African Americans experience a disproportionate mortality, morbidity, and disability associated with ischemic stroke. Traditional risk factors offer some explanation for this finding, but novel risk factors have not been explored. APOE4 genotype, which is more prevalent in African Americans demonstrate a pro-inflammatory phenotype that may result in an exaggerated inflammatory response associated with ischemic stroke, resulting in worse outcomes. The purpose of this study was to examine relationships among APOE genotypes, inflammatory markers (CD11β, platelet leukocyte aggregates, IL-1β, IL-6, IL-8, and tissue necrosis factor alpha), the anti-inflammatory marker, IL-10, and risk factors (hypertension, diabetes type II, obesity, hyperlipidemia, and smoking) in African Americans at 3 days post stroke. Twenty five patients were enrolled with 12 patients in the APOE4 group and 13 patients in the non-APOE4 group. In the APOE4 group, 75% were male compared to 54% in the non-APOE4 group. The average age in the APOE4 group was 56.5 ± 9.0 compared to 66 ± 16.0 years in the non-APOE4 group. Females in the APOE4 group were younger with ages comparable to men. All participants had hypertension. Forty two percent of patients in the APOE4 group had two risk factors and 46% of patients in the non-APOE4 group had three risk factors. Major findings included 1) there were no statistical difference between inflammatory markers and APOE genotypes, and 2) the APOE4 carrier was not a predictor for overall inflammatory load among African Americans with ischemic stroke. The study was underpowered and small effect sizes were not sufficient to create statistical findings. This was the first study to examined APOE genotypes, inflammatory markers, and risk factors among African Americans with ischemic stroke. More studies are needed to not only investigate novel risk factors, but to also characterize inflammatory and genetic mechanisms with ischemic stroke and their associated outcomes among African Americans. Such studies may lead to primary and secondary prevention of ischemic stroke and reduce the health disparities associated with ischemic stroke among African Americans.

In 2007, U.S. Congress created the "Energy Independence and Security Act" with primary goals focused on increasing the knowledge in production of renewable fuels, increasing the percentages of renewable fuels in the transportation sector and decreasing the emissions of greenhouse gases from fossil fuel sources. To achieve these goals, many species have been pointed as sources of feedstock for the biofuel industry. Photoperiod sensitive (PS) biomass sorghum for the lignocellusosic based conversion is one. In this study, three main objectives were addressed regarding the relative performance for biomass yield and biomass composition of PS biomass sorghum. First, genetic and environmental variation effects on the biomass yield and biomass composition, and usefulness of pre-classification of genotypes by biomass lignin content were evaluated. On the set of genotypes and locations tested, the environmental effect had the largest influence on the biomass composition, yield and its components. Although smaller, the genetic variation effect was significant for most of the traits, some traits had significant genotype by environment GXE interaction. The pre-classification of genotypes according to lignin content proved to be an efficient system of separating genotypes as groups, but failed to be efficient in separating on the entries bases. Assessment of growth patterns for biomass yield and composition, characterized photoperiod sensitive sorghum as capable of producing a harvestable crop as soon as 4 months, but variations in the concentration of constituents and moisture percentage, pointed to a harvest window that can be extended up to the 7th month after planting. Genetic variation was observed in this trail for most agronomic and composition traits, but a strong environmental effect was also observed. Lastly, the influence of three diverse cytoplasm male sterility (CMS) systems in biomass sorghum hybrids was assessed. The presence of A1, A2 or A3 CMS in the hybrids tested in this study had no influence on the biomass yield performance or in the biomass composition. Therefore, any of the CMS systems can be used in the production of biomass sorghum hybrid seed. Also, in this trial the environmental effects were significant and strong for most traits evaluated.

Researchers are frequently faced with the problem of analyzing incomplete and often unbalanced genotype-by-environment (GxE) matrices which arise as a trials programme progresses over seasons. The principal data for this investigation, arising from a ten year programme of onion trials, has less than 2,300 of the 49,200 combinations from the 400 genotypes and 123 environments. This 'sparsity' renders standard GxE methodology inapplicable. Analysis of this data to identify onion varieties that suit the shorter, hotter days of tropical and subtropical locations therefore presented a unique challenge. Removal of some data to form a complete GxE matrix wastes information and is consequently undesirable. An incomplete GxE matrix can be analyzed using the additive main effects and multiplicative interaction (AMMI) model in conjunction with the EM algorithm but proved unsatisfactory in this instance. Cluster analysis has been commonly used in GxE analyses, but current methods are inadequate when the data matrix is incomplete. If clustering is to be applied to incomplete data sets, one of two routes needs to be taken: either the clustering procedure must be modified to handle the missing data, or the missing entries must be imputed so that standard cluster analysis can be performed. A new clustering method capable of handling incomplete data has been developed. 'Two-stage clustering', as it has been named, relies on a partitioning of squared Euclidean distance into two independent components, the GxE interaction and the genotype main effect. These components are used in the first and second stages of clustering respectively. Two-stage clustering forms the basis for imputing missing values in a GxE matrix, so that a more complete data array is available for other GxE analyses. 'Two-stage imputation' estimates unobserved GxE yields using inter-genotype similarities to adjust observed yield data in the environment in which the yield is missing. This new imputation method is transferrable to any two-way data situation where all observations are measured on the same scale and the two factors are expected to have significant interaction. This simple, but effective, imputation method is shown to improve on an existing method that confounds the GxE interaction and the genotype main effect. Future development of two-stage imputation will use a parameterization of two-stage clustering in a multiple imputation process. Varieties recommended for use in a certain environment would normally be chosen using results from similar environments. Differing cluster analysis approaches were applied, but led to inconsistent environment clusterings. A graphical summary tool, created to ease the difficulty in identifying the differences between pairs of clusterings, proved especially useful when the number of clusters and clustered observations were high. 'Cluster influence diagrams' were also used to investigate the effects the new imputation method had on the qualitative structure of the data. A consequence of the principal data's sparsity was that imputed values were found to be dependent on the existence of observable inter-genotype relationships, rather than the strength of these observable relationships. As a result of this investigation, practical recommendations are provided for limiting the detrimental effects of sparsity. Applying these recommendations will enhance the future ability of two-stage imputation to identify those onion varieties that suit tropical and subtropical locations.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.