Estimating spillovers using imprecisely measured networks

In many experimental contexts, whether and how network interactions impact the outcome of interest for both treated and untreated individuals are key concerns. Networks data is often assumed to perfectly represent these possible interactions. This paper considers the problem of estimating treatment effects when measured connections are, instead, a noisy representation of the true spillover pathways. We show that existing methods, using the potential outcomes framework, yield biased estimators in the presence of this mismeasurement. We develop a new method, using a class of mixture models, that can account for missing connections and discuss its estimation via the Expectation-Maximization algorithm. We check our method's performance by simulating experiments on real network data from 43 villages in India. Finally, we use data from a previously published study to show that estimates using our method are more robust to the choice of network measure

Quantifying stretching and rearrangement in epithelial sheet migration

Although understanding the collective migration of cells, such as that seen in epithelial sheets, is essential for understanding diseases such as metastatic cancer, this motion is not yet as well characterized as individual cell migration. Here we adapt quantitative metrics used to characterize the flow and deformation of soft matter to contrast different types of motion within a migrating sheet of cells. Using a Finite-Time Lyapunov Exponent (FTLE) analysis, we find that - in spite of large fluctuations - the flow field of an epithelial cell sheet is not chaotic. Stretching of a sheet of cells (i.e., positive FTLE) is localized at the leading edge of migration. By decomposing the motion of the cells into affine and non-affine components using the metric D$^{2}_{min}$, we quantify local plastic rearrangements and describe the motion of a group of cells in a novel way. We find an increase in plastic rearrangements with increasing cell densities, whereas inanimate systems tend to exhibit less non-affine rearrangements with increasing density.Comment: 21 pages, 7 figures This is an author-created, un-copyedited version of an article accepted for publication in the New Journal of Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1367-2630/15/2/02503

Mental health challenges among adolescents living with HIV

Introduction: Mental health is a critical and neglected global health challenge for adolescents infected with HIV. The prevalence of mental and behavioural health issues among HIV-infected adolescents may not be well understood or addressed as the world scales up HIV prevention and treatment for adolescents. The objective of this narrative review is to assess the current literature related to mental health challenges faced by adolescents living with HIV, including access to mental health services, the role of mental health challenges during transition from paediatric to adult care services and responsibilities, and the impact of mental health interventions., Methods: For each of the topics included in this review, individual searches were run using Medline and PubMed, accompanied by scans of bibliographies of relevant articles. The topics on which searches were conducted for HIV-infected adolescents include depression and anxiety, transition from paediatric to adult HIV care and its impact on adherence and mental health, HIV-related, mental health services and interventions, and the measurement of mental health problems. Articles were included if the focus was consistent with one of the identified topics, involved HIV-infected adolescents, and was published in English., Results and Discussion: Mental and behavioural health challenges are prevalent in HIV-infected adolescents, including in resource-limited settings where most of them live, and they impact all aspects of HIV prevention and treatment. Too little has been done to measure the impact of mental health challenges for adolescents living with HIV, to evaluate interventions to best sustain or improve the mental health of this population, or to create healthcare systems with personnel or resources to promote mental health., Conclusions: Mental health issues should be addressed proactively during adolescence for all HIV-infected youth. In addition, care systems need to pay greater attention to how mental health support is integrated into the care management for HIV, particularly throughout lifespan changes from childhood to adolescence to adulthood. The lack of research and support for mental health needs in resource-limited settings presents an enormous burden for which cost-effective solutions are urgently needed

The Zwitterionic Cell Wall Teichoic Acid of Staphylococcus aureus Provokes Skin Abscesses in Mice by a Novel CD4+ T-Cell-Dependent Mechanism

Zwitterionic polysaccharide (ZPS) components of the bacterial cell envelope have been shown to exert a major histocompatibility complex (MHC) II-dependent activation of CD4+ T cells, which in turn can modulate the outcome and progression of infections in animal models. We investigated the impact of zwitterionic cell wall teichoic acid (WTA) produced by Staphylococcus aureus on the development of skin abscesses in a mouse model. We also compared the relative biological activities of WTA and capsular polysaccharide (CP), important S. aureus pathogenicity factors, in abscess formation. Expression of both WTA and CP markedly affected the ability of S. aureus to induce skin abscess formation in mice. Purified wild-type zwitterionic WTA was more active in inducing abscess formation than negatively charged mutant WTA or purified CP8. To assess the ability of purified native WTA to stimulate T cell proliferation in vitro, we co-cultivated WTA with human T-cells and antigen presenting cells in the presence and absence of various inhibitors of MHC-II presentation. Wild-type WTA induced T cell proliferation to a significantly greater extent than negatively charged WTA. T cell activation was dependent on the presentation of WTA on MHC II, since inhibitors of MHC II-dependent presentation and antibodies to MHC II significantly reduced T cell proliferation. T cells activated in vitro with wild-type WTA, but not negatively charged WTA, induced abscess formation when injected subcutaneously into wild-type mice. CD4−/− mice similarly injected with WTA failed to develop abscesses. Our results demonstrate that the zwitterionic WTA of S. aureus induces CD4+ T-cell proliferation in an MHCII-dependent manner, which in turn modulates abscess formation in a mouse skin infection model. An understanding of this novel T cell-dependent host response to staphylococcal abscess formation may lead to the development of new strategies to combat S. aureus skin and soft tissue infections

Work-related correlates of occupational sitting in a diverse sample of employees in Midwest metropolitan cities

The worksite serves as an ideal setting to reduce sedentary time. Yet little research has focused on occupational sitting, and few have considered factors beyond the personal or socio-demographic level. The current study i) examined variation in occupational sitting across different occupations, ii) explored whether worksite level factors (e.g., employer size, worksite supports and policies) may be associated with occupational sitting. Between 2012 and 2013, participants residing in four Missouri metropolitan areas were interviewed via telephone and provided information on socio-demographic characteristics, schedule flexibility, occupation, work related factors, and worksite supports and policies. Occupational sitting was self-reported (daily minutes spent sitting at work), and dichotomized. Occupation-stratified analyses were conducted to identify correlates of occupational sitting using multiple logistic regressions. A total of 1668 participants provided completed data. Those employed in business and office/administrative support spent more daily occupational sitting time (median 330 min) compared to service and blue collar employees (median 30 min). Few worksite supports and policies were sitting specific, yet factors such as having a full-time job, larger employer size, schedule flexibility, and stair prompt signage were associated with occupational sitting. For example, larger employer size was associated with higher occupational sitting in health care, education/professional, and service occupations. Work-related factors, worksite supports and policies are associated with occupational sitting. The pattern of association varies among different occupation groups. This exploratory work adds to the body of research on worksite level correlates of occupational sitting. This may provide information on priority venues for targeting highly sedentary occupation groups

Examining the Antecedent Role of Movement Proficiency in Child Development: Study Protocol

Background: Decades of research, largely from associational studies, show that the relationships of movement proficiency with the cognitive and social aspects of development are particularly strong in early childhood. Children who move proficiently tend to have better cognitive skills and social behaviors. However, the mechanisms that underpin these relationships remain unclear and research that explores causation is necessary. This study will explore the antecedent role of movement proficiency in the cognitive and social domains of child development, by examining whether a targeted movement skills training program facilitates improvements in cognitive and social skills. Methods: A group-randomized controlled trial will be conducted, implementing a fundamental movement skills training program in Hong Kong kindergartens. Participants will consist of children aged 3–5 years (N = 158) who will be randomly allocated by class to either a training or active control condition. The training program (10 weeks × 2 bouts) will be informed by an error-reduced approach to skills learning, which will involve careful design and manipulation of equipment and training environment to minimize practice errors. The active control condition will consist of typical movement activities implemented in the kindergartens in the context of the local curriculum guide. Outcomes will be measured using standardized tests of gross motor skills proficiency, executive functioning, and social skills. Measurements will occur at baseline, mid-training, post-training, and follow-up. Latent variable longitudinal modeling will be used to analyze changes in the outcomes, with covariates that include sex, body composition, fine motor skills, and physical activity. Expected Results: The findings will subsequently be reported consistent with the Consolidated Standards of Reporting Trials (CONSORT) statement. Contributions to knowledge and understanding of child development are expected, through evidence of causal mechanisms surrounding the relationship of motor with cognitive and social development. The findings will also inform policy and practice related to early childhood development and education

Assessing lifetime stressor exposure in sport performers:Associations with trait stress appraisals, health, well-being, and performance

Research has found that greater lifetime stressor exposure increases the risk for mental and physical health problems. Despite this, few studies have examined how stressors occurring over the entire lifespan affect sport performers’ health, well-being, and performance, partly due to the difficulty of assessing lifetime stressor exposure. To address this issue, we developed a sport-specific stress assessment module (Sport SAM) for the Stress and Adversity Inventory (STRAIN) and then analyzed the instrument’s usability, acceptability, validity, and test-retest reliability. Furthermore, we examined whether trait-like tendencies to appraise stressful situations as a challenge or threat mediated the association between lifetime stressor exposure and health, well-being, and performance. Participants were 395 sport performers (M(age) = 22.50 years, SD = 5.33) who completed an online survey. Results revealed that the Sport SAM demonstrated good usability and acceptability, good concurrent validity in relation to the Adult STRAIN (rs = 0.23 to 0.29), and very good test-retest reliability (r(icc) = 0.87 to 0.89). Furthermore, the Sport SAM was significantly associated with symptoms of depression (β = 0.21 to 0.24, ps ≤ .001) and anxiety (β = 0.13 to 0.19, ps ≤ .012), and general physical (β = 0.24 to 0.27, ps = ≤ 0.001) and mental (β = 0.23 to 0.32, p ≤ .001) health complaints. Finally, we found that associations between total lifetime non-sport and sport-specific stressor severity and health were mediated by trait stress appraisals. Consequently, these findings may help practitioners better identify sport performers who are at risk of developing stress-related health problems

Using Global Positioning System Technology to Manage Human-Black Bear Incidents at Yosemite National Park

Managing human–bear (Ursus spp.) incidents is a top management priority in national parks inhabited by bears. Yosemite National Park (Yosemite), located in the Sierra Nevada in California, USA, receives up to 5 million visitors annually. It is also home to 300–500 black bears (U. americanus). Yosemite has an extensive history of black bear research, educational programs, and innovative solutions for reducing human–bear incidents. Despite this, human–bear incidents peaked in 1998 at 1,584. The resulting political fallout led to Yosemite receiving funds to expand its bear management program, including increasing its staffing and garbage pick-up, and improving the park’s bear-resistant infrastructure. In 2011, Yosemite reached a milestone when it recorded only 114 human–bear incidents—a 93% decrease from the 1998 high. To sustain this lower level of incidents while facing shrinking budgets and increasing visitation, bear managers turned to more modern technology. From 2014–2018, we evaluated the effectiveness of using global positioning system (GPS) collars to manage bears more proactively, increase staff and public engagement with bears, and gain insight into the bears’ spatial and temporal movements. The GPS collars were effective in achieving these goals, while also improving both our time management and our communication with park management. By the end of November 2018, Yosemite had recorded only 22 human–bear incidents—a 99% decrease from the 1998 high. The GPS collars are now an integral part of the Yosemite bear management program. We provide recommendations on how GPS technology may help other parks reduce human–bear incidents

Strategic and Interactive Writing Instruction: An efficacy study in grades 3-5

A quasi-experimental study was conducted to examine the impact of Strategic and Interactive Writing Instruction on 3rd-5th grade deaf and hard of hearing students’ writing and language compared to a business-as-usual condition (N=63). A total of 18 hours of instruction was provided for each of two types of writing—personal narrative (known as recount) and persuasive. Writing samples, collected prior to instruction and after, were scored for writing traits, language accuracy and complexity. Data were analyzed using a two-level, mixed-effects regression. Results show the treatment to be effective for recount and persuasive writing traits, and recount language variables, with effect sizes ranging from 0.46 to 2.01. Treatment effects were also substantial for persuasive writing language outcomes (0.38 to 1.06), although not all were statistically significant at the 0.05 level. The findings suggest the importance of apprenticeship in writing and consideration for the specific language needs of students with hearing loss