School of Biological and Physical Sciences

Assessment of the effects of water quality parameters on zooplankton distribution, diversity, and abundance in water pans of semi-arid Narok, Kenya

Wed, 01 Jan 2025 00:00:00 GMT

Assessment of the effects of water quality parameters on zooplankton distribution, diversity, and abundance in water pans of semi-arid Narok, Kenya ACHIENG, Dorine Were Freshwater pans in Kenya’s semi-arid regions play an important role in supporting domestic use, irrigation, livestock, and aquatic biodiversity. However, they are increasingly threatened by climate variations, eutrophication, sedimentation, and overexploitation, all of which affect water quality and biological productivity. Understanding the interactions between water quality and zooplankton population is essential for maintaining the ecological integrity of these systems. This study therefore aimed to (i) assess variations in physico-chemical parameters, (ii) determine variations in zooplankton distribution, diversity, and abundance, and (iii) evaluate the influence of water quality parameters on zooplankton diversity and abundance in selected water pans of Narok County, Kenya. Sampling was conducted twice monthly between February and July 2023 across 20 water pans. In situ measurements were taken for temperature, dissolved oxygen (DO), pH, and electrical conductivity (EC), while nutrients (total nitrogen and total phosphorus) and chlorophyll-a were analyzed using standard laboratory methods. Zooplankton were identified and enumerated microscopically, and diversity indices were computed. Results showed that temperature ranged from 16.65–26.20 °C, DO from 0.40–9.55 mg/L, pH from 6.70–9.30, and EC from 79.83–761.85 µS/cm. Chlorophyll-a concentrations varied from 19.08–176.61 µg/L, total nitrogen from 393.00–2609.43 µg/L, and total phosphorus from 295.43–1331.14 µg/L. Zooplankton communities were dominated by Rotifera (48.9%), followed by Copepoda (25.8%), Cladocera (19.9%), and Ostracoda (5%). Diversity increased from February to June/July, with Shannon-Wiener Index rising from 1.76 to 1.96 and taxa richness from 14.21 ± 0.79 to 16.43 ± 0.67 (p = 0.043). Weak correlations between zooplankton abundance and most water quality parameters indicated that multiple interacting factors influence community composition. The study concluded that Narok water pans support diverse zooplankton under varying environmental conditions. Strengthening riparian vegetation, managing nutrient inflows, and regulating water abstraction are recommended to sustain ecosystem health and productivity. Master's Thesis

Effectiveness of permanet® dual on malaria vector control in a Pyrethroid resistant population of mosquitoes in western Kenya

Tue, 11 Nov 2025 00:00:00 GMT

Effectiveness of permanet® dual on malaria vector control in a Pyrethroid resistant population of mosquitoes in western Kenya OGUTU, Nashon Ang’ienda Malaria affected 263 million people and resulted to 597000 deaths globally. In Kenya 5.5 million malaria cases were reported in 2023. Malaria cases and deaths globally have decreased through long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS). However, intensive use of these strategies has led to a rise in resistance, which necessitated development and trials of new generation LLINs (nLLINs). New generation LLINs are products impregnated with a pyrethroid and another insecticide to enhance their efficacy against pyrethroid resistant malaria transmitting mosquitoes. However, there are gaps in knowledge regarding effectiveness of nLLINs on vectors resistant to pyrethroids. Specific objectives of the work were to evaluate phenotypic resistance on malaria vectors between nLLINs and pyrethroid only nets; to determine the difference in blood feeding inhibition (BFI) of malaria vectors between nLLINs and untreated nets, and to determine the difference in mortality of malaria vectors between nLLINs and untreated nets in western Kenya. This was an experimental huts study with seven arms, where each study hut was weekly allocated different treatments of the nLLINs, namely permanet 3.0 (PN 3.0), permanet dual (PD), interceptor G2 (IG2), as unwashed and after 20X washes, together with an untreated Polyester net (UN X0). The huts were randomly allocated sleepers daily. Mosquito samples were collected from the huts every morning from 6:30 AM to 8:30 AM, to aid in efficacy assessment of the study treatments against wild malaria vectors. Data analysis for phenotypic resistance was calculated as mortality proportions and analyzed using Fisher’s exact test. Data on blood feeding inhibition and mortality were analyzed utilizing ANOVA and Tukey (HSD) test. The study detected phenotypic resistance of 66.7% with An. gambiae and 88.9% with An. funestus, against pyrethroids as well as significant association between phenotypic resistance and net types among mosquito species; An. gambiae X2 =7.1875, p – value 0.03; An. funestus X2 = 11.875, p = 0.003. ANOVA test for BFI and mortality produced p-values of 0.000 and 0.001<0.05 respectively. Significant differences in blood feeding inhibition were noted between UN X0 vs PD 20X , PN 3.0 0X, PN 3.0 20X, IG2 20X, all with adjusted p. values of less than 0.05. PN 3.0 0X vs IG2 0X and PD 0X (adjusted p. values <0.05) and PN 3.0 20X vs IG2 0X and PD 0X (all with p values <0.05). On mortality, UN 0X vs IG2 20X, PD 0X and PD 20X, with adjusted p-values of 0.008, 0.005 and 0.002, respectively, which were statistically significant. Overall, the study confirmed existence of significantly different phenotypic resistance between nLLINs relative to the conventional interventions, thus affirming the importance of nLLINs as probable substitutes in the fight against pyrethroid resistance. PN3.0 was found to be the better product based on its significantly better BFI performance. PD proved to be the best product on mosquito mortality and was the promising intervention for future consideration in that regard. Altogether, PD was found to be effective against the An. funestus mosquitoes, due to its outstanding mortality results. There is need for continuous monitoring of insecticide resistance situation in regions facing pyrethroid resistance to keep abreast and properly manage the resistance from an informed opinion. Altogether, use of nLLINs is an effective intervention against insecticide resistance. Master's Thesis

Effect of periphyton technology on the growth performance and fecundity of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) cultured in earthen ponds

Sat, 01 Jan 2022 00:00:00 GMT

Effect of periphyton technology on the growth performance and fecundity of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) cultured in earthen ponds MAVINDU, Muthoka Aquaculture plays a big role in eliminating poverty and malnutrition. However, the current pond-based systems rely on the supply of large amounts of low-quality commercial feeds that limit aquaculture productivity and have the potential to cause environmental problems such as eutrophication in the receiving waters. Poor brood stock productivity remains a major constraint in aquaculture growth. Early sexual maturation of O.niloticus before it attains market size results to stunted growth affecting its productivity. The present study was therefore guided by the following specific objectives: i) To determine the effect of periphyton technology (PPT) on the growth performance indicators of O. niloticus reared in earthen ponds ii) To determine the effect of PPT on the fecundity of O. niloticusiii) To determine the effect of PPT on plankton diversity and abundance iv) To determine the effect of PPT on pond water quality parameters. The research was done at Kenya Marine and Fisheries Research Institute (KMFRI), Sang’oro.Six earthen ponds used for the study were limedat a rate of 4 g.m-2 and filled with water one week after liming. The ponds were fertilized using chicken manure. Two treatments, i.e., PPT-and control-ponds, were evaluated in the study and triplicated. The PPT ponds were fitted with 2-m long eucalyptus poles of 5 cm diameter at 50 cm interval with the inclusion of molasses as carbon source. The control ponds were not treated. Tilapia fish (mean weight, 12.35±0.15g) were stocked in all ponds at a density of 3fish/m2, and fed on a commercial diet with 20 % crude protein (CP) twice daily at 3 % body weight. 30 fish were sampled weekly from each pond for growth, and 10 fish were sampled bi-weekly for the determination of fecundity. Water samples were collected from the ponds to determine plankton abundance and diversity. Selected physicochemical water parameters were monitored in situ weekly using multi-parameter meter. Total ammonia nitrogen (TAN) was measured in a laboratory using standard procedures. R software version 3.2.1 was used to conduct statistical analysis. The effects of PPT on growth performance, fecundity of O. niloticus, water quality parameters, plankton diversity and abundance were analyzed using independent t-test. The PPT-ponds registered significantly higher mean weight (150.69 ± 0.99 g), SGR (2.75 ± 0.01), and lower FCR (1.29 ± 0.01),than the control ponds: Mean weight (99.23 ± 0.96 g), SGR (2.29 ± 0.00), and FCR (1.58 ± 0.01).There was significantly higher fecundity in the PPT-ponds (2.28 ± 0.09 g) than control (1.74 ± 0.06 g.fish-1) with prolific spawning behavior starting earlier in the fourth week in control pond (fish mean weight, 29.19 ± 0.26) but delayed to the eighth week in the PPT-ponds with fish having a mean weight of 81.37 ± 0.51. PPT-ponds had a higher phytoplankton and zooplankton diversity index of 3.19 and 3.42, respectively, compared to 2.57 and 2.34, respectively, in control-ponds. There was a significantly higher zooplankton mean abundance in the PPT-ponds (2771.83 ± 313.11)than in control (262.67 ± 16.78). The control-ponds recorded significantly higher concentrations of nitrite (0.07 ± 0.01 mg.L-1), ammonia (0.21 ± 0.03 mg.L-1) and ammonium (0.20 ± 0.04 mg.L-1)compared to PPT-ponds: nitrite (0.02 ± 0.01 mg.L-1), ammonia (0.06 ± 0.01 mg.L-1), and ammonium(0.02 ± 0.01 mg.L-1). This study demonstrated that PPT is a quality natural fish feed that can be used with supplemental feed to replace the costly commercial fish feeds. PPT also has a high potential of improving the water quality of the culture system, thereby providing the ideal conditions for maximum growth of fish. The present study recommends the adoption of PPT in replacing the costly commercial fish feeds used in tilapia culture. Further studies are recommended to explore other substrates for installing PPT in ponds. Masters Thesis

Assessment of the Levels of Micronutrients in Black Tea from Different Regions Of East Africa and Changes In their Levels Due to Agronomic Practices

Sat, 01 Jan 2011 00:00:00 GMT

Assessment of the Levels of Micronutrients in Black Tea from Different Regions Of East Africa and Changes In their Levels Due to Agronomic Practices OMWOYO, Wesley Nyaigoti Inadequate supply of micronutrients causes human h~ealth complications and is a worldwide problem now referred to as hidden hunger. Beverages from Camellia sinensis are claimed to be the most widely consumed fluids after water. However it is not known if they contain adequate ,Ie.vels of micronutrients to alleviate hidden hunger problems. The levels of micronutrients in East African teas are unknown and factors controlling their absorption from the soil remain obscure. The objective of this study was to assess levels of micronutrients in East African teas, • 0::..local market teas and their infusions, establish if their levels vary with nitrogen fertilizer rates and plucking intervals and determine if there are variations in micronutrient level in the black tea of tea clones planted in various geographic locations. The micronutrients Mn, Fe, Zn, Cu and Se levels from 42 factories in East Africa and effects of grading on the micronutrients levels in four tea grades were assessed in 'acomplete1y randomized design and two factor completely randomized design respectively. The effects of nitrogenous fertilizer and plucking intervals on micronutrient content of clone 6/8 planted in' Timbilil, Sotik Highlands and Changoi were assessed in a three factor randomized complete block design. The levels of these minerals were also assessed in black tea of different clones planted in Kangaita, Kipkebe and Timbilil in a factorial two design randomized in a complete block design replicated three times under similar agronomic practices. The black tea samples were ashed, acid digested and extracted for analysis using the AAS. Mn levels were highest while Se levels were lowest. Mean levels of other micronutrients were in the order Fe>Zn>Cu. Large particle size grades had more (p:SO.05) micronutrients. Teas from the local market had higher levels of micronutrients than exported teas and the levels varied significantly (p:S0.05) among the grades. About 41% and 82% Mn and Cu was extracted in hot water infusion respectively while Fe extracted was only 17%. A cup of tea from 2.0g tea can contribute 57%, 1.03%, 0.65%, 2.0% and 2.85% of Mn, Fe, Zn, Cu and Se respectively of daily minimum requirement. Thus consumption of more than two cups of tea per day can supply daily requirements of Mn. However adequate daily supply of other micronutrients must be supplied by other foods. All the micronutrients significantly (p:S0.05) varied with location of production. Mn and Se levels were not significantly (p:S0.05) affected by increasing rates of nitrogenous fertilizer, Fe and Zn significantly (p:S0.05) increased while Cu levels significantly (p:S0.05) reduced. Plucking intervals did not significantly (p:SO.05) affect the micronutrient content of the resultant black teas. Different clones showed varied (p:SO.OS) micronutrient content when planted in a single location under similar agronomic practices and did not follow a similar pattern when the clones were planted in different locations. To increase micronutrient levels in tea, it is necessary to optimize nitrogen fertilizer rates and use suitable clones for different geographic locations.

Comparative Annotation and Analysis of Protein-Coding DNA Sequences (CDS) Of Theileria Parva Marikebuni and Theileria Parva Muguga Genomes

Sat, 01 Jan 2011 00:00:00 GMT

Comparative Annotation and Analysis of Protein-Coding DNA Sequences (CDS) Of Theileria Parva Marikebuni and Theileria Parva Muguga Genomes OBIERO, George Fredrick Opondo Theileriaparva Muguga genome was the first to be sequenced and published in this genus of great economic, veterinary and biological importance to livestock industry in East and Central Africa. The aim was to aid in identification of schizont antigens for vaccine development and to enhance comparative genomics with other related apicomplexas. To add to the repertoire of resource base, T parva Marikebuni was recently sequenced because of its high genotypic diversity given that its infection cannot be-cross-protected by the Muguga cocktail vaccine. Reported here is the annotation and curation of protein-codingDNA sequences (CDS) of the partial genome of T. parva Marikebuni against T. parva Muguga via Artemis ComparisonTool (ACT). The genome was analyzed for both strain-specific micro- and macrosatellite markers (also called variable number tandem repeats, VNTRs) and codon usage bias of coding open reading frames (ORPs) containing the VNTR markers. The results reported here showedthat T parva Marikebuni has a compact but protracted nuclear genome, encoding over 3900 CDS. The majority of these CDS are predicted as multi-exonic, but with lower count number relative to those observed in T parva Muguga genome. The genome is ATrich with about 32.64% GC content and shares a perfectsynteny with the template genome in terms of gene structure and nucleotide composition. The CDS were assigned unique feature identifiers including putative functions from database gene ontologies (GO). This study was able to characterize and locate the VNTRs within both genomes. Most VNTRs were found to be located in the non-coding regions of the genomes but peculiarly, seven of them were located in exonic ORFs. The codon usages in these genomes are biased towards AT-rich codons as would positively be expected of AT-rich genomes. Statistical analysis at 0.05 confidence showed that there was no significant difference in the codon usage both within and between the Theileria genomes. These results will be crucial in building of T parva database and make mining of the micro- and macro-satellites for any future comparative studies achievable. The findings will further enhance the search and prediction 'of the many T parva genes with unknown functions. In addition, the present study will aid in definition of strain-specific markers if the whole T parva Marikebuni genome can be completely sequenced.

Coordination Chemistry and Liquid-Liquid Extracnon of Zinc(Ii), Cadmium(Ii) and Lead(Ii) Cations With .. (Pyrazol-I-Ylmethyl)Pyridine Ligands

Sat, 01 Jan 2011 00:00:00 GMT

Coordination Chemistry and Liquid-Liquid Extracnon of Zinc(Ii), Cadmium(Ii) and Lead(Ii) Cations With .. (Pyrazol-I-Ylmethyl)Pyridine Ligands NYAMATO, George Simba Amongstthe countless man-made contaminants that infiltrate our water sources are heavy metals, usually as by-products of industrial processes. Many metals, particularly heavy metals are toxic. Metal contamination (e.g, Hg, Pb, Cd, etc.) can\be addressed by using filters/sorbents (e.g. gamma alumina), and flocculation/precipitation,1mt these methods are non-specificand best suited to contaminants at high concentrations. Chelating extraction is a potential technology of remediation for heavy metals-contaminated water and as such considerable attention has been devoted to the development of chelating agents for liquidliquid extraction of metal ions. The ligands 2,6-bis(pyrazol-I-ylmethyl)pyridine (LI), 2,6bis(3,5-dimethylpyrazol-I-ylmethyl)pyridine (L2), 2,6-bis(3,5-ditertbutylpyrazol-lylmethyl)pyridine (1..3), 2-(pyrazoI-I-ylmethyl)pyridine (IA), 2-(3;5-dimethylpyrazol-lylmethyl)pyridine (L5) and 2-(3,5-ditertbutylpyrazol-I-ylmethyl)pyridine (L6) were prepared and their coordination chemistry with zinc and cadmium metal ions investigated prior to their applications as chelating agents to remove heavy metals from water. Ligands L2, L5 and L6 reacted with either Zn(N03~, ZnCh, Cd(N03)2 or CdCh to form monometallic complexes [Zn(NOl~{L5)] (CI), [Zn(NOl~(L6)] (C2), [ZnCb(LS)] (C3), [Cd(N03)2(L5)] (C4), [Cd(NOlh(L6)] (CS), [CdCh(L5)] (C6), [Zn(N03)2(L2)] (C7), [ZnCb(L2)] (C8), [Cd(N03h{L2)] (C9), (CdCb{L2)] (CIO). All the new compounds prepared were characterized by IH NM:R.and elemental analyses. Single crystal X-ray crystallography of complexes CI, Cl, C4, CS, C7 and C9 has been used to confirm the solid state structure of the complexes. L5 and L6 adopts bidentate coordination mode through the pyridine nitrogen and one pyrazolyl nitrogen atom as confrrmed by single crystal X-ray crystallography of complexes Ct, 0, C4 and CS. The tridentate coordination ofL2 has also been established by the solid state structures ofC7 and C9. The abilities of 2,6-bis(pyrazol-I-ylmethyl)pyridine (Lt), 2,6-bis(3,5-dimethylpyrazol-I-ylmethyl)pyridine (L2), 2,6-bis(3,5-ditertbutylpyrazol-I-ylmethyl)pyridine (LJ), 2-(pyrazol-lylmethyl)pyridine (U), and 2-(3,5-dimethylpyrazol-I-ylmethyl)pyridine (LS) to extract heavy metal ions, (lead(ll), cadmium(Il) and zinc(Il) were examined by liquid-liquid extraction experiments using dichloromethane-water biphasic system Extraction efficiency was found to be dependent on the type of metal cations. All the ligands showed greater extraction efficiency for zinc (88-99%) and lowest extraction for cadmium (19-31%). The ligand architecture as well as experimental conditions such as metal:ligand ratio, time of reaction influenced the extraction efficiency of the ligands. Theoretical studies using Density Functional Theory by Gassian03 have been used to explain the observed experimental trends.The theoretical results were consistent with the experimental results , with zinc(ll) giving the highest negative enthalpy followed by le~(ll) and cadmium(II) giving the lowest.

Assessment of the Floral Diversity along Disturbance Gradient in Kaya Muhaka Forest, Msambweni District

Sat, 01 Jan 2011 00:00:00 GMT

Assessment of the Floral Diversity along Disturbance Gradient in Kaya Muhaka Forest, Msambweni District MAKOKHA, Derek Wambulwa Kaya Muhaka Forest in the Kenyan Coast is one of the remianng lowland forest patches belonging to Zanzibar-Inhambane vegetation mosaic of Eastern Africa, which are rich in \ endemic and threatened flora and fauna. Although gazetted and protected as a national monument, the forest biodiversity is still endangered. This research attempted to establish the flora diversity along disturbance gradient ranging from the forest core to the agro-ecosytems of the forest. The belt transect method was used where quadrants of 20m x 20m placed at intervals of every 250m were systematically selected along two parallel transects of 3km long each and all the plant species recorded. An additional nine plots of similar size and placement were surveyed on three parallel transects of 1km each established from the edge of the forest to the forest core. The flora diversity was calculated by use of the Shannon Wiener Index of diversity. The Importance Value Index, forest strcture, the species area curve and dominance were determined. Other ecological attributes established included species composition, and canopy cover. The distribution and conservation status of endangered species was studied by means of random walks and georeferencing the target species using Global Positioning System Forest disturbance was also recorded by use of indictaors such as presence of paths, tree stamps and evidence of firewood collection. Scorodophloeus fisheri (Taub) J. Lion was the most important species in the forest and Cocos .nucifera L. was the most important in the farmland. A total of 492 species in 92 families were recorded. The forest was found to be heavily disturbed with numerous paths crossing it. The threatened speices are not protected and they risk being logged. There was a high diversity of plant species in the Kaya Muhaka forest and agro-ecosystems. The forest is homogenous with most of the species being indigenous and endemic. The protection of the forest should be improved. Further research should be done on the conservation, presence and mapping of the endangered species in Kaya Muhaka forest.

Occurrence and Antimicrobial Profiles of Salmonella Sp in Fish (Oreochromis Niloticus) and Selected Fish-Ponds in Western Kenya

Sat, 01 Jan 2011 00:00:00 GMT

Occurrence and Antimicrobial Profiles of Salmonella Sp in Fish (Oreochromis Niloticus) and Selected Fish-Ponds in Western Kenya WERE, Jeremiah Wafula Salmonella, a gram-negative facultative rod shaped bacterium: '--'in the family Enterebacteriaceae, is found in the intestinal tracts of humans and animals. Salmonella causes salmonellosis, which manifests as two diseases in humans: enteric fever (typhoid) and acute gastroenteritis. Salmonellae are disseminated to the external environment, such as water, soil and plants, through human or animal excretion. Fish farming has become an important practice in Western Kenya where two species, namely Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) are reared for subsistence and for commercial sales. It has however been established that fish can serve as carriers or infectious source of pathogens such as Mycobacteria, Streptococcus iniae, Vibrio spp., aeromonads and Salmonella spp. Currently, there is a rise in the incidence of antimicrobial resistant bacteria including Salmonella. This has become of critical concern in the world, with about 1.3 billion cases and 3 million deaths reported annually due to multidrug resistant (MDR) Salmonella. In Kenya, the prevalence ofMDR Salmonella has been rising steadily since it was first reported between 1997 and 1999. The aim of this study was to determine the incidence of Salmonella and analyze their antimicrobial profile in farmed fish and fish ponds in the community around Maseno University in Maseno division in Western Kenya. Nineteen Salmonella isolates were obtained from the flesh and intestines of fish (n=55) and water collected from eleven fish farms. Two isolates were Salmonella enterica serovar Typhi and 4 were Salmonella enterica serovar Typhimurium due to the presence of malate dehydrogenase (mdh) gene (261bp). Ninety five percent of the Salmonella isolates were resistant to Ampicillin, 89% to kanamycin, 84% to chloramphenicaJ, 63% to streptomycin, 31% to tetracycline, ]6% to gentamicin, and 11% to cotrimoxazole. BlaTFM, a gene that confers resistance to p-Iactams and cephalosporins was amplified in 61% Salmonella isolates. The incidence of Salmonella spp was 45% in the fish ponds and 15.7%'fish. These findings indicate that fish from fish farms around Maseno University contain MDR Salmonella which may infect humans. It is therefore important that the farmers improve the hygiene of their fish farms and that consumers prepare their fish properly to cut the cycle of infection from man to fish and back to man.

Toxicity and Mortality of Synergized Crude Essential Oil Extracts from Tagetes Minuta (L.) on Periplaneta Americana (Blattidae)

Sat, 01 Jan 2011 00:00:00 GMT

Toxicity and Mortality of Synergized Crude Essential Oil Extracts from Tagetes Minuta (L.) on Periplaneta Americana (Blattidae) OTENG'O, Antony Otinga Cockroaches are insects that belong to the order Blattodea, suborder Blattaria and family Blattidae. The species that is most common and wide spread in the world is Periplaneta americana(L.). They are increasing in number due to their resistance to synthetic insecticides that are in most cases used in their control. This has made them a public health problem due to their close association with human wastes and they are mechanical transmitters of human disease causing pathogens. Therefore there is need of coming up with an alternative insecticide. Although studies have shown that the Tagetes minuta(L.) has insecticidal properties, this property has not been tested on cockroaches. T minuta's insecticidal compounds have never been synergized with oil components of Sesamum indicum(L). In the present study, synergized crude essential oil extracts from T minuta were tested as a potential fumigant and contact toxicant on P. americana. The study took place in Maseno Division where 35 households were interviewed using questionnaires and P. american a collected from their premise. The crude essential oil extracts were obtained from floral and folia parts of the plant by percolating with methanol and rotorvaping, then synergized with oil components (methanol extract) from S. indicum seeds. The mixture of the two oils was tested for toxicity on the P. americana in the laboratory using bio-assay method; where cockroaches were exposed to insecticide. The tersi, tracheal and nervous systems of the P. american a were histologically examined to establish how the affected cells and tissues differ from the unaffected ones. Biopac MP35 unit was used to discern the physiological effect of the crude essential oil extracts from T minuta by doing extracellular multiunit record on the P. americana. Data from questionnaires was converted into frequency counts and percentages using SAS statistical analysis software. Susceptibility of P. americana to T minuta's crude essential oil extracts was analyzed as a four factorial experiment. ANOVA and Duncan's Multiple Range test were used to test for significance of the experiments at P::;0.05, LCso of T .minuta's synergized and non-synergized extracts were determined using probit analysis method. From the questionnaires, 83% of the households admitted to cockroach menace; 54% use insecticides to control them and 91% said that not all cockroaches die after treatment. LCso of synergized extract was 6.31 g/L while that for non-synergized extract was 8.91 g/L. Non-synergized extract had a mortality of 48 (n=60) while synergized extract had mortality of 60 (n=60). 120 g/L of both synergized and non-synergized extract had knockdowns and kills made within 20 and 25 minutes respectively. Oil .components of S. indicum synergized T minuta's crude essential oil extracts thus reduced knockdown and kill times and increased the cockroaches' mortality. T minuta's insecticidal compounds did not cause anatomical changes on the tersi, tracheal and nervous tissue; it worked physiologically via impairing the function of Na+ ion channels of the neurons thus killing P. americana. In conclusion, cockroaches are a menace. to households of Maseno and they are susceptible to synergized and non-synergized extracts from T minuta.

Plasmodium Falciparum Reticulocyte Parasitation in Children and adults With Uncomplicated Malaria: Association With Clinical, Parasitological and Haematological Outcomes in Western Kenya

Sat, 01 Jan 2011 00:00:00 GMT

Plasmodium Falciparum Reticulocyte Parasitation in Children and adults With Uncomplicated Malaria: Association With Clinical, Parasitological and Haematological Outcomes in Western Kenya OKOTH, Patrick Reticulocytosis is an imp~rtant previously unappreciated surrogate marker of recent Plasmodium Jalciparum reticulocyte parasitation. Evidence from studies in murine rand primate models show increased prevalence nf Plasmodium Jalciparum parasitisation of reticulocytes. The increase in reticulocyte infection has been attributed to compensatory reticulocytosis and increased parasite densities However, the prevalence of P. falciparum parasitisation of reticulocytes in human p~Pl-lations in holoendemic areas of malaria is unknown. Therefore, the current study examier ~the prevalence of P.falciparum parasitation ofreticulocytes and its association with clinical parasitological and haematological outcomes in children (n=164) and adults (n=41) with <::\~t.eP. falciparum malaria and healthy malaria negative controls (children, n=132 and adultr, l=60) from a holoendemic area of malaria of western Kenya. Malaria diagnosis and species identification was performed using Giemsa stained thick and thin blood smears while reticrocyte parasitation was determined using New Methylene Blue- Giemsa counter-stained thini Led films. Results of this study showed that children with malaria presented with increased lumbers of infected reticulocytes compared to adults with malaria (p=0.006; Mann- Whitne: ~j test). In addition, children with malaria presented with higher reticulocyte counts .x» apared to those without malaria (p<0.0001; Mann-Whitney U test). Dichotomization of': h ldren and adults with malaria into presence or absence of infected reticulocytes revealec 1 iat presence of infected reticulocytes was associated with higher parasite densities (p