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Rates of youth suicidal thoughts and behaviors (STBs) are rising, and younger age at onset increases vulnerability to negative outcomes. However, few studies have investigated STBs in early adolescence (ages 10-13), and accurate prediction of youth STBs remains poor. Network analyses that can examine pairwise associations between many theoretically relevant variables may identify complex pathways of risk for early adolescent STBs. The present study applied longitudinal network analysis to examine interrelations between STBs and several previously identified risk and protective factors. Data came from 9,854 youth in the Adolescent Brain Cognitive Development Study cohort ( M age = 9.90 ± .62 years, 63% white, 53% female at baseline). Youth and their caregivers completed an annual measurement battery between ages 9-10 through 11-12 years. Panel Graphical Vector Autoregressive models evaluated associations between STBs and several mental health symptoms, socioenvironmental factors, life stressors, and substance use. In the contemporaneous and between-subjects networks, direct associations were observed between STBs and internalizing symptoms, substance use, family conflict, lower parental monitoring, and lower school protective factors. Potential indirect pathways of risk for STBs were also observed. Age-specific interventions may benefit from prioritizing internalizing symptoms and early substance use, as well as promoting positive school and family support.

The period after psychiatric hospitalization is an extraordinarily high-risk period for suicidal thoughts and behaviours (STBs). Affective-cognitive constructs (ACCs) are salient risk factors for STBs, and intensive longitudinal metrics of these constructs may improve personalized risk detection and intervention. However, limited research has examined how within-person daily levels and between-person dynamic metrics of ACCs relate to STBs after hospital discharge. Adult psychiatric inpatients (N = 95) completed a 65-day ecological momentary assessment protocol after discharge as part of a 6-month follow-up period. Using dynamic structural equation models, we examined both within-person daily levels and between-person dynamic metrics (intensity, variability and inertia) of positive and negative affect, rumination, distress intolerance and emotion dysregulation as risk factors for STBs. Within-person lower daily levels of positive affect and higher daily levels of negative affect, rumination, distress intolerance and emotion dysregulation were risk factors for next-day suicidal ideation (SI). Same-day within-person higher rumination and negative affect were also risk factors for same-day SI. At the between-person level, higher overall positive affect was protective against active SI and suicidal behaviour over the 6-month follow-up, while greater variability of rumination and distress intolerance increased risk for active SI, suicidal behaviour and suicide attempt. The present study provides the most comprehensive examination to date of intensive longitudinal metrics of ACCs as risk factors for STBs. Results support the continued use of intensive longitudinal methods to improve STB risk detection. Interventions focusing on rumination and distress intolerance may specifically help to prevent suicidal crises during critical transitions in care., (© 2024 John Wiley & Sons Ltd.)

Heavy episodic drinking (HED) is a major public health concern, and youth who engage in HED are at increased risk for alcohol-related problems that continue into adulthood. Importantly, there is heterogeneity in the onset and course of adolescent HED, as youth exhibit different trajectories of initiation and progression into heavy drinking. Much of what is known about the etiology of adolescent HED and alcohol-related problems that persist into adulthood comes from studies of predominantly White, middle-class youth. Because alcohol use and related problems vary by race/ethnicity and socioeconomic status, it is unclear whether previous findings are relevant for understanding developmental antecedents and distal consequences of adolescent HED for minoritized individuals. In the current study, we utilize a developmental psychopathology perspective to fill this gap in the literature. Using a racially and economically diverse cohort followed from adolescence well into adulthood, we apply group-based trajectory modeling (GBTM) to identify patterns of involvement in HED from age 14 to 17 years. We then investigate developmental antecedents of GBTM class membership, and alcohol-related distal outcomes in adulthood (∼ age 31 years) associated with GBTM class membership. Results highlight the importance of adolescent alcohol use in predicting future alcohol use in adulthood.

Objective: Health-risk behaviors have an unclear etiology and college students have elevated risk for engagement. Emotion dysregulation and several personality dimensions have been implicated in health-risk behaviors, but these constructs have rarely been studied together. Further, it is unknown if different types of health-risk behaviors have distinct etiologies., Participants: 2077 college students completed a cross-sectional survey., Methods: Latent profile analysis discerned classes of participants from emotion dysregulation and personality dimensions. Differential engagement in self-injury, suicidality, disordered eating, substance misuse, and unprotected sex was evaluated across classes., Results: Three classes were identified, which were primarily distinguished by emotion dysregulation, urgency, and neuroticism. Health-risk behaviors generally increased across classes with increasing emotion-related constructs. Self-injury and suicidality demonstrated different patterns than other health-risk behaviors., Conclusions: Results elucidate heterogeneity in health-risk behavior engagement. Focusing on emotional difficulties may be more important for reducing self-injury and suicidality than disordered eating, substance misuse, and risky sex.

Objective: Extreme sport participation and injury rates have increased in recent decades. This study aimed to investigate sub-dimensions of impulsivity and sensation seeking that contribute to participation and injury risk in extreme sports., Participants: Data included cross-sectional survey responses from 7,109 college students ( Mage  = 19.68, SD = 2.31)., Methods: This study utilized path analysis to investigate sub-dimensions of sensation seeking and impulsivity as predictors of extreme sport participation and injury across 3 models., Results: Results of the final model identify risk seeking and lack of perseverance as the two strongest predictors of extreme sports injury, risk seeking, experience seeking, and lack of premeditation as the strongest positive predictors of extreme sports participation, and lack of perseverance as the strongest negative predictor of extreme sports participation., Conclusions: These results will contribute to targeted prevention and intervention efforts for extreme sports injury among young adults based on identified individual personality factors.

Increasing understanding of the risk and protective factors for adolescent nonmedical use of prescription drugs (NMUPD) could inform prevention efforts. Several correlates have been identified, including parental factors, perceptions about use and accessibility, social norms, and age. However, these constructs have rarely been simultaneously examined using paired data from parents and adolescents. We aimed to examine the relative influence of these correlates among dyads ( N =349) of mothers and adolescent daughters. Using multiple logistic regression, daughters' past NMUPD and inclination for future NMUPD were regressed onto descriptive norms for friend use, perceived drug accessibility and risk of harm from use, daughter age, mothers' disapproval about use, mothers' past NMUPD and inclination for future NMUPD, and the mother-daughter relationship quality. Akaike weights and lasso regressions were also estimated to evaluate the relative importance of each correlate. Higher descriptive norms for friend use, older age, and mothers' inclination for NMUPD were risk factors for daughters' NMUPD, while a closer mother-daughter relationship and mothers' disapproving attitudes towards NMUPD were protective factors. The three analysis approaches were corroborative. Results suggest friend descriptive norms, mother-daughter relationship quality, and mothers' attitudes about NMUPD are important prevention targets.

Previous research indicates that sensation seeking, emotion dysregulation, and impulsivity are predictive of non-suicidal self-injury (NSSI). A body of research supports that meaning in life predicts improved mental health and well-being, including fewer suicidal thoughts and attempts, yet no research has examined the moderating effects of meaning in life on the relations between personality and temperament and NSSI. Given the growing incidence rates of NSSI among adolescents and the potential lifelong consequences of NSSI, it is imperative to better understand the factors that reduce the rates at which adolescents in a clinical sample engage in NSSI. The present study investigates if the protective factors of meaning in life moderate the relation between personality and temperament variables and NSSI among 126 adolescents (71% female, Mage = 16.1, SD = 1.1, range 13-18, 80% White) residing in an inpatient psychiatric hospital who endorsed NSSI in the last 12 months. Results from hurdle modeling indicate that two subtypes of meaning in life, presence of meaning in life and search for meaning of life, may serve as robust protective factors against engagement in NSSI among a clinical sample of adolescents. Additionally, results suggest that search for meaning, but not presence of meaning in life, variables moderate the relations between personality and temperament and NSSI. Results provide evidence that meaning in life is an understudied variable of importance in understanding how to prevent or treat NSSI. It also underscores the need to develop, refine, and test meaning-making interventions., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

College students have an elevated risk for self-injurious thoughts and behaviours (SITBs), and there are robust differences in prevalence rates for SITBs across gender identities. Although numerous constructs have been implicated as risk factors, researchers have not significantly improved at predicting SITBs, possibly owing to constraints of confirmatory analyses. Classification trees are exploratory, person-centred analyses that enable joint examination of numerous correlates and their interactions. Thus, classification trees may discern previously unstudied risk factors and identify distinct subpopulations with elevated risk for SITBs. We tested classification trees that evaluated 298 potential correlates of nonsuicidal self-injury and suicidal ideation across self-identified women and men. Data came from 5,131 college students who completed the National College Health Assessment, which assesses a wide range of health-related constructs. Models produced parsimonious decision trees that accounted for a substantial amount of outcome variability (38.3-51.5%). Psychopathology, poorer psychological well-being, and other SITBs emerged as important correlates for all participants. Trauma, disordered eating, and heavy alcohol use were salient among women, whereas alcohol use norms were important correlates among men. Importantly, models identified several constructs that may be amenable to intervention. Results support the use of exploratory analyses to explicate heterogeneity among individuals who engage in SITBs and suggest that gender identity is an important moderator for certain risk factors., (© 2020 John Wiley & Sons, Ltd.)

Background: Young adults have elevated risk for negative marijuana use-related outcomes, and there is heterogeneity among users. Identifying risk factors for marijuana user status will improve understanding of different populations of users, which may inform prediction of individuals most likely to experience negative outcomes. Objectives: To identify predictors of marijuana use initiation in young adults. We simultaneously examined a broad range of potential predictors and all their possible interactions, including constructs that have not been previously studied in substance use initiation research. Methods: Data were repeated cross-sectional survey responses from college students in Colorado ( N  = 4052, 77% White, 61% female, mean age = 22.77). Measures came from the National College Health Assessment, which assesses numerous health and behavioral constructs. We used recursive partitioning and random forest models to identify predictors of ever having used marijuana out of 206 variables. Results: Classification trees identified engagement in increased alcohol use and sexual behavior as salient correlates of marijuana use initiation. Parsimonious recursive partitioning trees explained a substantial amount of variability in marijuana user status (39% in the full model and 24% when alcohol variables were excluded). Random forest models predicted user status with 74.11% and 66.91% accuracy in the full model and when alcohol variables were excluded, respectively. Conclusions: Results support the use of exploratory analyses to explain heterogeneity among marijuana users and non-users. Since engagement in other health-risk behaviors were salient predictors of use initiation, prevention efforts to reduce harm from marijuana use may benefit from targeting risk factors for health-risk behaviors in general.

Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.

A passive equilibrium probe, sonic-assisted free ion recorder (SAFIR), was recently developed to monitor free Cu ion activity ({Cu(2+)}) in aquatic environments. The SAFIR is user-friendly and can be deployed on-site to record the ambient {Cu(2+)} in an accurate and fast manner. It consists of a chemically modified polystyrene disk (Primaria disk) containing metal ion-binding functional groups, coupled with a sonic horn in a flow-through cell. The calibration of the disk was successfully conducted in metal-ion buffered seawater solutions (pH 8.2, salinity = 32) with {Cu(2+)} ranging from 10(-9.0) to 10(-15.0) mol/L. The Cu adsorbed on the surface of the Primaria disk (Cu(ads)) correlated linearly with the ambient {Cu(2+)} through a Frendlich equilibrium adsorption model. The adsorption process was kinetically enhanced by the introduction of ultrasound, allowing equilibrium between the SAFIR and the ambient {Cu(2+)} in 10 min. The SAFIR was deployed in several coastal regions, and the {Cu(2+)} recorded by SAFIR were in good agreement with the results obtained from corresponding electrochemical analysis.

Triclosan is an antimicrobial agent added to a wide array of consumer goods and personal care products. Through its use, it is introduced into municipal sewer systems where it is only partially removed during wastewater treatment. In this study, triclosan was measured in dated sediment cores from four urbanized estuaries in order to reconstruct temporal and spatial trends of accumulation. Measurable concentrations of triclosan first appeared in each of the sediment cores near 1964, which corresponds with the US patent issuance date of triclosan. The presence of triclosan at each of the study sites at or near the patent date indicates that long-term preservation is occurring in estuarine sediments. Temporal trends of triclosan at each location are unique, reflecting between site variability. Concentrations at one site climbed to as high as 400ngg(-1), due in part, to local commercial production of triclosan. At two locations, levels of triclosan rise towards the surface of each core, suggesting increasing usage in recent years. One location adjacent to a major combined sewer overflow had high sediment concentrations of triclosan, confirming their potential as a source of triclosan to estuaries., (Published by Elsevier Ltd.)

Few studies have directly addressed the question of how metals (both essential and nonessential) are transported in the circulatory system of bivalve mollusks. One potential metal-transport protein, histidine-rich glycoprotein (HRG), has previously been isolated and characterized from the blood plasma of the marine mussel Mytilus edulis L. The present study was undertaken to investigate the extent to which mussel HRG can bind a variety of essential and nonessential metals in vitro, using immobilized metal-ion affinity chromatography (IMAC) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The equilibrium metal speciation model MINTEQA2 was used to compute the amount of metal that bound to the IMAC packing material during the charging and initial wash steps. Results demonstrated that HRG can bind all seven of the metals tested (Ca, Cd, Hg, Mg, Ni, Pd, and Zn) and that HRG is the only metal-binding protein in IMAC eluents. Because HRG-metal binding strengths (log K(a)) likely correspond with histidine-metal binding strengths, and because HRG is the predominant mussel plasma protein, the majority of each of the seven metals probably would be present in mussel blood as protein-bound metal rather than as free metal ion. The finding that a single mussel plasma protein may be responsible for binding all these metals raises important questions about how these different metals are subsequently transferred from HRG to different tissues of the mussel, where they may exhibit tissue-specific patterns of utilization, sequestration, elimination, and toxicity.

To determine whether Culiseta melanura (Coquillett) mosquitoes tend to take multiple blood meals when birds of certain species serve as hosts, we compared the frequencies with which such mosquitoes fed upon caged starlings and robins and determined whether similar volumes of blood were imbibed from each. The blood of robins (Turdus migratorius) and European starlings (Sturnus vulgaris) was marked contrastingly by injecting birds with rubidium or cesium salts. Caged birds were placed together in a natural wetland setting overnight. Mosquitoes captured nearby on the following morning were analyzed for each of the elemental markers. Where marked robins and starlings were equally abundant, 43% of freshly engorged Cs. melanura fed on more than or equal to two hosts. More Cs. melanura fed on robins than on starlings. Individual mosquitoes tended to contain far more robin- than starling-associated marker, indicating that mosquitoes "feasted" on robins but only "nibbled" on starlings. Mosquitoes marked with both elements apparently fed meagerly on the starlings then abundantly on the robins. Our estimates of bloodmeal volume indicate that 85% of mosquitoes that fed on marked starlings obtained < 0.5 microliter of blood from them. We suggest that defensive behavior by starlings interrupts mosquito blood-feeding and that, in a communal roost of starlings, each mosquito will tend to feed on more than one bird, thereby promoting rapid transmission of such ornithonotic arboviruses as eastern equine encephalomyelitis virus and West Nile virus.

Ingested matter can have a significant effect on whole body metal concentration measurements in Mytilus edulis. Depuration of mussels in clean seawater for 36 h prior to dissection eliminates most of these contaminating gut contents. Depuration followed by metal analyses is the most direct method of determining mussel tissue metal bioburdens. After being transplanted into a plume of primary treated sewage effluent in Salem Harbor, Massachusetts for 32 days, Al, Cr, and Fe concentrations in depurated mussels were significantly lower than those determined for either non-depurated mussels or for depurated mussels to which fecal concentrations of Al, Cr, and Fe were added back in. Although mathematical methods developed by both Ouellette (1978) and Boehm et al. (1988) could be applied to non-depurated mussels in order to correct for errors associated with gut metal contamination, these indirect methods were not as reliable as depuration prior to analysis.