To be added or removed from the mailing list, or for any other information, please contact the MaPSS organisers: Eric Hester, Alexander Kerschl, Nathan Duignan, and Giulian Wiggins. For earlier years of MaPSS seminars, click here.
Seminars in 2018, Semester 1
All seminars will be held at 5:00 pm on Mondays in Carslaw Room 535A.
Monday, March 5th
Zeaiter Zeaiter (Sydney University) — The Effect of Thermoregulation on Honey Bee Colony Health and Survival
In recent years honey bee colonies have been experiencing increased loss of hives. One cause of hive loss is colony collapse disorder (CCD). Colony collapse disorder is characterised by a previously healthy hive having few or no adult bees but with food and brood still present. This occurs over several weeks. It is not known if there is an exact cause of CCD but rather it is thought to be the accumulation of multiple stressors placed on a hive. One of theses stressors is the breakdown of thermoregulation inside the hive. The bee life cycle begins with eggs that hatch into larvae that become brood. The hive contains combs which are made up of multiple cells; these cells house the brood. Pupal cells are capped off by adult bees (and so are known as capped brood) and they undergo changes to develop into an adult bee. In order for these capped rood to develop correctly, physically and mentally, the temperature within the hive must be regulated by the hive bees to ensure optimal development of the capped brood. Variations in the temperature, caused by the breakdown of thermoregulation, lead to deformations in the adults that emerge from capped brood. This later leads to these bees becoming inefficient foragers which also have shorter life spans. We model the effect of thermoregulation on hive health using a system of DDEs which gives insights into how varying hive temperatures have an effect on the survival of the colony.
Monday, March 12th
Joel Gibson (Sydney University) — A Brief Introduction to Differential Forms
The language of differential forms was developed in order to do calculus on (oriented) manifolds, particularly in more than three dimensions, where a plane is no longer determined by a normal vector. In this talk, I will give an introduction to integration using differential forms, with many examples in three dimensions relating back to the usual curve, surface, and volume integrals. Using this language, the gradient, curl, and divergence operators are replaced by a single operator, and Stokes’, the divergence, and fundamental theorems of calculus are replaced by a single equation. Time permitting, I will mention de Rham’s theorem, relating the cohomology of a manifold to solutions of differential equations.
Monday, March 19th
Pantea Pooladvand (Sydney University) — Do T cells compete for antigen?
When a pathogen invasion begins, our bodies immune response is two-fold. First, the T cells will go through a rapid expansion phase, in order to fight off the intruders, followed by a contraction phase which subsequently contributes to immunological memory. It is difficult to assess the contribution of initial T cell numbers to the total T cell numbers at the peak of the response due to the widely differing views in recent publications. Does the initial number of T cells determine the peak or is the T cell response limited by the amount of antigen present? Inspired by new experimental results from our collaborators, we introduce a system of ODEs to investigate this problem by considering that T cells compete for limited amount of pathogen. We propose that this competition between T cells limits the peak of response and we compare the dynamics from this system to our collaborators’ data. To further explore this problem, we consider a published model based on the opposing view, that T cell replication is an inbuilt developmental program. Can this model also explain the experimental results or is competition a better explanation of this phenomenon?
Monday, March 26th
Monday, April 9th
Andrew Swan — TBA
Monday, April 16th
Monday, April 23rd
Monday, April 30th
Monday, May 7th
Monday, May 14th
Monday, May 21st
Monday, May 28th
Monday, June 4th