6,091 research outputs found

    Should we build more large dams? The actual costs of hydropower megaproject development

    Get PDF
    A brisk building boom of hydropower mega-dams is underway from China to Brazil. Whether benefits of new dams will outweigh costs remains unresolved despite contentious debates. We investigate this question with the "outside view" or "reference class forecasting" based on literature on decision-making under uncertainty in psychology. We find overwhelming evidence that budgets are systematically biased below actual costs of large hydropower dams - excluding inflation, substantial debt servicing, environmental, and social costs. Using the largest and most reliable reference data of its kind and multilevel statistical techniques applied to large dams for the first time, we were successful in fitting parsimonious models to predict cost and schedule overruns. The outside view suggests that in most countries large hydropower dams will be too costly in absolute terms and take too long to build to deliver a positive risk-adjusted return unless suitable risk management measures outlined in this paper can be affordably provided. Policymakers, particularly in developing countries, are advised to prefer agile energy alternatives that can be built over shorter time horizons to energy megaprojects

    Italian Deprivation Index and Dental Caries in 12-Year-Old Children: A Multilevel Bayesian Analysis

    Get PDF
    Evidence from the literature has shown that people with a lower socioeconomic status enjoy less good health than people with a higher socioeconomic status. The Italian deprivation index (DI) was used with the aim to evaluate the association between the DMFT index and risk factors for dental caries, including city population and DI. The study included 4,305 12-year-old children living in 38 cities classified by demographic size as small, midsize and large. Zero-inflated negative binomial multilevel regression models were used to assess risk factors for DMFT and to address excess of zero DMFT and overdispersion through a Bayesian approach. The difference in the average level of DMFT among children living in cities with different DI quintile was not statistically significant (p = 0.578). The DI and ln(population), included as city-level fixed effects in the two-level variance components model, were not statistically significant. Consuming sweet drinks on average increased the mean DMFT of a susceptible child, while having a highly educated mother reduced it. Un-observed heterogeneity among cities was detected for the probability to be non-susceptible to caries (city-level variance = 0.26 with 95% credibility interval 0.09–0.57), while no territorial effect was found for the mean DMFT of the susceptible children. Our results suggest that the DI and city population did not play a role in explaining between-city variability. Interventions against social deprivation can be influential on the perception of oral health in Italian 12-year-old children to the extent that they can also affect individual level factors

    Bayesian Analysis of Doubly Inflated Poisson Regression for Correlated Count Data: Application to DMFT Data

    Get PDF
    Outcome variables in clinical studies sometimes include count data with inflation in two points (usually zero and k (k>0)). Doubly inflated models can be adopted for modeling these types of data. In statistical modeling, the association among subjects due to longitudinal or cluster study designs is considered by random effects models. In this article, we proposed a doubly inflated random effects model using the Bayesian approach for correlated count data with inflation in two values, and compared this model with Bayesian zero-inflated Poisson and Bayesian Poisson models. The parameters’ estimates by these models were obtained by Markov Chain Monte Carlo method using OpenBUGS software. Bayesian models were compared using the deviance information criterion. To this end, we utilized the total number of decayed, missed, and filled teeth of 12-year-old children and also conducted a simulation study.  Results of real data and the simulation study revealed that the proposed model is fitted better than previous models.&nbsp

    Moderation of Sensation Seeking Effects on Adolescent Substance Use

    Get PDF
    abstract: Adolescent substance use carries a considerable public health burden, and early initiation into use is especially problematic. Research has shown that sensation seeking traits increase risk for substance use experimentation, but less is known about individual and contextual factors that can potentially protect against this risk. This study utilized a longitudinal sub sample of youth (N=567) from a larger study of familial alcoholism to examine sensation seeking in early adolescence (ages 10-15) and its relations to later substance use experimentation. Hypotheses tested whether individual executive control, parenting consistency, neighborhood disadvantage, and neighborhood ethnic concentration moderated sensation seeking’s effects on substance use experimentation using multilevel zero-inflated Poisson modeling. Across models, higher levels of sensation seeking were predictive of a higher likelihood of having initiated substance use, but sensation seeking was not significantly related to the number of different substance use classes tried. Only neighborhood disadvantage emerged as a significant moderator of the path from sensation seeking to substance use initiation. The strength of sensation seeking effects on substance use initiation increased as neighborhood disadvantage decreased below average levels, with the most advantaged neighborhoods exhibiting the strongest link between sensation seeking and substance use. There was also a trend towards the most disadvantaged neighborhoods exhibiting increased sensation seeking effects on substance use initiation. These results highlight the importance of focusing on relatively more advantaged areas as potentially risky environments for the externalizing pathway to substance use.Dissertation/ThesisDoctoral Dissertation Psychology 201

    An exploration of how domains of quality of care relate to overall care experience

    Get PDF
    Purpose: To determine the relative influence of the different domains of healthcare quality from the Care Experience Feedback Improvement Tool and identify key predictors of healthcare quality from the patients’ perspective. Measurement is necessary to determine whether quality of healthcare is improving. The Care Experience Feedback Improvement Tool was developed as a brief measure of patient experience. It is important to determine the relative influence of the different domains of healthcare quality to further clarify how the Care Experience Feedback Improvement Tool can be used and identify key predictors of healthcare quality from the patients’ perspective. Methods: 802 people with a healthcare experience during the previous 12 months were telephoned to complete the Care Experience Feedback Improvement Tool questions and an additional eleven-point global rating of patient experience. To estimate the influence of different domains of healthcare quality on patient overall ratings of quality of healthcare experience, we regressed the overall rating of patient experience with each component of quality (safety, effectiveness, timely, caring, enables system navigation and person-centred). Findings: We found that all of the domains of the Care Experience Feedback Improvement Tool, influenced patient experience ratings of healthcare quality. Specifically, results show the degree of influence, the impact of demographics and how high scores for overall rating of patient experience can be predicted. Originality: Our findings suggest that all of the Care Experience Feedback Improvement Tool domains are important in terms of capturing the wholeness of the patient experience of healthcare quality to direct local quality improvement

    Both Trait and State Mindfulness Predict Lower Aggressiveness via Anger Rumination: a Multilevel Mediation Analysis

    Get PDF
    Trait mindfulness, or the capacity for nonjudgmental, present-centered attention, predicts lower aggression in cross-sectional samples, an effect mediated by reduced anger rumination. Experimental work also implicates state mindfulness (i.e., fluctuations around one's typical mindfulness) in aggression. Despite evidence that both trait and state mindfulness predict lower aggression, their relative impact and their mechanisms remain unclear. Higher trait mindfulness and state increases in mindfulness facets may reduce aggression-related outcomes by (1) limiting the intensity of anger, or (2) limiting rumination on anger experiences. The present study tests two hypotheses: First, that both trait and state mindfulness contribute unique variance to lower aggressiveness, and second, that the impact of both trait and state mindfulness on aggressiveness will be uniquely partially mediated by both anger intensity and anger rumination. 86 participants completed trait measures of mindfulness, anger intensity, and anger rumination, then completed diaries for 35 days assessing mindfulness, anger intensity, anger rumination, anger expression, and self-reported and behavioral aggressiveness. Using multilevel zero-inflated regression, we examined unique contributions of trait and state mindfulness facets to daily anger expression and aggressiveness. We also examined the mediating roles of anger intensity and anger rumination at both trait and state levels. Mindfulness facets predicted anger expression and aggressiveness indirectly through anger rumination after controlling for indirect pathways through anger intensity. Individuals with high or fluctuating aggression may benefit from mindfulness training to reduce both intensity of and rumination on anger

    An Analysis of Race and Ethnicity Patterns in Boston Police Department Field Interrogation, Observation, Frisk, and/or Search Reports

    Get PDF
    The report, authored by researchers from Columbia, Rutgers and the University of Massachusetts, analyzed 200,000+ encounters between BPD officers and civilians from 2007–2010. It is intended to provide a factual basis to assess the implementation of proactive policing in Boston and how it affects Boston's diverse neighborhoods. It found racial disparities in the Boston Police Department's stop-and-frisks that could not be explained by crime or other non-race factors. Blacks during that period were the subjects of 63.3% of police-civilian encounters, although less than a quarter of the city's population is Black.

    Concentration of personal and household crimes in England and Wales

    Get PDF
    Crime is disproportionally concentrated in few areas. Though long-established, there remains uncertainty about the reasons for variation in the concentration of similar crime (repeats) or different crime (multiples). Wholly neglected have been composite crimes when more than one crime types coincide as parts of a single event. The research reported here disentangles area crime concentration into repeats, multiple and composite crimes. The results are based on estimated bivariate zero-inflated Poisson regression models with covariance structure which explicitly account for crime rarity and crime concentration. The implications of the results for criminological theorizing and as a possible basis for more equitable police funding are discussed

    Alcohol Availability and Violence among Inner‐City Adolescents: A Multi‐Level Analysis of the Role of Alcohol Outlet Density

    Full text link
    Researchers recognize that the connection between alcohol and peer violence may relate to community level ecological factors, such as the location of businesses that sell alcohol. Building on previous research among adults, this study examines the relationship between alcohol outlet density and violent behaviors among adolescents, taking into account demographic characteristics, individual alcohol use, and neighborhood level socioeconomic indicators. Data drawn from a diverse Emergency Department based sample of 1,050 urban adolescents, combined with tract level data from the state liquor control commission and U.S. Census, were analyzed. Results of multivariate multi‐level regression analysis indicate that alcohol outlet density is significantly related to adolescents' violent behaviors, controlling for demographic characteristics and individual alcohol use. Census tract level socioeconomic indicators were not significantly associated with youth violence. Findings suggest that alcohol outlet density regulation should be considered as part of broader violence prevention strategies for urban adolescents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117032/1/ajcp9353.pd

    Evaluating the Effect of Socio-Economic Status on DMFT Index in Children Aged 12 in Iran through Zero-Inflated Poisson Regression

    Get PDF
    Introduction: The most common index in dental studies is the decayed, missing, or filled teeth (dmft)/DMFT. Risk factor evaluation in order to investigate the significant factors that affect this DMFT in children has an important role in dental epidemiological studies. The aim of this study was to investigate the association between socioeconomic factors and dental caries. Materials and Methods:  This cross-sectional study was a part of a national survey for assessing the oral health status of Iranian citizens in 2012. The target population was children aged. The data and oral examination results were collected by the clinical examination form and trained calibrated dental group (dentists and hygienists). A zero-inflated Poisson regression model (ZIP) with a random effect was utilized for evaluating the effect of socioeconomic status on DMFT. Results:  In general, 1564 subjects were studied. From the entire subject in this study, the frequency of zero was 4176 (67%). The result of the ZIP model with random effect in zero part showed that socioeconomic status (OR = 1.97; P-value <0.001) had a significant effect on zero DMFT occurrences. The variance component of the random intercept in zero part was significant too (σ2 =17.11, P < 0.001). Conclusion: The zero-inflated Poisson model with random effect in zero part was fitted to this data. Children from lower socioeconomic classes experienced more DMFT. &nbsp
    • 

    corecore