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SURJ Edition 3 Science Undergraduate Research Journal at The University of Queensland Issue 3 | 2017 ISSN: 2204-2458 SURJ@UQ EDITION 3 2017 Welcome from the Editor I am delighted to present the third edition of SURJ@UQ. It has been a pleasure to work with our authors and I thank all of them for their involvement. Particular thanks goes to Zac Pross who has done a tremendous job with the authors’ pieces. This journal gives students at UQ and beyond the opportunity to communicate about science for the pleasure of writing, rather than for assessment! Here at SURJ we always enjoy seeing what students want to write about when they have free choice (rather than an assignment to complete), and I hope you enjoy reading their contributions. Susan Rowland (Editor in Chief, SURJ@UQ) All images used in this publication (other than the cover image) are distributed in their original forms with attribution. They are covered under Creative Commons Attribution-Non Commercial license. The cover image falls under Creative Commons Attribution-Non Commercial-Share Alike license; it has been modified with the addition of text. License details can be found here: https://creativecommons.org/licenses/by-nc-nd/2.0/ legalcode. The image in “The Future Seeker” is an original photograph by Aeryn Larkin. Contact details for each of our authors: Zac Pross https://au.linkedin.com/in/zac-pross-b8259359 Ainnatul Adawiyah https://my.linkedin.com/in/ainnatuladawiyyah Kurt Giuliani https://au.linkedin.com/in/kurtgiuliani Aeryn Larkin https://au.linkedin.com/in/aeryn-larkin-438bbbb6 Samantha Nixon https://au.linkedin.com/in/samantha-nixon-114280122 Kate Riggall https://au.linkedin.com/in/kate-riggall-85360359 Kimberley Stirk https://uk.linkedin.com/in/kimberley-stirk-3159aa81 Cover image: LH 95 stellar nursery in the Large Magellanic Cloud. NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration. SURJ@UQ EDITION 3 2017 ISSN: 2204-2458 Contents Title Page Interview with an Extra Terrestrial 4 Samantha Nixon The Future Seeker 9 Aeryn Larkin Superbugs and Mother Nature’s Solutions 10 Kimberley Stirk Interview with a PhD Student (or Two) 13 Kurt Giuliani The Study of Stress 17 Kate Riggall Blackleg Disease in Canola 19 Ainnatul Adawiyah Ahmad Termizi SURJ@UQ EDITION 3 2017 !3 Interview with an Extra Terrestrial The cosmic traveller I met in my backyard Samantha Nixon Sam completed a BBiomedSci (Hons) and is now pursuing a PhD at UQ. It's a late Sunday afternoon, and a casual stroll matched only by its indestructibility. There are through my backyard uncovers what could be over 1000 species and are found in almost any an alien life form. habitat on Earth. Terrestrial species are commonly found in soils, leaf litter, and mosses, It has eight stubby legs directly below a plump, while marine species make their homes in both segmented body. Attached to these legs are salt water and fresh water. bear-like claws that help it waddle across the greeny-brown expanse of mossy leaf-litter. On the inside, they seem much like us. They have muscles, a dorsal brain, and an alimentary Beneath my microscope, this family of tiny, canal digestive system; yet they are capable of translucent invertebrates seem perfectly surviving radiation levels hundreds of times content. Granted, they would be just as greater than a lethal dose to humans. They can comfortable at the bottom of the ocean or even hop between 150 ºC and almost absolute zero in outer space. with ease. Exposed to the vacuum of space? I have before me a population of water bears, No problem. No water or food for several years? each roughly half a millimetre in length (about Too easy. Subjected to several Mariana Trench’s the size of a period at the end of this sentence). worth of pressure? Still happy as a lark. The tardigrade ambles across all of these domains They are remarkable. as if saying “give me a challenge.” Also known as a tardigrade (of phylum This raises the question: how on earth (or Tardigrada), the water bear’s cuteness is indeed, elsewhere) do they do it? SURJ@UQ EDITION 3 2017 !4 Tardigrade. Credit: Phineas Jones https://www.flickr.com/ photos/phineasx/ leg – although there is debate whether this constitutes surviving. The tardigrade’s pervasive durability has attracted significant scientific attention. In 2008, the Tardigrades in Space (TARDIS) project took off – literally. The European Space Agency (ESA) A Never Say Die Attitude launched a number of tardigrades into orbit on the Russian FOTON-M3 mission The most resilient survival adaptations are with the aim of discovering whether the tough reserved for terrestrial water bears. Aquatic and little critters could survive the harshest marine environments are typically less environment of all: outer space. susceptible to damaging environmental factors such as ultra violet (UV) radiation and Four species were selected, all shown to temperature. Consequently, aquatic-dwelling possess extreme resilience to desiccation: water bears are significantly less hardy than Milinesium tardigradium, Richtersius coronifer, their land based cousins. Ramazzotius oberhaeuseri, and Echniscus tetsudo. They were dehydrated, packed on the Terrestrial water bears have been rocket, and sent into orbit. experimentally subjected to functional absolute zero environments (0.05 Kelvin or -272.95º Not only did they survive in the vacuum of Celsius) for as long as 20 minutes, and after space for ten days, they successfully being warmed and rehydrated were perfectly reproduced upon returning to Earth. Some healthy. Even storing water bears for two years tardigrades even endured the intense solar, at -200º Celsius didn’t disrupt them – nor did gamma and ionising radiation that comes with +150º Celsius. space exposure. And thus, along with bacteria and lichens, tardigrades are the first animal Extreme pressures of 40,000 kilopascals (nearly known to survive in space. 400 times greater than Earth’s atmospheric pressure) similarly did not affect egg-laying or Die, Wake up, Feed, Breed daily activities. Water bears can also survive The water bear’s trump card lies in its ability to extreme chemical stresses such as high shut down its own metabolic systems – a concentrations of carbon monoxide and process called cryptobiosis. Cryptobiosis refers dioxide. They have been shown to survive to a reversible state where metabolism is extreme dehydration for 10 years. After 120 suspended in response to an extreme years of dehydration, one tardigrade moved a environment. For all intents and purposes, the water bear appears dead – but it isn’t. SURJ@UQ EDITION 3 2017 !5 Terrestrial water bears are aquatic animals that surround themselves in a film of water, but live in terrestrial habitats. Mosses and lichens present a sponge-like, water-filled environment in which tardigrades love to bathe. However, mosses are susceptible to drying out, and the absence of liquid water presents a problem for the water bear. Enter anhydrobiosis. As the mosses dry out, so too do the water bears – losing a third of their size as Moss. Credit: Andrew Hill https:// they forfeit up to 97% of their water content. www.flickr.com/photos/47042618@N06/ Metabolism grinds to a halt as the tardigrade minimises its surface area by tucking its head In a tun, tardigrades can also live under and legs under its body. This impenetrable ball conditions of extreme cold. Cells are largely structure is called a tun. It’s a process filled with a liquid called cytoplasm, and the comparable to removing all moisture until just freezing of this liquid will cause a water bear’s the key ingredients remain – like the process of metabolism to stop. powdering milk. A tardigrade can reanimate out The problem is, cytoplasm is ~90% water, and of its tun form when water is made available. It since water expands when frozen, the process was in this tun form that the tardigrades of the of freezing cytoplasm should rupture the TARDIS program successfully returned from surrounding cell. Not so in tardigrades. The space unscathed. most likely explanation is that tardigrades are The tardigrade may enter anhydrobiotic states able to produce molecules (cryoprotectants) several times a year, and in these states they that alter the temperature at which cells freeze, can survive almost anything. But even in allowing for a slow and controlled entry into anhydrobiosis, tardigrades are surprisingly cryobiosis. Alternatively, the cyroprotectants sensitive to altered oxygen levels. Of course, may inhibit formation of ice crystals, allowing for the wily tardigrade has evolved a means to easier thawing. cope. Extreme salinity poses no threat to water bears Oxygen levels can diminish when a water either. Marine tardigrades can overcome bear’s mossy habitat is flooded with rain. In enormous osmotic gradients to maintain response, the tardigrade swells up like a Mr osmotic homeostasis. Others again rely on the Stay-Puft Marshmallow Man, floating on the trusty tun, which is impervious to osmotic water until the moss dries out. Life in the exchange. Furthermore, ultra violet radiation absence of oxygen is called anoxybiosis – usually harms DNA, yet tardigrades seem able another form of cryptobiosis. to repair the damaging effects of their sunburn. SURJ@UQ EDITION 3 2017 !6 Waterbears at Saguaro National Park. Credit: Katja Schulz https://www.flickr.com/photos/treegrow/ The exact molecular mechanisms that enable Perhaps options for their home planet lie in tardigrades to readily and sustainably undergo Epsilon Eridani, a solar system approximately so many forms of cryptobiosis remain a 10.5 light years away from our own. A mystery. Perhaps a greater mystery lies in why cryptobiotic tardigrade could conceivably these complex survivorship strategies have travel and survive on an asteroid from this evolved in just the one type of organism? faraway home…if its rocky vessel was traveling at close to the speed of light.
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