Cristy Burne


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Flossed in translation

Feeling fuzzy? Go brush! That sweater-mouth feeling is plaque, a layer of soft white gunk coating your teeth.

And don’t forget floss, especially since today is Flossing Day. (Happy Flossing Day everyone!) And guess what? You can even use the same piece of floss as last time.

Don’t believe me? Ask your dentist. I did, for CSIRO’s Double Helix magazine….

DOuble Helix dentisry.JPGFlossed in translation

If you look at unbrushed teeth using a microscope, you’ll see hungry colonies of bacteria munching sugary leftovers from between your teeth. These bacteria release acids that dissolve the protective enamel on the outside of your teeth, and cause cavities.

“Brushing your teeth removes these bacteria, so they can’t sit on the surface of your tooth for too long,” explains dentist Dr Peter Klages. “But if you’re snacking throughout the day, the bacteria have a constant supply of sugar to work with, so you’re increasing your decay rate.”

Peter says it’s fine to brush right after a sugary snack, like dried fruit or lollies, but wait half an hour before brushing after an acidic drink, like juice or soda. This gives your saliva a chance to neutralise the acids and protect your enamel.

And what about re-using floss? Well, you reuse your toothbrush all the time, so…

“There’s no harm in reusing floss, provided it’s still intact enough to clean between your teeth,” says dentist Dr Peter Klages. “Flossing once a day maintains healthy gums, and helps avoid decay where the brush can’t reach.”

Just add water

Lost in the jungle without a toothbrush? No excuse.

“It doesn’t matter what you use, as long as you’re cleaning thoroughly,” says Peter. “Some cultures use cloth, others use a stick that has been feathered at the end.”

It’s best to brush twice a day: after breakfast and before bed. Peter also recommends drinking water after a meal, to wash away food particles and acid.

Mouth party

Dark, warm, moist and stuffed with food, your mouth is home to more than 400 species of bacteria, but not all of them cause decay. The main culprit is Streptococcus mutans, a bacterium that combines with proteins in your saliva to grow into plaque.

The new drill

Has your dentist spotted signs of early decay? A University of Sydney study suggests early decay can actually be reversed, with up to 50 per cent of fillings avoided if you:

  1. Ask your dentist to coat the trouble spot with fluoride varnish
  2. Clean the spot super-well every time you brush
  3. Cut back on sugary snacks and drinks
  4. Visit your dentist regularly

Peter says a two-minute brush is the minimum: “Brushing faster isn’t going to clean any better…You have to take time to get into those all the nooks and crannies, to clean really well.”

 

 

 


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How do RFID microchips work?

Happy International Veterinary Medicine Day! My best friend is a vet, and she spends her days looking after our pets. One of the things she does is inject microchips, to help us identify and find lost pets.

In Australia today, most dogs and cats carry a tiny microchip – about the size of a grain of rice – under the skin between their shoulder blades. Your pet can’t feel its chip, but this mini device helps many furry friends to find their way home.

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Lost and found: family pet

Vets like my friend use a special needle to inject a microchip under your pet’s skin. This is quick and only stings for a second, much like a vaccination. Once injected, the chip stays with your pet for life.

Each chip is coded with a 15-digit identification (ID) number. This number is listed in a database, matched with your pet’s name, address and owner details.

Your pet’s microchip is passive, which means for the most part, it does nothing.

“Basically it’s a glass tube with a copper coil inside it. It has no battery or anything like that,” says Bruce Knight, of Micro Products Australia.

But if you lose your pet, or find a lost pet, a vet can scan its microchip to reveal its ID number.

“Just like scanning groceries at the supermarket,” says Bruce.

Radio frequency identification: Power up!

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To communicate your pet’s ID number, the chip needs a source of energy. Providing this energy is the job of a microchip scanner.

Microchip scanners broadcast a low frequency radio wave of 135 kHz, or 135,000 vibrations per second. This wave is invisible, a very slow version of the same radio waves you tune into when you listen to music on the radio.

“All pet microchips must operate on that frequency,” says Bruce. “No matter where you go in the world, they will have a scanner that can read your microchip.”

When this low frequency radio wave bumps into your pet’s microchip, it sends a tiny electrical current whirling around the chip’s copper coil. Like a key winds a clock, the current provides just enough energy to power the microchip.

Once powered, the microchip can emit its own unique radio wave. The scanner captures this radio wave and decodes it, displaying your pet’s ID on its screen. The scanner must be held close to the microchip, because the radio wave has so little energy.

This use of radio waves to send coded information through the air is called radio frequency identification (RFID).

Did you know? Some microchips include a thermometer: when you scan the chip, it sends back your pet’s temperature as well as their ID.

From libraries to polar bears

RFID chips are everywhere: they’re used by libraries to manage books, shops to prevent shoplifting, and farmers to track the farm their animals grew up on, and the vaccinations they’ve had. Researchers use RFID chips to track rhinos in Namibia and polar bears in the Arctic.

You’ll also find RFID used in automatic toll booths, car immobilisers, electronic passports, smart travel cards and contactless card payments.

I originally wrote this article for CSIRO’s Double Helix magazine. Happy International Veterinary Medicine Day!


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Happy International Sloth Day (zzzz)

How cool are sloths? It’s time to celebrate! On this International Sloth Day, let’s celebrate sleep! Sloths in the wild sleep around 10 hours a day. Two hours is enough for a fruit fly, but cats sleep need 15 hours a day, cows sleep just four hours, and humans?

Well…how long do you need to sleep?

Stages of sleep

When you’re asleep, your brain produces characteristic brain waves. We graph these brain waves by measuring electrical activity inside your head.

We know that humans sleep in repeating cycles, each around 90 minutes long. Each sleep cycle includes different types of sleep:

  • Transition: You are drifting between being asleep and awake. You can be easily woken.
  • Slow-wave sleep (SWS or non-REM): You are deeply asleep. Your eyes don’t move. Your body temperature drops.
  • Rapid Eye Movement (REM) sleep: You’re still asleep, but your eyes are darting around, your heart is pumping fast, your brain is working hard…

If you sleep for ten hours a night, you’ll spend around two hours in REM sleep. We think REM sleep helps you learn and create memories. Most dreams happen during this time.

Double Helix Counting sleep.JPGDragon dreams

Gilles Laurent studied the brain waves of Australian bearded dragons. He found their sleep also cycled through REM and non-REM sleep, but much faster than humans: one cycle every 80 seconds, around 350 times a night.

This shared pattern of REM and non-REM sleep means the way we sleep and form memories may have evolved more than 300 million years’ ago.

“It suggests that these features existed also in dinosaurs, which are the reptilian ancestors of birds,” Gilles says.

Does this mean lizards dream?

“It depends a lot on how one defines dreaming,” says Gilles. “If one defines dreaming simply as off-line replay of previous activity…then I’d venture to say that pet lizards do dream.”

Animalzzzz

All animals need to sleep, but there are different ways to catch zeds.

Some animals—like dolphins and ducks—sleep with only half their brain, so the other half can stay alert and awake.

Many large herbivores—like elephants, cows and horses—can sleep standing up, but must lie down for REM sleep.

Newborn kittens and puppies only have REM sleep, suggesting this type of sleep is important to early brain development. As they get older, they have less REM sleep.

The platypus enjoys more REM sleep than any other mammal. Platypus have been seen ‘swimming’ or munching imaginary food while they’re asleep.

Even insects sleep. Fire ant workers nap for about a minute, 250 times a day; their fire ant queens sleep for six minutes, 90 times a day.

Sleep your way to success

Getting enough sleep is linked to improved creativity, concentration and memory, even in animals. Tired fruit flies, for example, make more mistakes and struggle to remember important things.

Sleeping can also help animals make healthier choices. Mice who don’t get enough REM sleep are more likely to eat fatty and sugary foods.

Are you human? Aged 6–12 years? Aim for 9–12 hours of sleep every day.

Help! My hamster’s dead!

Limp and floppy? Don’t panic. Your beloved pet may simply be hibernating.

Hibernating animals seem to ‘sleep’ away the winter, but we can tell from their brain waves that they’re still awake. When an animal ‘wakes’ from hibernation, it hasn’t actually slept, so it needs lots of proper naps to recover. Squirrels, frogs, mice, bats and even hamsters hibernate.

This article originally appeared in CSIRO’s Double Helix magazine.


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Going batty on International Bat Day

Ever seen 10 million bats? Would you like to? How amazing would it be to see the fruit bat migration in Zambia’s Kasanka National Park?!!?

Five to ten million straw-coloured fruit bats migrate every year through Zambia’s Kasanka National Park.

When the bats feast on fruits in the national park’s swamp forest, they’re hard to miss.

But after they leave, they can fly on journeys of thousands of kilometres. Tracking them has never been easier, thanks to GPS.

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Dr Martin Wikelski, director of the Max Planck Institute for Ornithology, tags the bats with mini high-resolution global positioning systems (GPS).

“The [tracking] devices can be downloaded from afar,” Martin says. “Also, they record 3D-acceleration, so we can reconstruct the behaviour of the bats while on the move.”

We can use this tracking data to answer many batty questions: How do bats interact with humans and wildlife? What foods do they eat? How do bats help the environment with services like spreading seeds?

We can also combine this bat data with data from other tracked species and from environmental sensors to help understand what’s happening in the broader ecosystem.chris-meyer-kasanka-bats-2.jpg

A version of this article first appeared in CSIRO’s Double Helix magazine… Bats do give me a bit of the creeps, but I also think they’re beautiful. Anyone keen to head to Zambia for the next migration? Happy International Bat Day!


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Celebrating sawfish on Shark Awareness Day

Did you know sawfish are related to sharks?

When I took on this story for CSIRO’s Double Helix magazine I didn’t know much about sawfish at all.

Now I know they’re a type of ray. I know they use their saws to detect the heartbeats of their prey, and also to stun fish and defend against predators. And I know they used to live around the world, but are now endangered. How cool is it to be a science writer and learn all these things as part of my job!!!

Double Helix Sawfish.JPGFishing up a huge surprise

It started out as just another fishing trip.

Lisa Smiler was using a handline in Wattie Creek, 900 kilometres south-west of Darwin, in the Northern Territory, when she felt that unmistakeable feeling: a bite on the end of her line!

“I thought it was a barramundi, or a catfish, or something,” Lisa says. Whatever it was, it was big.

“I was pulling the line, then my sister helped pull the line, and her partner pulled the line, all the way up to the edge of the river,” Lisa describes. “All of a sudden, my sister pulled up the nose part, and I said, ‘Oh no, I don’t want this fish, it’s freaky.’”

At 2.7 metres long, the fish weighed more than Lisa did. When she posted its picture on social media, Lisa set the scientific world alight.

Record-breaking fish?

According to Western science, Lisa’s sawfish is the first ever observed swimming so far inland—nearly 500 kilometres from the ocean!

But Indigenous knowledge says differently. Local rock art of a sawfish, or kunpulu, suggests Lisa’s ancestors had seen the fish already.

Ursula Chubb, a Gurindji ranger, monitors the rock art site. “When we go out on country trips with Elders, they talk about it, and I listen to them telling us stories,” she says. “It’s a very important fish from long ago, when our ancestors were living in this country.”

Lisa says she never dreamed she’d see a live kunpulu. “I’d just heard about the sawfish in the rock painting … I wasn’t thinking I would catch one.”

Tracking language

Kunpulu’ means ‘sawfish’ in Gurindji, and in other Indigenous languages too, even those spoken hundreds of kilometres from Gurindji country.

Dr Felicity Meakins has studied Indigenous languages for over 20 years. She says different words tell their own stories, and she uses these stories to learn about changes over time.

“You can use different languages to trace the path of the fish,” says Felicity.

“I would guess at some point this fish has appeared, and people have said, ‘This is a stranger in our country. What’s this?’ And they’ve asked more northern people…and that’s how that word kunpulu has been passed along.”

Solving the mystery

We don’t know when Gurindji people first saw sawfish, but with ochre samples from the rock art, we hope to be able to solve the mystery. Scientists have also taken DNA samples from Lisa’s sawfish, to help work out how many sawfish are in the river.

“We’re using Indigenous ecological knowledge and western knowledge to build up a picture of what’s happened with the sawfish,” Felicity says.

Endangered wonders

Sawfish once lived around the world but are now endangered. Baby sawfish are born in the ocean, at the mouth of rivers like the Northern Territory’s Victoria River or Western Australia’s Fitzroy River.

The pups swim upstream, spending years growing in the river before swimming out to the ocean. Adults can reach up to seven metres long.

 

My article was first published in CSIRO’s Double Helix magazine.


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How to tickle a rat: serious news on International Joke Day

giggling rats Helix.JPGIt’s International Joke Day, but let’s get serious. Evidence suggests a good laugh is great for our health. But what if you just don’t feel funny? Can tickling help?

That’s where research comes in. Dr Shimpei Ishiyama is studying tickling and laughter in rats. It turns out, anyone can learn to tickle a rat, he says.

“It is very easy…though there are some techniques, such as flipping them and tickling the belly, which you may need to practice a bit.”

Shimpei is studying the way rats’ brains react to a good tickling. He hopes to learn more about how our own brains work.

“Our results suggest that ticklishness has been conserved through evolution, and is related to playfulness. We speculate ticklishness is perhaps a brain’s trick to make us play with others, and have fun,” he says.

Ready, set, tickle

Shimpei and his team of ticklers have even noticed differences in rat personalities. Shy rats tend to laugh less, while playful rats laugh more.

Shimpei loved being tickled as a kid, but now he hates it. “It is also the same for rats. Young rats enjoy being tickled, while adult rats are annoyed,” he says.

meme-ratTop tickler’s tip:

Before you attempt to tickle your rat, take a deep breath. It’s important that you’re feeling relaxed and friendly.

“Rats…can sense the stress hormone in sweat on my palm, which could potentially make them nervous,” says Shimpei.

Is your rat missing its sense of humour?

Worried that your rats are too serious? Don’t worry. It’s normal to feel this way. And it could be your rats are having a super time, you just don’t realise.

Rats laugh at ultrasonic frequencies, so the human ear cannot hear their giggles.

I originally wrote this article for CSIRO’s Double Helix magazine 🙂 


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How to spot (and help) platypuses 

DSC_0020I’m lucky enough to be heading to the Whitsundays Voices Festival a couple of weeks early. Why? For some sun and beaches, but also some forests and hiking…

I’m also hoping to see a small, furry critter I’ve adored from afar but never actually laid eyes on:

The platypus.

On a scale of one to weird…

On a scale of one to weird, platypuses score super-high. They’re venomous, lay eggs, make milk, breathe air and live in fresh water. How cool is that!?!?!

“It doesn’t get much weirder,” says Josh Griffiths, a senior ecologist with 10+ years’ experience working with platypuses.

“They’re the most unusual creature on the planet. There’s still so much we don’t know about them, so any time I go out or do research, I’m going to see something new.”

DSC_0306.jpgWhat do we already know about platypuses?

Well, we know platypuses are amazing.

Bill: Their super-sensitive bill can detect underwater electrical pulses made by tasty beetles, insect larvae and yabbies. This means platypuses hunt with their eyes, ears and nostrils closed.

Limbs: Their short limbs are webbed (great for paddling) and clawed (great for digging).

Spur: Males have venomous spurs on their ankles. “The venom causes excruciating pain and massive swelling in humans,” says Josh. Platypus venom is so odd, we’re hoping it can be used to treat diabetes.

Coat: Their thick waterproof fur is perfect for staying warm and dry.

Tail: Flat and wide like a paddle, their tail is great for swimming. It’s also filled with fat, for energy reserves.

Size:  1–3 kilograms. “Like a small rabbit,” says Josh, “but they’re a very strange shape, because they’re long and streamlined.” Think 40–50 cm from tip of tail to tip of bill.

Eggs: The female lays her eggs in a 25-30-metre-long burrow that she’s dug into the riverbank. “It’s quite an effort for a one-kilogram animal,” says Josh. “The eggs around about the size of a 5-cent piece when they’re laid.” After just ten days, the eggs hatch.

Jellybean babies: “When platypus hatch, they’re the size of a little pink jellybean,” says Josh. “They’re basically a mouth, with not much else. Mum stays with them almost constantly for the first few weeks.” During this time, she feeds her bean babies with milk.

Milk: A CSIRO team led by Janet Newman has found a curly protein in platypus milk is great at killing bacteria. “Platypus are such weird animals that it would make sense for them to have weird biochemistry,” says Janet.

Where to see platypuses

Platypuses live across eastern and southern Australia. They’re mostly nocturnal, live alone, and are super-shy. “We don’t see them easily, so we don’t know whether they’re disappearing or not,” says Josh.

However, fingers crossed, they’re relatively easy to spot in the Eungella National Park, which is where I’ll be heading before the Whitsundays Voices Festival. Wish me luck!

Join the platypus party

Next time you go platypus-spotting, be a citizen scientist and record your success (or failure) on platypusSPOT.

“You can see where other people have seen platypus and try your luck in those hot spots,” says Josh. Even better, your information helps us learn more about where platypus live.

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Platypus can drown in yabby traps

What you can do to help platypuses today

There are two big ways we can all help platypuses:

  • Save water. “Every time we take a shower or turn on the tap, we’re using water from a platypus’ home,” says Josh.
  • Pick up litter: “It’s easy for a platypus to get tangled rubber bands or hair ties or bits of string,” says Josh. Platypuses also drown in yabby traps.

Injured platypus? Who you gunna call?

If you find an injured or sick platypus, don’t pick it up. “You could get put in hospital for your trouble,” says Josh. Platypus venom isn’t fun! Instead, call your local wildlife rescue operation.

Did you know?

Platypuses are one of only five living species of egg-laying mammals, called monotremes. The other four are all echidna species. Monotremes only live in Australia and New Guinea.

This post is adapted from an article written by me that first appeared in CSIRO’s Double Helix magazine. (c) CSIRO