1,502 research outputs found

    Group extensions problem and its resolution in cohomology for the case of an elementary abelian normal sub-group, The

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    2018 Summer.Includes bibliographical references.The Jordan-Hölder theorem gives a way to deconstruct a group into smaller groups, The converse problem is the construction of group extensions, that is to construct a group G from two groups Q and K where K ≤ G and G/K ≅ Q. Extension theory allows us to construct groups from smaller order groups. The extension problem then is to construct all extensions G, up to suitable equivalence, for given groups K and Q. This talk will explore the extension problem by first constructing extensions as cartesian products and examining the connections to group cohomology

    Examining Manual and Visual Response Inhibition Among ADHD Subtypes

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    This study compared inhibitory functioning among ADHD subtype groups on manual and visual versions of the stop task. Seventy-six children, identified as ADHD/I (n = 16), ADHD/C (n =42), and comparison (n = 18) completed both tasks. Results indicated that both ADHD groups were slower to inhibit responses than the comparison group on both tasks. Comparison children were faster to inhibit than activate responses on both versions of the task. Children in the ADHD groups also demonstrated this robust pattern on the manual task. However, on the visual task, children in the ADHD groups evidenced slowed inhibition comparable to the time required to activate responding. This implies that the visual task is more sensitive to inhibitory impairment in ADHD than the manual task. The ADHD/I group did not differ from children with ADHD/C on most measures, suggesting that the stop task is not effective in differentiating the subtypes. These findings extend work highlighting the role of disinhibition in ADHD, and contrast recent work suggesting divergence between ADHD subtypes

    The intervening role of urgency on the association between childhood maltreatment, PTSD, and substance-related problems

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    A range of risk factors lead to opioid use and substance-related problems (SRP) including childhood maltreatment, elevated impulsivity, and psychopathology. These constructs are highly interrelated such that childhood maltreatment is associated with elevated impulsivity and trauma-related psychopathology such as posttraumatic stress disorder (PTSD), and impulsivity-particularly urgency-and PTSD are related. Prior work has examined the association between these constructs and substance-related problems independently and it is unclear how these multi-faceted constructs (i.e., maltreatment types and positive and negative urgency) are associated with one another and SRP. The current study used structural equation modeling (SEM) to examine the relations among childhood maltreatment, trait urgency, PTSD symptoms, and SRP in a sample of individuals with a history of opioid use. An initial model that included paths from each type of childhood maltreatment, positive and negative urgency, PTSD and SRP did not fit the data well. A pruned model with excellent fit was identified that suggested emotional abuse, positive urgency, and negative urgency were directly related to PTSD symptoms and only PTSD symptoms were directly related to SRP. Furthermore, significant indirect effects suggested that emotional abuse and negative urgency were related to SRP via PTSD symptom severity. These results suggest that PTSD plays an important role in the severity of SRP

    Response Style Differences in the Inattentive and Combined Subtypes of Attention-Deficit/Hyperactivity Disorder

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    This study examined potential differences between the inattentive and combined ADHD subtypes using laboratory tasks assessing behavioral inhibitory processes. Seventy-five children completed two tasks of behavioral inhibition believed to isolate different processes: the cued reaction time task (CRT), a basic inhibition task, and the go/no-go task (GNG), a complex inhibition task that incorporates motivational contingencies. Three groups of participants were identified, including ADHD/Inattentive (n = 17), ADHD/Combined (n = 37), and comparison (n = 21). Results indicated that rather than showing behavioral inhibition deficits, the ADHD/I children appeared overly inhibited, as evidenced by slower reaction times across the two tasks and significantly higher errors of omission in the GNG task. Additionally, the ADHD/I children did not demonstrate cue dependency effects on the CRT task, suggesting that they were failing to incorporate relevant information before making a response. The sluggish and inhibited performance of the ADHD/I group challenges the idea that it is a subtype of ADHD

    Cue-Dependent Inhibition in Posttraumatic Stress Disorder and Attention- Deficit/Hyperactivity Disorder

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    Objective Attention-deficit/hyperactivity disorder (ADHD) and posttraumatic stress disorder (PTSD) are common among military veterans, but the comorbidity of these two psychiatric disorders remains largely unstudied. Evaluating response inhibition and cue-dependent learning as behavioral and neurocognitive mechanisms underlying ADHD/PTSD can inform etiological models and development of tailored interventions. Method A cued go/no-go task evaluated response inhibition in 160 adult males. Participants were recruited from the community and a Veterans Administration medical center. Four diagnostic groups were identified: ADHD-only, PTSD-only, ADHD + PTSD, controls. Results Group differences were observed across most indices of inhibitory functioning, reaction time, and reaction time variability, whereby PTSD-only and ADHD + PTSD participants demonstrated deficits relative to controls. No cue dependency effects were observed. Conclusion Finding complement prior work on neurocognitive mechanisms underlying ADHD, PTSD, and ADHD + PTSD. Lack of expected group differences for the ADHD-only group may be due to limited power. Additional work is needed to better characterize distinctions among clinical groups, as well as to test effects among women and youth

    Clinical Decision-Making Following Disasters: Efficient Identification of PTSD Risk in Adolescents

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    The present study aimed to utilize a Receiver Operating Characteristic (ROC) approach in order to improve clinical decision-making for adolescents at risk for the development of psychopathology in the aftermath of a natural disaster. Specifically we assessed theoretically-driven individual, interpersonal, and event-related vulnerability factors to determine which indices were most accurate in forecasting PTSD. Furthermore, we aimed to translate these etiological findings by identifying clinical cut-off recommendations for relevant vulnerability factors. Our study consisted of structured phone-based clinical interviews with 2,000 adolescent-parent dyads living within a 5-mile radius of tornados that devastated Joplin, MO, and northern Alabama in Spring 2011. Demographics, tornado incident characteristics, prior trauma, mental health, and family support and conflict were assessed. A subset of youth completed two behavioral assessment tasks online to assess distress tolerance and risk taking behavior. ROC analyses indicated four variables that significantly improved PTSD diagnostic efficiency: Lifetime depression (AUC=.90), trauma history (AUC=.76), social support (AUC=.70), and family conflict (AUC=.72). Youth were 2–3 times more likely to have PTSD if they had elevated scores on any of these variables. Of note, event-related characteristics (e.g., property damage) were not related to PTSD diagnostic status. The present study adds to the literature by making specific recommendations for empirically-based, efficient disaster-related PTSD assessment for adolescents following a natural disaster. Implications for practice and future trauma-related developmental psychopathology research are discussed

    Implementing risk stratification to the treatment of adolescent substance use among youth involved in the juvenile justice system: protocol of a hybrid type I trial

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    BACKGROUND: Youth involved in the juvenile justice system (YIJJ) have high rates of substance use problems; however, rates of YIJJ engagement in substance use services is low. Barriers to service engagement include lack of appropriate screening and connection to services by the juvenile justice system, as well as lack of resources for delivering evidence-based treatment in community-based settings. To address these barriers, this paper describes a protocol for a type 1 hybrid design to (1) implement universal substance use screening for YIJJ; (2) implement and evaluate the feasibility and effectiveness of a brief, three-session substance use interventions based in motivational interviewing for youth with mild/moderate substance use: Teen Intervene (an individual-based intervention); (3) implement ENCOMPASS, an evidence-based substance use intervention based in motivational enhancement and cognitive behavioral therapy for youth with severe substance use; and (4) evaluate facilitators and barriers to implementing these interventions for mild to severe substance use among YIJJ in community mental health centers (CMHC). METHODS/DESIGN: Using a hybrid type 1 clinical effectiveness-implementation design, we will collaborate with CMHCs and juvenile justice in two rural Indiana counties. Guided by the EPIS (exploration, preparation, implementation, sustainability) framework, we will measure factors that affect implementation of substance use screening in juvenile justice and implementation of substance use interventions in CMHCs utilizing self-reports and qualitative interviews with juvenile justice and CMHC staff pre- and post-implementation. YIJJ with mild/moderate substance use will receive a brief interventions and YIJJ with severe substance use will receive ENCOMPASS. We will measure the effectiveness of a brief and comprehensive intervention by assessing changes in substance use across treatment. We anticipate recruiting 160 YIJJ and their caregivers into the study. We will assess intervention outcomes utilizing baseline, 3-, and 6-month assessments. DISCUSSION: Findings have the potential to improve screening and intervention services for YIJJ

    The influence of droplet size and biodegradation on the transport of subsurface oil droplets during the Deepwater Horizon: a model sensitivity study

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    A better understanding of oil droplet formation, degradation, and dispersal in deep waters is needed to enhance prediction of the fate and transport of subsurface oil spills. This research evaluates the influence of initial droplet size and rates of biodegradation on the subsurface transport of oil droplets, specifically those from the Deepwater Horizon oil spill. A three-dimensional coupled model was employed with components that included analytical multiphase plume, hydrodynamic and Lagrangian models. Oil droplet biodegradation was simulated based on first order decay rates of alkanes. The initial diameter of droplets (10–300 μm) spanned a range of sizes expected from dispersant-treated oil. Results indicate that model predictions are sensitive to biodegradation processes, with depth distributions deepening by hundreds of meters, horizontal distributions decreasing by hundreds to thousands of kilometers, and mass decreasing by 92–99% when biodegradation is applied compared to simulations without biodegradation. In addition, there are two- to four-fold changes in the area of the seafloor contacted by oil droplets among scenarios with different biodegradation rates. The spatial distributions of hydrocarbons predicted by the model with biodegradation are similar to those observed in the sediment and water column, although the model predicts hydrocarbons to the northeast and east of the well where no observations were made. This study indicates that improvement in knowledge of droplet sizes and biodegradation processes is important for accurate prediction of subsurface oil spills.National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1048630)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1044573)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant CBET-1045831)Gulf of Mexico Research Initiativ

    How should we screen for depression following a natural disaster? An ROC approach to post-disaster screening in adolescents and adults

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    The present study’s aim was to provide the foundation for an efficient, empirically based protocol for depression screening following a natural disaster. Utilizing a Receiver Operating Characteristic (ROC) analytic approach, the study tested a) what specific disaster-related stressors (i.e., property damage, loss of basic services) and individual-related constructs (i.e., PTSD symptoms, trauma history, social support) conveyed the greatest risk for post-natural disaster depression, b) specific cutoff scores across these measures, and c) whether the significance or cutoff scores for each construct varied between adolescents and adults

    Meditation smartphone application effects on prehypertensive adults' blood pressure: Dose-response feasibility trial

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    OBJECTIVE: Essential hypertension (EH) is the most common chronic disease in the United States and a major cause of morbidity and mortality. Lifestyle interventions (e.g., diet, exercise, stress management) to reduce blood pressure (BP) are often complex with varying effectiveness. Breathing awareness meditation (BAM) is a stress management strategy with encouraging effects on BP, though widespread dissemination is hampered by the lack of an easy-to-use methodology to train and monitor BAM practices. A smartphone application (Tension Tamer [TT]) that implements BAM and tracks adherence has shown promise in addressing these gaps. This 6-month dose-response feasibility trial evaluated effects of the app on BP to further optimize BAM user guidelines. METHODS: Sixty-four adults with prehypertension were randomized to complete TT-guided BAM sessions for 5-, 10-, or 15-min intervals twice daily over 6 months. Continuous heart rate readings derived from the phone's video camera via reflective photoplethysmography were used as feedback and as an index of time-stamped adherence. Outcomes (resting BP, HR) were collected at baseline, 1-, 3-, and 6-months. RESULTS: Mixed modeling results showed a significant time effect for systolic BP (SBP) with a dose-response effect at Months 3 and 6. Adherence declined over time and was lowest in the 15-min dose condition, though SBP reductions were maintained. Generally, adherence was negatively associated with dose as the study progressed. CONCLUSIONS: Smartphone-implemented BAM appears to reduce SBP and can be a low-cost method to reach large populations. (PsycINFO Database Recor
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