RESUMO
Introduction: In 2020, 13.8 million people in the United States struggled with food security. This means they were uncertain whether their food needs would be met. Where someone lives can influence struggles with food security. Food deserts are census tracts that experience high rates of poverty (20 percent of residents at/below poverty thresholds) and low access to grocery stores with nutritious foods. Food deserts and insecurity disproportionately affect disadvantaged communities and may contribute to health issues like diabetes, high blood pressure, and obesity. Public policies can be utilized to lessen the impact of food deserts and one way this can be achieved is through public transit. Methods: We characterized the role public transportation plays in connecting food desert residents with food by formulating network models from data on food deserts, grocery stores, and public transportation systems for five representative locations: Brown Deer, WI; Lawrence, KS; Albuquerque, NM; Charlotte, NC, and Raleigh, NC. We analyzed these networks by looking at centrality measures, specifically degree and closeness. These centrality measures provide insight on the situation regarding grocery store access for food deserts. Results: Results of the degree centrality measure varied across study sites; one site (Lawrence) had at least 1 bus stop within 0.25 miles (0.40 kilometers) of the representative address for each food desert. Conversely, two sites (Charlotte and Raleigh) each had 2 representative addresses with 0 bus stops within 0.75 miles (1.21 kilometers). When using the closeness centrality measure, 2 food deserts in Albuquerque had the highest number of grocery stores within 30 min (22 and 9) while 44% of food deserts in Raleigh had 0 grocery stores within 30 minutes. Conclusions: Using these results, we identify how public transportation could better connect people with food and offer suggestions to city leaders as a way to help eradicate food deserts.
RESUMO
BACKGROUND: Societies have always struggled with violence, but recently there has been a push to understand violence as a public health issue. This idea has unified professionals in medicine, epidemiological, and psychology with a goal to end violence and heal those exposed to it. Recently, analogies have been made between community-level infectious disease epidemiology and how violence spreads within a community. Experts in public health and medicine suggest an epidemiological framework could be used to study violence. METHODS: Building upon results from community organizations which implement public health-like techniques to stop violence spread, we look to formalize the analogies between violence and infectious diseases. Then expanding on these ideas and using mathematical epidemiological principals, we formulate a susceptible-exposed-infected model to capture violence spread. Further, we ran example numerical simulations to show how a mathematical model can provide insight on prevention strategies. RESULTS: The preliminary simulations show negative effects of violence exposure have a greater impact than positive effects of preventative measures. For example, our simulation shows that when the impact of violence exposure is reduced by half, the amount of violence in a community drastically decreases in the long-term; but to reach this same outcome through an increase in the amount of after exposure support, it must be approximately fivefold. Further, we note that our simulations qualitatively agree with empirical studies. CONCLUSIONS: Having a mathematical model can give insights on the effectiveness of different strategies for violence prevention. Based on our example simulations, the most effective use of community funding is investing in protective factors, instead of support after violence exposure, but of course these results do not stand in isolation and will need to be contextualized with the rest of the research in the field.