Makau C.M.,Mount Kenya University |
Towett P.K.,University of Nairobi |
Abelson K.S.P.,Copenhagen University |
Kanui T.I.,South Eastern Kenya University
Journal of Veterinary Pharmacology and Therapeutics | Year: 2016
The study was designed to investigate the involvement of noradrenergic and serotonergic receptor systems in the modulation of formalin-induced pain-related behaviour in the Speke's hinged tortoise. Intradermal injection of 100 μL of formalin at a dilution of 12.5% caused pain-related behaviour (hindlimb withdrawal) that lasted for a mean time of 19.28 min (monophasic response). Intrathecal administration of clonidine (α2-adrenergic receptor agonist) and yohimbine (α2-adrenergic receptor antagonist) at a dose of 40 μg/kg and 37.5 μg/kg or 50 μg/kg, respectively, caused a highly significant reduction in the duration of the formalin-induced pain-related behaviour. The effect of clonidine was reversed by intrathecal administration of yohimbine at a dose of 26.7 μg/kg. The effect of yohimbine at a dose of 50 μg/kg was reversed by intrathecal injection of 20 μg/kg of the serotonergic receptor antagonist methysergide maleate. When performing antagonistic reactions, the administration of the antagonist was followed immediately by that of the agonist. The study indicates that for experimental purposes, intrathecal route of drug administration through the atlanto-occipital joint is effective in tortoises. The data also suggest that testudines have noradrenergic and serotonergic systems that appear to play a role in the modulation of pain in this species. 2016 John Wiley & Sons Ltd.
Kaluwa Kaingu C.,University of Nairobi |
Oduma J.A.,University of Nairobi |
Kanui T.,South Eastern Kenya University
Journal of Ethnopharmacology | Year: 2012
Ricinus communis and Euclea divinorum of the family Euphorbiaceae and Ebenaceae, respectively, are traditionally used by Traditional Birth Attendants (TBAs) in Machakos district of Kenya to induce or augment labor, manage protracted labor, post-partum hemorrhage and retained after birth. Ethno-pharmacological relevance of the study will be the provision of scientific evidence and justification for the ethnic use of both plants as oxytocic agents in the initiation of labor, treatment of prolonged labor, post-partum hemorrhage and retained placenta. Materials and methods: The plants were harvested in the wild, identified and voucher specimens preserved. The root bark was processed to powder form, from which aqueous and ethanol extracts were obtained. Each of the extracts was separately tested on isolated uterine muscle tissue from non-pregnant and pregnant rabbits. The effect on contraction frequency (number of contractions per second) in the absence or presence of oxytocin was evaluated statistically using ANOVA. P values <0.05 were considered significant. Results and conclusions: All uteri exhibited a strong initial contraction following exposure to the aqueous and ethanol root bark extracts of both plants. After recovery, the resumed contraction frequencies varied with the plant extract and exogenous hormone. The results show that the extracts of both plants were able to stimulate uterine tissue contractility directly and to augment the tissues response to oxytocin. The increase in uterine contractions as a percentage relative to negative controls was particularly significant in pregnant rabbit tissues in the presence of oxytocin, where increments of up to 245% were observed. Further pharmacological studies are however required to determine the active principles, possible mechanisms of action, efficacy and safety margins of the plant extracts. © 2012 Elsevier Ireland Ltd.
Pfeiffer E.J.,Butler University |
Maithya H.M.K.,South Eastern Kenya University
Global Public Health | Year: 2016
Since access to HIV testing, counselling, and drug therapy has improved so dramatically, scholars have investigated ways this ‘scale-up’ has interacted with HIV/AIDS-related stigma in sub-Saharan Africa. Drawing on data collected during ethnographic research in a trading centre in western Kenya, this paper critically analyses two violent and localised case studies of panic over the ill health of particular community residents as a nuanced lens through which to explore the dynamic interplay of gender politics and processes of HIV/AIDS-related stigma in the aftershocks of the AIDS crisis. Gaining theoretical momentum from literatures focusing on stigma, gender, witchcraft, gossip, and accusation, we argue that the cases highlight collective anxieties, as well as local critiques of shifting gender roles and the strain of globalisation and legacies of uneven development on myriad forms of relationships. We further contend that these heightened moments of panic and accusation were deployments of power that ultimately sharpened local gender politics and conflicts on the ground in ways that complicated the social solidarity necessary to tackle social and health inequalities. The paper highlights one community’s challenge to eradicate the stigma associated with HIV/AIDS during a period of increased access to HIV services. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Gikuma-Njuru P.,University of Waterloo |
Gikuma-Njuru P.,South Eastern Kenya University |
Hecky R.E.,University of Minnesota |
Guildford S.J.,University of Minnesota |
Macintyre S.,University of California at Santa Barbara
Limnology and Oceanography | Year: 2013
Measurements of nutrient concentrations and physicochemical parameters were carried out monthly between March 2005 and March 2006 along a transect between the Nyanza Gulf and the open waters of Lake Victoria to evaluate spatial and seasonal variations in nutrient fluxes and ecosystem metabolism. Nutrient concentration gradients were observed between the deep and seasonally stratifying main lake basin and the large, shallow riverinfluenced Nyanza Gulf, which are connected by the relatively deep and narrow Rusinga Channel. Nutrient gradients were steepest in the Rusinga Channel where there was always a strong gradient in electrical conductivity. A mixing-box model used to quantify nutrient fluxes and ecosystem metabolism along the gulf and the channel showed that nutrients entering the gulf through river inflows and municipal sources were largely retained in the gulf, with only a small fraction transferred into the main lake. In contrast, the main lake was a net exporter of dissolved inorganic phosphorus to the gulf (110 mg P m-2 yr-1), which is in contrast to the paradigm that the gulf is a major contributor to the increasing nutrient enrichment and, hence, eutrophication of the greater Lake Victoria. The channel had net regeneration of dissolved nutrients indicating net heterotrophy; whereas in the gulf, there was net consumption of dissolved nutrients, resulting in high estimates of net ecosystem production (570 mg C m-2 yr-1) and, hence, net autotrophy. Nitrogen balance ranged from +3 to +15 mg N m-2 yr-1, indicating dominance of nitrogen fixation over denitrification in both the gulf and the channel, which are both well-oxygenated.
Mathooko F.M.,South Eastern Kenya University |
Mutui T.M.,South Eastern Kenya University
Acta Horticulturae | Year: 2011
The Kenyan horticulture industry has grown to become a major employer contributor to food needs and foreign exchange earner. Horticulture is the second largest earner of foreign exchange after remittances from Kenyan Diaspora. In Kenya public sector horticultural research is conducted by public universities and the Kenya Agricultural Research Institute (KARI) as a public good. Challenges in postharvest (PH) horticulture research and training include inadequate funding (<5%), poor research infrastructure, shortage of trained PH manpower, low student enrolment, limited access to current literature and inadequate policies. Slow bureaucratic procedures in public institutions undermine their ability to respond to urgent farmers' needs of low-cost PH technologies adaptable to different regions. Also, natural science researchers need better social science skills for technology transfer from laboratories to farms. Opportunities in PH research and training in Kenya include schools of agriculture in universities offering horticulture, postharvest physiology and technology, food technology and processing. Activities for development of adequate PH capacity include training, education, extension and technology transfer. Because of very limited resources, PH research is directed towards specific problems and 'knowledge-generation'. Kenya has a well-developed and dynamic private horticulture sector which presents an ideal investment opportunity with ready markets for produce. A successful approach to maximize PH research and training input would be development of programs with public-private partnerships having evolving roles. Moreover, the growing importance of environmental concerns presents opportunities and challenges for PH research. Rather than concentrating on isolated topics such as storage technology, emphasis on the whole PH value chain system can help in identifying bottlenecks, constraints and investment opportunities in order to increase the impact of PH research and training in horticulture.
Kavembe G.D.,University of Konstanz |
Kavembe G.D.,South Eastern Kenya University |
Kautt A.F.,University of Konstanz |
Machado-Schiaffino G.,University of Konstanz |
Meyer A.,University of Konstanz
Molecular Ecology | Year: 2016
Ecological diversification through divergent selection is thought to be a major force during the process of adaptive radiations. However, the large sizes and complexity of most radiations such as those of the cichlids in the African Great Lakes make it impossible to infer the exact evolutionary history of any population divergence event. The genus Alcolapia, a small cichlid lineage endemic to Lakes Magadi and Natron in East Africa, exhibits phenotypes similar to some of those found in cichlids of the radiations of the African Great Lakes. The simplicity within Alcolapia makes it an excellent model system to investigate ecological diversification and speciation. We used an integrated approach including population genomics based on RAD-seq data, geometric morphometrics and stable isotope analyses to investigate the eco-morphological diversification of tilapia in Lake Magadi and its satellite lake Little Magadi. Additionally, we reconstructed the demographic history of the species using coalescent simulations based on the joint site frequency spectrum. The population in Little Magadi has a characteristically upturned mouth - possibly an adaptation to feeding on prey from the water surface. Eco-morphological differences between populations within Lake Magadi are more subtle, but are consistent with known ecological differences between its lagoons such as high concentrations of nitrogen attributable to extensive guano deposits in Rest of Magadi relative to Fish Springs Lagoon. All populations diverged simultaneously only about 1100 generations ago. Differences in levels of gene flow between populations and the effective population sizes have likely resulted in the inferred heterogeneous patterns of genome-wide differentiation. © 2015 John Wiley & Sons Ltd.
Kimiti J.M.,South Eastern Kenya University
African Journal of Agricultural Research | Year: 2011
The effect of integrated soil fertility management (ISFM) on root growth of selected cowpea varieties in two sites with contrasting rainfall amounts over two seasons was investigated. Nine cowpea varieties were used as test crop and the treatments applied include a control, farmyard manure at 2.5 t ha -1,triplesuperphosphate (TSP) at 15 kg ha -1 as (P2O5, 0:46:0), and TSP mixed with farmyard manure at the singly applied rates. The experiment was laid down as a split plot design and it was replicated three times. Data collected include root and shoot biomass at 50% flowering, and shoot biomass at crop maturity. In addition, root to shoot ratios at 50%, correlations between root biomass and shoot biomass at 50% flowering, and correlations between root biomass at 50% flowering and shoot biomass at crop maturity were also determined. The data were analysed as a split plot design using GenStat for Microsoft windows. Results obtained revealed that addition of nutrient inputs enhanced root biomass at Ndunguni during both the long and short rains and only in two treatments at Kavuthu during the short rains. However, addition of nutrients relatively lowered root: shoot ratios in most treatments in both study sites during the two seasons indicating phosphorus (P) deficiency in the study sites. Furthermore, strong positive and significant (p < 0.05) correlations between root and shoot iomass were recorded during the long rain season which was relatively dry compared to the short rain season, indicating the dependence of shoot growth on root growth under limiting moisture conditions. These results revealed the need to add nutrients, especially P, to enhance cowpea root growth and the importance of moisture in root and shoot growth in the drylands. © 2011 Academic Journals.
Alexander R.,University of Western Australia |
Gikuma-Njuru P.,South Eastern Kenya University |
Imberger J.,University of Western Australia
Limnology and Oceanography: Methods | Year: 2012
Rapid in situ measurements of some components of fluorescent spectra are now possible with submersible multi-wavelength fluorometers, which implies that phytoplankton composition can be measured, at least implicitly, at a spatial resolution that allows many scales of patches to be resolved. We present a method for identifying the location of patches of distinct fluorescent groupings of phytoplankton by using principal component analysis (PCA) to process in situ spectral data. The processing method potentially allows retention of more information from the raw data than existing methods because it depends on fewer assumptions. Furthermore, it can be applied without the need for site-specific calibration of the fluorometer. A series of idealized spectral data sets were used to explain the conceptual basis of the approach; the method was then applied to field spectral data sampled in Lake Victoria, Kenya. The results demonstrate that the main features of large sample sets of multi-component spectral data can be summarized in a single graph that reveals the number of spectrally distinct groups of phytoplankton at the site, and allows information about the spatial structure of those different phytoplankton groups to be derived from subsequent analysis. In this way, fluorescent spectral data collected at high spatial resolution can be used to identify the locations of patches and facilitate targeted water sample collection from those locations to investigate the species diversity and distribution at a study site. © 2012, by the American Society of Limnology and Oceanography, Inc.
Johnson U.K.,South Eastern Kenya University
Journal of Geographical Sciences | Year: 2013
The paper presents results of a study on the sediment supply and movement of highly turbid sediment plume within Malindi Bay in the Northern region of the Kenya coast. The current velocities, tidal elevation, salinity and suspended sediment concentrations (TSSC) were measured in stations located within the bay using Aanderaa Recording Current Meter (RCM-9), Turbidity Sensor mounted on RCM-9, Divers Gauges and Aanderaa Temperature-Salinity Meter. The study established that Malindi Bay receives a high terrigenous sediment load amounting to 5. 7 × 106 ton·yr-1. The river freshwater supply into the bay is highly variable ranging from 7 to 680 m3·s-1. The high flows that are > 150 m3·s-1 occurred in May during the South East Monsoon (SEM). Relatively low peak flows occurred in November during the North East Monsoon (NEM) but these were usually <70 m3·s-1. The discharge of highly turbidity river water into the bay in April and May occurs in a period of high intensity SEM winds that generate strong north flowing current that transports the river sediment plume northward. However, during the NEM, the river supply of turbid water is relatively low occurring in a period of relatively low intensity NEM winds that result in relatively weaker south flowing current that transports the sediment plume southward. The mechanism of advection of the sediment plume north or south of the estuary is mainly thought to be due to the Ekman transport generated by the onshore monsoon winds. Limited movement of the river sediment plume southward towards Ras Vasco Da Gama during NEM has ensured that the coral reef ecosystem in the northern parts of Malindi Marine National Park has not been completely destroyed by the influx of terrigenous sediments. However, to the north there is no coral reef ecosystem. The high sediment discharge into Malindi Bay can be attributed to land use change in the Athi-Sabaki River Basin in addition to rapid population increase which has led to clearance of forests to open land for agriculture, livestock grazing and settlement. The problems of heavy siltation in the bay can be addressed by implementing effective soil conservation programmes in the Athi-Sabaki Basin. However, the soil conservation programmes in the basin are yet to succeed due to widespread poverty among the inhabitants and the complications brought about by climate change. © 2013 Science Press and Springer-Verlag Berlin Heidelberg.
Mganga K.Z.,University of Gottingen |
Mganga K.Z.,South Eastern Kenya University |
Kuzyakov Y.,University of Gottingen
European Journal of Soil Biology | Year: 2014
Land use change can affect terrestrial C stocks, resulting in increased CO2 flux from soil to the atmosphere. In Africa, conversion of natural ecosystems to agricultural lands is the most common land use change. This study investigated the effects of six land use types occurring in Mt. Kilimanjaro ecosystems i.e. (1) lower montane forest (2) grassland and (3) savannah (natural ecosystems) (4) Chagga homegardens (semi-natural ecosystem) and (5) maize fields and (6) coffee plantation (agroecosystems) on microbial biomass carbon (MBC) and dynamics of 14C labelled glucose added into soil. Decomposition of 14C labelled glucose and its incorporation into microbial biomass in surface soils (0-10 and 10-20cm) were determined. MBC decreased significantly with increased intensity of land use. Mineralization of the 14C labelled glucose occurred in two phases with contrasting rates: 0-10 days (6-18% of 14C d-1) and 15-65 days (<0.1% of 14C d-1). Land use intensification in agroecosystems led to an average increase of glucose decomposition of 14%. The decay rates of the labile C pool in intensively used agricultural lands were up to three times higher compared to natural ecosystems. The incorporation of 14C glucose into microorganisms ranged between 1 and 7% of 14C input in all soils, and was highest in savannah. Agricultural intensification decreased C content in soil through increased mineralization of organic substances and negatively impacted the upper soil layer more compared to the lower one. Based on these results we conclude that semi-natural ecosystems (e.g. Chagga homegardens) are more sustainable in Mt. Kilimanjaro ecosystems compared to intensive agroecosystems. © 2014 Elsevier Masson SAS.