ASSET:An International Journal (Series B)}

AN EXACT LINEAR OPERATION FOR THE MULTIPLIER METHOD

2012-10-03T10:51:32+01:00

An exact linear Control operation is constructed for the minimization of non linear (quadratic) function using the conjugate gradient method. The convergence profiles for some numerical examples in the class of the control problems considered are examined and the effects of two update methods are equally examined. The scheme is found to converge at very low iterations. It was found that updating per circle ensures faster rate of convergence than per iteration.

CYTOLOGICAL RESPONSE OF VIGNA UNGUICULATA AND VIGNA VEXILLATA ACCESSIONS TO COLCHICINE TREATMENT

2012-10-03T10:51:32+01:00

Induction of polyploidy was achieved in two out of ten accessions of Vigna unguiculata and three of five accessions of V. vexillata that were subjected to colchicine treatment. Mitosis and meiosis were found to be normal in the control plants of all the accessions with somatic chromosome counts of 2n = 22 and meiotic counts of n = 11, which resulted in normal tetrad formation. Meiotic chromosome counts of 2n = 4x = 44 were made for the putative colchiploids which were characterized by meiotic irregularities such as univalents, multivalent associations, precocious separation of chromosomes, laggards, scattering of chromosomes at the poles and unequal distribution of chromosomes to the poles. The meiotic irregularities accounted for the reduced pollen fertility, high pollen size variation and formation of abnormal tetrads observed in the putative colchiploids.

RECENT REPORTS ON CHROMOSOME COUNT IN SOME NIGERIAN SPECIES OF ASTERACEAE

2012-10-03T10:51:32+01:00

Chromosome numbers are reported for some species of four genera of the tribe Cichorieae, some species in the genus Vernonia (Vernonieae) and the genus Aspilia (Heliantheae) collected from different parts of Nigeria. Fluctuations in current and previous counts were observed and presumed to be associated with chromosomal mechanism such as polyploidy and anuploid decrease, leading to evolution of species in the family Asteraceae. Species with first report of chromosome numbers are indicated.

EFFECTS OF 2-WEEK VITAMIN C SUPPLEMENTATION IN OCCUPATIONALLY LEAD EXPOSED ARTISANS FROM A MECHANIC VILLAGE IN ABEOKUTA, NIGERIA

2012-10-03T10:51:32+01:00

This study investigated the physiological and biochemical effects of leaded products especially gasoline in occupationally exposed artisans. The correlation between blood lead levels and some biochemical parameters and the ameliorative effects of Vitamin C were also determined. Plasma levels of Vitamin C, urinary excretion of lead, activities of the enzymes: Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), Glutamic-Oxaloacetic transaminase (GOT) and Glutamic-Pyruvic transaminase (GPT), with blood pressure, urine pH and specific gravity in relation to blood lead levels were determined in 32 artisans and 15 control before and after Vitamin C regimen. Compared to the control, the before Vitamin C administration, blood lead levels, urinary excretion of lead and the activities of the enzymes (ACP, ALP, GOT and GPT) were significantly higher while plasma Vitamin C was lower (P<0.05) in the artisans. There was also a positive correlation, which was statistically significant (P<0.01) between blood lead levels and the biochemical parameters except urine lead levels and activity of ALP. After a 2-week Vitamin C therapy, blood lead levels and the activities of the enzymes (ACP, GOT and GPT) were significantly reduced (P<0.05) in the artisans. Increased significantly, (P<0.05) were plasma Vitamin C, urinary excretion of lead and ALP (only in panel beaters). Positive correlation was observed between blood lead levels and ACP, GOT and GPT while negative correlation was observed between blood lead levels and urinary excretion of lead and ALP. The correlation was however statistically insignificant. It was however observed that before and after Vitamin C supplementation, blood pressure, urine pH and specific gravity were not significantly affected. These results indicated that exposure to leaded products affects mainly biochemical parameters and that they may be ameliorated by a daily dose of Vitamin C, especially when the artisans can not be removed from their sources of lead exposure.

METAL CONTENT AND PHYSICOCHEMICAL PROPERTIES OF SOME NIGERIAN BEVERAGES

2012-10-03T10:51:32+01:00

The quality of representative samples of 21 commonly consumed beverages in Nigeria was assessed based on their elemental composition (Na, K, Mg, Mn, Pb, Ca, Fe, Cu and Zn) and physicochemical properties (pH, sugar content (brix), density and alcohol content). The metal concentrations determined by atomic absorption spectroscopy (AAS). Soft drinks, fruit juice and wines were found to be acidic based on their pH values, which ranged from 3.19 – 3.64, 3.09 – 3.73 and 3.45-3.73 respectively. The range for Na, K, Mg, Mn, Pb, Ca, Fe, Cu and Zn ions concentrations in all samples analyzed were 9.88 – 1473.50, 1.53 – 2656.20, 1.78 – 564.40, 0.01 – 4.15S, 0.03 – 0.41, 2.15 –123.85, 0.32 – 5.24, 0.005 – 3.720 and 0.008 – 1.83 mg/L respectively. Malt drinks were found to be a good source of Mg²⁺ion (225.80-564.40mg/L). Fruit juice was found to be rich in K, Mg, Ca, Fe and Cu. Soft and malt drinks are also good sources of Na, K, and Mg among their respective brands. Soft drink was found to contain the highest level of Pb (0.41mg/L) among all the samples analyzed. All the samples analyzed except Ogogoro contained low level of Cu²⁺ion.

MUTAGENIC EFFECT OF AQUEOUS LEAF EXTRACT OF MORINDA LUCIDA (BENTH) ON ALLIUM CEPA (L) CHROMOSOMES

2012-10-03T10:51:32+01:00

Mitotic studies were carried out on onion roots treated with different concentrations of raw leaf extract of Morinda lucida, onion roots initiated on water served as control. Chromosome aberrations such as polyploidization, chromosome breakage, laggards and non-congression of chromosomes at telophase were observed in the dividing cells of onion roots treated with 0.5kg/L concentration of the leaf extract. There was no chromosome aberration observed in the roots treated with 0.1kg/L, 0.2kg/L and 0.4kg/L concentrations of the leaf extract and the control. Results obtained imply that high concentration of the leaf extract of M. lucida is capable of inducing chromosomal aberrations in Allium cepa. Low concentrations (£ 0.2kg/L) of the leaf extract are therefore suggested for treatment of ailments in traditional medicare.

EXPERIENCE WITH FINITE DIFFERENCE AND FINITE ELEMENT MODELLING IN THE SEDIMENTARY FORMATION OF NORTH-WESTERN NIGERIA

2012-10-03T10:51:32+01:00

Groundwater flow in the sedimentary formation of North-Western Nigeria was simulated with the aid of borehole data obtained from some 20 locations fairly distributed within the aquifer formation. The aquifer was modeled, in turn, using the Finite Difference Method (FDM) and the Finite Element Method (FEM), with appropriate initial and boundary conditions. The Finite Difference model employed is that developed by Pricket and Lonnquist (1971), where the sets of equations are solved by the Modified Iterative Alternating Direction Implicit Method, while the matrix solver technique adopted for the FEM was that of the Conjugate Gradient Method. Comparisons of output results were made between FDM and FEM in graphical formats for the steady state conditions as well as with the field data. The simulated results were found to compare favourably with field data, with the FEM giving a better response to excitation. The models were thereafter used to predict the effect of pumping on hydraulic heads from the base year 2000 to year 2030. The FDM and FEM results indicated the necessity of investigating borehole data at some locations where computed values differed appreciably from field values. These locations included boreholes 13, 14, 15, 18 and 19, representing Bulassa LIBC, Kurdula, Tangaza, Ruawuri and Safla, respectively. The outcome of the simulation exercise however suggests that the FEM is a more reliable modeling tool in view of its versatility, flexibility and accuracy.

IN SITU POPULATION EVALUATION OF THAUMATOCOCCUS DANIELLI (BENTH.)

2012-10-03T10:51:32+01:00

The sweetener plant, Thaumatococcus daniellii (Benth.) is a common plant found growing wild and domesticated in the rain forest zone of South-Western Nigeria. The plant is of diverse economic importance to the natives; the leaves and the stalk are used locally for various purposes and most importantly the protein based sweetener thaumatin in the seed aril is of immense economic value at the international market. The study involved the evaluation of sample populations of T. daniellii in four identified sites – located in Ekiti and Osun States, South West Nigeria. In each site, random population sampling using 1m² quadrant was done. Individual plant parameters: stalk height (cm), stalk girth (cm), leaf blade length (cm), leaf blade width (cm) and petiole length (cm) were scored for. Mean population density ranged from 52 + 33 (cm) to 117 + 4.67 (cm). Highly significant difference (P < 0.01) was observed for stalk height, stalk girth and leaf blade width in both between and within sites (populations). While insignificant differences were recorded for blade length and petiole length in both inter-and intra-population situations.

SOLAR RADIATION AS A MEANS OF WATER DISINFECTANT TO PREVENT TYPHOID FEVER

2012-10-03T10:51:32+01:00

The effect of solar radiation as a means of water disinfectant was conducted in this study. Fresh cultures of clinical isolates of Salmonella typhi strains identified by the standard methods were used. Preparations of aqueous suspension of S typhi were done in transparent plastics, glass bottles and metal basins and were covered with either transparent and/or translucent polytene bags and were exposed to sunlight using standard procedures. The suspensions were analyzed aseptically at 0,3,6,24,27 and 30 hours of incubation. The solar intensity for each experimental day was obtained. Controls were maintained for each test batch. The results of the study showed that S. typhi strains in metal basins and glass bottles with transparent polytene cover died out completely during the first 3 hours (10.30-13.30 hours) of exposure of the suspension to sunshine. The average temperature range during the experimental period was between 320C to 38.50C.The period of most rapid decline in S.typhi cells in this study corresponded with the peak of solar intensity (2,046kj/m2) rather than temperature. Therefore, exposure of water contaminated with S.typhi to solar radiation in transparent containers for at least 3 hours on a bright sunny day will render the water innocuous and thus preventing typhoid fever.

COPPER, IRON, LEAD AND NICKEL ACCUMULATION BY FUNARIA HYGROMETRICA IN INDUSTRIAL AND RESIDENTIAL AREAS OF KANO-MUNICIPALITY, KANO-NIGERIA

2012-10-03T10:51:32+01:00

Metal concentrations (Cu, Fe, Pb and Ni) were determined in fun aria hygrometric a collected from industrial and adjacent residential areas of Kano-Nigeria using Atomic Absorption Spectrophotometer with an air acetylene flame. These areas have been modified by the increase of industrial activities and extensive road net work. The mean concentration of these elements in the zones ranged between 0.13_ 0.14µgg^-1in Ni to 2.17-105.01µgg^-1for lead; 52.51-151.67µgg^-1for iron and3.56-4.51µgg^-1for copper. Their varying concentrations may be due to their prevalence in the industrial and residential areas of the municipality.

FACILE SYNTHESES OF DI-HYDROXY AND AMINO HYDROXY PURINES

2012-10-03T10:51:32+01:00

The syntheses of 2-amino-6-hydroxy-8-( chloroalkyl ) purines and 2,6-dihydroxy-8-( chloroalkyl ) purines are reported. These novel compounds have been characterized using IR, UV» max , m.pt., and elemental analysis. The structural relationships between these compounds and previously used dihydroxy and amminohydroxy purines have also been discussed.

MICROBIAL RISK OF HAND MEASURED, REBAGGED POWDERED MILK

2012-10-03T10:51:32+01:00

Hand measured powdered milk and industrially packed powdered milk sold in four major markets(Kuto, Omida, Sapon, and Adatan) in Abeokuta were sampled for the presence of microorganisms. The microbial load was different from one milk to the other and ranged from 2.0 x 10⁴ cfu/ml to 1.6 x 10⁸cfu/ml. The probable numbers of coliform bacilli were between 50 to 70 cells in 100ml. Different fungi were isolated. All the powdered milk samples examined harboured Bacilli sp, Streptococcus spp, and Micrococcus sp, while hand measured powdered milk samples harbored Staphylococcus aureus, Pseudomonas sp, and Escherichia coli in addition. The role of the handler, the packaging nylon, as well as the contaminated environment to which the milk is exposed to during re-bagging probably play a vital role in the increase contamination of the milk.

TRACE METALS IN WATER FROM OLOGE LAGOON, LAGOS, NIGERIA

2012-10-03T10:51:32+01:00

The concentrations of Fe, Mn, Cu, Zn, Cd, Pb, and Ni were determined in water of Ologe lagoon on a bimonthly intervals between January 1997 and December 1998. The recorded heavy metal concentrations (except iron) were either significantly lower or within the safety limits of published averages for freshwaters; recommended standards by the EC, Canada, and USSR for the use of fisheries and aquatic life. A higher concentration of Fe reflects the natural sources due to the geology of the catchment soil. Variations in the concentrations of heavy metals in water may be due to local differences in current velocity and distance from the shore line (from sewage source of the residential sector). The level of industrialisation in the study area is very low; hence, contribution of heavy metals from industrial sources on the heavy metal status of the lagoon is minimal.

STEADY-STATE PROBABILITY ALGORITHM FOR A SINGLE-SERVER QUEUING SYSTEM

2012-10-03T10:51:32+01:00

A single-server queuing process is investigated. Using the assumptions of exclusiveness of events, randomly-distributed task duration and independence of the task duration of the length of time a task takes, the characteristics of a single server queue with space limits are investigated. An algorithm that uses the steady-state behaviours of a stochastic system is developed and implemented in Pascal language in this paper.

HYDRODYNAMIC INTERACTIONS BETWEEN RIVERS AND AQUIFERS: IMPLICATIONS ON ENVIRONMENTAL FLOW IN OGUN RIVER BASIN, NIGERIA

2012-10-03T10:51:32+01:00

Ogun river, a major river in southwestern Nigeria was studied to determine the interaction between the surface and groundwater in the river system. This was aimed at assessing the contribution of groundwater to environmental flows in the river system. The studies revealed that during the dry months, the effluent condition of the river makes it to receive discharges from groundwater at both the upper and lower reaches. This contribution is essential to maintain the ecology of the river. The study found the assessment useful for planning for environmental flow in the river system.

THERMAL DIFFUSIVITY ESTIMATES IN THE CHAD BASIN, N.E. NIGERIA-IMPLICATIONS FOR PETROLEUM EXPLORATION

2012-10-03T10:51:32+01:00

Estimates thermal diffusivities, Kappa, K of horizons drilled for hydrocarbons in the Chad basin, NE Nigeria obtained using density log tended to agree with those obtained from temperature-time data, with scatter in the first estimates seen as random fluctuations, while underestimation by the second are attributed to lack of quality data. Trend of Kappa, K across the horizons is interpreted as suggesting common source for the intrusives. Pressure-induced Kappa, K variations are estimated to be negligible, while those induced by temperature are significant. Rapid cooling of intrusions is argued to impact hydrocarbons maturation in manners that may not preclude their discovery.