Search Results (718)

Neurological manifestations associated with human parvovirus B19 (B19V) infections are rare and varied. Acute encephalitis and encephalopathy are the most common, accounting for 38.8% of all neurological manifestations associated with human B19V. Herein, we report on the clinical features of 13 laboratory-confirmed human cases of B19V-associated encephalitis in Senegal in the framework of a hospital-based surveillance of acute viral encephalitis conducted from 2021 to 2023. Overall, B19V was detected from 13 cerebrospinal fluid samples using specific real time PCR. The mean age was 16.7 years among B19V-positive patients, with a higher prevalence in 0–5-year-old children and the sex ratio (male/female) was 2.25. The B19V-positive patients mainly exhibited hypoleukocytosis, normal glycorrhachia, and normal proteinorrachia in the cerebrospinal fluid. While the main neurological symptoms included meningeal and infectious syndromes. Furthermore, three complete B19V genome sequences were successfully characterized using next-generation sequencing. The newly characterized sequences belonged to the genotype 1a and represent, to date, the first complete B19V genome sequences from Senegal. These sequences could be useful not only in future phylodynamic studies of B19V but also in the development of prevention or treatment countermeasures. Our study is noteworthy for the identification of acute B19V-associated encephalitis in Senegal More investigations on the risk factors associated with B19V transmission in Africa are warranted. Full article

The adaptation of Faidherbia albida (Del.) A. Chev. to drought conditions, its reverse phenology, ability to improve soil fertility, importance as source of forage, and its medicinal properties make it an excellent tree for Sub-Saharan African communities. However, there has been little effort to develop improved genotypes of F. albida, in part because there is relatively little information about phenotypic and genetic variation within this species. This study’s aim was to characterize the genetic diversity of F. albida among Sub-Saharan natural populations with the goal of identifying material for the improvement of the species in Cameroon and other African countries. We genotyped seven simple sequence repeat (SSR) loci in 267 individuals, 15 populations, and 8 countries in Sub-Saharan Africa representing the range of distribution of F. albida. A total of 32 alleles were identified. The highest level of polymorphism was found in Senegal and Ethiopia. Structure analysis of allelic distributions differentiated the 15 populations into three clusters representing West, East, and South Africa. However, one population in Ethiopia (Rama) was strikingly similar to the West Africa cluster. Genetic diversity decreased from West and East Africa to South Africa. These results support the hypothesis that F. albida originated in West or East Africa and subsequently spread to South Africa. Further sequence-based genotyping of these and additional populations will provide an accurate picture of the origin and subsequent spread of this species and reveal new sources of genetic variation for its improvement. Full article

The adoption of a new technology is well described by an S-curve. It starts with a slow initial introduction, faster growth, and a final low-pace stage that corresponds to saturation. Once the innovation is introduced and progressively adopted, prior to saturation, some of the initial owners will begin selling their initially owned goods for different reasons, including lack of satisfaction, upgrading to a newer model, or other special unrevealed reasons. In a given market, new and second-hand products will coexist that will find new owners. The evolution of the two qualities of the same product will progress to a given equilibrium and a final ratio specific to each market. With the hypothesis of second-hand goods viewed as a new technology for lower budgets in the market, their adoption can also be described by the S-curve. The questions to be answered will relate to the dynamics of adoption of the two technologies, the ratio at equilibrium between new and used products in a market, and the delay required before equilibrium is achieved. In this manuscript, a realistic model is presented to approach and analyze the adoption of electric vehicles (EVs) with the mix of new and used vehicles with new registrations. The EV transition is presented with an adoption represented by the S-curve; the ratio of new to used EVs with new registrations is also presented in a context of high demand of used EVs and a context of rapid depreciation of EVs corresponding to lower demand of pre-owned EVs. The model predicts the number of years required before an equilibrium is reached in the ratio between used and new EVs in new registrations for a given market. Full article

Despite extensive experience with influenza surveillance in humans in Senegal, there is limited knowledge about the actual situation and genetic diversity of avian influenza viruses (AIVs) circulating in the country, hindering control measures and pandemic risk assessment. Therefore, as part of the “One Health” approach to influenza surveillance, we conducted active AIV surveillance in two live bird markets (LBMs) in Dakar to better understand the dynamics and diversity of influenza viruses in Senegal, obtain genetic profiles of circulating AIVs, and assess the risk of emergence of novel strains and their transmission to humans. Cloacal swabs from poultry and environmental samples collected weekly from the two LBMs were screened by RT-qPCR for H5, H7, and H9 AIVs. Subsequently, a subset of H9-positive samples was selected for whole sequencing. From December 2023 to October 2024, 499 samples were tested, and AIV was detected in 58.3% of them. Among these, A/H9N2 was the only subtype detected in both markets, with a detection rate of 47.7% (82/172) in Thiaroye and 35.3% (42/119) in Tilene, resulting in an overall positivity rate of 42.6% (124/291). Genome sequencing of 22 A/H9N2 isolates, including 11 poultry drinking water samples, 7 carcass wash water samples, 3 fecal samples, and 1 cloacal swab, yielded 7 complete and 15 partial genomic sequences. Phylogenetic analyses of the resulting sequences showed that the A/H9N2 isolates obtained in this study formed a monophyletic cluster and were closely related to the Senegalese human strain (A/Senegal/0243/2019) identified through the national influenza sentinel surveillance program. These strains were also closely related to the A/H9N2 viruses of the G1 lineage circulating in neighboring countries, suggesting cross-border transmission. The A/H9N2 strains carried the low pathogenicity RSSR/GLF motif at the HA cleavage site and possessed several key amino acid mutations, including HA-I155T and HA-Q226L, which are associated with human host adaptation, PB2-T105V, PB2-A661T, and PB2-A588V, which are linked to the human-to-human transmission and increased polymerase activity, NS2-T14M, NS2-M100I, NS1-I106M, NS1-V222M, NS1-E223A, NS1-I226V, NS1-E227G, and NS1-P228S, which are known to alter virulence (increased or reduced) in humans or mice, and M2-S31N, which promotes drug resistance. Seven potential N-glycosylation sites were predicted in the HA protein and six in the NA protein. The selection pressure analysis revealed that the A/H9N2 isolates were primarily under neutral evolution or purifying selection pressure. Overall, our findings highlight the potential for cross-species transmission of Senegalese A/H9N2 viruses, emphasizing the need for sustained monitoring of these viruses in both animal and human populations. Full article

Logistic regression models encounter challenges with correlated predictors and influential outliers. This study integrates robust estimators, including the Bianco–Yohai estimator (BY) and conditionally unbiased bounded influence estimator (CE), with the logistic Liu (LL), logistic ridge (LR), and logistic KL (KL) estimators. The resulting estimators (LL-BY, LL-CE, LR-BY, LR-CE, KL-BY, and KL-CE) are evaluated through simulations and real-life examples. KL-BY emerges as the preferred choice, displaying superior performance by reducing mean squared error (MSE) values and exhibiting robustness against multicollinearity and outliers. Adopting KL-BY can lead to stable and accurate predictions in logistic regression analysis. Full article

Glioblastoma (GBM) is a devastating malignant brain tumor with a poor prognosis. GBM is associated with radioresistance. Post-translational modifications (PTMs) such as protein phosphorylation can play an important role in the cellular response to radiation. To better understand the early cellular activities after radiation in GBM, we carried out a phospho-proteomic study on the U251 cell line 3 h after X-ray irradiation (6Gy) and on non-irradiated cells. Our study showed a strong modification of proteoform phosphorylation in response to radiation. We found 453 differentially expressed phosphopeptides (DEPs), with 211 being upregulated and 242 being downregulated. A GO enrichment analysis of DEPs showed a strong enrichment of the signaling pathways involved in DNA damage response after irradiation and categorized them into biological processes (BPs), cellular components (CCs) and molecular functions (MFs). Certain accessions such as BRCA1, MDC1, H2AX, MDC1, TP53BP1 were dynamically altered in our fraction and are highly associated with the signaling pathways enriched after radiation. Full article

The aim of this study is to characterize the compound extremes of rainfall and temperature in Côte d’Ivoire. For this purpose, we analyzed the outputs of fourteen (14) climate models from the CORDEX-Africa project. Results show an increase (approximately 4.3 °C) in the surface temperature and a decrease (5.90%) of the mean rainfall in the near (2036–2065) and far futures (2071–2100) over Côte d’Ivoire during the January–February–March (JFM) period. The analysis of the compound extremes of the wet/warm type highlights an increase in the frequency of this climatic hazard in the northern and central parts of the country during the January–March (JFM) season in the near and far futures. The dry/warm mode will increase in the central and southern parts of the country in the near future and in the whole country in the far future. These increases in compound extremes could lead to an increase in droughts and natural disasters across the country and could have a negative impact on socio-economic activities, such as transportation and agricultural production. This work could provide decision support for political decision-makers in formulating future public policies for managing agricultural production, food security, and natural disasters. Full article

Conventional agriculture may not meet the needs of the growing human population and sustainable development. These issues necessitate a shift towards traditional foods and underutilized desert plants, offering promising sustainable agricultural and food security alternatives. ‘Panchkuta’, a blend of five plants (Prosopis cineraria, Acacia senegal, Capparis decidua, Cordia dichotoma, and Mangifera indica), is a traditional food combination from (semi) arid regions. In this study, the bioactive metabolites were identified through analytical techniques, including TLC and GC-MS analysis. Tapping these underexplored plants can help design and develop healthy functional foods and nutraceutical products. Full article

Senegalese cities have experienced rapid urbanisation, leading to profound landscape changes. Dakar, one of Senegalese’s fastest-growing cities, is experiencing rapid urban expansion, significantly reducing green spaces. These green spaces, essential for urban sustainability and resilience, have become increasingly scarce, affecting the city’s environment and the quality of life for its residents. This study aims to assess the spatiotemporal changes in Dakar’s green spaces from 1990 to 2022. Using satellite imagery, this study produces land use maps to quantify green space coverage over the years. The results show a gradual decline in green spaces in Dakar between 1990 and 2022. In 1990, green spaces covered an estimated 13.36% of Dakar’s area, which decreased significantly to 9.54% by 2022. In contrast, other land uses, such as built-up areas, increased significantly over this period, rising from 19.23% in 1990 to 39.34% in 2022. Moreover, built-up areas are not the sole contributor to the reduction of green spaces in Dakar. The study revealed that, between 1990 and 2022, 5.49% of green spaces were converted into bare soil due to excessive tree cutting. This pattern highlights the growing challenge of green space availability as built-up areas expand rapidly, particularly when growth is unplanned. This study underscores the importance of sustainable urban planning that integrates the protection and conservation of Dakar’s vegetation to preserve vital ecosystem services. Full article

Background: Persistent inequities in access to vaccinations pose challenges for immunization programs worldwide. Innovations facilitating vaccine delivery, such as leveraging vaccine thermostability through a Controlled Temperature Chain (CTC), have emerged as a potential solution to increase coverage in low- and middle-income countries (LMICs) countries such as Côte d’Ivoire, reducing dependence on the cold chain and improving vaccine delivery efficiency. However, the added value of thermostable vaccines and their integration into national immunization programs is under-recognized by stakeholders. This consultation aimed to convene key immunization stakeholders in Côte d’Ivoire in order to examine their perceptions regarding the value of vaccine thermostability to address barriers to outreach and equity in immunization programs. Methods: A novel workshop model involving structured group discussions was used to document the viewpoints of national stakeholders representing different areas of the immunization program. They prioritized barriers undermining coverage and equity in their country and explored the potential impact of CTC on the immunization program in the context of thermostable vaccines. The vaccines discussed were for Hepatitis B, Human Papillomavirus, and Meningitis. Results: The workshop outcomes highlighted the context and vaccine-specific variation of the importance of certain barriers, emphasizing the need for tailored strategies. The barriers considered most likely to be alleviated by vaccine thermostability were under the categories of human resource management, vaccine supply and logistics, and services delivery. The least relevant category of barriers concerned demand generation. Conclusions: The consultation provided valuable insights into stakeholder perspectives, priorities, and conditions for the effective integration of thermostable vaccines, informing future product development and policy decisions to optimize vaccine delivery and address immunization challenges in LMICs. Full article

This study examines the framing of African technological innovations in Western media over the past two decades (2003–2023), focusing on four case studies: M-Pesa, LifeBank, FarmDrive, and NigeriaSat-1. Using a qualitative research design that integrates content analysis and framing theory, we analyze how major media outlets, including the BBC, CNN, The Guardian, Reuters, and The New York Times, represent African innovations. The analysis reveals that media coverage tends to frame these innovations primarily through a humanitarian lens, emphasizing their role in addressing poverty, healthcare, and food security challenges. While highlighting the social impact of these technologies, this narrative often overlooks their broader potential for global scalability and industry disruption. To complement the content analysis, we conducted 24 semi-structured interviews with tech entrepreneurs, media professionals, and scholars from Kenya, Ghana, Nigeria, and Senegal, investigating their perspectives on how Western media coverage impacts investment and collaboration in African technological sectors. The interview findings confirm that such media portrayals hinder international investment and partnership opportunities by reinforcing the narrative that African technologies are primarily crisis management tools, rather than innovative solutions with global market potential. This article argues for a shift in this narrative, recommending policies that include strategic media advocacy, enhanced public relations, and increased investment in Research and Development. Full article

Recently, there has been an explosive growth in wireless devices capable of connecting to the Internet and utilizing various services anytime, anywhere, often while on the move. In the realm of the Internet, such devices are called mobile nodes. When these devices are in motion or traverse different domains while communicating, effective mobility management becomes essential to ensure the continuity of their services. Software-defined networking (SDN), a new paradigm in networking, offers numerous possibilities for addressing the challenges of mobility management. By decoupling the control and data planes, SDN enables greater flexibility and adaptability, making them a powerful framework for solving mobility-related issues. However, communication can still be momentarily disrupted due to frequent changes in IP addresses, a drop in radio signals, or configuration issues associated with gateways. Therefore, this paper introduces Routage Inter-domains in SDN (RI-SDN), a novel anchor-based routing method designed for inter-domain mobility in SDN architectures. The method identifies a suitable anchor domain, a critical intermediary domain that contributes to reducing delays during data transfer because it is the closest domain (i.e., node) to the destination. Once the anchor domain is identified, the best routing path is determined as the route with the smallest metric, incorporating elements such as bandwidth, flow operations, and the number of domain hops. Simulation results demonstrate significant improvements in data transfer delay and handover latency compared to existing methods. By leveraging SDN’s potential, RI-SDN presents a robust and innovative solution for real-world scenarios requiring reliable mobility management. Full article

This study examines projected changes in dry and wet spell probabilities in West Africa during the July–August–September monsoon season using a Markov chain approach. Four simulations of regional climate models from the CORDEX-Africa program were used to analyze projected changes in intraseasonal variability. The results show an increase in the probability of having a dry day, a dry day preceding a wet day, and a dry day preceding a dry day, and a decrease in the probability of wet days in the Sahel region under anthropogenic forcing scenarios RCP4.5 and RCP8.5. The decrease in wet days is stronger in the far future and under the RCP8.5 scenario (up to −30%). The study also finds that the probability of consecutive dry days (lasting at least 7 days and 10 days) is expected to increase in western Sahel, central Sahel, and the Sudanian Area under both scenarios, with stronger increases in the RCP8.5 scenario. In contrast, a decrease is expected over the Guinea Coast, with the changes being more important under the RCP4.5. Dry spell probabilities increasing in the Sahel areas and in the northern Sudanian Area is linked to the increase in the very wet days (R95P) in the daily rainfall intensity index (SDII). These changes in dry and wet spell probabilities are important for water management decisions and risk reduction in the energy and agricultural sectors. This study also highlights the need for decision-makers to implement mitigation and adaptation policies to minimize the adverse effects of climate change. Full article

The transition to renewable and sustainable energy sources is critical to solving the environmental and socioeconomic problems associated with the use of fossil fuels. This study uses an interdisciplinary approach to analyze the challenges and prospects of a sustainable energy transition in contexts with the recent discovery and exploitation of fossil resources. We study the case of Senegal from 2000 to 2027 and the role of recent discoveries of natural gas in its energy transition. In 2000, Senegal’s energy mix consisted of about 97% fossil energy and only 3% renewable energy. Since then, the country has developed renewable energy sources, including solar, hydro, and wind power, which currently account for about 30% of the total energy mix. At the same time, Senegal’s population and electricity production have grown significantly, leading to a fivefold increase in per capita energy consumption over the past two decades. Projections based on a long short-term memory model that predicts future electricity demand and energy balance suggest a structural shift in the energy mix, with natural gas, oil, and renewables at 47%, 32%, and 21%, respectively, by 2027. Overall, this study presents a comprehensive analysis that highlights the benefits of strategically using natural gas as a transition energy source in contexts with increased electricity demand and continued development of renewable energy sources. Full article