Comparative study of chicken egg yolk and quail egg yolk in two chilled canine semen extenders

The aim of this work was to substitute chicken egg yolk with quail egg yolk in two semen extenders and to evaluate the quality of the extended canine semen following chilled storage. Semen was pooled from male dogs (n= 4) of about 18-months old and body weight of about 28 kg. Four extenders were tested: (1) tris buffered chicken egg yolk extender (2) tris buffered quail egg yolk extender, (3) skimmed milk chicken egg yolk extender and (4) skimmed milk quail egg yolk extender. Semen was diluted with corresponding extender in the ratio 1:4. The diluted semen samples were analyzed for motility, mass activity, viability, abnormalities percentage and pH for three consecutive days. There was no significant difference (P>0.05) between chicken egg yolk and quail egg yolk in either tris diluent or skimmed milk extender with respect to pH, mass activity and sperm motility. Samples stored in both the tris and skimmed milk-based extenders with quail egg yolk displayed greater viability than those in chicken egg yolk but the difference was not significant (P>0.05). Viability, mass activity and sperm motility decreased as treatment days increased in both chicken and quail egg yolk extenders. Results showed that a pH of 6.5 was maintained from day 0 to day 3. There was no difference in semen quality between chicken and quail egg yolk in either the tris diluent or skimmed milk extender (P> 0.05). It was recommended that quail egg yolk could be substituted for chicken egg yolk in the two canine semen extenders. Further modifications of the diluents with quail egg yolk might produce an improved result. Keywords: Canine, Chicken Chilled, Egg yolk, Extenders, Quail, Seme

Persistence of Ebola virus RNA in some body fluids of Ebola virus disease (EVD) survivors – the Nigerian experience

Introduction: Ebola virus (EBOV) has been shown to persist in some body fluids of Ebola Virus Disease (EVD) survivors with implication for future transmission particularly in Nigeria where EVD was experienced for the first time in 2014. Thus, this paper was aimed at providing information on the duration of persistence of EBOV in Nigeria. Materials and Methods: Ten consenting EVD survivors were enrolled. Baseline specimens; urine and semen (males), urine and high vaginal swab (HVS) (females) were obtained within one month after discharge from the Ebola Treatment Centre (ETC) and subsequently every fortnight. Samples were analyzed using quantitative Real-Star Filovirus Screen RT-PCR kit 1.0 at the National Reference Laboratory in Lagos.Results: Ten EVD survivors comprising 4 (40%) males and 6 (60%) females with age ranges of 28 to >33 years (mean age: 33.0 ± 6.9 years) were evaluated. EBOV RNA was not detected in the urine of all the participants and HVS from the females. However, EBOV RNA was detected in the semen of all 4 (100%) male participants at baseline, and at 2 months after discharge from the ETC. Two men were still positive for EBOV RNA 4 months after discharge from the ETC despite persistent negative vireamia. Conclusions: Our data confirm that a negative viremia in the convalescent period is not predictive of the absence of the virus in semen. Despite an early clearance of the virus from the urine and HVS, there was persistence of EBOV RNA in semen of male survivors 4 months after recovery

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The distribution and pathogenicity of the seed mycoflora of two tomato varieties cultivated in western Nigeria

The seed mycoflora of two tomato varieties: Ibadan local and Ife 1 was investigated and a total of 18 fungal species in nine genera were isolated. Most of these fungi were present as surface contaminants, while the internally seed-borne fungi were Alternaria longissima, Aspergillus flavus, Aspergillus niger, Curvularia lunata, Fusarium moniliforme, Fusarium oxysporum and Phoma destructiva. When the internally seedborne fungi were tested for pathogenicity on blotter, all except A. flavus and A. niger exhibited varying degrees of pathogenicity to the two tomato varieties. The most pathogenic isolate on Ibadan local was F. oxysporum whereas P. destructiva was the most pathogenic on Ife 1. The fungal isolates were more pathogenic on inoculated seeds planted in sterilised soils than those in unsterilised soils.La mycologie des semences de deux varietes de tomate (Ibadan local et Ife 1) emit analysee et un total de neuf varietes etaient isolees. La plupart des champignons etaient localisees sur la surface, tandis que les champignons internes sont Alternaria longissima, Aspergillus niger, Curvularia lunata, Fusarium moniliforme, Fusarium oxysporum et Phoma destructiva. Les champignons rencontres dans les grains sont testes pour leur pathogenicite sur buvard et tous, sauf A. flavus et A. niger ont fait apparaitre de niveaux varies de pathogenicite aux deux varietes de tomate. Le pins pathogenique isole a Ibadan local etait F. oxysporum tandis que P. destructiva etait le plus pathogenique sur Ife 1. Les champignons isoles etaient plus virulents pour des grains inocules plantes dans des terres sterilisees que dans des terres non-sterilisees

Biostratigraphy and palaeoenvironment of deposition of Nsukka Formation, Anambra Basin, southeastern Nigeria

Biostratigraphy investigation of Nsukka Formation was carried out by subjecting well cutting samples obtained from Nzam-1 well to palynological studies with the view towards determining the relative geologic age and palaeoenvironment of deposition of the sediments. Samples were treated in the laboratory through digestion with hydrofluoric acid, sieving with 5 μm, oxidation with Nitric acid and mounting of the slides into sections with DPX mountant. A fairly high abundance and diversity of miospores were recovered, while the interval (847–1372 m) contains distinctive and diagnostic palynomorphs which are stratigraphically important. A Spinizonocolpites baculatus assemblage zone was established based on the basal occurrence of S. baculatus, Spinizonocolpites echinatus, Constructipollenites ineffectus, Periretisyncolpites sp. Periretisyncolpites giganteus, Monocolpites sp 1, Foveotriletes margaritae, Syncolporites marginatus, and Longapertites marginatus. The upper part of the interval is marked by association of Anacolosidites luidonisis (at top), Mauritiidites crassibaculatus, Retistephanocolpites williamsi, Proteacidites dehaani, Echitriporites trianguliformis, Proxapertites cursus, Retidiporites magdalenensis, S. baculatus, Retitricolpites gigeonetti, F. margaritae and Araucariacites sp. The Nsukka Formation is dated as Late Maastrichtian based on the co-occurrence of recovered index fossils. Importantly, Cretaceous–Tertiary (K/T) boundary is marked by high fossil content in the Maastrichtian sediments compared to paucity in palynomorph that characterise the overlying Paleocene facies. Palaeoenvironment of the analyzed section varies alternately from marginal marine to continental setting based on the presence of land-derived miospores and dinoflagellates

3D-printed biomimetic bone implant polymeric composite scaffolds

open access articleThis research introduced a new poly-ether-ether-ketone calcium hydroxyapatite (PEEK-cHAp) composite for a convenient, fast and inexpensive femur bone-implant scaffold with different lattice structures to mimic natural bone structure. Fused Deposition Modelling (FDM) was used to print a hybrid PEEK-based filament-bearing bioactive material suited for developing cHAp. Using FDM, the same bone scaffold PEEK will be fabricated, depending on the shape of the bone fracture. The scaffolds were examined for in-vitro bioactivity by immersing them in a simulated bodily fluid (SBF) solution. Furthermore, in-vitro cytotoxicity tests validated the suitability of the composite materials employed to create minimal toxicity of the scaffolds. After spreading PEEK nanoparticles in the grains, the suggested spherical nanoparticles cell expanded over time. The motif affected the microstructure of PEEK-cHAp in terms of grain size and 3D shape. The results established the proposed optimum design and suitable material for prospective bone implants, as required for biomimetic artificial bone regeneration and healing