Racial Disparities in Breast Cancer Survival: The Mediating Effects of Macro-Social Context and Social Network Factors

ABSTRACT This study attempts to clarify the associations between macro-social and social network factors and continuing racial disparities in breast cancer survival. The study improves on prior methodologies by using a neighborhood disadvantage measure that assesses both economic and social disadvantage and an ego-network measurement tool that assesses key social network characteristics. Our population-based sample included 786 breast cancer patients (nHWhite=388; nHBlack=398) diagnosed during 2005-2008 in Chicago, IL. The data included census-derived macro-social context, self-reported social network, self-reported demographic and medically abstracted health measures. Mortality data from the National Death Index (NDI) were used to determine 5-year survival. Based on our findings, neighborhood concentrated disadvantage was negatively associated with survival among nHBlack and nHWhite breast cancer patients. In unadjusted models, social network size, network density, practical support, and financial support were positively associated with 5-year survival. However, in adjusted models only practical support was associated with 5-year survival. Our findings suggest that the association between network size and breast cancer survival is sensitive to scaling of the network measure, which helps to explain inconsistencies in past findings. Social networks of nHWhites and nHBlacks differed in size, social support dimensions, network density, and geographic proximity. Among social factors, residence in disadvantaged neighborhoods and unmet practical support explained some of the racial disparity in survival. Differences in late stage diagnosis and comorbidities between nHWhites and nHBlacks also explained some of the racial disparity in survival. Our findings highlight the relevance of social factors, both macro and inter-personal in the racial disparity in breast cancer survival. Findings suggest that reduced survival of nHBlack women is in part due to low social network resources and residence in socially and economically deprived neighborhoods. Our findings indicate that, to improve survival among breast cancer patients, policies need to focus on continued improvement of access to care and reduction of racially patterned social and economic hardship. Additionally, our findings support the need for health care providers to assess social support resources of breast cancer patients at the time of diagnosis

Social Support Needs of Minority Breast Cancer Patients: Significance of Racial Homogeneity and Kin Composition of Social Networks

Social support from family and friends assists breast cancer patients navigate a life crisis, but more needs to be understood about specific social network characteristics that can benefit breast cancer patients. To address this need, the primary aim of this study was to identify social network factors that facilitate or reduce social support. Given racially patterned gaps in social support among breast cancer patients, a secondary goal was to identify network characteristics that are linked to gaps in support. We examined these research questions using data from a sample of 915 breast cancer patients (NHWhite=373; NHBlack=377; Hispanic=165) and 4,021 of their network members. To improve on prior research, we collected detailed social network data using a personal-network measurement tool and assessed needed and received support on five support components. Study findings identified specific network characteristics that facilitate these social support components. Network size was associated with increased practical, informational, emotional, and spiritual support. Network density was associated with increased practical support. Racial homogeneity in networks were associated with reduced informational support while a higher number of daughters in support networks was associated with increased emotional support. Compared to NHWhite patients, NHBlack patients were more likely to experience inadequate practical and financial support. Additionally, compared to NHWhite patients, Hispanic patients were more likely to experience inadequate informational and emotional support. The study found that network density, racial homogeneity, and gender composition of NHWhite, NHBlack and Hispanic social networks contributed to the racially patterned disparities in social support. Findings in this study could inform interventions aimed at increasing social support through greater mobilization of existing network ties as well as policy-driven, formal community building initiatives aimed at replicating benefits of naturally occurring networks

Emerging Longitudinal Trends in Health Indicators for Rural Residents Participating in a Diabetes and Cardiovascular Screening Program in Northern Alberta, Canada

Background. Geographic isolation, poverty, and loss of culture/tradition contribute to “epidemic” rates of diabetes amongst indigenous Canadians. The Mobile Diabetes Screening Initiative travels to rural indigenous and other remote communities in Alberta to screen for diabetes and cardiovascular risk. We sought to examine risk factors longitudinally. Methods. Clinical and anthropometric measurements were undertaken for 809 adults (aged 20–91) between November 2003 and December 2009. For those who had more than one MDSi visit, trend estimates (actual changes) were calculated for body mass index (BMI), weight, waist circumference, hemoglobin A1c (A1c), total cholesterol, and blood pressure. Results. Among those without diabetes (N = 629), BMI and weight increased (P < .01) and blood pressure decreased (P < .05). For those with diabetes (N = 180), significant improvements (P < .05) were observed for all indicators except waist circumference. Conclusion. Improvements observed suggest that MDSi's model may effectively mediate some barriers and support subjects in managing their health

Preliminary Results from an Experimental Assessment of a Natural Laminar Flow Design Method

A 5.2% scale semispan model of the new Common Research Model with Natural Laminar Flow (CRM-NLF) was tested in the National Transonic Facility (NTF) at the NASA Langley Research Center. The model was tested at transonic cruise flight conditions with Reynolds numbers based on mean aerodynamic chord ranging from 10 to 30 million. The goal of the test was to experimentally validate a new design method, referred to as Crossflow Attenuated NLF (CATNLF), which shapes airfoils to have pressure distributions that delay transition on wings with high sweep and Reynolds numbers. Additionally, the test aimed to characterize the NTF laminar flow testing capabilities, as well as establish best practices for laminar flow wind tunnel testing. Preliminary results regarding the first goal of validating the new design method are presented in this paper. Experimental data analyzed in this assessment include surface pressure data and transition images. The surface pressure data acquired during the test agree well with computational fluid dynamics (CFD) results. Transition images at a variety of Reynolds numbers and angles of attack are presented and compared to computational transition predictions. The experimental data are used to assess transition due to a turbulent attachment line, as well as crossflow and Tollmien-Schlichting modal instabilities. Preliminary results suggest the CATNLF design method is successful at delaying transition on wings with high sweep. Initial analysis of the transition front images showed transition Reynolds numbers that exceed historic experimental values at similar sweep angles. , section lif

Increasing forest loss worldwide from invasive pests requires new trade regulations

Loss of forests due to non-native invasive pests (including insects, nematodes, and pathogens) is a global phenomenon with profound population, community, ecosystem, and economic impacts. We review the magnitude of pest-associated forest loss worldwide and discuss the major ecological and evolutionary causes and consequences of these invasions. After compiling and analyzing a dataset of pest invasions from 21 countries, we show that the number of forest pest invasions recorded for a given country has a significant positive relationship with trade (as indicated by gross domestic product) and is not associated with the amount of forested land within that country. We recommend revisions to existing international protocols for preventing pest entry and proliferation, including prohibiting shipments of non-essential plants and plant products unless quarantined. Because invasions often originate from taxa that are scientifically described only after their introduction, current phytosanitary regulations – which target specific, already named organisms – are ineffective

Computational Investigation of a Boundary-Layer Ingesting Propulsion System for the Common Research Model

The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into a typical commercial aircraft using the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for CFD analysis. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2 deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.4% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from Boundary-Layer Ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry

Computational Investigation of a Boundary-Layer-Ingestion Propulsion System

The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for Computational Fluid Dynamics (CFD) analyses. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown, and improvements between subsequent BLI designs are presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet, with Reynolds number of 40 million based on mean aerodynamic chord and an angle of attack of 2 for all geometries. Results indicate an 8% reduction in engine power requirements at cruise for the BLI configuration compared to the baseline geometry. Small geometric alterations of the aft portion of the fuselage using CDISC has been shown to marginally increase the benefit from boundary-layer ingestion further, resulting in an 8.7% reduction in power requirements for cruise, as well as a drag reduction of approximately twelve counts over the baseline geometry