Background: Despite existing literature on the link between bullying victimization and psychological well-being, little is known about the potential lasting negative effects of chronic bullying victimization, especially among children from multicultural families (CMF). Objective: This study examined the longitudinal association between chronic bullying victimization and life satisfaction among CMF in Korea, and further investigated whether this association differs by immigrant mothers' country of origin. Participants and setting: This study utilized data from the Multicultural Adolescents Panel Study (MAPS) 2011-2019, a nationally representative longitudinal study of CMF in Korea who were between the ages of 9 and 12 at baseline (N = 1375). Methods: Fixed effects models were employed to address potential bias resulting from unobserved time-invariant confounders. Three theoretical models were proposed to examine the trajectory patterns of change in life satisfaction among chronically bullied children: cumulative effects, immediate-sustained effects, and short-lived effects models. Results: The longitudinal trajectories of change in life satisfaction associated with chronic bullying victimization were consistent with an immediate-sustained effects model. Heterogeneous patterns in the association by mothers' country of origin were observed. A cumulative effects model was supported for children with Southeast Asian mothers, indicating that chronic bullying victimization leads to a cumulative decrease in life satisfaction. For children with Chinese and Japanese mothers, the results supported either immediate-sustained or short-lived effects models. Conclusions: Efforts to improve the psychological well-being of CMF should consider the potential long-term risk of chronic bullying victimization, particularly among youth with mothers from Southeast Asia.

BackgroundWhile prior literature has documented the impact of housing quality on health, the long-lasting effects of poor housing conditions in adolescence on adult health remain understudied. This study employs an outcome-wide longitudinal approach to estimate the association between poor housing conditions in adolescence and a set of health outcomes in adulthood.MethodsData from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a large-scale, nationally representative sample of US adolescents, were used. This study analysed 15 health outcomes encompassing physical and mental/cognitive health, and health behaviours. The Bonferroni correction was applied to adjust the significance level of multiple testing of the associations.ResultsAfter applying the Bonferroni correction, poor housing conditions in adolescence were associated with seven adult health outcomes. These conditions were particularly strongly and robustly linked to mental health issues, including depression, suicidal ideation and perceived stress. Additionally, poor housing conditions were related to physical health outcomes such as cardiovascular disease risk and self-rated health, as well as health behaviours such as smoking and unhealthy eating behaviour.ConclusionPoor housing conditions during adolescence can act as an early risk factor for adult health, particularly mental health. These findings support the adoption of a life course approach and strengthen the case for housing interventions aimed at improving health outcomes.

Objectives: Over the past three decades, the number of multicultural families in Korea, defined as a family consisting of a native Korean and a marriage immigrant, has increased significantly. Although bullying victimization among multicultural family youth is rightfully a growing concern, less is known about the effects bullying has on immigrant mothers of children who have been bullying victims. Method: Using data from the Multicultural Adolescents Panel Study, this study investigates whether children's bullying victimization is associated with immigrant mothers' acculturative stress and whether this association differs depending on mothers' country of origin (China, Japan, and Southeast Asian countries). Results: Fixed effects estimates revealed that children's bullying victimization is positively associated with their immigrant mother's acculturative stress, and this association is robust to controlling for unobserved time-constant individual-level heterogeneity. When stratified by mother's country of origin, the association was larger and statistically significant only among Southeast Asian mothers. No associations were observed among Japanese and Chinese mothers. Conclusions: Our findings suggest that interventions aiming to support bullied children should be expanded to also support their immigrant mothers. Policymakers may wish to consider the specific backgrounds and contexts of immigrant mothers, with special attention to Southeast Asian women.

Despite the growing evidence on the influence of neighborhood safety on physical activity, few studies have specifically focused on preschool-aged children and differentiated the various domains of neighborhood safety. This study investigates the relationship between parental perceptions of neighborhood safety and preschool children’s time spent outdoors and explores potential sex differences in this relationship. This study analyzed nationally representative data from 1,656 Korean children (848 boys and 808 girls) aged 3, 5, 6 years collected over the course of three waves of the Panel Study on Korean Children (PSKC). Outdoor playtime was measured by maternal reports of the time their children spent playing outdoors on a typical weekday. Parental perceptions of neighborhood safety were assessed using two items that inquired about neighborhood safety in terms of crime and accidents, respectively. Fixed effects estimates revealed that parental perceptions of social safety were associated with an increase in children’s outdoor physical activity (b = 3.778, p < 0.05), whereas perceptions of physical safety were not. Sex-stratified models showed that the association between parental perceptions of social safety and children’s outdoor play was driven largely by boys (b = 8.498, p < 0.001), with no association observed for girls. The findings of this study underscore the importance of addressing the social safety of neighborhood environments to promote outdoor play in preschool children. Moreover, sex differences should be considered when developing interventions aimed at increasing physical activity among young children.

Despite the well-established link between adolescent learning disabilities (LD) and mental health, little is known about its long-term consequences. This study examines the relationship between adolescent LD and adult depressive symptoms, with a focus on gender differences and underlying mechanisms. Using a sibling sample from the National Longitudinal Study of Adolescent to Adult Health (N = 3,414), this study estimated sibling fixed effects models to account for unobserved family-level characteristics such as genes and early childhood family and social context. Sobel mediation analyses were conducted to examine social-psychological mechanisms, including the student-teacher relationship, the student-student relationship, and a sense of school belonging. LD in adolescence was positively associated with depressive symptoms in adulthood (b = 0.823, p < 0.05). This association remained robust when controlling for unobserved family-level confounders as well as educational attainment in adulthood. Gender-stratified models showed that only the association for women is statistically significant (b = 1.935, p < 0.05), and its magnitude is nearly three times that of the association for men. Sobel mediation tests indicate that a decline in a sense of school belonging mediates approximately 17% of the association between adolescent LD and adult depressive symptoms. This study's findings suggest that LD in adolescence is associated with an increase in depressive symptoms in adulthood, particularly in women, and a low sense of school belonging may be a potential mediator. Implementing interventions to improve the school integration of girls with LD could be an effective means of improving their long-term mental health.

Child welfare and protection are of importance in low- and middle-income countries, yet parental physical violence (PPV) towards children is still widespread in Vietnam. Despite existing research on the adverse consequences of PPV, there is a lack of evidence from developing countries, particularly regarding its peer effects. This study investigated the association between class-level exposure to PPV and an individual student's risk of bullying victimization. Potential gender differences in the association were also examined. This study utilized nationally representative data from the Young Lives: School Survey, Vietnam, 2011-2012 (YLSSV 2011-2012) (N = 2,508). This study leveraged quasi-exogenous variation arising from the random assignment of students to classes by employing school fixed effects models. The results of this study showed a significant positive association between a higher proportion of classmates exposed to PPV and an individual student's risk of bullying victimization. This association remained significant even after adjusting for individual-level exposure to PPV and a variety of individual- and class-level covariates. Gender-stratified analyses revealed that PPV among male peers (but not female peers) is significantly associated with bullying victimization risk for both boys and girls. The findings of this study highlight that the negative impacts of violent parenting practices extend beyond the directly affected children, influencing their peers as well. This emphasizes the importance of protecting students from physical violence in the home environment.

IntroductionChildren from multicultural families in South Korea are at high risk of bullying victimization, highlighting the need for a deeper understanding of the challenges they face. This study explores the gendered dynamics of depressive symptoms associated with persistent exposure to bullying victimization among these youths, as well as the role of family support.MethodsThis study utilizes data from nine waves of the Multicultural Adolescents Panel Study (MAPS), spanning from 2011 (Wave 1) to 2019 (Wave 9). MAPS is a nationally representative longitudinal survey of adolescents with multicultural backgrounds and their mothers. Participants include 1375 families (51.1% girls; grade 4-13). Fixed-effects models were estimated to address the possibility of bias due to unobserved time-invariant confounders. Gender-stratified analyses and interaction models were employed to examine the moderating role of gender and family support.ResultsDepressive symptoms among girls were higher with persistent bullying victimization; however, this association was observed up to two consecutive waves of exposure (an immediate and short-term pattern). In contrast, persistent bullying victimization was associated with a cumulative increase in depressive symptoms up to three or more consecutive waves of exposure in boys (an immediate and cumulative pattern). Moreover, while family support was associated with lower levels of depressive symptoms among bullied girls, bullied boys exhibited a similar pattern of a cumulative increase in depressive symptoms regardless of the level of family support.ConclusionThe study's findings suggest potential considerations for gendered interventions related to mental health outcomes of bullying victimization among multicultural family youth in Korea.

Rationale: Children from multicultural families in Korea are vulnerable to bullying victimization. Despite growing evidence on the mental health consequences of bullying victimization for victims, little is known about the spillover effects on their immigrant mothers. Objective: This study examined the association between children's bullying victimization and their immigrant mothers' suicidal ideation. The potential moderating role of family socioeconomic status was also investigated. Methods: Using nine waves of the Multicultural Adolescents Panel Study spanning from 2011 to 2019 (N =1466), this study estimated individual fixed effects models to control for unobserved individual-level heterogeneity. Interaction models were used to investigate potential heterogeneity by family socioeconomic status, including maternal education, household income, and maternal occupational status. Results: Fixed effects estimates revealed that children's bullying victimization is associated with an increased likelihood of suicidal ideation among marriage migrant mothers (b = 0.012, p < 0.05), even after controlling for unobserved time-invariant confounders as well as a set of time-varying covariates. Family socioeconomic status moderated this association. The association between children's bullying victimization and immigrant mothers' suicidal ideation was stronger for those with low levels of education and household income. No such moderating effects were observed for maternal occupation. Conclusions: The findings of this study suggest that efforts to address the mental health consequences of bullying victimization among multicultural family children should extend beyond the victim to their immigrant mothers. When developing interventions to reduce suicidal ideation among immigrant mothers whose children have been victimized, policymakers may wish to consider the moderating role of family socioeconomic status.

Purpose: The purpose of this study is to examine the association between classmates' discrimi-nation experiences and an individual student's depressive symptoms. A set of social-psychological and behavioral variables were considered as potential mechanisms underlying this association.Methods: The data came from the Gyeonggi Education Panel Study of seventh graders in South Korea. This study leveraged quasi-experimental variation generated from random assignment of students to classes within schools to address the endogenous school selection problem and ac-count for the unobserved school-level confounders. To formally test for mediation, Sobel tests were conducted and peer attachment, school satisfaction, smoking, and drinking were explored as mechanism variables.Results: An increase in classmates' discrimination experiences was positively associated with an individual student's depressive symptoms. This association remained statistically significant even after adjusting for personal discrimination experience, a myriad of individual-and class-level covariates, as well as school fixed effects (b = 0.325, p < .05). Classmates' discrimination experi-ences were also associated with a decline in peer attachment and school satisfaction (b = -0.386, p < .01 and b = -0.399, p < .05, respectively). These psychosocial factors explained about one-third of the association between classmates' discrimination experiences and individual students' depressive symptoms.Discussion: The findings of this study suggest that exposure to peer-level discrimination experi-ence leads to friend detachment and school dissatisfaction, which in turn increases an individual student's depressive symptoms. This study reaffirms the importance of fostering a more cohesive and nondiscriminatory school environment to promote adolescents' psychological health and well-being.(c) 2023 Society for Adolescent Health and Medicine. All rights reserved.

PURPOSE:This study aims to examine the association between bullying victimization and depressive symptoms among youth from multicultural families in Korea, while distinguishing between the effects of entering and exiting bullying victimization. This study also investigates whether parental education moderates this association. METHODS:Using data from the Multicultural Adolescent Panel Survey, a nationally representative sample of children from multicultural families in Korea, this study employed novel asymmetric fixed-effects models that separately assess the effects of entering and exiting bullying victimization. Interaction models were conducted to consider the moderating roles of maternal and paternal college attainment. RESULTS:Conventional fixed-effects models showed that bullying victimization is significantly associated with an increase in depressive symptoms (b = 0.261). Asymmetric fixed-effects models suggest that the magnitude of the entry effect (b = 0.299) was significantly larger than that of the exit effect (b = -0.237). Furthermore, maternal college education amplified the mental health benefits of exiting from bullying victimization but did not buffer the harmful effects of entering bullying victimization. Gender-stratified analyses indicate that this protective effect of maternal college education was only significant for girls. Paternal college education, on the other hand, did not moderate either the entry or exit effects of bullying victimization. DISCUSSION:The study's findings on the asymmetric effects of bullying victimization on depressive symptoms emphasize the importance of providing follow-up care and mental health support for multicultural family youth who have experienced bullying, with particular attention to those with a history of victimization.

The aim of the study was to investigate the association between adolescent delinquency and sleep deficiency. A comprehensive set of potential mechanisms underlying this association were also examined. Using data from the National Longitudinal Study of Adolescent to Adult Health, the present study employed sibling fixed effects models to account for unobservable family-level confounders, such as genetic predisposition, parenting style, parental ability, and school and neighborhood environments. In Sobel mediation tests, the following mechanism variables were explored: substance use, school-based relationships, and parent-child relationships. An increase in delinquency (measured by the total number of types of delinquent behavior engaged) was associated with an increased risk of sleep deficiency one year later. Sibling fixed effects models with a lagged dependent variable revealed that this association is robust to adjustment for family-level heterogeneity as well as prior sleep deficiency. Substance use was the most salient pathway linking delinquency to sleep deficiency (17% for binge drinking and 26% for marijuana use), followed by student-teacher relationships (17%) and father-child relationships (16%). The results of this study suggest that policymakers and practitioners may consider developing interventions to help delinquent adolescents avoid substance use and restore disruptions of student-teacher and father-child relationships.

[Purpose] To date, there have been no studies on the response of wrist tremor to increased muscle activity during exercise. This study aimed to evaluate the wrist tremor response with increasing muscle activity during bench press exercise. [Methods] Triceps muscle activity and wrist tremor response were measured by electromyography and an accelerometer, respectively, during bench press exercise in 11 healthy men without weight-training experience. Subjects performed bench press at 30% repetition maximum (RM), and the rating of perceived exertion (RPE) and lactate concentration were measured before and after exercise. One week later, an equivalent number of bench presses at 30% RM was performed without weight load as a control trial (CT). [Results] RPEs and lactate concentrations significantly increased after resistance exercise (30% RM) from 7.4 to 14.3 and 1.7 to 4.9, respectively (P<.01), but no such difference was observed in the CT. Muscle activity linearly increased during the 30% RM exercise, and wrist tremors were shown to linearly decrease. A strong negative correlation was observed between the two variables (r=−0.88, P<.001). [Conclusion] We found that wrist tremors during resistance exercise, as measured using an accelerometer, can be used to predict muscle activity.

Hydrogen bonds (H-bonds) play an important role in determining the structures and dynamics of molecular systems. In this work, we investigated the effect of H-bonds on the vibrational population relaxation and orientational relaxation dynamics of HN3 and N3(-) in methanol (CH3OH) and N,N-dimethyl sulfoxide (DMSO) using polarization-controlled infrared pump-probe spectroscopy and quantum chemical calculations. Our detailed analysis of experimental and computational results reveals that both vibrational population relaxation and orientational relaxation dynamics of HN3 and N3(-) in CH3OH and DMSO are substantially dependent on the strength of the H-bonds between the probing solute and its surrounding solvent. Especially in the case of N3(-) in CH3OH, the vibrational population relaxation of N3(-) is found to occur by a direct intermolecular vibrational energy transfer to CH3OH due to large vibrational coupling strength. The orientational relaxation dynamics of HN3 and N3(-), which are well fit by a biexponential function, are analyzed by the wobbling-in-a-cone model and extended Debye-Stokes-Einstein equation. Depending on the intermolecular interactions, the slow overall orientational relaxation occurs under slip, stick, and superstick boundary conditions. For HN3 and N3(-) in CH3OH and DMSO, the vibrational population relaxation becomes faster but the orientational relaxation becomes slower as the H-bond strength is increased. Our current results imply that H-bonds have significant effects on the vibrational population relaxation and orientational relaxation dynamics of a small solute whose size is comparable to the size of the solvent.

Two-dimensional infrared (2DIR) spectroscopy, which has been proven to be an excellent experimental method for studying thermally-driven chemical processes, was successfully used to investigate the acid dissociation equilibrium of HN3 in methanol (CH3OH) and dimethyl sulfoxide (DMSO) for the first time. Our 2DIR experimental results indicate that the acid-base equilibrium occurs on picosecond timescales in CH3OH but that it occurs on much longer timescales in DMSO. Our results imply that the different timescales of the acid-base equilibrium originate from different proton transfer mechanisms between the acidic (HN3) and basic (N3(-)) species in CH3OH and DMSO. In CH3OH, the acid-base equilibrium is assisted by the surrounding CH3OH molecules which can directly donate H(+) to N3(-) and accept H(+) from HN3 and the proton migrates through the hydrogen-bonded chain of CH3OH. On the other hand, the acid-base equilibrium in DMSO occurs through the mutual diffusion of HN3 and N3(-) or direct proton transfer. Our 2DIR experimental results corroborate different proton transfer mechanisms in the acid-base equilibrium in protic (CH3OH) and aprotic (DMSO) solvents.

Ultrafast two-dimensional infrared (2DIR) and IR pump–probe (PP) spectroscopy was used to study the intermolecular vibrational energy transfer process from the excited state of asymmetric stretching vibration of HN3 to the overtone band of C–O stretching vibration of solvent methanol. A series of time-resolved 2DIR spectra indicate an intermolecular vibrational excitation transfer between the two modes, since the corresponding cross peaks appear at longer waiting times (>20ps). However, detailed analyses of temperature-dependent FTIR, dispersed IR PP, and 2DIR spectra showed that the vibrational relaxation of the azido stretch mode and its energy transfer to solvent methanol C–O stretch overtone mode involve not only heat dissipation directly to the solvent bath modes but also production of transient intermediate states. The present experimental work demonstrates that ultrafast nonlinear IR spectroscopy is quite useful to shed light into the complicated vibrational relaxation dynamics of H-bonded solute–solvent systems.

Ultrafast two-dimensional infrared (2DIR) spectroscopy was used to study H-bond exchange dynamics in aqueous NaPF6 solutions. Interestingly, there are two spectrally distinct hydrogen-bond (H-bond) configurations in aqueous NaPF6 solutions: water molecules that are H-bonded to PF6(-) (ODA) or other water molecules (ODW). These two spectrally distinct subsets of water in aqueous NaPF6 solutions provide an opportunity to study the individual dynamics of water in two H-bond configurations as well as interconversion dynamics between them. Most significantly, we have successfully measured H-bond exchange dynamics between two spectrally distinct H-bond configurations in real time by ultrafast 2DIR spectroscopy. In aqueous 5.0 M NaPF6 solution, water molecules switch their H-bond partners from PF6(-) to water molecule (ODA → ODW) with a time constant of 12.0 ps and from water molecule to PF6(-) (ODW → ODA) with a time constant of 21.6 ps at room temperature. H-bond exchange dynamics in aqueous NaPF6 solution were found to be relatively slower than those in aqueous NaBF4 and NaClO4 solutions which were studied previously, which was attributed to the asymmetric potential energy curve for the H-bond exchange process based on the orientational jump mechanism.

Azide ion is an excellent vibrational probe for studying ion-ion and ion-dipole interactions in solutions because its frequency is sensitively dependent on its local environments. When azide ion forms contact ion pairs with cations in dimethylsulfoxide (DMSO), free azide ion and contact ion pairs are spectrally well distinguished in FTIR spectra. Here, we investigated vibrational population relaxation, P(t), and orientational relaxation dynamics, r(t), of free azide ion and contact ion pairs (LiN3, NaN3, NH4N3, MgN3(+), and CaN3(+)) in DMSO by IR pump-probe spectroscopy. For metal azide ion pairs, the metal ion slowed down the vibrational relaxation of azide ion by acting like a thermal insulator. Biexponential behavior of r(t) was analyzed in the wobbling-in-a-cone model. The long time component of r(t) of free azide ion was found to be viscosity-dependent. The wobbling motion of azide ion within the frame of metal azide ion pairs was weakly dependent on the countercation. When the overall orientational relaxation of metal azide ion pairs was analyzed by the extended Debye-Stokes-Einstein equation, it was well described under stick or superstick boundary conditions due to a strong interaction between the metal ion and DMSO molecules. Our experimental results provide important insight in understanding the rotational dynamics of small ionic species in polar solvents when the size of the ionic species is smaller than or comparable to that of the solvent molecule.

Spectroscopic properties (i.e., peak positions and widths) of vibrational probes are sensitively dependent on their local environments in liquids. Such spectroscopic sensitivities can be utilized for studying the structures and dynamics of a variety of molecular systems. Here, we have studied the ion pairing equilibrium and dynamics of SeCN(-) ion pairs with Li(+) and Mg(2+) cations in N,N-dimethylformamide (DMF). SeCN(-) ion is an excellent vibrational probe for studying ion dynamics in electrolyte solutions, not only because the vibrational lifetime of the CN stretch is substantially long but also because the CN stretch frequency is very sensitive to its local environment. When SeCN(-) ion forms contact ion pairs (CIPs) with Li(+) (Mg(2+)) ion in DMF solutions, the CN stretch frequency is found to be significantly blue-shifted such that free SeCN(-) ion is spectrally well distinguished from Li-SeCN CIP and Mg-SeCN(+) CIP. This fact allows us to study the ion pairing equilibrium between SeCN(-) ion and metal ions as well as the dynamics of metal-SeCN(-) ion pairs. Ion pairing equilibrium between SeCN(-) ion and Li(+) (or Mg(2+)) was studied by temperature-dependent Fourier transform infrared (FTIR) spectroscopy. The formation of CIPs in DMF was found to be entropically favored. Time-resolved IR pump-probe spectroscopy was used to study the vibrational population relaxation and orientational relaxation dynamics. Vibrational lifetimes of free SeCN(-) ion, Li-SeCN CIP, and Mg-SeCN(+) CIP were determined to be 83.6, 72.3, and 55.6 ps, respectively. Orientational relaxation dynamics were found to get slower in the order free SeCN(-) ion, Li-SeCN CIP, and Mg-SeCN(+) CIP. The orientational anisotropy decays of the CIPs, which were well fit by a biexponential function, were explained by two orientational relaxation processes, that is, a restricted (tethered) orientational relaxation of SeCN(-) within the CIPs followed by the overall orientational diffusion of the whole CIPs. The orientational relaxation time constants of Li-SeCN CIP and Mg-SeCN(+) CIP in DMF were twice different but the orientational diffusion radii calculated by the Debye-Stokes-Einstein equation were found to be almost identical within experimental error. The biexponential decay of the orientational anisotropy was analyzed by the wobbling-in-a-cone model. As a vibrational probe, SeCN(-) ion and SeCN group can be potentially used for measuring the molecular dynamics on a relatively long time scale because of their long lifetimes.

Ultrafast two-dimensional infrared (2DIR) spectroscopy has been proven to be an exceptionally useful method to study chemical exchange processes between different vibrational chromophores under thermal equilibria. Here, we present experimental results on the thermal equilibrium ion pairing dynamics of Li(+) and SCN(-) ions in N,N-dimethylformamide. Li(+) and SCN(-) ions can form a contact ion pair (CIP). Varying the relative concentration of Li(+) in solution, we could control the equilibrium CIP and free SCN(-) concentrations. Since the CN stretch frequency of Li-SCN CIP is blue-shifted by about 16 cm(-1) from that of free SCN(-) ion, the CN stretch IR spectrum is a doublet. The temperature-dependent IR absorption spectra reveal that the CIP formation is an endothermic (0.57 kJ∕mol) process and the CIP state has larger entropy by 3.12 J∕(K mol) than the free ion states. Since the two ionic configurations are spectrally distinguishable, this salt solution is ideally suited for nonlinear IR spectroscopic investigations to study ion pair association and dissociation dynamics. Using polarization-controlled IR pump-probe methods, we first measured the lifetimes and orientational relaxation times of these two forms of ionic configurations. The vibrational population relaxation times of both the free ion and CIP are about 32 ps. However, the orientational relaxation time of the CIP, which is ∼47 ps, is significantly longer than that of the free SCN(-), which is ∼7.7 ps. This clearly indicates that the effective moment of inertia of the CIP is much larger than that of the free SCN(-). Then, using chemical exchange 2DIR spectroscopy and analyzing the diagonal peak and cross-peak amplitude changes with increasing the waiting time, we determined the contact ion pair association and dissociation time constants that are found to be 165 and 190 ps, respectively. The results presented and discussed in this paper are believed to be important, not only because the ion-pairing dynamics is one of the most fundamental physical chemistry problems but also because such molecular ion-ion interactions are of critical importance in understanding Hofmeister effects on protein stability.