Biomass gasification is generally regarded as a promising technology for various advanced application in energy production. Biomass is the only carbon-based sustainable option among the renewable energy sources. This study is focused on fostering biomass gasification for electricity generation sector in India. The study addresses four broad aspects of biomass gasification for electricity generation - feedstock properties and gasification technology, policy and regulatory framework governing the sector, financial evaluation of electricity generation from biomass gasification, and feedstock supply. The study is divided in four chapters, each of which addresses one aspect of electricity generation through biomass gasification. Based on literature, first chapter presents a brief review of various properties of biomass feedstocks that are critical for gasification. It reviews the thermochemical conversion processes and the major issues related with biomass gasification with reference to some promising gasifier technology systems. Based on literature, second chapter examines the importance of national and sub-national policies supporting the development of bioenergy industry (including gasification for electricity generation) in various countries. The policies and instruments deployed globally are compared with those deployed in India. Third chapter posits a framework for conducting financial evaluation of a gasification power project. A case study of pine needle gasification power project in a remote rural area of Northern India is considered. In absence of historical data related with similar projects, a probability distribution for the Net Present Value (NPV) for the project is generated with the help of Monte Carlo Simulation. The simulation for NPV uses estimates of input variables from the data gathered from an existing pine needle based gasifier operating in the study area. Continuing with the case study, fourth chapter studies the villagers perspective on supplying pine needles to the gasification project. . A survey was administered to estimate villagers willingness to collect pine needles from the forests and supply it at a price to the gasification project. The willingness is modeled on demographic, livelihood, and latent factors, that are used in a Multinomial Logistic Regression Model to estimate the probability of households willingness to collect and supply pine needles to the project.

Methane has a warming potential 28 times that of carbon dioxide and has been increasing in the Earths atmosphere since 1750. An understanding of the dynamics of methane emissions from natural sources is becoming increasingly important as we may need to mitigate emissions from these sources in the future to help reduce the effects of climate change. Wetlands are the single largest natural source of methane; however, little attention has been given to how plant species, biota, and interactions between above and belowground communities and microbial communities may affect methane emissions. First, microbial community structure and function was assessed for two salt marsh plant species, Spartina alterniflora and Juncus romerianus via bacterial, archaeal, and fungal gene fragments, and extracellular enzyme assays to determine whether wetland microbial communities were structured by vegetation, and whether communities were functionally different. Bacterial communities were differentiated by plant species in two of three sites, suggesting while vegetation likely plays a role in structuring these communities, specific site characteristics are likely of equal importance. Fungal communities were influenced more by site than vegetation, and archaeal communities appeared to be structured by vegetation. Second, four freshwater wetland plants (Sagittaria lancifolia, Panicum hemitomon, Eleocharis macrostachya, Echinochloa walteri) were transplanted and grown in large mesocosms, and clipped to differing heights under different nutrient treatments to detect changes in methane emissions, methanogen, and methanotroph communities. Methane emission rates were plant species specific, and a three way interaction indicated that species, nutrient level, and clipping level altered methane emission. Methanogen and methanotroph communities were not altered by the treatments. Lastly, densities of marsh periwinkle snails and southern ribbed mussels were manipulated inside fenced enclosures within a S. alterniflora salt marsh, and methane emissions and extracellular enzyme activities were measured over the course of a year. Southern ribbed mussels increased the emission of methane when present, but marsh periwinkle snail density had no effect. The data collected show that microbial community structure in wetlands are influenced by vegetation, that methane emission rates are plant species specific, and that southern ribbed mussels have the potential to increase methane emissions from S. alterniflora marshes.

The wetlands of Louisiana are losing area at the rapid rate of 42.9 km2 yr-1 and the trend is expected to continue. This combined with expected sea-level rise will likely cause large shifts in vegetation and salinity regimes that will affect the wildlife species reliant on these ecosystems. Waterbirds serve as indicator species of ecosystem health in estuarine wetland habitats; therefore, these species are often the targets of wetland management goals in Louisiana. However, many proposed wetland restoration projects are focused primarily on social impacts with only a few specific waterbird species designated for management. The majority of these waterbird habitat-use studies in Louisiana wetlands have focused on waterfowl species and their abundance in wetland habitats during migration and winter. My overall objective was to compare habitat use of all waterbird taxa in fresh and saline estuarine wetland habitats. Additionally, I examined habitat use at finer spatial scales to assess a possible preference for marsh edge microhabitats when compared to open water and interior emergent vegetation. I also investigated waterbird associations with the environmental parameters of emergent and aquatic species composition, percentage of open water, and salinity. From July 2014 to December 2015, I compared waterbird density and species richness both spatially and temporally to assess habitat use. I found that species richness differed between fresh and saline habitats depending on the month, with the month of April having the greatest species richness. Waterbird density was greatest among edge microhabitat regardless of salinity type, and birds utilized this habitat up to 15 m from the edge. Density did not vary in open water plots in relation to salinity type. The relationships between environmental variables and species were significant (p=0.002) as well as relationships between guilds and environmental variables (p=0.002). These data will be useful in attempts to simulate the effects of wetland loss and salinity changes on habitat quality for waterbirds in coastal Louisiana, and will inform habitat restoration and management decisions for optimal waterbird use.

The impacts of global change on ecosystems from climate change and invasive species are likely to be complex. Rising atmospheric CO2 concentrations, the associated climate forcing and greater frequency of extreme weather are serious challenges to natural ecosystems. In tandem with climate change, globalisation has led to the spread of invasive alien species around the globe that threaten to interrupt food web dynamics. Advancing understanding of the effects of global change on trophic interactions therefore requires study of interspecific and multi-trophic interactions. The aim of this thesis was to examine how host-plant heterogeneity, native–invasive species interactions and climate change effects (elevated atmospheric CO2 (eCO2) or drought) influence trophic interactions. An experimental approach was used which centred on a study system comprising the European raspberry (Rubus idaeus), the herbivorous large raspberry aphid (Amphorophora idaei) and coccinellid beetle predators (native species: Adalia bipunctata, Coccinella septempunctata; invasive alien species Harmonia axyridis). Under eCO2, R. idaeus resistance to A. idaei was unchanged for two cultivars (Glen Clova, Glen Ample) partially susceptible to A. idaei, but significantly reduced for another (Octavia) with complete resistance in ambient climatic conditions. The inclusion of a coccinellid predator, however, mitigated the reduction in the resistance of Octavia by reducing aphid abundance. Behavioural responses to predation by A. idaei were also impaired under eCO2 after feeding on Glen Ample. The role of natural enemies in controlling herbivore abundance in future climates is therefore crucial. Native coccinellid species are currently declining in much of Europe, attributed to the occurrence of the invasive species, H. axyridis. Despite the declines in native coccinellid species, it was found that behavioural modification to feeding by both native and invasive coccinellid species can, theoretically, result in coexistence. Plant resistance in a future climate is likely to be modified significantly. Reduced resistance to aphid herbivory demonstrated here mirrors previous studies, highlighting the future importance of natural enemies to control aphid abundance. Changes to the abundance and behaviour of aphid prey and intraguild predators will modify the effectiveness of native and invasive natural enemies. Further mechanistic research is required to understand multi-trophic interactions in dynamic environments.

Kinetochores are multi-protein machines that control chromosome movements by regulating the dynamics of attached microtubules. In human cells chromosome movements are orchestrated by the leading kinetochore tracking a shrinking microtubule whilst its sister tracks a growing microtubule. Directional switches occur when (both) kinetochore-attached microtubules fl ip between these two states, adaptive and coordinated switching then giving rise to the oscillations observed during metaphase. However the mechanisms (and rules) controlling directional switching are poorly understood. This work demonstrates that by tracking kinetochores with sub-pixel resolution in HeLa cells and fitting stochastic mathematical models that a sensor on the leading sister triggers switching when the tension across the centromeric spring connecting the sisters builds up sufficiently rapidly. Further it is shown that the trailing sisters polymerisation state is stabilised by high spring tension. These mechanisms pre-empt trail-first switching that would otherwise impose abnormal pulling forces between sister chromatids. As a consequence sister-switching is biased towards lead-first switching, switching of the trailing sister rapidly following as the spring tension falls, this removing the force dependent stabilisation of the trailing sisters K-fibre (kinetochore bound microtubules). This model explains how switching events are initiated and resolved, the centromeric spring tension providing a means for inter-sister communication and cross regulation that results in coordinated oscillations within a context of low spring tension. This study demonstrates that high throughput analysis and modelling pipelines can provide novel mechanistic insight into mechanochemical systems.

G protein-coupled receptors (GPCRs) are a superfamily of membrane proteins that bind to a diverse array of stimuli and are involved in a large number of physiological functions. The family A GPCRs are the largest and most comprehensively studied. The family B GPCRs are a small but important group of receptors (~15 members) that bind to peptide ligands and are involved in physiological processes that include vasodilation, stress, digestion and glucose homeostasis. The CGRP receptor is a unique member of this family as it is a heterodimer consisting of a GPCR subunit (calcitonin receptor-like receptor, CLR) and a single transmembrane accessory protein (receptor activity modifying protein, RAMP1). The extracellular loop two (ECL2) domain is involved in ligand binding and activation in a number of studied GPCRs. This makes it vital both with respect to receptor function and in the design of therapeutics. The main focus of this thesis is to study the structure and function of the ECL2 domain in the CGRP receptor. This was initially done through individual alanine substitutions of each ECL2 residue and measuring the effect of this on a number of receptor processes. Residues that were identified as important for receptor function through this investigation were selected for an extensive set of mutagenesis to identify the precise molecular interactions that were involved at each position. These experiments have shown that ECL2 is the most important domain of the CGRP receptor for ligand-based activation. The N-terminal half of ECL2 contains residues predicted to have structural function and the C-terminal half is predicted to be involved in direct ligand binding. These results have been used in collaboration to refine a computer model of receptor structure and ligand binding to predict specific ligand docking sites that can be used to design therapeutics for migraine, heart attack and hypertension. The final part of thesis produced preliminary data to support proof of concept for two techniques that can be used in the study of CGRP receptor function.

Patterns from hurricane damage give an indication that longleaf pine (Pinus palustris) is more windfirm than loblolly pine (Pinus taeda). Tree windfirmess has been attributed to many factors including species and material properties like wood strength and stiffness. Because longleaf pine wood is stronger and stiffer than loblolly pine wood, this study used static winching methodology to see if these properties account for differences in windfirmness by measuring bending force required to break stems (MMAX). Stress-strain diagrams were constructed for pulled trees to explore how they behave under increasing loads. Based on these diagrams, it appears that living trees can act as linear elastic materials as they experience increasing static lateral stress. As expected, longleaf pine stems were stiffer than loblolly pine wood in situ based on Youngs modulus of elasticity derived from these diagrams. Tree basal area was the best predictor of MMAX for both species, however, species had no effect on the maximum bending moment required to break tree stems of a given basal area for these trees under these conditions. The stiffness of the stems was higher for longleaf than loblolly as indicated by the modulus of elasticity, but the strength of the stems as indicated by the modulus of rupture was not significantly different between the species.

<p> The current landscape of small farms is approaching a major shift as more and more small farms are poised to come onto open marketplace around urban areas. A different farming business model called Community Supported Agriculture (CSA) has been utilized as new way for farmers to potentially earn above average revenue. However, small farmers still feel dissatisfied with their overall farm income, but when implementing the CSA business model the producers do feel that the CSA enhances their overall income satisfaction. Three essays were developed to examine this predicament. The first essay examined possible economic pricing models that a CSA is espoused to operating under, a multiproduct club good and monopoly. Utilizing these theories and data collected from prior research, I postulate that the CSA business model is not operating at the Pareto equilibrium because producers seem worse off and the shareholders are better off. The solution to this equilibrium problem seems to be two fold. One is that the producer is acting inefficiently and needs better control of their production and distribution. Second, the true cost of the product is not being communicate as espoused by CSA business model concept. Increasing efficiencies and fully communicating all costs to the shareholders are needed so that the correct consumers&rsquo; willingness to pay can be revealed and the Pareto optimal be achieved.</p><p> The second essay constructs and illustrates a mathematical model implemented by the gardening by the square foot method and expands it so that it can be applied by the CSA farmer. Comparing this planting method to other CSA row cropping models, the needed square footage for growing the need harvest can be reduced by 80%. Although the land needed is drastically decreased using this cropping method, labor costs have not been evaluated and field studies still need to be conducted. Also, this technique now segregates the shareholders production area from other production areas on the farm. This not only allows a CSA producer to better detail their specific production cost per shareholder but also has the advantage of allowing for more exclusion required to exert more monopoly or club good power, thus possibly correcting the dissatisfaction of producers&rsquo; personal income as described in essay one.</p><p> The third essay discusses the results of a survey, e-mailed to 673 producers listed on the USDA CSA website. The results of this survey were compared to previous CSA producer surveys and shows that not much has changed in the demographics of the CSA operations across the U.S. Using survey and census data, a linear regression econometric model was developed to explain full share pricing at CSAs. Five variable coefficients were found to have large impacts on full share prices. The variable of CSA farmers participating in other marketplaces had a negative impact of $294.62. When farmers used prices of other CSAs in their pricing, share prices were $120.82 higher. The preparation of the CSA harvest for distribution was found to have a negative effect on the price with a coefficient of $232.83. The factor of the management and labor of the family and shared risk coefficients were positive $226.45 and $169.65, respectively. Finally the weeks of harvest was positive with a coefficient of $12.38. All these variables were found to be significant at the 1% or 5% significance level. However, many other non-monetary attributes espoused in the literature as reasons for a producer choosing the CSA business model, did not have any discernable impact on pricing. More research is needed to clarify the value of these non-market items.</p>

Accumulating evidence indicates that oxygen free radicals are involved in many diseases and pathological conditions, such as aging, inflammation, reperfusion damage of ischemic tissue and various cardiovascular diseases. Extracellular superoxide dismutase (ECSOD) thus plays a major role in the maintenance of cells by providing protection against these toxic substances in the extracellular space. Various animal studies have shown that ECSOD has the ability to protect against many of these disorders, and interest has therefore evolved in the potential therapeutic use of the enzyme. However, despite strenuous efforts, large-scale production of the enzyme has not been achieved. To overcome this problem, a mimic of the enzyme, PseudoECSOD, has previously been constructed. This chimera is easy to produce in large amounts and has all the structural, enzymatic and heparin-binding characteristics of ECSOD, making it a potential substitute for ECSOD in therapeutic situations. However, the copper content of PseudoECSOD has been shown to be rather low, and since the copper ion is very important for the catalytic function of the enzyme, a production system that utilizes a copper chaperone for proper insertion of copper into the active site of the enzyme was constructed. The results show that the copper content of PseudoECSOD produced by this system is close to 100 %. In order to use PseudoECSOD therapeutically, further investigations of its binding capability and protective properties are needed. Therefore, the binding of ECSOD and PseudoECSOD to heparin was investigated using isothermal titration calorimetry. The results show that although some purely ionic interactions are important for the binding between ECSOD and heparin, there is also a substantial contribution from non-ionic interactions. The investigation also showed that the C-terminal domain is the only part of ECSOD that contributes to productive binding, and that the binding of PseudoECSOD and ECSOD to heparin is similar. In addition, analysis of mutant proteins strongly indicated that the amino acids R210, K211 and R214 are important for optimal binding of ECSOD to heparin, accounting for about 30 % of the total binding energy. The structural placement of these amino acids in an α-helix also confirms the hypothesis postulated by Margalit et al., that a common structural motif for heparin-binding proteins may be two positively charged amino acids at a distance of approximately 20 Å in the 3D-structure, facing opposite directions of a α-helix. The importance of these residues was also confirmed by analysis of a phage display library of the C-terminal domain of ECSOD. The binding of PseudoECSOD to heparan sulfate on cell surfaces of two different cell types, HepG2 and endothelial cells, was also investigated. The results clearly show that PseudoECSOD binds to these cells in a very similar manner to ECSOD. To investigate the protective properties of PseudoECSOD against ischemia-reperfusion injuries, an isolated rabbit heart model was used. The results indicate that the enzyme has a protective effect. However, more experiments using the rabbit heart and other animal models are needed to identify the optimal dose for protective purposes. The protective properties of PseudoECSOD in human tissue should also be thoroughly investigated. In summary, the findings in these studies, together with earlier results showing the close resemblance of PseudoECSOD to ECSOD in structural, enzymatic and heparin-binding properties, further support the proposition that PseudoECSOD may be a good substitute for ECSOD to use in therapeutic interventions.

Louisiana leads all U.S. states in blue crab (Callinectes sapidus) landings, but high fuel and bait costs have hindered commercial fishing productivity of Louisiana in recent years. The primary baitfish, Atlantic menhaden (Brevoortia tyrannus), has steadily increased in price and decreased in availability, while crab prices remain low. To reduce costs for fishermen, an alternative bait was developed that incorporates shrimp waste into a semi-rigid alginate matrix. Lab testing and preliminary field tests show that shrimp-alginate bait may be a suitable alternative to menhaden for Louisiana crab fishermen. I evaluated bait performance by conducting field sampling to compare catch rates and longevity of standard baitfish and shrimp-alginate bait. I performed seasonal fishery-independent testing at three sites across Southern Louisiana from summer 2014 to spring 2015, and tested the bait on commercial crabbing boats throughout coastal Louisiana during peak crab season in 2015. Catch rates of shrimp-alginate were less than menhaden overall, however, bait performance changed with site and season, and did not significantly differ when I evaluated commercially relevant crab classes. Analysis of remaining bait quantity after fishing showed that shrimp-alginate remains intact as long, or longer, than standard baitfish during peak crab fishing from June through August. After testing shrimp-alginate bait in the field, I evaluated the economic feasibility of producing the bait with a partial budget supply line. With its current formulation, shrimp-alginate can only be produced at a cost lower than menhaden (currently $0.50/lb.) under optimal production scenarios, however, slight modifications that improve shelf life could dramatically decrease the cost of bait production. Findings from both field work and feasibility analysis show promise in the alternative shrimp-alginate bait with given improvements to catch rate efficacy and product storage.