38 research outputs found
Bayesian analysis of right censored survival time data
We analyzed cancer data using Fully Bayesian inference approach based on Markov Chain Monte Carlo (MCMC) simulation technique which allows the estimation of very complex and realistic models. The results show that sex and age are significant risk factors for dying from some selected cancers. The risk of dying from these cancers is observed to progressively increase as age of patients increases. It is also observed that in order to allow for nonlinearity due to metrical covariate age, the semiparametric P-splines model is better than the model that categorizes age into various age groups
An Alternative Stratified Cox Model for Correlated Variables in Infant Mortality
Often in epidemiological research, introducing a stratified Cox model can account for the existence of interactions of some inherent factors with some major/noticeable factors. This paper aims at modelling correlated variables in infant mortality with the existence of some inherent factors affecting the infant survival function. A Stratified Cox model is proposed with a view to taking care of multi-factor-level that has interactions with others. This, however, is used as a tool to model infant mortality data from Nigeria Demographic and Health Survey (NDHS) with g-level-factor (Tetanus, Polio and Breastfeeding) having correlations with main factors (Sex, infant Size and Mode of Delivery). Asymptotic properties of partial likelihood estimators of regression parameters are also studied via simulation. The proposed models are tested via data and it shows good fit and performs differently depending on the levels of the interaction of the strata variable Z*. An evidence that the baseline hazard functions and regression coefficients are not the same from stratum to stratum provides a gain in information as against the usage of the Cox model. Simulation result shows that the present method produces better estimates in terms of bias, lower standard errors, and or mean square errors
DESIGN, CONSTRUCTION AND PERFORMANCE EVALUATION OF LOW COST ELECTRIC BAKING OVEN
The paper reports on the design and construction of a domestic electric basic oven. The aim of this research work is to improve on the already existing electric baking oven through the incorporation of a blower and interlock switch. The joining techniques and handling of the equipment for optimum usage was explained in details. The AUTOCAD design shows the pictorial views, lines and dimensions for its mass production purposes. The electric baking oven was put to test in order to determine its functionability and effectiveness through some food items. When the elecrtric baking oven was tested, higher efficiency is obtained when compared with the already existing one. Therefore, it can be deduced that the designed project is faster and thus baked effectively when compared with existing one. Keywords: Electric baking oven, blower, interlock switch, joining techniques, equipment, functionality, effectiveness
Sugar and alkaloid profiles of serendipity berry (Dioscoreophyllum cumminsii)
The study evaluates the chemical and physico-chemical composition of serendipity berry (Dioscoreophyllum cumminsii). The berries were separated into seed coat, gel and seed. The sugar and alkaloid profiles of the three components of these berries were analyzed. The predominant sugars were fructose and glucose. Fructose and glucose ranged from 0.61 to 3.47 mg/100g and 0.35 to 3.15 mg/100g respectively. The gel had higher sugar contents than the seed and the peel. Soladulcine was the predominant alkaloid in the seed and peel. Total alkaloids were 1.09 mg/100g in seed, 0.18 mg/100g in peel and traces of emetine in the gel. The alkaloid contents of the seeds were higher than the peels and the gel. Generally, the alkaloid contents in the three components of the berry were very low and could not cause any health problem when consumed. Serendipity berry is a promising fruit which could find its use in the production of juice and wine in the food industry. Keywords: Alkaloid, Fructose, Glucose, Serendipity berry, Suga
Morphological and morphometric studies of the aorta, pulmonary trunk, and heart of streptozotocin-induced diabetic Wistar rats
Micro-anatomical changes in the aorta, pulmonary trunk, and left ventricle of
Wistar rats were studied after the administration of streptozotocin. Twenty
adult Rattus norvegicus were randomly assigned into two groups (control and
diabetic) of ten rats each. Diabetes mellitus was experimentally induced in the
diabetic group of rats by daily intra-peritoneal administration of multiple doses
of 40 mg/kg streptozotocin dissolved in 0.1 M sodium citrate buffer for five
consecutive days. The control group was given the equivalent volume of citrate
buffer. The animals were monitored for four weeks after streptozotocin administration.
Post sacrifice, the left ventricle, aorta, and pulmonary trunk were
excised, weighed, and fixed by immersion in 10% formol saline. The tissues
were processed for paraffin embedding, and sections of 6 μm thickness were
produced and stained with H & E for general histological observations, and
Verhoeff-van Gieson elastic fibre stain to demonstrate elastic fibres in these
cardiovascular structures. The data obtained were analyzed with descriptive
and inferential statistics. Histopathological and morphometric examinations of
the stained sections showed a significant increase in the thickness of the tunica
intima of aorta (t = –7.49; df = 9; p < 0.05) and pulmonary trunk (t = –10.81;
df = 9; p < 0.05) in diabetic rats (14.59 ± 1.189 mm and 11.307 ± 0.863 mm,
respectively) when compared to that of the control group (3.62 ± 0.353 mm
and 3.22 ± 0.244 mm, respectively). In addition, the distribution of elastic and
collagen fibres was sparse in the hearts of the diabetic group when compared
to that of the control group. The findings of this study demonstrated that diabetes
mellitus might cause some alterations in the microanatomy of cardiovascular
structures
A Systematic Human Counting at Guest House using Sensing Device Technique
The application of vision detector using sensing device techniques is important in systematic counting of people both indoors and outdoors. This technique is broadly used in auditorium, lecture theatre and public market. In this paper, the technique uses a camera attached to an Android-based mobile phone which is then applied to capture images that are then transferred to a storage system via USB for image processing and counting. Also, a model for counting people indoors and outdoors is developed. Also, accurate human counting is observe
Corporate Image: A Strategy for Enhancing Customer Loyalty and Profitability
Organizations are nowadays concerned with managing their corporate image. There is a strong
positive correlation between people’s perceptions of a company and pro-corporate supportive
behaviour. In this study, past researchers on corporate image were incorporated to create a
platform for framework which identifies the variables of relationship between corporate image
and customer loyalty cum profitability. The study utilized descriptive statistics, bivariate
correlation and linear regression to investigate the impact of corporate image on customer
loyalty and profitability within the Nigerian service industry (banking). The study adopted the
research instrument of self-structured questionnaire which was in line with the reviewed
literature and focused on the main variables in the study. It was found in the model parameters
that physical environment, service offering and customer loyalty have significant impact on the
level of profitability. Thus, we can rightly conclude that the level of satisfaction among customers
tends to affect the service offerings and customer loyalty which has a direct link with corporate
profitability
NOVEL AIRFOIL DESIGN FOR SMALL HORIZONTAL AXIS WIND TURBINE: A PRELIMINARY RESULT
Various research efforts have been directed towards the design and re-design of wind turbine systems. This is in order to have more efficient, better performing and cost effective turbine systems. Based on this, efforts have been focused on wind turbine rotor design with emphasis placed on its aerodynamics. This is because the important criterion of a wind turbine rotor is the airfoil. It is the element that produces the forces that makes the turbine rotate. This research builds on existing knowledge and aims to further deepen knowledge in the field of wind turbine rotor design. The study designed and analysed a new airfoil for use in a small horizontal axis wind turbine. It employed the flow stage airfoil behaviour together with analytical software tools that include XFLR5, AirfoilPrep_v2.02.01, WT_Perf, and MATLAB.. Three well known and tested airfoils were employed and the coordinates were interpolated to create a new, more efficient and better performing small wind turbine rotor airfoil. The outcome showed the new airfoil performs better with good glide ratio over longer angle range, chord distribution and blade twist among other things. The parameters of the new airfoil were such that 10.17%, 26.49%, 6.26% and 45.0% of the chord characterised the maximum thickness and its position, and the maximum camber and its position respectivel
Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with extracts of Annona muricata
Microanatomical changes in the pancreatic islet cells of streptozotocin induced
diabetic Wistar rats were studied after treatment with methanolic extracts of
Annona muricata leaves. Thirty adult Wistar rats were randomly assigned into
three groups (control, untreated diabetic group, and A. muricata-treated diabetic
group) of ten rats each. Diabetes mellitus was experimentally induced in
groups B and C by a single intra-peritoneal injection of 80 mg/kg streptozotocin
dissolved in 0.1 M citrate buffer. The control rats were intraperitoneally
injected with an equivalent volume of citrate buffer. Daily intra peritoneal injections
of 100 mg/kg A. muricata were administered to group C rats for two
weeks. Post sacrifice the pancreases of the rats were excised and fixed in Bouin’s
fluid. The tissues were processed for paraffin embedding and sections of 5 μm
thickness were produced and stained with H & E, Gomori aldehyde fuchsin,
and chrome alum haematoxylin-phloxine for demonstration of the β-cells of
islets of pancreatic islets. Histomorphological and morphometric examination of
the stained pancreatic sections showed a significant increase in the number,
diameter, and volume of the β-cells of pancreatic islets of the A. muricata-treated
group (5.67 ± 0.184 N/1000 μm2, 5.38 ± 0.093 μm and 85.12 ± 4.24 μm3,
respectively) when compared to that of the untreated diabetic group of rats
(2.85 ± 0.361 N/1000 μm2, 2.85 ± 0.362 μm and 69.56 ± 5.216 μm3, respectively).
The results revealed regeneration of the β-cells of islets of pancreatic islet
of rats treated with extract of A. muricata. (Folia Morphol 2010; 69, 2: 92-100
RETINA FUNDUS IMAGE MASK GENERATION USING PSEUDO PARAMETRIC MODELING TECHNIQUE
The use of vascular intersection as one of the symptoms
for monitoring and diagnosis of diabetic retinopathy from
fundus images have been widely reported in literatures. In
this work, a new hybrid approach that makes use of three
different methods of vascular intersection detection namely
Modified cross-point number (MCN), Combine Cross Points
(CNN) and Artificial Neural Network (ANN) is hereby proposed.
Result obtained from the application of this technique
to both simulated and experimental shows a very high accuracy
and precision value in detecting both bifurcation and
cross over points. Thus an improvement in bifurcation and
vascular point detection and a good tool in the monitoring
and diagnosis of diabetic retinopathy