Understanding IPM uptake using epidemiological and behavioural modelling

Supervisors: Dr Stephen Parnell, Dr Ed Hill

Reducing reliance on pesticides is an important global challenge. However, crop diseases cause up to 40% yield losses, and pesticide use continues to rise. Integrated Pest Management (IPM) is acknowledged as the solution, and the UK government has a scheme of incentives to encourage its adoption, but it is still perceived by many farmers as complicated and costly. By incorporating human decision-making behaviour into ODE models of crop disease, we can gain an insight into how best to apply these incentives. Understanding both the disease system and the behaviour of farmers is key to planning a successful transition away from pesticides, while continuing to manage diseases that threaten our agriculture.

Mathematical modelling of the finch trichomonosis outbreak in British greenfinches

Supervisors: Dr Erin Gorsich, Prof Matt Keeling

Trichomonosis (caused by the parasite Trichomonas gallinae) is a disease which has long been endemic to pigeons, finches, and many other species. Historically widespread mortality as a result of the disease was not seen in finches, but in 2005 an outbreak began in Britain which has resulted in severe declines in the national greenfinch populations.

These population declines, and observances of sick greenfinches, have been recorded in data sets which have been routinely collected by the British Trust for Orthithology (BTO) and the Institute of Zoology at the Zoological Society of London (IoZ). In my research, I am developing models to represent the dynamics of trichomonosis in British greenfinch populations, and fitting these models to the data.

(Image attribution: Egor Plenkin from Karelia, CC BY 2.0 via Wikimedia Commons)

Conference talks and seminars

BES Annual Meeting 2023 (15 December 2023) - Modelling the emergence of finch trichomonosis in the UK

SPAAM Seminar, University of Warwick (14 March 2024) - Modelling the emergence of finch trichomonosis in the UK

PiFORUM24 (3 September 2024) - Towards a Pesticide-Free World: Epidemiological and Behavioural Modelling

MSc group project: Using age data to improve targeted intervention campaigns against African sleeping sickness in Guinea

Supervisor: Prof Kat Rock

African sleeping sickness, or gHAT (gambianese human African trypanosomiasis), is a disease which is targetted by the WHO for elimination of transmission by 2030. Much progress has been made towards this goal, but in many countries, including Guinea, new cases continue to arise. An enduring issue reported by screening teams is the low participation rates of working-aged men, who are also believed to be at high risk of infection.

Recent data collection efforts in the most at-risk regions of Guinea mean that information is now available about the age and gender of individuals who have tested positive for gHAT. In this project we built on the work of the Warwick HAT MEPP group; modifying their existing model to account for age and gender demographics, and using the newly available data to suggest demographic-based strategies which may improve the current testing procedure, and speed up the path towards elimination.

MMath research project: Towards a mathematical model for blood hormone levels in transgender patients taking testosterone replacement therapy

Supervisor: Dr David Wood

Mathematical models can be used to simulate the behaviour of biological systems, with one common application being that of systems in the human body. These theoretical models allow us to simulate the impact of medications on internal systems, in order to better regulate the internal processes which medication seeks to control, and to better understand any side-effects which can be incurred. Models of the "male" and "female" endocrine systems have been in use for decades, including to explore the effects of HRT (hormone replacement therapy) in cisgender patients. But little research has been done into how HRT interacts with the endocrine system of transgender patients; that is, individuals with a traditionally "female" endocrine system who take testosterone, and vice versa. Much of the treatment currently in practice is effective, but there has been little theoretical study of results found in clinical practice, or attempts to analytically understand the internal system which is being regulated during treatment.

In this project I began constructing a mathematical model for the endocrine system of transmasculine patients taking testosterone replacement therapy. This used existing models of the "female" endocrine system, and attempts to adapt these models to include the interactions of testosterone, with a particular focus on the different outcomes when different treatment frequencies are applied.