Mathematical Analysis of a Diarrhoea Model in the Presence of Vaccination and Treatment Waves with Sensitivity Analysis

In this study, the diarrhoea model is developed based on basic mathematical modelling techniques leading to a system (five compartmental model) of ordinary differential equations (ODEs). Mathematical analysis of the model is then carried out on the uniqueness and existence of the model to know the region where the model is epidemiologically feasible. The equilibrium points of the model and the stability of the disease-free state were also derived by finding the reproduction number. We then progressed to running a global sensitivity analysis on the reproduction number with respect to all the parameters in it, and four (4) parameters were found sensitive. The work was concluded with numerical simulations on Maple 18 using Runge-Kutta method of order four (4) where the values of six (6) parameters present in the model were each varied successively while all other parameters were held constant so as to know the behaviour and effect of the varied parameter on how diarrhoea spreads in the population. The results from the sensitivity analysis and simulations were found to be in sync

Biodegradative activities of some gram- negative bacilli isolated from kerosene treated soil grown with cowpea (Vigna unguiculata)

The biodegradative activities of three Gram negative bacilli (Aeromonas hydrophila, Vibro parahaemolyticus and Actinobacillus sp) isolated from soil contaminated with kerosene and planted with cowpea was investigated. The isolates were identified using MicrobactTM ID 24E system for the identification of Enterobacteriaceae and common miscellaneous Gram negative bacilli (MGNB). 2kg of soil collected from University of Ilorin was placed inside transparent, drilled buckets. Physicochemical properties of the soil were recorded. The soil was contaminated with kerosene at different concentrations of 0ml, 7ml, 14ml, 21ml, 56ml, 112ml, 168ml and 224ml. The setup was laid out in a randomized complete block design with three replicates. Cowpea seeds of the variety Samaru-40 were cultivated and observed for eight weeks. The results indicated that kerosene contamination of soils significantly affected the growth parameters: germination percentage, time of germination, rate of germination, plant height, number of leaves, leaf area and root nodules. A negative interaction existed between the level of the contaminant and the growth characteristics measured. Their biodegradative activities were studied and confirmed by the change in the Total Petroleum Hydrocarbon (TPH) using gravimetric method. The biodegradative abilities of the isolates were compared by measuring the optical densities, total viable count, pH and emulsification activity. The results showed that the organisms did better as a consortium rather than singly. Aeromonas hydrophila had the highest biodegradative activity followed by Vibro parahaemolyticus and then Actinobacillus sp. The study recommends the use of Aeromonas hydrophila and consortium for more effective biodegradation.Keywords: Bacterial Biodegradation, Soil, Cowpea, Kerosene, Total Petroleum Hydrocarbo

IDENTIFICATION OF TSUNAMIGENIC EARTHQUAKE ZONES IN OCEANIC RIDGES AND TRENCHES

Tsunamigenic earthquakes have been known for their near and far field catastrophic impacts on coastal areas near oceanic ridges and trenches, as well as near tectonic faults in closed and semi-enclosed seas. Not all regions of oceanic ridges and trenches are tsunamigenic earthquake zones, but knowledge of the weighted sum of released earthquake energy and of the Gutenberg-Richter relation of the „a‟ and „b‟ parameters are needed to better identify them as to their potential for tsunami generation. The present analysis was undertaken in order to better identify tsunamigenic zones near oceanic ridges and trenches in the Mid-Atlantic, in the Pacific, in Chile, in Japan, near the Aleutians and along the Peru-Chile trench. The weighted sum of earthquake energy released and of the Gutenberg-Richter relation parameters were evaluated to identify tsunamigenic earthquake zones along these locations. The present analysis of the Gutenberg-Richter relation of the „a‟ and „b‟ parameters indicates that tsunamigenic earthquakes do not occur frequently along the Aleutian Trench, although the historic record supports that destructive tsunamis have occurred along this region in the past. Of the oceanic ridges, the results of the present analysis indicate that the Mid-Atlantic Ridge is the most active tsunamigenic zone, while of all the oceanic trenches, the Japan Trench is the most active

Evidence of basement controlled faulting of cretaceous strata in the Middle Benue Trough, Nigeria from lineament analysis of gravity data

The Bouguer anomaly map of part of the Middle Benue Trough, Nigeria, was used to investigate the genetic relationship between the basement and intra-sedimentary structures in the study area. This was with a view to establishing the evidence of possible basement controlled faulting of the Cretaceous strata. Regional-residual separation of the anomalies was carried out to produce the gravity maps associated with crustal masses at deep and intermediate depth layers. The derived maps were further processed to produce Horizontal Gradient Magnitude (HGM) maps that were used to infer deep seated structures and structures existing at intermediate depth layer of the study area. HGM maxima of the anomaly at various altitudes of upward continuation were used to highlight the locations and dip directions of subsurface structures as controlled from deep to shallow zones. The results of this study showed that the structures at different depth layers dominantly trend in the same direction (N-S, NNE-SSW and NE-SW) and that the deep seated faults reflect structurally in the overlying sedimentary column. It was therefore concluded that basement faulting might have influenced the structures in the overlying sedimentary rocks.Keywords: Cretaceous Sediments, Lineaments, Azimuth-frequency, Fault Propagatio

Evidence of basement controlled faulting of cretaceous strata in the Middle Benue Trough, Nigeria from lineament analysis of gravity data

The Bouguer anomaly map of part of the Middle Benue Trough, Nigeria, was used to investigate the genetic relationship between the basement and intra-sedimentary structures in the study area. This was with a view to establishing the evidence of possible basement controlled faulting of the Cretaceous strata. Regional-residual separation of the anomalies was carried out to produce the gravity maps associated with crustal masses at deep and intermediate depth layers. The derived maps were further processed to produce Horizontal Gradient Magnitude (HGM) maps that were used to infer deep seated structures and structures existing at intermediate depth layer of the study area. HGM maxima of the anomaly at various altitudes of upward continuation were used to highlight the locations and dip directions of subsurface structures as controlled from deep to shallow zones. The results of this study showed that the structures at different depth layers dominantly trend in the same direction (N-S, NNE-SSW and NE-SW) and that the deep seated faults reflect structurally in the overlying sedimentary column. It was therefore concluded that basement faulting might have influenced the structures in the overlying sedimentary rocks.Keywords: Cretaceous Sediments, Lineaments, Azimuth-frequency, Fault Propagatio