Search

Cowpea (Vigna unguiculata (L.) walp) is a legume crop mainly grown on small scale in low–input farming systems in Uganda. Cowpea bacterial blight (CoBB) disease caused by Xanthomonas axonopodis pv. vignicola (Burkh.) Dye is increasingly becoming a major hindrance to cowpea productivity. Sixty-four cowpea genotypes were evaluated for their response to bacterial blight disease (CoBB). Field experiments were carried out during the first and second rainy seasons using alpha lattice design with three replications. Data on disease incidence and severity, grain yield, days to 50% flowering, number of seeds per pod, pod length, number of peduncles per plant, and number of branches per plant were collected. Disease severity and incidence data was used to determine relative Area Under Disease Progress Curve (rAUDPC). Results showed significant differences (P ≤ 0.001) among the genotypes for rAUDPC in each season. The rAUDPC across the seasons indicated that genotypes NE 32, WC 32A, WC 26 and NE 44 with rAUDPC values ranging from 0.22 to 0.26 were resistant to CoBB whereas genotypes NE 31 and NE 40 with rAUDPC values 0.44 and 0.46 respectively were susceptible. The rAUDPC did not show any significant correlation with days to 50% flowering, yield and its components. This study suggested that the genotypes NE 32, WC 32A, NE 44, and WC 26 be used as prospective parents in breeding initiatives to develop bacterial blight-resistant varieties due to their high yields and resistance to CoBB.

The low productivity of cowpea is partly attributed to a number of constraints including diseases such as cowpea bacterial blight (CoBB). Cowpea bacterial blight has the capacity to cause up to 92% yield loss under severe infections. The objective of this study was to determine the combining ability for resistance to CoBB among cowpea genotypes in Uganda. Nine selected parents were crossed to produce 63 progenies. F1 progenies were evaluated and data gathered included days to 50% flowering, CoBB disease scores and grain yield. The mean squares for rAUDPC due to GCA and SCA effects were significant (P≤0.001) and non-significant respectively. The broad sense coefficient of genetic determination (BCGD) and narrow sense coefficient of genetic determination (NCGD) were 44.3% and 29.1% respectively for rAUDPC. Parents WC 26 (-0.023) and NE 31 (-0.035) had highly significant negative GCA effects for rAUDPC and were therefore good general combiners for this trait. Crosses SECOW 3B x ACC 26 X SECOW 1T and WC 26 x NE 32 had negative significant SCA effect for rAUDPC with a values of -0.073 and -0.06, respectively while Crosses ACC 26 x SECOW 1T x NE 40 (-0.07) and NE 40 x WC 26 (-0.06) had significant negative reciprocal effects for rAUDPC. This study revealed that genetic inheritance for cowpea bacterial blight was controlled predominantly by additive gene effects. Parents WC 26 and NE 31 identified as good general combiners for resistance to CoBB could be utilized as sources of resistance while Crosses SECOW 3B x ACC 26 X SECOW 1T, WC 26 x NE 32, ACC 26 X SECOW 1T x NE 40 and NE 40 x WC 26 that were the best specific combiners for resistance to CoBB could be put under further evaluation as potential varieties.

Soybean is a high oil and protein-rich legume with several production constraints. Globally, several fungi, viruses, nematodes, and bacteria cause significant yield losses in soybean. Coniothyrium glycines (CG), the causal pathogen for red leaf blotch disease, is the least researched and causes severe damage to soybean. The identification of resistant soybean genotypes and mapping of genomic regions associated with resistance to CG is critical for developing improved cultivars for sustainable soybean production. This study used single nucleotide polymorphism (SNP) markers generated from a Diversity Arrays Technology (DArT) platform to conduct a genome-wide association (GWAS) analysis of resistance to CG using 279 soybean genotypes grown in three environments. A total of 6395 SNPs was used to perform the GWAS applying a multilocus model Fixed and random model Circulating Probability Unification (FarmCPU) with correction of the population structure and a statistical test p-value threshold of 5%. A total of 19 significant marker–trait associations for resistance to CG were identified on chromosomes 1, 5, 6, 9, 10, 12, 13, 15, 16, 17, 19, and 20. Approximately 113 putative genes associated with significant markers for resistance to red leaf blotch disease were identified across soybean genome. Positional candidate genes associated with significant SNP loci-encoding proteins involved in plant defense responses and that could be associated with soybean defenses against CG infection were identified. The results of this study provide valuable insight for further dissection of the genetic architecture of resistance to CG in soybean. They also highlight SNP variants and genes useful for genomics-informed selection decisions in the breeding process for improving resistance traits in soybean.

Key message We identified markers associated with GRD resistance after screening an Africa-wide core collection across three seasons in Uganda Abstract Groundnut is cultivated in several African countries where it is a major source of food, feed and income. One of the major constraints to groundnut production in Africa is groundnut rosette disease (GRD), which is caused by a complex of three agents: groundnut rosette assistor luteovirus, groundnut rosette umbravirus and its satellite RNA. Despite several years of breeding for GRD resistance, the genetics of the disease is not fully understood. The objective of the current study was to use the African core collection to establish the level of genetic variation in their response to GRD, and to map genomic regions responsible for the observed resistance. The African groundnut core genotypes were screened across two GRD hotspot locations in Uganda (Nakabango and Serere) for 3 seasons. The Area Under Disease Progress Curve combined with 7523 high quality SNPs were analyzed to establish marker-trait associations (MTAs). Genome-Wide Association Studies based on Enriched Compressed Mixed Linear Model detected 32 MTAs at Nakabango: 21 on chromosome A04, 10 on B04 and 1 on B08. Two of the significant markers were localised on the exons of a putative TIR-NBS-LRR disease resistance gene on chromosome A04. Our results suggest the likely involvement of major genes in the resistance to GRD but will need to be further validated with more comprehensive phenotypic and genotypic datasets. The markers identified in the current study will be developed into routine assays and validated for future genomics-assisted selection for GRD resistance in groundnut.

Different sectors globally are experiencing the impacts of changing climate and water resources are among them. This study was conducted with an aim of examining the community views regarding the effect of changing climate on water demand over the River Mpanga Water Catchment. The study employed a cross-sectional survey using 111 household interviews; 14 Focus Group Discussions (FGDs) and 27 key informants interviews (KII). This study considered 14 villages and employed a mixed-methods study design. The analysis was conducted using SPSS software to derive the descriptive statistics. Qualitative information was analyzed using content analysis to conduct an in-depth analysis. The study found that the main source of water is tap water (72.1%) and the main use of water in the study area is domestic water use. This study also found that, breakage in water supply especially during the dry season (10 out of 14 FGDs) and poor quality of water especially the tap water due to chemical treatment (11 out of 14 FDGs) were the major challenges of water the community faced. Additionally, this study observed that 15 out of 27 KII considered drought as a major threat and that the area had experienced decreases in rainfall amounts over the months of January and February. Therefore, this study recommends that the providers of domestic water should invest heavily in technologies for improving water quality and amount; ensure sustainable and equitable rationing of water during scarcity; and promote incentives for water harvesting. Key words: Community survey, water resources, River Mpanga.

Soybean (Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean accessions, therefore, evaluate soybean value in terms of use for breeding purposes. To accomplish this, a set of 282 soybean accessions were genotyped using the Diversity Array Technology Sequencing with a high throughput of the Single-nucleotide polymorphisms (SNPs). A total of 6,935 high-quality SNPs were identified across the whole soybean genome. The mean value of genetic diversity, major alleles frequency, minor alleles frequency, expected heterozygosity, and the polymorphism information content was respectively estimated at 0.35, 0.77, 0.22, 0.33, and 0.29. The analysis of molecular variance reveals that the variance among the populations is lower than the variance within the populations. The soybean accessions could be classified into two groups based on the model-based population structure and the principal coordinate analysis or into three groups based on the discriminant analysis of the principal component and the Neighbor-joining tree. The information provided in this study will be helpful for breeders.

Background: Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and is characterised by hy- perproliferation of malignant lymphocytes in the bone marrow. Rarely, ALL may be preceded by a period of pancytopenia and bone marrow hypoplasia which spontaneously recovers. This phenomenon, which has not before been described in T-cell ALL, is referred to as transient bone marrow hypoplasia. Case presentation: A 5-year-old boy who presented with high-grade fever and generalised lymphadenopathy, was found to have pancytopenia on peripheral blood count and bone marrow hypoplasia. He was observed over a one-month period during which his bone marrow and peripheral blood counts recovered spontaneously. Symptoms recurred after 4 months and he was found to have blast infiltration of the bone marrow and diagnosed with T-cell ALL. Conclusion: Cases of transient bone marrow hypoplasia or overt aplastic anemia with spontaneous recovery and then followed by B-cell ALL or Acute Myeloid Leukemia have been described previously in the medical literature. This is the first case of transient bone marrow hypoplasia resulting into ALL of T-cell immunophenotype. While marrow hypoplasia preceding ALL remains poorly understood, it suggests an antecedent environmental insult to lymphoid progenitors or a germline abnormality that predisposes to lymphoid dysplasia. This may provide clues to the hitherto unknown pathophysi- ological process and etiological factors that precede the majority of childhood ALL cases. This case enlightens pediatricians about the existence of such rare cases so as to periodically follow up children with pancytopenia and/or bone marrow hy- poplasia for prolonged periods even after apparent recovery. Keywords: Pancytopenia, hypoplasia; aplastic anemia; T-cell acute lymphoblastic leukemia; case report.

HIV and sickle cell disease (SCD) are significant causes of morbidity and mortality in sub-Saharan Africa. Given their separate roles in immune dysregulation, our objective was to characterise the impact that SCD has on the presentation and progression of paediatric HIV.The study was a retrospective cohort study (study period 2004-2018). Cases of HIV + and SCD-afflicted patients (HIV+/SCD+) were obtained via electronic chart review from a paediatric HIV clinic in Kampala, Uganda and matched 1:3 with HIV + controls without SCD (HIV+/SCD-).Thirty-five HIV+/SCD + subjects and 95 HIV+/SCD- controls were analysed (39% female (51/130), age 3.6 years (SD3.9)). At baseline, WHO clinical stage (64% total cohort Stage III/IV) and nutritional status (9.4% severe acute malnutrition) were similar for both groups, whereas HIV+/SCD + had higher though non-significant baseline CD4 count (1036 (SD713) vs 849 (SD638) cells/microlitre, P = 0.20, two-tailed t-test). There were 19 deaths, 6 (17%) HIV+/SCD + and 13 (14%) HIV+/SCD-, with unadjusted/adjusted models showing no significant difference. Nutritional progression and clinical stage progression showed no significant differences between groups. Kaplan-Meier analysis showed a slower rate of treatment failures in the HIV+/SCD + cohort (P = 0.11, log-rank survival test). Trajectory analysis showed that in the time period analysed, the HIV+/SCD + cohort showed a more rapid rise and higher total CD4 count (P = 0.012, regression analysis).The study suggests that SCD does not adversely affect the progression of HIV in patients on ART. Further, HIV+/SCD + achieved higher CD4 counts and fewer HIV treatment failures, suggesting physiological effects due to SCD might mitigate HIV progression.Le VIH et la drépanocytose (SCD) sont des causes importantes de morbidité et de mortalité en Afrique subsaharienne. Compte tenu de leurs rôles distincts dans la dérégulation immunitaire, notre objectif était de caractériser l'impact du SCD sur la présentation et la progression du VIH pédiatrique. MÉTHODES: Etude de cohorte rétrospective (période d'étude 2004-2018). Les cas de patients VIH+ atteints de SCD (VIH+/SCD+) ont été obtenus par analyse des dossiers électroniques dans une clinique pédiatrique du VIH à Kampala, en Ouganda et appariés dans une proportion 1:3 avec des témoins VIH+ sans SCD (VIH+/SCD-). RÉSULTATS: 35 sujets VIH+/SCD+ et 95 témoins VIH+/SCD- ont été analysés (39% de femmes (51/130), 3,6 ans d’âge (SD3,9)). Au départ, le stade clinique de l'OMS (64% de la cohorte totale au stade III/IV) et l'état nutritionnel (9,4% de malnutrition aiguë sévère) étaient similaires pour les deux groupes, tandis que les VIH+/SCD+ avaient un nombre de CD4 de base plus élevé mais non significatif (1036 (DS, 713) vs 849 (DS, 638) cellules/microlitre, p = 0,20, test t bilatéral). Il y a eu 19 décès, 6 (17%) VIH+/SCD+ et 13 (14%) VIH+/SCD-, avec des modèles non ajustés/ajustés ne montrant aucune différence significative. La progression nutritionnelle et la progression du stade clinique n'ont montré aucune différence significative entre les groupes. L'analyse de Kaplan-Meier a montré un taux d'échecs de traitement plus lent dans la cohorte VIH+/SCD+ (p = 0,11, test de survie log-rank). L'analyse de la trajectoire a montré que dans la période analysée, la cohorte VIH+/SCD+ a montré une augmentation plus rapide et un nombre total de CD4 plus élevé (p = 0,012, analyse de régression).L'étude suggère que SCD n'affecte pas négativement la progression du VIH chez les patients sous ART. De plus, les patients VIH+/SCD+ ont atteint un nombre plus élevé de CD4 et moins d'échecs de traitement du VIH, ce qui suggère que les effets physiologiques dus à la SCD pourraient atténuer la progression du VIH.

Lightning has received a lot of attention in scientific literature during the recent decade, not only because it is an impressive atmospheric phenomenon but also its associations with severe storms that cause unprecedented damages to agriculture, electric power networks, property, and life. This study assessed the Spatio-temporal characteristics of lightning occurrence with elevation in Uganda using lightning flash and elevation datasets for a period of fifteen years (1998-2013). Datasets used in this study included daily lightning flashes as captured by Lightning Imaging Sensor (LIS) aboard on Tropical Rainfall Measurement Mission (TRMM) satellite and elevation data in form of Digital Elevation Model (DEM) obtained from the Shuttle Radar Topography Mission (SRTM). Spatio-temporal results indicated that ~80% of areas with an elevation that ranges from 800-1200 m above mean sea level (masl) in Uganda had severe lightning occurrences and ~20% of areas with an elevation greater than 1200 m (masl) had severe lightning occurrences. The country received an enhanced number of lighting events with the highest number in 1999. Subsequently, a reduced trend was observed from 2002 to 2007 followed by an increment in the number of lightning events in (2010, 2011, 2012, and 2013). The intensity of the events decreased gradually though two peaks were observed, (1998-2001) and (2010-2013). Furthermore, results indicate escalations in the frequency and duration of lightning events from 60 times in 1998 to approximately 200 times in 2013 and from 1000 microseconds in 1998 to more than 2000 microseconds in 2013. Generally, the country experienced an enhanced increase in lighting occurrences over the study period which therefore calls for urgent actions to combat the root cause and also provide effective measures to reduce the impacts of lightning strikes.

The changing climate has negatively impacted food systems by affecting rainfall patterns and leading to drought, flooding, and higher temperatures which reduce food production. This study examined the ability of communities to cope with food insecurity due to the changing climate in the Serere and Buyende districts, which are two different agro-ecological zones of Uganda. We administered 806 questionnaires to households, a sample size which was determined using Yamane’s formula, with the snowball sampling method used to select the households. The questionnaire sought information, including that regarding the respondents’ resources, the effects of climate change on households, and the coping mechanisms employed to reduce the impact of climate change on food security. The data collected was coded and analyzed using the statistical package for the social sciences (SPSS). Agriculture was found to be the main source of income for 42.4% of male adults and 41.2% of female adults in Serere. In Buyende, 39.9% of males and 33.7% of females rely on selling animal, poultry, and food crops. Aggregate results further showed that 58.3% of females and 42.2% of the males from both districts had suffered from the impacts of climate change, and that the effects were more evident between March and May, when communities experienced crop failure. The study further found that the percentage of households who had three meals a day was reduced from 59.7% to 43.6%, while the number of households with no major meals a day increased from 1.3% to 1.6%. We also found that 34.3% of households reported buying food during periods of crop failure or food scarcity. Moreover, despite reporting an understanding of several coping mechanisms, many households were limited in their ability to implement the coping mechanisms by their low incomes. This reinforced their reliance on affordable mechanisms, such as growing drought-resistant crops (32.7%), rearing drought-resistant livestock breeds (26.1%), and reducing the number of meals a day (14.5%), which are mechanisms that are insufficient for solving all the climate-related food insecurity challenges. We recommend that the government intervenes by revising policies which help farmers cope with the negative effects of climate change, promoting the sensitization of farmers to employing the coping mechanisms, and subsidizing agricultural inputs, such as resistant varieties of crops, for all to afford.

Drought occurrences in Rakai district take a strange model and it has been rampantly increasing causing reduced income levels for farmers, reduced farm yields, increased food insecurity and migration, wetland degradation, illness and loss of livestock. The purpose of this study was to investigate past and future characteristics of drought due to climate change in Rakai district. Datasets used include dynamically downscaled daily precipitation and temperature data from Coordinated Regional Climate Downscaling Experiment (CORDEX) at 0.44°×0.44° resolution over the Africa domain. R software (Climpact2 package), was used to generate SPI values, Mann Kendall trend test and Inverse Distance Weighting methods were used to examine temporal and spatial drought characteristics respectively. Results depicted more extreme and severe drought conditions for SPI12 under historical compared to SPI3,Kakuto, Kibanda and Lwanda sub counties were the most drought hot spot areas, positive trends of drought patterns for both time scales were observed, though only significant under SPI12. Projected results revealed extreme and severe drought conditions will be observed under RCP8.5 SPI12, and the least will be under RCP8.5 SPI3 and SPI12. Results further reveal that Kakuto, Kibanda, Kiziba, Kacheera, Kyalulangira, Ddwaniro and Lwanda sub counties will be the most drought hot spot sub counties across all time scales. Generally projected results reveals that the district will experience more drought conditions under RCP8.5 compared to RCP4.5 for time scale SPI12 and therefore urgent actions are needed.

Viruses limit sweetpotato (Ipomoea batatas) production worldwide. Many sweetpotato landraces in East Africa are, however, largely virus-free. Moreover, some plants infected by the prevalent Sweet potato feathery mottle virus (SPFMV) may be able to revert to virus-free status. In this study, we analysed reversion from SPFMV, Sweet potato virus C, Sweet potato mild mottle virus, Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato leaf curl Uganda virus using the indicator plant I. setosa and PCR/reverse-transcriptase PCR. We also investigated environmental factors (temperature and soil nutrients) that may influence reversion from virus infection. We tested reversion in the East African cultivars New Kawogo, NASPOT 1 and NASPOT 11, and the United States cultivars Resisto and Beauregard. Reverted plants were asymptomatic and virus was undetectable in assayed parts of the plant. After graft inoculation, only the East African cultivars mostly reverted at a high rate and from most viruses though cultivar Beauregard fully reverted following sap inoculation with Sweet potato virus C. None of the tested cultivars fully reverted from single or double infections involving SPCSV, and reversion was only observed in co-infections involving potyviruses. Root sprouts derived from SPFMV-reverted plants were also virus free. Reversion generally increased with increasing temperature and by improved soil nutrition. Overall, these results indicate variation in reversion by cultivar and that the natural ability of sweetpotato plants to revert from viruses is malleable, which has implications for both breeding and virus control.

Sweet potato feathery mottle virus (SPFMV) causes 50% yield losses in sweetpotato (Ipomoea batatas). However, some cultivars have been observed to become SPFMV free following initial infection, a phenomenon termed reversion. The heritability of reversion from virus infections in sweetpotato remains unclear. This study is aimed at determining heritability of reversion from SPFMV in progeny of crossed reverting and non-reverting sweetpotato cultivars ‘New Kawogo’ and ‘Resisto,’ respectively. Molecular diversity of the parents and progeny was also assessed using simple sequence repeats (markers) derived from coding regions of RNA dependent RNA polymerase 1 and dicer-like 1 gene that may be associated with reversion. Reversion potential varied among the progeny; 11 progeny reverted more effectively than ‘New Kawogo’ by 4 weeks after inoculation. Broad and narrow sense heritability was 76.42 and 42.4%, respectively. There was molecular variation among the 50 progeny, and markers ibDCL2b and ibDCL1a7F differentiated the progeny. These results indicate reversion was a heritable trait determined by multiple genes, and that genetic markers ibDCL2b and ibDCL1a7F may be used to differentiate the progeny. It is recommended that the progeny be tested in agro-ecological trials in virus-prone areas to identify those that deliver high yields and revert from SPFMV infection. Key words: Sweet potato feathery mottle virus, reversion, simple sequence repeats.

Purple-fleshed sweetpotato varieties are important for their nutraceutical value due primarily to their high anthocyanin content. These varieties also often have high dry matter content preferred by consumers and processors in sub-Saharan Africa. However, improved purple-fleshed sweetpotatoes are not available in Uganda. This study was conducted to evaluate the adaptability of purple-fleshed sweetpotato genotypes for storage root yield, dry matter and anthocyanin content in Uganda. A bi-parental population of 159 clones from the cross NCP06-020 NC09-188 introduced to Uganda from North Carolina State University was evaluated with three local checks in two sites and two seasons in Uganda. The trials were planted in two locations using alpha lattice design with two replicates and five sweetpotato vine cuttings per genotype. Storage roots and vines were harvested after five months and the agronomic characteristics were recorded. Dry matter and anthocyanin content of storage roots were analysed after harvesting. The mean storage root yield of clones across the two locations was 37.8 t/ha and 24.2 t/ha in the first season (2015A) and second season (2015B); respectively, with an overall mean of 31.0 t/ha. Storage root dry matter content ranged from 21.5 to 33.7% across locations and seasons with an overall mean of 29.1%. Storage root anthocyanin content across the two locations ranged from 0 to 12.6 mg/100g FW with the overall mean of 3.9 mg/100g FW. A total of ten genotypes showed significantly stable performance (P

East African countries (Uganda, Kenya, Tanzania, Rwanda, and Burundi) are prone to weather extreme events. In this regard, the past occurrence of extreme rainfall events is analyzed for 25 stations following the Expert Team on Climate Change Detection and Indices (ETCCDI) regression method. Detrended fluctuation analysis (DFA) is used to show the future development of extreme rainfall events. Pearson’s correlation analysis is performed to show the relationship of extreme rainfall events between different rainfall zones and their association with El Nino-Southern Oscillation (ENSO) and Indian Ocean dipole Mode Index (DMI). The results revealed that the consecutive wet days (CWD) index experienced a decreasing trend in 72% of the stations analyzed. Moreover, the consecutive dry days (CDD) index also indicated a positive trend in 44% of the stations analyzed. Heavy rainfall days index (R10mm) showed a positive trend at 52% of the stations and was statistically significant at a few stations. In light of the extremely heavy rainfall index (R25mm), 56% of the stations revealed a decreasing trend for the index and statistically significant trend at some stations. Further, a low correlation coefficient of extreme rainfall events between the regions (r2 = − 0.27 to r2 = 0.38) and between rainfall extreme indices with the atmospheric teleconnection indices [Dipole Mode Index (DMI) and Nino 3.4] ranging from r2 = − 0.1 to r2 = 0.35 was exhibited. Most rainfall zones showed a positive correlation between the R95p index and DMI, while 5/8 of the rainfall zones experienced a negative correlation between Nino 3.4 index and the R95p Index. In light of the highly variable trends of extreme rainfall events, we recommend planning adaptation and mitigation measures that consider the occurrence of such high variability. Measures such as rainwater harvesting, storage, and use during needs, planned settlement, and improved drainage systems management supported by accurate climate and weather forecasts are highly advised.

Genomic selection (GS) can accelerate variety release by shortening the variety development phase when factors that influence prediction accuracies (PA) of genomic prediction (GP) models such as training set (TS) size and relationship with the breeding set (BS) are optimized beforehand. In this study, PAs for the resistance to fall armyworm (FAW) and maize weevil (MW) in a diverse tropical maize panel composed of 341 double haploid and inbred lines were estimated using 16 parametric, semi-parametric, and nonparametric algorithms with a 10-fold and 5 repetitions cross-validation strategy. For MW resistance, 126 lines that had both genotypic and phenotypic data were used as a TS (37% of the panel) and the remaining lines, with only genotypic data, as a BS. Regarding FAW damage resistance, two TS determination strategies, namely: random-based TS (RBTS) with increasing sizes (37, 63, 75, and 85%) and pedigree-based TS (PBTS) were used. For both MW and FAW resistance datasets with an RBTS of 37%, PAs achieved with phenotypic best linear unbiased predictors were at least as twice as higher than those realized with best linear unbiased estimators. The PAs achieved with BLUPs for MW resistance traits varied from 0.66 to 0.82. The PAs with BLUPs for FAW resistance datasets ranged from 0.694 to 0.714 for RBTS of 37%, and 0.843 to 0.844 for RBTS of 85%. The PAs with BLUPs for FAW resistance with PBTS were generally high varying from 0.83 to 0.86, except for the third dataset which had the largest TS (86.22% of the panel) with PAs ranging from 0.11 to 0.75. GP models showed generally similar predictive abilities for each trait while the TS designation was determinant. There was a highly positive correlation (R=0.92***) between TS size and PAs for the RBTS approach while, for the PBTS, these parameters were highly negatively correlated (R=-0.44***), indicating the importance of the relationship between the TS and the BS with the smallest TS (31%) achieving the highest PAs (0.86). This study paves the way towards the use of GS for maize resistance to insect pests in sub-Saharan Africa.

Genomic selection (GS) can accelerate variety release by shortening variety development phase when factors that influence prediction accuracies (PA) of genomic prediction (GP) models such as training set (TS) size and relationship with the breeding set (BS) are optimized beforehand. In this study, PAs for the resistance to fall armyworm (FAW) and maize weevil (MW) in a diverse tropical maize panel composed of 341 double haploid and inbred lines were estimated. Both phenotypic best linear unbiased predictors (BLUPs) and estimators (BLUEs) were predicted using 17 parametric, semi-parametric, and nonparametric algorithms with a 10-fold and 5 repetitions cross-validation strategy. n. For both MW and FAW resistance datasets with an RBTS of 37%, PAs achieved with BLUPs were at least as twice as higher than those realized with BLUEs. The PAs achieved with BLUPs for MW resistance traits: grain weight loss (GWL), adult progeny emergence (AP), and number of affected kernels (AK) varied from 0.66 to 0.82. The PAs were also high for FAW resistance RBTS datasets, varying from 0.694 to 0.714 (for RBTS of 37%) to 0.843 to 0.844 (for RBTS of 85%). The PAs for FAW resistance with PBTS were generally high varying from 0.83 to 0.86, except for one dataset that had PAs ranging from 0.11 to 0.75. GP models showed generally similar predictive abilities for each trait while the TS designation was determinant. There was a highly positive correlation (R=0.92***) between TS size and PAs for the RBTS approach while, for the PBTS, these parameters were highly negatively correlated (R=-0.44***), indicating the importance of the degree of kinship between the TS and the BS with the smallest TS (31%) achieving the highest PAs (0.86). This study paves the way towards the use of GS for maize resistance to insect pests in sub-Saharan Africa.

Genomic selection (GS) can accelerate variety release by shortening the variety development phase when factors that influence prediction accuracies (PA) of genomic prediction (GP) models such as training set (TS) size and relationship with the breeding set (BS) are optimized beforehand. In this study, PAs for the resistance to fall armyworm (FAW) and maize weevil (MW) in a diverse tropical maize panel composed of 341 double haploid and inbred lines were estimated using 16 parametric, semi-parametric, and nonparametric algorithms with a 10-fold and 5 repetitions cross-validation strategy. For MW resistance, 126 lines that had both genotypic and phenotypic data were used as a TS (37% of the panel) and the remaining lines, with only genotypic data, as a BS. Regarding FAW damage resistance, two TS determination strategies, namely: random-based TS (RBTS) with increasing sizes (37, 63, 75, and 85%) and pedigree-based TS (PBTS) were used. For both MW and FAW resistance datasets with an RBTS of 37%, PAs achieved with phenotypic best linear unbiased predictors were at least as twice as higher than those realized with best linear unbiased estimators. The PAs achieved with BLUPs for MW resistance traits varied from 0.66 to 0.82. The PAs with BLUPs for FAW resistance datasets ranged from 0.694 to 0.714 for RBTS of 37%, and 0.843 to 0.844 for RBTS of 85%. The PAs with BLUPs for FAW resistance with PBTS were generally high varying from 0.83 to 0.86, except for the third dataset which had the largest TS (86.22% of the panel) with PAs ranging from 0.11 to 0.75. GP models showed generally similar predictive abilities for each trait while the TS designation was determinant. There was a highly positive correlation (R=0.92***) between TS size and PAs for the RBTS approach while, for the PBTS, these parameters were highly negatively correlated (R=-0.44***), indicating the importance of the relationship between the TS and the BS with the smallest TS (31%) achieving the highest PAs (0.86). This study paves the way towards the use of GS for maize resistance to insect pests in sub-Saharan Africa.

Africa has been here before! The human immunodeficiency virus (HIV) epidemic ravaged across most of the continent. Then, the regional outbreaks of the very transmissible and fatal Ebola virus. Now,...

Purpose: Risk stratification and molecular targeting have been key to increasing cure rates for pediatric cancers in high-income countries. Precise diagnosis and successful treatment of pediatric cancer in low-resourced settings is often hindered by insufficient pathology infrastructure, including lack of laboratory platforms for molecular analysis. Given the high frequency of gene fusions in pediatric cancers, identifying such fusions would greatly aid cost-effective pediatric cancer diagnosis, risk stratification, and precision medicine in low-resourced settings. Methods: To allow for implementation of gene fusion detection at Global HOPE sites in Sub-Saharan Africa (SSA), methodologies were reviewed to consider minimal technical expertise required, the ability to utilize samples with sub-optimal RNA quality, and rapid turn-around-time. Literature review, clinical laboratory results, public databases, and large-scale genomic studies were used to obtain exact breakpoint sequence information for gene fusions associated with pediatric and adolescent cancers. Results: Two custom pediatric gene fusions panels were designed using the NanoString Elements technology. The hematologic malignancy panel was designed to detect 439 breakpoints for 223 non-IGH/TCR fusions reported in ALL, AML, lymphomas, and histiocytosis. The solid tumor panel was designed to detect 204 breakpoints for 436 fusions associated with pediatric sarcomas, brain tumors, and renal malignancies. Each panel was tested using 96 samples with known fusion status at Texas Children's Hospital to determine specificity, sensitivity, precision, and ease of workflow. Conclusions: The design, testing, and implementation of a rapid assay to detect gene fusions with diagnostic, prognostic, and therapeutic impact would be transformational in the care of pediatric cancer patients in low-resourced settings. The custom designed panels will allow for large-scale fusion detection in 2-3 days with only 15 minutes of technician time after RNA isolation. Additional steps are needed to identify and address any challenges upon initiation in SSA to fully realize the potential of such technology. Citation Format: Julie Gastier-Foster, Fredrick Lutwama, Joseph Lubega, Kevin Fisher, Dolores Lopez-Terrada, Angshumoy Roy, Nmazuo Ozuah, Jeremy Slone, Peter Wasswa, Carl Allen, David Poplack. Custom Gene Fusion Assays for the Rapid Diagnosis of Pediatric Cancers in Low-Resourced Settings [abstract]. In: Proceedings of the 9th Annual Symposium on Global Cancer Research; Global Cancer Research and Control: Looking Back and Charting a Path Forward; 2021 Mar 10-11. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2021;30(7 Suppl):Abstract nr 98.

PURPOSE: Lymphoma is the commonest pediatric cancer in sub-Saharan Africa (SSA). Frequent treatment abandonment contributes to suboptimal outcomes. We examined risk factors and reasons for treatment abandonment for this population in Malawi. METHODS: We conducted a mixed methods study among children

Point-of-care tools are needed in sub-Saharan Africa (SSA) to improve pediatric Burkitt lymphoma (BL) diagnosis and treatment. We evaluated plasma Epstein-Barr virus (pEBV) DNA as a pediatric BL biomarker in Malawi. Prospectively enrolled children with BL were compared to classical Hodgkin lymphoma (cHL) and nonlymphoma diagnoses. Pediatric BL patients received standardized chemotherapy and supportive care. pEBV DNA was measured at baseline, mid-treatment, and treatment completion. Of 121 assessed children, pEBV DNA was detected in 76/88 (86%) with BL, 16/17 (94%) with cHL, and 2/16 (12%) with nonlymphoma, with proportions higher in BL versus nonlymphoma (p

In sub Saharan Africa, past effort has registered success in developing high yielding and foliar disease resistant maize (Zea mays L.) varieties, which are deficient in pro-vitamin A. A new initiative is to develop maize varieties, tolerant to foliar diseases and rich in pro-vitamin A carotenoids. To achieve this, yellow conversions of white testers and other elite maize varieties have been developed by the International Center for Maize and Wheat Development (CIMMYT). Unlike the white lines, limited information on agronomic performance and disease resistance is available for yellow maize conversions. This study was conducted to evaluate the performance of white maize and their corresponding yellow maize conversions for yield and tolerance to Maize streak virus (MSV) disease; and determine the inheritance patterns of these traits. Fourty seven three-way hybrids generated in a Line by tester mating design (North Carolina 2), 12 inbred lines (used as male parents), 4 single crosses (used as female parents) and 3 commercials checks were screened for resistance to Maize streak virus (MSV) disease at the National Crop Resources Research Institute (NaCRRI) in Uganda. The same genotypes were evaluated in a 9x5 alpha lattice design in three locations of Uganda (National Crop Resources Research Institute (NACRRI), National Semi Arid Resources Research Institute (NaSARRI) and Bulambuli) for agronomic performance. Results confirmed tolerance to MSV in testers CML202, CML395, CML444, CML445 and CML312-SR (white). Genotypes performed significantly differently for yield, anthesis days, plant height, ear height, husk cover, grain texture, reaction to Gray leaf spot (GLS) (P0.05) in agronomic performance and tolerance to diseases. General combining ability (GCA) was more important than specific combining ability (SCA) for most traits, except for anthesis days, Turcicum leaf blight (TLB), GLS and yield. GCA effects for yield were not significant in both lines (male parents) and single cross testers (female parents) of white and yellow conversions. However, two unique cases were observed for diseases; yellow conversion of line CML444 significantly combined for susceptibility to TLB; while tester CML312/CML442 combined for resistance to GLS. Additionally, there was low heritably estimates for tolerance to MSV and yield. Generally, there was no significant difference between white and corresponding yellow maize conversion, implying that there is no significant loss in MSV resistance and yield performance while converting white into yellow maize.Key words: Combining ability, pro-vitamin A, Zea mays L.

The cassava breeding program in Uganda has released many improved cultivars resistant/tolerant to cassava brown streak disease (CBSD) and cassava mosaic disease (CMD). However, many farmers have continued to use cultivars that are susceptible to these major viral diseases but with diverse attributes. There is a need to understand farmers’ cassava cultivar attribute preferences and CBSD, CMD prevalence on the preferred cultivars. A total of 150 cassava farmer fields (74 in Bukedea district and 76 in Kumi district) located in eastern Uganda were evaluated for farmers’ cultivars and attribute preferences, as well as prevalence of CBSD and CMD on the farmer selected cultivars. The eastern region was of interest in the study, due to it-being the major cassava producing area in the country. In addition, 30 cassava plants of different genotypes were chosen randomly along transects of each field and assessed for CBSD/CMD incidence and severity on preferred cultivars. Results showed that more than 64% of the farmers in eastern Uganda preferred NASE 03 due to its sweet taste and high yields, followed by NASE 14 (21%) because of its high yields. There was a significant (P≤0.001) correlation between cassava cultivars preferred and CBSD severity (r = -0.56), CBSD incidence (r = -0.53), CMD severity (r = -0.51) and CMD incidence (r = -0.39). In corroboration, the most preferred cultivar, NASE 03 was found most susceptible to CBSD and CMD in both Bukedea and Kumi districts with CBSD incidence of 62.2% and 52.7% and CMD incidence of 56.9% and 34.3% respectively. The results showed that CBSD and CMD are prevalent on farmer preferred cassava cultivars, and that farmer cultivar preference depends not only on disease resistance but also other attributes.

Millions of children continue to miss immunizations each year despite global increases in financing and advances in vaccine technology. Male involvement in routine child immunization activities could improve and sustain coverage but is rarely emphasized in immunization programs or research. This study identified factors associated with male involvement in routine child immunization using the attitude, social influence and self-efficacy model.A household cluster survey was conducted among 460 fathers aged 18 years or more, with children aged 10-23 months. A semi-structured interviewer-administered questionnaire was used to collect data. Prevalence Risk Ratios (PRRs) were used to measure associations with level of involvement using generalized linear models with Poisson family, log link and robust standard errors in STATA 12. Our findings show that half (51%, 236/460) of the respondents were aged 25-34 years; 36% (166/460) had completed eight or more years of formal education. Although90% (415/460) of the respondents were willing to be involved, only 29% (133/460) were highly involved in routine child immunization. Highly involved fathers had a positive attitude towards involvement in routine child immunization (adj. PRR 2.3, 95% CI 1.18 – 4.98) and were ≥45 years adjusted prevalence risk ratio (adj. PRR) 2.0, 95% confidence interval (CI) 1.15 - 3.76. Traders had a lower involvement compared to those engaged in other occupations (adj. PRR 0.55, 95% CI: 0.37 - 0.82). In conclusion, few fathers were involved in routine child immunization. Strategies to improve fathers’ positive attitude such as health education are needed to increase their involvement, specifically targeting younger fathers and traders.

PURPOSE Specialized multidisciplinary care is central to childhood cancer control. Expertise and infrastructure in the pediatric disciplines of hematology, surgery, critical care, nursing, and pathology are as critical as pediatric oncology. Survival of the majority of children with cancer globally remains dismal because of the scarcity of multidisciplinary pediatric subspecialty services. We present the innovative approach and impact of Texas Children’s Global HOPE initiatives to cost-effectively develop capacity for specialized multidisciplinary cancer care for children in sub-Sahara Africa (SSA). METHODS Global HOPE designed and supports subspecialty training and contingent infrastructure building in SSA in the following disciplines that are critical to pediatric cancer care: pediatric hematology and oncology (PHO), pediatric surgery, pediatric critical care, anatomic and molecular pathology, and pediatric oncology nursing. Key principles underlying the design of each disciplinary program are that it enables the implementation of current best evidence-based practices, primarily uses a problem-based learning approach, and is integrated and accredited by the local health sciences university. Training primarily occurs at an African hub where Global HOPE also supports infrastructure for clinical care and research, in addition to onsite faculty and offsite telemedicine support from the headquarters in Houston, TX. RESULTS The PHO and pediatric surgery fellowship programs based at Makerere University, Kampala, are the most advanced thus far. Twenty pediatricians from 6 African countries have enrolled and 8 have graduated from the 2-year PHO program. One surgeon enrolled in the 3-year pediatric surgery fellowship annually and 6 have graduated since inception. The fellowship programs have directly affected patient outcomes because of evidence-based clinical rigor and enhanced clinical infrastructure. All graduates from the 2 fellowships are currently practicing in SSA. CONCLUSION Formal in situ pediatric subspecialty training is feasible in low- and middle-income countries and carries the critical advantages of infrastructure development, direct patient impact, and is less susceptible to brain drain.