No abstract

The objective of the present study was to examine prospective, bidirectional associations among posttraumatic stress disorder (PTSD) symptoms, coping style, and alcohol involvement (use, consequences), in a sample of trauma-exposed students just entering college. We also sought to test the mechanistic role that coping may play in associations between PTSD symptoms and problem alcohol involvement over time. Participants (N=734) completed measures of trauma exposure, PTSD symptoms, coping, and alcohol use and consequences in September of their first college year (Y1) and again each September for the next two years (Y2–3). We observed reciprocal associations between PTSD and negative coping strategies. In our examination of a mediated pathway through coping, we found an indirect association from alcohol consequences and PTSD symptoms via negative coping, suggesting that alcohol consequences may exacerbate posttraumatic stress over time by promoting negative coping strategies. Trauma characteristics such as type (interpersonal vs. non-interpersonal) and trauma re-exposure did not moderate these pathways. Models also were invariant across gender. Findings from the present study point to risk that is conferred by both PTSD and alcohol consequences for using negative coping approaches, and through this, for posttraumatic stress. Interventions designed to decrease negative coping may help to offset this risk, leading to more positive outcomes for those students who enter college with trauma exposure.

Women who enter college with a sexual victimization (SV) history may be at particular risk for deleterious outcomes including maladaptive alcohol involve posttraumatic stress, and re-victimization. Further, pre-college SV may be an impediment for the achievement of academic mile and may negatively impact the transition into college. Recent work shows that the method of coercion used in SV may be an important predictor of post-victimization outcomes. As such, the identification of pathways between type of SV and outcomes can aid in early identification and intervention for those at highest risk. In a sample of newly-matriculated female college students, this study examined unique outcomes associated with two specific types of SV, (1) threats/use of physical force (Force SV) or (2) incapacitation (Incap SV). Participants completed assessments of SV, alcohol involvement, posttraumatic stress, and academic outcomes at 6 time-points over their first year of college. Results showed differential outcomes based on pre-matriculation exposure to Force SV or Incap SV. Women with Incap SV were higher on problem drinking indices whereas women with Force SV were at greater risk for re-victimization and marginally more PTSD symptoms. Having a history of either type of SV predicted attrition, but there were no differences when comparing Force SV to Incap SV. Overall, results from this study support the utility of delineating SV experiences by method of coercion, and point to the potential of highlighting different outcomes in tailored intervention programs.

Background and Objectives Posttraumatic stress symptoms (PTSD) and problem alcohol use (ALC) commonly co-occur, but the nature of this co-occurrence is unclear. Self-medication explanations have been forwarded, yet traits such as tendency toward negative emotionality and behavioral disconstraint also have been implicated. In this study we test three competing models (self-medication, trait vulnerability, combined dual pathway) of PTSD-ALC prospectively in a college sample. Method Participants (N=659; 73% female, M age=18) provided data at college matriculation (Time 1) and one year later (Time 2). Results Structural equation models showed disconstraint to meditate the path from PTSD symptoms to alcohol problems, supporting a trait vulnerability conceptualization. Findings regarding negative emotionality and self-medication were more mixed. Negative emotionality played a stronger role in cross-sectional than in prospective analyses, suggesting the importance of temporal proximity. Conclusions and Scientific Significance Self-regulation skills may be an important focus for clinicians treating PTSD symptoms and alcohol misuse disorders concurrently.

This paper addresses the problem of simultaneous localization and mapping (SLAM) using vision-based sensing. We present and analyse an implementation of a RaoBlackwellised particle filter (RBPF) that uses stereo vision to localize a camera and 3D landmarks as the camera moves through an unknown environment. Our implementation is robust, can operate in real-time, and can operate without odometric or inertial measurements. Furthermore, our approach supports a 6-degree-of-freedom pose representation, vision-based ego-motion estimation, adaptive resampling, monocular operation, and a selection of odometry-based, observation-based, and mixture (combining local and global pose estimation) proposal distributions. This paper also examines the run-time behavior of efficiently designed RBPFs, providing an extensive empirical analysis of the memory and processing characteristics of RBPFs for vision-based SLAM. Finally, we present experimental results demonstrating the accuracy and efficiency of our approach.