This collection contains a series of papers dedicated in memory of Abdul-Aziz Yakubu, a colleague and friend to many within the mathematical biology community who passed away in August 2022 at the age of 64. Dr. Yakubu, who spent most of his career at the Department of Mathematics at Howard University, was known for his sustained stellar contributions to the development of theory and methodologies for formulating and analysing models arising in population biology, particularly the use and rigorous analysis of discrete-time models in ecology and epidemiology. The papers in this special JBD issue, contributed by collaborators of, and researchers whose work are related to, or inspired by, Dr. Yakubu's work, cover a wide variety of research areas in mathematical biology, particularly the use of discrete-time and continuous-time models to study real-life phenomena arising in population biology and ecology. Each article was reviewed by at least two independent reviewers, in accordance with the high-quality standards of the JBD. Main topics covered include discrete-time modelling of nutrients-phytoplankton-oysters system, discrete-time and structured modelling approach for host-parasitoid system, predator-prey systems, how heterogeneity in density-dependence affects disease spread, discrete-time models with delayed growth, formulation, analysis and simulations of models for SARS-CoV-2, and mycobacterium tuberculosis, a Darwinian model for the evolution of resistance in an SI model, modelling diabetic atherosclerosis, treatment of leishmaniasis with chemotherapy and vaccine, robust steady-states in ecosystems with symmetries, dynamical questions in volume transmission and Ehrlichia chaffeensis transmission dynamics in dogs.
The guest editors greatly acknowledge the support of the Editors of the JBD (Drs. James Cushing and Saber Elaydi) and the Production and Technical Team at Taylor and Francis, particularly Justin Robinson (the Portfolio Manager), for the great work throughout this process. We are thankful to the authors who contributed their excellent manuscripts and to the many anonymous reviewers for their constructive and diligent reviews.