Abdel-Salam Gomaa Abdel-Salam

• Associate Professor in Statistics
• Professor (Associate) at Qatar University

In this paper, we adopt a Gaussian prediction model for non-stationary time series, then we discuss four transformation techniques: Generalized Optimal Wavelet Decomposition Algorithm (GOWDA), Hilbert Huang transform (HHT), Detrending based on Echo State Networks (DESN), and Kolmogorov-Zurbenco (KZ) filter. GOWDA is an algorithm that runs the conti...

Introduction: Sleep quality among university students is crucial for academic success and overall well-being. This study investigated the discrepancies between subjective and objective sleep assessment in university students and explored associated factors. Method: A total of 19 male university students (mean age: 25 ± 3 years; mean weight: 79.36 ±...

The COVID-19 pandemic has highlighted the crucial role of health sector decision-makers in establishing and evaluating effective treatment and prevention policies. To inform sound decisions, it is essential to simultaneously monitor multiple pandemic characteristics, including transmission rates, infection rates, recovery rates (which indicate trea...

(1) Background: Dentistry is innately stressful and demanding. However, the extent of perceived chronic stress and the contributing factors within the dental practice at Primary Health Care Corporation (PHCC) in Qatar are largely unknown. (2) Methods: This study is quantitative, hypothesis-testing, correlational, and cross-sectional, using a simple...

This article introduces and examines a hierarchical model of influences that identifies the variables affecting the watchdog role of journalists at three levels: the societal (press freedom and democracy), the organizational (media ownership), and the individual (editorial autonomy and perceived influences) on a global scale. Using data from 27,567...

In this article, we suggest that the ideological cultural forces explain the differences in journalism practices in Western and Muslim majority countries (MMC). It is argued that the norms, values, and the deep political culture of the West and MMC have been materialized leading to different types of journalism practices. The statistical analysis o...

Introduction Online education has become a crucial component of teachers’ professional development, and universities incorporate innovative pedagogical approaches to enhance teachers’ training. These approaches have proven invaluable, particularly during the COVID-19 pandemic. This study investigates the impact of online versus face-to-face learnin...

Background Across higher education, student retention, progression, and graduation are considered essential elements of students’ academic success. However, there is scarce literature analyzing these attributes across health professions education. The current study aims to explore rates of student retention, progression, and graduation across five...

With the COVID-19 outbreak, schools and universities have massively adopted online learning to ensure the continuation of the learning process. However, in such setting, instructors lack efficient mechanisms to evaluate the learning gains and get insights about difficulties learners encounter. In this research work, we tackle the problem of predict...

The study aimed to investigate students’ final grades in a linked course or chain course to determine any effect on students’ academic performance in their next linked course. Courses with high D, F, and W grades were selected with their subsequent linked courses to form a chain so that each chain consisted of two courses or more. More specifically...

Purposeː In swimming, elbow extension and flexion are among the most important movements involved in the front crawl upper body propulsive phase. Therefore, this study aimed to investigate the characteristics of young swimmers in relation to 200-m performance. Methods: 16 male swimmers (Age: 13.13 ± 2.06y; Body Mass: 60.88 ± 18.58 kg; Height: 164.7...

There are several reasons for student academic underperformance, such as academic, personal, and social factors students face when transitioning from high school to higher educational institutions. In this review paper, a systematic literature review is conducted based on the PRISMA strategy; the aim is to analyze the factors that lead to academic...

Background: Vitamin D is considered a potent modulator of the immune system, albeit its role in COVID-19 infection is a matter of debate. The present study aimed to estimate the association between serum vitamin D levels and COVID-19 among people in Qatar. Methods: This case-control study, approved by the Institutional Review Board of Primary He...

This chapter provides an assessment of the impact of the major political and institutional factors on establishing new businesses in the State of Qatar in the long run using the autoregressive distributed lag (ARDL) model. In particular, we are interested in studying the following political and institutional factors: political stability, rule of la...

Worldwide, university student support services facilitate student performance, contribute to students' success, and increase students' chances of degree completion. Student support services programs' success depends on students' help-seeking behavior. This study explores the help-seeking behavior of Foundation Program and Undergraduate students at...

In this work, both the cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts have been reconfigured to monitor processes using a Bayesian approach. Our construction of these charts are informed by posterior and posterior predictive distributions found using three loss functions: the squared error, precautionary, and...

During the outbreak of the Covid-19 pandemic, universities were forced to adopt technology and collaboration tools to reinforce online teaching and sustain their operations. This radical change pushes universities, researchers, educators, practitioners and decision makers to explore the perceptions of students and provide high quality online teachi...

UNESCO reports enrollment in higher education in the Arab and Gulf Cooperation Council region doubled from 5.1 million in 2000 to 10.7 million in 2015. Despite significant budgets and the world’s lowest teacher-to-student ratio, higher education in this region is plagued by student underachievement. This study identifies academic underachievement f...

PURPOSE The main objective of the study was to explore the effect of the exam period on sleep, physical activity and cognitive functioning among physical education students during COVID-19 lockdown. METHODS Twenty-one senior male students from the physical education department voluntary participated in the study. ActiGraph GT9X Link was used for sl...

This study aimed to describe the development and psychometric properties of a questionnaire for Muslim couples and families based on how couples view and experience marital and family issues. A questionnaire was developed based on relevant literature and fine-tuned by a panel of experts. The questionnaire was administered to a sample of 1212 hetero...

Various factors influence the students' perception of universities and university image. This study explores five factors affecting university image among Graduate Alumni. Surveys, administered to 597 graduate alumni were assessed to determine Graduate Alumni perspectives toward their university. Findings revealed that the key factors that impacted...

In light of recent COVID-19 pandemic, universities had to cope by resorting to online learning without previous preparation. This paper tries to investigate students’ satisfaction with online learning. The literature review identified seven factors that influence satisfaction (quality, interaction, information technology, academic experience, compr...

A novel approach to link the environmental stresses with the COVID-19 cases is adopted during this research. The time-dependent data are extracted from the online repositories that are freely available for knowledge and research. Since the time series data analysis is desired for the COVID-19 time-dependent frequent waves, here in this manuscript,...

Many studies were conducted for fitting models using parametric and non‐parametric techniques; in fact, their fits may be biased and have inflated the estimated variances when the model is misspecified, respectively. Thus, semi‐parametric techniques are used for fitting models as they combine the advantages of parametric and non‐parametric fits. In...

Potential introduction of VAT in Qatar may have a significant pass-through effect on inflation rates. Nevertheless, using the Harmonized Index of Consumer Prices at constant tax rates (HICP-CT), in this article the authors find that the pass-through effect on prices is going to be low, at 2.17%, even though the proposed VAT rate is 5%. They conclud...

One of the notes worthy problems in analysis of clinical and observational studies is missing data and nonresponse from patients. Turning a blind eye to the missing behavior may provide biased results with overestimated standard errors. The potential impact of the problem may even have more severe impression in estimating health-related quality of...

Corona virus (CoV) is a group of viruses with non-bifurcated, single-stranded, and positive-sense RNA genomes. Apart from infecting several economically significant vertebrates (such as pigs and chickens), it is reported in the recent literature that six main types of CoVs infect the human hosts and cause lung infections. In animals, CoVs cause sev...

Streamflow is associated with several sources on nonstationaries and hence developing machine learning (ML) models is always the motive to provide a reliable methodology to understand the actual mechanism of streamflow. e current research was devoted to generating monthly streamflows from annual streamflow. In this study, three different ML models...

Streamflow is associated with several sources on nonstationaries and hence developing machine learning (ML) models is always the motive to provide a reliable methodology to understand the actual mechanism of streamflow. The current research was devoted to generating monthly streamflows from annual streamflow. In this study, three different ML model...

Metals and coating materials, with best material properties are highly desired in the field of engineering to control the stresses and strains, that play important role in design strategies. The crankshaft, an important part of tank engine, depends on the cranking mechanism in the internal combustion engine. The function of the crankshaft is to con...

Premise: Climate change is having major impacts on alpine and arctic regions, and inter-annual variations in temperature are likely to increase. How increased climate variability will impact plant reproduction is unclear. Methods: In a 4-year study on fruit production by an alpine plant community in northern Sweden, we applied three warming regi...

During the current COVID-19 pandemic, decision makers are tasked with implementing and evaluating strategies for both treatment and disease prevention. In order to make effective decisions, they need to simultaneously monitor various attributes of the pandemic such as transmission rate and infection rate for disease prevention, recovery rate which...

Background: The Bene-Anthony Family Relations Test (BAFRT) is one of the most widely used measures of family dynamics seen from a child's perspective. However, the most common issue surrounding this test is the lack of accurate normative scores for use with non-white ethnic groups. The purpose of this study was to examine the BAFRT's reliability a...

A control chart is one of the statistical process techniques that is used to monitor different processes. Some processes are characterized by functions or profiles, and a profile is a functional relationship between the dependent and independent variable(s) used to monitor the quality of the process. Several research studies were conducted on linea...

Research has established that class attendance and High School Grade Point Average (HSGPA) play a significant role in student academic success in higher education. The study uses census data and records of 969 undergraduate students at Qatar University to investigate the impact of HSGPA, attendance, and socio-demographic factors on academic perform...

Worldwide there is an increase in competition between higher education institutions seeking to ascertain their position in the world ranking, resulting in universities introspectively reflecting on their image and student satisfaction. This is especially the case in the Gulf Cooperation Countries, where there has been significant growth in higher e...

This paper proposes a new asymptotically valid stationary bootstrap procedure to obtain multivariate forecast densities in unrestricted vector autoregressive models. The proposed method is not based on either backward or forward representations, so it can be used for both Gaussian and non-Gaussian models. Also, it is computationally more efficient...

The generalized linear mixed model (GLMM) becomes very popular in profile monitoring, especially when the production processes follow nonnormal distribution. In most of the real‐life applications in industry, medicine, biology…and so on researchers assume that the response variable follows a Bernoulli or Binomial distribution. The majority of previ...

Abstract Background: The global burden of cancer has exponentially increased over the last few years. In 2018 alone, approximately more than half of the 18.1 million individuals who had cancer succumbed to it. Lung cancer cases and fatalities are particularly on the rise. Therefore, exploring the factors surrounding lung cancer mortality is of utm...

Profile monitoring is one of the methods used in statistical process control (SPC) to understand the functional relationship between response and explanatory variables by tracking this relationship and estimating parameters. SPC is done in two phases: In Phase I, a statistical model is created and its parameters estimated using historical data. Pha...

Background Exploring spatial patterns in the context of cancer disease mapping (DM) is a decisive approach to bring evidence of geographical tendencies in assessing disease status and progression. However, this framework is not insulated from spatial confounding, a topic of significant interest in cancer epidemiology, where the latent correlation b...

The Exponentially Weighted Moving Average (EWMA) and Cumulative Sum (CUSUM) control charts have been used in profile monitoring to track drift shifts that occur in a monitored process. We construct Bayesian EWMA and Bayesian CUSUM charts informed by posterior and posterior predictive distributions using different loss functions, prior distributions...

The Covid-19 outbreak of 2020 has required many governments to develop mathematical-statistical models of the outbreak for policy and planning purposes. This work provides a tutorial on building a compartmental model using Susceptibles, Exposed, Infected, Recovered and Deaths status through time. A Bayesian Framework is utilized to perform both par...

Background: Novel coronavirus (COVID-19) is a new strain of viruses that originated in China. In December 2019, a strange case of pneumonia was reported in Wuhan, which then was diagnosed to be COVID-19. In Singapore, the first positive case was reported on January 23, 2020. Aim: This study aims to study the recovery time from COVID-19 in Singapore...

Background Novel coronavirus (COVID-19) is a new strain of viruses that originated in China. In December 2019, a strange case of pneumonia was reported in Wuhan, which then was diagnosed to be COVID-19. In Singapore, the first positive case was reported on January 23, 2020. Aim This study aims to study the recovery time from COVID-19 in Singapore b...

Soft drink consumption has become a significant public health concern that is associated with various adverse health outcomes. We aim to examine the association between soft drink consumption and aggressive behavior among adolescents. We used open access data from 79 studies in 64 countries, including 263,890 adolescents aged 12-18 years who comple...

Skewness plays a vital role in different engineering phenomena so it is desired to measure this characteristic accurately. Several measures to quantify the extent of skewness in distributions have been developed over the course of history but each measure has some serious limitations. Therefore, in this article, we propose a new skewness measuring...

Aggregation of large databases in a specific format is a frequently used process to make the data easily manageable. Interval-valued data is one of the data types that is generated by such an aggregation process. Using traditional methods to analyze interval-valued data results in loss of information, and thus, several interval-valued data models h...

Aggregation of large databases in a specific format is a frequently used process to make the data easily manageable. Interval-valued data is one of the data types that is generated by such an aggregation process. Using traditional methods to analyze interval-valued data results in loss of information, and thus, several interval-valued data models h...

Climate change is already having a major impact on alpine and arctic regions, and inter-annual variations in temperature are likely to increase. In a four-year study focusing on fruit production by an alpine plant community in northern Sweden, we applied three different warming regimes over the years. Treatments consisted of (a) a static level of w...

Are countries with a free press less corrupt than countries where the press is partly or completely unfree? Our empirical investigation finds evidence of a significant relationship between higher levels of press freedom and lower levels of corruption with other variables being equal. Furthermore, we provide evidence that while democracy deters corr...

Are countries with a free press less corrupt than countries where the press is partly or completely unfree? Our empirical investigation finds evidence of a significant relationship between higher levels of press freedom and lower levels of corruption with other variables being equal. Furthermore, we provide evidence that while democracy deters corr...

Profile monitoring is defined as the act of utilizing regression and quality control techniques to monitor the functional relationship between a response variable and one or more regressors. Most of the previous studies focused either on parametric modeling of profiles or assumed the response variable followed a normal distribution, but that is an...

Nonparametric tests are generally used where the data does not follow a normal distribution. Spearman rank‐order correlation is a nonparametric statistical technique for measuring the relationship between two ordinal variables or rank‐ordinal correlation. The biserial correlation is used if both variables are measured on an interval/ratio scale, bu...

Data are classified into two categories: nonmetric and metric. Nonmetric data are also termed as qualitative and metric as quantitative. Metric data can be measured on two different types of scale, i.e. interval and ratio. The data measured on interval and ratio scales are also termed as interval data and ratio data, respectively. This chapter inve...

This chapter discusses different types of assumptions associated with the survey procedures, questionnaire, data, and analysis that a researcher should understand. Data cleaning is the first step of data analysis in any survey research. One of the most important assumptions in survey research is that the questionnaire is reliable. A questionnaire i...

This chapter helps readers to understand the required nonparametric assumptions, different nonparametric tests, how to perform those using IBM Statistical Package for the Social Sciences (SPSS) software, and what should be done if there is any violation for these assumptions. The common assumptions in nonparametric tests are randomness and independ...

Usually, the parametric tests are known to be associated with strict assumptions about the underlying population distribution. For almost all of the parametric tests, a normal distribution is assumed for the variable of interest in the data under consideration. Testing for randomness is a necessary assumption for the statistical analysis. The rando...

This chapter presents the introduction of Statistical Package for Social Sciences (SPSS) software for the beginners along with different types of data management procedures that can be carried out in SPSS. Data cleaning process is an important step in any research as it significantly affects the findings. One should check for the consistency of dat...

Bioinformatics and Biostatistics Applications in Tobacco Smoking Research The Bioinformatics, Biostatistics, and Genomics are examples of the multidisciplinary and interdisciplinary blend of scientific fields merging two or more specialties help express robust conclusion of respective research activity. The selected Research Topic “Bioinformatics...

(Diaz-Vicario & Sallan, 2017; Hundeloh & Hess, 2003). Understanding parents’ perceptions of school safety can be an important issue that will guide teachers (Bosworth, Ford, & Hernandaz, 2011), administrators and staff (Heisterkamp, & Fleming, 2011), and legislators (Elliott, 2015) in setting strategies to enhance school safety and school climate....

The process structures of manufacturing industry are efficiently modeled using linear profiles. Classical and Bayesian set-ups are two well appreciated schemes for designing control charts for the monitoring of process structures. Mostly in profiles monitoring the independent variables along with the process parameters are assumed fixed. There are...

The links between the use of tobacco and health risks are well known. Most of the younger smokers reside in Asia which includes Qatar, the focus country of this study. Cigarette smoking among children is rising at an alarming rate worldwide including Qatar. As youth make up a significant percentage of the population and to achieve the health object...

Tobacco smoking is widespread behavior in Qatar and worldwide and is considered one of the major preventable causes of ill health and death. Nicotine is part of tobacco smoke that causes numerous health risks and is incredibly addictive; it binds to the α7 nicotinic acetylcholine receptor (α7nAChR) in the brain. Recent studies showed α7nAChR involv...

Cancer is a significant health problem in the Middle East and global population. It is well established that there is a direct link between tobacco smoking and cancer, which will continue to pose a significant threat to human health. The impact of long-term exposure to tobacco smoke on the risk of cancer encouraged the study of biomarkers for vulne...

When process data follow a particular curve in quality control, profile monitoring is suitable and appropriate for assessing process stability. Previous research in profile monitoring focusing on nonlinear parametric (P) modeling, involving both fixed and random-effects, was made under the assumption of an accurate nonlinear model specification. La...

This study introduces a new bowling scoring system and testsits consistency with the current scoring system with respectto preserving player placements. A comprehensive simulation study for different scenarios; two-player, three-player, and four-playergames performed. The simulations empirically quantify thelikelihood of experiencing concordant res...

Background: Coronary heart disease (CHD) is a main cause of morbidity and mortality globally. High levels of cholesterol are considered a major risk factor of CHD. This study sought to find out the prevalence of high cholesterol levels among Qatar University female students. Methods: Total cholesterol (TC), high-density lipoprotein (HDL) cholestero...

In this bioinformatics study we analyzed the functional motifs and structural features of regulatory regions of OPN3, a member of the guanine nucleotide-binding protein (G protein)-coupled receptor super-family, which is involved in cancer and drug resistance. Our analyses showed major differences in the two OPN3 promoters located at the 5’-side of...

Dust samples were collected from 38 naturally ventilated houses for 12 weeks using wiping glass plates. Effects of three variables in each of the two studied groups were evaluate: proximity to traffic density (main- and side-roads), cigarettes smoking (smoking and non-smoking), and houses’ age (old and new). No significant differences were identifi...

β1,4-Galactosylransferases are a family of enzymes encoded by seven B4GALT genes and are involved in the development of anticancer drug resistance and metastasis. Among these genes, the B4GALT1 shows significant variations in the transcript origination sites in different cell types/tissues and encodes an interesting dually partitioning β-1, 4-galac...

Background: The B4GALT1 (β-1,4-galactosyltransferase) gene, overexpressed in human cancers is highly implicated in tumor progression and metastasis. Used as a prototype in genomic analyses, it shows significant variations in the transcript origination sites in normal and cancer tissues. Little is known on the regulation of B4GALT1 transcription and...

The development of cisplatin resistance in human cancers is controlled by multiple genes and leads to therapeutic failure. Hypermethylation of specific gene promoters is a key event in clinical resistance to cisplatin. Although the usage of multiple promoters is frequent in the transcription of human genes, the role of alternative promoters and the...

In standard analyses of data well-modeled by a nonlinear mixed model, an aberrant observation, either within a cluster, or an entire cluster itself, can greatly distort parameter estimates and subsequent standard errors. Consequently, inferences about the parameters are misleading. This paper proposes an outlier robust method based on linearization...

Mixed models are powerful tools for the analysis of clustered data and many extensions of the classical linear mixed model with normally distributed response have been established. As with all parametric (P) models, correctness of the assumed model is critical for the validity of the ensuing inference. An incorrectly specified P means model may be...

The research presented in this paper characterizes the impact of a wet pavement surface and rainy weather conditions on driver perception-reaction time (PRT) at the onset of the yellow indication on the approach to a high-speed signalized intersection. An in-vehicle differential Global Positioning System was used in a controlled field environment....

The adaptive exponentially weighted moving average (AEWMA) control chart has the advantage of detecting balance mixed range of mean shifts. Its performance has been studied under the assumption that the process parameters are known. Under this assumption, previous studies have shown AEWMA to provide superior statistical performance when compared wi...

Profile monitoring is an approach in quality control best used where the process data follow a profile (or curve). The majority of previous studies in profile monitoring focused on the parametric (P) modeling of either linear or nonlinear profiles, with both fixed and random effects, under the assumption of correct model specification. More recentl...

The objectives of this study were to evaluate the genetic diversity of the North American soybean (Glycine max L.) accessions using Random Amplified Polymorphic DNA (RAPD) molecular marker; and to evaluate RAPD markers to be used in soybean as genetic markers and improve such techniques as suitable strategies for soybean germplasm characterization....

Profile monitoring is an approach in quality control best used where the process data follow a profile (or curve). The majority of previous studies in profile monitoring focused on the parametric modeling of either linear or non-linear profiles, with both fixed and random-effects, under the assumption of correct model specification. Our work consid...

Adequate spacing and design of access to crossroads in the vicinity of freeway ramps are critical in the safety and traffic operations of the freeway, crossroad, and properties near interchanges. Research attempted to develop a methodology to evaluate the safety impact of different access-road spacing standards. Results clearly demonstrate the shor...