146 research outputs found

    Meteorological modeling sensitivity to parameterizations and satellite-derived surface datasets during the 2017 Lake Michigan Ozone Study

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    High-resolution simulations were performed to assess the impact of different parameterization schemes, surface datasets, and analysis nudging on lower-tropospheric conditions near Lake Michigan. Simulations were performed where climatological or coarse-resolution surface datasets were replaced by high-resolution, real-time datasets depicting the lake surface temperatures (SSTs), green vegetation fraction (GVF), and soil moisture and temperature (SOIL). Comparison of two baseline simulations employing different parameterization schemes (referred to as AP-XM and YNT, respectively) showed that the AP-XM simulation produced more accurate analyses on the outermost 12 km resolution domain but that the YNT simulation was superior for higher-resolution nests. The diurnal evolution of the surface energy fluxes was similar in both simulations on the 12 km grid but differed greatly on the 1.3 km grid where the AP-XM simulation had a much smaller sensible heat flux during the daytime and a physically unrealistic ground heat flux. Switching to the YNT configuration led to more accurate 2 m temperature and 2 m water vapor mixing ratio analyses on the 1.3 km grid. Additional improvements occurred when satellite-derived surface datasets were incorporated into the modeling platform, with the SOIL dataset having the largest positive impact on temperature and water vapor. The GVF and SST datasets also produced more accurate temperature and water vapor analyses but had degradations in wind speed, especially when using the GVF dataset. The most accurate simulations were obtained when using the high-resolution SST and SOIL datasets and analysis nudging above 2 km a.g.l. (above ground level). These results demonstrate the value of using high-resolution satellite-derived surface datasets in model simulations.</p

    Perception of High Alcohol Use of Peers Is Associated With High Personal Alcohol Use in First-Year University Students in Three Central and Eastern European Countries

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    Objectives: The objectives of this study were to assess discrepancies between estimated peer and personal drinking behavior and to determine associations between perceptions of peer and personal drinking behavior among university students from Hungary (HU), Lithuania (LT), and the Slovak Republic (SK). Methods: 2,554 freshman university students completed an online questionnaire on the frequency of their personal alcohol use, the number of heavy drinking occasions and on their perception concerning the corresponding drinking behavior of a typical student. Associations between perceived peer and personal use were analyzed by means of logistic regression, adjusting for sex. Results: The majority of students across all countries thought their peers drink more frequently and are more often involved in heavy drinking occasions than themselves. Students who perceived the frequency of peer alcohol use to be higher were more likely to drink alcohol twice a week or more often (SR: OR = 3.81, 95% CI = 2.51–5.79; LT: OR = 3.16, 95% CI = 2.11–4.75; HU: OR = 2.10, 95% CI = 1.53–2.87) compared with students who drink alcohol monthly or less. Those who perceived the number of peer heavy drinking occasions as high were more likely to report heavy drinking weekly or more often (SR: OR = 3.16, 95% CI = 1.92–5.20; LT:OR = 3.56, 95% CI = 2.14–5.94; HU:OR = 1.41, 95% CI = 0.79–2.51) compared with students who report heavy drinking less than monthly. Conclusions/Importance: University students perceived peer alcohol use to be higher than their personal use. Given the association between perceptions and personal alcohol use, future research should investigate if targeting perceptions in the surveyed countries may have an impact on alcohol use

    Type 2 alveolar cells are stem cells in adult lung

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    Gas exchange in the lung occurs within alveoli, air-filled sacs composed of type 2 and type 1 epithelial cells (AEC2s and AEC1s), capillaries, and various resident mesenchymal cells. Here, we use a combination of in vivo clonal lineage analysis, different injury/repair systems, and in vitro culture of purified cell populations to obtain new information about the contribution of AEC2s to alveolar maintenance and repair. Genetic lineage-tracing experiments showed that surfactant protein C–positive (SFTPC-positive) AEC2s self renew and differentiate over about a year, consistent with the population containing long-term alveolar stem cells. Moreover, if many AEC2s were specifically ablated, high-resolution imaging of intact lungs showed that individual survivors undergo rapid clonal expansion and daughter cell dispersal. Individual lineage-labeled AEC2s placed into 3D culture gave rise to self-renewing “alveolospheres,” which contained both AEC2s and cells expressing multiple AEC1 markers, including HOPX, a new marker for AEC1s. Growth and differentiation of the alveolospheres occurred most readily when cocultured with primary PDGFRα+ lung stromal cells. This population included lipofibroblasts that normally reside close to AEC2s and may therefore contribute to a stem cell niche in the murine lung. Results suggest that a similar dynamic exists between AEC2s and mesenchymal cells in the human lung

    Level of Response to Alcohol as a Factor for Targeted Prevention in College Students

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    BACKGROUND: Heavy alcohol consumption and alcohol problems among college students are widespread and associated with negative outcomes for individuals and communities. Though current methods for prevention and intervention programming have some demonstrated efficacy, heavy drinking remains a problem. A previous pilot study and a recent large scale evaluation (Schuckit et al., 2012; 2015) found that a tailored prevention program based on a risk factor for heavy drinking, low level of response (low LR) to alcohol, was more effective at reducing heavy drinking than a state of the art (SOTA) standard prevention program for individuals with the low LR risk factor. METHODS: The present study enrolled 231 first-semester college freshmen with either high or low LR into the same level of response-based (LRB) or SOTA online prevention programs as in the previous reports (consisting of four weeks of video modules), as well as a group of matched controls not receiving alcohol prevention, and compared changes in alcohol use between these groups across a six-month period. RESULTS: Individuals in alcohol prevention programs had a greater reduction in maximum drinks per occasion and alcohol use disorder symptoms than controls. There was limited evidence for interactions between level of response and prevention group in predicting change in alcohol use behaviors; only among participants with strict adherence to the program was there an interaction between LR and program in predicting maximum drinks per occasion. However, overall, low LR individuals showed greater decreases in drinking behaviors, especially risky behaviors (e.g. maximum drinks, frequency of heavy drinking) than high LR individuals. CONCLUSIONS: These results indicate that prevention programs, including brief and relatively inexpensive web-based programs, may be effective for persons at highest risk for heavier drinking, such as those with a low LR. Tailored programs may provide incremental benefits under some conditions. Long-term follow-ups and further investigations of tailored prevention programs based on other risk factors are needed

    Social norms information for alcohol misuse in university and college students.

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    To determine whether social norms interventions reduce alcohol-related negative consequences, alcohol misuse or alcohol consumption when compared with a control (ranging from assessment only/no intervention to other educational or psychosocial interventions) among university and college students. Search methods The following electronic databases were searched up to May 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (only to March 2008). Reference lists of included studies and review articles were manually searched. Selection criteria Randomised controlled trials or cluster-randomised controlled trials that compared a social normative intervention versus no intervention, alcohol education leaflet or other 'non-normative feedback' alcohol intervention and reported on alcohol consumption or alcohol-related problems in university or college students. Data collection and analysis We used standard methodological procedures as expected by The Cochrane Collaboration. Each outcome was analysed by mode of delivery: mailed normative feedback (MF); Web/computer normative feedback (WF); individual face-to-face normative feedback (IFF); group face-to-face normative feedback (GFF); and normative marketing campaign (MC). Main results A total of 66 studies (43,125 participants) were included in the review, and 59 studies (40,951 participants) in the meta-analyses. Outcomes at 4+ months post intervention were of particular interest to assess when effects were sustained beyond the immediate short term. We have reported pooled effects across delivery modes only for those analyses for which heterogeneity across delivery modes is not substantial (I2 < 50%). Alcohol-related problems at 4+ months: IFF standardised mean difference (SMD) -0.16, 95% confidence interval (CI) -0.31 to -0.01 (participants = 1065; studies = 7; moderate quality of evidence), equivalent to a decrease of 1.5 points in the 69-point alcohol problems scale score. No effects were found for WF or MF. Binge drinking at 4+ months: results pooled across delivery modes: SMD -0.06, 95% CI -0.11 to -0.02 (participants = 11,292; studies = 16; moderate quality of evidence), equivalent to 2.7% fewer binge drinkers if 30-day prevalence is 43.9%. Drinking quantity at 4+ months: results pooled across delivery modes: SMD -0.08, 95% CI -0.12 to -0.05 (participants = 20,696; studies = 33; moderate quality of evidence), equivalent to a reduction of 0.9 drinks consumed each week, from a baseline of 13.7 drinks per week. Drinking frequency at 4+ months: WF SMD -0.12, 95% CI -0.18 to -0.05 (participants = 9456; studies = 9; moderate quality of evidence), equivalent to a decrease of 0.19 drinking days/wk, from a baseline of 2.74 days/wk; IFF SMD -0.21, 95% CI -0.31 to -0.10 (participants = 1464; studies = 8; moderate quality of evidence), equivalent to a decrease of 0.32 drinking days/wk, from a baseline of 2.74 days/wk. No effects were found for GFF or MC. Estimated blood alcohol concentration (BAC) at 4+ months: peak BAC results pooled across delivery modes: SMD -0.08, 95% CI -0.17 to 0.00 (participants = 7198; studies = 13; low quality of evidence), equivalent to a reduction in peak PAC from an average of 0.144% to 0.135%. No effects were found for typical BAC with IFF. Authors' conclusions The results of this review indicate that no substantive meaningful benefits are associated with social norms interventions for prevention of alcohol misuse among college/university students. Although some significant effects were found, we interpret the effect sizes as too small, given the measurement scales used in the studies included in this review, to be of relevance for policy or practice. Moreover, the statistically significant effects are not consistent for all misuse measures, heterogeneity was a problem in some analyses and bias cannot be discounted as a potential cause of these findings
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