2,684 research outputs found

    Host-feeding preferences and temperature shape the dynamics of West Nile virus: a mathematical model of assessing the abatement planning

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    West Nile virus (WNV) is prevalent in the United States but it shows considerable divergence in transmission patterns and spatio-temporal intensity.It is to be noted that the mechanism that drives the transmission potential of WNV is described by the abilities of host species to maintain and disseminate the pathogens pertinent with different eco-epidemiological factors that have an influence on the contact rates amongst the interacting species.There is growing evidence that several vectors exhibit strong feeding preferences towards different host communities.We construct a process based weather driven ordinary differential equation (ODE) model to understand the impact of one vector species Culex pipiens, preferred avian and non-preferred human hosts and compared it surveillance data for the Culex pipiens complex collected in Cook County, Illinois, USA.In our mechanistic model, we also demonstrate that adulticide treatments produced significant reductions in the Culex pipiens population.We take into account the feeding index that can be described as the ratio between observed frequency of mosquitoes feeding on one host compared to another host, divided by the expected frequency of mosquitoes feeding on these two hosts based on the presence of the particular hosts to develop this transmission model for WNV. Our findings demonstrate that the interplay between the feeding index and mosquito abatement strategy is rather a complex phenomenon and it induces a heterogeneous contact rates that should be included while modelling multi-host, multi-vector transmission model

    Reverse Engineering the Reproduction Number: A Framework for Data-Driven Counterfactual Analysis, Strategy Evaluation, and Feedback Control of Epidemics

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    During the COVID-19 pandemic, different countries, regions, and communities constructed various epidemic models to evaluate spreading behaviors and assist in making mitigation policies. Model uncertainties, introduced by complex transmission behaviors, contact-tracing networks, time-varying spreading parameters, and human factors, as well as insufficient data, have posed arduous challenges for model-based approaches. To address these challenges, we propose a novel framework for data-driven counterfactual analysis, strategy evaluation, and feedback control of epidemics, which leverages statistical information from epidemic testing data instead of constructing a specific model. Through reverse engineering the reproduction number by quantifying the impact of the intervention strategy, this framework tackles three primary problems: 1) How severe would an outbreak have been without the implemented intervention strategies? 2) What impact would varying the intervention strength have had on an outbreak? 3) How can we adjust the intervention intensity based on the current state of an outbreak? Specifically, we consider the epidemic intervention policies such as the testing-for-isolation strategy as an example, which was successfully implemented by the University of Illinois Urbana-Champaign (UIUC) and Purdue University (Purdue) during the COVID-19 pandemic. By leveraging data collected by UIUC and Purdue, we validate the effectiveness of the proposed data-driven framework

    Improving Participation Rates for Women of Color in Health Research: The Role of Group Cohesion

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s11121-011-0241-6.Adherence to physical activity and dietary interventions is a common challenge. Interventions that use group cohesion strategies show promise for increasing adherence, but have not been tested among women of color. The purpose of this study was to determine whether dimensions of group cohesion mediate the association between intervention condition and attendance within a community physical activity program for women of color. African American and Hispanic or Latina women (N=310) completed measurements at baseline and post-intervention and participated in a social cohesion intervention to improve physical activity and dietary habits. Women were assigned to a physical activity or fruit and vegetable intervention group. Social and task cohesion was measured using the Physical Activity Group Environment Questionnaire (PAGE-Q). Attendance was recorded at each of six intervention sessions. Women were generally middle-age (M age = 46.4 years, SD=9.1) and obese (M BMI = 34.4 kg/m2, SD=7.7). The estimate of the mediated effect was significant for all group cohesion constructs, indicating both task constructs—attraction to the group’s task (SE=0.096, CI: −0.599 to −0.221) and group integration around the task (SE=0.060, CI: −0.092 to −0.328)—and social constructs—attraction to the group’s social aspects (SE=0.046, CI: −0.546 to −0.366) and group integration around social aspects (SE=0.046, CI: −0.546 to −0.366)—significantly mediated the association between group assignment and attendance. Both task and social constructs are important to improve attendance in health promotion interventions for women of color

    The Physical Activity Resource Assessment (PARA) instrument: Evaluating features, amenities and incivilities of physical activity resources in urban neighborhoods

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    Background: Neighborhood environment factors may influence physical activity (PA). The purpose of this study was to develop and test a brief instrument to systematically document and describe the type, features, amenities, quality and incivilities of a variety of PA resources. Method: The one-page Physical Activity Resource Assessment (PARA) instrument was developed to assess all publicly available PA resources in thirteen urban lower income, high ethnic minority concentration neighborhoods that surrounded public housing developments (HDs) and four higher income, low ethnic minority concentration comparison neighborhoods. Neighborhoods had similar population density and connectivity. Trained field coders rated 97 PA resources (including parks, churches, schools, sports facilities, fitness centers, community centers, and trails) on location, type, cost, features, amenities, quality and incivilities. Assessments typically took about 10 minutes to complete. Results: HD neighborhoods had a mean of 4.9 PA resources (n = 73) with considerable variability in the type of resources available for each neighborhood. Comparison neighborhoods had a mean of 6 resources (n = 24). Most resources were accessible at no cost (82%). Resources in both types of neighborhoods typically had about 2 to 3 PA features and amenities, and the quality was usually mediocre to good in both types of neighborhoods. Incivilities at PA resources in HD neighborhoods were significantly more common than in comparison neighborhoods. Conclusion: Although PA resources were similar in number, features and amenities, the overall appearance of the resources in HD neighborhoods was much worse as indicated by substantially worse incivilities ratings in HD neighborhoods. The more comprehensive assessment, including features, amenities and incivilities, provided by the PARA may be important to distinguish between PA resources in lower and higher deprivation areas

    The Physical Activity Resource Assessment (PARA) instrument: Evaluating features, amenities and incivilities of physical activity resources in urban neighborhoods

    Get PDF
    BACKGROUND: Neighborhood environment factors may influence physical activity (PA). The purpose of this study was to develop and test a brief instrument to systematically document and describe the type, features, amenities, quality and incivilities of a variety of PA resources. METHOD: The one-page Physical Activity Resource Assessment (PARA) instrument was developed to assess all publicly available PA resources in thirteen urban lower income, high ethnic minority concentration neighborhoods that surrounded public housing developments (HDs) and four higher income, low ethnic minority concentration comparison neighborhoods. Neighborhoods had similar population density and connectivity. Trained field coders rated 97 PA resources (including parks, churches, schools, sports facilities, fitness centers, community centers, and trails) on location, type, cost, features, amenities, quality and incivilities. Assessments typically took about 10 minutes to complete. RESULTS: HD neighborhoods had a mean of 4.9 PA resources (n = 73) with considerable variability in the type of resources available for each neighborhood. Comparison neighborhoods had a mean of 6 resources (n = 24). Most resources were accessible at no cost (82%). Resources in both types of neighborhoods typically had about 2 to 3 PA features and amenities, and the quality was usually mediocre to good in both types of neighborhoods. Incivilities at PA resources in HD neighborhoods were significantly more common than in comparison neighborhoods. CONCLUSION: Although PA resources were similar in number, features and amenities, the overall appearance of the resources in HD neighborhoods was much worse as indicated by substantially worse incivilities ratings in HD neighborhoods. The more comprehensive assessment, including features, amenities and incivilities, provided by the PARA may be important to distinguish between PA resources in lower and higher deprivation areas

    PbTi1-xPdxO3: A New Room-temperature Magnetoelectric Multiferroic Device Material

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    There have been a large number of papers on bismuth ferrite (BiFeO3) over the past few years, trying to exploit its room-temperature magnetoelectric multiferroic properties. Although these are attractive, BiFeO3 is not the ideal multiferroic, due to weak magnetization and the difficulty in limiting leakage currents. Thus there is an ongoing search for alternatives, including such materials as gallium ferrite (GaFeO3). In the present work we report a comprehensive study of the perovskite PbTi1-xPdxO3 with 0 < x < 0.3. Our study includes dielectric, impedance and magnetization measurements, conductivity analysis and study of crystallographic phases present in the samples with special attention paid to minor phases, identified as PdO, PbPdO2, and Pd3Pb. The work is remarkable in two ways: Pd is difficult to substitute into ABO3 perovskite oxides (where it might be useful for catalysis), and Pd is magnetic under only unusual conditions (under strain or internal electric fields). The new material, as a PZT derivative, is expected to have much stronger piezoelectric properties than BiFeO3

    Overexpression of specific CD44 isoforms is associated with aggressive cell features in acquired endocrine resistance

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    While endocrine therapy is the mainstay of ER+ breast cancer, the clinical effectiveness of these agents is limited by the phenomenon of acquired resistance that is associated with disease relapse and poor prognosis. Our previous studies revealed that acquired resistance is accompanied by a gain in cellular invasion and migration and also that CD44 family proteins are overexpressed in the resistant phenotype. Given the association of CD44 with tumor progression, we hypothesized that its overexpression may act to promote the aggressive behavior of endocrine-resistant breast cancers. Here, we have investigated further the role of two specific CD44 isoforms, CD44v3 and CD44v6, in the endocrine-resistant phenotype. Our data revealed that overexpression of CD44v6, but not CD44v3, in endocrine-sensitive MCF-7 cells resulted in a gain in EGFR signaling, enhanced their endogenous invasive capacity, and attenuated their response to endocrine treatment. Suppression of CD44v6 in endocrine-resistant cell models was associated with a reduction in their invasive capacity. Our data suggest that upregulation of CD44v6 in acquired resistant breast cancer may contribute to a gain in the aggressive phenotype of these cells and loss of endocrine response through transactivation of the EGFR pathway. Future therapeutic targeting of CD44v6 may prove to be an effective strategy alongside EGFR-targeted agents in delaying/preventing acquired resistance in breast cancer
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