Science by Email 15 June 2012

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	15 June 2012
News: Teenager’s research aids stroke recovery By Patrick Mahony CT scan of a stroke patient's brain. The area outlined in red indicates the part of the brain damaged by the stroke. Teenager Jessica Garrett’s father suffered a severe stroke. A stroke occurs when oxygen flow to the brain is blocked, causing brain cells to be damaged. In Jessica’s father’s case the stroke was caused by a blood clot. The effects of a stroke can be severe. Consequences include paralysis, loss of speech and changes in personality. In severe cases, strokes may be fatal. Thankfully, Jessica’s father survived. The stroke damaged parts of his brain associated with movement. Some stroke patients can recover their abilities through rehabilitation. The rehabilitation process can be difficult – basic movements and tasks, such as walking, need to be learned by the brain all over again. During her father’s rehabilitation, Jessica made an observation: her father walked faster and with more confidence on plain carpet. When the carpet was multi-coloured, he had more difficulty. Jessica talked to physiotherapists and also researched scientific literature to discover why this might be the case, but wasn’t able to find an answer. Jessica hypothesised that more colourful and patterned carpets reduce the mobility of recovering stroke patients. She decided to test this hypothesis as part of a CSIRO CREST project. She worked with the rehabilitation centre and found that other stroke patients also walked more slowly on multi-coloured carpets. She also interviewed the patients, who confirmed that it was harder to walk on these carpets. Jessica concluded that the reason for this is because multi-coloured carpets create more visual input, which takes the brain longer to process. In a healthy brain, this isn’t a problem. Stroke patients are re-training their brains, so more visual input makes walking more difficult. Jessica’s work went on to win first prize in the Science Educators' Association of the ACT Science Fair, second place at the BHP Billiton Science Awards, and a third prize at the Intel International Science and Engineering Fair. Back home, the rehabilitation centre has changed its floor covering so that they are all plain, in order to aid the recovery of stroke patients. Jessica’s story shows how moving life experiences can raise questions that lead to scientific discovery. More information Stroke – the after effects CREST – Creativity in Science and Technology BHP Billiton Science Awards Science Educators' Association of the ACT Careers link Neuroscience
You will need these materials.   Use a blob of plasticine to make the ruler stand up.   Drop the ball from a height of 50 cm. How high does it bounce?   Place a thin layer of sand into the tray. Drop the ball again. How high does it bounce now?   Try this: Bounce!   You will need Tennis ball Long ruler Plasticine Table Tray Sand What to do Use a blob of plasticine to make the ruler stand up straight on the table. Drop the tennis ball from a height of 50 cm. Record how high the ball bounces. Repeat a few more times and find the average height that the ball bounces. Place the ruler so it stands up straight in the tray. Fill the tray with a thin layer of sand. Drop the ball from a height of 50 cm. Repeat the same number of times and find the average. Compare the two averages. Take the ball, ruler and plasticine outside and test a few more surfaces, such as cement and grass. What do you observe? What’s happening? When you lift the ball off the ground, you give it potential energy. This means the ball has potential to do work. When you release the ball, the potential energy is converted into kinetic (moving) energy. The ball collides with the surface and rebounds. As the ball moves up, it slows down – kinetic energy is being converted back into potential energy. You will observe that the ball doesn’t reach its original height. This is because the kinetic energy of the ball has been transformed into other forms of energy, including sound and heat. Energy also goes into deforming the ball during the collision. When the ball hits a hard surface, the surface doesn’t deform much. More energy is conserved in the ball, so it bounces higher. In the case of the sand, the surface is quite soft. The sand deforms significantly, meaning more energy is lost. As a result, the ball doesn’t bounce as high. Applications Tennis is played on a number of different surfaces, including grass, clay and hard courts. Tennis balls bounce differently on these surfaces. For example, clay tennis courts are considered ‘slow’ because the speed of the ball bouncing off these courts is slower, and the ball bounces higher. This makes the rallies, on average, longer. Grass courts are considered ‘fast’, because their slippery surface makes the ball skid and bounce low. Rallies on grass courts tend to be over faster, and favour players with a strong serve. The different surfaces and bounces of the ball mean that tennis players use different types of shots on different surfaces. A number of players also have a preferred surface that suits their favoured style of play. By Patrick Mahony Try another bouncing Science by Email More information Balls stick, shoes slide: serving up tennis court physics View the online version Quiz questions 1. What is the name of the force that keeps the Moon in orbit around the Earth? 2. What is the name given to waves caused by the disturbance of a large volume of water, often as a result of an earthquake? 3. What is the heaviest Australian bird? 4. What are the names of the elements that have atomic numbers of 114 and 116? 5. What tasty substance is produced by Apis mellifera? Did you know? Differences in the environment that laboratory mice are raised in can affect the results of experiments by influencing mice behaviour. Websites Do it! See the world through the eyes of a bee in this simulation! Watch it! Watch this video of the brightest light ever detected from the Sun. Last chance to win a Parkes Observatory online shop gift voucher! Take a photo of a stunning sunset or sunrise and email it to us along with your name, address and age. Two winners will receive a $100 gift voucher for the Parkes Observatory online shop. Entries close today, 15 June 2012. Full terms and conditions can be found here. Pet science, Saturday 16 June at 9.00 am on Network Ten Whether you're a dog person, a cat person, a bird lover or a reptile keeper there is a lot of science involving pets. Join Dr Rob as he knocks on the kennel door and SCOPEs out all the science behind our animal companions! Next episodes: Thursday 21 June, 4.00 pm: Animal superpowers Click here to have your own episodes of SCOPE to watch whenever you feel like it! Charges apply. Quiz answers 1. Gravity is the force that keeps the Moon in orbit around the Earth. 2. Waves caused by the disturbance of a large volume of water are known as tsunamis. 3. The heaviest Australian bird is the cassowary. 4. Element 114 is named flerovium and element 116 is names livermorium. 5. Apis mellifera, the honey bee, produces honey. Research from Monash University suggests that the reason flowers on opposite sides of the Earth evolved similar colours is due to bees. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Jasmine Leong| Manage your subscription | FAQ

 

 

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