400 research outputs found

    The structure of gravel-bed flow with intermediate submergence: a laboratory study

    Get PDF
    The paper reports an experimental study of the flow structure over an immobile gravel bed in open channel at intermediate submergence, with particular focus on the near-bed region. The experiments consisted of velocity measurements using three-component (stereoscopic) Particle Image Velocimetry (PIV) in near-bed horizontal plane and two-component PIV in three vertical planes that covered three distinctly different hydraulic scenarios where the ratio of flow depth to roughness height (i.e., relative submergence) changes from 7.5 to 10.8. Detailed velocity measurements were supplemented with fine-scale bed elevation data obtained with a laser scanner. The data revealed longitudinal low-momentum and high-momentum "strips'' in the time-averaged velocity field, likely induced by secondary currents. This depth-scale pattern was superimposed with particle-scale patches of flow heterogeneity induced by gravel particle protrusions. A similar picture emerged when considering second-order velocity moments. The interaction between the flow field and gravel-bed protrusions is assessed using cross correlations of velocity components and bed elevations in a horizontal plane just above gravel particle crests. The cross correlations suggest that upward and downward fluid motions are mainly associated with upstream-facing and lee sides of particles, respectively. Results also show that the relative submergence affects the turbulence intensity profiles for vertical velocity over the whole flow depth, while only a weak effect, limited to the near-bed region, is noticed for streamwise velocity component. The approximation of mean velocity profiles with a logarithmic formula reveals that log-profile parameters depend on relative submergence, highlighting inapplicability of a conventional "universal'' logarithmic law for gravel-bed flows with intermediate submergence

    A novel experimental technique and its application to study the effects of particle density and flow submergence on bed particle saltation

    Get PDF
    This research was sponsored by EPSRC grant EP/G056404/1 which is greatly appreciated.Peer reviewedPublisher PD

    Adaptive Mobile Health Intervention for Adolescents with Asthma: Iterative User-Centered Development

    Get PDF
    Background: Adolescents diagnosed with persistent asthma commonly take less than 50% of their prescribed inhaled corticosteroids (ICS), placing them at risk for asthma-related morbidity. Adolescents’ difficulties with adherence occur in the context of normative developmental changes (eg, increased responsibility for disease management) and rely upon still developing self-regulation and problem-solving skills that are integral for asthma self-management. We developed an adaptive mobile health system, Responsive Asthma Care for Teens (ReACT), that facilitates self-regulation and problem-solving skills during times when adolescents’ objectively measured ICS adherence data indicate suboptimal rates of medication use. Objective: The current paper describes our user-centered and evidence-based design process in developing ReACT. We explain how we leveraged a combination of individual interviews, national crowdsourced feedback, and an advisory board comprised of target users to develop the intervention content. Methods: We developed ReACT over a 15-month period using one-on-one interviews with target ReACT users (n=20), national crowdsourcing (n=257), and an advisory board (n=4) to refine content. Participants included 13-17–year-olds with asthma and their caregivers. A total of 280 adolescents and their caregivers participated in at least one stage of ReACT development. Results: Consistent with self-regulation theory, adolescents identified a variety of salient intrapersonal (eg, forgetfulness, mood) and external (eg, changes in routine) barriers to ICS use during individual interviews. Adolescents viewed the majority of ReACT intervention content (514/555 messages, 93%) favorably during the crowdsourcing phase, and the advisory board helped to refine the content that did not receive favorable feedback during crowdsourcing. Additionally, the advisory board provided suggestions for improving additional components of ReACT (eg, videos, message flow). Conclusions: ReACT involved stakeholders via qualitative approaches and crowdsourcing throughout the creation and refinement of intervention content. The feedback we received from participants largely supported ReACT’s emphasis on providing adaptive and personalized intervention content to facilitate self-regulation and problem-solving skills, and the research team successfully completed the recommended refinements to the intervention content during the iterative development process

    Responsive Asthma Care for Teens (ReACT): Development protocol for an adaptive mobile health intervention for adolescents with asthma

    Get PDF
    This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Introduction Asthma is a leading cause of youth morbidity in the USA, affecting >8% of youth. Adherence to inhaled corticosteroids (ICS) can prevent asthma-related morbidity; however, the typical adolescent with asthma takes fewer than 50% of their prescribed doses. Adolescents are uniquely vulnerable to suboptimal asthma self-management due to still-developing executive functioning capabilities that may impede consistent self-regulation and weaken attempts to use problem solving to overcome barriers to ICS adherence. Methods and analysis The aims of this project are to improve adherence to ICS as an important step towards better self-management among adolescents aged 13–17 years diagnosed with asthma by merging the efficacious behaviour change strategies found in behavioural health interventions with scalable, adaptive mobile health (mHealth) technologies to create the Responsive Asthma Care for Teens programme (ReACT). ReACT intervention content will be developed through an iterative user-centred design process that includes conducting (1) one-on-one interviews with 20 teens with asthma; (2) crowdsourced feedback from a nationally representative panel of 100 adolescents with asthma and (3) an advisory board of youth with asthma, a paediatric pulmonologist and a behavioural health expert. In tandem, we will work with an existing technology vendor to programme ReACT algorithms to allow for tailored intervention delivery. We will conduct usability testing of an alpha version of ReACT with a sample of 20 target users to assess acceptability and usability of our mHealth intervention. Participants will complete a 4-week run-in period to monitor their adherence with all ReACT features turned off. Subsequently, participants will complete a 4-week intervention period with all ReACT features activated. The study started in October 2018 and is scheduled to conclude in late 2019. Ethics and dissemination Institutional review board approval was obtained at the University of Kansas and the University of Florida. We will submit study findings for presentation at national research conferences that are well attended by a mix of psychologists, allied health professionals and physicians. We will publish study findings in peer-reviewed journals read by members of the psychology, nursing and pulmonary communities

    A five-sample confirmatory factor analytic study of burnout-depression overlap

    Full text link
    Objective: It has been asserted that burnout—a condition ascribed to unresolvable job stress—should not be mistaken for a depressive syndrome. In this confirmatory factor analytic study, the validity of this assertion was examined. Methods: Five samples of employed individuals, recruited in Switzerland and France, were mobilized for this study (N = 3,113). Burnout symptoms were assessed with the Shirom–Melamed Burnout Measure, the Maslach Burnout Inventory (MBI)—General Survey, and the MBI for Educators. Depressive symptoms were measured with the PHQ‐9. Results: In all five samples, the latent factors pertaining to burnout’s components correlated on average more highly with the latent Depression factor than with each other, even with fatigue‐related items removed from the PHQ‐9. Second‐order factor analyses indicated that the latent Depression factor and the latent factors pertaining to burnout’s components were reflective of the same overarching factor. Conclusions: This study suggests that the burnout-depression distinction is artificial

    Process evaluation for complex interventions in primary care: understanding trials using the normalization process model

    Get PDF
    Background: the Normalization Process Model is a conceptual tool intended to assist in understanding the factors that affect implementation processes in clinical trials and other evaluations of complex interventions. It focuses on the ways that the implementation of complex interventions is shaped by problems of workability and integration.Method: in this paper the model is applied to two different complex trials: (i) the delivery of problem solving therapies for psychosocial distress, and (ii) the delivery of nurse-led clinics for heart failure treatment in primary care.Results: application of the model shows how process evaluations need to focus on more than the immediate contexts in which trial outcomes are generated. Problems relating to intervention workability and integration also need to be understood. The model may be used effectively to explain the implementation process in trials of complex interventions.Conclusion: the model invites evaluators to attend equally to considering how a complex intervention interacts with existing patterns of service organization, professional practice, and professional-patient interaction. The justification for this may be found in the abundance of reports of clinical effectiveness for interventions that have little hope of being implemented in real healthcare setting

    Improvement of a System for Catchment, Pretreatment and Treatment of Runoff Water Using PIV Tests and Numerical Simulation

    Get PDF
    This paper studies how to improve the efficiency of a new system for catchment, pretreatment, and treatment of runoff water (SCPT). This system is integrated into an urban sustainable gravity settler that can decrease diffusive pollution. This study provides important advantages for the ecosystem by improving new sustainable drainage to clean runoff water. In this paper, an investigation methodology known as hybrid engineering (HE) was used. HE combines experimental tests and numerical simulations, both of them conducted on a 1:4-scale prototype. In this study, numerical simulations by the finite-volume method (FVM) and experimental tests by particle image velocimetry (PIV) were compared. A strong correlation between the numerical and experimental analysis was found. Next, the efficiency of the SCPTwas optimized by design of experiments (DOE). Analysis of experimental and numerical results and their comparison are presented in this paper.The authors wish to express their gratitude to the Spanish Ministry of Economy and Competitiveness for the research project BIA2009-08272 funding

    Improving Coping Skills for Self-management of Treatment Side Effects Can Reduce Antiretroviral Medication Nonadherence among People Living with HIV

    Get PDF
    BackgroundHuman immunodeficiency virus (HIV) treatment side effects have a deleterious impact on treatment adherence, which is necessary to optimize treatment outcomes including morbidity and mortality.PurposeTo examine the effect of the Balance Project intervention, a five-session, individually delivered HIV treatment side effects coping skills intervention on antiretroviral medication adherence.MethodsHIV+ men and women (N = 249) on antiretroviral therapy (ART) with self-reported high levels of ART side effect distress were randomized to intervention or treatment as usual. The primary outcome was self-reported ART adherence as measured by a combined 3-day and 30-day adherence assessment.ResultsIntent-to-treat analyses revealed a significant difference in rates of nonadherence between intervention and control participants across the follow-up time points such that those in the intervention condition were less likely to report nonadherence. Secondary analyses revealed that intervention participants were more likely to seek information about side effects and social support in efforts to cope with side effects.ConclusionsInterventions focusing on skills related to ART side-effects management show promise for improving ART adherence among persons experiencing high levels of perceived ART side effects

    Characteristics of effective psychological treatments of depression: A metaregression analysis.

    Get PDF
    Although many meta-analyses have shown that psychological therapies are effective in the treatment of depression, no comprehensive metaregression analysis has been conducted to examine which characteristics of the intervention, target population, and study design are related to the effects. The authors conducted such a metaregression analysis with 83 studies (135 comparisons) in which a psychological treatment was compared with a control condition. The mean effect size of all comparisons was 0.69 (95% confidence interval = 0.60-0.79). In multivariate analyses, several variables were significant: Studies using problem-solving interventions and those aimed at women with postpartum depression or specific populations had higher effect sizes, whereas studies with students as therapists, those in which participants were recruited from clinical populations and through systematic screening, and those using care-as-usual or placebo control groups had lower effect sizes
    corecore