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

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

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

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

Evaluation of ECMWF water vapour fields by airborne differential absorption lidar measurements: a case study between Brazil and Europe

International audienceThree extended airborne Differential Absorption Lidar (DIAL) sections of tropospheric water vapour across the tropical and sub-tropical Atlantic in March 2004 are compared to short-term forecasts of the European Centre for Medium Range Weather Forecasts (ECMWF). The humidity fields between 28° S and 36° N exhibit large inter air-mass gradients and reflect typical transport patterns of low- and mid-latitudes like convection (e.g. Hadley circulation), subsidence and baroclinic development with stratospheric intrusion. These processes re-distribute water vapour vertically such that locations with extraordinary dry/moist air-masses are observed in the lower/upper troposphere, respectively. The mixing ratios range over 3 orders of magnitude. Back-trajectories are used to trace and characterize the observed air-masses. Overall, the observed water vapour distributions are largely reproduced by the short-term forecasts at 0.25° resolution (T799/L91), the correlation ranges from 0.69 to 0.92. Locally, large differences occur due to comparably small spatial shifts in presence of strong gradients. Systematic deviations are found associated with specific atmospheric domains. The planetary boundary layer in the forecast is too moist and to shallow. Convective transport of humidity to the middle and upper troposphere tends to be overestimated. Potential impacts arising from data assimilation and model physics are considered. The matching of air-mass boundaries (transport) is discussed with repect to scales and the representativity of the 2-D sections for the 3-D humidity field. The normalized bias of the model with respect to the observations is 6%, 11% and 0% (moist model biases) for the three along-flight sections, whereby however the lowest levels are excluded

Semi-robotic 6 degree of freedom positioning for intracranial high precision radiotherapy; first phantom and clinical results

<p>Abstract</p> <p>Background</p> <p>To introduce a novel method of patient positioning for high precision intracranial radiotherapy.</p> <p>Methods</p> <p>An infrared(IR)-array, reproducibly attached to the patient via a vacuum-mouthpiece(vMP) and connected to the table via a 6 degree-of-freedom(DoF) mechanical arm serves as positioning and fixation system. After IR-based manual prepositioning to rough treatment position and fixation of the mechanical arm, a cone-beam CT(CBCT) is performed. A robotic 6 DoF treatment couch (HexaPOD™) then automatically corrects all remaining translations and rotations. This absolute position of infrared markers at the first fraction acts as reference for the following fractions where patients are manually prepositioned to within ± 2 mm and ± 2° of this IR reference position prior to final HexaPOD-based correction; consequently CBCT imaging is only required once at the first treatment fraction.</p> <p>The preclinical feasibility and attainable repositioning accuracy of this method was evaluated on a phantom and human volunteers as was the clinical efficacy on 7 pilot study patients.</p> <p>Results</p> <p>Phantom and volunteer manual IR-based prepositioning to within ± 2 mm and ± 2° in 6DoF was possible within a mean(± SD) of 90 ± 31 and 56 ± 22 seconds respectively. Mean phantom translational and rotational precision after 6 DoF corrections by the HexaPOD was 0.2 ± 0.2 mm and 0.7 ± 0.8° respectively. For the actual patient collective, the mean 3D vector for inter-treatment repositioning accuracy (n = 102) was 1.6 ± 0.8 mm while intra-fraction movement (n = 110) was 0.6 ± 0.4 mm.</p> <p>Conclusions</p> <p>This novel semi-automatic 6DoF IR-based system has been shown to compare favourably with existing non-invasive intracranial repeat fixation systems with respect to handling, reproducibility and, more importantly, intra-fraction rigidity. Some advantages are full cranial positioning flexibility for single and fractionated IGRT treatments and possibly increased patient comfort.</p

Reducing Risk for Illicit Drug Use and Prescription Drug Misuse: High School Gay-Straight Alliances and Lesbian, Gay, Bisexual, and Transgender Youth

Previous research suggests that lesbian, gay, bisexual, and transgender (LGBT) youth are at elevated risk for using illicit drugs and misusing prescription drugs relative to heterosexual youth. Previous research also indicates that LGBT youth who attend high schools with a gay-straight alliance (GSA) report having fewer alcohol problems and lower levels of cigarette smoking. The present study investigates whether the absence of a GSA is associated with risk for illicit drug use and prescription drug misuse in a sample of 475 LGBT high school students (M age = 16.79) who completed an online survey. After controlling for demographic variables and risk factors associated with illicit drug use, the results of 12 logistic regression analyses revealed that LGBT youth attending a high school without a GSA evidenced increased risk for using cocaine (adjusted odds ratio [adjOR] = 3.11; 95% confidence interval [95% CI] = 1.23–7.86), hallucinogens (adjOR = 2.59; 95% CI = 1.18–5.70), and marijuana (adjOR = 2.22; 95% CI = 1.37–3.59) relative to peers attending a high school with a GSA. Youth without a GSA also evidenced increased risk for the misuse of ADHD medication (adjOR = 2.00; 95% CI = 1.02–3.92) and prescription pain medication (adjOR = 2.00; 95% CI = 1.10–3.65). These findings extend the research base related to GSAs and further demonstrate the importance of providing LGBT youth with opportunities for socialization and support within the school setting. Important limitations of the present study are reviewed

Ultrathin Tropical Tropopause Clouds (UTTCs) : I. Cloud morphology and occurrence

Subvisible cirrus clouds (SVCs) may contribute to dehydration close to the tropical tropopause. The higher and colder SVCs and the larger their ice crystals, the more likely they represent the last efficient point of contact of the gas phase with the ice phase and, hence, the last dehydrating step, before the air enters the stratosphere. The first simultaneous in situ and remote sensing measurements of SVCs were taken during the APE-THESEO campaign in the western Indian ocean in February/March 1999. The observed clouds, termed Ultrathin Tropical Tropopause Clouds (UTTCs), belong to the geometrically and optically thinnest large-scale clouds in the Earth´s atmosphere. Individual UTTCs may exist for many hours as an only 200--300 m thick cloud layer just a few hundred meters below the tropical cold point tropopause, covering up to 105 km2. With temperatures as low as 181 K these clouds are prime representatives for defining the water mixing ratio of air entering the lower stratosphere

Aerosol analysis and forecast in the European Centre for Medium-Range Weather Forecasts Integrated Forecast System: 2. Data assimilation

This study presents the new aerosol assimilation system, developed at the European Centre for Medium-Range Weather Forecasts, for the Global and regional Earth-system Monitoring using Satellite and in-situ data (GEMS) project. The aerosol modeling and analysis system is fully integrated in the operational four-dimensional assimilation apparatus. Its purpose is to produce aerosol forecasts and reanalyses of aerosol fields using optical depth data from satellite sensors. This paper is the second of a series which describes the GEMS aerosol effort. It focuses on the theoretical architecture and practical implementation of the aerosol assimilation system. It also provides a discussion of the background errors and observations errors for the aerosol fields, and presents a subset of results from the 2-year reanalysis which has been run for 2003 and 2004 using data from the Moderate Resolution Imaging Spectroradiometer on the Aqua and Terra satellites. Independent data sets are used to show that despite some compromises that have been made for feasibility reasons in regards to the choice of control variable and error characteristics, the analysis is very skillful in drawing to the observations and in improving the forecasts of aerosol optical depth

Investigation of chlorine radical chemistry in the Eyjafjallajkull volcanic plume using observed depletions in non-methane hydrocarbons

As part of the effort to understand volcanic plume composition and chemistry during the eruption of the Icelandic volcano Eyjafjallajkull, the CARIBIC atmospheric observatory was deployed for three special science flights aboard a Lufthansa passenger aircraft. Measurements made during these flights included the collection of whole air samples, which were analyzed for non-methane hydrocarbons (NMHCs). Hydrocarbon concentrations in plume samples were found to be reduced to levels below background, with relative depletions characteristic of reaction with chlorine radicals (Cl). Recent observations of halogen oxides in volcanic plumes provide evidence for halogen radical chemistry, but quantitative data for free halogen radical concentrations in volcanic plumes were absent. Here we present the first observation-based calculations of Cl radical concentrations in volcanic plumes, estimated from observed NMHC depletions. Inferred Cl concentrations were between 1.3 × 10 and 6.6 × 10 Cl cm. The relationship between NMHC variability and local lifetimes was used to investigate the ratio between OH and Cl within the plume, with [OH]/[Cl] estimated to be ∼37. Copyright 2011 by the American Geophysical Union