Sileshi Melesse

• University of KwaZulu-Natal

Background Sustainable Development Goal (SDG) 3.2 is to decrease the under-five mortality rate to under 25 per 1,000 live births by 2030. This is a critical objective for enhancing child health, especially in sub-Saharan Africa, where mortality rates persist at elevated levels. Objective This article evaluate progress made in Kenya towards Sustaina...

Background : Evidence from the progress made by the sub-Saharan Campaign SDG campaign shows that more spendings were required to meet the mark as the Target year 2030 approach faster. It is important to determine the association between health spending and these health outcomes to best inform policy. In this paper, we aim to understand and visualis...

Background: Reducing the under-five child mortality is vital to a nation’s development; global progress has been made in the past two decades. Nevertheless, substantial efforts in the Sub-Saharan Africa region are required to address critical risk factors to attain the Sustainable Development Goals (SDGs) by 2030. We aimed to identify the impact of...

Background Studies on approaches for combining information from related studies have been well-documented in the literature. However, limited research has been conducted to focus on the issue of combining parameter estimates in the context of under-five mortality. Objectives The objective of this study was to study the overall effect of socioecono...

Background An indicator called the under-five mortality rate makes it possible to compare deaths in several locations and groups of children of various sizes at once. Sub-Saharan Africa (SSA) still has a high under-five mortality rate that needs to be addressed before modifiable causes can be completely recognized. Objective The study investigates...

Background: This study aims to fill the information gap on factors affecting the time to return to normal HbA1c level and expected survival times in Ethiopia, as studies on these aspects are scarce, particularly in diabetic patients. Methods: A cross-sectional study was conducted on the patients with Diabetes Mellitus who followed the diabetic clin...

Child mortality continues to be a significant public health concern, particularly in the East African region. Understanding the factors associated with child mortality is crucial for developing effective interventions. This literature review aims to explore the relationship between various factors such as breastfeeding, sex of a child, type of plac...

Background Understanding the relationship between tuberculosis and the risk factors of tuberculosis is vital to be able to address them. Even though tuberculosis is curable and preventable, it remains a public threat, especially in low- and middle-income countries. There are more cases of men infected with tuberculosis compared to women. Methods T...

Larson and Dinse (1985) have introduced the mixture model as an additional competing risks model. In the same article, the authors have suggested that this model can be upscaled to handle the presence of missing failure causes in data. We respond to this proposal in this article and develop a regression model for analysis of data that comes with th...

Background One of the public health problems all over the world is tuberculosis. An important factor for human well-being is good health. Worldwide, there are more cases of men with tuberculosis than women. Therefore, identifying risk factors associated with tuberculosis among men is essential. This study uses a survey logistic regression model to...

Over the years, the standard regression analysis method for discrete time competing risks data has been to model the data with discrete time cause-specific hazards. While a few continuous time competing risks models have been proposed in the literature, it is a well documented fact that these models are not appropriate for application in discrete t...

The success of Bitcoin has spurred emergence of countless alternative coins with some of them shutting down only few weeks after their inception, thus disappearing with millions of dollars collected from enthusiast investors through initial coin offering (ICO) process. This has led investors from the general population to the institutional ones, to...

Background The CD4 cell count signifies the health of an individual’s immune system. The use of data-driven models enables clinicians to accurately interpret potential information, examine the progression of CD4 count, and deal with patient heterogeneity due to patient-specific effects. Quantile-based regression models can be used to illustrate the...

Quantile regression offers an invaluable tool to discern effects that would be missed by other conventional regression models, which are solely based on modeling conditional mean. Quantile regression for mixed-effects models has become practical for longitudinal data analysis due to the recent computational advances and the ready availability of ef...

Background: This study aims to make use of a longitudinal data modelling approach to analyze data on the number of CD4+cell counts measured repeatedly in HIV-1 Subtype C infected women enrolled in the Acute Infection Study of the Centre for the AIDS Programme of Research in South Africa. Methodology: This study uses data from the CAPRISA 002 Acu...

It is of great interest for a biomedical analyst or an investigator to correctly model the CD4 cell count or disease biomarkers of a patient in the presence of covariates or factors determining the disease progression over time. The Poisson mixed-effects models (PMM) can be an appropriate choice for repeated count data. However, this model is not r...

Background Lesotho is the country located in the Sub-Saharan region of Africa countries where under-five mortality (U5M) is still a big issue due to some significant social and demographic risk factors. Hence, the investigation of some social and demographic factors that are associated with the U5M, is a critical problem that needs due consideratio...

Background: The Infant Mortality Rate (IMR) in Sub-Saharan Africa (SSA) remains the highest relatively to the rest of the world. In the past decade, the policy on reducing infant mortality in SSA was reinforced and both infant mortality and parental death decreased critically for some countries of SSA. The analysis of risk to death or attracting c...

Background: One of the public health problems in developing countries is child malnutrition. An important factor for children's well-being is good nutrition. Therefore, the malnutrition status of children under the age of five is an important outcome measure for children's health. This study uses the proportional odds model to identify risk factor...

Beyond the effort provided on the population policy in Rwanda so far, extensive studies on factors that could prevent infant mortality (IM) should be done for more controlling the Infant mortality rate (IMR). This study presents an application of survival analysis to the infant mortality at the Kigali University Teaching Hospital (KUTH) in Rwanda....

Resampling technique as a way of overcoming instability in Cox Proportional hazard model is used for measuring the risk and related standard error for the infant mortality, given socio-economic and clinical covariates for mother and children at the Kigali University Teaching Hospital in Rwanda. Bootstrap and jackknife Cox proportional hazards mode...

In this paper, we modify the continuous time mixture competing risks model (Larson and Dinse, 1985) to handle discrete competing risks data. The main result of the model is an alternate regression expression for the cumulative incidence function. The structure of the regression expression for the cumulative incidence function under this model, and...

Linear mixed effects model offer great flexibility in modelling and analysis of between and within-subject variation, especially for repeated measures data. However, the routine use of these models with an assumption of normality for the random effects and within-subject errors in data with outliers is questionable, because they are sensible to tho...

Introduction The present study applies multiple events survival analysis to infant mortality at the Kigali University Teaching Hospital (KUTH) in Rwanda. Materials and Methods The primary dataset consists of newborns from KUTH recorded in the year 2016 and in the current paper, a complete case analysis was used. Two events per subject were modeled...

The effect of tree age and climatic variables on stem radial growth of two hybrid clones of Eucalyptus was determined using longitudinal data from eastern South Africa. The stem radius of was measured weekly as the response variable. In addition to tree age, average weekly temperature, solar radiation, relative humidity and wind speed were simultan...

Background Child malnutrition is the leading public health problem in developing countries. It is a major cause of child morbidity and mortality. Under-five children are the most vulnerable group for malnutrition. Body Mass Index (BMI) is a measure of nutritional status and is defined as the ratio of weight (kg) to squared height (m ² ). Studying t...

The aim of this study was to develop a model for prediction of the quality of tomato during storage. Two storage conditions (evaporatively cooled and ambient), four disinfection treatments (tap, anolyte, hot and chlorinated water) and three maturity stages (green, pink and red) were employed in this experiment. Using multivariate analysis, the prin...

Background The well-being of a child reflects household, community and national involvement on family health. Currently, the global under-five child mortality rate is falling faster compared to any time in the past two decades. However, the progress remained insufficient to match the Millennium Development Goal 4 targets especially in the Sub-Sahar...

Background: Although the economic conditions in Ethiopian households have recently improved, under-five mortality has remained one of the major problems in the country. Identification of the risk factors for under-five mortality is an important problem that needs to be addressed. This study aimed to estimate the effect of socio-economic and demogr...

Most of the simple logistic models show a highly significant association between the probability of tomato marketability and the predictor variables. Multiple logistic models predicted well most of the probability of tomato marketability using different quality attributes and were found to be significant at P< 0.001 level. The firmness, hue angle,...

This study was conducted to apply the logistic regression analysis to study the combined effects of continuous and categorical variables on the probability of marketability of tomato. Tomato fruits harvested at three maturity stages (green, pink, red) after pre-storage disinfections treatments (control, anolyte water, hot water, chlorinated water)...

Abstract This study presents some determinants of fertility for three countries in east Africa. It examines the role of the proximate determinants of fertility to total births during last five years before the surveys in Kenya, Rwanda and Tanzania. The study is based on the analysis of secondary data obtained from Demographic and Health Surveys in...

Growth of commercial forestry is highly dependent on the availability of fast-growing planting materials. Consequently, the efficient utilization of fast-growing plantations can greatly impact productivity. The objectives of this study were to evaluate variations in the growth potential of two clones and to estimate the average stem radial growth a...

Tree growth is influenced by environmental and genetic factors. Trees with different genetic material growing under the same environmental conditions have different growth pattern. Adequate management requires good understanding of factors affecting tree growth. The aim of this study is to determine the factors that influences stem radial growth of...

Because of growing wood consumption, pulp and paper demands, plantations of the fast-growing tree species, managed under short rotations, have a mounting significance for the sustainability of industrial wood raw material. Consequently, the efficient utilization of fast growing plantations can have an enormous impact on productivity. The study is b...

The study applied a combination of categorical and continuous explanatory variables via logistic regressions to model the probability of quality, defined as marketability, of tomato (Solanum lycopersicum L.) fruits subjected to different pre-harvest (biocatalyst application) and post-harvest treatments: (i) dipping in tap water, chlorinated water o...

FITTING THREE PARAMETER GROWTH CURVES USING A NONLINEAR MIXED EFFECTS MODELLING APPROACH Sileshi F. Melesse 1 School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg, South Africa. e-mail: Melesse@ukzn.ac.za and Temesgen Zewotir School of Mathematics, Statistics and Co...

This study attempted to explain the effect of combined pre and postharvest treatments [preharvest treatment (PHT) with a natural catalyst (ComCat®), disinfection and packaging (DP) and storage environment (SE)] on some quality parameters of stored tomato, using multifactorial statistics. The application of Wilk’s lambda (λ) test statistic to the da...

Due to increasing wood consumption and pulp and paper demands, plantations of fast growing tree species, have a growing importance for the sustainability of industrial wood raw material. Consequently, the efficient utilization of fast growing plantations can have a large impact on productivity. Adequate management requires good understanding of fac...

Understanding the relationship between stem radial growth and climatic conditions in plantation productivity is important to identify the climatic factors that most influence tree growth. This study aims to determine the climatic factors that most influence the stem radial growth of eucalypt trees plantation in the coastal Zululand area of South Af...

Incomplete block designs for a complete diallel cross (CDC) experiment known as method (2) of Griffing (1956) are proposed. These designs are derived by using mutually orthogonal Latin squares of order p, when p is a prime integer or power of a prime integer. With p inbred lines, the [p(p + 1)/2 − 1] degrees of freedom, for this method of Griffing,...

The incomplete block designs for complete diallel crosses are proposed for p parental lines, where p is a prime or power of a prime. These incomplete block designs are derived by using Latin squares and mutually orthogonal Latin squares designs of order p. The efficiency of these designs in comparison to randomized block designs is one.