Faculty of Science & Technology (FST): Recent submissions
Now showing items 2721-2740 of 4283
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Growth rates of ferromanganese encrustations on rocks from the Romanche Fracture Zone, Equatorial Atlantic
(Department of Geology, University of Nairobi, 1992)Based on radiochemical techniques, ferromanganese oxide crusts from the Romanche Fracture Zone (RFZ) have accretion rates ranging between 1.4 and 2.8 mm/10 years. In comparison with other ferromanganese deposits, the ... -
Analysis of trophic relationships in two shallow equatorial lakes Lake Naivasha (Kenya) and Lake Ihema (Rwanda) using a multispecifies trophic model
(Department of Zoology, University of Nairobi, 1996)A multispecifies trophic model called ECOPATH II, which can be used to describe the trophic relationships in aquatic ecosystems on a quantitative basis, is briefly presented. When properly used, it can help to explain the ... -
Geological evolution of coastal Kenya as inferred from sedimentary sequences and marines terraces
(Department of Geology, University of Nairobi, 1996)Based on extensive field and literature surveys together with radiometric dating evidence, the coastal geology of Kenya consists of the Karoo (Upper Carboniferous-Lower Jurassic) to Recent sedimentary sequences with minor ... -
The relationship between nutrients and trophic-level biomass in turbid tropical ponds
(Department of Zoology, University of Nairobi, Nairobi, Kenya, 1998)The total phosphorus–algal biomass relationship from a set of turbid tropical ponds in Kenya was compared with predictions derived from surveys of temperate and subtropical lakes. Despite high concentrations of total ... -
Coastal Tidally-driven Circulation and the Role of Water Exchange in the Linkage Between Tropical Coastal Ecosystems
(College of Biological Sciences, University of Nairobi, 1997)Water circulation and exchange processes in a shallow, semi-enclosed tropical bay were studied in southern Kenya (Gazi Bay) through measurements of tidal elevations, salinity, temperature, dissolved oxygen and current ... -
Beach erosion: case studies on the East African coast
(1992-10)Marine erosion of late Holocene beach deposits is a common problem 011 the equatorial coasts of the western Indian Ocean, damaging or threatening tourism-related investment and communication infrastructure. The problem ... -
The Effect Of Immunizing Swiss White Mice With Snail Soluble Proteins And Challenging Them With Schistosoma Mansoni
(ISPUBSchool of Biological Sciences, University of Nairobi, 2012)Schistosomiasis infects approximately 700 million people in 74 endemic countries. It causes high morbidity. Although the drug of choice, Praziquantel is effective against Schistosoma mansoni, there is a problem of rapid ... -
African greenhouse gas emission inventories and mitigation options: forestry, land use change, and agriculture
(Department of Geology, University of Nairobi, 1995-05-29) -
Antimicrobial Abietane Diterpenoids from Clerodendrum eriophyllum
(Department of Chemistry, University of Nairobi, 2010)Clerodendrum eriophyllum Gürke (Verbenaceae) is a shrub or small tree distributed in the dry bushlands of Eastern Kenya. The plant has no record of previous phytochemical analysis. A bioassay guided isolation of the methanol ... -
Phytochemical Evaluation of So me Kenyan Medicinal Plants
(Department of Chemistry, University of Nairobi, 2010)11 th NAPRECA Symposium Book of Proceedings, Antananarivo, Madagascar Pages 9-19 Midiwo et al. 9 Phytochemical Evaluation of So me Kenyan Medicinal Plants J. Ogweno Midiwo, A. Yenesew, B.F. Juma Kerubo L Omosa, ... -
Phytochemical, Antiparasitic and Antimicrobial Investigations of Terminalia brownii
(Department of Chemistry, University of Nairobi, 2013)Terminalia brownii is an African medicinal plant used to treat parasitic and microbial infections [1]. Chromatographic separations on the stem bark extract aimed at identifying the active components led to isolation of a ... -
Antiparasitic and antimicrobial isoflavanquinones from Abrus schimperi.
(2011-11)The EtOH extract of Abrus schimperi (Fabaceae), collected in Kenya, demonstrated significant activity against Leishmania donovani promastigotes with IC50 value of 3.6 microg/mL. Bioassay-guided fractionation of CHCl3 ... -
Antiparasitic and anticancer carvotacetone derivatives from Sphaeranthus bullatus
(Department of Chemistry, University of NairobI, 2012-09)The 1:1 MeOH/CH2Cl2 extract of aerial parts of Sphaeranthus bullatus, an annual herb native to tropical East Africa, showed activity against chloroquine sensitive D6 (IC50 9.7µg/ml) and chloroquine resistant W2 (IC50 ... -
Convergence of Padé Kernel Approximants to the Delayed Dirac Function
(University of Nairobi.Department of Mathematics, 1980)We derive from the solutions of Kummer's equation an expression for the exponential function, which when restricted to integer parameters gives the [M, N] Padé approximation and its error. Laplace inversion, using Bromwich's ... -
Three ent-trachylobane diterpenes from the leaf exudates of Psiadia punctulata
(ElsevierDepartment of Chemistry, University of Nairobi, 2006-07)Three ent-trachylobane diterpenes have been isolated from the leaf exudates of Psiadia punctulata and characterised as 6α,17,19-ent-trachylobantriol; 2α,18,19-ent-trachylobantriol; and 2β,6α,18,19-ent-trachylobantetraol. ... -
Toxicity and growth-inhibitory activity of Polygonum senegalense (Meissn.) surface exudate against Aedes aegypti larvae
(Department of Chemistry, and University of NairobiDepartment of Zoology, University of Nairobi, 1998)Laboratory studies were conducted to assess the toxicity and growth-inhibitory activity against Aedes aegypti larvae, of the crude acetone extracts of Polygonum senegalense (Meissn.) leaves, its flavonoid component ... -
On the Accuracy of Quadrature Laplace Transform Inversion and the Solution of State Space Equations
(University of Nairobi.Department of Mathematics, 1978)A quadrature formula is shown to be an approximation of the power-series method of inverting Laplace transforms. This together with the properties of the constants derived from a power-series expansion of the Padé approximation ... -
An Error Analysis and Convergence of a Quadrature Formula to Invert Laplace Transforms
(University of Nairobi.Department of Mathematics, University of Nairobi, 1977)The use of an expression for the exponential function exp(st) in Bromwich's integral, which incorporates a Padé approximation, yields a well known quadrature formula and its error terms. The error is then analysed for ... -
Quantitative analysis of collagen and elastic fibers in the transversalis fascia in direct and indirect inguinal hernia
(University of Nairobi.Department of Mathematics, University of Nairobi, 2002)PURPOSE: Our previous studies demonstrated structural and quantitative age-related changes of the elastic fibers in transversalis fascia, which may play a role in inguinal hernia formation. To verify whether there were ... -
A new isoflavone from stem bark of Millettia dura
(AJOLDepartment of Chemistry, University of Nairobi, 2003)A new isoflavone (7,3’-dimethoxy-4’,5’-methylenedioxyisoflavone) and three known isoflavones [isoerythrinin A 4’-(3-methylbut-2-enyl) ether, isojamaicin and nordurlettone] were isolated from the stem bark of Millettia dura ...