Faculty of Applied Science and Technology

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Adsorption Studies of Trimethoprim Antibiotic on Powdered and Granular Activated Carbon in Distilled and Natural Water
(IJSRSET, 2018) Nose, Holiness M.; Opanga, Michael A.; Madadi, Vincent O.; Wandiga, Shem O.; Mirikau, Charles W.; Umuro, Mamo
Contamination of drinking water sources by Pharmaceuticals and Personal Care Products (PPCPs) has raised concerns due to associated negative effects on the ecosystem, which include reproductive and hormonal malfunctions in some living organisms. In addition, occurrence of antibiotics in aquatic environment has been associated with development of antimicrobial resistance. However, the conventional water and wastewater treatment technologies are not effective at removing such organic micro-pollutants from the source waters, hence most of such contaminants find their way through the systems with minimal restrain. Hence accelerated effort to find technologies to enhance removal of recalcitrant organic micro-pollutants from the water and wastewater. The objective of this study was to investigate the removal of Trimethoprim (TMP) from natural water using Powdered Activated Carbon (PAC) and Granular Activated Carbon (GAC). Adsorption experiments were conducted following batch process using natural water and distilled water. We also investigated the effect of pH changes on adsorption of TMP from the water. We obtained better performance for PAC in the removal of TMP compared to GAC. The removal efficiency decreased as a function of TMP concentrations in the aqueous solution. The optimal pH for adsorption was found to be 7, whereas pH values below or above 7 exhibited decreased adsorption of the antibiotic. There was no significant difference in the adsorption of TMP in both natural water and distilled water, which was attributed to limited organic matter in the natural water that was used.
Analysis of Moss and Topsoil to Monitor Metal Emissions from a Pulp and Paper Mill in Western Kenya
(2011) Adoli, Florence K; Lalah, Joseph O; Okoth, Alexander O
The mean concentrations of Zn, Cu, Cd, Cr and FeinmossesaroundWebuyePanPaperfactorywerefound to be signiﬁcantly higher than in controls taken from Kakamega, indicating atmospheric contribution from the anthropogenic activities within the factory, shown within a radius of 1 km around the factory. The mean concentrations (lg/g dry weight) in the mosses ranged from 60.9–124.5, 22.6–34.2, 13.3–14.7, 20.1–33.3 and 1,822.4– 2,079.2, respectively. The mean concentrations of Pb in mosses sampled from the eastern and western side of the factory were also signiﬁcantly higher than in controls. The mean concentrations of Zn, Cu, Cd, Cr, Pb and Fe in topsoil samples ranged from 7 (Pb)–2,310 (Fe) mg/kg dry wt, depending on sample means based on site direction, distance from the factory and season. There was no clear variation in metal concentrations in mosses and topsoils with direction from the factory which was consistent with the observed ﬂuctuations in wind direction which changed from south-west in the mornings to north and south-west in the afternoons during sampling.
Analysis of Moss and Topsoil to Monitor Metal Emissions from a Pulp and Paper Mill in Western Kenya
(Springer, 2010-07-05) Lalah, Joseph O.
The mean concentrations of Zn, Cu, Cd, Cr and Fe in mosses around Webuye Pan Paper factory were found to be significantly higher than in controls taken from Kakamega, indicating atmospheric contribution from the anthropogenic activities within the factory, shown within a radius of 1 km around the factory. The mean concentrations (lg/g dry weight) in the mosses ranged from 60.9–124.5, 22.6–34.2, 13.3–14.7, 20.1–33.3 and 1,822.4– 2,079.2, respectively. The mean concentrations of Pb in mosses sampled from the eastern and western side of the factory were also significantly higher than in controls. The mean concentrations of Zn, Cu, Cd, Cr, Pb and Fe in topsoil samples ranged from 7 (Pb)–2,310 (Fe) mg/kg dry wt, depending on sample means based on site direction, distance from the factory and season. There was no clear variation in metal concentrations in mosses and topsoils with direction from the factory which was consistent with the observed fluctuations in wind direction which changed from south-west in the mornings to north and south-west in the afternoons during sampling.
Anthropogenic Sources of Heavy Metals in the Indian Ocean Coast of Kenya
(Springer Science+Business Media, LLC, 2008-11-28) Lalah, Joseph O.
Water and surface sediment samples from Rivers Sabaki, Ramisi and Vevesi that flow into the Indian Ocean coast of Kenya were analysed for heavy metals. The sediment concentrations of exchangeable cations (in μg/g) for Co, Cu, Mn, Ni, Pb, Sn and Zn ranged from 0.10 to 506.75 (for Mn at Sabaki), constituting between 2% and 20% of the total metal concentrations obtained by digestion with strong acid. Cu, Mn, Ni, Pb and Zn were more leachable with 0.1 N HCl. The total dissolved metal in water and the total sediment concentrations for Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn and Zn are given in the text. For dissolved metals, the metal/Mn ratios indicated higher concentrations of Ag in Sabaki River, Cd in Ramisi, Ni in Sabaki and Pb in Ramisi, respectively. In sediments, the metal/Mn ratios showed higher enrichment of Ag in Ramisi, Cd in Sabaki and Vevesi, and Zn in Sabaki, respectively. Enrichment factors showed elevated levels of Cd, Pb and Zn in sediment in River Sabaki and River Vevesi that were due to anthropogenic inputs through Athi River. The total dissolved metal concentration ranges for the three rivers were comparable with those ranges reported in rivers in South Africa but the sediment concentrations were below those of rivers in Europe and Asia where anthropogenic addition of some of the toxic elements such as Cu, Pb and Cd is evidently higher.
Anti-Schistosomal activity of five plant extracts on Swiss white mice infected with Schistosoma mansoni
(2016-04-13) Waiganjo, Naomi; Yole, Dorcas; Ochanda, Horace
Abstract : Schistosomiasis in humans is a major public health problem worldwide. Schistosomiasis occurs in 76 tropical countries and it is estimated that 85% of the infections are in Africa. In Kenya, it is estimated that 3 million people are infected. The Conventional drugs are effective in the treatment of the disease but very little progress has been achieved on treatment of Schistosomiasis in Kenya. Any effort towards developing alternative drugs for the disease is worthwhile. Praziquantel is the most effective drug against all adult stages of human Schistosomiasis, being the drug of choice for morbidity control of Schistosomiasis. However it is not a satisfying situation to have one drug used for the treatment. Ideally other drugs should be availed in order to avoid development of drug resistance. The use of plant extracts in treatment of diseases is universal. The results obtained showed that Ocimum americanum and Bridelia micrantha plant extracts had antischistosomal activity as indicated by high worm reduction and reduced gross pathology. Histopathology showed no or few granuloma in the liver tissue. Further work should be done on the efficacious extracts, towards drug development.
Antimutagenic effect of Kenyan Tea cultivars in a bacterial test system
(2014) Mbuthia, Karori; Wachira, Francis; Ngure, Raphael; Mireji, Paul O; Wachira, Sabina
The antimutagenic effects of the aqueous tea extracts from Kenyan black, green and purple cultivars were evaluated by the Ames te st using Salmonella typhimurium tester strains TA 1538. Results obtained showed that tea had no toxicity or mutagenic activity at a concentration of 20% (w/v) unlike the mut agen sodium azide. However, using the formulae, percentage inhibition = [1 - T/M] ×10 0 where T is number of revertants per plate in presence of mutagen and test sample and M is number of revertants per plate in positive control, tea extracts had a significant (P<0.05) antimutagenic activity where the percent inhibition was 65% for green te a, 38% for purple tea and 19.17% for black tea. This was attributed to the radical scavenging activity of polyphenols. There is need therefore to carry out further research to help understand the precise mechanism of action especially for black and purple teas, and to explore other beneficial effects that these polyphenols may have, before they can be adopted for therapeutic use.
Application of hydrogeochemical modelling in simulating the transportation of elements in fly ash heap under different disposal systems in South Africa
(2015-07-20) Mbugua, John
Ash heap modelling of South African fly ash from Tutuka was carried out and the duration of transportation projected for 20 years based on two disposal scenarios, namely; irrigation of ash with rainwater, and irrigation with brines. The hydrogeochemical modeling code, PHREEQC, was applied in the study which gave insights into the speciation, release and transport of elements from the water and brines–fly ash long term interactions. Tutuka ash–water heap model showed a general sharp decrease of total elemental concentrations released during the first 2.5 years simulation as the pH value dropped from 12.6 to 8.7, after which it remained constant and their concentration remained constant up to 20 years. The elements showing this trend included Ca, Mg, Al, Fe, Sr, Zn, Na, K, Li and C(4). Generally, brines caused sharp increase in released concentration of the elements Ca, Mg, S(6) and C(4) for the first 3 years of heap irrigation whereas with water irrigation an opposite trend was observed in which the elemental concentrations decreased. Much of the release chemistry of the elements was closely related to the phase dissolution/precipitation and formation as the major controlling factors. Generally therefore, the modelled leachate quality results revealed that many elements are mobile and move through the ash heap in a progressive leaching pathway. The model could therefore be used to provide reasonable leachate quality from the modelled Tutuka ash heap which may be reaching the ground water. Overall, the ash heap modelling enhanced the understanding of the environmental impacts of ash–water–brines interactions and demonstrated that leachate composition is determined by the following factors; (i) the mass flows from the pores of fly ash, (ii) the surface dissolution of the mineral phases, (iii) the various chemical reactions involved during the ash–brine and ash–water interactions, (iv) the interactions with a gas phase (atmospheric CO2), (v) the composition of the initial fly ash, and (vi) the leachate flow and hydrodynamics as captured in the conceptual model. Further model validation is recommended with lysimeters to quantatively compare the simulated results against the experimental data and improve on the model.
Aquaporins Are Critical for Provision of Water during Lactation and Intrauterine Progeny Hydration to Maintain Tsetse Fly Reproductive Success
(2014) Benoit, Joshua B; Hansen, Immo A; Attardo, Geoffrey M; Michalková, Veronika; Mireji, Paul O; Bargul, Joel L; Drake, Lisa L; Masiga, Daniel K; Aksoy, Serap
Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than has been previously documented in any other insect. All organs, tissues, and body parts examined had distinct AQP expression patterns. Two AQP genes, gmmdripa and gmmdripb ( = gmmaqp1a and gmmaqp1b) are highly expressed in the milk gland/fat body tissues. The whole-body transcript levels of these two genes vary over the course of pregnancy. A set of three AQPs (gmmaqp5, gmmaqp2a, and gmmaqp4b) are expressed highly in the Malpighian tubules. Knockdown of gmmdripa and gmmdripb reduced the efficiency of water loss following a blood meal, increased dehydration tolerance and reduced heat tolerance of adult females. Knockdown of gmmdripa extended pregnancy length, and gmmdripb knockdown resulted in extended pregnancy duration and reduced progeny production. We found that knockdown of AQPs increased tsetse milk osmolality and reduced the water content in developing larva. Combined knockdown of gmmdripa, gmmdripb and gmmaqp5 extended pregnancy by 4–6 d, reduced pupal production by nearly 50%, increased milk osmolality by 20–25% and led to dehydration of feeding larvae. Based on these results, we conclude that gmmDripA and gmmDripB are critical for diuresis, stress tolerance and intrauterine lactation through the regulation of water and/or other uncharged solutes.
Assessment of Polycyclic Aromatic Hydrocarbons in Lates niloticus, Oreochromis niloticus and Rastrineobola argentea as Sources of Human Exposure in Kisumu Bay, Winam Gulf of Lake Victoria
(2012) Onyango, Alice A; Lalah, Joseph O; Wandiga, Shem O; Gichuki, John
The concentrations of polycyclic aromatic hydrocarbons (PAHs) in Lates niloticus, Oreochromis niloticus and Rastrineobola argentea from three beaches were assessed to establish whether they are sources of human exposure in Kisumu Bay, Winam Gulf, Lake Victoria, Kenya. O. niloticus had 12 PAHs detected (TPAH 3.93 μg/kg); L. niloticus had 11 (TPAH 3.17 μg/kg). In both cases, the highest and lowest concentrations were Pyrene and Indeno(1,2,3-cd)pyrene, respectively, and the TPAHs were greater than the 2 μg/kg limit allowed by the European Commission although individually they were lower. R. argentea had 2 PAHs (TPAH 0.035 μg/kg). PAH pollution in the Winam Gulf, a potential source of exposure to human through contaminated fish, should be mitigated and safe management practices that reduce PAH levels should be adopted.
Astronomy in the cultural heritage of African societies
(2006) Baki, Paul
The African perspectives of astronomy are explored from the point of view of using indigenous knowledge of the night sky for purposes of addressing local challenges such as food insecurity and periodic natural weather phenomena such as droughts and floods. The local ethnic groups use stellar positions, and plant and animal behaviour changes for purposes of forecasting the weather and climate for the coming seasons. These traditional indicators give rise to an interdisciplinary discourse that could benefit the community in environmental protection measures and boost the tourism industry in some countries in Africa
Behavior of pesticide residues in agricultural soil and adjacent River Kuywa sediment and water samples from Nzoia sugarcane belt in Kenya
(Springer, 2012) Muendo, Boniface M; Lalah, Joseph O; Getenga, Zachary M
An inventory survey conducted to determine pesticide usage in a sub-catchment of the Nzoia sugarcane belt found a variety of pesticides used in the sub-catchment, which are reported in this paper. Analysis of soil samples from seven fallow experimental field plots left uncultivated for various periods from 3 to 96 months after cultivation with pesticide application indicated persistence of high concentrations of pesticide residues in the soil, with estimated soil half-lives (in years) ranging from 0.72 to 57.75 for organochlorines and from 1.13 to 8.25 for herbicides. The mean water concentrations (in μg/L) of the pesticide residues in River Kuywa, which flows through the Nzoia Nucleus Estate sugarcane farms, ranged from 0.12 (lindane) to 1.36 (p,p′-DDT) for organochlorines and from 0.14 (atrazine) to 1.75 (diuron) for herbicides during the heavy rains period in August 2008 while the mean sediment concentrations (in μg/g) ranged from 0.28 (lindane) to 1.87 (endrin) for organochlorines and 0.39 (hexazinone) to 4.61 (alachlor) for herbicides. The mean concentrations of residues in water during the light rain period in December 2008 ranged from 0.17 (p,p′-DDT) to 0.71 (aldrin) for organochlorines and 0.01 (atrazine) to 1.74 (alachlor) for herbicides while the sediment concentrations ranged from 0.38 (p,p′-DDT) to 1.145 (aldrin) for organochlorines and 0.74 (atrazine) to 1.98 (alachlor) for herbicides. Although DDT, aldrin, dieldrin, and endrin were not reported in the survey, their presence in the fallow experimental field plot soils and in River Kuywa water and sediment could indicate previous application, lack of recorded data or illegal usage since 1997 when they were banned. Notably, the concentrations of alachlor, diuron, cypermethrin, and hexazinone in the water column were substantial indicating their extensive usage and residual persistence in the sub-catchment, with subsequent wash-off and leaching into River Kuywa. The concentration levels of some of the individual pesticides exceeded the EU limit requirements for drinking water and indicated potential risk to humans and cattle if the water is used without treatment.
The bioaccumulation and fate of a branched 14C-p-nonylphenol isomer in Lymnaea stagnalis L.
(2003) Lalah, Joseph O.; Behechti, Akbar; Severin, Gabriele F; Lenoir, Dieter; Günther, Klaus; Kettrup, Antonius; Schramm, Karl-Werner
A single branched isomer of p-nonylphenol, 4(3′,6′-dimethyl-3′-heptyl)-phenol, previously identified by gas chromatography-mass spectrometry as one of the major constituent isomers in p-nonylphenol (constituting approximately 10% of all its isomers), was synthesized and used in studies of its bioaccumulation and excretion in the hermophroditic pond snail Lymnaea stagnalis L. Branched isomers of nonylphenol are perceived to have more estrogenlike toxicity than the straight-chain isomers in addition to being more resistant to biodegradation in the environment. With an average static exposure concentration of 104 μg/L (range: 92–116 μg/L) in water at 19°C for 8 d, the uptake of the compound was found to be fairly rapid, reaching a peak concentration of 23,548 μg/kg of whole tissue wet weight after 5 d and a peak bioaccumulation factor (BAFw) of 242 (5,562, based on lipid weight) after 3 d. The uptake data fitted into a logarithmic expression C(t) = 5,231 ln(t) + 11,956, where C(t) is the amount of residues accumulated in whole tissue in micrograms per kilogram tissue wet weight after a period of time, t, and t is the period of exposure in days. By determination of the excretion of 14C-residues released in water and in feces, an average loss of 96% of the accumulated residues was achieved after 22 d of continuous exposure to clean water. By first-order kinetics analysis of the excretion data, an average half-life of excretion of 4.9 d was obtained. By high-performance liquid chromatography and gas-liquid chromatography-mass spectrometry, a catechol metabolite, 4(3′,6′-dimethyl-3′-heptyl)-catechol, was detected in tissue extracts (after hydrolysis with β-glucuronidase) and in feces, in addition to the parent isomer, suggesting that the isomer may have been metabolized by glucuronic acid conjugation and hydroxylation at the ortho position of its phenolic ring.
Biological cost of tolerance to heavy metals in the mosquito Anopheles gambiae
(2010) Mireji, PO; Keating, J; Hassanal, A; Mbogo, CM; Muturi, MN; Githure, JI; Beier, JC
The global rate of heavy metal pollution is rapidly increasing in various habitats. Anopheles malaria vector species (Diptera: Culicidae) appear to tolerate many aquatic habitats with metal pollutants, despite their normal proclivity for ‘clean’ water (i.e. low levels of organic matter). Investigations were conducted to establish whether there are biological costs for tolerance to heavy metals in Anopheles gambiae Giles sensu stricto and to assess the potential impact of heavy metal pollution on mosquito ecology. Anopheles gambiae s.s. were selected for cadmium, copper or lead tolerance through chronic exposure of immature stages to solutions of the metals for three successive generations. Biological costs were assessed in the fourth generation by horizontal life table analysis. Tolerance in larvae to cadmium (as cadmium chloride, CdCl2), copper [as copper II nitrate hydrate, Cu(NO3)2 2.5 H2O] and lead [as lead II nitrate, Pb(NO3)2], monitored by changes in LC50 concentrations of the metals, changed from 6.07 µg/L, 12.42 µg/L and 493.32 µg/L to 4.45 µg/L, 25.02 µg/L and 516.69 µg/L, respectively, after three generations of exposure. The metal-selected strains had a significantly lower magnitude of egg viability, larval and pupal survivorship, adult emergence, fecundity and net reproductive rate than the control strain. The population doubling times were significantly longer and the instantaneous birth rates lower in most metal-selected strains relative to the control strain. Our results suggest that although An. gambiae s.s. displays the potential to develop tolerance to heavy metals, particularly copper, this may occur at a significant biological cost, which can adversely affect its ecological fitness.
Blood Meal Analysis and Virus Detection in Blood-Fed Mosquitoes Collected During the 2006–2007 Rift Valley Fever Outbreak in Kenya
(2014) Lutomiah, Joel; Omond, David; Masiga, Daniel; Mutai, Collins; Mireji, Paul O; Ongus, Juliette; Linthicum, Ken J; Sang, Rosemary
Background: Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Blood-fed mosquitoes collected during the 2006–2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the blood meals. Materials and Methods: Blood meals from individual mosquito abdomens were screened for viruses using Vero cells and RT-PCR. DNA was also extracted and the cytochrome c oxidase 1 (CO1) and cytochrome b (cytb) genes amplified by PCR. Purified amplicons were sequenced and queried in GenBank and Barcode of Life Database (BOLD) to identify the putative blood meal sources. Results: The predominant species in Garissa were Aedes ochraceus, (n=561, 76%) and Ae. mcintoshi, (n=176, 24%), and Mansonia uniformis, (n=24, 72.7%) in Baringo. Ae. ochraceus fed on goats (37.6%), cattle (16.4%), donkeys (10.7%), sheep (5.9%), and humans (5.3%). Ae. mcintoshi fed on the same animals in almost equal proportions. RVFV was isolated from Ae. ochraceus that had fed on sheep (4), goats (3), human (1), cattle (1), and unidentified host (1), with infection and dissemination rates of 1.8% (10/561) and 50% (5/10), respectively, and 0.56% (1/176) and 100% (1/1) in Ae. mcintoshi. In Baringo, Ma. uniformis fed on sheep (38%), frogs (13%), duikers (8%), cattle (4%), goats (4%), and unidentified hosts (29%), with infection and dissemination rates of 25% (6/24) and 83.3% (5/6), respectively. Ndumu virus (NDUV) was also isolated from Ae. ochraceus with infection and dissemination rates of 2.3% (13/561) and 76.9% (10/13), and Ae. mcintoshi, 2.8% (5/176) and 80% (4/5), respectively. Ten of the infected Ae. ochraceus had fed on goats, sheep (1), and unidentified hosts (2), and Ae. mcintoshi on goats (3), camel (1), and donkey (1). Conclusion: This study has demonstrated that RVFV and NDUV were concurrently circulating during the outbreak, and sheep and goats were the main amplifiers of these viruses respectively.
Bounds for the Second Largest Eigenvalue of Real 3 × 3 Symmetric Matrices with Entries Symmetric about the Origin
(2012) Barini, Geoffrey; Kivunge, Benard; Akanga, Jotham
Let ASn[a,b] denote a set of all real nxn symmetric matrices with entries in the interval [a,b]. In this article, we present bounds for the second largest eigenvalue λ2(A) of a real symmetric matrix A, such that A∈AS3 [-b,b].
Can we exploit and adapt indigenous knowledge and ethno-botanicals for a healthy living in the face of emerging diseases like Ebola in Africa
(American Journal of Clinical and Experimental Medicine, 2015-02-14) Suki, K. K. Mwendwa
In this essay, we attempted to catalogue and describe African indigenous knowledge, in contributing to sustainable health development in Sub Saharan Africa. In the face of poverty and threats of diseases such as ebola.We also describe how biotechnology can enhance cultural mechanism for improved health care. A snap shot of certain cultural habits that promote disease dissemination that would have to be modified is described. This report is basically a descriptive essay and partly based on a survey and collection of indigenous practices in Cameroon, and some cultures across countries in SSA. Some of the traditional knowledge relevant to disease transmission and control may form basis for experimentation, validation, development and application of appropriate medical biotechnologies for cheap, low tech disease control strategies and healthy living through a number of ethnobotanicals medicines, such as Occimum basilicum popularly called holy basil and in Kom language known as afuaih toh by many ethnicities of the Tikar in Ghana, Uganda, Gabon, parts of Kenya and Tanzania, Equitorial Guinea, Ethiopia, and Madagascar, who believe that the aromatic smell it emits dispels not only evil spirits but certain diseases such as HIV, Ebola and disease vectors. Such indigenous knowledge and science, with simple skills and familiarity, applied as an innovative approach to hygiene, medical challenges and disease control. Understand the practices, and see how to introduce interventions (incremental interventions), with existing indigenous knowledge enhanced with present science and technology, which you see can be applied to resolving present and possible outbreaks like Ebola. Generally called Macepo, tribes in Bukuru in northern Nigeria often used it to preserve dead bodies in remote villages where neither hospital nor morgue exist for days pending burial. Could scientific attention validate the use of African indigenous knowledge in Ebola prevention or future emerging diseases so that Africans can carry out safe burials within the context of their culture without risk of disease spread? We noted the believe amongst most ethnic groups regarding the use of Occimum basilicum, and leaf powder of some indigenous plants as a preservative for corpse or crops and insect repellent.This could serve as excellent platforms for mitigation and control of outbreaks such as Ebola.
Carbofuran and its Toxic Metabolites Provide Forensic Evidence for Furadan Exposure in Vultures (Gyps africanus ) in Kenya
(2010) Otieno, Peter O; Lalah, Joseph O; Virani, Munir; Jondiko, Isaac O; Schramm, Karl-Werner
Forensic analysis of carbofuran residues in weathered tissue samples for evidence of Furadan exposure in vultures (Gps africanus) by HPLC gave concentration (mg/Kg dry tissue weight) ranges of bdl – 0.07 (carbofuran), bdl – 0.499 (3-ketocarbofuran) and 0.013–0.147 (3-hydroxycarbofuran) in beaks, bdl–0.65 (carbofuran), 0.024–0.190 (3-ketocarbofuran) and 0.017–0.098 (3-hydroxycarbofuran) in feet, 0.179–0.219 (3-ketocarbofuran) and 0.081–0.093 (3-hydroxycarbofuran) in crop content, 0.078–0.082 (3-ketocarbofuran) and 0.091–0.101 (3-hydroxycarbofuran) in muscle of a laced carcass and 0.006–0.014 (carbofuran), 0.590–1.010 (3-ketocarbofuran) and 0.095–0.135 (3-hydroxycarbofuran) in soil sampled from a poisoning site. These compounds were confirmed by GC-MS. The results showed that HPLC combined with GC-MS is suitable for forensic analysis of carbofuran residues in bird tissue samples and that forensic investigation should include its two toxic metabolites, 3-hydroxycarbofuran and 3-ketocarbofuran.
Carbofuran use and abuse in Kenya: residues in soils, plants, water courses and the African white-backed vultures (Gyps africanus ) found dead
(2011) Otieno, Peter O; Lalah, Joseph O; Virani, Munir; Jondiko, Isaac O; Schramm, Karl-Werner
The increasing number of incidences of alleged wildlife poisoning with Furadan in Kenya has sparked off a strong lobby fronted by wildlife conservationists against Furadan use in the country and prompted this study. The worst-case scenario was in 2004 in Athi River, where a massive number of 187 African white-backed vultures (Gyps africanus) and hyenas were found dead at a spot where poisoning was suspected to have occurred through a Furadan-laced camel carcass bait. This study was initiated by the Peregrine Fund—Africa Project, and the objective was to provide evidence for Furadan exposure, its misuse and involvement in vulture poisoning and potential impact on areas near two wildlife conservancies in two most affected districts. The study found evidence for ready availability of Furadan 5G in local veterinary retail shops and its illegal misuse by pastoralists and farmers against wildlife to protect their animals and crops. Analysis of soil, water and plants taken from the farms and water sources by high-perfomance liquid chromatography (HPLC) and gas liquid chromatography–mass spectrometry (GC–MS) found residues of carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran, indicating that Furadan was used extensively in farming causing residual environmental distribution and contamination and posing risks to small birds and mammals. Forensic analysis of residues in beaks, feet and crop content of the dead vultures as well as in a laced camel carcass bait and soil samples from one site of poisoning also showed carbofuran and its two metabolites supporting allegations of Furadan involvement in wildlife poisoning and high-mortality cases of African white-backed vultures (Gyps africanus) in Kenya.
Changes in genotypes of Plasmodium falciparum human malaria parasite following withdrawal of chloroquine in Tiwi, Kenya
(Elsevier, 2012) Mang’era, Clarence M.; Mbai, Fiona N; Omedo, Irene A; Mireji, Paul O; Omar, Sabah A
Chloroquine (CQ) drug was withdrawn in 1998 as a first-line treatment of uncomplicated malaria in Kenya. This was in response to resistance to the drug in Plasmodium falciparum malaria parasite. Investigations were conducted to determine prevalence of CQ resistance genotypes in the parasites in Tiwi, a malaria endemic town in Kenya, before and about a decade after the withdrawal of the drug. Blood samples were collected and spotted on filter papers in 1999 and 2008 from 75 and 77 out-patients respectively with uncomplicated malaria. The sampling was conducted using finger pricking technique. DNA was extracted from individual spots in the papers and screened for the presence of P. falciparum chloroquine resistance transporter (Pfcrt) and multi drug resistance (Pfmdr-1) markers using nested PCR. Nature of mutations (haplotypes) in the Pfcrt and Pfmdr-1 markers in the samples were confirmed using dot blot hybridization technique. Changes in pattern of CQ resistance in the parasite samples in 1999 and 2008 were assessed by Chi Square test. There was a significant (P < 0.05) reduction in CQ resistant genotypes of the parasite between 1999 and 2008. Pfmdr and Pfcrt CQ resistant genotypes in 2008 reduced to 54.10 and 63.64% respectively, from 75.39 and 88.0% respectively in 1999. This reduction was accompanied by emergence of Pfcrt specific CQ sensitive (IEK) and intermediate/partially CQ resistant (MET) haplotypes. Results suggest significant reversal of the phenotype of the parasite from chloroquine resistant to wild/sensitive type. The novel haplotypes indicates transitional phase of the parasite to the wild type. Current prevalence of chloroquine resistant genotype is definitely above the threshold for efficacious re-introduction of chloroquine for treatment of malaria in Tiwi.
Characterisation of Murine Endometrial Epithelium in Vitro: Effects of Epidermal Growth Factor.
(1997) Mbai, Fiona N

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