621 research outputs found
Examining the factor structure of anxiety and depression symptom items among adolescents in Santiago, Chile
The co-occurrence of emotional disorders among adolescents has received considerable empirical attention. This study aims to contribute to the understanding of co-occurring anxiety and depression by examining the factor structure of the Youth Self-Report used with a sample of low-income adolescents from Santiago, Chile. Data from two independent, randomly selected subsamples were analyzed using exploratory and confirmatory factor analyses. Results indicate the best fit for the data is a two-factor model of anxiety and depression symptoms, which factors anxiety and depression into separate latent constructs. Because the findings show that anxiety and depression are not measured by the same factor in this international sample, the results imply that a valid and useful distinction exists between these constructs. That these constructs are found to be separate factors suggests that anxiety and depression may have separate etiologies and consequences, which might be best addressed by separate intervention components. These findings are consistent with the viewpoint that anxiety and depression constructs have similar emotional features and, despite sharing a common underlying internalizing disorder, distinct items capture aspects of each construct.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140221/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140221/Accepted manuscrip
Personality and parenting processes associated with problem behaviors: a study of adolescents in Santiago, Chile
Considerable research in the U.S. has established that adolescent antisocial, aggressive, and attention problems have a negative influence on adolescents' ability to become productive members of society. However, although these behaviors appear in other cultures, little is known about the development of these problems among adolescents in countries other than the U.S.. This study contributes to our understanding of personality and parenting factors associated with adolescent problem behaviors using an international sample. Data are from a NIDA-funded study of 884 community-dwelling adolescents in Santiago, Chile (Mean age=14, SD=1.4, 48% females) of mid-to-low socioeconomic status. Results revealed that rule-breaking and aggressive behaviors were both associated with greater levels of adolescent drive but lower levels of parental monitoring and positive parenting by both parents. Adolescents who reported more attention problems were more likely to exhibit driven behavior, more behavioral inhibition, to report lower levels of parental monitoring, and positive parenting by mother and father. Results of interactions revealed that the influences of positive parenting and parental monitoring on adolescent aggressive behaviors varied as a function of the gender of the adolescent. Helping parents build on their parenting skills may result in important reductions in adolescent problem behaviors among U.S. and international adolescents.R01 HD033487 - NICHD NIH HHS; R01 DA021181 - NIDA NIH HHS; R01 DA021181-04 - NIDA NIH HH
Gender differences in predictors of self-reported physical aggression: exploring theoretically relevant dimensions among adolescents from Santiago, Chile
Research findings remain unclear on whether different factors predict aggression for adolescent
men and women. Given that aggression research is rarely conducted with Latin American
populations, the current study used multiple imputation and linear regression to assess gender
differences in levels and predictors of self-reported physical aggression among a community
sample of young (ages 11 through 17) men (n=504) and women (n = 471) from Santiago, Chile.
Results revealed that adolescent women reported engaging in higher levels of physical aggression
than men. The variables found to be significantly associated with higher levels of reported
aggression—younger age, less family involvement, less parental control, less positive
relationships with caregivers, having more friends who act out and use substances, having fewer
friends committed to learning, presence of dating violence, and more exposure to neighborhood
crime—were not moderated by gender, implying that similar factors are related to aggression in
adolescent men and women from Chile. Implications for prevention and intervention efforts to
address high-risk adolescents and reduce aggression among Chilean youth are discussed.http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC3876925&blobtype=pdfAccepted manuscrip
Examining the quality of adolescent–parent relationships among Chilean families
The purpose of this study was to examine if adolescents reports of warm and harsh parenting practices by their mothers and fathers varied as a function of demographic, youth and their mothers or mother figures' individual and family characteristics. Data are from 707 community-dwelling adolescents (mean age=14, SD=1.4) and their mothers or mother figures in Santiago, Chile. Having a warmer relationship with both parents was inversely associated with the adolescents' age and positively associated with adolescents' family involvement and parental monitoring. Both mothers' and fathers' harsh parenting were positively associated with adolescent externalizing behaviors and being male and inversely associated with youth autonomy and family involvement. These findings suggest that net of adolescent developmental emancipation and adolescent behavioral problems, positive relationships with parents, especially fathers, may be nurtured through parental monitoring and creation of an interactive family environment, and can help to foster positive developmental outcomes.http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC3839673&blobtype=pdfAccepted manuscrip
Exact multipoint and multitime correlation functions of a one-dimensional model of adsorption and evaporation of dimers
In this work, we provide a method which allows to compute exactly the
multipoint and multi-time correlation functions of a one-dimensional stochastic
model of dimer adsorption-evaporation with random (uncorrelated) initial
states.
In particular explicit expressions of the two-point
noninstantaneous/instantaneous correlation functions are obtained. The
long-time behavior of these expressions is discussed in details and in various
physical regimes.Comment: 6 pages, no figur
Developmental changes in genetic and shared environmental contributions to smoking initiation and subsequent smoking quantity in adolescence and young adulthood
Background Few studies examining the genetic architecture of cigarette smoking have focused on adolescents or examined developmental changes in additive genetic, shared environment and unique environmental influences on liability to initiate cigarette smoking and quantity of cigarettes smoked. The aim of this study is to add to the literature on liability to initiate and use cigarettes during adolescence using a nationally representative sample. Method Data for this study came from adolescent and young adult twin pairs (ages 14-33) from the National Longitudinal Study of Adolescent to Adult Health. We ran a series of developmental causal-contingent-common pathway models to examine whether additive genetic, shared and unique environmental influences on liability to the initiation of cigarette use are shared with those on smoking quantity, and whether their contributions change across development. Results We found evidence for a developmental shift in genetic and shared environmental contributions to cigarette use. Early in adolescence genetic and environmental influences work independently on liability to cigarette smoking initiation and quantity of cigarettes smoked, but liability to these behaviors becomes correlated as individuals age into young adulthood. Conclusions These findings provide insight into the causal processes underlying the liability to smoke cigarettes. With age, there is greater overlap in the genetic and environmental factors that influence the initiation of cigarette smoking and quantity of cigarettes smoked
Cycle by cycle NOx model for diesel engine control
[EN] This paper presents a model for on-line NOx estimation. The method uses both, low frequency components and high frequency components of in-cylinder pressure signal: it harnesses in-cylinder pressure resonance to estimate the trapped mass, and based on this measurement, a NOx model is adapted to estimate NOx emissions cycle by cycle.
In addition of the in-cylinder pressure signal, the procedure only requires from lambda and air mass flow to estimate NOx, so it can give a direct estimation of NOx or improve transient response and aging of current NOx sensors. The method was validated on a CI engine with high pressure EGR loop under steady and transient conditions showing errors below 10% and cycle by cycle time response. (C) 2016 Elsevier Ltd. All rights reserved.Guardiola, C.; MartĂn, J.; Pla, B.; Bares-Moreno, P. (2017). Cycle by cycle NOx model for diesel engine control. Applied Thermal Engineering. 110:1011-1020. doi:10.1016/j.applthermaleng.2016.08.170S1011102011
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