Reliability-Based Design of Thermal Protection Systems with Support Vector Machines

The primary objective of this work was to develop a computationally efficient and accurate approach to reliability analysis of thermal protection systems using support vector machines. An adaptive sampling approach was introduced informs a iterative support vector machine approximation of the limit state function used for measuring reliability. The proposed sampling approach efficient adds samples along the limit state function until the reliability approximation is converged. This methodology is applied to two samples, mathematical functions to test and demonstrate the applicability. Then, the adaptive sampling-based support vector machine approach is applied to the reliability analysis of a thermal protection system. The results of all three problems highlight the potential capability of the new approach in terms of accuracy and computational saving in determining thermal protection system reliability

Calibration Probe Uncertainty and Validation for the Hypersonic Material Environmental Test System

This paper presents an uncertainty analysis of the stagnation-point calibration probe surface predictions for conditions that span the performance envelope of the Hypersonic Materials Environmental Test System facility located at NASA Langley Research Center. A second-order stochastic expansion was constructed over 47 uncertain parameters to evaluate the sensitivities, identify the most significant uncertain variables, and quantify the uncertainty in the stagnation-point heat flux and pressure predictions of the calibration probe for a low- and high-enthalpy test condition. A sensitivity analysis showed that measurement bias uncertainty is the most significant contributor to the stagnation-point pressure and heat flux variance for the low-enthalpy condition. For the high-enthalpy condition, a paradigm shift in sensitivities revealed the computational fluid dynamics model input uncertainty as the main contributor. A comparison between the prediction and measurement of the stagnation-point conditions under uncertainty showed that there was evidence of statistical disagreement. A validation metric was proposed and applied to the prediction uncertainty to account for the statistical disagreement when compared to the possible stagnation-point heat flux and pressure measurements

Mental Health Screenings in Juvenile Detention Centers: Predictors of Mental Health Service Utilization and Recidivism

poster abstractIntroduction: About 2 in 3 detained adolescents meet criteria for mental illness. Unfortunately, the juvenile justice system does not consistently provide mental health services for juveniles in need. As a result, juvenile adolescents have low rates of treatment utilization, high rates of recidivism, and a mortality rate 4 times greater than the general population. To understand these issues, the current study tracked a sample of detained adolescents for six months post-detention. Methods: 2089 adolescents held in a detention center completed a mental health screener. The prevalence of youths with different mental health problems was calculated. Logistic regression analyses were conducted to determine predictors of service utilization and recidivism at 3- and 6-month follow-up. Results: Altogether, 1707 (81.7%) reported trauma, 561 (26.9%) endorsed alcohol/drug use, and 393 (18.8%) endorsed significant thought disturbances. Post-detention, 336 (16.1%) utilized mental health services and 770 (36.9%) re-offended. Regression analyses indicated: (1) Hispanic youths, males, and older youths were significantly less likely to utilize services (OR=.37, p=.015 for Hispanic; OR=.53, p <.001 for males; OR=.842, p <.001 for older); (2) youths with anger problems were more likely to utilize services (OR=1.08, p=.011); (3) racial/ethnic minorities were significantly more likely to recidivate (OR=1.12, p=.009); (4) alcohol/drug use increased the likelihood of recidivism (OR=1.12, p<.001); and (5) youths who utilized services were no less likely to recidivate (OR=1.22, p=.116). Conclusions: Juveniles with mental illness problems are not getting the treatment services they need. Furthermore, Hispanic, male, and older youths were less likely to utilize services, minority youths were more likely to be re-arrested, and service use did not impact recidivism. Findings suggest gaps and disparities in mental health services for juvenile adolescents. The juvenile justice system needs to improve public policies and develop mechanisms to ensure all juveniles have an equal opportunity to receive effective mental health services

Why stellar feedback promotes disc formation in simulated galaxies

We study how feedback influences baryon infall onto galaxies using cosmological, zoom-in simulations of haloes with present mass $M_{vir}=6.9\times10^{11} M_{\odot}$ to $1.7\times10^{12} M_{\odot}$. Starting at z=4 from identical initial conditions, implementations of weak and strong stellar feedback produce bulge- and disc-dominated galaxies, respectively. Strong feedback favours disc formation: (1) because conversion of gas into stars is suppressed at early times, as required by abundance matching arguments, resulting in flat star formation histories and higher gas fractions; (2) because 50% of the stars form in situ from recycled disc gas with angular momentum only weakly related to that of the z=0 dark halo; (3) because late-time gas accretion is typically an order of magnitude stronger and has higher specific angular momentum, with recycled gas dominating over primordial infall; (4) because 25-30% of the total accreted gas is ejected entirely before z~1, removing primarily low angular momentum material which enriches the nearby inter-galactic medium. Most recycled gas roughly conserves its angular momentum, but material ejected for long times and to large radii can gain significant angular momentum before re-accretion. These processes lower galaxy formation efficiency in addition to promoting disc formation.Comment: 23 pages, 29 figures, accepted for publication in MNRA

Parents Served by Assertive Community Treatment: A Needs Based Assessment

poster abstractAssertive Community Treatment (ACT) represents an effective treatment for individuals with severe mental illness. Though studies estimate roughly half of all people with severe mental illness are parents, little is known about consumers receiving ACT services who are parents. Thus, the purpose of the present study was to 1) estimate the prevalence of parent ACT consumers, 2) identify current ACT team policies and services for parent consumers, and 3) examine the perspective of parent consumers served by ACT teams. Quantitative and qualitative data were collected and analyzed via two studies. In study 1, 82 ACT providers from 76 teams in the US and Canada were surveyed. Providers estimated roughly 21.6% of ACT consumers were parents. Only 46.3% of providers reported formally asking consumers about parental status and 20.7% of providers belonged to ACT teams that offer services designed for parent consumers. The majority of providers (75.6%) reported negative or mixed attitudes about parents with severe mental illness. In study 2, seventeen parents receiving ACT services were interviewed. All parents endorsed positive attitudes about parenting, though most (76.5%) also identified negative aspects of parenting. Almost all parents (88.2%) reported loss of custody at least once. Parents expressed interest in parent-focused treatment services like family therapy, parenting skills, communication skills training, and peer support groups. Regarding satisfaction with ACT services, most parents with adult children (87.5%) reported no unmet parent-related needs and high satisfaction (4.63 of 5) with ACT services, whereas parents with young children (77.8%) reported unmet parenting needs and low satisfaction (3.78 of 5) with ACT services. Thus, results indicate the ACT treatment model may not be adequately serving parents with young, dependent children. Overall, findings suggest the need for more focus on parents with severe mental illness, including formal identification of parental status and parent-related treatment services and support

Modelling the dynamics of intramammary E. coli infections in dairy cows: understanding mechanisms that distinguish transient from persistent infections

The majority of intramammary infections with Escherichia coli in dairy cows result in transient infections with duration of about 10 days or less, although more persistent infections (2 months or longer) have been identified. We apply a mathematical model to explore the role of an intracellular mammary epithelial cell reservoir in the dynamics of infection. We included biological knowledge of the bovine immune response and known characteristics of the bacterial population in both transient and persistent infections. The results indicate that varying the survival duration of the intracellular reservoir reproduces the data for both transient and persistent infections. Survival in an intracellular reservoir is the most likely mechanism that ensures persistence of E. coli infections in mammary glands. Knowledge of the pathogenesis of persistent infections is essential to develop preventive and treatment programmes for these important infections in dairy cows

Detained Adolescents: Mental Health Needs, Treatment Use, and Recidivism

Objective: Although approximately 60%-70% of detained adolescents meet criteria for a mental disorder, few receive treatment upon community reentry. Given that mental health treatment can potentially reduce recidivism, the study examined detained adolescents’ mental health needs and their post-detention mental health treatment and recidivism. Method: Altogether, 1574 adolescents (<18 years) completed a mental health screener at a detention center. Scores on the screener, mental health treatment utilization (60-days post-detention), and recidivism (6-months post-detention) were measured. Results: About 82.2% of adolescents earned elevated scores on the mental health screener, but only 16.4% utilized treatment and 37.2% recidivated. Logistic regression models revealed adolescents with insurance and higher Angry-Irritable scores were significantly more likely to obtain treatment, whereas males, Black adolescents, older adolescents, and adolescents endorsing a trauma history were less likely. Black adolescents, insured adolescents, and adolescents with higher Alcohol/Drug Use scores were significantly more likely to recidivate. Mental health treatment increased the likelihood of recidivism. Discussion: The prevalence of mental health needs among DAs was high, but treatment utilization was low, with notable treatment disparities across race, gender, and age. The use of mental health treatment predicted recidivism, suggesting treatment may act as a proxy measure of mental health problems. Future research should assess the impact of timely and continuous mental health services on recidivism

Shifting food consumption to mitigate climate change is critical to fulfilling the Paris Agreement, but how?

Reducing emissions by changing consumption of foods with large greenhouse gas emissions could have a major impact on climate change. Yet past efforts to change diets through public policy have had mixed results, suggesting that recent estimates of technical mitigation potential likely exceed feasible reductions in emissions. Shifting consumption away from livestock products is a major opportunity for reducing emissions driven by consumption demand. In some contexts, this could also provide health, food security and other environmental benefits. Packages of policy mechanisms and interventions involving health, nutrition, efficiency and sustainability in supply chains will be more effective in achieving dietary change than any one measure. Focusing on reducing food loss and waste in high potential areas and involving key value chain actors can increase returns on efforts to mitigate climate change and improve food security. Private sector investment in reducing food loss and waste requires an enabling environment, support for development of commercially viable investments, and increased awareness among financial institutions of investment opportunities. This Info Note is related to the report on "The technical mitigation potential of demand-side measures in the agri-food sector: a preliminary assessment of available measures" https://cgspace.cgiar.org/bitstream/handle/10568/77142/CCAFS%20Report%2015%20for%20web.pd

The “Critical” Elements of Illness Management and Recovery: Comparing Methodological Approaches

This study examined three methodological approaches to defining the critical elements of Illness Management and Recovery (IMR), a curriculum-based approach to recovery. Sixty-seven IMR experts rated the criticality of 16 IMR elements on three dimensions: defining, essential, and impactful. Three elements (Recovery Orientation, Goal Setting and Follow-up, and IMR Curriculum) met all criteria for essential and defining and all but the most stringent criteria for impactful. Practitioners should consider competence in these areas as preeminent. The remaining 13 elements met varying criteria for essential and impactful. Findings suggest that criticality is a multifaceted construct, necessitating judgments about model elements across different criticality dimensions