Science by Email 20 January 2012

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	20 January 2012
News: Spot-on wasps By Tegan Dolstra Tiny microdots are being used to track the flight paths of wasps. Image: M. Whitehead Scientists are following wasps using a tiny tag originally used to track stolen cars. The circular plastic tags are called microdots. They are just half a millimetre wide, about the size of the full stop at the end of this sentence. Each microdot is labelled with a code, which can be read under a magnifying glass. Australian company DataDot Technology designed the dots to track stolen cars. Thieves often disguise cars, such as by changing their colour, so microdots can help identify a true owner. Now PhD student Michael Whitehead and his team from the Australian National University are using microdots to help them study the flight paths of wasps. Just like bees, some wasps help plants to reproduce by moving pollen between flowers. The scientists are studying a wasp species that carries the pollen of native Australian orchid flowers. The researchers collect the wasps by coating a pin with a smell called a pheromone that wasps are attracted to. Using nail polish, they attach a microdot to the back of each wasp. Because each microdot has a different code, it is like naming the wasps so they can be identified later. Using the microdots, Michael and his team found out how far the wasps can fly, and have tracked the flight path of individual wasps to see which orchid plants they visited. In the future, microdots could be used to tag elephant tusks and rhinoceros horns to stop them being taken illegally. More information Microdot technology for individual marking (video) Microdots spot on for wasp study Australian National Insect Collection Careers link Entomology: the scientific study of insects Find this story and more like it in the next issue of Scientriffic. Visit our website or call (02) 6276 6643 to receive this magazine as part of your membership to the Double Helix Science Club!
Try this: Store pumpkin seeds The most important things are a pumpkin and a colander.   Remove the seeds from the pumpkin and put them in the colander.   After washing the seeds, lay them out to dry on paper towels.   When your seeds have dried out, they are ready for storage.   You will need Pumpkin Water Knife Colander Paper towel Plate What to do Use a knife to cut open the pumpkin. Remove the seeds in the middle and place them in a colander. Under running water, pick the seeds out from any remaining pumpkin pulp and rinse the seeds well. Spread paper towel over the plate. Put the clean pumpkin seeds on the paper towel. Leave them to dry for a week in a warm, dry place. Once dry, store the seeds in a labelled paper envelope or small plastic bag. Keep them somewhere safe until you are ready to plant them. What’s happening? Drying seeds before storage prevents bacteria and mould from growing. But not all seeds survive the drying process. ‘Orthodox’ seeds can be almost completely dried and frozen, and will still be able to grow after storage. Pumpkins have orthodox seeds, as do eucalypts, acacias and sunflowers. Mangroves, on the other hand, have ‘recalcitrant’ seeds which are damaged by drying. Mango, avocado and other tropical fruit seeds are also sensitive to drying, plus they can be damaged by cold temperatures, making them particularly hard to store. Even some of your pumpkin seeds will be damaged by storage, so it’s worth saving three times more seed than you need. Bigger seeds are more likely to grow into strong plants, so use those seeds first. Applications An orthodox Judean date palm seed was accidentally stored for 2000 years. This long-lived seed sprouted in 2005 and has since grown into a tree. It is considered the oldest viable seed, though older ones might be waiting to be discovered. Seed conservation can help reintroduce lost or threatened species into habitats, so long as a seed from the species was collected and properly stored. Seed banks collect seed from many plant species, and research the best methods for storage for each variety. CSIRO’s Australian Tree Seed Centre (ATSC) has seed from over 1000 species of trees and shrubs. By Sarah Kellett Try another Science by Email activity on seeds More information Australian Tree Seed Centre Ancient palm resurrected from 2000-year-old seed Growing with science View the online version Quiz questions 1. What is the molecular formula for methane? 2. Which of these distances is the closest to the diameter of Earth? a) 2100 kilometres, b) 7600 kilometres, or c) 12 700 kilometres. 3. What is the name of the chemical that is responsible for wasabi's burning sensation? 4. Where would you find your fusiform gyrus? 5. What is Relenza? a) a type of bacterium, b) a drug for treating the flu, or c) a brand of robot used at mining sites. Did you know? The Australian synchrotron is a machine about the size of a football field that produces light around 1000 times brighter than the Sun. It is used to image and analyse a whole range of objects including living things, chemical compounds, rocks and artworks. Websites Watch it! “How and why does our brain construct faulty arguments? How do we use logic to ensure we can think critically about stuff and avoid our usual mental shortcuts to make decisions?” Find out in ‘The logic of critical thinking’, a series of short videos by TechNYou. It’s not always possible to take videos of phenomena scientists are trying to describe. Check out this talk by Drew Berry on the animations of unseeable biology. Events International: Google Science Fair 2012 Would you like to carry out a scientific investigation into a real-world problem? Then enter the Google Science Fair, an online science competition. Anybody from around the world aged between 13 and 18 can enter. All you need is an idea. Human movement, Sunday 22 January at 7.30 am on Network Ten Tune in for SCOPE’s ‘Japan Prize’ winning episode all about human movement! Look at the mechanics of the body, meet a Paralympian and find out how a magnet can move your muscles! Join Dr Rob as he puts one foot in front of the other and once again proves that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 26 January: Trains Sunday 29 January: Mammals Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. The molecular formula for methane is CH4. 2. The approximate diameter of Earth is c) 12 700 kilometres. 3. Allyl isothiocyanate is the chemical responsible for wasabi, horseradish and mustard's burning sensation. 4. You would find the fusiform gyrus in your brain. It is known to play a role in recognising faces. 5. b). Relenza is a drug for treating the flu. CSIRO researchers found a region on the flu virus that a drug can lock onto, stopping the infection from progressing. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editors: Jasmine Leong and Mike McRae | Manage your subscription | FAQ

 

 

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