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Although the extant literature suggests that associations with deviant peers (ADP) contribute to the persistence and exacerbation of adolescent conduct problems (CP) and substance use (SU), few studies have investigated processes through which these relations develop, the stability of ADP, risk factors for ADP, or prospective relations among patterns of ADP, CP, and SU across adolescence and substance use disorder (SUD) in early adulthood. Relations among ADP with CP and ADP with SU may be due to selection processes (i.e., youth select into ADP groups) and/or socialization processes (youth are influenced by deviant peers once they enter the ADP group). In addition, selection and socialization processes may be moderated by neuropsychological and temperamental (i.e., emotionality) factors, though there is a dearth of literature examining moderators of these processes. The present study addressed these gaps in the literature by examining five research aims: (1) identify subgroups of youth who vary in type and levels of ADP and CP/SU at three different ages using latent class analysis, (2) investigate the stability of ADP and CP/SU subgroup membership using latent transition analysis, (3) examine the prospective relations among ADP and CP/SU subgroup membership, (4) investigate potential neuropsychological and emotion regulation moderators of selection and socialization processes, and (5) evaluate prospective prediction to SUD in early adulthood from patterns of ADP and CP/SU subgroup membership across adolescence. Participants were youth who participated in a large-scale research project conducted through the Center for Education and Drug Abuse Research at the University of Pittsburgh. Youth and their families completed multiple assessments, beginning when youth were 10-12 years old, followed by assessments at 12-14, 16, and 22 years old. Results indicate (a) deviant peer groups vary based on type and severity of deviant behavior; (b) deviant peer group involvement increased across adolescence and continuity of deviant peer involvement was evident; (c) youth selected peers based on similar levels of deviant behavior across ages 10 to 16 years, but were influenced by these deviant peers to engage in CP and/or SU from ages 12-14 to 16 years; (d) relations between youth deviant behaviors and later selection of deviant friends differed according to levels of youth neuropsychological functioning and temperamental emotionality; and (e) earlier involvement with deviant peers, involvement with deviant peer groups defined by severe CP and SU, and youth engagement in both CP and SU were related to the greatest risk for SUD in early adulthood. / Psychology

Fearful temperament represents one of the robust predictors of the development of child and adolescent anxiety. Not all children with fearful temperament unvaryingly develop anxiety, however. Diverse processes resulting from the interplay among attention, cognitive control, and motivational system drive the trajectories toward more adaptive or maladaptive directions. In this study, I examined various factors that underlie the association between fearful temperament at age 9 and adolescent anxiety symptoms including attention biases, different components of effortful control, and frontal EEG asymmetry. 78 children participated in this study. Results indicate that fearful temperament at age 9 significantly predicted adolescent anxiety symptoms. This association, however, was moderated by children's effortful control and frontal EEG asymmetry at age 9. Specifically, fear at 9 years predicted adolescent anxiety only when children had low attentional control, low inhibitory control, low activation control, and exhibited greater right activation from baseline to task. The associations between AB and fearful temperament as well as anxiety were not significant. The association between fear at 9 years and sustained AB during adolescence, however, was moderated by children's attentional control, inhibitory control, and frontal EEG asymmetry at age 9. Specifically, fear predicted attention biases away from threat when children had high attentional control, high inhibitory control, and showed greater left activation. The findings will be discussed in terms of the roles of attention biases in the development of anxiety and how different components of effortful control and frontal EEG asymmetry contribute to the resilience process. / Doctor of Philosophy / Anxiety disorders represent one of the most commonly occurring mental health problems in childhood and adolescence. Children who tend to show wariness and distress to negative stimuli are more likely to have anxiety. Not all children with fearful temperament develop anxiety, however. Certain individual characteristics can protect fearful children from having anxiety symptoms. In this study, I examined the roles of attentional biases toward threat (AB), different components of self-regulation (EC), and the asymmetrical frontal brain activation (FA) in changing the relation between fearful temperament and anxiety. 78 children participated in this study. Results indicated that adolescents were at higher risk for anxiety if they showed high fearful temperament at age 9. However, the risk could be attenuated if children were better able to control their attention and behaviors, and exhibited greater left activation from resting to a mildly stressful situation at age 9. In addition, fearful children were better able to direct attention away from threat during adolescence if they were better able to control their attention and behaviors, and exhibited greater left activation from resting to a mildly stressful situation at age 9. The findings provide suggestions for early identification and intervention of children who are more vulnerable to anxiety during adolescence.

<p dir="ltr">The present study explored the association between maternal use of food to soothe and maternal sensitivity, while considering the potential moderating role of child negative affectivity. Before addressing the key questions, the congruence and stability of key constructs at two different time points, 12 and 18 months, using both self-reported and observer-reported data, were examined. A nonclinical sample of 136 mother-child dyads were recruited. Maternal use of food to soothe, child negative affectivity, and maternal sensitivity were observed across lab visits at both time points, 12 and 18 months. Mothers completed questionnaires about maternal use of food to soothe and child negative affectivity at both time points. Structural Equation Modeling (SEM) was employed to analyze the associations and potential interaction effects between maternal sensitivity and child negative affectivity on maternal use of food to soothe.</p><p dir="ltr">Findings showed that maternal sensitivity was negatively associated with mothers’ use of food to soothe at 12 months in the lab, although this association was not observed at 18 months. Child negative affectivity did not moderate the significant association mentioned. The study also found low to moderate stability in mother-reported use of food to soothe, child negative affectivity, and maternal sensitivity across the two time points. Furthermore, the congruence between self-reported and observer-reported data on these practices was generally low, underscoring the challenges in measuring these behaviors.</p><p dir="ltr">The findings suggest that higher maternal sensitivity could potentially lower the frequency of using food as a soothing method at 12 months. Future research should aim to confirm these findings in more diverse populations and through less structured observational settings.</p>

Uruguay es el séptimo país exportador de carne vacuna del mundo y la producción agropecuaria se realiza mayoritariamente en base a pasturas naturales. Los elevados precios internacionales de la carne y la apertura de nuevos mercados en los últimos años, han provocado la intensificación de los sistemas de engorde. Hoy conviven los sistemas pastoriles tradicionales con los de engorde a corral, pasando por una serie de sistemas intermedios con distinto grado de intensificación. El desafío es mejorar la eficiencia del proceso de producción y la calidad del producto, sin afectar las peculiares características de los sistemas extensivos (bajo costo de producción, calidad nutricional de la carne) y sin comprometer el Bienestar animal y el medio ambiente. Es así que el presente trabajo de tesis pretende caracterizar estas diferentes alternativas de intensificación en lo que se refiere a Bienestar animal y calidad de carne, dado el creciente impacto de ambas temáticas en los precios del producto y en las preferencias de los consumidores de los países destino de las exportaciones. Para ello, se realizaron 2 experimentos en Uruguay durante los años 2005-2006 y 2006-2007, respectivamente. En el primer trabajo se utilizaron 84 novillos de raza Británica asignados a cuatro dietas con niveles incrementales de grano, desde una pradera artificial sin uso de suplemento, hasta un tratamiento de alimentación a corral en base a concentrado y heno. La ganancia de peso de los animales aumentó con el nivel energético de la dieta determinando diferentes fechas de faena para todos los tratamientos. Animales de temperamento más calmo tuvieron mayores ganancias de peso independientemente del nivel de alimentación. Los animales confinados mostraron una mayor dificultad para habituarse a las condiciones de producción, según indicadores fisiológicos relativos al estrés. Dichas dificultades pueden atribuirse en parte a la privación de realizar comportamientos probablemente relevantes para / Campo Gigena, MD. (2009). El bienestar animal y la calidad de carne de novillos en Uruguay con diferentes sistemas de terminación y manejo previo a la faena [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/4326

Given the ubiquity of media use, especially among young children, the current study examines the impact of problematic media use (PMU) on children's (N = 418, M age = 53.62 months, SD = 3.38 months, M and SD are taken from the full sample of 418 children) physiological functioning. With previous studies reporting relations between media use, temperament, and physiological regulation, it was hypothesized that children with greater levels of PMU would have lower levels of baseline respiratory sinus arrhythmia (RSA; a measure of physiological regulatory capacity). It is further hypothesized that, higher levels of negative affect, and lower levels of effortful control (two distinct domains of temperament) would be linked to both PMU and RSA and that temperament might mediate the associations between PMU and physiological regulation (RSA) (i.e., higher negative affect, lower effortful control linked to higher PMU and lower RSA). Data were drawn from Wave 5 of Project M.E.D.I.A, a longitudinal study of the effects of media on children's development. Findings revealed that PMU was significantly linked to lower baseline RSA for girls, but not for boys. Both boys' and girls' PMU was linked to higher levels of negative affect. Girls' PMU was linked to lower effortful control. The hypothesis that temperament would meditate links between PMU and RSA was not supported. The sex difference in the relation between PMU and baseline RSA are discussed, including potential differences in content of media girls are using as well as potential developmental differences for girls' reactivity compared to boys. Overall, PMU may lead to diminished physiological regulation, especially for girls, and appears to be linked to higher levels of negative affect in children. It is important for parents to be aware of the potential impact media use may have on their children's development.

<p dir="ltr">Abstract: Atypical frontal alpha asymmetry is the difference in EEG-measured alpha-band power between right and left hemispheres, and patterns of lateralization are thought to reflect motivational direction (approach/withdrawal) and affective processing. Increased rightward frontal alpha asymmetry is associated with tendency toward approach-related behavior often displayed in attention-deficit/hyperactivity disorder (ADHD), though findings have been inconsistent. While differences in results may be partially accounted for by within-diagnosis heterogeneity, growing evidence suggests individual response tendency and emotional salience of a situation may influence one another. Investigating the potential interactions between trait and state measured variables may therefore clarify lateralization patterns in ADHD. The current study measured frontal alpha asymmetry in a well-characterized sample of school-aged children with and without ADHD. EEG during standard resting-state and emotional passive-viewing tasks were recorded from 220 children (nADHD = 97). A semi-structured clinical interview and standardized rating scales were collected to assign DSM-5 diagnoses and temperament group belonging. Parent measures included the behaviorally-rated Temperament in Middle Childhood Questionnaire (TMCQ). Latent profile analysis within the ADHD group revealed two temperament subgroups: emotionally regulated and emotionally dysregulated (high anger and sadness). EEG assessment suggests children broadly produced a more rightward asymmetry while in resting state compared to a task-based condition, though show no notable differences between neutral and negative emotional task conditions. ADHD diagnostic status, temperament group, and sex assigned at birth did not impact patterns of asymmetry. Results emphasize measurement differences in frontal alpha asymmetry between lab-based tasks and further highlight the importance of state influences on alpha lateralization.</p>