Cross-Diffusion Effect on Mixed Convective Fluid Flow through Horizontal Annulus

The unsteady mixed convective fluid flow through an annulus filled with a fluid-saturated porous medium is numerically investigated in this study in the presence of Cross-Diffusion effect and constant Heat Source. The flow configuration and coordinate system for an annulus which is horizontal position have been considered Details of the effect of several parameters controlling the velocity, temperature and concentration profiles are shown graphically and the observations are discussed. These parameters include the Non-Darcy parameter, Pressure gradient, Soret effect, Schmidt Number, Dufour effect, Eckert number and Prandtl Number. The effect of these dimensionless parameters mentioned above is observed either to enhance, to decrease or have no effect on the velocity, temperature and the concentration profiles. Keywords: Unsteady Flow, Cross-Diffusion effect, Constant heat source Effect

Fodder Crop Adoption through Push-Pull Technology (PPT) for Fall Armyworm (FAW) Control in Cereals Cropping Systems

There is an urgent need to increase grain yields and animal products due to increasing human population in Africa. Push-pull technology (PPT) is a conservation agriculture intercrop technology which protects and enhances natural resources productivity and ecosystem services in mixed farming systems. The technology involves growing of a cereal crop with a repellent intercrop, Desmodium genus (silverleaf, D. uncinatum and greenleaf, D. intortum) with grass such as Pennisetum purpureum or Brachiaria spp. planted as a border around the cereal-legume intercrop. The plants accompanying the cereal crop are typically valuable high quality fodder thus integrating crop-livestock production. The PPT was initially developed in the high altitude areas which were mainly suitable for optimal growth of Desmodium sp. In contrast, Clitoria ternatea (Blue pea) is the recommended herbaceous forage legume crop for the low altitude areas. In addition, clitoria and dolichos demonstrated their ability to effectively repel stem-borer pests in push pull technology systems within the coastal lowlands. The experiments were established in four sites representing diverse coastal lowlands (CL) agro-ecological zones (CL3, CL4, and CL5). The species used in the system were: maize (cereal crop, the main target by Spodoptera pests); climate-smart brachiaria grass (as a pull crop) and blue pea (as a push crop). It was demonstrated that the push-pull technology can also control FAW and that this system be promoted for provision of high quality fodder for livestock in smallholder mixed farms

In vitro anti-viral activity of aqueous extracts of Kenyan Carissa edulis , Prunus africana and Melia azedarach against human cytomegalovirus

The aqueous extracts of three medicinal plants, Carissa edulis (Forssk.) Vahl (Apocynaceae), Prunus africana (Hook.f.) Kalkm (Rosaceae) and Melia azedarach L. (Meliaceae) have shown significant reduction in the replication of human cytomegalovirus (HCMV) in human embryonic lung (HEL) fibroblasts cells in vitro. Using the plaque inhibition assay for the determination of anti-viral activity, the HEL fibroblast cells cultured in 24 well plates were infected with 1 x 102 PFU 91S HCMV and treated with various concentrations of the extracts. The plaques formed were counted after 7 days incubation at 37\ub0C in 5% CO2 and the percent plaques inhibited were calculated against infected untreated control. The effective concentrations inhibiting plaque formation by 50% (EC50) was found between 40 to 80 \u3bcg/ml for all the extracts. The cell cytotoxic concentrations (CC50) for each of the three extracts, by the trypan blue exclusion test, gave a safe therapeutic index. These results have demonstrated the potential anti-viral activities of the extracts of the three medicinal plants at non-cytotoxic concentrations

Limited duration of vaccine poliovirus and other enterovirus excretion among human immunodeficiency virus infected children in Kenya

<p>Abstract</p> <p>Background</p> <p>Immunodeficient persons with persistent vaccine-related poliovirus infection may serve as a potential reservoir for reintroduction of polioviruses after wild poliovirus eradication, posing a risk of their further circulation in inadequately immunized populations.</p> <p>Methods</p> <p>To estimate the potential for vaccine-related poliovirus persistence among HIV-infected persons, we studied poliovirus excretion following vaccination among children at an orphanage in Kenya. For 12 months after national immunization days, we collected serial stool specimens from orphanage residents aged <5 years at enrollment and recorded their HIV status and demographic, clinical, immunological, and immunization data. To detect and characterize isolated polioviruses and non-polio enteroviruses (NPEV), we used viral culture, typing and intratypic differentiation of isolates by PCR, ELISA, and nucleic acid sequencing. Long-term persistence was defined as shedding for ≥ 6 months.</p> <p>Results</p> <p>Twenty-four children (15 HIV-infected, 9 HIV-uninfected) were enrolled, and 255 specimens (170 from HIV-infected, 85 from HIV-uninfected) were collected. All HIV-infected children had mildly or moderately symptomatic HIV-disease and moderate-to-severe immunosuppression. Fifteen participants shed vaccine-related polioviruses, and 22 shed NPEV at some point during the study period. Of 46 poliovirus-positive specimens, 31 were from HIV-infected, and 15 from HIV-uninfected children. No participant shed polioviruses for ≥ 6 months. Genomic sequencing of poliovirus isolates did not reveal any genetic evidence of long-term shedding. There was no long-term shedding of NPEV.</p> <p>Conclusion</p> <p>The results indicate that mildly to moderately symptomatic HIV-infected children retain the ability to clear enteroviruses, including vaccine-related poliovirus. Larger studies are needed to confirm and generalize these findings.</p

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

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

Investigating the Influence of Stereotype in Intercultural Communication Towards English Literature Students of Universitas Muslim Indonesia

This study's objectives explored two prominent cases: (1) the forms of stereotype in Literature Faculty and (2) how the influence of stereotype in intercultural communication toward the students of Literature Faculty. This study applied qualitative research, which explored the stereotype and intercultural communication toward Literature Faculty students. The researcher applied purposive sampling to gain data. There were 15 students participated as the participant, and the data were obtained through interviews. This study shows that stereotypes in Literature Faculty were stereotypes towards Makassar Ethnicity (Rudely) and stereotypes towards Buginese (Uang Panaik it is too expensive). Even though the students learned many negative stereotypes toward Makassarese and Buginese, most students were not affected by these negative stereotypes. The students chose to trust personal experience and establish effective communication with Makassarese and Buginese, which eventually eliminated negative stereotypes towards the Makassarese and Buginese groups

Assessment of Bacteriological and Physico-chemical Qualities of Stand-pipe Drinking Water Stored in Huruma Food Kiosks of

A total of 104 water samples were randomly taken and analyzed to determine bacteriological and physico-chemical qualities of stand-pipe drinking water stored in Huruma food kiosks of Nairobi, Kenya. Out of these, 92 were from storage containers and 12 from stand-pipes supplying the food kiosks. The mean sample temperature ranged from 19.19°C to 23.0ºC, while the mean pH ranged from 6.75 to 7.0. All samples analyzed in this study had a residual chlorine level of 0.5 mg/l. The mean total bacterial count (TBC) for stand-pipe samples was 46 per ml, while that from stored water was 615 per ml. The mean coliform count was 7 and 64 per 100 ml for stand-pipes and stored water respectively. Faecal streptococci had mean counts of 13 and 55 per ml in stand-pipes and stored water respectively. Feacal coliforms were isolated from 2 (17%) stand-pipes and 43 (47%) stored water. Faecal streptococci was isolated from 2 (17%) and 57 (62%) stand-pipes and stored water samples respectively. A significant difference in TBC between stand-pipe and stored water (t = -4.379, df = 102, p = 0.001) was noted. Questionnaire and observation investigations revealed that 82(90%) of Kiosk workers treated their drinking water on request. Some water scooping vessels were found lying on dirty floor outside and near open drainage systems. In conclusions results from this study indicates a high risk of infections with pathogens to the consumers. It is therefore recommended that drinking water be treated before consumption. Kenya Veterinarian Vol. 31 (1) 2007: pp. 26-3