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Mathematical Analysis of a Malaria model with vaccination, treatment and vector control using Sterile-insect technique
Get PDFIn this work, a mathematical model for malaria transmission is developed using a system of nonlinearordinary differential equations. The model incorporates three control strategies: vaccination, treatment,and sterile insect technique. Analytical results demonstrate that the malaria-free equilibrium is both locally and globally asymptotically stable when the basic reproduction number, R0 is less than one, and unstable when R0 > 1. The existence of an endemic equilibrium is investigated, and conditions for the occurrence of forward or backward bifurcation are derived. Numerical simulations and graphical illustrations are provided to demonstrate the disease dynamics under various control scenarios. The findings reveal that the combined application of all three control measures is more effective in reducing malaria transmission than any individual or pairwise combination of interventions
A Mathematical Analysis of Tuberculosis Transmission Using a Two-Age Group Compartmental Model
Get PDFIn this study, a two-age-group compartmental model for tuberculosis transmission is developed and an alyzed, distinguishing between individuals below 10 years and those above this age. The model includes key epidemiological features such as reinfection within both age groups and the transition of treated individuals back to full susceptibility, representing realistic post-treatment outcomes. Essential analytical properties like non-negativity, existence, and uniqueness of solutions are established to confirm the model’s biological validity. Equilibrium analysis identifies both disease-free and endemic steady states, and the basic reproduc tion number, R_0, is derived using the next-generation matrix method. Local stability analysis indicates that the disease-free equilibrium is asymptotically stable when R_0 < 1, suggesting effective disease control, while instability occurs when R_0 > 1, resulting in disease persistence. Additionally, the global stability of both equilibrium states is rigorously proven-employing the Metzler matrix method for the disease-free case and a Lyapunov function for the endemic state-demonstrating the model’s strong dynamical behavior. Sensitivity analysis of R_0 identifies parameters that significantly impact tuberculosis transmission dynamics, offering in sights for targeted intervention strategies. Scenario analyses, supported by three-dimensional plots, illustrate how variations in parameters influence R_0 and the spread of infection. Numerical simulations conducted in Python validate the analytical findings, indicating an increase in immunity as individuals age from under 10 to above 10 years, while higher contact rates among children considerably enhance transmission potential. This study provides a deeper understanding of age-dependent tuberculosis dynamics and offers relevant implications for disease control policies across different age groups
Relationship between pH and antioxidant capacity of selected locally available vegetables
Get PDFIn recent times, there have been controversies on the consumption of alkaline foods; with some authors suggesting that consistent consumption of acidic foods may lead to long-term health challenges, while consumption of alkaline foods will support health and help the body to remove the stress of an acidic lifestyle. Fruits and vegetables have been proposed to be associated with a greater degree of alkalinity. Thus, there is a need to determine the antioxidant capacities of selected vegetables with a particular focus on understanding how their pH influences antioxidant activity. This study evaluated 15 locally available vegetables: Fluted pumpkin leaves (Ugwu), Jute mallow (Ewedu), Bitter leaf, African basil (Scent leaf), Amaranthus, Cabbage, Lettuce, Okro, Cucumber, Cayenne pepper (Sombo), Habanero pepper (Rodo), Bell pepper (Tatase), Tomato, Carrot and Spring onions. The pH of the fresh and freeze-dried samples, Phytochemical analysis (Total phenolics and Ascorbic acid content) and Antioxidant Analysis-1, 1-diphenyl-2- picryl-hydrazil (DPPH) radical scavenging activity, Ferric reducing antioxidant power (FRAP) assay, Nitric Oxide (NO) scavenging activity and Total antioxidant activity (TAC)-were determined. Correlation analysis was done to establish relationships between pH, phytochemical constituents and antioxidant capacities of the selected vegetables. Results revealed that most of the fresh and freeze-dried vegetables had pH less than or greater than 7 respectively. The vegetables with higher concentrations of phytochemicals-ascorbic acid and total phenolic- had higher antioxidant capacities. While there was no significant correlation between pH and DPPH IC50 there was a significant negative correlation between pH of freeze-dried samples and NO IC50. Additionally, the pH of both fresh and freeze-dried vegetables was significantly negatively correlated with the TAC. This indicated that as the pH of the vegetables increased their antioxidant capacity reduced. Thus, the antioxidant potentials of these vegetables increased with increasing acidity which is contrary to popular belief
The Use and Perception of Online Learning among EFL Faculty Members in Yemen
Get PDFThis study examines the use, perception, and challenges of online learning among English as a Foreign Language (EFL) faculty members in Yemen. For data collection, a questionnaire was distributed to 50 EFL lecturers. The findings reveal significant variations in the use, perceptions, and challenges of online learning based on demographic factors such as age, gender, and academic rank. While faculty members frequently use online resources for professional development and encouraging student self-study, there is limited use of online platforms for formal assessments and regular coursework integration. Old-aged faculty members, males, and those with higher academic ranks generally demonstrated more positive perceptions of online learning effectiveness. However, female instructors and those with lower academic ranks reported facing greater challenges in implementation. Key challenges identified include technical issues, maintaining student engagement, and adapting traditional teaching methods to online platforms. These results highlight the need for targeted professional development programs, improved technological infrastructure, and tailored support systems that consider the diverse needs and experiences of EFL faculty in Yemen. The study contributes valuable insights for policymakers and educational leaders seeking to enhance the quality and effectiveness of online EFL instruction in Yemen’s higher education institutions, particularly in the context of ongoing conflict and limited resources
Wielding the Magic Wand: COIL integration in ASEP and WYM for Sustainable Global Education
Get PDFThis paper has examined the application of Collaborative Online International Learning (COIL) activities within Asian Student Exchange Program (ASEP) and World Youth Meeting (WYM). These programs offer a valuable framework for international university students to engage in cross-cultural collaboration centered on the United Nations' Sustainable Development Goals (SDGs) through topic-based competitions. This study analyzes how structured planning, guided facilitation, and intentional preparation within the COIL framework significantly enhance students' understanding of SDGs, while concurrently developing critical thinking, intercultural communication, and collaborative problem-solving skills. Moreover, this study is comprised of a qualitative investigation of the COIL projects. The goal of our research is to evaluate the perceived opportunities and challenges of COIL as a potential policy for internationalization, and its utilization within ASEP and WYM, grounded in educational contexts. To accomplish this aim, our research conducted interviews with 6 participants involved in the COIL programs. The paper applies thematic analysis to address the challenges encountered in both the online and onsite phases of these COIL experiences, offering insights for educators to foster COIL events more smoothly and efficiently
Understanding Summative and Formative Assessment Dynamics
Get PDF This paper aims to review the literature on types of assessment. Specifically, the paper seeks to define what is meant by summative assessment and formative assessment, and to clarify the differences between these two types of assessment. The paper also discusses the relationship between summative and formative assessment, arguing that although these types of assessment might seem to be different at many levels, their general goals should be the same. The present paper argues that effective language learning is better enhanced when both summative and formative assessment are used congruently. In this way, data that are gathered by means of formative assessments should be used to complement and consolidate data that are collected using summative assessment tasks. The paper, thus, suggests some strategies for balancing summative and formative assessments
A Review of Frameworks for Evaluating the Security Performance of E-Government Systems
Get PDFThe use of information and communication technology (ICT) is rapidly expanding throughout society. Different ICTs are used by governments to communicate with their country's citizens and other e-government initiative stakeholders. The e-government initiative faces various internal and external challenges, including limited funding, rapid technological advancements, internet accessibility for the public, and concerns about privacy and security. To address these challenges, several frameworks have been proposed that help improve E-government performance. In order to measure the effectiveness of e-government, this paper aims to identify various constructs and their relationships by providing a summary of the proposed frameworks and models for electronic government development
Mathematical Modeling and Analysis of the Spread of Varicella (Chickenpox) Disease with the Caputo Operator
Get PDFIn this study, we present a mathematical model for studying the dynamics of varicella disease transmission incorporating Caputo's fractional derivative to account for memory effects in disease spread. The aim of this research is to construct a robust mathematical framework that combines fractional calculus with disease modeling and explore fractional order parameters impacts on diseases propagations. Thus, the significant contribution to knowledge is the improved understanding of infectious diseases? dynamism as influenced by memory effects thus providing profound insights which can be used as cornerstones in developing preventive measures. The technique of this study relies on integration a system of differential equations which are subjected to the Caputo fractional operator. A variety of data sources were used, including existing epidemiological varicella literature for model calibration. We begin by analyzing the existences and uniqueness of the solutions to this model, utilizing the Banach Fixed-point theorem, the linear stability analysis of the model, using Lyapunov Functional approach. The analysis also includes key epidemiological parameters (: basic reproduction number) and dynamic response of the disease-free equilibrium. The effect of the fractional order parameter is investigated through numerical simulations performed by appropriate computational tools especially concerning an infection peak and asymptotic behavior. The results indicate that the varicella transmission dynamics are related to order parameter of fractional order . The results of this study demonstrated that to better describe epidemiological data, it is essential to introduce fractional order operators within infectious disease models able to represent nonlocal and complex phenomena
Yemeni EFL Learners' Typical Pronunciation Issues: Quantitative Analysis of Enhancement via Structured Interview-Based Intervention I
Get PDFAbstract
In English as a Foreign Language (EFL) classes, effective communication requires proper pronunciation. For reasons that include insufficient teacher training, outdated curricula, and lack of teaching materials, pronunciation is neglected in many Arabic-speaking countries such as Yemen. This quantitative research study evaluates the effectiveness of a structured interview-based intervention designed to resolve common pronunciation problems faced by Yemeni EFL learners. A total of thirty students from Hodeidah University in their eighth semester participated in a two-week workshop aimed at segmental (consonant clusters, vowel alternation) and suprasegmental (stress, intonation) teaching. Pre- and post-intervention interviews, using Munro and Derwing's (1995) taxonomy, noted significant reductions in three primary sources of error: stress misplacement (50% reduction), vowel substitution (46.43% reduction), and consonant cluster reduction (56.25% reduction). Most of the errors, particularly L1 interference errors, 56.9% and 27.4% intralingual transfer within a constrained context, contributed to the defined result.
This highlighted a particular contribution of an error source analysis, which somehow drew attention to the restructuring, or even more profound alterations, to how educational resources are allocated beyond the curriculum-focused changes limited to supervision, teacher training, and tacit behavioral guidance. By tackling an overlooked yet vital aspect of EFL teaching in Yemen, this study fills an important gap while offering adaptable, practical interventions for similar regions facing pedagogical and infrastructural challenges.
Keywords: accent modification, Yemeni learners of EFL, research interviews, error analysis, first language influence, phonological modification.
 
Evaluation of Infection Prevention and Control Practices among Healthcare Workers in Teaching Hospitals in Ibb City, Yemen
Get PDFIntroduction: Globally, nosocomial infections affect over 100 million patients each year. This study aimed to assess the perceptions, practices, and perceived barriers related to infection prevention and control (IPC) among healthcare workers (HCWs) in teaching hospitals in Ibb City, Yemen. Methods: A descriptive cross-sectional study was conducted among HCWs at teaching hospitals in Ibb Governorate, Yemen, from September 2024 to March 2025. Data were collected using a structured questionnaire. The selected hospitals followed infection control guidelines overseen by infection control committees. Results: Among the participants, 77% had attended seminars, and 71.3% had participated in IPC training courses. Although 67% were vaccinated against hepatitis B virus (HBV), only 65.7% had completed all three doses, and just 4.3% had received the COVID-19 vaccine. Overall, 74.6% demonstrated moderate perception of IPC, while 65.1% showed good IPC practices. A significant difference in IPC practices was observed between Al-Thawrah Teaching Hospital (77.6% good practice) and Jiblah University Hospital (52%) (p = 0.001). Significant differences were also found in perceived barriers between the two hospitals (p = 0.001). Furthermore, practice level was significantly associated with both knowledge (p = 0.001) and perceived barriers (p = 0.001). Conclusion: Despite good IPC knowledge among HCWs, gaps remain in their practical implementation. The strong associations between knowledge, practice, and barriers underscore the need for targeted training programs and sustained institutional support to strengthen IPC compliance in teaching hospitals