Tuesday, 20 February 2018

Biosciences Seminar Speaker 22 February 2018

Biosciences Seminar Series - Winter 2018
22 February 2018 - 1pm - Zoology Museum


Ecological drivers and predictors of coral reef carbonate budgets

Dr Fraser Januchowski-Hartley

Photo by http://cola.zoom.nl/

Our Biosciences Seminar Series continues with a talk by Dr Fraser Januchowski-Hartley, from the Department of Marine Biodiversity, Exploitation and Conservation (MARBEC) at the University of Montepellier (France). Fraser is a marine biologist interested in the effects of traditional fishing and marine management on fish behaviour, and how changes in behaviour impinge on fishery and conservation goals, and more broadly in how local communities interact with coral reefs and on developing ways of co-management of marine protected areas. Fraser grew up in the UK and Malawi and his research has taken him to Fiji, Papua New Guinea, the Philippines, Vanuatu and the Seychelles. His project on investigating carbonate production and bioerosion on Kenyan coral reefs is part of the NERC funded Sustainable Poverty Alleviation from Coastal Ecosystem Services (SPACES) project - a transdisciplinary project aiming to fill critical knowledge gaps regarding how ecosystems contribute to wellbeing and poverty alleviation.


Abstract
Climate change is one of the greatest threats to the long-term maintenance of coral-dominated tropical ecosystems, and has received considerable attention over the past two decades. Coral bleaching and associated mortality events, which are predicted to become more frequent and intense, can alter the balance of different elements that are responsible for coral reef growth and maintenance. In particular, over the past 50 years there has been global decline in coral cover with associated shifts in the relative abundance of corals with different carbonate production potential. The geomorphic impacts of coral mass mortality and community change have received relatively little attention, particularly questions concerning temporal recovery of reef carbonate production and the factors that promote resilience of reef growth potential. 

To address this issue, my research focuses on how coral reef carbonate budgets can be estimated using underwater visual census of both carbonate producing (corals, crustose coralline algae) and eroding (parrotfishes, urchins, clionaid sponges etc.) guilds on coral reefs. First, I will present on how this method has been used to identify the different carbonate production potential of reefs in East Africa across a gradient of human influence, identify which aspects are of primary importance, and what this means for future vertical reef growth in the context of rising sea-levels. Second, I will demonstrate how these methods can be calibrated with widely used census methods at a local scale to estimate historical trends in carbonate budgets where this data exists, with examples from the Seychelles. 

We used data covering 20 years and at least one major bleaching event and the ReefBudget census method to identify that relatively high massive coral cover, and low macroalgal cover and abundance of excavating parrotfishes were essential in maintaining positive reef carbonate budgets. Further, we showed that reefs in the Seychelles were trapped into either positive or negative budget trajectories within a decade of bleaching, and that this was likely to persist after the 2016 bleaching event.




Hope to see many of you - everyone most welcome to attend!


For the list of forthcoming seminars see here

Thursday, 15 February 2018

BioMaths Colloquium - 16/02/2018

BioMaths Colloquium Series - 2017/18

16 February 2018 - 3pm Maths Seminar Room

(room 224 Talbot Building 2nd floor)


Mathematical analysis and simulation in ecology and evolution: A new model of isolation-by-distance that overcomes longstanding technical limitations

Dr Yevhen Suprunenko


(Institute of Integrative BiologyUniversity of Liverpool, UK) 



Our BioMaths Colloquium Series resumes for the winter term with a seminar by Dr Yevhen Suprunenko, from the Institute of Integrative Biology at University of Liverpool (UK). Yevhen started as a theoretical physicist and moved on to theoretical ecology, with the aim to use mathematical and physical methods to study the complex dynamics of living organisms - especially aspects concerning the role of spatially explicit dynamics, stochasticity, and temporal processes.


Abstract
In population genetics, models of isolation-by-distance (IBD) are crucial for understanding the role of evolutionary processes in the generation and maintenance of population genetic structure. However, despite the great importance and ubiquity of IBD in nature, a realistic mathematically tractable model is still missing due to the formidable technical difficulty of modelling nonlinear stochastic population dynamics. Instead, existing models of IBD use oversimplified and unrealistic approximations where spatial and/or temporal complexity is ignored, or only a limited number of evolutionary processes can be considered, e.g. selection and local density-dependent population regulation pose a long-standing problem. Here, we present a model of IBD which overcomes these technical limitations. The model takes into account explicit continuous spatial stochastic dynamics, selection, local density-dependent population regulation, limited spatial dispersal, genetic drift, mutation. We present approximate analytical solutions, asymptotically exact in a biologically relevant limit, for IBD patterns for neutral and non-neutral markers using arbitrary interaction kernels. Simulations show good agreement with our analytical predictions.


The discussions will continue over biscuits and tea/coffee after the seminar. 
Hope to see many of you!

For the list of forthcoming seminars, see here

Monday, 12 February 2018

Biosciences Seminar Speaker 15 February 2018

Biosciences Seminar Series - Winter 2018
15 February 2018 - 1pm - Zoology Museum


Tesla Valves and Turtle Lungs: The Loopy Evolution of Reptilian Respiratory System

Dr Colleen Farmer


Our Biosciences Seminar Series continues with a talk by Dr Colleen Farmer, from the Department of Zoology at Trinity College Dublin (Ireland). Colleen is broadly interested vertebrate evolution, especially concerning metabolism and vertebrate transitions. To do so she combines many laboratory and computational methods with cutting edge medical tools.


Abstract
The lungs of birds are extraordinary organs because they contain aerodynamic valves, and these valves cause air to move in the same direction through most of the conducting airways during both phases of ventilation. It has long been thought that birds are unique in this way, and that airflow is tidal in the lungs of other animals, but research from my lab has revealed that aerodynamic valves exist in the lungs of crocodilians, and at least some species of turtles and lizards.  We create computational fluid dynamic models, measure flow with several techniques, and visualize flow in order to make maps throughout the lungs, and to gain insight into the mechanistic basis of how these valves work. Our aim is to help shed light on the evolutionary history of the vertebrate lung..




Hope to see many of you - everyone most welcome to attend!


For the list of forthcoming seminars see here

Wednesday, 31 January 2018

Biosciences Seminar Speaker 01 February 2018

Biosciences Seminar Series - Winter 2018
01 February 2018 - 1pm - Wallace Lecture Theatre

Note Change of Room

The Genetics and Epigenetics of Parental Care

Dr Chris Cunningham


Our Biosciences Seminar Series resumes for the Winter term! And we are delighted to open it with a talk by Dr Chris Cunningham, who joined our Department of Biosciences last year as Lecturer in Behavioural Genetics and Social Neuroscience, coming from the University of Georgia in Athens (USA). Chris is broadly interested in understanding the molecular mechanisms and evolution of social behaviour, such as parental behaviour (e.g. see here; more about that in the seminar), but including also questions about the existence (or not) of anatomical specialization for male-male competition in hominins (see here and here).


Abstract
Behaviour, like any other phenotype, is traceable to how and when genes are expressed, with distinct gene expression profiles underpinning distinct behaviours. This is true even for short-term behaviours, such as shifts in aggression and mating. My laboratory interrogates the molecular mechanisms that initiate and maintain social behaviours. We use the burying beetle Nicrophorus vespilloides as a study species. This species has elaborate parental care, including the regurgitation of pre-digested food into the mouths of begging larvae. We use this species’ parental care to dissect the association of behaviour and social context with gene expression. Currently, we are most interested in epigenetic mechanisms and how they help initiate and regulate gene expression changes during behavioural transitions.




Hope to see many of you - everyone most welcome to attend!


For the list of forthcoming seminars see here

Thursday, 7 December 2017

BioMaths Colloquium - 08/12/2017

BioMaths Colloquium Series - 2017/18

08 December 2017 - 3pm Maths Seminar Room

(room 224 Talbot Building 2nd floor)


Information sensitivity functions to assess parameter information gain and identifiability of dynamical systems

Dr Sanjay Pant


(College of Engineering, Swansea UniversityUK) 


We conclude the BioMaths Colloquium Series for this Autumn term with a seminar by Dr Sanjay Pant, from the College of Engineering at Swansea University (UK). Sanjay's research ranges from cardiovascular modelling and medical device design and optimisation, to reduced order and probabilistic modelling, forward and inverse uncertainty propagation, surrogate modelling, information theory, and inverse problems.


Abstract
A new class of functions, called the 'Information sensitivity functions' (ISFs), which quantify the information gain about the parameters through the measurements/observables of a dynamical system are presented. These functions can be easily computed through classical sensitivity functions alone and are based on Bayesian and information-theoretic approaches. While marginal information gain is quantified by decrease in differential entropy, correlations between arbitrary sets of parameters are assessed through mutual information. For individual parameters these information gains are also presented as marginal posterior variances, and, to assess the effect of correlations, as conditional variances when other parameters are given. 

The easy to interpret ISFs can be used to a) identify time-intervals or regions in dynamical system behaviour where information about the parameters is concentrated; b) assess the effect of measurement noise on the information gain for the parameters; c) assess whether sufficient information in an experimental protocol (input, measurements, and their frequency) is available to identify the parameters; d) assess correlation in the posterior distribution of the parameters to identify the sets of parameters that are likely to be indistinguishable; and e) assess identifiability problems for particular sets of parameters. 

The application of ISFs is presented in three areas of mathematical biosciences: i) a Windkessel model, which is widely used a boundary condition in computational fluid dynamics simulations of haemodynamics; ii) the Hodgkin-Huxley model for a biological neuron, which has formed the basis for a variety of ionic models describing excitable tissues; and iii) a kinetics model for the Influenza A virus.



The discussions will continue over biscuits and tea/coffee after the seminar. 
Hope to see many of you!

Wednesday, 29 November 2017

Biosciences Seminar Speaker 30 November 2017

Biosciences Seminar Series - Autumn 2017
30 November 2017 - 1pm - Zoology Museum



Social structure and life-history evolution in resident killer whales

Dr Daniel Franks


University of York, UK

Photo by Dr Dan Franks


Abstract
Why females of some species cease ovulation before the end of their natural lifespan is a longstanding puzzle in life-history evolution. In humans, as well as some natural populations of cetaceans and insects, reproductive aging occurs much faster than somatic aging and females exhibit prolonged post-reproductive lifespans (PRLSs). Determining the mechanisms and functions that underpin PRLSs has proved a significant challenge. Here I bring together both classic and modern hypotheses proposed to explain PRLSs and life-history evolution and discuss their application with particular reference to our studies of killer whales. In doing so I highlight the need to consider multiple interacting explanations for the evolution of PRLSs and discuss the key role of social structure.



Hope to see many of you - everyone most welcome to attend!

Thursday, 23 November 2017

Biosciences Seminar Speaker 23 November 2017

Biosciences Seminar Series - Autumn 2017
23 November 2017 - 1pm - Zoology Museum



Marine megafaunal extinction

Dr Catalina Pimiento


Museum für Naturkunde - Berlin, Germany

from: www.sharkopedia.discovery.com


Abstract
Millions of years ago, an 18 meters shark (Megalodon) used to live in all oceans of the world. How did this shark achieve such a large size? When, how and why did it become extinct? In this seminar, I will be talking about the answers to these questions, which not only provide insights into the role of apex predators in Deep Time, but which lead us to uncover a previously unrecognized extinction event that not only affected Megalodon, but also the global marine megafauna. In contrast with the effects of the extinction of small organisms like invertebrates, this extinction event resulted in an important erosion of functional diversity, leaving communities highly vulnerable to future extinctions, like the one we are facing today. Our next step is therefore to assess the extent of the loss of functional diversity as a consequence of the current extinction crisis, which is particularly affecting large marine vertebrates. 

My work, however, is not only about research questions. Science education and public outreach are an important component of my agenda and I will be sharing those with you as well.




Hope to see many of you - everyone most welcome to attend!


For the list of forthcoming seminars see here