In many developing countries, those people who work the land as food producers are also the ones who most suffer from food insecurity. While many studies look at the power dynamics within the food system at the global level and the role played by transnational companies in particular, this investigation starts at the local level to look into the reasons behind the high levels of food insecurity among farmers. Specifically, it analyses how the relationship between the domestic food producers and the state in Tanzania has affected food security in rural areas, in particular in farmers' households. The question it asks is: How has the relationship between the state and farmers shaped food security in rural Tanzania since its independence? A qualitative approach has been employed: farmer interviews were conducted in 8 villages located in two regions of Tanzania - Coast and Kilimanjaro - and supplemented by interviews with state officials and civil society representatives. The villages surveyed in the Coast region suffer from arid conditions and are isolated from the main road that connects Dar es Salaam to Morogoro, while the villages studied in the Kilimanjaro region are on the slopes of the mountains around the town of Usangi, far from the touristic and commercial centres of Moshi and Arusha. Through interviews with farmers in these villages, the qualitative approach of this research offers a contextualised insight into food insecurity, the problems of the agricultural sector and farmers' attitude towards the state and its policies. The interviews with state officials and representatives of civil society were employed to investigate both current agricultural policies and officials’ attitude towards small scale farmers. This thesis makes an empirical contribution to the literature on food security and state-farmer relationships. I argue that the mixture of agricultural policies implemented by the state over the years have done little to improve the livelihoods of small scale farmers that live in isolated rural areas. One of the reasons why this is so is that the policies are not framed around the needs of small scale farmers (despite them being the great majority of the farmers in the country), and hence are not welcomed positively by the communities. The results of this study identify a reciprocal distrust between the state and farmers as one of the main causes of policy failure and unsatisfactory improvements in food security in rural areas. On one side, state officials see small scale farmers as inefficient and wish for the agricultural sector to be driven by medium and large scale farmers. On the other side, most farmers tend to dismiss state officials' advice as inadequate to the reality of farming. In general, farmers see the state as a distant entity, with which they have little contact and which they do not trust. I argue that the controversial relationship between the Tanzanian state and farmers is historically grounded and has a direct link with food insecurity amongst farmers for two main reasons. First, it affects the framing, objectives and implementation of agricultural policies, which thus fail to support small scale farmers. Second, it hinders the ability of farmers to successfully cooperate and/or create a coherent farmers' movement to improve food security and address their challenges at state level. Farmers' discontent is perceived in their alienation to politics, and in their distrust towards a state that has historically not been able to address their challenges nor improve their condition.

Degradation of terrestrial habitats with high conservation value has resulted in strategic efforts to cease or reverse their declines. Broad habitat management can restore ecological processes and large herbivores can provide ecological function in some terrestrial systems. Following years of decline and fragmentation, owing to factors such as cessation of traditional practices, lowland heathland has become an internationally important habitat with strategic protection. Free-ranging grazing aims to assist in mitigating such losses to habitat and vegetation communities, but quantifying the grazing regime and its associated impacts is necessary to ensure protection of these vulnerable systems. Reviews of herbivore impacts on lowland heath provide detailed evaluations and recognise the absence of experimental assessments and baseline monitoring. This research aimed to assess ecological activity and impacts (herbage removal, trampling and dunging) of horses and cattle on a lowland heath system to determine their influence on changing vegetation and to inform grazing management. This mixed regime is commonly adopted for restoration of semi-natural habitats but a failure to understand the separate vegetation impacts can be detrimental for the system as a whole. Behavioural activity was quantified using scan-sampling assessing spatial and temporal variation in behaviour, habitat selection and niche overlap, spatial occupancy and diet. A factorial design was set up to quantify the impacts of herbage removal, trampling and dunging to vegetation separately. Assessments vegetation community composition and architecture in treatment and control areas were undertaken. Analyses incorporated non-parametric and general linear models. Animals utilised their environments in different ways, varying for feeding and showed high habitat selectivity, based on physiology and foraging strategy primarily. Herbage removal strongly influenced vegetation architecture and heterogeneity owing to selection for graminoids and the plants’ competitive traits; effects on other plants were not as well defined due to minimal abundance. Trampling modified the vegetation structure due to reduced canopy density maintaining colonising gaps, but increased graminaceous cover and showed a capacity for lateral expansion. Dunging regime was highly influential for enhancing plant architecture and modified vegetation composition based on nutrient availability and competition. Worming regime was influential on architectural parameters and may be due to retarded dung degradation; further research is required. The findings contributed knowledge to lowland heath grazing management, validating the use of mixed regimes at low densities, for generating vegetation heterogeneity, for the control of dominating plants and for understanding the impacts of different animal-management practices. Expanding the reach of this research to comparable systems is necessary to develop the knowledge of grazing-management impacts. The work addressed an absence of experimental evaluation on these systems and also illustrated the importance of separately quantifying the impacts of large herbivores.

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The famous wealth of Norman Sicily was due to the careful managing of regal resources and property rights. The loose hand with which the Normans governed their economy allowed the island and its inhabitants to flourish, which in turn increased the wealth of the Norman kings.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / David G. Renter / Bradley J. White / The objective of my research was to quantify epidemiologic parameters associated with feedlot mortality and bovine respiratory disease complex (BRDC); the most significant cause of morbidity in U.S. feeder cattle. We conducted four retrospective studies utilizing individual health and cumulative cohort-level feedlot data. We developed a database that represented 33 U.S. feedlots from six states over ten years. Each project used a subset of these data. We found that the timing of BRDC was associated with important performance and health indices. In the first study, we evaluated the effect of the timing of individual BRDC treatments on standardized net returns. We found important performance and health measures (e.g. hot carcass weight and number treatments) driving net return differences associated with the timing of BRDC. For the second cohort-level study, we classified temporal patterns of BRDC, and evaluated associations among temporal patterns and performance and health. Temporal patterns were significantly associated with mean daily weight gain, days on feed, carcass weight, yield grade, quality grade, cumulative mortality, and retreatment risk. We also evaluated combined mortality and culling risks and quantified the effects of risk factors using count models. All risk factors (arrival weight, gender, and arrival month) were significant and the effects were modified by one another; effects of these covariate patterns have been impossible to quantify in smaller studies. Finally, we assessed the ability of regression models to predict cumulative BRDC morbidity based on arrival risk factors; then assessed the additional value of incorporating daily BRDC morbidity and mortality information. The percent of correctly classified cohorts did increase across days, but the effect of day was modified by weight, month, and feedlot. Information on daily morbidity was beneficial in predicting cumulative morbidity, but daily mortality provided little benefit. Our database containing animal health and cohort-level data allowed us to generate novel information on the effects of the timing of BRDC in feedlot populations. We also demonstrated effects of covariate patterns on adverse health outcomes that heretofore had been difficult to quantify. Finally, we showed that a predictive model for BRDC may be useful for the feedlot industry; this model should be further developed with future research.

Master of Agribusiness / Department of Agricultural Economics / Allen M. Featherstone / The cost of energy is a major concern for the United States and its citizens. With domestic demand at all time highs, the need for renewable fuels has become a key in reducing our countries reliance on imported energy. It is important for the U.S. to examine the feasibility of producing its own energy from renewable resources that can be grown domestically. Along with the potential financial gains from renewable fuels, the ability to control the supply of energy for the U.S. is also very important. With the amount of oil imported by the U.S., the ability to produce more of our nations needs and not be forced to rely on other countries could be important for our country moving forward. With the political unrest in many oil producing areas, the security of energy independence is a goal for the U.S. This study uses United States Department of Agriculture, Pro Exporter, Advance Trading, and other statistical sources to analyze the economic feasibility of an ethanol plant near Des Moines, IA. It looks at the available supply of corn in the area as well as the production of ethanol and distillers grains. An increase in the price of imported oil does not necessarily results in an economically viable ethanol plant. Many variables go into the economic viability of an ethanol plant and consumers will still buy the low cost good, and that may be imported energy. Some of these variables affecting economic viability include corn price and availability, denaturant price, natural gas price, ethanol demand and distillers grains demand. With the push for cleaner air and a cleaner environment, ethanol is also used as a gasoline additive to reduce emissions. As more states regulate a higher inclusion rate of ethanol, this will continue to create greater demand. A 100 million gallon ethanol plant is an economically viable investment in the Des Moines area, but when looking at the sensitivity tests, the better investment option if investors want to enter the ethanol industry, is to buy an existing ethanol plant.

Master of Science / Department of Grain Science and Industry / Praveen V. Vadlani / Synthesis of chemical derivatives from finite fossil fuels requires considerable energy inputs and leaves an undesirable environmental footprint. The emerging biorefinery approach leads to sustainable processing of biomass into a wide spectrum of bio-based products, catering to food, feed, chemicals, materials, and bioenergy industries. Cyanophycin (multi-L-arginyl-poly-L-aspartic acid, CGP) is a non-ribosomally synthesized reserve polypeptide, which consists of equimolar amounts of arginine and aspartic acid arranged as a polyaspartate backbone and arginine as the side chain. Cyanophycin is a source of the constituent N-functionalized platform chemical, which can be further processed into many other chemicals of importance. It can be hydrolyzed in mild condition to its constituent amino acids - aspartic acid and arginine. These amino acids may be utilized directly in food and pharmaceutical applications. Based on the chemical structure of these amino acids and the presence of functionalized nitrogen-containing groups, it is conceivable that a number of industrial chemicals can be synthesized, for example: 1, 4-butanediamine， a co-monomer in the production of nylon-4, 6. Other chemicals which could be obtained from cyanophcyin, that are currently prepared from fossil resources, include 1,4-butanediol and urea. Cyanophycin can also be hydrolyzed to a derivative with reduced arginine content or even to poly-aspartic acid, and used as a biodegradable substitute for synthetic polyacrylate in various technical process, such as water treatment (water softeners) and plastics. Cyanophycin is produced by most cyanobacteria in nature; however, these microbes are not suitable for large-scale production due to slow growth and low polymer content. Biosynthesis of cyanophycin is catalyzed by a single enzyme - cyanophycin synthetase (CphA), which is encoded by cyanophycin synthetase structure gene (cphA). The cphA gene can be expressed in several bacteria and plants. E.coli is one of the most commonly used bacterial hosts for the production of recombinant proteins. The recombinant culture has the ability to produce considerably large quantities of cyanophycin in a shorter period of time compared to cyanobacteria. Genome of Anabaena variabilis ATCC 29413 has been sequenced, and it contains the structural gene (cphA) for cyanophycin synthetase. The native enzyme-cyanophycin synthetase from this cyanbacterium culture had been purified and it consists of identical subunits of 98kDa. Polymerization of the amino acids to cyanophycin in vitro is dependent on the presence of ATP, K+, Mg2+, a (cyanophycin) primer and a thiol reagent such as β-mercaptoethanol in the reaction mixture. Our research is the first time that cphA gene from A. variabilis ATCC 29413 was cloned into E.coli. The 2.7 kb cphA gene was amplified by PCR, ligated to the vector pET45b+ and cloned into BL21 (DE3) pLysS and BL21 (DE3). Characterization of cyanophycin was performed by SDS-PAGE, HPLC, mass spectrometry and amino acid analysis. Results showed that protein with molecular weight of 21.5 to 31 kDa did not match any E.coli proteins when compared with E.coli protein data base, thereby showing expression of a protein foreign to host strain. Amino acids analyses showed that the cyanophycin produced by recombinant E.coli contained aspartic acid and arginine, and small amount of lysine, in the ratio: 1.05: 1: 0.2 (mass basis), thereby confirming cyanophycin biosynthesis. Experiments for high cyanophycin synthesis was performed at shake flask and 2-L fermentor level using recombinant BL21 (DE3) pLysS, LB broth as carbon and nutrient source, and casamino acids as primer. The maximum yield of cyanophycin obtained in flask level was 7.6% of cell dry mass, and the yield increased to 12.6% of cell dry mass at 2-L fermentor level. Cyanophycin is also referred to as “structural granules” because of substructures visible in electron micrographs. Phase contrast photomicrograph was able to depict cyanophycin inclusions in the cytoplasm, and transmission electron microscopy depicted finer details inside cell after IPTG induction.

Doctor of Philosophy / Department of Grain Science and Industry / Praveen V. Vadlani / Distillers Dried grain with Solubles (DDGS) is a co-product of grain-based ethanol and is primarily used as livestock feed. With increasing production of DDGS, it is imperative to produce value-added products and/or find new applications of DDGS to help sustain the biofuel industry. Carotenoids are expensive yet essential feed additives. Since animals cannot synthesize carotenoids and animal feeds including DDGS are generally poor in carotenoids, about 30-120 ppm of total carotenoids is added to animal feed to improve animal health. The objectives of this study were to 1) produce carotenoid (astaxanthin and β-carotene)-enriched DDGS by Phaffia rhodozyma and Sporobolomyces roseus monoculture and mixed culture submerged fermentation of whole stillage, 2) optimize fermentation media by response surface methodology (RSM) and mixture design followed by validation, 3) evaluate the nutritional profile of carotenoid-enriched DDGS, 4) improve carotenoid production by the use of precursors, and 5) develop carotenoid-enriched feeds namely, wheat bran, rice bran and soybean products. Carotenoid-enriched DDGS was produced from both monoculture and mixed culture fermentation with yields ranging from 17-233 µg/g. Upon media optimization, astaxanthin and β-carotene yields, especially in P. rhodozyma were enhanced by 177% and 164% to yield 98 and 275 µg/g respectively. Nutrition profiling of the carotenoid-enriched DDGS showed that the secondary fermentation resulted in low fiber, protein and %N and enhanced fat. Fiber was reduced by 77% and 66% by P. rhodozyma and S. roseus respectively, whereas the crude fat increased by 80% in mixed culture fermentation. Additionally, abundant vaccenic acid, a monounsaturated fatty acid was seen in S. roseus and mixed culture fermented DDGS. Vaccenic acid is a precursor of conjugated linolenic acid which is known to confer numerous health benefits. Fermentation of milo DDGS, wheat bran, rice bran and soybean products also resulted in carotenoid enrichment, with the best astaxanthin yield of 80 µg/g in rice bran, and best β-carotene yield of 837 µg/ g in soy flour. Precursors like mevalonic acid, apple pomace and tomato pomace increased carotenoid yield in DDGS and other substrates, with the yield increment depending on the substrate. Mevalonic acid resulted in the best astaxanthin and β-carotene yield increment by 140% and 236% resulting in 220 µg/g and 904 µg/g respectively in corn DDGS. Apple pomace and tomato pomace resulted in 29% carotenoid yield increment. Numerous studies thus far have used cheap agricultural substrates to produce carotenoids especially astaxanthin using P. rhodozyma with the intent of extracting the carotenoids for use in animal feed. However, by fermenting the animal feed directly, carotenoid-enriched feed can be produced without the need for extraction. By this simple yet novel carotenoid value addition, premium feeds or feed blends can be developed. Apart from carotenoid enrichment, low-fiber DDGS can help expand the market base of DDGS for use in non-ruminant feeds. Carotenoid value addition of DDGS can not only help sustain the biofuel industry but can also capture the aquaculture feed base which heavily relies on astaxanthin supplementation.