Eight finalists presented their doctoral studies to compete for the one of four Royal Society of Victoria prizes that foster and recognise excellence in Victoria’s early career scientists. Covering a range of categories: Biomedical & Health Sciences, Biological Sciences (non-human), Earth Sciences, and Physical Sciences, the audience were enthralled with the young scientists’ research.
Axel Newton, School of Biosciences, University of Melbourne
Convergent evolution occurs when animals that share similar environments or ways of life develop similar features, despite being distantly related. Axel is investigating how various physical traits that are shared between distant species are generated at the genetic level. His main focus is a comparison of the extinct thylacine, a marsupial, to canids, such as wolves. The two last shared a common ancestor 160 million years ago, but are both large predators that came to look so similar that they were sometimes mistaken for one another. While the thylacine is extinct, there are specimens around the world in museum collections that he can study to trace the development of the animal and visualise their morphology.
He compared the skulls of 113 different mammals, to definitively show that the thylacine skull is more similar in structure to those of canids than other marsupials. After investigating physical similarities, he compared the genomes of thylacines and wolves to other vertebrates, and found that there were common similarities between the regulatory regions of the thylacine and wolf genomes. These are sections of the genome that regulate when other genes are turned on and off. To date, he has approximately 300 candidate convergent regions, which are undergoing accelerated evolution to result in the two animals developing similar physical traits to suit their shared way of life.
In order to determine the roles of these genes, he added individual candidate thylacine genes into mouse embryos and monitored when the genes were being activated during embryo development. He found that these thylacine genes tended to be switched on during the facial development of the mouse, therefore being consistent with thylacine and canids have similar skull structure. This is the first time genes from a thylacine have been expressed in a living animal since its extinction, and this work also represents a significant advancement in determining how DNA drives differences in form.
Radhika De Silva, Department of Civil Engineering, Monash University
Global energy and material consumption are expected to rise in exponential proportions during the next few decades, generating huge demands for deep earth energy (oil/gas) recovery and mineral processing. Conventional mining uses 10% of all energy consumed in Australia and therefore other methods of mining have to be devised to meet our increasing demands for resources. SCDA (soundless chemical demolition agents) offers a more environmentally-friendly alternative that involves running a solution of calcium oxide over rocks to fragment them and recovering the oils and minerals within. The drawback of this technique, however, is that it becomes inert in the presence of water – a major hindrance given the levels of water beneath the earth.
Radhika has modified SCDA technology such that the calcium oxide becomes hydrophobic (water-resistant) and retains its fluidity in the presence of water. He also adds calcium chloride to accelerate the reaction, as the manipulation of calcium oxide to make it hydrophobic slows down its ability to fragment rock. He therefore proposes a method of injecting the solution into rock in multiple stages to fracture rock under high confining pressure in order to draw out minerals without having to excavate large quantities of rock (which would then go to waste), for a more sustainable method of mining.
Victoria Coyle, Centre for Advanced Materials and Industrial Chemistry, RMIT
For diabetics, blood glucose monitoring is a daily chore for survival – and diabetics often test their blood levels more than once per day. It is typically performed by piercing the skin to draw blood, from which blood glucose concentration can be measured. With a combination of materials science, electrochemistry, and nanotechnology, Victoria is devising a non-invasive blood glucose sensor that measures glucose levels in the sweat instead of blood.
She coats a plain titanium substrate with nickel balls and dusts them with gold nanoparticles – creating “nano Ferrero Rochers”. Both nickel and gold are independently important in the development of highly sensitive electrochemical glucose sensors – sensors that detect the chemical process of electrons being transferred between molecules. Nickel and gold can react with glucose to cause electron transfer, and this reaction can be used to detect glucose levels. The use of gold additionally reduces interference from physiological contaminants, ensuring that measurements are glucose-specific and not compounded by other sugars. Victoria tested the ability of nickel and gold to detect glucose levels and found that the combination of the two works best. She also tested the sensitivity, specificity, and reaction time of her nanoparticle sensor and found that it is comparable, if not better than other detectors. She therefore is on the way to developing a wearable glucose monitor for diabetes management, and it may also prove highly efficient for other chemical sensing applications.
Anindita Samsu, School of Earth, Atmosphere and Environment, Monash University
Fractures of different sizes and shapes are scattered across the Earth – whether they be surface ruptures caused by earthquakes that span several meters, or cracks in rocks that are only a few centimeters long. The Earth’s crust is divided into a mosaic pattern of tectonic plates that is constantly (albeit incrementally) moving and stretching, and the continents as we know them are merely a temporary arrangement of the Earth’s landmasses. Anindita is piecing the past and present together, reconstructing past movements of the Earth’s crust and past configurations of the tectonic plates.
As Australia drifts further away from Antarctica, the Earth’s crust is stretched and fractures form beneath (and on) the surface. It was previously assumed that the stretching direction was always perpendicular to fracture lines in the rocks of the Earth, however, modelling the Earth’s crust in a sandbox, Anindata disproved this theory in favour of another: if there is a line of weakness, no matter which direction force is applied, the break will occur along the line of weakness (much like a Kit-Kat will generally split along the middle). She is exploring the “ancestry” of fractures in the Earth’s crust. Fractures at the surface (cover fractures) tend to inherit the characteristics of older basement fractures deeper down in the crust, as the crust is weaker along these lines. Examining exposed basement and cover fractures in the Gippsland Basin, Anindata has aligned them and mapped the fractures created over the past 160 million years as Australia drifted northwards, and her knowledge can be applied to rift basins and fractures around the world.
Sonya Fiddes, School of Earth Sciences, University of Melbourne
We are conscious of the effect of climate change on coral reefs, especially with the damage of two mass coral bleaching events to the Great Barrier Reef in the past few years, however not many of us ask the question that Sonya is: what effect do corals have on climate?
Marine organisms, such as algae, corals, phytoplankton, and seaweed, produce dimethyl sulphide (DMS), forming the basis of the CLAW Hypothesis. This hypothesis proposes a negative feedback loop between ocean ecosystems and the Earth’s climate: that when phytoplankton are stressed due to heat leading to overgrowth, they release DMS, which becomes sulphur dioxide in the atmosphere as a precursor gas to aerosol formation. With a greater concentration of aerosols in the atmosphere, sunlight is physically blocked from reaching the Earth’s surface and clouds become more condensed to promote rainfall. This negative feedback loop thus cools oceans to reduce phytoplankton stress. Sonya is investigating whether this hypothesis holds true for corals, by simulating a world with coral reef-derived DMS and a world without, and comparing their climates over a 10-year period. Her work may reveal that if we lose the Great Barrier Reef and other coral systems, there may be further implications than we currently realise.
Hayley Cameron, Centre for Geometric Biology, Monash University
Across the animal kingdom, maternal care – the way mothers care for their young – is a continuum. From those mothers who lay eggs and disappear into the wild, to human mothers who care for their children for 18 years (and often much longer), it is clear that the initial maternal investment is important for all animals. It is established that larger offspring outcompete smaller offspring in terms of their growth, survival and reproduction. It therefore would seem plausible that any mother would have the largest offspring possible, however, due to the limited resources a mother may have at her disposal, there is a trade-off between size and number of children that she can have as any resources she has would have to be shared among siblings.
Hayley studies Bugula neritina, a sessile marine animal that appears similar to seaweed and coral, as a model of families to investigate sibling competition. She found that larger offspring tend to perform better than smaller offspring only in low sibling densities, and that with a greater number of siblings, it can often be the other way around. She also discovered that despite the number of siblings, the families with children of the most variable size tend to do best as a family, given that different-sized offspring help each other to perform better. Her work demonstrates that sibling interactions influence maternal provisioning of resources for their young, and sheds light into the eco-evolutionary dynamics of maternal investment and sibling relationships.
John-Paul Fuller-Jackson, Department of Physiology, Monash University
Weight-loss is not a physiologically easy process – not only because it involves dieting and exercise, but also because the body is programmed to maintain its weight. Individuals who lose a lot of weight quickly can struggle to keep it off. Animals have both white fat (the fat that we tend to associate with health, used for storage of energy) and brown fat, which mediates thermogenesis (generation of heat). Thermogenesis can be induced when we feel cold or when we eat food. The extent to which thermogenesis in brown fat occurs influences weight loss and metabolism as it is an active process (that burns calories without you trying), and weight loss can be thwarted when this process stops due to metabolic slowing.
While most obesity studies have been conducted in male mice, their brown fat thermogenesis isn’t physiological comparable to that of humans. To overcome this, John-Paul monitored obesity in sheep and humans. He found that the combination of dieting and exercising, but neither alone, reversed metabolic slowing, allowing sheep to lose weight. Monitoring both male and female humans, revealed differences between men and women in meal-induced thermogenesis, and fluctuations in brown fat heat-generation with the menstrual cycle, and that there are also heat-production fluctuations in women at different stages of their menstrual cycle. John-Paul is therefore is looking at developing personalised ways of controlling body weight that target thermogenesis, as most weight-loss treatments currently focus on limiting energy in (e.g. by quenching hunger) rather than increasing energy expenditure.
Aidan Kashyap, The Ritchie Centre and Hudson Institute of Medical Research
Lungs are the one organ of the human body that don’t have to function until birth, as a baby will receive its oxygen through the placenta until the cord is cut. When it is cut, babies with congenital diaphragmatic hernia (CDH) have poor lung function and struggle to breath. The condition is caused when the diaphragm is absent or abnormal, allowing organs such as the stomach, liver, and intestines to protrude into the chest cavity, restricting lung development and resulting in abnormal airways and vascular structures.
Aidan tested three methods to reduce the burden of disease in sheep:
- Foetal surgical intervention (FETO), which involves inserting a balloon into the airways to force growth and expansion of the lung. He found that this resulted in bigger lungs at birth and improved blood flow to the airways.
- Giving pregnant mothers a course of sildenafil (the drug contained in Viagra) to treat pulmonary arterial hypertension. This reduced blood pressure in the baby’s lungs and increased blood flow and gas exchange (despite still having smaller lungs).
- Delaying umbilical cord clamping until sufficient lung aeration of the newborn is achieved. This prevents the initial period of hypoxia that newborns with CDH usually experience, therefore protecting the brain from high blood flow (as a baby with hypoxia will generally have increased blood flow to the brain to compensate for a lack of oxygen).
Aidan’s studies will now be translated into humans to improve lung development and function of babies born with CDH.