factor of two lower than the terrestrial value (272), indicating a fractionation in the early solar system, or in the protosolar nebula, common to all the comets of our sample. This points towards a common origin of the comets independently of their birthplaces, and a relationship between HCN and CN.NSFAstronom

    Spitzer observations of the Hyades: Circumstellar debris disks at 625 Myr of age

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    We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160 micron due to debris disks around a sample of 45 FGK-type members of the Hyades cluster. We supplement our observations with archival 24 and 70 micron Spitzer data of an additional 22 FGK-type and 11 A-type Hyades members in order to provide robust statistics on the incidence of debris disks at 625 Myr of age an era corresponding to the late heavy bombardment in the Solar System. We find that none of the 67 FGK-type stars in our sample show evidence for a debris disk, while 2 out of the 11 A-type stars do so. This difference in debris disk detection rate is likely to be due to a sensitivity bias in favor of early-type stars. The fractional disk luminosity, L_dust/L*, of the disks around the two A-type stars is ~4.0E-5, a level that is below the sensitivity of our observations toward the FGK-type stars. However, our sensitivity limits for FGK-type stars are able to exclude, at the 2-sigma level, frequencies higher than 12% and 5% of disks with L_dust/L* > 1.0E-4 and L_dust/L* > 5.0E-4, respectively. We also use our sensitivity limits and debris disk models to constrain the maximum mass of dust, as a function of distance from the stars, that could remain undetected around our targets.Comment: 33 pages, 11 figures, accepted by Ap

    Response of Spring Barley (Hordeum vulgare) to Herbicides

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    ‘Karla’, ‘Klages\u27, ‘Morex’, and ‘Steptoe’ cultivars of spring barley (Hordeum vulgare L.) differed in susceptibility to postemergence recommended application rates of diclofop {(±)-2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid}, difenzoquat [1,2-dimethyl-3,5-diphenyl-1H-pyrazolium], chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide}, and metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] in 1981 and 1982. Metribuzin injured Morex, and difenzoquat injured all cultivars within 2 weeks after herbicide application. Metribuzin reduced height and crop biomass compared to the hand-weeded control. Herbicide treatments did not affect grain yield at Moscow, ID, in either year. However, metribuzin reduced yield of Karla and Morex, and diclofop reduced yield of Karla compared to the hand-weeded control at Pullman, WA, in 1982. Barley injury and grain yield loss depended on herbicide treatment and cultivar. Early season herbicide injury to barley did not indicate grain yield response at harvest

    Statistical analysis on testing of an entangled state based on Poisson distribution framework

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    A hypothesis testing scheme for entanglement has been formulated based on the Poisson distribution framework instead of the POVM framework. Three designs were proposed to test the entangled states in this framework. The designs were evaluated in terms of the asymptotic variance. It has been shown that the optimal time allocation between the coincidence and anti-coincidence measurement bases improves the conventional testing method. The test can be further improved by optimizing the time allocation between the anti-coincidence bases.Comment: This paper is an extended version of the theoretical part of v1 of quant-ph/0603254.quant-ph/0603254 is revised so that it is more familiar to experimentalist

    Large excess of heavy nitrogen in both hydrogen cyanide and cyanogen from comet 17P/Holmes

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    From millimeter and optical observations of the Jupiter-family comet 17P/Holmes performed soon after its huge outburst of October 24, 2007, we derive 14 N/15N = 139 +/- 26 in HCN, and 14N/15N = 165 +/- 40 in CN, establishing that HCN has the same non-terrestrial isotopic composition as CN. The same conclusion is obtained for the long-period comet C/1995 O1 (Hale-Bopp) after a reanalysis of previously published measurements. These results are compatible with HCN being the prime parent of CN in cometary atmospheres. The 15N excess relative to the Earth atmospheric value indicates that N-bearing volatiles in the solar nebula underwent important N isotopic fractionation at some stage of Solar System formation. HCN molecules never isotopically equilibrated with the main nitrogen reservoir in the solar nebula before being incorporated in Oort-cloud and Kuiper-belt comets. The 12C/13C ratios in HCN and CN are measured to be consistent with the terrestrial value.Comment: Accepted for publication in the Astrophysical Journal (Letters) 4 page
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