Using random forest to identify correlates of depression symptoms among adolescents.

PURPOSE: Adolescent depression is a significant public health concern, and studying its multifaceted factors using traditional methods possess challenges. This study employs random forest (RF) algorithms to determine factors predicting adolescent depression scores. METHODS: This study utilized self-reported survey data from 56,008 Canadian students (grades 7-12) attending 182 schools during the 2021/22 academic year. RF algorithms were applied to identify the correlates of (i) depression scores (CESD-R-10) and (ii) presence of clinically relevant depression (CESD-R-10 ≥ 10). RESULTS: RF achieved a 71% explained variance, accurately predicting depression scores within a 3.40 unit margin. The top 10 correlates identified by RF included other measures of mental health (anxiety symptoms, flourishing, emotional dysregulation), home life (excessive parental expectations, happy home life, ability to talk to family), school connectedness, sleep duration, and gender. In predicting clinically relevant depression, the algorithm showed 84% accuracy, 0.89 sensitivity, and 0.79 AUROC, aligning closely with the correlates identified for depression score. CONCLUSION: This study highlights RF's utility in identifying important correlates of adolescent depressive symptoms. RF's natural hierarchy offers an advantage over traditional methods. The findings underscore the importance and additional potential of sleep health promotion and school belonging initiatives in preventing adolescent depression.

Factors associated with prospective changes in weight control intentions among adolescents.

INTRODUCTION: The present study examined predictors of negative changes in weight control intentions from before to during the COVID-19 pandemic among adolescents. METHODS: Participants were Canadian secondary school students enrolled in the COMPASS study and had completed self-report surveys before (T1; 2018/2019 and/or 2019/2020 school year) and during (T2; 2020/2021 and/or 2021/2022) the COVID-19 pandemic (N = 11,869, Mage ± SD = 13.79 years old ± 1.15, 52.89% girls, 45.30% boys, 1.81% gender diverse). Demographic, interpersonal, behavioral, and psychological predictors of weight control intention change from T1 (stay the same weight, not doing anything about weight) to T2 (lose weight, gain weight) were tested using multilevel logistic regressions. RESULTS: Over one-third (37.0%) of adolescents who reported wanting to stay the same weight at T1 changed their intention to lose or gain weight at T2, as did 28.5% of adolescents who reported not wanting to do anything about their weight at T1. Changing weight control intention from "not doing anything about weight" at T1 to weight gain/loss at T2 was associated with resistance training, emotion dysregulation, bullying, social media use, and gender. Changing weight control intention from "stay the same weight" at T1 to weight gain/loss at T2 was associated with gender, perceived financial comfort, social media use, and flourishing. CONCLUSIONS: Results highlight the prevalence of maladaptive weight control intention changes among adolescents, and elucidate related behavioral, interpersonal, demographic, and psychological factors. Findings can inform targeted intervention and prevention strategies to disrupt maladaptive changes in weight control intentions among high-risk subgroups.

The intersection of internalizing symptoms and alcohol use during the COVID-19 pandemic: A prospective cohort study.

Given the well-established relationship between alcohol and internalizing symptoms, potential increases in depression and anxiety during the COVID-19 pandemic may lead to increases in alcohol consumption and binge drinking. This study examines this association from before to during two phases of the pandemic in a cohort of Canadian youth. We used linked data from a sub-sample of 1901 secondary school students who participated in three consecutive school years of the Cannabis use, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study between 2018/19 and 2020/21. Separate multilevel logistic regression models examined the association between depression and anxiety symptoms with odds of escalation and reduction (vs. maintenance) and initiation (vs. abstinence) of alcohol consumption. Results show that depression and anxiety symptoms significantly increased over the three years, and these changes were moderated by changes in alcohol consumption and binge drinking. Students with increased depression symptoms were less likely to reduce their alcohol consumption in the early pandemic (Adjust odds ratio [AOR] 0.94, 95% CI:0.90-0.98), more likely to initiate alcohol consumption in the ongoing pandemic period (AOR 1.03, 95% CI: 1.01-1.05), and more likely to initiate binge drinking in both periods. The depression-alcohol use association was stronger among females than males. This study demonstrates a modest association between internalizing symptoms and alcohol use, particularly for depression symptoms and in females. The identified depression-alcohol use association suggests that preventing or treating depression might be beneficial for adolescent alcohol use and vice versa.

Patterns of enteric infections in a population-wide cohort study of sequelae, British Columbia, Canada.

We assessed patterns of enteric infections caused by 14 pathogens, in a longitudinal cohort study of sequelae in British Columbia (BC) Canada, 2005-2014. Our population cohort of 5.8 million individuals was followed for an average of 7.5 years/person; during this time, 40 523 individuals experienced 42 308 incident laboratory-confirmed, provincially reported enteric infections (96.4 incident infections per 100 000 person-years). Most individuals (38 882/40 523; 96%) had only one, but 4% had multiple concurrent infections or more than one infection across the study. Among individuals with more than one infection, the pathogens and combinations occurring most frequently per individual matched the pathogens occurring most frequently in the BC population. An additional 298 557 new fee-for-service physician visits and hospitalisations for enteric infections, that did not coincide with a reported enteric infection, also occurred, and some may be potentially unreported enteric infections. Our findings demonstrate that sequelae risk analyses should explore the possible impacts of multiple infections, and that estimating risk for individuals who may have had a potentially unreported enteric infection is warranted.

Cannabis Use, Screen Time, and Internalizing Symptoms among Canadian Youth: Testing Mediation Pathways.

Background: Existing research suggests positive correlations between screen time sedentary behaviors (STSB) and substance use, including cannabis use, among youth. However, little research has examined what factors mediate these relationships.Methods: This study examined mediating pathways among STSB, internalizing symptoms (IS), and cannabis use in a linked longitudinal sample of 28 269 Canadian youth who participated in the COMPASS study over a two-year period (2017/18 to 2018/19). Structural equation modeling examined two main hypotheses cross-sectionally and over time: 1) if IS mediated associations between STSB and cannabis use frequency, and 2) if STSB mediated associations between IS and cannabis use frequency. Results: Results demonstrated significant partial mediation effects for both hypotheses. For example, indirect effects indicated that IS mediated the association between STSB and cannabis use both cross sectionally (95% CI: 0.021, 0.029) and longitudinally (95% CI: 0.006, 0.010). STSB also mediated associations between IS and cannabis use cross sectionally (95% CI: 0.015, 0.023) and longitudinally (95% CI: 0.010, 0.014). This study demonstrated that the associations between STSB, internalizing symptoms and cannabis use are complex, involving mediation in both directions.Discussion: These findings can be used to inform public health initiatives that aim to take a comprehensive approach to addressing negative health behaviors and outcomes, as it is clear that the multi-directional relationships between STSB and mental health may in-turn impact other health behaviors. Future research should continue to examine mediating factors between STSB and substance use among youth, including exploration of associations with other substances.Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1922455 .

The role of school characteristics in pre-legalization cannabis use change among Canadian youth: implications for policy and harm reduction.

Reducing youth cannabis use in Canada is a public health priority with schools of interest as a potential modifier of behavior and as a venue for prevention programming. This work aimed to provide a basis for future policy and programming by evaluating pre-legalization cannabis use change patterns in schools and the impact of school characteristics on these patterns. Average rates of cannabis use behavior change (initiation, escalation, reduction, cessation) were collected from 88 high schools located in Ontario and Alberta, Canada participating in the COMPASS prospective cohort study. There was little variability in cannabis use behaviors between schools with intra-class correlation coefficients lowest for cessation (0.02) and escalation (0.02) followed by initiation (0.03) and reduction (0.05). Modest differences were found based on school province, urbanicity and student-peer use. Cannabis ease of access rates had no significant effect. Fewer than half the schools reported offering school drug use prevention programs; these were not significantly associated with student cannabis use behaviors. In conclusion, current school-based cannabis prevention efforts do not appear sufficiently effective. Comprehensive implementation of universal prevention programs may reduce cannabis harms. Some factors (urbanicity, peer use rates) may indicate which schools to prioritize.

Acoustic localization of vehicular sources using distributed sensors.

This paper considers the problem of locating ground vehicles using their acoustic signatures recorded by unattended passive acoustic sensors. Acoustic signatures of the ground sources captured by different sensors within a cluster are used to generate direction of arrival (DoA) of the propagating wavefronts. Using the estimated DoAs of disparate distributed sensor node clusters, this paper introduced and compared several different existing target localization methods that provide the location and velocity estimates of a moving source. A robust source localization method is then proposed to account for large DoA errors and outliers which often occur in realistic settings. This method does not use any prior knowledge of the dynamical model of the moving source. The effectiveness and complexity of these methods are compared using synthesized and real acoustic signature data sets.

Time-Frequency Analysis of Cardiovascular and Cardiorespiratory Interactions During Orthostatic Stress by Extended Partial Directed Coherence.

In this study, the linear method of extended partial directed coherence (ePDC) was applied to establish the temporal dynamic behavior of cardiovascular and cardiorespiratory interactions during orthostatic stress at a 70° head-up tilt (HUT) test on young age-matched healthy subjects and patients with orthostatic intolerance (OI), both male and female. Twenty 5-min windows were used to analyze the minute-wise progression of interactions from 5 min in a supine position (baseline, BL) until 18 min of the orthostatic phase (OP) without including pre-syncopal phases. Gender differences in controls were present in cardiorespiratory interactions during OP without compromised autonomic regulation. However in patients, analysis by ePDC revealed considerable dynamic alterations within cardiovascular and cardiorespiratory interactions over the temporal course during the HUT test. Considering the young female patients with OI, the information flow from heart rate to systolic blood pressure (mechanical modulation) was already increased before the tilt-up, the information flow from systolic blood pressure to heart rate (neural baroreflex) increased during OP, while the information flow from respiration to heart rate (respiratory sinus arrhythmia) decreased during the complete HUT test. Findings revealed impaired cardiovascular interactions in patients with orthostatic intolerance and confirmed the usefulness of ePDC for causality analysis.

Retinoid BMS411 (4-{[(5,5-dimethyl-8-phenyl-5,6-dihydronaphthalen-2-yl) carbonyl] amino} benzoic acid), a potential inhibitor of NS5A protein of hepatitis C virus, a candidate for combined therapy of hepatitis C infection.

Hepatitis C infection is a serious health issue worldwide caused by hepatitis C virus (HCV). There is an urgent need of search for new direct acting antiviral drugs due to the rapid development of drug resistance. The HCV NS5A protein is involved in creating resistance against antiviral therapy and there are also many reports that vitamin A deficiency is associated with non-responsiveness to antiviral treatment in HCV infected patients. So the present in silico study was aimed to find the relation between vitamin A deficiency and the NS5A protein's function in antiviral resistance. Structure of NS5A protein was predicted by using I-Tasser (Interactive Tasser). Previous data on conservative domains and dimer formation were confirmed by using a series of current computational methods. The structure was employed for molecular docking analysis to investigate the interaction of ligand BMS411 (4-[(5,5-dimethyl-8-phenyl-6H-naphthalene-2-carbonyl)amino]benzoic acid), a vitamin A related compound with NS5A protein. Docking analysis showed that retinoid BMS411 can bind to HCV NS5A protein and may act as inhibitor of this protein. The functionally interacting amino acid residues surrounding the ligand molecule were identified and were shown to be involved in the formation of binding pocket. The present study suggests that retinoids may play an important role in the improvement of the outcomes of antiviral therapy against HCV through interaction with NS5A and inhibition of this protein. It is of great importance to check and verify if other retinoids could act as NS5A inhibitors.

Orientation of Anopheles gambiae (Diptera: Culicidae) to Plant-Host Volatiles in a Novel Diffusion-Cage Olfactometer.

A novel diffusion-cage olfactometer tested the responses of Anopheles gambiae Giles to plant volatiles. Green-leaf volatiles are often released from cut or injured plant tissue and may alter the headspace of plants used in olfactometer assays. The diffusion-cage olfactometer is designed for use with whole, intact plants, hence giving a more realistic behavioral assay. Its simple plastic construction, ease of assembly, and accommodation to whole plants makes it a useful tool for measuring mosquito orientation to plant volatiles within large enclosures. We compared its performance to that of the more commonly used T-tube wind-tunnel olfactometer, by testing the orientation of mosquitoes to volatiles of a few prevalent plants of eastern Africa reportedly utilized by An. gambiae for sugar: Parthenium hysterophorus (Asteraceae), Ricinus communis (Euphorbiaceae), Lantana camara (Verbenaceae), and Senna occidentalis (Fabaceae). Results indicate that the diffusion-cage olfactometer is an effective alternative to conventional wind-tunnel olfactometers, to test mosquito orientation to plant volatiles under seminatural conditions.

Evaluation of Bacillus thuringiensis israelensis as a Control Agent for Adult Anopheles gambiae.

Unlike the application of Bacillus thuringiensis israelensis (Bti) for the control of larval mosquitoes, studies of its effects on adults, for its possible use in attractive toxic sugar baits, have resulted in conflicting results. Five species have shown a decrease in adult survival due to Bti ingestion, whereas adults of Anopheles arabiensis have not. We sought to determine if ingestion of Bti by adults of Anopheles gambiae, a sibling species of An. arabiensis, increases their mortality. Laboratory-reared adults were provided continuously from emergence with water only, a sucrose solution, or a Bti suspension in sucrose solution. After 3 days, the Bti suspension was replaced with untainted sucrose solution. The mosquitoes with only water were all dead by day 3. The survivorships of those in the sucrose and sucrose-Bti treatments were insignificantly different, both with an LT50 (Lethal Time, time until 50% of individuals died) of 25 days. The results support the conclusion that adult survivorship of An. gambiae-complex members is unaffected by the ingestion of Bti in sugar meals.

Optimizing adsorption of Cr(VI) from aqueous solutions by NiO nanoparticles using Taguchi and response surface methods.

In the present study, nickel oxide nanoparticles synthesized by the sol-gel method were used as an effective adsorbent for the removal of Cr(VI) from aqueous solutions. To do so, the effect of four parameters including the concentration of Cr(VI), the dosage of NiO, contact time, and pH on the removal of Cr(VI) by NiO nanoparticles were studied. In order to examine and describe the optimum conditions for each of the mentioned parameters, Taguchi and response surface methods were used. The results of the experiment using Taguchi and response surface methods indicated the greater effect of the NiO adsorbent parameter in comparison to the other parameters in the adsorption of Cr(VI) by NiO nanoparticles, and showed that the increase in contact time and pH does not affect the removal percentage of Cr(VI) significantly.

A statistical-based approach for acoustic tomography of the atmosphere.

Acoustic travel-time tomography of the atmosphere is a nonlinear inverse problem which attempts to reconstruct temperature and wind velocity fields in the atmospheric surface layer using the dependence of sound speed on temperature and wind velocity fields along the propagation path. This paper presents a statistical-based acoustic travel-time tomography algorithm based on dual state-parameter unscented Kalman filter (UKF) which is capable of reconstructing and tracking, in time, temperature, and wind velocity fields (state variables) as well as the dynamic model parameters within a specified investigation area. An adaptive 3-D spatial-temporal autoregressive model is used to capture the state evolution in the UKF. The observations used in the dual state-parameter UKF process consist of the acoustic time of arrivals measured for every pair of transmitter/receiver nodes deployed in the investigation area. The proposed method is then applied to the data set collected at the Meteorological Observatory Lindenberg, Germany, as part of the STINHO experiment, and the reconstruction results are presented.

An Examination of Bidirectional Associations Between Alcohol Use and Internalizing Symptoms Among Adolescents During the COVID-19 Pandemic.

PURPOSE: This study explores the bidirectional association between internalizing symptoms and alcohol use over three years of the COVID-19 pandemic to examine whether alcohol consumption is associated with higher internalizing symptoms in the next year and vice versa. METHODS: We used linked data from a sample of 2,136 secondary school students who participated in three consecutive waves (2019-2020 [T1], 2020-2021 [T2], and 2021-2022 [T3]) of the Cannabis use, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour study during the pandemic. A random-intercept cross-lagged panel model was used to characterize reciprocal linear relations between internalizing symptoms and alcohol use. RESULTS: The findings suggest that students who reported higher levels of alcohol use at T1 experienced increased levels of depression and anxiety in the subsequent year (T2). However, this association was not observed from T2 to T3. Throughout the three-year period, depression and anxiety were not associated with later alcohol use. In males, alcohol use at T1 was a predictor of higher internalizing symptoms at T2 but not from T2 to T3. DISCUSSION: These results suggest time-sensitive impacts and notable gender differences in the relationship between internalizing symptoms and alcohol use over the pandemic. Given the complexity of impacts, ongoing evaluation of the impact of the pandemic on youth health behaviours is necessary to elucidate these unfolding relationships, especially as the pandemic continues to affect various psychosocial risk factors.

Inequitable Changes in School Connectedness During the Ongoing COVID-19 Pandemic in a Cohort of Canadian Adolescents.

BACKGROUND: We examined whether subgroups of adolescents experienced disparate changes in school connectedness-a robust predictor of multiple health outcomes-from before the COVID-19 pandemic to the first full school year following pandemic onset. METHODS: We used 2 waves of prospective survey data from 7178 students attending 41 Canadian secondary schools that participated during the 2019-2020 (T1; pre-COVID-19 onset) and 2020-2021 (T2; ongoing pandemic) school years. Fixed effects analyses tested differences in school connectedness changes by gender, race, bullying victimization, socioeconomic position, and school learning mode. RESULTS: Relatively greater declines in school connectedness were reported by students that identified as females, were bullied, perceived their family to be less financially comfortable than their classmates, and attended schools in lower income areas. Marginally greater school connectedness declines resulted among students attending schools that were fully online at T2 than those at schools using a blended model. CONCLUSION: Results point to disparate school connectedness declines during the pandemic, which may exacerbate pre-existing health inequities by gender and socioeconomic position, and among bullied youth. IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY: Effective strategies to improve school climates for equity denied groups are critical for pandemic recovery and preparedness for future related events.

Adolescents' Depression and Anxiety Symptoms During the COVID-19 Pandemic: Longitudinal Evidence From COMPASS.

PURPOSE: There is concern over the potentially detrimental impact of the COVID-19 pandemic on adolescents' mental health. We examined changes in depression and anxiety symptoms from before (2018-19) to the early (2019-20) and ongoing pandemic (2020-21) responses among Canadian adolescents in the context of a natural experiment. METHODS: We used linked survey data from 5,368 Canadian secondary school students who participated in three consecutive waves of the cannabis use, obesity, mental health, physical activity, alcohol use, smoking, and sedentary behaviour study during the 2018-19, 2019-20, and 2020-21 school year. Separate fixed effects models examined whether changes in depression (Center for Epidemiologic Studies Depression Scale Revised-10) and anxiety (General Anxiety Disorder-7) symptoms differed between two cohorts. The cohorts differed in the timing of their second data collection wave; one cohort participated before the pandemic and the other cohort participated in the early pandemic (spring 2020). RESULTS: Depression and anxiety symptoms increased during the early and ongoing pandemic periods in the overall sample and both cohorts. The two cohorts experienced similar elevations in their symptoms. Females and younger respondents presented greater elevations over time. The proportion of adolescents with significant depressive (29.4%) and moderate-to-severe anxiety (17.6%) symptoms at baseline increased by 1.5 times, reaching 44.8% and 29.8% in the ongoing pandemic period, respectively. DISCUSSION: Findings suggest that internalizing symptoms have consistently increased since before the onset of COVID-19, particularly in the ongoing pandemic period; however, we found no evidence of the increase being due to the pandemic in the early COVID-19 period when comparing the two cohorts. Ongoing evaluation of adolescents' mental health is necessary to capture potentially dynamic impacts over time.

The association between single and dual use of cannabis and alcohol and driving under the influence and riding with an impaired driver in a large sample of Canadian adolescents.

OBJECTIVE: Dual use of cannabis and alcohol has increased in adolescents, but limited research has examined how it relates to impaired driving or riding with an impaired driver (IDR) compared to single substance use. This study aimed to examine the odds of alcohol- and/or cannabis-IDR among adolescents based on their use of alcohol and/or cannabis, and whether associations differed by gender and age. METHODS: Cross-sectional survey data were used from a sample of 69,621 students attending 182 Canadian secondary schools in the 2021/22 school year. Multilevel logistic regression estimated the odds of exclusive alcohol-IDR, exclusive cannabis-IDR, and both alcohol and cannabis IDR (alcohol-cannabis-IDR). Substance use interactions with gender and age were tested. RESULTS: Overall, 14.7% of participants reported IDR; 7.5% reported exclusive alcohol-IDR, 3.2% reported exclusive cannabis-IDR, 4.0% reported alcohol-cannabis-IDR, and 7.4% were unsure if they had experienced IDR. The prevalence of IDR varied across substance use groups, 8.0% among nonuse, 21.9% among alcohol-only use, 35.9% among cannabis-only use, and 49.6% among dual use groups. Gender diverse, older, and students with lower socioeconomic status exhibited a higher likelihood of reporting alcohol-cannabis-IDR. Dual use was significantly associated with 9.5 times higher odds of alcohol-cannabis-IDR compared to alcohol-only use, and 3.0 times higher odds compared to cannabis-only use. Dual use was also associated with an increased likelihood of either alcohol- or cannabis-IDR. CONCLUSIONS: This study highlights that all students, regardless of substance use, are at risk of IDR, but students engaged in dual use of alcohol and cannabis face an elevated risk compared to both peers who do not use substances and those who use only a single substance. These findings emphasize the importance of targeted interventions that address the risks associated with IDR.

A synthetic lure for Anopheles gambiae (Diptera: Culicidae) based on the attractive plant Parthenium hysterophorus.

Sugar is the sole diet for male mosquitoes and a complementary meal for females. Searching for natural sources of sugar is mediated by semiochemicals. Floral nectars, extra floral nectaries, damaged tissues of plants and rotten fruits are the most common sources of sugar in nature. I provide laboratory evidence of the high attraction of Parthenium hysterophorus L., a weed that grows in tropical climates, to Anopheles gambiae Giles. This study has tried to identify the chemicals which might be involved in the chemical attraction of A. gambiae to this plant. Using quantitative GC-MS analysis, α-pinene, camphene, 1-octen-3-ol, ß-pinene, cis-ß-ocimene, bornyl acetate, α-caryophyllene, hexadecanoic acid, and α-linolenic acid were identified as the main constituents of P. hysterophorus volatiles. Successive olfactory assays helped a better understanding of the more attractive chemicals of P. hysterophorus to A. gambiae which was the basis for testing a possible synthetic blend. Olfactory experiments proved this synthetic blend to be as attractive as Parthenium intact plants for A. gambiae. A minimal blend, consisting of only α-pinene, camphene, and cis-ß-ocimene, was also produced and laboratory experiments indicated its relative attraction for A. gambiae. This blend can be tested in the attractive toxic sugar bait stations for sampling, surveillance, or control programs of mosquitoes in tropical Africa, where A. gambiae sensu stricto transfer malaria among residents.

Evaluating the One-Year Impact of School e-Cigarette Use Interventions among Current Youth e-Cigarette Users in the COMPASS Study, 2017/18-2018/19.

There is a lack of evidence for the impact of school-based e-cigarette interventions among current e-cigarette users. This natural experimental evaluation study evaluated the one-year impact of various school-based e-cigarette prevention/cessation programs among a sample of current youth e-cigarette users. The COMPASS study sample included n = 3586 current e-cigarette users from n = 90 schools with data collected between 2017 and 2019. Student e-cigarette use patterns were categorized as "escalated", "maintained", and "reduced" based on the change in past 30-day e-cigarette use between baseline and follow-up. Intervention schools added e-cigarette use "prevention", "cessation", or "protection" programs, while control schools did not make any changes. Logistic regression models identified how each category of added programs was associated with e-cigarette use patterns. About one quarter of schools added an e-cigarette use prevention/cessation program over one year. Student e-cigarette use patterns between control and intervention groups differed in proportion ranging from a decrease of 3.35% to an increase of 5.80%. Regression models did not identify any significant differences in the odds of escalating or reducing e-cigarette use in intervention relative to control schools. While many schools implemented new e-cigarette programs over one year, none of the interventions led to significant changes in e-cigarette escalation or reduction among current youth e-cigarette users. Additional studies are needed to evaluate the impact of e-cigarette interventions among current e-cigarette users.