Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Environmental and Management Factors that Influence Commelina Species in Selected Agro-Ecological Zones in Western Kenya

Abstract/Overview Commelina species are plant resources full of promise as future food and feed that thrive in diverse ecosystems. They are medicinal plants, leafy vegetables, forage for ruminants, feed for cricket insects, crop protection, and fuel. However, information regarding factors driving Commelina in agro-ecological zones in Western Kenya is lacking. Therefore, we investigated the diversity of Commelina species, the composition of associated weed species as well as environmental ...

Strategies for Mitigating Flood Risks in Western Region, Kenya

Abstract The focus on strategies for mitigating flood risks is to identify which measures have been put in place to reduce flood risk using nature-based affordable approaches. It has been observed that there is a continuous increase in floods all over the world, in developed and developing countries, as a result of climate change. Floods have affected millions of people worldwide, leading to environmental, physical, economic, and social losses and reducing the growth of the nation. Disaster ...

Profiles of bacterial communities and environmental factors associated with proliferation of malaria vector mosquitoes within the Kenyan Coast

Abstract Background. Since Anopheles mosquitoes which transmit and maintain the malaria parasite breed in the outdoor environment, there is an urgent need to manage these mosquito breeding sites. In order to elaborate more on the ecological landscape of mosquito breeding sites, the bacterial community structure and their interactions with physicochemical factors in mosquito larval habitats was characterised in Kwale County (Kenya), where malaria is endemic. Methods. The physical characterist...

Total electron content and scintillations over Maseno, Kenya, during high solar activity year

Abstract Proper characterization of total electron content (TEC) and scintillation is very important to global positioning system (GPS) users in communication, navigation, ionospheric or atmospheric studies. Quiet time variation of TEC is useful in the estimation and removal of ionospheric delay for global navigation satellite systems single-frequency positioning. During geomagnetic storms, the variations of ionosphere deviate from their quiet day pattern and can cause significant effects on...

Electrical and Structural Properties of Aluminium Doped tin Oxide Codoped with Sulphur for Solar Energy

Abstract Thin films of Tin Oxide co-doped with 28 atomic percentages of Aluminium (i.e. 28 at% Al) and varied concentration of Sulphur were prepared on 1mm thick, 1cm by 1cm glass substrates at 470 0C by Spray Pyrolysis technique. Films were produced from 2.0M solution of hydrous Tin Chloride dissolved in Ethanol with 38% Hydrochloric acid concentration, 1.5M aqueous Aluminium chloride and 2.0M aqueous solution of Ammonium Sulphide. The effects of Sulphur concentration on structural and elec...

Education for Sustainable Development: The Case of Masinde Muliro University of Science and Technology (MMUST

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...

Tuning the reactivity of ruthenium(II) terpyridyl complexes using auxiliary ligands: kinetic and mechanistic studies

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...

Insecticide resistant Anopheles gambiae have enhanced longevity but reduced reproductive fitness and a longer first gonotrophic cycle

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...

Prospects for the Development of Odour Baits to Control the Tsetse Flies Glossina tachinoides and G. palpalis s.l.

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 ...

Prospects for Developing Odour Baits To Control Glossina fuscipes spp., the Major Vector of Human African Trypanosomiasis.

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 ...

Prospects for Developing Odour Baits To Control Glossina fuscipes spp., the Major Vector of Human African Trypanosomiasis

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 ...

Insecticide resistance exerts significant fitness costs in immature stages of Anopheles gambiae in western Kenya

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 ...

Potential tropical climate-based spatio-temporal grass variability

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...

A new gnidiflavanone-flavonol dimer and other constituents from Gnidia apiculata

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...

Education for Sustainable Development: The Case of Masinde Muliro University of Science and Technology (MMUST)

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...


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