395 research outputs found
Hazard Perception and Demand for Insurance Among Selected Motorcyclists in Lagos, Nigeria
This study examines hazard perception effects on the demand for insurance withspecial focus on motorcycle riders in Lagos state. For this purpose, the researchershave been able to examine selected hazard perception determinants and theireffects on the insuring attitude and desire of motorcycle riders. An explanatoryresearch design was employed and a convenience sampling type of the nonprobabilitysampling technique was adopted. Data was gathered by interviewsconducted at motorcycle parks along the Lagos-Badagry expressway. The sampleconsisted of 126 respondents made up of commercial motorcycle riders within thesample areas. Data collected was analysed using multiple regression technique.The study was able to establish some level of contributory linkage between hazardperception and demand for motorcycle insurance. The findings show that whiledread and trust both appeared to have significant effect, publicity and controllabilityboth have positive contributory effect; furthermore, choice expressed an inverserelationship with demand for insurance among the motorcycle riders. The studytherefore recommends pre-loss and post-loss measures among the motorcycleriders so that unforeseen motorcycle risks can be managed. Also, insurancecompanies should endeavour to invest more on enlightening the motorcycle riders in order to lessen their dread of loss outcome, and thus, design policy that can instil trust in motorcycle riders in insurance as a loss control measure
BENZENE ORAL BIOAVAILABILITY ASSESSMENT USING IN VITRO DIGESTION MODEL IN COMBINATION WITH CELL CULTURE METHODOLOGY
The bioavailability of volatile organic compounds (VOCs) in a given situation often remains challenging to assess, and the lack of standard methods for introducing VOCs into in vitro bioassays can lead to poorly defined bioavailable concentrations. As a result, in vitro assays normally conducted in wells of cell culture plates for risk assessment of volatile and hydrophobic organic chemicals (VHOCs) have always faced significant experimental difficulties due to high volatility and high hydrophobicity. This compromises the true exposure concentration by: (i) causing the amount of test substances in the test medium to decline, (ii) limits the quality of toxicological responses and their extrapolation, and thus, can lead to interpretational errors. In the research herein, a dosing method was developed to assess the bioavailability of benzene (that served as a model for VHOCs) in aqueous tests and to better characterize exposure estimates for an improved risk assessment during in vitro biotests. This study hypothesizes that (1) benzene bioavailability to intestinal porcine enterocyte cell line (IPEC-1 cells) can be partially explained by phase partitioning, as measured by freely dissolved concentration that drives the diffusive uptake into the cell membranes, (2) benzene equilibrium partitioning between the donor and the cell membranes is dependent upon energetic state of the chemical concentration in the partitioning donor, which describes its chemical activity. Silicone polydimethylsiloxane (PDMS) was used as the partitioning donor for passive dosing in transwell plates. The buffering capacity of the donor compensates for routine loss against depletion processes during the toxicity tests, resulting in stable exposure concentrations of benzene freely available to cells at relatively constant chemical activity. For IPEC-1 cells in the passive dosing tests, the median effective concentration (EC50) was 4.82 mg/L. The obtained median effective activity (Ea50) value is within the chemical activity range (0.01– 0.1) for baseline toxicity of several hydrophobic chemicals reported in the literature. Cell inhibition ranged from 9.6 ± 2% to 97.7 ± 0.8% for freely dissolved concentrations of benzene, which ranged from 0.6 to 5.4 mg/L after 24 h exposure. The spiking tests result in an ECSpike-50 projected to be greater than 5.4 mg/L, (highest spiked concentration) and reduced test sensitivity of benzene to IPEC-1 cells. This study introduces a new effective approach to passive dosing and demonstrates the utility of passive dosing over solvent spiking for in vitro toxicity testing of hydrophobic chemical (log Kow ˂ 4.6) with high volatility. This has fundamental implications for a better understanding of the interactions between VHOCs exposure to humans and the toxic effects on the human intestine to help set remediation objectives and further the improve future risk assessment and standard setting for VHOCs
Effects of direct-fed lactic acid bacteria on weight gain and ruminal pH of two south African sheep breeds
A ruminant’s digestion depends on microbial degradation of feed rather than endogenous enzyme degradation as in most monogastric animals. The study was conducted to assess the effects of Lactic Acid Bacteria (LAB) strains administered as direct-fed microbials on weight gain and ruminal pH of Damara and Meatmaster sheep breeds. Sixty-four Damara and Meatmaster sheep breeds [Damara males (36.6 } 8.3 kg); Damara females (28.9 } 6.9 kg); Meatmaster males (24.6 } 3.4 kg); Meat master females (21.5 } 3.1 kg)] were subjected to a 30-day trial and divided into five treatment groups as follows: pellets with no antibiotic and no probiotics administered (T1); pellets with no antibiotics, only Lactobacillus rhamnosus SCH administered (T2); pellets with no antibiotics, only Lactobacillus rhamnosus AF3G administered (T3); pellets with no antibiotics, with the combination of Lactobacillus rhamnosus SCH and Lactobacillus rhamnosus AF3G, administered (T4); pellets fortified with antibiotic and no probiotic administered (T5). The animals were fed on commercial pellets fortified with or without antibiotics. Animals were each weighed, and rumen fluids were collected using a stomach tube, and pH was read immediately, before and at the end of the trials. Data obtained were subjected to analysis of variance using SPSS version 4.0. The results showed that the effect of treatment, sex and some of their interactive effects were significant (p <0.001) on the body weight of sheep irrespective of breed. The effect of treatments revealed that the animals in the combination of probiotics gained more weight than those in other groups. Damara breed had a heavier body weight than Meatmaster while males were 6 kg heavier relative to females (p <0.001). Only breed was significant (p <0.05) on weight gained. Treatment (p <0.05), breed (p <0.001) and their interactive effect (p <0.05) were significant on ruminal pH. The highest pH value was 7.27 for the T5 group and 7.37 for the Damara breed. Results suggest that LAB may have beneficial effects on the growth performances of sheep and therefore may be suitable as future growth promoters in sheep production, as they don't have any harmful residues compared to antibiotics
Investigation of Suitable Foundation for Storey Building in Surcharged Swampy Soil (A Case Study of Lagos State)
In Lagos, Southwestern Nigeria, the land area has been developed such that there are insufficient land spaces for building construction. It therefore becomes imperative that construction of storey buildings is inevitable to accommodate buildings within the limited land spaces. The percentage of swampy – land is high, thus restricting people to build on the little available land with little or no convenience and to effectively utilize the available land, there is need to improve the large percentage of swampy–land for construction of storey building with suitable foundation. This study therefore focused on determination of soil properties for building foundations at 1.5km South of Lagos – Epe Expressway Oloja, Ibeju Lekki Local Government Area of Lagos State.Soil samples were collected from open pits in five different locations within the study area. The undisturbed samples were obtained at depths of  3m and  were carefully transported by putting each of the samples in polythene bag and then kept in sealed container before being transported.The particle size distribution analysis of selected soil samples from the study area was carried out in accordance with the provision of BS1377: Part 2, 1990. Compaction test, Unconfined compression Strength (UCS) test and bearing capacity test were all carried out on the collected soil samples.The results of the tests carried out on the selected soil samples showed that the soil in the study area was largely made up of silty-clay material with OMC and MDD ranging from 9.60-12.5% and 1.82-1.91 g/cm3 respectively; UCS values between 22.24 – 56.67 kN/m2 and allowable soil bearing capacity ranging from 90.95 to 106.26 kN/m2. It is recommended that Raft foundation be used for bungalows while beam/slab raft should be used for structures that have 2-5 storeys and pile foundation for structures above 5 storeys in order to cater for silt-clay nature of the soil and to prevent differential settlement in future. Keywords: Swampy Soil, consolidation, foundation, storey building
CORPORATE GOVERNANCE AND HUMAN RESOURCE MANAGEMENT IN NIGERIA’S DOWNSTREAM PETROLEUM SECTOR
The emergence of a ‘new world economy’ makes it imperative for corporate entities to adjust their corporate values, practices and internal processes. This paper explored the interrelatedness of selected corporate governance practices and human resource management outcomes. The paper relied on established corporate management theories as a platform for empirical consideration of selected issues relative to four established players in Nigeria’s downstream petroleum sector. A descriptive method was adopted and data was collected via a survey of 112 respondents. Contextual arguments were captured to achieve a robust appreciation of issues affecting individual participation and operations of corporate entities. The study found that there is a significant relationship between corporate governance practices and human resource management outcomes. Requisite conclusions and recommendations were provided in the light of empirical and theoretical findings
Using Extreme Value Theory to Model Insurance Risk of Nigeria's Motor Industrial Class of Business
Extreme losses have been recorded in Nigeria insurance companies due to motor insurance class claims; Nigeria Insurance market being a developing one requires building the confidence of the public to subscribe to their products. Nigeria’s motor industrial insurance claim data for five insurance companies in a two year period is modelled in this paper with extreme value theory (EVT) to estimate the Value-at-Risk (VaR), where VaR gives estimate of the minimum amount of claims an insurance company would pay in a given period of time. The time series plot was obtained which aimed at capturing the trend of the claims over the two-year period, the mean excess plot was obtained which helped to determine threshold and the shape of the distribution in the tail area. The returns were then fitted in a Generalized Pareto model (GPD), a similar model that would have been used is the Generalized Extreme Value model (GEV) but the GPD is used in this study because it describes what happens in the tail area of the distribution and not just the maximum tail. A linear Q-Q plot reveals that parametric model fits the data well. VaR estimate was finally obtained using the extreme value method and other two methods of Historical and Gaussian at 5% confidence interval. The three methods of estimating VaR were compared and the empirical result shows that extreme VaR is most suitable to calculate VaR as compared to the Historical and Gaussian method
Fat fraction provides classification and treatment response assessment of metastatic lymph nodes for patients with radio-recurrent prostate cancer
Lesion size threshold is the most common imaging feature used to assess response to therapy. Size as an imaging feature has its limitations. Quantitative imaging biomarkers (QIBs) could identify subtle microstructural changes prior to morphological changes. In this study, we explored the use of novel whole-body MRI (WB-MRI) QIBs for nodal disease characterisation and treatment response monitoring in radio-recurrent prostate cancer (rPC). We showed signal fat fraction could discriminate between positive and negative nodes and that it can be used for response monitoring
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