Abstract Substitution behavior of the labile aqua ligand in four mononuclear ruthenium(II) terpyridyl complexes with different auxiliary N (pyridine) (Ru1), N^N (2,2′-bipyridyl (Ru2), 2′-(2-pyridyl)quinoline (Ru3), 2,2′-biqunoline (Ru4) ligands was investigated using three nucleophiles; thiourea, 1,1-dimethylthiourea and 1,1,3,3-tetramethylthiourea. The effect of concentration and temperature on the substitution behavior of the complexes were studied under pseudo-first order conditions...
Abstract Widespread insecticide resistance in African malaria vectors raises concerns over the potential to compromise malaria vector control interventions. Understanding the evolution of resistance mechanisms, and whether the selective disadvantages are large enough to be useful in resistance management or designing suitable control strategies is crucial. This study assessed whether insecticide resistance to pyrethroids has an effect on the gonotrophic cycle and reproductive potential of ma...
Abstract Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (∼5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent ...
Abstract We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed ...
Abstract We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed ...
Abstract Background Despite increasing documentation of insecticide resistance in malaria vectors against public health insecticides in sub-Saharan Africa, there is a paucity of information on the potential fitness costs of pyrethroid resistance in malaria vectors, which is important in improving the current resistant management strategies. This study aimed to assess the fitness cost effects of insecticide resistance on the development and survival of immature Anopheles gambiae from western ...
Abstract Numerous international agreements aimed at reduction of greenhouse gas emissions by signatory countries have been ratified in an attempt to combat the adverse varied impacts of climate change and promote resource use sustainability. Grass is an important resource that livestock, wildlife and human beings depend on and is largely influenced by climatic conditions. The grass in Kenya supports the key economic activities of livestock and wildlife-based tourism. This significant contrib...
Abstract A new 3,8′′-flavanone-flavonol dimer gnidiflavanone-flavonol (1) and 10 known compounds (2–11), including four rare primula-type flavones 2–5, were isolated from the roots of Gnidia apiculata. Compounds 2–5 and 7 were reported for the first time from the plant family Thymelaeceae. Structures of the isolated compounds were established by spectroscopic data, including 1D and 2D NMR (COSY, HMBC, HSQC and ROESY) and mass spectrometry, as well as by the comparison with literatu...
Abstract The unit-based sustainability assessment tool (USAT) was administered at Masinde Muliro University of Science and Technology (MMUST), Kenya, between January and March 2012. The assessment focused on establishing to what extent the University integrated sustainability concerns into its core functions of teaching, research and community engagement. Using a unit-based assessment tool allowed for ‘building the picture’ of the whole university, as well as concentrating on specific un...
Abstract The fate and transport of Escherichia coli (E. coli) in lotic waters through vegetated filter strips (VFSs) was evaluated in a field model pasture, utilizing VFSMOD Windows along with direct pathogen testing. This study assessed effects of VFS on transport and deposition rates of E. coli in lotic overland flow waters. The VFS measured 44 m long by 40 m wide, covering an area of 1584 m2 and land slope of 15 %. Cowpat was applied onto the model pasture and washed by overland flow into...
Abstract Communicating climate change remains an integral aspect of the quest to manage the impacts of climate change. Communicating climate change largely takes the western scientific approach without much consideration of African traditional knowledge. Communicating climate change has not elicited the desired response from the community that lives adjacent to Kakamega Forest. Abaluhyia people have had ways of conserving their forests, which ensured their posterity. The study aimed to asses...
Abstract Paraoxon is an emerging organophosphate pollutant that is commonly used as a pesticide and a drug, hence increasing the risk of contamination of water supplies. Its intensive use for vector control has led to pollutions in soil and water. Paraoxon is very toxic, with an LD50 of 2 to 30 mg/kg in rats. It can be metabolized in the body from parathion; thus, exposure can lead to serious health effects. In this study, zero valent iron (Fe°/ZVI NPs) nanoparticles were synthesized and in...
Abstract/Overview The full-scale impact of odour-baited technology on the surveillance, sampling and control of vectors of infectious diseases is partly limited by the lack of methods for the efficient and sustainable dispensing of attractants. In this study we investigated whether locally-available and commonly used textiles are efficient substrates for the release of synthetic odorant blends attracting malaria mosquitoes. METHODS The relative efficacy of (a) polyester, (b) cotton, (c) c...
Abstract There is still unexplored reservoir of microorganisms from sediments and water within Lakes Olbolosat and Oloiden using culture dependent technique. The current study compares bacterial diversity within Lake Olbolosat a freshwater lake and Lake Oloiden a saline alkaline lake. Out of 60 isolates obtained from sediments and water samples, 35 were from Lake Olbolosat and 25 from Lake Oloiden. Microbial count ranged between 0-1.75× 10 5 cfu/ml from both lakes. There was a significant d...
Abstract/Overview The use of odor baits for surveillance and control of malaria mosquitoes requires robust dispensing tools. In this study, the residual activity of a synthetic mosquito attractant blend dispensed from nylon or low density polyethylene (LDPE) sachets was evaluated at weekly intervals for one year without re-impregnation. The potential role of bacteria in modulating the attraction of mosquitoes to odor-treated nylon that had been used repeatedly over the one year study peri...