Forage sorghum (Sorghum bicolor L. Moench) is one of the prospective crops that may be used to produce biofuels in the future. Therefore, it is of interest to find management practices that improve both the production of biomass yield and quality. This study presents observations of the effects different rates of nitrogen fertilization have on yield, tissue nitrogen content, and tissue quality measures such as ash, lignin, sucrose, xylans, cellulose and starch content, based on three years of field trials from the Brazos Bottom and one year of field trials from near China, Texas. Data for the quality components were obtained using near infrared spectroscopy, with the exception of tissue nitrogen which was determined by using the dry combustion method. This study has showed fertilizer nitrogen had a strong positive correlation with the tissue nitrogen of sorghum biomass. Changes in tissue quality in relationship with fertilizer nitrogen levels and tissue nitrogen concentration were also observed. Ash showed a strong positive and sucrose showed a strong negative correlation to both tissue nitrogen concentration and fertilizer nitrogen application. Similarly to sucrose, starch also decreased with higher nitrogen levels and lignin was found to increase slightly. The concentration of cellulose and xylans were very weakly affected by nitrogen application and nitrogen concentration.

Malaria remains one of the world's major health problems, especially in developing countries. A better understanding of the pathology and pathophysiology of severe malaria is key to develop new treatments. Different approaches have been used in malaria research including the in vitro co-culture models with endothelial cells and both murine and simian animal models. However these are open to controversy due to disagreement on their representativeness of human disease. Using human post-mortem tissue in malaria research is another important approach but is practically challenging, limiting the availability of post mortem samples from malaria patients. The work in this thesis had two main themes. First I examined the role of the endothelial signalling Angiopoetin-Tie-2 receptor pathway in malaria. Ang-2 has been shown to be a significant biomarker of severe and fatal malaria. I examined the tissue specific expression of proteins from this pathway in post-mortem brain tissues from fatal malaria cases, but found no difference between cerebral malaria and non-cerebral malaria cases. Ang-2 correlated with the severity of malaria in these patients. An attempt to examine the interaction of hypoxia and the Ang-Tie-2 pathway in vitro using a co-culture model of human brain endothelial cells was unsuccessful due to contamination of the cell line. The second part of the thesis aimed to utilise molecular pathology techniques including miRNA and whole-genome microarrays. I have shown for the first time that these can be successfully applied to human post-mortem tissue in malaria. First I used archival tissues to examine the microRNA signature in the kidney of patients with malaria associated renal failure. Second I optimised a protocol to preserve post mortem tissue for molecular pathology, from an autopsy study in Mozambique. Using the subsequent total mRNA transcriptomic data and bioinformatics analysis this work has expanded our knowledge of differential gene expression and the families of genes which are dysregulated in the brain in response to malaria infection.