Institut du Sahel

Abstract Maize ( Zea mays L .) ranks as the second most widely cultivated crop in Nigeria, valued for its adaptability to diverse agro-climatic conditions and its multifaceted role in food security, animal feed, and industrial uses. This study explores farmers’ preferences for and adoption of drought-tolerant maize varieties (SAMMAZs), developed and issued by Ahmadu Bello University’s Institute for Agricultural Research (IAR), and cultivated widely across Northern Nigeria, a region responsible for over 75% of the country’s maize production. With reference to cross-sectional data gathered from 850 maize farmers (715 men and 135 women) during the 2019-2024 farming seasons and with aid of descriptive statistic and regression models, the study highlights notable differences in varietal preferences. Male farmers prioritized high grain yield (90.6%), drought tolerance (79%), and low fertilizer input (54.8%). Meanwhile, female farmers showed greater preference for uniform growth (85.3%), high grain yield (72.1%), and low fertilizer requirements (59.4%). Statistical t-test indicated a significant yield advantage for the SAMMAZ51 (4,987.02 kg/ha) compared to farmer varieties (1,718.27 kg/ha), at 1% level of probability. The multivariate Probit regression models using Maximum likelihood with complete information (FIML) and endogenous switching regression model (ESRM)established key socioeconomic and institutional variables that determined choice of SAMMAZs, and factors that influenced productivity and gross margin of these products. Tobit regression analysis identified primal factors that influenced intensity of adoption to encompass the availability of extension and research services, closeness to input centers, credit availability, and assistance from both public and private entities. These results highlight how crucial it is to match farmers’ practical demands with crop breeding initiatives, particularly when it comes to qualities like market value, drought resilience, and yield potential.

Coloboma is due to a defect in the closure of the colobomic cleft generally occurring between the 5th and 7th week of embryonic life. Coloboma can affect the adnexa and/or the eyeball. We report the iconography of two cases of ocular colobomas and one case of eyelids coloboma at the IOTA CHU. Case 1: This was a 32-year-old patient who consulted for decreased visual acuity in the left eye. The clinical examination found visual acuity of 10/10 in the right eye and hand movement in the left eye. Biomicroscopic examination revealed an iris and chorioretinal coloboma encompassing the papilla. Case 2: This was a 3-year-old child. Who consulted for eyelid malformation since birth. On ophthalmological examination, there was a bilateral coloboma of the inner half of the upper eyelid, associated with an underlying symblepharon and left eye corneal dystrophy. Our course of action consisted of a release of the symblepharon followed by a blepharoplasty which allowed a good anatomical and functional restitution. Case 3: This was a 15-year-old patient who consulted for bilateral visual acuity loss measured by counting fingers at 1m in the right eye and counting fingers at 3m in the left eye. The biomicroscopic examination found a bilateral papillary coloboma associated with a bilateral progressive cataract, an old detachment of the left retina. The etiological assessment was unremarkable. Conclusion: Coloboma is a congenital condition that can affect all parts of the eye. We reported three cases of colobomas, one palpebral, one iris and chorioretinal, and finally, one papillary associated with other ocular pathologies.

The promotion of climate-resilient practices (CRPs) requires the development of the capacity of farmers to adopt these practices owing to the knowledge-intensive nature of technologies. Extension services serve as a conduit for facilitating the conceptualization of CRPs and are instrumental in improving the resiliency and mitigation of climate change. We used a social-ecological framework and a multivariate probit model to analyze the drivers of the CRP uptake in moisture-stressed areas in Ethiopia, with a particular focus on extension services. Unlike previous studies that investigated a single technology, we considered a bundle of technologies. We focused on the use of two capital-intensive CRPs (drought-resistant seed and inorganic fertilizer) and four knowledge-intensive CRPs (minimum tillage, farmyard manure, water-saving technology, and crop residue retention). The role of extension services in promoting other CRPs beyond input and capital-intensive technologies was insignificant. Heterogeneity analysis revealed that the correlation between extension services and the adoption of other knowledge-intensive natural resource management practices holds irrespective of the proximity to the extension service providers. This finding highlights the need for targeted and tailored interventions that support farmers to address the challenges faced by them in moisture-stressed areas. Accordingly, we propose continuously improving the ability of the extension service providers to promote climate-change adaptation knowledge and practices. This should be accompanied by efforts to strengthen a pluralistic extension system, improve land tenure security, and decrease transaction costs for farmers through output market linkages.

Abstract The promotion of improved maize varieties and chemical fertilisers underscores many policy approaches addressing multiple production risks such as poor soil fertility and drought. However, the unsustainable use of chemical fertilisers has important implications for soil degradation. The synergies between improved maize varieties and sustainable land use management practices such as the use of organic fertilisers (e.g., manure) are poorly documented, despite the role of manure in enhancing soil organic matter. Employing nationally representative household survey data in Nigeria, this study utilises multivalued inverse probability weighted regression adjustment, entropy balancing and a multinomial endogenous switching regression model to determine the effects of the adoption of drought‐tolerant maize varieties (DTMVs) and organic fertiliser on farm households' productivity, per capita total expenditure and per capita food expenditure. Controlling for farm households' observables and unobservables, the estimation results of the average treatment effects show that the highest pay‐off on productivity and welfare outcomes is achieved when DTMVs and manure are jointly adopted. Also, wealth indicators, access to loans and access to extension services significantly influenced individual and combinatory packages of DTMVs and manure application adoption. This study underlines the significance of the joint adoption of DTMVs and manure application on rural farmers' productivity and welfare and a substantial contribution to achieving sustainable agricultural practices.

Introduction: Corneal perforations are a major cause of ocular morbidity and blindness. Several surgical techniques can be used to treat them, including conjunctival covering, which has numerous therapeutic properties and reduces the risk of anatomical loss. Observation: We present a series of five (5) cases admitted to the ophthalmology department for ocular pain, in whom the clinical examination concluded a corneal perforation. The etiologies were traumatic in three patients, Mooren's ulcer in one and undetermined in another. Conjunctival covering was the technique used to manage the patients. Visual acuity improved in two of our patients after surgery, and remained almost unchanged in one. Two patients were lost to follow-up. Conclusion: Despite the advancement and promotion of new techniques, conjunctival covering still has its place in the management of corneal perforations, especially when the technical platform is weak.

Summary: In Mali, the increase in the number of road accidents is proportional to the increase in the number of cars in circulation. A study of public transport drivers revealed that 23.1% of the drivers surveyed were unfit to drive out of a sample of 385 drivers. The objective of this study was to assess the visual aptitude for driving of inter-urban public transport drivers on the RN 6 and RN 30 in Fana. Results: The study involved 150 collective transport drivers, the majority of whom were in the 30-39 age group, representing 46.7% (n=70) with extremes of 20 and 68 years, the average age being 35.81±9.66 years. A total of 14.7% (n=22) of the drivers surveyed were unfit to drive and the causes of reduced visual acuity among unfit drivers were cataracts with 36.36% (n=8), followed by optic neuropathies with 22.73% (n=5) and ametropias with 18.19% (n=4). With regard to the relationship between the age of the drivers and visual aptitude for driving, the study revealed that 46.15% (n=6) of the drivers aged over 50 years were unfit. Conclusion: The results of this study show the need to make the ophthalmological examination compulsory when issuing and renewing a driving licence throughout Mali.

This study described the different eye injuries among patients with malignant hypertension associated with cardiovascular comorbidity.

This study reports on the adoption and impacts of CGIAR-related maize varieties in 18 major maize-producing countries in sub-Saharan Africa (SSA) during 1995–2015. Of the 1345 maize varieties released during this timeframe, approximately 60% had a known CGIAR parentage. About 34% (9.5 million ha) of the total maize area in 2015 was cultivated with 'new' CGIAR-related maize varieties released between 1995 and 2015. In the same year, an additional 13% of the maize area was cultivated with 'old' CGIAR-related maize varieties released before 1995. The aggregate annual economic benefit of using new CGIAR-related maize germplasm for yield increase in SSA was estimated at US$1.1–1.6 billion in 2015, which we attributed equally to co-investments by CGIAR funders, public-sector national research and extension programs, and private sector partners. Given that the annual global investment in CGIAR maize breeding at its maximum was US$30 million, the benefit-cost ratios for the CGIAR investment and CGIAR-attributable portion of economic benefits varied from 12:1–17:1, under the assumption of a 5-year lag in the research investment to yield returns. The study also discusses the methodological challenges involved in large-scale impact assessments. Post-2015 CGIAR tropical maize breeding efforts have had a strong emphasis on stress tolerance.

The main objective of this study was to evaluate the effect of CYP2B6 and CYP3A4 polymorphisms on the virological and immunologic responses of HIV patients. A total of 153 HIV-positive patients were enlisted for the study. Viral load and median CD4 T cell counts were evaluated at baseline and month 6 (M6). Samples were identified using TaqMan genotyping assays. The AG in CYP2B6 rs2279343 was associated with VLS compared to homozygous AA. In the dominant model, the AG/GG genotypes were associated with VLS compared to the AA genotype. Moreover, in overdominant model, the AG genotype was associated with VLS compared to AA/GG. Regarding immunological response, only the AG in SNP rs2279343 CYP2B6 was associated with an increase in CD4 cell count between baseline and M6. In CYP2B6 rs3745274, the CD4 cell count at M6 was higher than that of baseline for GG carriers and for GT carriers. In CYP3A4 rs2740574, the TC carriers showed a higher median CD4 count at M6 compared to that of the baseline count, as well as for CC carriers. The best genotypes combination associated with CD4 cell count improvement were AA/AG in SNP rs2279343 and GG/GT in SNP rs3745274. Our findings support the fact that CYP2B6 rs2279343 could help in the prediction of VLS and both SNPs rs3745274 and rs2279343 in CYP2B6 and CYP3A4 rs2740574 were associated with immune recovery in Malian HIV-positive patients.

Farmers in developing countries routinely misperceive or misreport input quality for various reasons, which introduces substantial measurement error in farm survey data. In this paper, we motivate and illustrate, both analytically and empirically, the inferential and behavioral implications of misperception and misreporting using a unique crop variety identification data from Nigeria. Using a non-parametric framework for testing the presence of measurement error, we show that crop variety misclassification in our data is mostly driven by misperception. We then demonstrate the inferential challenges of treating misperception as misreporting and vice versa. Finally, we show that misperception induces crowding-in(out) of complementary agricultural inputs but these misperception-driven input allocations may not necessarily be yield-enhancing. As such, rectifying misperception by addressing agricultural input market imperfections may improve farmers’ investment choices and productivity outcomes.