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Both parasympathetic nervous system regulation and receipt of social support from close relationships contribute to prosocial development, although few studies have examined their combined influences in adolescence and particularly within racially and ethnically minoritized populations. In this longitudinal study of 229 U.S. Mexican-origin adolescents (48% female-identifying), youths reported on receipt of social support from family and friends from 10 to 16 years, had their baseline respiratory sinus arrhythmia (RSA) measured at 17 years, reported their prosocial behavior and completed the Mind in the Eyes test to assess cognitive empathy at 17 and 19 years, and reported their prosocial civic behavior (i.e., community activity) at 19 years. Family social support predicted prosocial behavior at 17 years, and friend social support predicted prosocial civic behavior at 19 years. Compared to youths with lower or higher baseline RSA, youths with moderate RSA reported more prosocial civic behavior, had greater cognitive empathy, and tended to report more general prosocial behavior at 19 years. The quadratic association between baseline RSA and cognitive empathy was stronger for youths with greater family social support. These findings are the first to extend the evidence that moderate baseline parasympathetic nervous system activity supports prosocial development into late adolescence and with the U.S. Mexican-origin community, and these findings address calls for more integrative biopsychosocial studies of prosociality.

Early exposure to stressful life events is associated with greater risk of chronic diseases and mental health problems, including anxiety. However, there is significant variation in how individuals respond to environmental adversity, perhaps due to individual differences in processing and regulating emotional information. Differences in cognitive control – processes necessary for implementing goal directed behavior – have been linked to both stress exposure and anxiety, but the directionality of these links is unclear. The present study investigated the longitudinal pathway of environmental stress exposure during early adolescence on later adolescent anxiety, and the possible mediating mechanism of cognitive control. Participants were 674 Mexican-origin adolescents (meanage = 10.8 years, 50% male) enrolled in the California Families Project, an ongoing longitudinal study of Mexican-origin families. In the current analysis, we examined self-reports of environmental stressors at age 14 (Time 1), cognitive control at age 16 (Time 2), and anxiety at age 18 (Time 3). Structural equation modeling revealed that environmental stressors (Time 1) had both direct and indirect effects on later anxiety (Time 3) through their effects on cognitive control (Time 2), even when accounting for prior levels of anxiety (Time 2). Cognitive control accounted for 18% of the association between environmental stressors and adolescent anxiety: an increase in stressors decreased cognitive control (β = −0.20, p < 0.001), however, cognitive control buffers against anxiety (β = −0.10, p = 0.004). These findings deepen our understanding of the mechanisms underlying the development of anxiety and highlight the importance of cognitive control as a potential protective factor.

Experiencing poverty during childhood and adolescence may affect brain function. However, income is dynamic, and studies have not addressed whether income change relates to brain function. In the present study, we investigated whether intrinsic functional connectivity of default mode network (DMN) regions was influenced by mean family income and family income change. Parents of 68 Mexican-origin adolescents (35 females) reported family income annually when adolescents were 10–16 years old. Intercept and slope of income at each of these ages were calculated for each participant. At age 16 years, adolescents completed a resting state functional neuroimaging scan. Adolescents from high and low income families did not differ in their functional connectivity, but for adolescents in families with lower incomes, their connectivity patterns depended on their income slope. Low-income adolescents whose income increased demonstrated greater connectivity between the posterior cingulate cortex (PCC) and the medial prefrontal cortex (mPFC), both DMN regions, and between the PCC and the right inferior frontal gyrus. Increases in income were associated with greater connectivity of the mPFC with the right inferior frontal gyrus and the left superior parietal lobule regardless of mean income. Increases in income, especially among adolescents in poverty, may alleviate stressors, influencing the development of brain networks. Keywords: Adversity, Brain, fMRI, Resting state, Socio-economic status, Youth

Loneliness becomes more prevalent as youth transition from childhood into adolescence. A key underlying process may be the puberty-related increase in biological stress reactivity, which can alter social behavior and elicit conflict or social withdrawal (fight-or-flight behaviors) in some youth, but increase prosocial (tend-and-befriend) responses in others. In this article, we propose an integrative theoretical model that identifies the social, personality, and biological characteristics underlying individual differences in social--behavioral responses to stress. This model posits a vicious cycle whereby youth who respond to stress with fight-or-flight tendencies develop increasing and chronic levels of loneliness across adolescence, whereas youth who display tend-and-befriend behaviors may be buffered from these consequences. Based on research supporting this model, we propose multiple avenues for intervention to curtail the prevalence of loneliness in adolescence by targeting key factors involved in its development: social relationships, personality, and stress-induced behavioral and biological changes.

Background: Early adolescent onset of substance use is a robust predictor of future substance use disorders. We examined the relation between age of substance use initiation and resting state functional connectivity (RSFC) of the core reward processing (nucleus accumbens; NAcc) to cognitive control (prefrontal cortex; PFC) brain networks. Method: Adolescents in a longitudinal study of Mexican-origin youth reported their substance use annually from ages 10 to 16 years. At age 16, 69 adolescents participated in a resting state functional magnetic resonance imaging scan. Seed-based correlational analyses were conducted using regions of interest in bilateral NAcc. Results: The earlier that adolescents initiated substance use, the stronger the connectivity between bilateral NAcc and right dorsolateral PFC, right dorsomedial PFC, right pre-supplementary motor area, right inferior parietal lobule, and left medial temporal gyrus. Discussion: The regions that demonstrated significant positive linear relationships between the number of adolescent years using substances and connectivity with NAcc are nodes in the right frontoparietal network, which is central to cognitive control. The coupling of reward and cognitive control networks may be a mechanism through which earlier onset of substance use is related to brain function over time, a trajectory that may be implicated in subsequent substance use disorders.

Sexual debut, or first intercourse, predicts problem behaviors such as substance use. This association could reflect a direct effect of debut itself, general developmental trends, or the fact that some youth are more predisposed to a wide array of problem behaviors (e.g., risky sex, substance use). Understanding the association between sexual debut and substance use thus requires methods that can distinguish between these various accounts. In this study the association between sexual debut and substance use was investigated in a longitudinal sample of Mexican-origin youth (N = 674) assessed annually from 5th (Mage = 10.86 years, SD = 0.51) through 12th grade (Mage = 17.69 years, SD = 0.48). The longitudinal aspect of the data allowed the direct effect of sexual debut on substance use to be tested while accounting for long-term trends in substance use, and stable individual differences in those trends based on early risk and debut timing. Substance use increased over time, and early risk and debut were consistently associated with more substance use. Sexual debut also modestly predicted an increase in substance use after accounting for these effects, however. Taken together, results provide some evidence consistent with each of the potential explanations for the association between sexual debut and substance use across adolescence.

Tomatine was identified as the sole glycoalkaloid of Solanum lycopersicoides leaves. Its quantity in field-grown plants was about 3.2 3.5", of leaf dry matter. This finding gives more evidence of the strong affinity of S. lycopersicoides to the genus Lyropersicon. Furthermore it sugests that this species can be a useful germplasm in tomato breeding

Recent research suggests that the self-conscious emotions of embarrassment, shame, and pride have distinct, nonverbal expressions that can be recognized in the United States at above-chance levels. However, few studies have examined the recognition of these emotions in other cultures, and little research has been conducted in Asia. Consequently the cross-cultural generalizability of self-conscious emotions has not been firmly established. Additionally, there is no research that examines cultural variability in the recognition of the self-conscious emotions. Cultural values and exposure to Western culture have been identified as contributors to variability in recognition rates for the basic emotions; we sought to examine this for the self-conscious emotions using the University of California, Davis Set of Emotion Expressions (UCDSEE). The present research examined recognition of the self-conscious emotion expressions in South Korean college students and found that recognition rates were very high for pride, low but above chance for shame, and near zero for embarrassment. To examine what might be underlying the recognition rates we found in South Korea, recognition of self-conscious emotions and several cultural values were examined in a U.S. college student sample of European Americans, Asian Americans, and Asian-born individuals. Emotion recognition rates were generally similar between the European Americans and Asian Americans, and higher than emotion recognition rates for Asian-born individuals. These differences were not explained by cultural values in an interpretable manner, suggesting that exposure to Western culture is a more important mediator than values.

This study examined factors that relate to academic competence and expectations from elementary to middle school for 674 fifth grade students (50% boys; M age = 10.86 years) of Mexican origin. Models predicting academic competence and expectations were estimated using a Structural Equation Modeling (SEM) framework, with longitudinal data from fifth to eighth grades. School belonging (i.e., social and emotional connectedness to school) predicted greater academic competence and expectations over time. Findings indicate that student feelings of belonging in school may act as a resource that promotes academic competence and expectations. Furthermore, family income, parent education, and generational status had direct effects on academic competence and expectations to some degree, suggesting the importance of contextual factors in this process.