A comparison of cancer classification methods based on microarray data.

Masters Degree. University of KwaZulu-Natal, Pietermaritzburg.Cancer is among the leading causes of death in both developed and developing countries. Through gene expression profiling of tumors, the accuracy of cancer classification has been enhanced, leading to correct diagnoses and the application of effective therapies. Here, we discuss a comparative review of the binary class predictive ability of seven classification methods (support vector machines, with the radial basis kernel (SVM(RK)), linear kernel (SVM(LK)) and the polynomial kernel (SVM(PK)), artificial neural networks (ANN), random forests (RF), k-nearest neighbor (KNN), and naive Bayes (NB)), using publicly-available gene expression data from cancer research. Results indicate that NB outperformed the other methods in terms of the accuracy, sensitivity, specificity, kappa coefficient, area under the curve (AUC), and balanced error rate (BER) of the binary classifier. Thus, overall the Naive Bayes (NB) approach turned out to be the best classifier with our datasets

Constraints and Growth Potentials of Micro and Small Enterprises: Case from Mekelle City

This study examines the constraints and growth potentials of micro and small enterprises. To undertake this study primary data were collected through well-structured and self-administered questionnaire to a sample of 85 micro and small-scale enterprises operated in Mekelle City. In order to explore the relationship between the explanatory variables with the dependent variable different econometric models like multiple regression to examine the growth of MSEs is associated with diffrent constraints and logit model to analyzes how and to what extent the operators’ socio-economics characterstics affect the income growth potential of enterprises were applied. The study result indicated that micro and small enterprises employment growth was significantly affected by constraints like crrent capital, current employment level, start up employment level, access to business services, and by motivation of the enterprises. Moreover, age,sex, experience access to finance and motivation of the enterprises affect growth potential of enterprises income. Therefore, these results highlight that the growth of MSEs in the study area are highly influenced by the specified business constraints. Keywords: Growth Potential, MSEs, and Constraint

Isolation and structure elucidation of halogenated metabolites from Portieria hornemannii and Portieria tripinnata

The red marine algal genus, Portieria, is known to produce a number of potent cytotoxic compounds with anticancer potential. The most important anticancer lead produced by this genus is the compound halomon. Unfortunately, the lack of sufficient quantities of this compound hampered its further development. Two Portieria species, Portieria hornemannii and Portieria tripinnata, are found along the South African coastline. Recent studies, based on DNA analysis, suggest that Portieria hornemannii may in fact be divided into several cryptic species. The current project is part of a larger study designed to investigate the use of secondary metabolites to identify new marine algal species. In this study 1H NMR profiles of the organic extracts of selected Portieria spp were compared in order to identify new species. Selected compounds were then isolated and characterised as potential chemotaxonomic markers. Four halogenated monoterpenes were isolated from Portieria hornemannii. Two of these were new compounds 4-(3-bromo-4-chloro-4-methylpentyl)-3-chlorofuran-2(5H)-one, which were isomers of each other. The two known compounds had been previously isolated from Portieria hornemannii samples off the Madagascar coast. These compounds could prove to be useful as chemotaxonomic marker compounds, as they have never been isolated from any other species of marine algae. Three known halogenated monoterpenes were isolated from Portieria tripinnata. These compounds had been previously isolated from different species of marine algae and therefore, could not serve as chemotaxonomic marker compounds for this species of marine alga. Further work needs to be done on Portieria tripinnata, with regards to its chemistry, as it is a species of marine algae that has not been previously researched

Exploration for Groundwater Aquifers, using Vertical Electrical Sounding (VES) method, in Wad Hamid area – River Nile State, Sudan

Geo-electrical measurements using the Vertical Electrical Sounding (VES) method was utilized in determining aquifer characteristics of Wad Hamid area. Three geologic units wererecognized in the area; Quaternary deposits, CretaceousSandstoneFormation and the Basement Complex rocks. 122 VES using the Schlumberger configuration were acquired for the study area. A maximum half electrode spacing of 900 m was utilized for data acquisition. All these soundings were processed using IX1Dsoftware. Geo-electric sections were constructedfrom which the aquiferous layers were delineated.Hydraulic parameters (hydraulic conductivity and transmissibility) were computed at the existing borehole and VES site

Factors that Influence Women in Selected Zongo Communities in Ghana into Skin Bleaching

The study analysed the factors that influence women in selected Zongo communities (Aboabo, Nima, Sawaba, Asawasi, Madina) in the country into skin bleaching. A sample size of fifteen (15) women who were selected through the purposive sampling technique was used to conduct the study. Interviews (semi-structured interview guide) were used to collect the data necessary for study. The data collected was analysed thematically. They bleach their skins for many reasons including the desire to sustain their marriages, the attempt to treat acne and also as a result of influence from peers among others. It was therefore recommended that the National Commission for Civic Education (NCCE), Food and Drugs Authority, the government and other responsible agents should take up the responsibility of educating Ghanaians on the dangers of skin bleaching. Keywords: Zongo women, Skin bleaching DOI: 10.7176/RHSS/9-10-03 Publication date:May 31st 201

The impact of energy on sustainable economic development in Uganda

Includes bibliographical references (leaves 280-293).Energy is a very important resource for national development. Uganda's energy mix comprises mainly biomass, petroleum products and electricity. Biomass is the main source of energy, contributing 92.3%. Petroleum contributes 6.3% and electricity 1.3% of the total energy consumption. The contribution of other forms of energy; wind, solar energy and biogas is negligible. Biomass is mostly used in households and small-scale industries. Petroleum and electricity are used in large-scale industries and in the commercial sector. It was envisaged that this study will be an important input into the National Vision, developed by the Ministry of Finance Planning and Economic Development, for the national development to the year 2025

Performance Analysis of Best Relaying Protocol Selection with Interferences at Relays

In this paper, we investigate the performance of selecting the best protocol between amplify and forward (AF) and decode and forward (DF) in multiple relay networks with multiple interferences at relays. In the selection scheme, the best protocol between AF and DF is selected depending on the comparisons of signal-to-interference and noise ratio (SINR) for all source-relay links. All relays measure the received SINR to decide forwarding signal or not. When SINR is above a certain threshold then DF is used otherwise AF is used. Particularly, we develop an accurate mathematical model for best relaying protocol by considering the effect of interferences to our scheme. Firstly, we derive the asymptotic closed form expression for the symbol error rate (SER) for the system under study. Also we derive an upper and lower bound of symbol error rate and show how they were tight with exact SER. Furthermore an approximate expression for the outage probability is derived. Numerical results are finally presented to validate the theoretical analysis with a different number of relays

Effect of tube inclination angle on the thermal and fluid dynamic performance of flat tube heat exchanger

At the present time, the performance of finned and flat tube heat exchangers (HEs) has become a very important issue in the thermal industrial sector. Finned-and-flat tube heat exchangers have gained great interest from many researchers due to their role in any thermal engineering system. Some geometrical and process parameters such as fin spacing, tube spacing, tube inclination angle, etc. affects the performance of fin-and flat tube heat exchangers. Significant number of research have been done to study the effect of such geometrical and process parameters. However, the effect of flat tube inclination angle on the thermal-hydraulic performance of fin-and-tube HE is not fully examined. Thus, the aim of this study was to investigate the effect of flat tube inclination angle, air velocity and tube configuration on the thermal and flow characteristics of compact fin-and-flat tube heat exchangers. A series of experimental and numerical investigations were carried out to evaluate the influence of the aforementioned parameters on the thermal-hydraulic performance between the tube bundles. Moreover, Response Surface Methodology (RSM) was used to determine the optimum parameter condition for the fin-and–tube HE. The range of the parameters considered in the study were tube inclination angle from 0˚ to 150˚, inlet air flow velocity from 1.8 to 3.8 m/s and tube configuration (inline and staggered). For the experiments, the wind tunnel available at the Faculty of Mechanical Engineering, UMP was used. The wind tunnel was equipped with a blower of capacity 50 W, flow straightener, test section and measuring sensors. Twelve plate fin and nine flat tube heat exchangers test sections were designed and manufactured at various inclination angles and configurations. Temperature, velocity, and pressure measurements were recorded at various positions in the test section as well as before and after the test section. For the numerical analysis, the CFD commercial software called ANSYS FLUENT-15 was used to solve the Navier-Stoke and energy equations together with proper turbulent equations. The parameters are similar to the experimental investigation. The experiment and numerical analysis used Nusselt number, pressure drop, and area goodness factor to evaluate the thermal-hydraulic performance of fin-and-flat tube heat exchangers. The major findings showed that flat tube inclination angle has significant impact on the heat transfer enhancement. However, the results from both experimental and numerical analysis revealed that increasing the tube inclination angle from 0˚ to 90˚ augments the convective heat transfer coefficient. While 120˚ and 150˚ provide thermal performance close to 60˚ and 30˚, respectively. The average deviations of Nusselt number between experimental and numerical results were 5.42% and 4.44% for inline and staggered configurations respectively. Moreover, due to the air flow blockage caused by inclining the tube angle, the pressure drop increases dramatically for all cases studied. From all acquired results, the best thermal performance occurred at 0˚, while 90˚ provided the minimum thermal performance. Therefore, inclining the tube is beneficial for enhancing the heat transfer performance but is not beneficial in term of pressure drop as it requires higher pumping power. The developed correlations from the RSM can predict experimental data with average deviation of 2.78% for Nu for both configurations. Moreover, it can predict the numerical data with average deviation of 0.554% and 0.92% for inline and staggered configuration, respectively. The optimum parameters are found to be with high air velocity and low tube inclination angle which provide maximum heat transfer enhancement and low-pressure drop penalty. Thus, it is recommended for the design of fin-and-flat tube HEs