206 research outputs found

    Comparative Analysis of Stratified Randomized Response Models for HIV Seroprevalence Surveys

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    Seroprevalence surveys of HIV pandemic are highly sensitive especially in Africa. The objective of this study is to reach research frontier to devise a two-way randomized response model (RRM) in stratification and use same to estimate HIV seroprevalence rates in a given population and compare results with the existing seroprevalence rates. The randomized response techniques (RRT) guarantees the anonymity of respondents in surveys aimed at determining the frequency of stigmatic, embarrassing or criminal behaviour where direct techniques for data collection may induce respondents to refuse to answer or give false responses. The motivation was to improve upon the existing RRMs as well as to apply them to estimate HIV seroprevalence rates. Warner proposed the pioneering RRM for estimating the proportion of persons bearing a socially disapproved character. Quatember produced unified criteria for all RRTs, Kim and Warde proposed a stratified RRM and so many others. The proposed two-way RRM in stratification for HIV seroprevalence surveys was relatively more efficient than the Kim and Warde stratified estimator for a fixed sample size. The chosen design parameter was 0.7, using the criteria of Quatember who derived the statistical properties of the standardized estimator for general probability sampling and privacy protection. Furthermore, the model was used to estimate the HIV seroprevalence rate in a sampled population of adults 3,740 people aged 18 years and above attending a clinic in Kaduna, Nigeria using a sample size of 550. The findings revealed that HIV seroprevalence rate, as estimated by Model I, stood at 6.1% with a standard error of 0.0082 and a 95% confidence interval of [4.5%, 7.7%]. These results are consistent with that of Nigerian sentinel survey (2003) conducted by NACA, USAID and CDC which estimated the HIV seroprevalence in Kaduna State as 6.0%. Hence, the RRTs herein can serve as new viable methods for HIV seroprevalence surveys. Similarly, the result for model II show that, using the survey data, the model estimated the HIV seroprevalence rate as 8.74% with a standard error of 0.0134 and 95% confidence bands of [6.1%, 11.4%]. Accordingly, the sentinel projected seroprevalence rate, using the EPP Package, for the next ten years (2013) was 9.7%; very consistent with the 95% confidence interval. Hence, the RRTs herein can also serve as new viable methods for HIV seroprevalence surveys. Model II has a better chance of estimating HIV seroprevalence because it has higher privacy preservation

    Carriage rates of hepatitis B virus among individuals of different blood group systems and haemoglobin genotype

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    The study was conducted between September 2012 and May 2013, to determine the frequency of hepatitis B virus carriage among apparently healthy individuals of different blood groups and haemoglobin genotypes. Nine hundred and eighty (980) students and staff comprising of males and females, aged 15-39 years, participated in the study. Five millilitres of blood sample was collected, 3 ml of which was put in a plain container for hepatitis B screening, while 2 ml was put into anti-coagulated container for blood group and haemoglobin electrophoresis. Using hepatitis B immunoassay strip (Global source, Shenyang LTH Tech, China), hepatitis status of each subject was determined; blood group was determined using tube agglutination method, while haemoglobin genotype was determined by electrophoresis method. The overall sero-prevalence recorded in this study was 6.94%. Assessing the infection rate with respect to age and blood group, 15-19 year bracket has the highest rate 18(1.86%) and it was recorded among blood group individuals. Statistical analysis by Chi Square showed no significant difference in the rate of hepatitis B carriage with respect to ABO blood grouping system (X2= 0.3412, P> 0.05). The distribution of viral carriage rate among the Rhesus D positive individuals was statistically higher than the rate in Rhesus D negative subjects (X2= 4.321, P < 0.05). Higher frequency of the carriage was also recorded among the females 37(3.78%) than the males 31(3.16%). While Hb – AA individuals had the highest rate of 50(5.10%) of carriage, there was no case of infection among individuals with Hb – SS, Hb – SC and Hb –CC. Statistically, Chi Square test showed no significant difference in the rate of hepatitis B infection in relation to haemoglobin genotype (X2= 1.201, P> 0.05). In conclusion, individuals with pathological genotypes (Hb – SS, Hb – SC, and Hb – CC) were hepatitis B sero-negative. Also, the study recorded a significant link between hepatitis B and Rhesus D blood group system. Further investigation is recommended using more sensitive techniques to corroborate the present findings.  Keywords: Hepatitis B virus, carriage rates, blood group systems, genotype

    Machine Learning Approaches for Heart Disease Detection: A Comprehensive Review

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    This paper presents a comprehensive review of the application of machine learning algorithms in the early detection of heart disease. Heart disease remains a leading global health concern, necessitating efficient and accurate diagnostic methods. Machine learning has emerged as a promising approach, offering the potential to enhance diagnostic accuracy and reduce the time required for assessments. This review begins by elucidating the fundamentals of machine learning and provides concise explanations of the most prevalent algorithms employed in heart disease detection. It subsequently examines noteworthy research efforts that have harnessed machine learning techniques for heart disease diagnosis. A detailed tabular comparison of these studies is also presented, highlighting the strengths and weaknesses of various algorithms and methodologies. This survey underscores the significant strides made in leveraging machine learning for early heart disease detection and emphasizes the ongoing need for further research to enhance its clinical applicability and efficacy

    Adsorption of Methylene Blue using Activated Carbon Made from Watermelon Rinds

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    This work reports the possibility of using sustainable waste from watermelon rinds as a potential candidate for the removal of methylene blue (MB) from aqueous solution in batch mode. The adsorbent was characterized by FTIR and SEM where the FTIR analysis shows peaks at 3370 cm-1 that corresponds to –OH stretching vibration for lignin, pectin and cellulose, at 1728 cm-1 corresponds to –C=O stretching of esters, carboxylic acids, and as well peak in the range of 1350 – 1000 cm-1 which indicates stretching vibration of alcohols and carboxylic acids. The availability of hydroxyl and carboxyl groups enhance high MB uptake at lower pH. The SEM image of raw adsorbent shows no development of pores, but after carbonization the pores were developed due to escape of volatile groups during carbonization and activation process. Adsorption studies using batch mode were performed by varying adsorption parameters such as adsorbent dosage, contact time, pH of the solution and initial dye concentration. The maximum capacity of the adsorbent was found to be 0.4g dosage, pH 4, 20mg/L of initial MB concentration and 60 minutes contact time that removes maximum of 197.5 mg g-1. The results indicated that watermelon rind is a successful agricultural waste that could be utilized for sustainable removal of cationic dyes in aqueous solutions

    Effects of thermal treatment of some dietary feed ingredients on their digestibility and growth of common carp, Cyprinus carpio fingerlings

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    The purpose of the current study was to determine the effects of thermal treatment (autoclaving) of several dietary feed ingredients, including fishmeal, soybean meal, wheat bran, yellow corn, and barley, on the apparent digestibility coefficients ADCs, as well as the growth and feed efficiency of common carp, Cyprinus carpio fingerlings. The feed ingredients were autoclaved for 10 min at 121ÂşC and 15 psi in a laboratory autoclave. Two experiments were conducted, the first consisted of 11 diets, reference, and 10 experimental diets (reference was mixed with each raw or autoclaved test ingredient in a ratio of 70:30) to determine the digestibility of feed ingredients. The second experiment consisted of 8 diets, a control diet of raw ingredients and seven experimental diets were formulated, five of them in which one of the raw feed ingredients was replaced with the autoclaved one, the sixth in which three raw ingredients (wheat bran, yellow corn, and barley) were replaced together with the autoclaved ones, and the seventh in which all the raw ingredients were replaced with the autoclaved ones. The results of the first experiment presented that autoclaving significantly enhanced ADCs of dry matter, protein, and energy, of all feed ingredients except fishmeal. The results of the second experiment similarly presented that the thermal treatment significantly enhanced ADCs in the diets containing autoclaved soybean meal or wheat bran, yellow corn, and barley or all ingredients compared control diet. The growth and feed efficiency were better significantly in autoclaved soybean meal or all ingredients diets compared control diet. It is advised that plant-based ingredients, especially soybean meal, be thermally-processed to improve their nutritional value and lessen their environmental impact

    Geo additive Cox Models with Gaussian and Binomial Links for the Analysis of Wasting status of Nigerian Children

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    Malnutrition is associated with more than half of all children deaths worldwide. A study into geographical variability of nutritional status of children in Nigeria was observed from krigingand thecontinuous covariates weight for height (wasting) that exhibit pronounced non-linear relationships with the response variable was analysed. The Multiple Indicator Cluster Survey 3 (MICS3) data set contains several variables. Only those that are believed to be related to nutritional status were selected. All categorical covariates are effect coded. The child’s age is assumed to be nonlinear; the state is spatial effect while other variables are parametric in nature. Wasting is higher among children in the urban areas, the more rich the parents the more prevalence of wasting. Mother’s education is inversely associated with child’s wasting. Sex of the child is not significant with wasting and severe wasting is prevalent in the Northern region of the country. The study builds a statistical model that will help various health agencies in the country in developing a framework, policies and programmes that will improve child health care. Keywords: Wasting, Categorical data, Binomial,Gaussian, and Krigin

    Case report of challenges in the management of a rare ductal dependent complex congenital heart disease in a Nigerian tertiary hospital

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    Objective: Complex congenital heart defects are rare and may be difficult to define. They often require early surgery for palliation or correction. A lack of facilities and manpower to provide surgery in developing countries often results in mortality.Case report: A 6 month old male infant referred to our unit on account of failure to thrive, cyanosis since birth, easy fatigability and breathlessness. On examination he was small for age with tachycardia and a grade III pansystolic murmur at the left lower sternal edge. Chest radiograph revealed an “egg on side” cardiac appearance with cardiomegaly. Echocardiography confirmed the presence of d-transposition of the great arteries with a patent foramen ovale, large ventricular septal defect and atresia of the proximal main pulmonary artery. The child died while being prepared for referral to a centre for palliative surgery. Conclusion: Transposition of the great arteries with pulmonary atresia is an uncommon congenital heart disease. Early intervention with palliative surgery is necessary to prevent mortality.Keywords: Congenital heart disease; pulmonary atresia with ventricular septal defect; great vessel anomaly; echocardiograph

    EVALUATING MANAGEMENT CHALLENGES IN THE MOTIVATION OF EMPLOYEE-CONSULTANTS IN THE NIGERIAN CONSTRUCTION INDUSTRY

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    ABSTRACT:Management is faced with the task of motivating employee-consultants and creating high job satisfaction among them. Creating programs and policies that develop job satisfaction and serve to motivate employee-consultants takes time and money to create. When the management understands the benefits of job satisfaction and motivation in the workplace, then the investment in employee-related policies can be justified. The purpose of any motivation programme is to motivate the organization's employees to enable them work effectively. However, motivating employees is not an easy thing as what motivates employees differs among people. This paper is intended to establish management challenges in the motivation of Employee-Consultant in the Nigerian construction industry with a view to improving the motivation of employee-consultants. A calculated sample size of 108 construction and consultancy firms were randomly selected within Kaduna and Abuja metropolis. The research used the relative importance index (RII) to rank the challenges in order of importance. Amount of Fee paid (workers' wages) was identified to be the most significant factor that challenges the motivation of employee-consultants. Low availability of income generated was also identified as a major challenge. The research therefore suggest that management should seek other forms of motivating employee consultants such as New incentive schemes, such as flexible working hours, subsidies, loans and others, should be developed and implemented. Further research should be conducted to harness these important factors identified for the growth and development in the construction and consultancy firms.Keywords: Employee-Consultant, Motivation, Nigerian, Construction Industry, challenge

    Simulation of Area of Interest Management for Massively Multiplayer Online Games Using OPNET

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    In recent years, there has been an important growth of online gaming. Today’s Massively Multiplayer Online Games (MMOGs) can contain millions of synchronous players scattered across the world and participating with each other within a single shared game. The increase in the number of players in MMOGs has led to some issues with the demand of server which generates a significant increase in costs for the game industry and impacts to the quality of service offered to players. With the number of players gradually increasing, servers still need to work efficiently under heavy load and, new researches are required to improve the established MMOG system architectures. In dealing with a considerable scale of massively multiplayer online games, several client-server and peer-to-peer solutions have been proposed. Although they have improved the scalability of MMOGs in different degrees, they faced new serious challenges in interest management. In this paper, we propose a novel static area of interest management in order to reduce the delay and traffic of Hybrid P2P MMOGs. We propose to use OPNET Modeler 18.0, and in particular the custom application to simulate the new architecture, which required the implementation of new nodes models and behaviors in the simulator to emulate correctly the new architecture. The scenarios include both client-server and hybrid P2P system to evaluate the communication of games with (125, 500, and 1000) peers. The simulation results show that area of interest management for MMOGs based on the hybrid P2P architectures have low delay and traffic received compared with MMOGs based on client-server system

    Evaluation of Scalability and Communication in MMOGs

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    Massively Multiplayer Online Games (MMOGs) can involve millions of synchronous players scattered across the world and participating with each other within a single shared game. One of the most significant issues in MMOGs is scalability and it is impact on the responsiveness and the quality of the game. In this paper, we propose a new architecture to increase the scalability without affecting the responsiveness of the game, using a hybrid Peer-to-Peer system. This mechanism consists of central servers to control and manage the game state, as well as super-peer and clone-super-peer to control and manage sub-networks of nodes sharing common regions of the game world. We use the OPNET Modeler to simulate the system and compare the results with client/server system to show the difference in delay and traffic received for various applications such as remote login, database, HTTP, and FTP sessions which are all part of an MMOG system. We use four scenarios for each system to evaluate the scalability of the system with different number of peers (i.e.125, 250, 500, and 1000 peers). The results show that the hybrid P2P system is more scalable for MMOGs when compared with client/server system
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