skip to main content


Title: A study of chaos and its control in a harvested tri-trophic food chain model with alternative food source and diffusion effect
Award ID(s):
1839993
NSF-PAR ID:
10183602
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Nonlinear studies
Volume:
27
Issue:
2
ISSN:
1359-8678
Page Range / eLocation ID:
505-528
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    North Carolina is labeled as the 10th hungriest state in America, with almost 1 in 5 children in North Carolina facing hunger regularly. Based on these numbers alone, childhood hunger is an important issue that needs to be addressed. This paper focuses on the thirty-four counties serviced by the Food Bank of Central and Eastern North Carolina. Each county is mapped out, showing the percentage of children receiving free or reduced meals. These numbers are then compared to the number of Weekend Power Packs, Kid Cafes, and School Pantry locations per county. This project illustrates the strength of visual analytics for decision making 
    more » « less
  2. Abstract

    The second UN Sustainable Development Goal establishes food security as a priority for governments, multilateral organizations, and NGOs. These institutions track national-level food security performance with an array of metrics and weigh intervention options considering the leverage of many possible drivers. We studied the relationships between several candidate drivers and two response variables based on prominent measures of national food security: the 2019 Global Food Security Index (GFSI) and the Food Insecurity Experience Scale’s (FIES) estimate of the percentage of a nation’s population experiencing food security or mild food insecurity (FI). We compared the contributions of explanatory variables in regressions predicting both response variables, and we further tested the stability of our results to changes in explanatory variable selection and in the countries included in regression model training and testing. At the cross-national level, the quantity and quality of a nation’s agricultural land were not predictive of either food security metric. We found mixed evidence that per-capita cereal production, per-hectare cereal yield, an aggregate governance metric, logistics performance, and extent of paid employment work were predictive of national food security. Household spending as measured by per-capita final consumption expenditure (HFCE) was consistently the strongest driver among those studied, alone explaining a median of 92% and 70% of variation (based on out-of-sample R2) in GFSI and FI, respectively. The relative strength of HFCE as a predictor was observed for both response variables and was independent of the countries used for model training, the transformations applied to the explanatory variables prior to model training, and the variable selection technique used to specify multivariate regressions. The results of this cross-national analysis reinforce previous research supportive of a causal mechanism where, in the absence of exceptional local factors, an increase in income drives increase in food security. However, the strength of this effect varies depending on the countries included in regression model fitting. We demonstrate that using multiple response metrics, repeated random sampling of input data, and iterative variable selection facilitates a convergence of evidence approach to analyzing food security drivers.

     
    more » « less
  3. Abstract

    This research explores the dependencies between community food security and local food movements. We use a mixed methods approach that includes: analysis of 2.97 million pounds of food bank donations from 296 organizations, network analysis of the local food system with 77 farms and 439 market connections, and 24 interviews with food bank donors and staff. We find strong ties between the food bank and local food producers, particularly producers that are organic and sell directly to the public. Nearly half the donating farms also sold to local markets; and together supplied the majority of locally produced food (296,090 pounds) distributed by the food bank. Yet, both movements operate within capitalist systems, even when the food is decommodified. Producer motivations for donating are not purely based on social responsibility to feed the hungry but also acknowledge the financial and marketing benefits of donating in terms of receiving tax credits, participating in procurement programs, and improving public relations. Our findings suggest that research and policy focused on local food systems or food security should consider such ties and their implications for growing or maintaining resulting practices.

     
    more » « less