Distributed Community Detection in Dynamic Graphs

Inspired by the increasing interest in self-organizing social opportunistic networks, we investigate the problem of distributed detection of unknown communities in dynamic random graphs. As a formal framework, we consider the dynamic version of the well-studied \emph{Planted Bisection Model} \sdG(n,p,q) where the node set $[n]$ of the network is partitioned into two unknown communities and, at every time step, each possible edge $(u,v)$ is active with probability $p$ if both nodes belong to the same community, while it is active with probability $q$ (with $q<<p$) otherwise. We also consider a time-Markovian generalization of this model. We propose a distributed protocol based on the popular \emph{Label Propagation Algorithm} and prove that, when the ratio $p/q$ is larger than $n^{b}$ (for an arbitrarily small constant $b>0$), the protocol finds the right "planted" partition in $O(\log n)$ time even when the snapshots of the dynamic graph are sparse and disconnected (i.e. in the case $p=\Theta(1/n)$).Comment: Version I

Coercive Sexual Strategies

This study examines the use of coercive sexual strategies by men and the outcomes of these behaviors for women. Using a sample of 541 college undergraduates, data were gathered from men on their use of three types of coercive sexual strategies and from women on their experiences with these same forms of behaviors. For women, there is a positive association between being sexually active, having sexually permissive attitudes, drinking alcohol and being a victim of certain types of sexual coercive strategies. For men, sexually permissive attitudes and attitudes toward rape are found to be significant predictors of their use of verbal coercion. Furthermore, being a fraternity member is associated with the use of verbal coercion and physical force and being a sorority member is associated with being a victim of alcohol/drug coercion and physical force. Reports from both men and women give a more comprehensive interpretation of the specific mechanisms through which different coercive strategies are played out

Predictors of First Mental Health Service Utilization among Homeless and Runaway Adolescents

Purpose: To describe and explain variations in first mental health service utilization before and after running away from home for homeless adolescents. Methods: Survey interviews were conducted with homeless and runaway youth in several Midwestern locations. The effects of family of origin factors and street experiences on the likelihood of seeing a mental health professional for the first time before running away and after running away for the first time were examined. Bivariate and multivariate logistic regression methods are used to analyze these data. Interactions are tested across race and gender sub-groups. Results: Caretaker education, caretaker rejection, and family transitions increase the probability that an adolescent first sees a mental health professional before running away from home. Post-run intervention is more likely for females, younger runaways, shelter users, youths with social support networks, and youths abused by their caretakers. A gender gap in first service use exists for Whites but not for minority youth. Minority youth who experienced family abuse were less likely than abused Whites to report ever seeing a mental health professional. Conclusions: Analyses indicate homeless youth’s utilization patterns are differentiated by family of origin factors, street experiences, timing of first utilization, and by race and gender interactions. Our findings suggest that youths whose first contact with mental health service use follows running away for the first time may experience higher levels of mental distress compared with other homeless runaways. The significant differences in first service use across race and gender subgroups should be further explored. The racial-ethnic gap in first mental health intervention for abused youths indicates this sub-group is not receiving services that are available to other homeless youths. Our findings suggest that homelessness does not homogenize racial/ethnic differences in first mental health service utilization

Coercive Sexual Strategies

This study examines the use of coercive sexual strategies by men and the outcomes of these behaviors for women. Using a sample of 541 college undergraduates, data were gathered from men on their use of three types of coercive sexual strategies and from women on their experiences with these same forms of behaviors. For women, there is a positive association between being sexually active, having sexually permissive attitudes, drinking alcohol and being a victim of certain types of sexual coercive strategies. For men, sexually permissive attitudes and attitudes toward rape are found to be significant predictors of their use of verbal coercion. Furthermore, being a fraternity member is associated with the use of verbal coercion and physical force and being a sorority member is associated with being a victim of alcohol/drug coercion and physical force. Reports from both men and women give a more comprehensive interpretation of the specific mechanisms through which different coercive strategies are played out

Family Risk Factors and Prevalence of Dissociative Symptoms among Homeless and Runaway Youth

Objective: To examine family risk factors associated with dissociative symptoms among homeless and runaway youth. Method: Three hundred and twenty-eight homeless and runaway youth were interviewed using a systematic sampling strategy in metropolitan Seattle. Homeless young people were interviewed on the streets and in shelters by outreach workers in youth service agencies. Results: The current study revealed widespread prevalence of dissociative symptoms among these young people. Multivariate analyses revealed that sexual abuse, physical abuse, and family mental health problems were all positively associated with dissociative symptoms. No gender differences were found for any of the models. Conclusions: Dissociative behavior is widespread among these youth and may pose a serious mental health concern. Some young people experience numerous stressors, and with few resources and little support available, many may invoke maladaptive strategies such as dissociative behavior to handle such situations, which may in turn be detrimental to their mental health. Unless youth are provided with programs and intervention, the cycle of abuse that they have experienced at home is likely to continue on the street

Correlates of bullying behaviors among a sample of North American Indigenous adolescents

The purpose of this study was to examine the relationship between familial, educational, and psychosocial factors and bullying among 702 North American Indigenous adolescents aged 11–14 years. The study used multinomial logistic regression models to differentiate correlates of bully perpetration and victimization versus being neither and between being a perpetrator versus being a victim. Analyses reveal that being a bully victim had different correlates than being a perpetrator. Perceived discrimination was associated with increased odds of being either a victim or a perpetrator, relative to being neither. Several factors differentiated being a bully perpetrator from being a bully victim: adolescent age, parental warmth and support, depressive symptoms, anger, and school adjustment. These findings expand upon the limited understanding of the factors associated with bullying among North American Indigenous youth. Bullying intervention and prevention programs that target Indigenous adolescents should be culturally grounded and begin early within the family

Correlates of bullying behaviors among a sample of North American Indigenous adolescents

The purpose of this study was to examine the relationship between familial, educational, and psychosocial factors and bullying among 702 North American Indigenous adolescents aged 11–14 years. The study used multinomial logistic regression models to differentiate correlates of bully perpetration and victimization versus being neither and between being a perpetrator versus being a victim. Analyses reveal that being a bully victim had different correlates than being a perpetrator. Perceived discrimination was associated with increased odds of being either a victim or a perpetrator, relative to being neither. Several factors differentiated being a bully perpetrator from being a bully victim: adolescent age, parental warmth and support, depressive symptoms, anger, and school adjustment. These findings expand upon the limited understanding of the factors associated with bullying among North American Indigenous youth. Bullying intervention and prevention programs that target Indigenous adolescents should be culturally grounded and begin early within the family

The Effects of a High-Risk Environment on the Sexual Victimization of Homeless and Runaway Youth

Based on the structural-choice theory of victimization, the current study examines the effects of a high-risk environment on the sexual victimization of 311 homeless and runaway youth. Results from logistic regression revealed that survival sex, gender, and physical appearance were significantly associated with sexual victimization. Results from a series of interactions also revealed that the effects of deviant behaviors on sexual victimization varied by gender and age. Although males and females engaged in similar activities, young women were more likely to be victims of sexual assault. These findings suggest that engaging in high-risk behaviors predispose some people to greater risks but it is the combination of these behaviors with gender and/or age that determines who will become victimized

Familial and “On-the-Street” Risk Factors Associated with Alcohol Use among Homeless and Runaway Adolescents

Objective: This study investigated factors associated with alcohol use among homeless and runaway adolescents, using a risk amplification model.Method: Homeless and runaway adolescents (N = 536, 60% female) were recruited and interviewed by outreach workers directly on the streets, in shelters and in drop-in centers in four Midwestern states. The average age was 16 years; ages ranged from 12 to 22. Results: Parent alcohol problems were indirectly linked to adolescent drinking through familial abuse and its relationship to deviant peers, time on own and risky subsistence behaviors. Parent alcohol problems also predicted offspring alcohol use through parental rejection and its association with deviant peers and with risky subsistence behaviors. The strongest direct effects on alcohol use were hanging out with antisocial friends and participating in deviant behaviors in order to survive on the street. Conclusions: This study sheds light on the nature of alcohol use in a high-risk population. Family background and “on-the-street” (time on own) factors must be taken into consideration when treating alcohol misuse in street youth. The alternative is a vicious cycle whereby homeless youth may become homeless adults

A Dimensional Model of Psychopathology Among Homeless Adolescents: Suicidality, Internalizing, and Externalizing Disorders

The present study examined associations among dimensions of suicidality and psychopathology in a sample of 428 homeless adolescents (56.3% female). Confirmatory factor analysis results provided support for a three-factor model in which suicidality (measured with lifetime suicidal ideation and suicide attempts), internalizing disorders (assessed with lifetime diagnoses of major depressive episode and post-traumatic stress disorder), and externalizing disorders (indicated by lifetime diagnoses of conduct disorder, alcohol abuse, and drug abuse) were positively intercorrelated. The findings illustrate the utility of a dimensional approach that integrates suicidality and psychopathology into one model