The Influence of Urban Form and Vegetation on Near-Source Dispersion in a Realistic Urban Canopy

The atmospheric boundary layer controls many interactions within the troposphere from larger scale atmospheric features to land-atmospheric interactions. The urban boundary layer is the layer above an urban area that is heavily impacted by what happens below, while the urban canopy layer is impacted by the immediate surroundings within the urban area. Understanding flow within the urban canopy layer is crucial for determining the distribution of particulate matter in urban areas and implications for air quality and human health. Previous experiments have examined downtown urban domains by releasing tracers to understand dispersion and dissipation of tracer plumes and how turbulence and urban geometry can affect them. Gaussian plume models have been used in the past to model dispersion in urban areas, especially for scalar transport. While multiple studies have been conducted to understand plume characteristics in urban environments, plume behavior close to point sources (< 1 km) and the effects of buildings and foliage on plume characteristics are not well understood. A field campaign, Tracer Release in an Urban Canopy (TRUC), was conducted in the Sunset Neighborhood of Vancouver, British Columbia in June 2017. This location is well-documented by previous field campaigns. The instrument configuration used during TRUC consisted of fifty spinning impaction traps, a mobile tower with 3-D sonic anemometers at two levels (16.6 m and 1.5 m), and five 2-D sonic anemometers deployed at 1.5 m. A mobile source at 2.4 m released 35 micron yellow/green and violet fluorescent microspheres from 3-D ultrasonic atomizer nozzles. Fourteen successful releases were conducted, each for twenty minutes, at four different locations throughout the neighborhood. An equation consisting of the Superposition of two Orthogonally-oriented Gaussian plume distributions (SOG; Miller et al., 2018) was utilized to fit the concentration data collected. The SOG was compared to the TRUC data to determine suitability for interpolating between collection points. While the SOG did characterize the pattern of the concentration behavior well for both the near and far fields, the magnitude of the concentrations was often misrepresented. Channeling of the plume was observed during the TRUC campaign, which was characterized by the SOG most of the time. Comparison of the mean wind angle relative to the street network and various plume parameters were utilized to visualize the channeling of the plume. Results from this data and usage of the SOG equation were utilized to determine higher-order plume moment statistics. Turbulence, building, and vegetation statistics were also calculated to describe the plume characteristics and behaviors. Evidence of a relationship was seen between the mean wind direction and first order moment, as well as between the mean wind angle and the second order plume moment. While turbulence does affect the plume, especially with mean wind direction, the urban geometry proved to affect the plume characteristics more so in the urban domain

An Evaluation of a Community Life Skills Program for Adolescents in Foster Care

Research indicates that adolescents who spent time in the foster care system are ill-prepared for independent living at the age of 18 and often experience negative outcomes due to this. The ability to live independently, after spending time in the foster care system, is partly dependent on one’s capacity to acquire and engage in adequate performance of various life skills. Some of these skills include budgeting, locating appropriate housing, and selecting higher education options, and should all be taught while still in foster care. The purpose of the present study was to evaluate the effectiveness of a life skills course provided by a community organization, StopGap Inc., by assessing skill acquisition of adolescents on various life skills. The participants included adolescents in the Kansas foster care system who are between the ages of 13 and 17. A pilot study was conducted using a natural comparison and control group design. Data were collected by direct observation, with pre-and post-assessment comparisons used to determine skill acquisition. The results revealed an increased acquisition of life skill across all participants, but no conclusion can be drawn from this data. Study one was conducted using a multiple baseline probe design across participants and skills to show better control of the intervention effects. This study extends the literature by assessing the use of behavioral approaches to improving performance of life skills among adolescents within the child welfare system

Prevalence and mapping of hepatitis C infections among men who have sex with men in New York City

Emerging sexually transmitted hepatitis C virus (HCV) epidemics among men who have sex with men (MSM) have been reported worldwide, with higher HCV infection rates among those who are HIV-infected. This study aims to determine prevalence of recent and chronic HCV infections among community-recruited MSM in New York City (NYC), map HCV infections by home, social, and sexual neighborhoods, and identify clusters of genetically linked HCV variants using phylogenetic analysis. The NYC M2M study recruited MSM via modified time-space, venue-based sampling and internet/mobile app-based recruitment during 2010–13. Participants completed a Google Earth map on neighborhoods of where they lived, socialized, and had sex in the last 3 months, an ACASI questionnaire, and a sexual network inventory about their sex partners. The men received HIV testing and provided serum samples. Testing on stored serum samples included HCV antibody and RNA viral load, HCV antibody avidity assay (avidity index 40 years, adjusted odds ratio (aOR) 3.56 (95% CI 1.57, 8.08), HIV-positive serostatus, aOR 3.18 (95% CI 1.40, 7.22), any sexually transmitted infection (STI) in the last 3 months, aOR 2.81 (95% CI 1.11, 7.13), and injection drug use (IDU) ever, aOR 4.34 (95% CI 1.69, 11.17). Mapping of HCV infections differed slightly by home, social, and sexual neighborhoods. Based on phylogenetic analysis from 12 HCV RNA-positive samples, no evidence of a clustered HCV epidemic was found. Overall HCV seroprevalence was 2.8% among community-recruited MSM in NYC, with higher prevalence among HIV-positive MSM compared to HIV-negative MSM. Only two participants were found to have recent HCV infection, with no evidence of a clustered HCV epidemic based on phylogenetic analysis. Our results support testing of HCV infection among HIV-negative MSM if they report having a recent STI and IDU in the past rather than universal HCV testing in all HIV-negative MSM

Prevalence and mapping of hepatitis C infections among men who have sex with men in New York City

Emerging sexually transmitted hepatitis C virus (HCV) epidemics among men who have sex with men (MSM) have been reported worldwide, with higher HCV infection rates among those who are HIV-infected. This study aims to determine prevalence of recent and chronic HCV infections among community-recruited MSM in New York City (NYC), map HCV infections by home, social, and sexual neighborhoods, and identify clusters of genetically linked HCV variants using phylogenetic analysis. The NYC M2M study recruited MSM via modified time-space, venue-based sampling and internet/mobile app-based recruitment during 2010–13. Participants completed a Google Earth map on neighborhoods of where they lived, socialized, and had sex in the last 3 months, an ACASI questionnaire, and a sexual network inventory about their sex partners. The men received HIV testing and provided serum samples. Testing on stored serum samples included HCV antibody and RNA viral load, HCV antibody avidity assay (avidity index 40 years, adjusted odds ratio (aOR) 3.56 (95% CI 1.57, 8.08), HIV-positive serostatus, aOR 3.18 (95% CI 1.40, 7.22), any sexually transmitted infection (STI) in the last 3 months, aOR 2.81 (95% CI 1.11, 7.13), and injection drug use (IDU) ever, aOR 4.34 (95% CI 1.69, 11.17). Mapping of HCV infections differed slightly by home, social, and sexual neighborhoods. Based on phylogenetic analysis from 12 HCV RNA-positive samples, no evidence of a clustered HCV epidemic was found. Overall HCV seroprevalence was 2.8% among community-recruited MSM in NYC, with higher prevalence among HIV-positive MSM compared to HIV-negative MSM. Only two participants were found to have recent HCV infection, with no evidence of a clustered HCV epidemic based on phylogenetic analysis. Our results support testing of HCV infection among HIV-negative MSM if they report having a recent STI and IDU in the past rather than universal HCV testing in all HIV-negative MSM

Distress Tolerance and Use of Antiretroviral Therapy Among HIV-Infected Individuals in Substance Abuse Treatment

Despite recent clinical guidelines recommending early initiation and widespread use of antiretroviral therapy (ART), many HIV-infected individuals are not receiving ART—in particular low-income, minority substance users. Few studies have examined psychological, as opposed to structural, factors related to not receiving ART in this population. Perceived capacity to tolerate physical and psychological distress, known as distress tolerance (DT), may be a particularly relevant yet understudied factor. The current study tested the relationship between self-reported physical and psychological DT and ART receipt among predominantly low-income, minority HIV-infected substance users (n=77). Psychiatric disorders, biological indicators of health status, ART use, structural barriers to health care, and self-reported physical and psychological DT were assessed. 61% of participants were receiving ART. The only factors that distinguished individuals not on ART were greater avoidance of physical discomfort, higher psychological DT, and higher CD4 count. Both DT measures remained associated with ART use after controlling for CD4 count and were associated with almost a two-fold decrease in likelihood of ART receipt. Current findings suggest higher perceived capacity to tolerate psychological distress and greater avoidance of physical discomfort are important factors associated with lower ART use among substance users and may be important intervention targets

Maps of HCV infections by neighborhoods.

<p>Maps of HCV infections by neighborhoods.</p

Phylogenetic analysis.

<p>Phylogenetic analysis.</p

HCV infection outcomes based on HIV status, N = 1,028.

<p>HCV infection outcomes based on HIV status, N = 1,028.</p

Sociodemographic and risk behavior characteristics, N = 1,028.

<p>Sociodemographic and risk behavior characteristics, N = 1,028.</p