Biological Science Research Papers/Topics

Dynamics of mosquito species (diptera: culicidae): implications on vector management and malaria prevalence under globalclimate change

Abstract: Malaria is considered the main cause of morbidity and mortality in most countries of the sub- Saharan Africa. Though elimination of the disease is a priority in some African countries such as Botswana, there are bottlenecks that make it difficult to achieve such target. Factors associated with the environment and mosquito-vector capacity for disease transmission have contributions towards challenges affecting disease elimination. These are dynamics which have not been explored in t...

Assessment of airborne bacterial diversity and antibiotic resistance patterns in hospitals, public transport and wastewater treatment plants in Botswana

Abstract: There is presently insufficient information on the atmospheric microbial level in Botswana, the occurrence and diversity of airborne microbes in Botswana is not well understood. In addition, there is also growing concern in the global spread of antimicrobial resistant bacterial pathogens that continue to emerge and pose a huge challenge to human health. This study, being the first of its kind in the country was aimed at understanding the occurrence, distribution and relative divers...

Assessing the impact of wastewater irrigation on the dynamics of antibiotic resistance in agricultural setting

Abstract: Water scarcity is one of the main challenges in sustainable development particularly in developing countries. The use of wastewater effluent for irrigation of crops is common in most water-stressed countries as this alleviates pressure on fresh water supply. Wastewater treatment plants (WWTPs) are regarded as hotspots for antibiotic resistance determinants; antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and mobile genetic elements (e.g. plasmids). These ant...

Microbiological and physico-chemical characterization of khadi, a traditional non-cereal based alcoholic beverage of Botswana

Abstract: Khadi is a traditional fermented alcoholic beverage popular in Botswana. There is little documented information about the brewing processes, the microorganisms responsible for fermentation as well as the safety despite its popularity in local markets. Such information is vital for production of a standardized beverage with a consistent quality to aid its entrance into the modern commercial markets. This thesis explored the brewing processes, microbiological quality and safety, as i...

Dung beetles’ responses to changing environments; implications on ecosystem service delivery

Abstract: Dung beetles are coprophagous insects belonging to the families Scarabaeidae and Geotrupidae. They are a very important insects’ group, acting as significant ecosystem engineers through dung burial, decomposition, nutrient cycling, bioturbation and seed dispersal in natural and human managed systems. Despite these benefits, most essential ecosystem services are not economically quantified and as such, their roles as natural capital in natural and human managed systems have la...

Integrated pest management: the push-pull approach forcontrolling insect pests and weeds of cereals, and its potential for other agricultural systems including animal husbandry

Abstract: This paper describes the ‘push–pull’ or ‘stimulo-deterrent diversionary’ strategy in relation to current and potential examples from our own experiences. The push–pull effect is established by exploiting semiochemicals to repel insect pests from the crop (‘push’) and to attract them into trap crops (‘pull’). The systems exemplified here have been developed for subsistence farming in Africa and delivery of the semiochemicals is entirely by companion cropping, i.e...

Reproductive compatibility of several East and West African Cotesia Sesamiae (Hymenoptera: Braconidae) Populations and their Crosses and Backcrosses using Sesamia calamistis (Lepidoptera: Noc

Abstract: The relative importance of the braconid Cotesia sesamiae, a gregarious larval parasitoid of lepidopteran stemborers, varies greatly with region in Africa; while the most common parasitoid of noctuid stemborers in eastern Africa, it is rare in western Africa. Thus, several strains of C. sesamiae from Kenya are envisaged for introduction into western Africa. The present study investigates the reproductive compatibility between four populations of C. sesamiae from West Africa and Keny...

Virulence of the Entomopathogenic Fungi Beauveria Bassiana and Metarhizium Anisopliae to Sweet Potato Weevil Cylas Puncticollis and Effects on Fecundity and Egg Viability

Abstract: The virulence of eight isolates of Metarhizium anisopliae and four isolates of Beauveria bassiana (Ascomycota: Hypocreales) to adult Cylas puncticollis (Coleoptera: Curculionidae) was tested in the laboratory. Insects were sprayed with a standard concentration of 1.0 107 conidia mL21 using Burgerjon’s spray tower. All the isolates tested were pathogenic to C. puncticollis. Mortality varied between 77.5% and 84.2% with isolates of B. bassiana and between 62.5% and 89.2% with isola...

Landscape Effects on Crop Pollination Services: are there General Patterns?

Abstract: Pollination by bees and other animals increases the size, quality, or stability of harvests for 70% of leading global crops. Because native species pollinate many of these crops effectively, conserving habitats for wild pollinators within agricultural landscapes can help maintain pollination services. Using hierarchical Bayesian techniques, we synthesize the results of 23 studies – representing 16 crops on five continents – to estimate the general relationship between pollinati...

Geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes Cameron in cultivated and natural habitats in Kenya

Abstract: Field surveys were carried out in four agroecological zones to assess the geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes in cultivated and natural habitats in Kenya.The distribution of the two Cotesia species in different ecological regions was most affected by the suitability of the local stem borer species for parasitoid development, and temperature, as both species were found in localities dominated by their suitable host(s) where te...

Differential Expression of the CrV1 Haemocyte Inactivation-associated Polydnavirus gene in the African Maize Stem borer Busseola fusca (Fuller) Parasitized by Two Biotypes of the Endoparasito

Abstract: Polydnaviruses are rarely studied for their natural variation in immune suppressive abilities. The polydnavirus harboring braconid Cotesia sesamiae, a widespread endoparasitoid of Busseola fusca and Sesamia calamistis in sub-Saharan Africa exists as two biotypes. In Kenya, the western biotype completes development in B. fusca larvae. However, eggs of the coastal C. sesamiae are encapsulated in this host and ultimately, no parasitoids emerge from parasitized B. fusca larvae. Both bi...

Antibacterial Activity of Apis mellifera L. propolis Collected in Three Regions of Kenya

Abstract: The present study aimed at investigating the susceptibility of the microorganisms Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis to ethanolic extracts of propolis (EEP) from three regions of Kenya (Taita, Tana and Samburu). Propolis was extracted using four different concentrations of ethanol: pure, 70%, 50%, and 30%. Ethanol (70%) and Streptomycin were used as controls. The agar diffusion method using filter paper disks was...

Convergent Evolution of eye Ultrastructure and Divergent Evolution of Vision-mediated Predatory Behaviour in Jumping Spiders

Abstract: All jumping spiders have unique, complex eyes with exceptional spatial acuity and some of the most elaborate vision-guided predatory strategies ever documented for any animal of their size. However, it is only recently that phylogenetic techniques have been used to reconstruct the relationships and key evolutionary events within the Salticidae. Here, we used data for 35 species and six genes (4.8 kb) for reconstructing the phylogenetic relationships between Spartaeinae, Lyssomanina...

Transferability of tsetse habitat models between different regions in Kenya and Rwanda

Abstract: Accurate and reliable information on the distribution of tsetse habitats is crucial for the effective management of African Trypanosomiasis in sub-Saharan Africa. However, conducting large-scale surveillance of tsetse flies to develop distribution maps is impractical due to vast areas infested and limited resources available. To address this challenge, we evaluated the applicability of tsetse habitat models developed in the intensively sampled Shimba Hills National Reserve in Kenya...

An Exploratory Study of Community Factors Relevant for Participatory Malaria Control on Rusinga Island, western Kenya

Abstract: Background: Capacity strengthening of rural communities, and the various actors that support them, is needed to enable them to lead their own malaria control programmes. Here the existing capacity of a rural community in western Kenya was evaluated in preparation for a larger intervention. Methods: Focus group discussions and semi-structured individual interviews were carried out in 1,451 households to determine (1) demographics of respondent and household; (2) socio-economic statu...


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