Search Marsden awards 2008–2017

Recipient(s): Dr P Du | PI | The University of Auckland
Dr LK Cheng | AI | The University of Auckland

Public Summary: Are you interested in finding out more about a previously unknown ‘rapid transition region’ in the stomach? This region is where the most vigorous contractions in the stomach begin to develop, accompanied by a drastic change in the bioelectrical activity of the stomach. I aim to employ innovative recording techniques and multi-scale mathematical models to bridge experimental observations and physiological processes of the stomach, from the cellular to tissue levels. The location of this rapid transition region will be demarcated experimentally using high-resolution electrical recording arrays and registering the arrays to subject-specific anatomical models. A mathematical model of the detailed tissue structures (e.g., fibre orientation), the cell physiology (e.g., bioelectrical activity), and the chemical messengers will be developed and incorporated into our model to present an integrative picture of the nature of the activities in the rapid transition region in the distal stomach. Through this process I will improve the state-of-the-art in this field and pave the way for an independent body of research to define the role of the rapid transition region in health and disease.

Recipient(s): Dr DL Hay | PI | The University of Auckland
Prof MA Brimble | AI | The University of Auckland
Prof TP Sakmar | AI | Rockefeller University
Dr HA Watkins | AI | The University of Auckland

Public Summary: Forty percent of medicines have cellular targets known as G protein-coupled receptors. With the right knowledge, many more of these receptors could provide society with new medicines. Many medicines mimic the actions of a natural hormone and have been developed from the chemical scaffold of that hormone. Larger “peptide” hormones have not been considered amenable to this approach because their “message” – or receptor activating component, has remained elusive. We have identified a possible message region for several important hormones, which we have named the 'activation motif'. We will create peptides containing only this message component and stabilise them using cutting-edge peptide chemistry techniques, leading to potent short fragments. We will also define in detail how one peptide binds to its receptor. Together, this will create a large body of knowledge about how peptide hormones can be exploited to combat disease.

Recipient(s): Dr AL Kohout | PI | NIWA - The National Institute of Water and Atmospheric Research Ltd
Dr R Gorman | AI | NIWA - The National Institute of Water and Atmospheric Research Ltd
Dr M Williams | AI | NIWA - The National Institute of Water and Atmospheric Research Ltd

Public Summary: Antarctic sea-ice is a key driver in the climate system. There is rising concern about the effects of increased storm activity in the Southern Ocean on Antarctic sea-ice extent. An increase in storms will lead to stronger winds and more powerful waves. Wave energy in a field of sea-ice can weaken the ice and break it into smaller floes. A sea of broken floes is more susceptible to dynamic and thermodynamic influences and has the potential to affect sea-ice extent. We hypothesize that increased storm activity in the Southern Ocean will increase wave presence in sea-ice. This hypothesis will be tested by incorporating an ice component into an operational wind-wave model. The model will be validated against Antarctic waves-in-ice observations. Our operational wave model will be used to simulate Southern Ocean storms and make predictions on the presence of waves in sea-ice. Our findings will be invaluable to the waves-in-ice community and will enable the investigation of the effects of increased wave presence on sea-ice extent through the application of floe break-up, dynamic and thermodynamic theory.

Recipient(s): Dr PK Olszewski | PI | University of Waikato
Prof JR Waas | AI | University of Waikato

Public Summary: As a society, we share resources even when they are extremely scarce. Remarkably, almost on a daily basis - in the family or in other social groups - we, just as other mammals, are willing to share one of the most crucial resources, food. Herein, we put forth the hypothesis that there are biological mechanisms facilitating this behaviour. We propose that oxytocin, a neurohormone whose roles include inducing social bond and promoting satiation, reduces appetite in order to propel the individual to commit the remarkable act of giving up food and sharing this resource with others.

Recipient(s): Dr NR Golledge | PI | Victoria University of Wellington
Dr CW Fogwill | AI | University of New South Wales
Dr DE Kowalewski | AI | University of Massachusetts, Amherst
Dr RH Levy | AI | GNS Science

Public Summary: The East Antarctic Ice Sheet (EAIS) constitutes the largest reservoir of fresh water on Earth, yet its potential contribution to future sea-level rise is not well constrained. Although present melt-rates are low, a better understanding of potential locations and rates of EAIS ice loss in coming centuries is essential. Interglacials of the early Pliocene (c. 4--4.5 Ma) are good analogues for future (warmer) scenarios, but geological records of sea-level changes from which former ice volumes can be inferred are equivocal, and cannot reliably establish whether the EAIS grew or shrank during these episodes. Using a sophisticated ice-sheet model, new continental topographic data, and climate simulations of early Pliocene conditions, we will simulate the evolution of the EAIS under a range of oceanic and atmospheric conditions. Our suite of experiments will establish the likely geometry of the early-Pliocene EAIS, from which we will gain a robust measure of its contribution to palaeo-sea levels. We will establish the rates and locations where greatest changes may occur, and identify whether thresholds exist. Setting our findings in the context of other warm periods of the geological past, we will gain a wider understanding of both past and future EAIS fluctuations.

Recipient(s): Assoc Prof JS Shima | PI | Victoria University of Wellington
Dr EG Noonburg | AI | Florida Atlantic University
Assoc Prof SE Swearer | AI | University of Melbourne

Public Summary: Many species produce excess offspring, and most individuals will die before they can reproduce. Such reproductive 'losers' may persist in populations for extended periods, to shape evolution and exact unknown costs on individuals that successfully breed (i.e., winners). The importance of 'survival of the fittest' is well recognised across biological disciplines, but what are the consequences of losers, which can compete for resources, attract predators, and alter the fates of winners? Since Darwin’s seminal work, existing paradigms have been preoccupied with winners; reproductive losers are rarely a focus of investigation. Our previous research on a small marine fish indicates that losers may be created when young individuals experience unfavourable conditions early in their developmental history. Our novel approaches have enabled us to unlock the 'environmental fingerprints' and demographic records preserved within fish ear bones, to conclude that: (i) young fish developing in offshore waters acquire distinct traits that transform them into losers; (ii) losers regularly colonise reefs alongside winners; and (iii) losers may be more readily shuffled between distant populations. We propose to integrate experiments, a longitudinal study, demographic reconstructions from ear bones, and mathematical modelling to reveal, for the first time, the hidden consequences of losers on winners.