Science by Email 16 December 2011

	Having trouble reading this? Try the online version | Manage your subscription
	16 December 2011
Recent research suggests that the humble rat is capable of empathic behaviour. News: Rats offer each other a helping hand By Patrick Mahony Empathy refers to the sharing of another’s feelings. Humans and some primates are capable of empathy, but it isn’t clear which other animals might express this ability. Research in the USA has shown that rats can display some empathic behaviour. This is the first time such behaviour has been observed in non-primates. The researchers placed pairs of rats in an enclosure. One rat was trapped inside a see-through container, while the other rat was free to wander around. The free rat could let the other one out if it worked out how to open the door to the container. Most of time, the free rats worked out how to open the door after a few days. Each time the experiment was repeated, the wandering rat set the trapped rat free fairly quickly. This doesn’t necessarily demonstrate empathy. The free rat may have just been curious and formed a habit of opening the door, or it may have just wanted to play with the other rat. The researchers tweaked the experiment so the container held either an interesting object, or was left empty. The rats only opened the cage when it contained another rat, demonstrating that it wasn’t curiosity or habit that motivated them to open it. They then set up the experiment so that the rats would not have any other contact afterwards. The wandering rat still set the trapped rat free, showing that the rats didn’t just want to play together. Even when the researchers put chocolate in one container and a rat in another, the trapped rat was freed first about half the time. When the container holding chocolate was opened first, the wandering rat still left some chocolate for its trapped mate to eat later. These experiments suggest that empathy might not be restricted to primates. It also shows that, for rats at least, helping out a friend makes them feel just as good as eating chocolate. More information Helping a cagemate in need The evolution of empathy Careers Careers in neurobiology
You will need these materials.   Half fill the jars with cream.   To one jar add a tablespoon of detergent. Label this jar 'cream + detergent' ad the other jar 'cream'.   Seal the jars and shake the jar labelled 'cream' vigorously.   Shake the jar until the cream separates into butter and buttermilk. Repeat for the jar labelled 'cream + detergent'.   Try this: Make your own butter You will need Cream Two screw-top jars Detergent Measuring spoon Marker What to do Take the cream out of the fridge and put it on the bench for about 30 to 60 mins to bring it to room temperature. Half fill both jars with cream. To one jar, add a tablespoon of detergent. Label this jar ‘cream + detergent’. Label the other jar ‘cream’. Seal the jars. Make sure they don’t leak! Shake the jar labelled ‘cream’ vigorously until the cream separates into a solid (butter) and liquid (buttermilk). This may take up to ten minutes. Repeat for the jar labelled ‘cream + detergent’. What’s different? What's happening? Cream is an emulsion; tiny drops of one type of liquid mixed in another type of liquid. Cream consists of little globules of fat mixed in water. Fat and water don’t normally mix. The molecules that make up fat have two ends – one end that sticks to water, and one end that hates water. When the two liquids mix, the fat molecules form globules, with their water-sticky ends facing out to form a ‘skin’.   Because these globules are so tiny and mixed evenly through the water, the cream doesn’t separate into different liquids. When you shake the cream, some of the globules slam together. The water-sticky skin is pushed aside, allowing tiny globules to join together. Eventually the lumps of fat get larger and larger until you have one large lump of butter and liquid buttermilk. Detergent is a surfactant, a chemical that lowers the surface tension of a liquid. Like fat, a detergent’s molecule has two ends. One mixes with the water, while the other part mixes with fat. The detergent acts like a bridge, keeping the water and the fat together. When the globules slam together, detergent stops the fat molecules from clumping together,  stopping the cream from separating. The detergent is an emulsifier, because it keeps the water and the fat as an emulsion. Applications If you read the ingredients list of many food products, you will often see an emulsifier listed as an ingredient. Foods that contain both water and oils often have emulsifiers added to stop them separating. Adding emulsifiers improves the quality and appearance of food and can help to prolong shelf life. Other products such as creams, cosmetics, pharmaceuticals and paints often have emulsifiers added to them to keep the mixture well-blended. Try another buttery Science by Email activity More information How emulsifiers work How to make butter out of cream and why it works By Patrick Mahony View online version Quiz questions 1. How many neutrons are there in a deuterium nucleus?            2. Where would you find mitochondria? 3. What is measured in watts? 4. What is food security? 5. What is an apex predator? Victorian Double Helix Survey Do you live in Victoria? Would you like a chance to win a voucher to the CSIRO Shop? All you need to do is give your parents some homework! We’d like to know what kind of events your parents would like to see offered by the Victorian Double Helix Science Club in 2012. Even if you have never attended our events we would appreciate your parent's feedback. Follow the link to take part in our 10 minute survey and enter to win! Did you know? According to research from the ARC Centre of Excellence in Coral Reef Studies, brightly coloured parrotfish play an important role in maintaining the health of coral reefs by removing weeds and sediment. Website Watch it! What do you think causes the phases of the moon? Watch this video to see if you’re correct. Do it! Could you fix the food in a kitchen slip-up? Take this quiz and find out. Structures, Saturday 17 December at 9.00 am on Network Ten Ever wondered how houses and high-rises are designed and built? From their shape, to the materials used to make them and even the way they are put together, there is a lot of science in, on and around structures! Join Dr Rob as he puts on his hard hat and SCOPES out all the science behind structures, once again proving that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 22 December: Animal reproduction Saturday 24 December: Elements 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. There is one neutron in a deuterium nucleus.    2. Mitochondria are found in the cells of eukaryotes, the domain of life that includes animals, plants and fungi. 3. Power, the rate of energy conversion, is measured in watts. 4. Food security exists when people have access to enough safe, nutritious food to lead a healthy life. 5. An apex predator is a predator with no predators of its own. Palaeontologists have discovered fossil eyes of Anomalocaris, an apex predator that lived 500 million years ago. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science By Email. Editor: Mike McRae | Manage your subscription | FAQ

 

 

---