Adolescent Self-Consent for Biomedical HIV Prevention Research: Implications for Institutional Review Board Approval and Implementation

Purpose The Adolescent Medicine Trials Network Protocol 113 (ATN113) is an open-label, multisite demonstration project and Phase II safety study of human immunodeficiency virus (HIV) preexposure prophylaxis with 15- to 17-year-old young men who have sex with men that requires adolescent consent for participation. The purpose of this study was to examine factors related to the process by which Institutional Review Boards (IRBs) and researchers made decisions regarding whether to approve and implement ATN113 so as to inform future biomedical HIV prevention research with high-risk adolescent populations. Methods Participants included 17 researchers at 13 sites in 12 states considering ATN113 implementation. Qualitative descriptive methods were used. Data sources included interviews and documents generated during the initiation process. Results A common process for initiating ATN113 emerged, and informants described how they identified and addressed practical, ethical, and legal challenges that arose. Informants described the process as responding to the protocol, preparing for IRB submission, abstaining from or proceeding with submission, responding to IRB concerns, and reacting to the outcomes. A complex array of factors impacting approval and implementation were identified, and ATN113 was ultimately implemented in seven of 13 sites. Informants also reflected on lessons learned that may help inform future biomedical HIV prevention research with high-risk adolescent populations. Conclusions The results illustrate factors for consideration in determining whether to implement such trials, demonstrate that such protocols have the potential to be approved, and highlight a need for clearer standards regarding biomedical HIV prevention research with high-risk adolescent populations

Speaking vocabulary of first grade children

Thesis (Ed.M.)--Boston Universit

Evaluation of Rhenium Joining Methods

Coupons of rhenium-to-Cl03 flat plate joints, formed by explosive and diffusion bonding, were evaluated in a series of shear tests. Shear testing was conducted on as-received, thermally-cycled (100 cycles, from 21 to 1100 C), and thermally-aged (3 and 6 hrs at 1100 C) joint coupons. Shear tests were also conducted on joint coupons with rhenium and/or Cl03 electron beam welded tabs to simulate the joint's incorporation into a structure. Ultimate shear strength was used as a figure of merit to assess the effects of the thermal treatment and the electron beam welding of tabs on the joint coupons. All of the coupons survived thermal testing intact and without any visible degradation. Two different lots of as-received, explosively-bonded joint coupons had ultimate shear strengths of 281 and 310 MPa and 162 and 223 MPa, respectively. As-received, diffusion-bonded coupons had ultimate shear strengths of 199 and 348 MPa. For the most part, the thermally-treated and rhenium weld tab coupons had shear strengths slightly reduced or within the range of the as-received values. Coupons with Cl03 weld tabs experienced a significant reduction in shear strength. The degradation of strength appeared to be the result of a poor heat sink provided during the electron beam welding. The Cl03 base material could not dissipate heat as effectively as rhenium, leading to the formation of a brittle rhenium-niobium intermetallic

Network Centrality of Metro Systems

Whilst being hailed as the remedy to the world’s ills, cities will need to adapt in the 21st century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no “winner takes all”) unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities

The association of urinary incontinence and disability among a diverse sample of midlife Study of Women’s Health Across the Nation women

ObjectiveThe aim of the study is to examine whether urinary incontinence (UI) type, frequency, and amount are associated with self-reported disability in a racially/ethnically diverse cohort of community-dwelling midlife women.MethodsData were from longitudinal analyses of questionnaires from the multicenter, prospective cohort Study of Women's Health Across the Nation (SWAN). We used multivariable ordinal logistic regression to examine whether urinary incontinence type, frequency, and amount at the 13th follow-up were associated with the World Health Organization Disability Assessment Schedule at the 15th follow-up controlling for other factors (menopause status, body mass index, lifestyle and psychosocial factors, and disability at follow-up 13).ResultsUrinary incontinence was associated with subsequent reports of disability in participants, particularly in the World Health Organization Disability Assessment Schedule domains of mobility ( P < 0.0001), communication ( P = 0.0057), and life activities ( P = 0.0407). Associations were strongest for mixed UI type compared with stress UI or urgency UI (odds ratio [OR] = 1.66, 95% confidence interval [CI] = 1.26-2.17, P < 0.001), daily frequency of UI compared with monthly or less than weekly frequency of UI (OR = 1.61, 95% CI = 1.04-2.47, P < 0.001), and larger amounts of urine leakage compared with drops of leakage (OR = 2.98, 95% CI = 1.58-5.62, P < 0.0001) for mobility/getting around domain.ConclusionsUrinary incontinence seems to have a strong association with multiple domains of disability, including mobility and interacting with others, after approximately 3.7 years. Thus, UI may be an important factor limiting social engagement among women. Screening for mixed UI and UI that occurs greater than weekly and in amounts requiring pads may yield better information regarding an individual's future disability risk and may preserve social interaction

A Laboratory Model of a Hydrogen/Oxygen Engine for Combustion and Nozzle Studies

A small laboratory diagnostic thruster was developed to augment present low thrust chemical rocket optical and heat flux diagnostics at the NASA Lewis Research Center. The objective of this work was to evaluate approaches for the use of temperature and pressure sensors for the investigation of low thrust rocket flow fields. The nominal engine thrust was 110 N. Tests were performed at chamber pressures of about 255 kPa, 370 kPa, and 500 kPa with oxidizer to fuel mixture ratios between 4.0 and 8.0. Two gaseous hydrogen/gaseous oxygen injector designs were tested with 60 percent and 75 percent fuel film cooling. The thruster and instrumentation designs were proven to be effective via hot fire testing. The thruster diagnostics provided inner wall temperature and static pressure measurements which were compared to the thruster global performance data. For several operating conditions, the performance data exhibited unexpected trends which were correlated with changes in the axial wall temperature distribution. Azimuthal temperature distributions were found to be a function of operating conditions and hardware configuration. The static pressure profiles showed that no severe pressure gradients were present in the rocket. The results indicated that small differences in injector design can result in dramatically different thruster performance and wall temperature behavior, but that these injector effects may be overshadowed by operating at a high fuel film cooling rate