Search Results (5)

Biomphalaria pfeifferi snails serve as the major intermediate host for intestinal schistosomiasis in Sudan. The genetic structure and infection status of 163 B. pfeifferi collected from six localities in Gezira State, Sudan (East Gezira, Greater Wadmedani, Hasahisa, North Umelgura, South Gezira, and Managil) were characterized. Cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S rRNA) mitochondrial genes were used for B. pfeifferi molecular identification and genetic diversity investigation. Schistosoma mansoni infection was detected using the traditional cercarial shedding and molecular methods (Sm^F/R primers). Five COI haplotypes and ten 16S haplotypes were identified, with haplotype diversity of 0.50 for COI and 0.11 for 16S. High evolutionary divergence was observed between groups (Fst = 0.94) for the COI, and low genetic divergence (Fst = 0.04) for the 16S, indicating genetic divergence among Sudanese B. pfeifferi, with the 16S showing lower divergence than the COI, consistent with a post-bottleneck population expansion. Cercarial shedding detected an overall infection prevalence of 3.6% (8/219), with only two snails from Hasahisa shedding S. mansoni cercariae. The Sm^F/R primers revealed a higher infection prevalence of 7.4% (12/163), with all S. mansoni positive samples found at the Hasahisa site. Findings highlight the value of molecular diagnostic tools for accurate surveillance and emphasize the need for site-specific control strategies. Full article

Biomphalaria pfeifferi is a key intermediate host for Schistosoma mansoni transmission in Sudan. In total, 27 complete mitochondrial genomes from seven B. pfeifferi populations in Gezira State, Sudan, were sequenced for the first time to investigate their population structure and phylogenetic relationships. This involved comparing the nucleotide composition, codon usage, rRNAs, and tRNAs of the East Gezira (EG), South Gezira (SG), Hasahisa (HA), Greater Wad Medani (GW), Managil (MA), and North Umelgura (NU1, NU3) populations. All 27 mitogenomes (13,688–13,696 bp) contained 37 genes with conserved AT/GC content (76.7/23.4%). Phylogenetic analysis revealed that although samples clustered within the same clade, B. pfeifferi from EG, SG, NU1, and NU3 grouped closely with B. pfeifferi from Kenya, whereas HA and GW samples formed distinct ancestral lineages. The MA population exhibited unique genetic characteristics, supported by phylogenetic trees and nucleotide/amino acid identity, suggesting the potential presence of a distinct B. pfeifferi subspecies that warrants further investigation. All protein-coding genes evolved under negative selection, with the amino acids of nad1 and nad6 being highly conserved, while nad3 exhibited some variation. Further research on the mitogenomic diversity of B. pfeifferi and other Biomphalaria species in Sudan and across Africa is needed in order to better understand the population structure and evolutionary history of Biomphalaria. Full article

Successful strategies that can contribute to poverty reduction and improve the livelihoods of the poor, particularly in Sub-Saharan Africa (SSA), are critically needed to address the technology adoption constraints. The objectives of this study were to assess the adoption level of improved technologies and management practices and to identify the key factors influencing their adoption in the major wheat-producing areas in the irrigated, arid, and heat-prone environments of Sudan. A farm survey was conducted in 2021 using a structured questionnaire that included almost all recommended technological options for optimum and sustainable wheat production. A total of 300 farmers, 93, 101, and 106 from Northern (NS), Kassala (KS), and Gezira (GS) states, respectively, were selected and interviewed. Besides descriptive statistics, a binary logistic model was used to identify the socioeconomic and production factors affecting farmers’ perceptions of improved and recommended technological options. The study found a wide range of adoption rates depending on the specific technology practice and the area surveyed. The lowest adoption rate was observed for land preparation (6.5%) in NS. Adoption rates ranging from 26–100% were observed for technologies such as the sowing date, the seed rate, seed treatment, the awareness of released varieties, nitrogen and phosphorus fertilizer application, and chemical weed control. The difference in the productivity of technological option adopters was significant (p = 0.015) compared to non-adopters. The binary logistic regression results showed that five out of seven explanatory variables hypothesized to influence wheat farmers’ perceptions on the decision to adopt improved and recommended technologies significantly influenced farmers’ decision to adopt the technologies. In particular, access to quality seeds, financial credit, and extension services were found to be the most critical determinants of adopting improved technologies. Approaches that bring together all stakeholders along the crop value chain, including policymakers, to jointly analyze, identify, and prioritize challenges and develop and apply solutions and work plans using feedback and learning mechanisms are expected to increase farmer awareness and adoption of improved technologies, ultimately leading to sustainable wheat production. Full article

Manure is a substantial source of ammonia volatilization into the atmosphere before and after soil application. The purpose of the study was to investigate the effects of temperature and alkalization treatments on the release of ammonia and ammonia recovery (AR) from cow manure and to characterize the chemical properties of the resultant effluents. In a closed glass reactor, 100 g of fresh cow manure was mixed with 100 mL of deionized water and the mixture was treated with various volume of KOH to increase the manure pH to 7, 9, and 12. Ammonia was distilled from the mixture at temperatures of 75, 85, 95, and 100 °C for a maximum of 5 h. Ammonia was received as diluted boric and sulfuric acids. Results indicated that the highest ammonia recovery was 86.3% and 90.2%, which were achieved at a pH of 12 and temperatures of 100 and 95 °C, respectively. The recovered ammonia in boric acid was higher than in sulfuric acid, except at a pH of 12 and temperatures of 95 and 100 °C. The effluents, after ammonia was removed, showed that the variation in pH ranged between 6.30 and 9.38. The electrical conductivity ranged between 4.5 and 9. (dS m⁻¹) and total potassium ranged between 9.4 and 57.2 mg kg⁻¹. Full article

There are several chemical indices that have been introduced in theoretical chemistry to measure the properties of molecular topology, such as distance-based topological indices, degree-based topological indices and counting-related topological indices. Among the degree-based topological indices, the atom-bond connectivity ( $ABC$ ) index and geometric–arithmetic ( $GA$ ) index are the most important, because of their chemical significance. Certain physicochemical properties, such as the boiling point, stability and strain energy, of chemical compounds are correlated by these topological indices. In this paper, we study the molecular topological properties of some special graphs. The indices $(ABC)$ , $(AB{C}_4)$ , $(GA)$ and $(G{A}_5)$ of these special graphs are computed. Full article