The effects of racially-motivated emotional arousal on the eating behaviors of african american women

Disparities between African Americans and Caucasians remain vast across a wide variety of health indicators. Chronic stress has been identified as a risk factor for a variety of chronic illnesses and poor health outcomes. One type of chronic stress that has been linked to health disparities is the stress associated with experiences of racial discrimination. The stress African Americans encounter as a result of their racist experiences contributes to a chronic elevation of their physiological stress response. In addition to stress, a major risk factor for coronary heart disease and diabetes is obesity, which has been established as a major health problem in the United States. Obesity in African American women tends to be the result of psychosocial, behavioral, cultural, and environmental factors, among others. The purpose of this dissertation was to investigate possible psychosocial contributions of racism-related stress and the eating behaviors of African American women to their high rates of obesity. Thus, this study was designed to link survey research demonstrating racial discrimination as a stressor with negative effects on health behaviors and outcomes in African Americans with laboratory studies demonstrating how stress produces binge eating among individuals who typically try to restrain their eating. A number of hypotheses guided this two-part study, which followed a 2 (Eating Style: Restrained vs. Unrestrained Eating) x 2 (Ostracism: Inclusion vs. Exclusion) x 2 (Reference Group: Outgroup vs. Ingroup) design. Three hundred nineteen women participated in Study 1 where they completed questionnaires on their eating behaviors and racist experiences, and 124 of those women participated in the lab portion, Study 2, where they ate snacks as they engaged in an online social interaction with 3 other participants. Results indicate that although the in-lab manipulated experience of discrimination had numerous detrimental effects on psychological well-being, it did not influence the amount of food participants ate in the laboratory. Although many of the hypotheses were not supported, this study may provide procedural precedence for future restrained or emotional eating, racial microaggressions, or social ostracism studies. Results from this study also suggest several useful implications for obesity treatment and prevention programs

Spatial Analysis of Bifenthrin Sediment and Water Concentrations in California Waterbodies from 2001 to 2017

The objective of this study was to summarize and map bifenthrin sediment and water column monitoring data from California waterbodies (2001–2017) and determine where detected bifenthrin concentrations were reported and potential toxicity to aquatic biota may exist. Bifenthrin sediment data based on targeted sampling in depositional areas were available for more sites (982) than water column data (716 sites), and sediment sites had a lower percent of nondetected concentrations (36%) when compared with water values (77%). Comparison of results from three ambient sediment toxicity tests from sediment sites and six ambient toxicity tests from water sites showed no toxicity from 43% of the sediment sites and 65% of the water sites. A comparison of sediment measurements with acute toxicity data from two test species (Hyalella azteca and Chironomus tentans) showed no toxicity at 80–99.5% of the sites. Bifenthrin total water concentrations compared with a proposed 2015 chronic criterion of 0.01 ng/L showed no exceedances at 77% of the sites. Due to the conservative assumptions used in this analysis, bifenthrin ecological risk to aquatic life in California water bodies from both sediment exposure based on only targeted sampling from depositional areas and water column exposures based on using only total concentrations (not the bioavailable phase) is generally judged to be low statewide

Optimal and Random Partitions of Random Graphs

The behavior of random graphs with respect to graph partitioning is considered. Conditions are identified under which random graphs cannot be partitioned well, i.e., a random partition is likely to be almost as good as an optimal partition

Development of New Heuristics for the Euclidean Traveling SalesmanProblem

Many heuristics have been developed to approximate optimal tours for the Euclidean Traveling Salesman Problem (ETSP). While much progress has been made, there are few quick heuristics which consistently produce tours within 4 percent of the optimal solution. This project examines a few of the well known heuristics and introduces two improvements, Maxdiff and Checks. Most algorithms, during tour constrution, add a city to the subtour because the city best satisfies some criterion. Maxdiff, applied to an algorithm, ranks a city according to its effect (based on the algorithm's criterion) if it is not added to the subtour

An Analysis of Multiple Stressors on Resident Benthic Communities in a California Agricultural Stream

This 3-year study (2015-2017) was designed to characterize benthic communities (macroinvertebrates) and physical habitat in an agriculturally dominated waterbody in the Central Coast area of California (Santa Maria River). Benthic communities as represented by various metrics that represent richness, composition, tolerance/intolerance and trophic measures were used as response variables for the various stressors described below. Concurrent water quality evaluations, physical sediment parameters (grain size and total organic carbon [TOC]), pyrethroids, bulk metals—including simultaneously extracted metals (SEM) and acid volatile sulfides (AVS) ratios—and nutrients were measured. The relationship of various benthic metrics to physical habitat metrics, pyrethroids, metals, nutrients and sediment characteristics was evaluated for the 3-year data set. Total physical habitat scores in this watershed were considered to be poor. Samples collected for various sediment chemistry measurements were from depositional areas (fine grain areas primarily silt and clay) where hydrophobic chemicals such as pyrethroids could be found if sources exist. Dominant benthic taxa collected were generally considered to be tolerant to moderately tolerant of environmental stressors and rated as impaired based on a benthic index. Potentially toxic sediment concentrations of arsenic, cadmium and nickel were reported at various sites based on a comparison with existing threshold effect levels. Pyrethroid concentrations interpreted by using a highly protective toxics units approach with a laboratory sensitive taxon (Hyalella) suggested potential toxicity at various sites. Nutrient concentrations could not be interpreted within the context of potential impairment because the State of California has not developed nutrient criteria. The results of the stepwise linear regression models comparing benthic metrics with all environmental variables showed that TOC was the most important variable shaping the benthic communities. In contrast, pyrethroids, metals and physical habitat were not shown to be significant factors shaping benthic communities. The summary multivariate canonical correlation analysis indicated that less stressed, more diverse benthic communities tended to be associated more with TOC-rich finer sediments and lower concentrations of phosphorous-based nutrients, and more stressed, less diverse benthic communities tended to be associated with less organically rich, somewhat less fine sediments and higher phosphorous concentrations

Local Search for the Retrieval Layout Problem

An information graph is a data representation for object-oriented databases in which each object is a vertex and each relationship between objects is an edge. The retrieval layout problem is to arrange the storage of an information graph on a physical medium so as to use storage efficiently and to allow rapid navigation along paths in the graph. This paper describes an empirical study of the performance of various local search heuristics for the retrieval layout problem, including local optimization, simulated annealing, tabu search, and genetic algorithms. In addition, the hierarchical hybrid approach is introduced

Heuristics for Laying Out Information Graphs

The concept of an information graph is introduced as a representation for object-oriented databases. The retrieval layout problem is an optimization problem defined over the class of information graphs. The layout abstracts the space efficiency of representing the database as well as the time efficiency of information retrieval. Heuristics for the retrieval layout problem are identified and evaluated experimentally. A new heuristic, connectivity traversal, is found to be fast and to produce high quality layouts

Representing Polyhedra: Faces are Better than Vertices

In this paper, we investigate the reconstruction of planar-faced polyhedra given their spherical dual representation. We prove that the spherical dual representation is unambiguous for all genus 0 polyhedra and that a genus 0 polyhedra can be uniquely reconstructed in polynomial time. We also prove that when the degree of the spherical dual representation is at most four, the representation is unambiguous for polyhedra at any genus. The first result extends the well known result that a vertex or face connectivity graph represents a polyhedron unambiguously when the graph is triconnected and planar in the case of planar-faced polyhedra. The second result shows that when each face of a polyhedron of arbitrary genus has at most four edges, the polyhedron can be recontructed uniquely. This extends the result that a polyhedron can be uniquely reconstructed when each face of the polyhedron is triangular. To obtain this result, we prove that the 4-dimension hypercube, a classic example of ambiguity in the wire frame representation scheme, is unambiguous when the same connectivity graph is viewed as the spherical dual representation of a polyhedron and thus that faces are a better representation than vertices. A result of the reconstruction algorithm is that high level features of the polyhedron are naturally extracted. Both of our results explicitly use the fact that the faces of the polyhedron are planar. We conjecture that the spherical dual representation is unambiguous for polyhedra of any genus

Representing Polyhedra: Faces Are Better than Vertices

In this paper, we investigate the reconstruction of planar-faced polyhedra given their spherical dual representation. We prove that the spherical dual representation is unambiguous for all genus 0 polyhedra and that a genus 0 polyhedron can be uniquely reconstructed in polynomial time. We also prove that when the degree of spherical dual representation is at most four, the representation is unambiguous for polyhedra of any genus