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Many policy and business decisions regarding food deserts in the U.S. are based on the United States Department of Agriculture (USDA) definition of a food desert. This definition only includes large/national chain grocery retailers, based on the assumption that these major retailers are the only affordable sources of food contributing to balanced diets. As alternative distribution channels, including smaller stores, start to include groceries in their product offering, the need to consider the role of other businesses in the food retailing environment should be addressed. This thesis assesses the role of smaller format grocery retailers (small local grocers, convenience stores, gas stations, dollar stores, and drug stores) in shaping the food desert landscape in Dallas, Texas. The analysis evaluates the products offered in these stores, and then identifies the difference these stores make when included in the USDA analysis. This was done by collecting in-store data to determine the variety of products offered, the affordability of those products, and the overall healthfulness of the store. In addition, the gaps in supply and demand were identified in the USDA-defined food deserts in order to identify the impact any smaller format retailer may have. The findings suggest that, overall, smaller format retailers do offer a variety of products needed for a balanced diet. However, the products in these stores are mostly not affordable, and most stores offer more unhealthy foods, than unhealthy. Overall, results suggest dollar stores may play a role in alleviating the impact of food deserts.

Limited access to, and availability of, fresh, healthy, and affordable food is a major concern in several communities across the United States of America. Such conditions have long perpetuated a wide variety of negative health outcomes that include, but are not limited to, obesity, diabetes, and other heart-related disease and illness, not to mention socio-economic immobility. Furthermore, the prevalence of limited food access and food insecurity is well researched and documented as an issue that disproportionately affects non-white, lower-income communities. The following research paper aims to better understand the characteristics of food deserts, the communities that are most affected by them, and the challenges that food deserts present to the local community. Additionally, the following research paper seeks to explain why most conventional grocery stores and supermarkets do not enter underserved markets. As such, it discusses the financial difficulties associated with grocery anchored retail developments in underserved markets, and examines why such communities struggle to attract investment in general. / 0 / SPK / specialcollections@tulane.edu

Master of Regional and Community Planning / Department of Landscape Architecture/Regional and Community Planning / Huston Gibson / Tens of millions of predominantly low-income, minority Americans live in food deserts – areas with poor access to healthful, affordable food. Food deserts have been associated with higher rates of diet-related diseases such as high blood pressure and obesity. These diseases carry significant morbidity and mortality and account for hundreds of billions of dollars in healthcare spending and lost productivity per year in the U.S. Establishment of a supermarket is the most effective intervention to eliminate a food desert. However, food deserts have historically been neglected by the retail industry. Local governments are rarely involved in supermarket recruitment. Often, food deserts themselves must recruit supermarkets. This study sought to understand how leadership and community engagement in supermarket recruitment influence its efficacy. The objective was to enable food deserts to more effectively recruit supermarkets. A case study of Argentine, a low-income, minority neighborhood in Kansas City, KS that successfully recruited a supermarket in 2013, was conducted. The heart of the case study was a series of interviews with individuals who were heavily involved in the recruitment. This study found the results of community engagement – specifically a community food assessment – were leveraged to attract funding and financing for a supermarket development. In settings where recruitment of a supermarket is contingent upon obtainment of these dollars, community engagement may be critical. Engagement empowers people to play an active role in shaping the future of their communities. It is a vital component of the urban planning process and government in general. Additionally, in the context of a food desert, engagement of residents can help accomplish the lofty goal of recruiting a supermarket and improving the food landscape – and health – of the community.

Background: Diabetes is one of the leading causes of death and disability among chronic diseases in the United States. Type 2 diabetes, which accounts for 90-95% of all diabetes cases, is a preventable form of disease which can be controlled through diet and physical activity. But residents of places such as ‘food deserts’, with no access to fresh food, often bear the burden of chronic diseases such as diabetes. There have been very few studies which have particularly looked at the association between food environment and diabetes prevalence in such deprived areas. Objective: The study investigated the association between living in food desert and developing diabetes or dying from the disease. It considered factors such as access to grocery stores and supermarkets, convenience stores, food joints and owning a personal vehicle that might affect diabetes related morbidity and mortality. It has also looked at factors such as income and race which might influence the association. Methodology: The study emphasizes on the lack of access to food, in low income and deprived neighborhoods and its impact on diabetes mortality and morbidity at the micro level of census tracts in Fulton County, Georgia. Diabetes related data was obtained from OASIS and Fulton County Department of Health and Wellness for the years 1994-2010 for 204 census tracts of Fulton County. Data for food desert distribution was extracted from the ‘Food desert Locator’ tool of the United States Department of Agriculture (USDA). Data on food stores was obtained through ReferenceUSA. Demographic information was acquired from American Fact Finder of the US Census Bureau. SPSS version 21 was used to calculate Pearson’s correlation to find the association between food environment and diabetes as well as to see whether there is an association between income and vehicle ownership with diabetes occurrence. ArcGIS 10.1 was used to represent data as maps showing the geographical distribution of various factors across the County and their association with the occurrence of diabetes. Results: Low income African American dominated census tracts which have been designated as food deserts have a higher occurrence of morbidity and mortality from diabetes. The correlation between number of supermarkets and grocery stores, convenience stores and full service restaurants has no statistically significant relation with diabetes. Similarly, there is no statistically significant relation between car ownership and diabetes. But the relationship between income and diabetes has a statistical significance. Conclusion: This study did not find any significant statistical association between diabetes and living in food desert. But from the GIS maps it can be observed that the number of food markets (supermarkets and grocery stores) is much less in the low income tracts than elsewhere and these are also the tracts which have higher occurrence of diabetes. Similarly, the numbers of convenience stores, which usually do not have a healthy collection of food, are more in the low income neighborhoods. The weak association between the factors studied might be because other factors such as education and access to healthcare have not been considered for this study. More research in this field is required to get a better picture of the diabetes health status in food desert areas.

The Four O'clock Family (Nyctaginaceae) has a number of genera with unusual morphological and ecological characters, several of which appear to have a "tendency" to evolve repeatedly in Nyctaginaceae. I present a molecular phylogeny for the Nyctaginaceae, consider taxonomic implications, biogeographic patterns, and the evolution of cleistogamy and gypsophily. These characters have each evolved multiple times in the xeric-adapted genera of the family. Further progress towards understanding these phenomena requires specific investigation of the ecology of pollination and gypsum tolerance. In the genus Boerhavia, an intensively sampled phylogeny based on internal transcribed spacer (ITS) and nitrate reductase (NIA) sequences provides new insights into relationships among species in the genus, and identifies a clade of annual species centered in the Sonoran Desert. Phylogeographic patterns are present in the genus that may reflect both relatively ancient vicariant events as well as the post-Pleistocene expansion of the Sonoran Desert. Many species in this group are found to be genetically cohesive, however two annual species complexes are found which species were nonmonophyletic. Since several mechanisms can potentially lead to the finding of nonmonophyletic species, Amplified Fragment Length Polymorphisms (AFLPs) were used to examine the structure of genetic variation in the two complexes. These data show that in these two groups, different evolutionary mechanisms are needed to explain the distribution of genetic diversity within and among populations. A complex comprised of Boerhavia spicata and B. xanti shows little evidence of genetic divergence between the species in Sonora, a pattern which may indicate recent contact between two very closely related forms. In contrast, high genetic structure between populations is found in the other complex, which contains the species with umbellate inflorescences. This complex includes several nominal species with highly restricted distributions, whose evolution may have been facilitated by low gene flow among populations. Little evidence was found for associations of inbreeding within populations, and floral traits which might be expected to influence outcrossing rates. / Dissertation

Compiled and Edited by Patricia Paylore / For 23rd International Geographical Congress, Moscow, 1976, Pre-Conference Meeting of the IGU Working Group on Desertification, Desert Research Institute, Ashkabad, Turkmen SSR, July 20-26, 1976.

The International Geographical Union Working Group on Desertification In and Around Arid Lands

All the warm deserts of the world exhibit gypsum crusts in favourable localities, generally areas with a source of gypsum and less than 250 mm of rainfall annually. The features, comprising loose powdery or cemented crystalline accumulations of calcium sulphate dihydrate, are found at the surface or within the uppermost 10 m of regolith. Thicknesses vary from a few millimetres to several metres and purities range from about 15% to nearly 100% gypsum. A review of the literature on gypsum soils and crusts reveals that the classification of types requires both standardizing and simplifying. A preliminary classification of crusts into three types can be made on the basis of structural and stratigraphic characteristics of examples from southern Tunisia and the Central Namib Desert. The types consist of subaerial aqueous evaporites, two subsurface and three surface forms. Detailed physical and chemical analyses justify a broadly similar genetic classification though one subsurface form is believed to be a primary pedogenic type of which the surface forms represent relics at various stages of solutional deterioration. Examples of subaerial aqueous evaporites are all products of shallow-water sedimentation in seasonally flooded chotts and sabkhas. The non-pedogenic subsurface type, croûte de nappe, is produced by displacive crystallization at the surface of a fluctuating water table. Gypsum precipitation results from either evaporation or mixing of saline waters causing saturation with respect to gypsum. Surface gypsum crusts are subsurface illuvial accretions exposed by erosion of overlying material. The gypsum is derived from solution of surface aeolian, atmospheric, colluvial or alluvial deposits by meteoric waters which percolate into the upper soil zone replenishing the antecedent soil moisture deficit. Subsurface accumulation results from displacive crystallization at host sediment grain contacts when gypsum saturated soil moisture evaporates.

Philosophiae Doctor - PhD / This thesis presents significant advances into the microbial ecology of hypolithic communities in two hyperarid deserts. Deserts account for one fifth of the Earths total surface area. These zones differ substantially in terms of climate, geomorphology, hydrology and vegetation. Desert biomes are, however, generally depauperate with particularly with respect to macroorganisms. Hypoliths, photosynthetic microbial assemblages associated with quartz rocks, are widely distributed in hot and cold desert environs where they may represent a large fraction of the standing biomass and mediate key ecosystem processes, including nutrient cycling. However, important questions regarding their (i) development (ii) community structure and assembly patterns and (iii) functional structure remain unaddressed. Here, molecular tools (T-RFLP, clone libraries and pyrosequencing) and multivariate data analyses were used to address these questions. This study presents evidence of species recruitment in the development of hypolithic communities in the Namib Desert. Hypolithic bacterial communities were compared at a fine scale (10 m radius). Multivariate analysis of T-RFLP-derived data showed that hypolithic and open soil communities were structurally distinct. Applying the ecological concept of ‘indicator species’, 6 and 9 indicator lineages were identified for hypoliths and soil, respectively. Hypolithic communities were dominated by cyanobacteria affiliated to Pleurocapsales, whereas actinobacteria were prevalent in the open soil. These results are consistent with the concept of species sorting and suggest that the underside of the quartz rocks provide conditions suitable for the development of discrete and demonstrably different microbial assemblages.However, strong evidence for neutral assembly processes was found, as almost 90% of the taxa present in the hypoliths were also detected in the open soil. All together, these results suggest that hypolithons do not develop independently from microbial communities found in the surrounding soil, but selectively recruit from local populations.The bacterial community structure and assembly patterns in hypolithons from Miers Valley (Antarctica) were investigated. Previous studies in this valley have identified three morphologically distinct hypolithic community types: cyanobacteria dominated(Type I), fungus dominated (Type II) and moss dominated (Type III). The bacterial composition of surface soils and hypolithic communities were shown to be clearly and robustly distinct, using T-RFLP analysis. Moreover, the bacterial assemblages were similar in Type II and Type III hypolithons and clearly distinct from those foundin Type I. Using16S ribosomal RNA gene (rRNA) 454 pyrosequencing,Proteobacteria were shown to be the most important bacterial component of all three types of hypolithic communities. As expected, Cyanobacteria dominated Type I hypolithons, whereas Actinobacteria dominated Types II and III hypolithons. Using a probabilistic dissimilarity metric and random sampling, deterministic processes were demonstrated to be relatively more important in shaping the structure of the bacterial community found in Type II and Type III hypolithons. Taken together, these results suggest that hypolithic development favors a sequential pathway with Type II hypolithons serving as an intermediate development state between Type I and Type In a more in depth analysis of the diversity patterns of key nutrient cycling genes in Antarctic Miers Valley edaphic communities, genes coding for carbon fixation (greenand red-like cbbL), nitrogen fixation (nifH), nitrification (amoA) and denitrification(nirK and nirS), were targeted. Multivariate analysis (PERMANOVA) showed that hypolithic and open soil communities were functionally distinct. Type I hypoliths were functionally more diverse than soils, suggesting higher potential for enzymatic activities. Taxonomic structure (derived from 16S rRNA data) showed congruence with functional traits (genes involved in C and N cycling). Redundancy analysis suggested that chemical variables (S, F, and NO3) were important structuring forces in the different communities. Taken together, the results suggest that stochastic processes such as dispersion cannot override the influence of environmental factors on functional diversity patterns.