Maximizing efficiency in sunflower breeding through historical data optimization.

Genomic selection (GS) has become an increasingly popular tool in plant breeding programs, propelled by declining genotyping costs, an increase in computational power, and rediscovery of the best linear unbiased prediction methodology over the past two decades. This development has led to an accumulation of extensive historical datasets with genotypic and phenotypic information, triggering the question of how to best utilize these datasets. Here, we investigate whether all available data or a subset should be used to calibrate GS models for across-year predictions in a 7-year dataset of a commercial hybrid sunflower breeding program. We employed a multi-objective optimization approach to determine the ideal years to include in the training set (TRS). Next, for a given combination of TRS years, we further optimized the TRS size and its genetic composition. We developed the Min_GRM size optimization method which consistently found the optimal TRS size, reducing dimensionality by 20% with an approximately 1% loss in predictive ability. Additionally, the Tails_GEGVs algorithm displayed potential, outperforming the use of all data by using just 60% of it for grain yield, a high-complexity, low-heritability trait. Moreover, maximizing the genetic diversity of the TRS resulted in a consistent predictive ability across the entire range of genotypic values in the test set. Interestingly, the Tails_GEGVs algorithm, due to its ability to leverage heterogeneity, enhanced predictive performance for key hybrids with extreme genotypic values. Our study provides new insights into the optimal utilization of historical data in plant breeding programs, resulting in improved GS model predictive ability.

Prevalence of intestinal parasitic infections and associated risk factors among Kigali Institute of Education students in Kigali, Rwanda.

Intestinal parasitic infections (IPIs) are a significant public health problem in sub- Saharan Africa (SSA) and Rwanda is not spared. While eradication programs towards preschool-aged and school-aged children are undertaken, important gaps regarding IPIs among students attending tertiary learning institutions remain. The aim of this study was to determine the prevalence of IPIs and associated risk factors among Kigali Institute of Education (KIE) students who attended its medical clinic for stool examination. A cross-sectional study was carried out during the 2010 academic year, from February to July. Fresh stool samples were collected from 109 students chosen randomly and were examined for the presence of eggs, cysts and parasites using direct saline smear under light microscopy. A questionnaire was also used to assess water consumption habits, eating and living places. More than half (50.5%) of the stools examined were infected with an intestinal parasite. Among the infected students, prevalence of Entamoeba histolytica was 54.5%, Trichomonas intestinalis and Ascaris lumbricoides were 20.0%, Giardia duodenalis was 3.6% and Ancylostoma duodenale was 1.8%. The prevalence of IPIs was strongly associated with drinking any kind of water (p<0.001) and eating outside of the KIE cafeteria (p<0.001) and significantly related to living outside of the KIE campus (p=0.026). The study showed that IPIs of public health relevance are prevalent among students attending tertiary schools. The importance of living and eating in hygienic environments as well as drinking safe water is crucial and all efforts need to be sustained.

Prevalence of intestinal parasitic infections and associated risk factors among Kigali Institute of Education students in Kigali, Rwanda

Intestinal parasitic infections (IPIs) are a significant public health problem in sub- Saharan Africa (SSA) and Rwanda is not spared. While eradication programs towards preschool-aged and school-aged children are undertaken, important gaps regarding IPIs among students attending tertiary learning institutions remain. The aim of this study was to determine the prevalence of IPIs and associated risk factors among Kigali Institute of Education (KIE) students who attended its medical clinic for stool examination. A cross-sectional study was carried out during the 2010 academic year, from February to July. Fresh stool samples were collected from 109 students chosen randomly and were examined for the presence of eggs, cysts and parasites using direct saline smear under light microscopy. A questionnaire was also used to assess water consumption habits, eating and living places. More than half (50.5%) of the stools examined were infected with an intestinal parasite. Among the infected students, prevalence of Entamoeba histolytica was 54.5%, Trichomonas intestinalis and Ascaris lumbricoides were 20.0%, Giardia duodenalis was 3.6% and Ancylostoma duodenale was 1.8%. The prevalence of IPIs was strongly associated with drinking any kind of water (p<0.001) and eating outside of the KIE cafeteria (p<0.001) and significantly related to living outside of the KIE campus (p=0.026). The study showed that IPIs of public health relevance are prevalent among students attending tertiary schools. The importance of living and eating in hygienic environments as well as drinking safe water is crucial and all efforts need to be sustained.

Functional proteomic analysis of melanoma progression.

Functional proteomics provides a powerful approach to screen for alterations in protein expression and posttranslational modifications under conditions of human disease. In this study, we use protein screening to examine markers of melanoma progression, by profiling melanocyte versus melanoma cell lines using two-dimensional electrophoresis and mass spectrometry. Eight candidate markers were identified as differentially regulated in transformed cells. In particular, hepatoma-derived growth factor (HDGF) and nucleophosmin B23 were strongly correlated with melanoma. Nucleophosmin B23 is a nucleolar and centrosome-associated protein, which has been implicated as a target for cyclin E/cyclin-dependent kinase 2 (CDK2) in modulating centrosome duplication and cell cycle control. Western blotting of one-dimensional and two-dimensional gels showed that the form of nucleophosmin B23 that is up-regulated in melanoma represents a posttranslationally modified form, most likely reflecting enhanced phosphorylation in the tumor-derived cells. In contrast, Western analysis of HDGF demonstrated increased expression of all forms in melanoma cell lines compared with melanocytes. Immunohistochemical analysis of human tissue biopsies showed strong expression of HDGF in early and late stage melanomas and low expression in melanocytes and nontumorigenic nevi. Interestingly, biopsies of nevi showed a graded effect in which HDGF immunoreactivity was reduced in nevoid nests penetrating deep into the dermis compared with nests at the epidermal-dermal junction, suggesting that HDGF expression in nevi is dependent on epidermal cell interactions. In contrast, biopsies of melanoma showed strong expression of HDGF throughout the tumor, including cells located deeply within dermis. Thus, expression of this antigen likely reports a reduced dependence of protein expression on epidermal interactions.