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Introduction A proportion of people develop Long Covid after acute COVID-19, but with most studies concentrated in high-income countries (HICs), the global burden is largely unknown. Our study aims to characterise long-term COVID-19 sequelae in populations globally and compare the prevalence of reported symptoms in HICs and low-income and middle-income countries (LMICs).Methods A prospective, observational study in 17 countries in Africa, Asia, Europe and South America, including adults with confirmed COVID-19 assessed at 2 to

Abstract Background Using a desirable tester is considered one method used to maximise genetic differences among test crosses derived from new inbred lines and improves the overall performance of maize. Thus, this study aimed to evaluate the potency of the tester with varying levels of resistance to Striga hermonthica in determining the testcross performance of the hybrids for Striga resistance and yield-related traits. Method The experiment was conducted with these test crosses and two standard checks (susceptible and tolerant) for different Striga resistance and agronomic traits during the 2018 cropping season in Abuja and Mokwa, Nigeria. The experiment was laid out in a 23 × 4 alpha-lattice design with two replications in each location. Field evaluation data was collected from Striga resistance and yield-related traits to estimate the performance of test crosses. Analysis of variance was conducted to determine the variance of the testcross performance. Results There were significant differences among test crosses for days to silking, days to pollen shedding, ear at harvest, ear aspect, ear per plant, grain yield, Striga damage rating at 8 and 10 weeks after planting (WAP), and Striga count at 8 and 10 WAP. Variations among test crosses were always higher than the corresponding variations due to the interaction between test crosses and the environment for all traits. Conclusion The inbred lines with low yield reduction crossed with different testers under Striga infested were recorded. These inbreds should be used to develop high-yielding hybrids and synthetics with elevated levels of Striga resistance to improve the maize breeding program.

Biofortification of provitamin A in maize is an attractive and sustainable remedy to the problem of vitamin A deficiency in developing countries. The utilization of molecular markers represents a promising avenue to facilitate the development of provitamin A (PVA)-enriched maize varieties. We screened 752 diverse tropical yellow/orange maize lines using kompetitive allele-specific PCR (KASP) makers to validate the use of KASP markers in PVA maize breeding. To this end, a total of 161 yellow/orange inbred lines, selected from among the 752 lines, were evaluated for their endosperm PVA and other carotenoid compounds levels in two separate trials composed of 63 and 98 inbred lines in 2020 and 2021, respectively. Significant differences (p < 0.001) were observed among the yellow maize inbred lines studied for all carotenoid profiles. An inbred line TZMI1017, introduced by the International Institute of Tropical Agriculture (IITA) showed the highest level of PVA (12.99 µg/g) and β-carotene (12.08 µg/g). The molecular screening showed 43 yellow maize inbred lines carrying at least three of the favorable alleles of the KASP markers. TZMI1017 inbred line also carried the favorable alleles of almost all markers. In addition, nine locally developed inbred lines had medium to high PVA concentrations varying from 5.11 µg/g to 10.76 µg/g and harbored the favorable alleles of all the KASP PVA markers. Association analysis between molecular markers and PVA content variation in the yellow/orange maize inbred lines did not reveal a significant, predictable correlation. Further investigation is warranted to elucidate the underlying genetic architecture of the PVA content in this germplasm. However, we recommend strategic utilization of the maize-inbred lines with higher PVA content to enhance the PVA profile of the breeding program’s germplasm.

Abstract Drought represents a significant production challenge to maize farmers in West and Central Africa, causing substantial economic losses. Breeders at the International Institute of Tropical Agriculture have therefore been developing drought‐tolerant maize varieties to attain high grain yields in rainfed maize production zones. The present review provides a historical overview of the approaches used and progress made in developing drought‐tolerant hybrids over the years. Breeders made a shift from a wide area testing approach, to the use of managed screening sites, to precisely control the intensity, and timing of drought stress for developing drought‐tolerant maize varieties. These sites coupled with the use of molecular markers allowed choosing suitable donors with drought‐adaptive alleles for integration into existing elite maize lines to generate new drought‐tolerant inbred lines. These elite maize inbred lines have then been used to develop hybrids with enhanced tolerance to drought. Genetic gains estimates were made using performance data of drought‐tolerant maize hybrids evaluated in regional trials for 11 years under managed drought stress, well‐watered conditions, and across diverse rainfed environments. The results found significant linear annual yield gains of 32.72 kg ha−1 under managed drought stress, 38.29 kg ha−1 under well‐watered conditions, and 66.57 kg ha−1 across multiple rainfed field environments. Promising hybrids that deliver high grain yields were also identified for areas affected by drought and variable rainfed growing conditions. The significant genetic correlations found among the three growing conditions highlight the potential to exploit the available genetic resources and modern tools to further enhance tolerance to drought in hybrids.

Soil-transmitted helminth (STH) infections are among the most common infections that affect the poorest and most deprived communities. In most developing countries, children aged 5 to 15 years are at risk for chronic helminth infection and associated morbidity. This study aimed to determine the prevalence of STH infections and associated risk factors among three government elementary schools in Dembecha town, Ethiopia. We conducted a school-based cross-sectional study involving 316 participants between November 2019 and March 2020. A systematic random sampling method was used to select study participants from the study schools. Data related to the sociodemographic characteristics of the study participants and risk factors for STH infections were collected using a pretested questionnaire survey. Parasitological examinations of stool samples were performed using the formal-ether concentration method. Study participants aged 5 to 15 years were enrolled in this study. The overall prevalence of STH infection was 21.5% (68/316). Ascaris lumbricoides ranked highest, with a prevalence of 11.4%, followed by hookworms 7.3%, Trichuris trichiura 1.9%, and Strongloides stercoralis 0.9%. Age groups of 10-15 years (AOR =3.109; 95% CI: 1.033, 9.350), residence in Kebele 2 (AOR =2.990; 95% CI: 1.082, 8.264), illiterate mothers (AOR =4.689; 95% CI: 1.410, 15.59), and a family size of 4-6 (AOR =3.286; 95% CI: 1.299, 8.313) were significantly associated with STH infections. The prevalence of STH infections remains an important health issue for study participants. Therefore, school deworming programs twice a year are crucially needed until the prevalence falls below the level of public health importance.

Abstract Background The establishment of heterotic groups of inbred lines is crucial for hybrid maize breeding programs. Currently, there is no information on the heterotic patterns of the Provitamin A (PVA) inbred lines developed in the maize improvement program of the International Institute of Tropical Agriculture (IITA) to form productive PVA enriched hybrids for areas affected by vitamin A deficiency. This study assessed the feasibility of classifying PVA-enriched inbred lines into heterotic groups based on PVA content without compromising grain yield in hybrids. Sixty PVA inbred lines were crossed to two testers representing two existing heterotic groups. The resulting 120 testcrosses hybrids were evaluated for two years at four locations in Nigeria. Results The two testers effectively classified the inbred lines into two heterotic groups. The PVA-based general combining ability and specific combining ability (HSGCA) method assigned 31 and 27 PVA enriched maize inbred lines into HGB and HGA, respectively, leaving two inbred lines not assigned to any group. The yield-based HSGCA method classified 32 inbred lines into HGB and 28 inbred lines into HGA. Both PVA and yield-based heterotic grouping methods assigned more than 40% of the inbred lines into the same heterotic groups. Even though both PVA and yield-based heterotic grouping of the inbred lines differed from the clusters defined by the DArTag SNP markers, more than 40% of the inbred lines assigned to HGA were present in Cluster-1 and 60% of the inbred lines assigned to HGB were present in Cluster-3. Interestingly, the inbred lines assigned to the same heterotic groups based on PVA content and grain yield were distributed across the three Ward’s clusters. The PVA-based HSGCA was identified as the most effective heterotic grouping method for breeding programs working on PVA biofortification. Conclusions Selecting PVA enriched maize inbred lines with diverse genetic backgrounds from the three marker-based clusters may facilitate the development of productive hybrids with high PVA content and for generating source populations to develop more vigorous maize inbred lines with much higher concentrations of PVA.

Abstract Understanding the genetic relationships between the key founder inbred lines and derived inbred lines could provide insight into the breeding history and the structure of genetic diversity of the available elite inbred lines with desirable target traits. The maize improvement program at the International Institute of Tropical Agriculture (IITA) analyzed the pedigree information of 623 sub-tropical maize inbred lines generated at the IITA maize breeding program to identify the key founder inbred lines. We also used 5032 SNP markers to assess the genetic similarities of the founder inbred lines with their progenies subsequently developed for specific target traits. The results of pedigree analysis and SNP markers-based similarity scores identified 20 key founder inbred lines with significant contributions to the development of drought tolerant, early maturing, productive, Striga resistant, provitamin A enriched, and quality protein maize inbred lines. In our breeding program, line TZMi501 belonging to a flint heterotic group (HGA), and TZMi407-S and TZMi214, representing the dent heterotic group (HGB), were identified as the most useful founder inbred lines. The 623 inbred lines were consistently separated into four clusters based on Ward’s hierarchical clustering, structure, and principal component analyses, with the 20 founder inbred lines spread into all clusters. The founder inbred lines were more genetically related to the productive inbred lines but showed genetic divergence from the provitamin A enriched inbred lines. These results provide a better understanding of the breeding history of the sub-tropical maize inbred lines to facilitate parental selection aligned to existing heterotic groups for use in breeding programs targeting the improvement of essential traits in maize.

This review assesses the book titled "The instructional design knowledge base: Theory, research, and practice" authored by Richey, Klein, and Tracy, highlighting its emphasis on foundational knowledge, extensive theory base, and application to current Instructional Design (ID) practices. The book offers a comprehensive overview of ID theories from various disciplines, making it valuable for scholars, graduate students, educators, and practitioners in the field. It also guides decision-making and includes suggestions for future research, making it beneficial for researchers aiming to contribute to the field of ID.

Simultaneous occurrences of heat and drought stresses have a detrimental effect on growth, development and yield of maize. Heat and drought is expected to worsen maize yield losses under climate change. Selecting CDHS tolerant maize hybrids creates great opportunity for sustainable maize improvement in the tropics. The objective of current investigation was to dissect the genetic basis of CDHS tolerance in tropical maize and to determine performance of single cross hybrids under CDHS. Ninety six single-cross hybrids resulted from crossing 12 tassel blast tolerant and 12 tassel blast susceptible lines along with two Striga resistant commercial hybrids, a heat tolerant and a heat susceptible check hybrids were evaluated under FIRR, MDRTS and CDHS using 25x4 alpha lattice design with two replications. The results showed significant genetic variation for FIRR, MDRTS and CDHS tolerance among maize hybrids. The majority of single crosses that showed improved grain yield over their respective standard checks under MDRTS also exhibited improved grain yield over the same checks under CHDS, indicating development of CHDS tolerance hybrids. Significant and positive genotypic and phenotypic correlation of grain yield under MDRTS and CDHS implicated common genetic mechanisms controlling yield under MDRTS and CDHS. Stress tolerance indices YI, GMP, MP, HM and STI were identified as best selecting indices under both stresses. GCA variances were larger than SCA variances in each testing environment for most studied traits indicating the impotence of additive gene action than non-additive gene action to control these traits. Majority of stress indices and SCA effects demonstrated that hybrids HB18, HB41, HB91 and HB95 were high yielder under MDRTS and CDHS. Hybrids HB41, HB91 and HB95 and their parents' scored minimum tassel blast. Parents 19 and 7 were well general combiner for grain yield and early maturity under MDRTS and CDHS indicting their valuable source of genes for hybridization. The current findings revealed that CDHS tolerance hybrids can reduce expected yield losses and maintain maize productivity in CDHS prone areas. Promising hybrids should be tested further under various drought and CHDS for commercialization.

Maize is an important food and industrial cereal crop that serves as the main source of energy for millions of low-income people in sub-Saharan Africa (SSA), but its production and productivity are constrained by many constraints, among which the fall armyworm (FAW) is the major one. The use of insecticides is the most effective control measure for the FAW. However, excessive use of chemical insecticides has environmental and health implications, and it can be expensive for resource-poor farmers. The objective of this study was to evaluate the extent of variation in yield losses due to the FAW among some elite maize open-pollinated varieties (OPVs) under two levels of insecticide application and control (0 application). In a two-year field study, 10 elite maize OPVs were evaluated under two levels of emamectin benzoate (5% WDG) applications and the control: 75 and 150 mL of spray solution per 20 L of water. The experimental design was a randomized complete block with three replications. The data were collected on grain yield (GY) and FAW leaf damage rating (LDR). The LDR was conducted on a 1–9 scale and used to categorize the maize varieties as resistant (1–4), moderately resistant (4–6), and susceptible (6–9). Significant varietal differences were obtained for GY and LDRs. The GY of the varieties under control (0 mL), 75 and 150 mL insecticide applications ranged from 3.3 t ha−1 (DTSTR-Y SYN-13) to 4.6 t ha−1 (PVA SYN-3), from 4.5 t ha−1 (DTSTR-Y SYN-13) to 6.4 t ha−1 (PVA SYN-13), and from 4.2 t ha−1 (DTSTR-Y SYN-13) to 6 t ha−1 (DTSTR-Y SYN-14), respectively. No significant differences in GY were found between the application of 75 and 150 mL of insecticide application. The relative loss in GY among the varieties under control (0 mL) differed with an increase in the level of insecticide application. The relative GY loss at the 75 mL insecticide application ranged from 18% (PVA SYN-3) to 38% (DTSTR-Y SYN-15) with a mean of 27%, whereas at the 150 mL insecticide application, it varied from 13% (PVA SYN-3) to 42% (DTSTR-Y SYN-15), with a mean of 26%. All the varieties exhibited moderate resistance to FAW, except DTSTR-Y SYN-14, which was susceptible. The varieties PVA SYN-3 and PVA SYN-13 were the most consistent in GY across the three insecticide treatment levels. The mean performance of the varieties for FAW leaf damage ranged from 4.0 (SAMMAZ-15) to 6.2 (DTSTR-Y SYN-14), from 4.5 (SAMMAZ-15) to 6.3 (PVA SYN-6), from 4.5 (SAMMAZ-15) to 6.3 (DTSTR-Y SYN-14), and from 3.5 (SAMMAZ-15) to 5 (DTSTR-Y SYN-14) for LDR 1, LDR 2, LDR 3, and LDR 4, respectively. The use of moderately resistant varieties, combined with timely spraying of emamectin benzoate at 75 mL provided adequate management for the FAW infestation and sustained high maize grain yield.

Micronutrient deficiencies are pervasive in the diets of millions of people in developing countries, calling for effective mitigation measures. The development of biofortified cultivars through breeding holds promise for sustainable and affordable solutions to combat micronutrient deficiencies. Breeding efforts in the past decade have resulted in dozens of biofortified open-pollinated varieties and hybrids adapted to diverse agroecological zones. Advances in genomics and molecular tools enabled rapid identification of maize cultivars enriched with essential micronutrients such as pro vitamin A (PVA), iron (Fe), and zinc (Zn). Leveraging Multi-omics-driven discovery of the genetic factors underlying the vast array of nutritional traits is paramount to mainstreaming breeding for quality traits in the product profile. Molecular breeding schemes, and integrating emerging Omics tools at every stage of the breeding pipeline, are vital to enhancing genetic gain. The recent momentum in elucidating the metabolism of micronutrients should be expanded to novel breeding targets as well as to the simultaneous enhancement of nutritional qualities while curtailing anti-nutritional factors in staple food crops. Harnessing new technologies to establish comprehensive and integrated breeding approaches involving nutrigenomics, genome editing, and agronomic biofortification is crucial in tackling nutritional insecurity. This review highlights the prospect of integrating modern tools in hastening the genetic improvement of nutritionally enriched maize.

Frequent occurrence of drought, heat, low soil fertility and Striga infestation are the main stress factors reducing maize yield in the Sahel. Adoption of stable multiple stress tolerant maize cultivars in the region is crucial for achieving food security. However, selection of a stable high yielding cultivar is complicated by genotype × environment interaction (GEI) due to differential responses to growing conditions. Eleven extra-early maturing multiple-stress tolerant maize hybrids and two checks arranged in a randomized complete block design was evaluated across nine locations for two years in Mali and Niger. The objectives of this study were to identify (i) stable and high-yielding maize hybrids, and (ii) suitable test locations for selecting promising extra-early maize hybrids. GGE biplot was used for graphical analysis. Significant genotype, location and GEI effects were detected for grain yield and number of ears per plant. EEWQH-13 produced the highest grain yield (3860 kg ha−1) while EEYQH-1 had the poorest yield (2663 kg ha−1) with trial mean of 3395 kg ha−1 for all hybrids. GGE biplot explained 69.6 % of the total variation in grain yield among the hybrids. The polygon view identified EEWQH-13 as the best hybrid across six of the nine test locations. EEPVAH-58 was identified as the most stable high yielding hybrid across the nine test locations followed by EEWQH-16 and EEWQH-13. The nine locations were clustered under two mega-environments (ME1, ME2). Among the nine test locations, Tara and Aderaoua clustered in ME1 were the most suitable ones for selecting promising extra-early maize hybrids for wider adaptation. The three hybrids, EEPVAH-58, EEWQH-16, and EEWQH-13, identified in this study could be recommended for on-farm evaluation to confirm the consistency of their yield performance for possible release and commercialization in Mali and Niger.

Abstracts Background Tele-pharmacy is a subset of telemedicine in which pharmacies use telecommunication technology to provide patient care. Tele-pharmacy can improve pharmaceutical care service delivery by reducing medication errors, improving access to health professionals and facilities in remote and rural areas, and minimizing adverse drug events. However, there is limited evidence regarding future pharmacists' knowledge and perceptions of the Tele-pharmacy system in Ethiopia. As a result, this study aimed to assess tele-Pharmacy perception, knowledge and associated factors among pharmacy students in Northwest Ethiopia. Methods An institutional-based cross-sectional study was conducted among 376 pharmacy students in Northwest Ethiopia between July 15 and August 27, 2022. A pre-tested self-administered questionnaire was used to collect data. The data were entered using Epi info version 7.0 and analyzed using SPSS version 25. Descriptive statistics, bivariable and multivariable logistic regression analysis were used to describe pharmacy students' knowledge and perceptions of Tele-pharmacy and identify associated factors. An adjusted odds ratio (OR) and a p-value with a 95% confidence interval (CI) were calculated to declare statistical significance. Results From a total of 352 participants, about 32.4% with [95% CI (27%-37%)] and 48.6% with [95% CI (43%—54%)] had good knowledge and a positive perception toward Tele-pharmacy, respectively. Being age group of 26–30 (AOR = 0.35, 95% CI: 0.17–0.68), being male (AOR = 2.38, 95% CI: 1.26–4.49), Having a CPGA of > 3.5 (AOR = 2.28, 95% CI: 1.24–4.19), Taking basic computer training (AOR = 2.00, 95% CI: 1.17–3.39), Management support (AOR = 1.84, 95% CI: 1.06–3.19) were found to be significantly associated with pharmacy students' knowledge of Tele-pharmacy. Similarly, having access to electronic devices (AOR = 3.80, 95% CI: 1.81–7.97), training related to pharmacy information systems (AOR = 6.66, 95% CI: 3.34–13.29), availability of guidelines (AOR = 2.99, 95% CI: 1.62–5.50) were found to be significantly associated with pharmacy students' perceptions of Tele-pharmacy. Conclusion This study found that pharmacy students have limited knowledge and perceptions of the Tele-pharmacy system. A continuing Tele-pharmacy training package, incorporating pharmacy information system guidelines as part of their education, and providing managerial support could be recommended to improve pharmacy students' knowledge and perception of Tele-pharmacy.

This study investigated the effects of genotype, location, and planting season on the proximate composition and metabolizable energy of advanced maize hybrids. Twenty-five hybrid maize and a local variety as control were harvested from five locations 100 days after planting for two seasons. The maize samples were sorted, cleaned, and pulverized using a laboratory mill and were analyzed for nutritional composition and metabolizable energy (ME) using standard laboratory methods. Moisture content, ash, fat, and protein had mean ± SD of 8.97 ± 0.40%, 1.48 ± 0.05%, 4.31 ± 0.19, and 8.88 ± 0.18%, respectively. ME had a mean ± SD of 379.77 ± 2.17 kJ, and total carbohydrates had values ranging from 74.68 and 77.20%, with an average of 76.68%. Results showed that most of the variations expressed in the proximate compositions of the maize hybrids were not significantly (p > 0.05) dependent on the genotypes. In contrast, locations significantly affected the maize hybrids’ proximate composition and metabolizable energy (p < 0.001). In addition, there was no significant effect (p > 0.05) of location by genotype interaction on the proximate composition and ME of the maize samples. The planting season also exhibited a significant (p < 0.001) difference for all the proximate parameters. Fourteen out of the twenty-five maize hybrids were similar to the local variety in terms of proximate composition and metabolizable energy. Therefore, they could be recommended for advancement in the breeding stages for release for household and industrial uses.

Antiviral treatments for SARS-CoV-2 infection are only beneficial when used early in infection, so early case detection is important. Here, the authors assess the frequency of testing needed to achieve population-level benefits and demonstrate the importance of high coverage and short delays from test to treatment.

In sub-Saharan Africa (SSA), millions of people depend on maize as a primary staple. However, maize consumers in SSA may be exposed to malnutrition due to vitamin A deficiency (VAD) and unsafe aflatoxin levels, which can lead to serious economic and public health problems. Provitamin A (PVA) biofortified maize has been developed to alleviate VAD and may have additional benefits such as reduced aflatoxin contamination. In this study, maize inbred testers with contrasting PVA content in grain were used to identify inbred lines with desirable combining ability for breeding to enhance their level of resistance to aflatoxin. Kernels of 120 PVA hybrids generated by crossing 60 PVA inbreds with varying levels of PVA (5.4 to 51.7 µg/g) and two testers (low and high PVA, 14.4 and 25.0 µg/g, respectively) were inoculated with a highly toxigenic strain of Aspergillus flavus. Aflatoxin had a negative genetic correlation with β-carotene (r = −0.29, p < 0.0001) and PVA (r = −0.23, p < 0.0001), indicating that hybrids with high PVA content accumulated less aflatoxin than those with low to medium PVA. Both general combining ability (GCA) and specific combining ability (SCA) effects of lines and testers were significant for aflatoxin accumulation, number of spores, PVA, and other carotenoids, with additive gene actions playing a prominent role in regulating the mode of inheritance (GCA/SCA ratio >0.5). Eight inbreds had combined significant negative GCA effects for aflatoxin accumulation and spore count with significant positive GCA effects for PVA. Five testcrosses had combined significant negative SCA effects for aflatoxin with significant positive SCA effects for PVA. The high PVA tester had significant negative GCA effects for aflatoxin, lutein, β-carotene, and PVA. The study identified lines that can be used as parents to develop superior hybrids with high PVA and reduced aflatoxin accumulation. Overall, the results point out the importance of testers in maize breeding programs to develop materials that can contribute to controlling aflatoxin contamination and reducing VAD.

Abstract Background Temperate maize inbred lines with expired Plant Variety Protection Act certificates (Ex-PVP) are potential sources of desirable alleles for tropical germplasm improvement. Up to now, the usefulness of the Ex-PVP inbred lines as a potential source of novel beneficial alleles for Striga hermonthica resistance breeding to enhance genetic gain in tropical maize has not been reported. Results This study was thus conducted to characterize the combining ability of 24 Ex-PVP inbred lines in crosses with two tropical Striga resistant inbred testers under Striga-infested and non-infested conditions and across three locations for 2 years. Many testcrosses between Ex-PVP inbred lines and the first tester (T1) produced competitive or significantly higher grain yields compared to the hybrid between the two resistant testers under Striga infested and non-infested conditions and across multiple test locations. Also, most of the testcrosses with positive heterosis for grain yield and negative heterosis for Striga damage and emerged Striga count involved T1 as a tester. Our study identified six Ex-PVP inbred lines with positive GCA effects for grain yield under Striga infested and non-infested conditions and across multiple test locations. Amongst these, inbred lines HB8229-1 and WIL900-1 also displayed negative GCA effects for emerged Striga count and Striga damage rating. The inbred line HB8229-1 showed positive SCA effects for grain yield with T2, whereas WIL900-1 had positive SCA effects for grain yield with T1. Over 70% of the Ex-PVP inbred lines were consistently assigned to specific heterotic groups using yield-based classifying methods (mean grain yield and SCA effects). Conclusions These results could facilitate systematic introgression of the Ex-PVP inbred lines into the existing Striga resistant heterotic groups in IITA. The Ex-PVP inbred lines with positive GCA effects and producing high grain yields in hybrid combinations could be useful parents for enhancing Striga resistance and agronomic performance of tropical maize hybrids.

We analyze the risk attitude of women and men entrepreneurs in the micro and small enterprises (MSEs) and investigate the factors that influence the risk attitude of MSE owners. The empirical analysis of the study consists of two parts. First, we use a moment-based approach to estimate the risk preferences of male and female entrepreneurs. Second, we estimate a regression model to understand the correlates of risk attitude and decompose the gender difference in risk aversion using the Oaxaca-Blinder technique. The results indicate that MSE entrepreneurs are risk-averse, with a relative risk premium of 1.5%. We also find that females are slightly more risk-averse than male entrepreneurs. Our regression estimates show that entrepreneurs' risk attitude is significantly correlated with the age and experience of the entrepreneur, marital status, education level and financial literacy, wealth, sector, and business form. Furthermore, the predictor variables significantly explain the gender difference in risk aversion, while the unexplained component is insignificant. This suggests that the gender difference in risk aversion is due to disparities in socioeconomic factors than a biological difference in risk preference. [ABSTRACT FROM AUTHOR]

Abstract This study analyzes the impact of a component of climate‐smart agriculture (CSA) technology—Striga‐resistant maize (SRM) varieties and mineral fertilizer—on maize yield and food security using two rounds of panel data in Ghana. The study employs a multinomial endogenous switching regression model and finds that joint adoption of SRM varieties and mineral fertilizer increased maize yield by 872 kg/ha, food consumption scores by 17, and consumption per adult equivalent unit by 38 kg/ha. The positive impact of maize yield is high among adopters of multiple CSA technologies. The result is robust to an alternative endogeneity‐correcting model and the implications of the findings are discussed.

Abstract Striga hermonthica is a widespread, destructive parasitic plant that causes substantial yield loss to maize productivity in sub-Saharan Africa. Under severe Striga infestation, yield losses can range from 60 to 100% resulting in abandonment of farmers’ lands. Diverse methods have been proposed for Striga management; however, host plant resistance is considered the most effective and affordable to small-scale famers. Thus, conducting a genome-wide association study to identify quantitative trait nucleotides controlling S. hermonthica resistance and mining of relevant candidate genes will expedite the improvement of Striga resistance breeding through marker-assisted breeding. For this study, 150 diverse maize inbred lines were evaluated under Striga infested and non-infested conditions for two years and genotyped using the genotyping-by-sequencing platform. Heritability estimates of Striga damage ratings, emerged Striga plants and grain yield, hereafter referred to as Striga resistance-related traits, were high under Striga infested condition. The mixed linear model (MLM) identified thirty SNPs associated with the three Striga resistance-related traits based on the multi-locus approaches (mrMLM, FASTmrMLM, FASTmrEMMA and pLARmEB). These SNPs explained up to 14% of the total phenotypic variation. Under non-infested condition, four SNPs were associated with grain yield, and these SNPs explained up to 17% of the total phenotypic variation. Gene annotation of significant SNPs identified candidate genes (Leucine-rich repeats, putative disease resistance protein and VQ proteins) with functions related to plant growth, development, and defense mechanisms. The marker-effect prediction was able to identify alleles responsible for predicting high yield and low Striga damage rating in the breeding panel. This study provides valuable insight for marker validation and deployment for Striga resistance breeding in maize.

Maize is a strategic food crop in sub-Saharan Africa. However, most maize growing tropical savannas particularly in West and Central African experience the occurrence of frequent droughts and Striga infestation, resulting in 30–100% yield losses. This production zones need maize cultivars that combine tolerance to the two stresses. IITA in collaboration with national partners has thus employed a sequential selection scheme to incorporate both drought tolerance and Striga resistance in topical maize hybrids using reliable screening protocols. The main objective of the present study was therefore to use grain yield and other agronomic traits recorded in regional collaborative hybrid trials conducted for 8 years under manged stressful and non-stressful conditions and across rainfed field environments to estimate genetic gains in grain yields using mixed model analyses. The results showed significant (p < 0.05) annual yield gains of 11.89 kg ha−1 under manged drought stress (MDS) and 86.60 kg ha−1 under Striga infestation (STRIN) with concomitant yield increases of 62.65 kg ha−1 under full irrigation (WW), 102.44 kg ha−1 under Striga non-infested (STRNO) conditions and 53.11 kg ha−1 across rainfed field environments. Grain yield displayed significant but not strong genetic correlation of 0.41 ± 0.07 between MDS and STRIN, indicating that gene expression was not consistent across the two stress conditions. Furthermore, grain yield recorded in MET had significant moderate genetic correlations of 0.58 ± 0.06 and 0.44 ± 0.07It with MDS and STRIN, respectively. These results emphasize the need to screen inbred linens under both stress conditions to further enhance the rate of genetic gain in grain yield in hybrids for areas where the two stresses co-occur. Nonetheless, this study demonstrated that the sequential selection scheme has been successful in generating hybrids with dependable yields that can reduce chronic food deficits in rural communities experiencing simultaneous presence of drought and S. hermonthica infestation in their production fields.

Abstract Most of the maize (Zea mays L.) varieties in developing countries have low content of micronutrients including vitamin A. As a result, people who are largely dependent on cereal-based diets suffer from health challenges due to micronutrient deficiencies. Marker assisted recurrent selection (MARS), which increases the frequency of favorable alleles with advances in selection cycle, could be used to enhance the provitamin A (PVA) content of maize. This study was carried out to determine changes in levels of PVA carotenoids and genetic diversity in two maize synthetics that were subjected to two cycles of MARS. The two populations, known as HGA and HGB, and their advanced selection cycles (C1 and C2) were evaluated at Ibadan in Nigeria. Selection increased the concentrations of β-carotene, PVA and total carotenoids across cycles in HGA, while in HGB only α-carotene increased with advances in selection cycle. β-cryptoxanthine increased at C1 but decreased at C2 in HGB. The levels of β-carotene, PVA, and total carotenoids increased by 40%, 30% and 36% respectively, in HGA after two cycles of selection. α-carotene and β-cryptoxanthine content improved by 20% and 5%, respectively after two cycles of selection in HGB. MARS caused changes in genetic diversity over selection cycles. Number of effective alleles and observed heterozygosity decreased with selection cycles, while expected heterozygosity increased at C1 and decreased at C2 in HGA. In HGB, number of effective alleles, observed and expected heterozygosity increased at C1 and decreased at C2. In both populations, fixation index increased after two cycle of selections. The greatest part of the genetic variability resides within the population accounting for 86% of the total genetic variance. In general, MARS effectively improved PVA carotenoid content. However, genetic diversity in the two synthetics declined after two cycles of selection.

Background: Molecular breeding is an essential tool for accelerating genetic gain in crop improvement towards meeting the need to feed an ever-growing world population. Establishing low-cost, flexible genotyping platforms in small, public and regional laboratories can stimulate the application of molecular breeding in developing countries. These laboratories can serve plant breeding projects requiring low- to medium-density markers for marker-assisted selection (MAS) and quality control (QC) activities. Methods: We performed two QC and MAS experiments consisting of 637 maize lines, using an optimised genotyping workflow involving an in-house competitive allele-specific PCR (KASP) genotyping system with an optimised sample collection, preparation, and DNA extraction and quantitation process. A smaller volume of leaf-disc size plant samples was collected directly in 96-well plates for DNA extraction, using a slightly modified CTAB-based DArT DNA extraction protocol. DNA quality and quantity analyses were performed using a microplate reader, and the KASP genotyping and data analysis was performed in our laboratory. Results: Applying the optimized genotyping workflow expedited the QC and MAS experiments from over five weeks (when outsourcing) to two weeks and eliminated the shipping cost. Using a set of 28 KASP single nucleotide polymorphisms (SNPs) validated for maize, the QC experiment revealed the genetic identity of four maize varieties taken from five seed sources. Another set of 10 KASP SNPs was sufficient in verifying the parentage of 390 F1 lines. The KASP-based MAS was successfully applied to a maize pro-vitamin A (PVA) breeding program and for introgressing the aflatoxin resistance gene into elite tropical maize lines. Conclusion: This improved workflow has helped accelerate maize improvement activities of IITA's Maize Improvement Program and facilitated DNA fingerprinting for tracking improved crop varieties. National Agricultural Research Systems (NARS) in developing countries can adopt this workflow to fast-track molecular marker-based genotyping for crop improvement.

Vitamin A deficiency poses health risks for children, pregnant women, and nursing mothers in sub-Saharan Africa (SSA) and Southeast Asia. Provitamin A–biofortified maize varieties can contribute to minimizing the adverse effects of vitamin A deficiency in areas where maize is a staple food crop. Identifying suitable testers is important to breed provitamin A–biofortified hybrid maize. This study was therefore conducted to 1) assess the suitability of maize inbred lines with contrasting levels of provitamin A (one with high and one with low provitamin A concentration) to assess the combining ability of maize inbred lines in accumulating provitamin A and other carotenoids, and grain yield, 2) confirm the mode of inheritance of provitamin A and grain yield, and 3) identify promising inbred lines with desirable combining ability effects for use to develop high-yielding provitamin A–biofortified hybrids. The inbreds crossed to the two inbred testers were evaluated in four environments for the carotenoid content and eight environments for the agronomic performance. The combined analysis of variance revealed a significant genetic variation among the testcrosses for all carotenoids, grain yield, and other agronomic traits. The mode of inheritance for grain yield, other agronomic traits, provitamin A, and other carotenoids was regulated by both additive and non-additive gene effects with a prominence of additive gene effects. The high provitamin A tester that displayed positive GCA effects for β-carotene and provitamin A content, broader agronomic performance of testcrosses, and higher levels of provitamin A in testcrosses can be considered suitable for breeding programs developing provitamin A–biofortified hybrids. The inbred lines TZI2012, TZI2142, TZI2130, TZI2065-2, TZI2161, TZI2025, TZI1278, TZI1314, TZI1304, and TZI2032 with positive GCA effects for grain yield and provitamin A content could be used as parental lines to develop source population of new inbred lines and high-yielding hybrids with elevated levels of provitamin A. The best performing hybrids are promising for release as high-yielding provitamin A maize hybrids after further evaluations.

Biofortification of provitamin A in maize is an attractive and sustainable remedy to the problem of vitamin A deficiency in developing countries. The utilization of molecular markers represents a promising avenue to facilitate the development of provitamin A (PVA)-enriched maize varieties. We screened 752 diverse tropical yellow/orange maize lines using kompetitive allele-specific PCR (KASP) makers to validate the use of KASP markers in PVA maize breeding. To this end, a total of 161 yellow/orange inbred lines, selected from among the 752 lines, were evaluated for their endosperm PVA and other carotenoid compounds levels in two separate trials composed of 63 and 98 inbred lines in 2020 and 2021, respectively. Significant differences (p < 0.001) were observed among the yellow maize inbred lines studied for all carotenoid profiles. An inbred line TZMI1017, introduced by the International Institute of Tropical Agriculture (IITA) showed the highest level of PVA (12.99 µg/g) and β-carotene (12.08 µg/g). The molecular screening showed 43 yellow maize inbred lines carrying at least three of the favorable alleles of the KASP markers. TZMI1017 inbred line also carried the favorable alleles of almost all markers. In addition, nine locally developed inbred lines had medium to high PVA concentrations varying from 5.11 µg/g to 10.76 µg/g and harbored the favorable alleles of all the KASP PVA markers. Association analysis between molecular markers and PVA content variation in the yellow/orange maize inbred lines did not reveal a significant, predictable correlation. Further investigation is warranted to elucidate the underlying genetic architecture of the PVA content in this germplasm. However, we recommend strategic utilization of the maize-inbred lines with higher PVA content to enhance the PVA profile of the breeding program's germplasm. [ABSTRACT FROM AUTHOR]

Maize is an important food and industrial cereal crop that serves as the main source of energy for millions of low-income people in sub-Saharan Africa (SSA), but its production and productivity are constrained by many constraints, among which the fall armyworm (FAW) is the major one. The use of insecticides is the most effective control measure for the FAW. However, excessive use of chemical insecticides has environmental and health implications, and it can be expensive for resource-poor farmers. The objective of this study was to evaluate the extent of variation in yield losses due to the FAW among some elite maize open-pollinated varieties (OPVs) under two levels of insecticide application and control (0 application). In a two-year field study, 10 elite maize OPVs were evaluated under two levels of emamectin benzoate (5% WDG) applications and the control: 75 and 150 mL of spray solution per 20 L of water. The experimental design was a randomized complete block with three replications. The data were collected on grain yield (GY) and FAW leaf damage rating (LDR). The LDR was conducted on a 1–9 scale and used to categorize the maize varieties as resistant (1–4), moderately resistant (4–6), and susceptible (6–9). Significant varietal differences were obtained for GY and LDRs. The GY of the varieties under control (0 mL), 75 and 150 mL insecticide applications ranged from 3.3 t ha−1 (DTSTR-Y SYN-13) to 4.6 t ha−1 (PVA SYN-3), from 4.5 t ha−1 (DTSTR-Y SYN-13) to 6.4 t ha−1 (PVA SYN-13), and from 4.2 t ha−1 (DTSTR-Y SYN-13) to 6 t ha−1 (DTSTR-Y SYN-14), respectively. No significant differences in GY were found between the application of 75 and 150 mL of insecticide application. The relative loss in GY among the varieties under control (0 mL) differed with an increase in the level of insecticide application. The relative GY loss at the 75 mL insecticide application ranged from 18% (PVA SYN-3) to 38% (DTSTR-Y SYN-15) with a mean of 27%, whereas at the 150 mL insecticide application, it varied from 13% (PVA SYN-3) to 42% (DTSTR-Y SYN-15), with a mean of 26%. All the varieties exhibited moderate resistance to FAW, except DTSTR-Y SYN-14, which was susceptible. The varieties PVA SYN-3 and PVA SYN-13 were the most consistent in GY across the three insecticide treatment levels. The mean performance of the varieties for FAW leaf damage ranged from 4.0 (SAMMAZ-15) to 6.2 (DTSTR-Y SYN-14), from 4.5 (SAMMAZ-15) to 6.3 (PVA SYN-6), from 4.5 (SAMMAZ-15) to 6.3 (DTSTR-Y SYN-14), and from 3.5 (SAMMAZ-15) to 5 (DTSTR-Y SYN-14) for LDR 1, LDR 2, LDR 3, and LDR 4, respectively. The use of moderately resistant varieties, combined with timely spraying of emamectin benzoate at 75 mL provided adequate management for the FAW infestation and sustained high maize grain yield. [ABSTRACT FROM AUTHOR]

Sparse testing early in the SARS-CoV-2 pandemic hinders estimation of the dates and origins of initial case importations. Here, the authors show that the main source of cases imported from China shifted from Wuhan to other Chinese cities by mid-February, especially for African locations.

Abstract Biofortified maize varieties form an essential part of a nutritious diet; available evidence suggests that different processing methods may affect the final food products. The study aimed to evaluate the effects of processing (roasting) and harvesting time on the bioactive components (lutein, zeaxanthin, β-cryptoxanthin, phytate, tannin and vitamin C) and colour properties (L*, a*, b*), of biofortified orange maize. The orange maize hybrids used for the study were obtained from the International Institute of Tropical Agriculture (IITA) diverse lines with high provitamin A (PVA) content. The results showed that harvesting time and roasting methods significantly (P ≤ 0.001) affected the colour properties. The positive values of ∆b* 30.7, 36.0 and 38.1 at 20 days after pollination (DAP), 27DAP and 34DAP, respectively showed that the intensity of orange colour increased with delay in harvesting time. In unprocessed freshly harvested orange hybrid maize; lutein, zeaxanthin, β-cryptoxanthin, tannin and vitamin C increased with an increase in harvesting time. For roasted hybrid, the mean concentrations of all the bioactive components increased with increases in harvesting time except for tannin and vitamin C that showed a decrease at 20DAP and 27DAP. The results revealed that processing and time of harvest affect the levels of non-provitamin A carotenoids, tannins, phytic acid, Vitamin C and the colour properties of biofortified maize genotypes.

The study evaluated the fodder potential of 42 promising drought-tolerant (DT) three-way cross maize (Zea mays L.) hybrids, 11 commercial hybrid checks, and 1 local variety check under irrigation. Agronomic and laboratory trials were conducted to determine their morphological traits and fodder potential. Hierarchical cluster analysis (HCA) to group cultivars into clusters is based on quantity, quality, and the combination of both variables. Selection of potential food-feed cultivars was based on the quantity traits (grain and biomass yield) and quality traits crude protein (CP), in vitro organic matter digestibility (IVOMD), and metabolizable energy (ME). Variation was found for dry matter yield (DMY) at harvest as commercial hybrid recording the maximum DMY of 14.1 t ha−1 and the highest grain yield of 1.4 t ha−1 (P 0.01) in both commercial hybrids (7.2 MJ/kg DM) and DT hybrid (7.2 MJ/kg DM), while the highest ME (7.6 MJ/kg DM) was recorded for the local check. Ranking of the hybrids based on grain yield, DMY, CP, ME, and IVOMD showed that cluster subgroup A3 (M1124–24, M1527-7, 30F32, and M1427-6) and A4 (M1427-3, SC637, and M1627-11) exhibited the best potential traits and can therefore be recommended for commercial cultivation following adoption trials by farmers.

Breeding maize with high contents of zinc, iron and provitamin A (PVA) could be effective in mitigating micronutrient deficiency in developing countries with a high reliance on maize-based diets. Information on the mode of inheritance of zinc, iron, PVA and grain yield (GY) would facilitate the development of varieties with enhanced contents of these nutrients. Twenty-four yellow to orange maize inbred lines and their 96 F1 hybrids generated using North Carolina Design II, were evaluated alongside four checks for two years at two locations in Nigeria. The effects of environment, hybrid and inbred line were significant for GY and contents of zinc, iron and PVA. The GY, and contents of zinc, iron and PVA of the hybrids ranged from 1.49 to 6.05 t ha−1, 22.51 to 33.33 mg kg−1, 20.04 to 29.65 mg kg−1 and 3.55 to 15.28 µg g−1, respectively. Additive gene effects controlled the accumulation of PVA and Fe, whereas both additive and non-additive gene effects controlled the inheritance of Zn and GY. Inbred lines with high general combining ability for GY and single or multiple micronutrients were identified, and could be used to develop hybrids and synthetics that combine high GY with high micronutrient content. Six hybrids combined high GY with high contents of all three micronutrients, and are recommended for further evaluation and possible release. Our study revealed the feasibility of enriching maize with multiple micronutrients without compromising grain yield.

The study evaluates the effects of genotype, maturity, and growing location on the functional and pasting properties of freshly harvested orange maize hybrids and open-pollinated varieties (OPVs). Eight fresh orange maize hybrid and eight fresh maize OPV, including the control, were harvested at three stages: 20, 27, and 34 days after planting (DAP). The freshly harvested maize samples were lyophilized and characterized for the pasting and functional properties using standard laboratory methods. The peak viscosity, final viscosity, and swelling power of the OPVs increased between 20 and 27 DAP. Additionally, the water absorption capacity increased between 20 and 27 DAP for the maize hybrids, with a decreasing trend between 27 and 34 DAP. However, genotypes 2, from the orange maize hybrid, and 5, amongst the OPV, were outstanding with the highest peak viscosities, indicating good final product quality. The combined ANOVA for the fresh orange maize hybrid and OPV showed a highly significant effect (p ≤ 0.01 and p ≤ 0.001) for the maturity and location on the pasting and functional properties except for the pasting temperature, final viscosity, and pasting time which showed no significant effect. In contrast, the location by genotypes by maturity interactions had no significant effects on the pasting and functional properties of the fresh maize hybrid and the orange OPV except only for the setback, which was highly significant at p ≤ 0.001. Nutritionists, food scientists, and maize breeders could use the information from this study to select the best maize genotypes at the appropriate harvesting period suitable for the production of the preferred maize-based products of consumers.

Time lags in reporting to national surveillance systems represent a major barrier for the control of infectious diseases, preventing timely decision making and resource allocation. This issue is particularly acute for infectious diseases like malaria, which often impact rural and remote communities the hardest. In Guyana, a country located in South America, poor connectivity among remote malaria-endemic regions hampers surveillance efforts, making reporting delays a key challenge for elimination. Here, we analyze 13 years of malaria surveillance data, identifying key correlates of time lags between clinical cases occurring and being added to the central data system. We develop nowcasting methods that use historical patterns of reporting delays to estimate occurred-but-not-reported monthly malaria cases. To assess their performance, we implemented them retrospectively, using only information that would have been available at the time of estimation, and found that they substantially enhanced the estimates of malaria cases. Specifically, we found that the best performing models achieved up to two-fold improvements in accuracy (or error reduction) over known cases in selected regions. Our approach provides a simple, generalizable tool to improve malaria surveillance in endemic countries and is currently being implemented to help guide existing resource allocation and elimination efforts.