Friday 24 December 2010

Ep 139: Christmas special - Santa, sport and out-takes

It's scarcely believable that another Christmas has rolled around! I hope that 2010 has been a wonderful year for you.

In this year's Christmas podcast, I've compiled some of my favourite segments from the last few years. First up, I chat to Bianca Nogrady, who assembled a crack team of health experts to look into the health of Santa Claus. Not only does he eat copious amounts of sugar and drink gallons of beer, he is also at risk of altitude sickness, deep-vein thrombosis, jet-lag, zoonotic diseases from exposure to wild reindeer and countless other problems associated with lack of sleep and poor diet. Not to mention all the concerns associated with smoking. However, he does compile the naughty/nice list each year, keeping his mind active, and unlike many other elderly folk, he gets out of the house and travels. You can read more about the findings of the Santa-team in Bianca's original article Health alert for Christmas visitor, and also at Ep 98: Santa Claus - a fat, diabetic substance abuser?

Next up is a classic out-take from Diffusion Science Radio from the velvet-voiced Matt Clarke discussing the fact that some women are allergic to their partner's semen. You will also hear the laughing of myself, Darren Osborne, Lachlan Whatmore and Tilly Boleyn (and possibly Ian Woolf). These same folk then join me in an interesting, and irreverent, take on some of the mental aspects of cricket. These recordings were originally released in the episode North Koreans, Mammoths, Invisibility and what did not make it to air on the Diffusion Radio Science Show.

Take care this break, and see you in the new year, when my family will have expanded by one!

Click play below or listen to this show here, and have yourself a merry Christmas!

Saturday 11 December 2010

Ep 138: The health benefits of breakfast

A world first study conducted by Menzies Research Institute Tasmania has shown that skipping breakfast over a long period of time may increase your risk of heart disease and diabetes.

The study, Skipping breakfast: longitudinal associations with cardiometabolic risk factors in the Childhood Determinants of Adult Health Study, published in the American Journal of Clinical Nutrition, followed up a 1985 national sample of 9–15 year old Australian children. The original work looked at whether these children ate breakfast before school. In 2004–2006, the authors of the new research tracked down 2184 participants of the original study (26–36 years of age) and enquired into their breakfast eating habits. This style of study is called a Longitudinal Study.

After adjustment for age, sex, and sociodemographic and lifestyle factors, participants who skipped breakfast in both childhood and adulthood had a larger waist circumference, higher fasting insulin, and higher total cholesterol concentration than did those who ate breakfast at both time points. The researchers conclude that skipping breakfast over a long period may have detrimental effects on cardiometabolic health.

I had a great chat to lead researcher Kylie Smith about her study. Listen in to this show here (or press play below):

Songs in the podcast:
I Love ManciniHarry Allen
"Breakfast At Tiffany's"

from "I Love Mancini"
My Many MoodsAmy Stephens Group
"Breakfast In Atlanta"

from "My Many Moods"

Smith KJ, Gall SL, McNaughton SA, Blizzard L, Dwyer T, & Venn AJ (2010). Skipping breakfast: longitudinal associations with cardiometabolic risk factors in the Childhood Determinants of Adult Health Study. The American journal of clinical nutrition, 92 (6), 1316-25 PMID: 20926520

Wednesday 1 December 2010

2D / 3D / 4D Baby Ultrasounds

Being able to see your unborn child is truly an amazing experience. Ultrasound (diagnostic sonography) is a common diagnostic tool for, among other things, imaging the foetus to determine its age, look for abnormalities and observe blood flow in the umbilical cord. But possibly its most memorable effect is seeing your baby's heart beat - and in 3D/4D ultrasounds, seeing your baby's face.

The term "ultrasound" applies to acoustic energy (sound) with a frequency above the audible range of human hearing (20 Hz -20 kHz). When used in medical imaging, an ultrasonic sensor (or transducer) is placed on the mother's belly and produces pulses of sound. The frequencies used for medical imaging are generally in the range of 1 to 18 MHz. High frequencies (7-18 MHz) can be used to look for fine details but have low penetration, so to image deep tissue, lower frequencies (1-6 MHz) are used.

The sound waves are partially reflected from layers between different tissues inside the mother's body. Sound is reflected anywhere there are density changes - for example, at the baby's skin where it meets the amniotic fluid. The baby's internal organs can also be imaged depending on what frequencies you use. The reflected sound is then "heard" by the transducer, and the data analysed to produce the image. The amount of time it takes for the echo to rebound relates to how deep the sound penetrated, and the strength of the return signal relates to both the material it is reflecting off and its depth. The deeper the tissue from which the signal is being echoed, the quieter the return, simply because there is more sound loss (attenuation) the further the sound travels (it gets absorbed, scattered and reflected along the way). This information allows an image to be built up, whereby pixels at the appropriate depth are coloured by the strength of the return at that point. Generally, the sound waves are not 100% reflected at any stage - you can see "behind" objects because some sound penetrates through. However, as less sound is penetrating the deeper you go, the signals become fainter.

2D Ultrasounds

Baby face 2D scan

The typical ultrasound image is a "2D" image like the one above. In this image, the transducer is at the top and is sending sound waves down. The image is essentially a slice through the mother. It's called a 2D image as we can only see two dimensions - left/right and up/down. The 2D image is built by firing a sound beam down, waiting for the return echoes, and then firing a new pulse at a slightly different angle. This continues until an arc is swept. Combining the data from each line after the arc is swept gives the 2D image. The following images come from the excellent resource Basic ultrasound, echocardiography and Doppler for clinicians, by Asbjorn Støylen. The left image shows the transducer scanning whilst the right image shows how the pulses are sent down in lines.

Continual rescanning means that a 2D video can be produced with roughly 50 frames per second. The human eye can see about 25 frames per second and so the video looks smooth. This frame rate is also more than enough for 2D temporal visualisation of the baby's heartbeat (~70-150 beats per minute depending on age) and to watch blood flow through Doppler ultrasound. Due to the Doppler effect, the sound pulse will rebound with a higher frequency if it hits something moving towards it, and a lower frequency if it echoes from something moving away from it - this is the same reason the noise of a car has a high pitch when moving towards you, and a low pitch as it moves away. As blood is moving in the umbilical cord, the ultrasound can be coloured by the Doppler information to show the blood flow.

3D Ultrasounds

Baby face

3D images are a fairly recent advance in diagnostic sonography. Instead of just seeing a slice through the mother, the images can show a surface - essentially adding depth (the third dimension) to the 2D image. Imagine you are looking at a car from front on - you have no idea how long the car is and you have no information on how many doors it has or if the boot is open. However, if you look at the car from another angle, you can figure this out, and the more angles you look down, the more depth information you can gain. This is essentially what a 3D ultrasound does - it stitches together multiple 2D shots from different angles to produce the image. Modern transducers have the ability to scan multiple cross-sections. If the baby is moving, there may be some blur, but as image processing is becoming quicker, the 3D images are becoming clearer. The colour of the image is not real as there is no way to see colour inside the mother. 3D scans provide information for the diagnosis of facial anomalies, evaluation of neural tube defects, and skeletal malformations, and also helps the parents bond with their unborn child (it's very cool). However, when compared to 2D scans, they aren't as useful for the diagnosis of congenital heart disease and central nervous system anomalies. One of the reasons why this is the case is because they are static, which leads us to...

4D Ultrasounds

The term 4D refers to the addition of time to 3D scans. This is a very recent advance as it is only in the last few years that we have had the computing power to not only stitch together the 2D images to make the 3D images, but to create the 3D images quickly enough to play them consecutively as a video. Modern 4D scans play at roughly 12 frames per second, so they are a little jumpy.

Here is a little video I put together of our 4D scan.

I don't know if there is an upper bound on what ultrasound technology can do - as the speed of sound is ~1540 m/s in human soft tissue, and you have no choice but to wait for the return signal before you can process the image, it may be that a high video frame rate with decent resolution is unobtainable. Resolution depends on how many different lines you fire down to make the first 2D image - more lines mean better resolution, but currently you have to wait for the echo from one line before sending down the next, which means it takes longer to produce an image. I imagine one way of improving this would be to send down all the lines at once with slightly different frequencies or waveforms, and as such when the echo is received you would know where it came from. Perhaps this is already being done - let me know if you know more!

Check out the video of Massive Attack's Teardrop in which there is a singing foetus, and I also have more images over at my ultrasound set on flickr.

  • Kurjak, A., Miskovic, B., Andonotopo, W., Stanojevic, M., Azumendi, G., & Vrcic, H. (2007). How useful is 3D and 4D ultrasound in perinatal medicine? Journal of Perinatal Medicine, 35 (1), 10-27 DOI: 10.1515/JPM.2007.002 
  • Carrera, J.M. (2006). Donald School Atlas of Clin. Application of Ultrasound in Obs/ Gyn DOI: 10.5005/jp/books/10226
  • Khanem, N. (2007). Donald School Textbook of Ultrasound in Obstetrics & Gynecology The Obstetrician & Gynaecologist, 9 (2), 140-140 DOI: 10.1576/toag. 

Wednesday 24 November 2010

Ep 137: Can your environment change your DNA?

Did you know that worker bees and queen bees have exactly the same DNA?

Although they look and behave differently, at birth they have the same genome. Young queen larvae are fed a diet of Royal Jelly, a substance secreted by the worker bees which includes B-complex vitamins, proteins, sugars and fatty acids. It also contains trace minerals, enzymes, antibacterial and antibiotic components, and vitamin C. This concoction not only feeds the queen bees, it turns on and off various genes with what are known as epigenetic effects. Epigenetic effects - meaning "above the genome" - alter gene expression without affecting the baseline genetic code. They are the reason why cells in different parts of the body do different things. For example, liver genes are turned on in your liver but not elsewhere, even though every cell in your body contains all your DNA information. For humans, much of this happens when we are embryos before we are born, with various chemical signals switching on and off genes in various parts of the body.

The recent report The Honey Bee Epigenomes: Differential Methylation of Brain DNA in Queens and Workers, by Professor Ryszard Maleszka from The Australian National University’s College of Medicine, Biology and Environment and colleagues, details the extensive molecular differences in over 550 genes in the brains of worker and queen bees as a result of queen bee feeding with royal jelly.

The work is quite profound as it is a step towards understanding how our environment can change our DNA. There is a growing body of evidence that suggests some epigenetic traits may be passed on to following generations rather than just affecting the individual, and this could drastically change our understanding of the process of evolution. The work also has implications for the nature vs. nurture debate, if indeed our nurture can actually change our DNA - that is, our nature.

I had a fascinating chat to Ryszard about this study, the future of this work and his opinions on how this may change our understanding of evolution. Listen in to this show here (or press play below):

Please excuse the noise in the recording of the phone call.

Lyko F, Foret S, Kucharski R, Wolf S, Falckenhayn C, & Maleszka R (2010). The honey bee epigenomes: differential methylation of brain DNA in queens and workers. PLoS biology, 8 (11) PMID: 21072239

Tuesday 23 November 2010

Why noble gases do not bond

This is actually an advertisement for the Marie Curie Actions, which is part of a research push by the European Commission. Thanks to Dr Boob for putting me on to this.

Sorry for not posting any original content, or any podcast episodes, recently. Stay tuned, more coming out this week...

Wednesday 17 November 2010

Science Cheerleaders

I am really quite baffled by Science Cheerleaders. What say you? Do you think it "breaks down the stereotype?"

Friday 12 November 2010

What is the collective noun for a group of scientists?

When you're at a pub and you see a bunch of scientists in the corner, gazing at their shoes and looking generally uncomfortable, what do call them? Is it a group of scientists? A gaggle of scientists? A murder of scientists? My quick googling didn't give me an answer, so I put the question out on twitter and facebook - what is the collective noun for a group of scientists? Here is what came in:
  • A cat-herd
  • A quantum
  • A cabal
  • A tribe
  • A gaggle
  • A whiteout
  • A multipact
  • A maxineurone
  • A quadrant
  • A sample
  • A study
  • A congregation
  • A plethora
  • A nerdlet
  • A conglomerate
  • A floc
  • A concurrence
  • A quadribble
  • A thinktank
  • A confusion
  • A bunsen
  • A titration
  • A force
  • An experiment
  • A geek
  • A meter
  • A beaker
  • A discipline
  • A method
  • An examination
  • A conjecture
  • A dogma
  • An array
  • A geek
  • An ego
Do you have a particular favourite not mentioned? Let us know! I quite like "a force of scientists" - direct and to the point, scientifically relevant, and it sounds cool.

Wednesday 27 October 2010

The Piffle Paradox - or how pure mathematicians have fun

Ever wondered how pure mathematicians have fun? The following is from the 1967 paper Modern Research in Mathematics by A. K. Austin, from the Department of Pure Mathematics at the University of Sheffield. It's a send-up, by the way...

A note on piffles by A. B. Smith

A. C. Jones in his paper "A Note on the Theory of Boffles," Proceedings of the National Society, 13, first defined a Biffle to be a non-definite Boffle and asked if every Biffle was reducible.

C. D. Brown in "On a paper by A. C. Jones," Biffle, 24, answered in part this question by defining a Wuffle to be a reducible Biffle and he was then able to show that all Wuffles were reducible.

H. Green, P. Smith, and D. Jones in their review of Brown’s paper, "Wuffle Review, 48", suggested the name Woffle for any Wuffle other than the non-trivial Wuffle and conjectured that the total number of Woffles would be at least as great as the number so far known to exist. They asked if this conjecture was the strongest possible.

T. Brown, "A collection of 250 papers on Woffle Theory dedicated to R. S. Green on his 23rd Birthday" defined a Piffle to be an infinite multi-variable sub-polynormal Woffle which does not satisfy the lower regular Q-property. He stated, but was unable to prove, that there were at least a finite number of Piffles.

T. Smith, L. Jones, R. Brown, and A. Green in their collected works "A short introduction to the classical theory of the Piffle," Piffle Press, 6 gns., showed that all bi-universal Piffles were strictly descending and conjectured that to prove a stronger result would be harder.

It is this conjecture which motivated the present paper.


Not to be outdone, S. J. Farlow from the Department of Mathematics, University of Maine, wrote in the seminal A rebuke of A. B. Smith's paper, 'A Note on Piffles':

In A. B. Smith's recent paper, 'A Note on Piffles', The American Mathematical Monthly, 84, p. 566 he completely fails to mention one of the most significant results yet discovered in Piffle Theory, namely A. K. Puddle's paper, 'Products of Planar Piffles'.

In this short but succinct note Puddle proves that a denumerable product of Pi Piffles is in fact a P-Pi Piffle (assuming of course pairwise permutation of the Piffles). That Puddle's condition was only necessary and not sufficient did of course not detract from this significant work—but did in fact open the door to the well-known Piffle Paradox (of which I'm afraid Professor Smith is completely unaware).

Readers interested in obtaining a complete up-to-date history of the Piffle should consult P.U. Piper's comprehensive review, The Piffle: 1840-1978 (Pauper Press). Here Piper describes some modern approaches taken by American Mathematicians during the last fifteen years. I am sorry to say that the classical treatment of Piffles taken by most English Mathematicians, notably the work of author Smith, is, by American standards, obsolete even before it hits the printing press. In particular the classic theorem of Smith, Jones and Brown on Polynomial Piffles would be only a simple corollary to Puddle's basic result on Homological Piffles. In fact it is fairly safe to say that all the English results so far on Piffle Theory can be subsumed in Piper's short note, 'Spectral Decompositions of Partial Piffles', American Piffle Review, 27, pp. 1-2.


Hat-tip to Let ε < 0 where I first saw this lovely work. I believe the original paper came out of discussions between mathematicians and educators regarding good (and presumably bad and confusing) forms of mathematics education. I dare say that had I seen this treatise in undergraduate maths, or had Homological Piffles been mentioned at least once, I wouldn't have transferred from Metric Spaces to Astronomy....

Austin, A. (1967). 3183. Modern Research in Mathematics The Mathematical Gazette, 51 (376) DOI: 10.2307/3614400

Farlow, S. (1980). Three Mathematical Satires A rebuke of A. B. Smith's paper, 'A Note on Piffles' International Journal of Mathematical Education in Science and Technology, 11 (2), 285-304 DOI: 10.1080/0020739800110222

Tuesday 19 October 2010

Ep 136: Sexual Selection

It's about time we put out a new podcast!

In this edition, I chat to Associate Professor Robert Brooks, Director at the Evolution and Ecology Research Centre, UNSW about sexual selection.

Charles Darwin described sexual selection as "struggle between the individuals of one sex, generally the males, for the possession of the other sex" and nature abounds with strange examples of where animal features have evolved way past their survival needs - for example, reindeer antlers, peacock plumes and quite possible human vocabulary - humans and other primates survived quite nicely without a wide vocabulary, why do we now possess one?

Rob is a leading world expert in the area, listen in to find out what he had to say.
Listen in to this show here (or press play below):

If you would like to hear more about the science of sex, check out The Beer Drinking Scientists episode Let's talk about sex.

Brooks, R. (1999). The dark side of sexual selection Trends in Ecology & Evolution, 14 (9), 336-337 DOI: 10.1016/S0169-5347(99)01689-4

Brooks, R., Hunt, J., Blows, M., Smith, M., Bussiére, L., & Jennions, M. (2005). EXPERIMENTAL EVIDENCE FOR MULTIVARIATE STABILIZING SEXUAL SELECTION Evolution, 59 (4), 871-880 DOI: 10.1111/j.0014-3820.2005.tb01760.x

Monday 11 October 2010

2SER Subscriber Drive - subscribe and I will give you a cuddle

Between October 11 and October 23, Sydney community radio station 2SER is running its annual subscriber drive. 2SER is home to the science program Diffusion Science Radio to which I regularly contribute, and I also record interviews and podcasts using their studios.

Community radio stations are partially funded by various levels of government, but in the main, they draw their revenue from sponsors and listeners. Subscribing to 2SER is pretty cheap:

$33 - Concession
$66 - Working
$120 - Passionate
$120 - Bands / Artists
$120 - Organisation
$250 - Business
$600 - Lifetime

The theme for this year's drive is Hello Radio, my old friend - so go on, help out a friend in need! Check out the subscriber page to contribute and for more information on the subscriber packs that will be delivered to your door, and the prizes you could win, should you subscribe.

Subscribing to 2SER helps keep independent radio on air - for instance, you will be hard pressed to find quality science radio in Australia outside of the ABC - generally, community radio stations house this type of broadcasting. And as Diffusion is a relatively small operation, we can respond to listener questions in a personal way. Each member of the team is an actual trained and working scientist, as opposed to a journalist, which means that we can bring authority to the topics at hand, as well as having access to Australia's best scientists. The same can be said of 2SER's other talk shows.

To the freebies - if you subscribe, you will receive:
  • Spunk Subscriber Pack containing tracks from Bear Hug, Menomena, Holly Throsby, Sufjan Stevens, Wild Nothing, Caitlin Rose, Active Child, Sonny and the Sunsets, The Books, Olof Arnalds, Mountain Man, Joanna Newsom, Gold Panda, Anthony and the Johnsons plus Jeff The Brotherhood;
  • Three months subscription to Time Out Sydney:
  • Sticker, Fridge Magnet.
The major prizes are:
  • Return flights To Malaysia for two - valued at $1890;
  • A $1000 bike pack;
  • A 12 month membership to Boxing Works, Surry Hills - valued at $1308;
  • 12 months of music - valued at $1440;
  • 2 courses at 2SER School Of Radio - valued at $1320;
  • A DJ course and music production course with DJ warehouse - valued at $540;
  • Oxx Digital and Internet radios - valued at $300;
  • 10x Double Passes To Peats Ridge 2010/11 - Valued At $600.
Plus, if you subscribe and mention Diffusion (or, if you want, me!) then I will give you a cuddle. What more could you want? Check out the subscriber page for more.

Tuesday 28 September 2010

How close could an average spaceship get to the Sun before melting?

I must start by apologising for being so lax in posting articles and podcast episodes over the last month. We've recently bought a house and moved in, and this process has taken up nearly all my time, given me multiple headaches and left me without the Internet at home.

A while back we put a call out for your burning science questions, and plenty of great questions came in on this site, via email, on twitter (@westius) and over at facebook. I apologise for my delays in publishing these questions and their answers - you can follow the questions that have already been answered in the podcast or on the blog using the Science Week tag.

One interesting question that came in was How close could an 'average' spaceship get to the Sun before melting? Here is an answer from a much more intelligent person than I, Physics PhD holder and all round good bloke, David Bofinger.

An old-fashioned spaceship would probably be made of aluminium, a more modern one might be made of a mixture of aluminium, graphite fibre and polycyanate. Assuming you want the spaceship to actually melt, rather than just fall to bits because a few bits melted, then you probably want to raise it to the melting point of aluminium, which is 933 Kelvin. Of course it will take a lot less than that to kill any crew and cook any electronics on the ship. But melt you asked for and melt we shall give.

We'll assume for the moment that the spaceship is a simple sphere and that we haven't done anything clever to keep the spaceship cool. It will heat up to a temperature such that it's radiating away as fast as it's absorbing heat from the sun. The closer it gets to the Sun the more it absorbs, the more it needs to radiate so the higher its temperature will get.

If we put it in orbit around the Earth, then it's about 150 million kilometres from the Sun and the temperature it reaches is 279 Kelvin, i.e. about 6 degrees Centigrade. (Earth is mostly warmer than this because it has greenhouse gases in its atmosphere.) To melt the aluminium in the spaceship we need to take it into 13 million kilometres, about a twelfth of the distance from Earth and four times closer than Mercury.

Of course there's all sorts of tricks we can play to get closer. We can make the spaceship silvery on the side facing the Sun and black on the side facing space. That will make it absorb less and radiate more. If we made it as white as snow on the Sun side and black as coal on the space side then we could get in as close as 6 million kilometres, about eight times closer than Mercury and twenty-five times closer than Earth. If we made the spaceship long and thin and pointed it toward the sun we could maximise our ability to dump heat compared with how much we absorbed. That might get us in a little close yet. If we pull out all the stops we might do as well as NASA's planned solar probe, which intends approaching within 6.6 million kilometres of the sun while staying cool enough to have functional electronics and cameras.

The moral is that if you want to go close to the sun you don't want an average spaceship, but something built to take the heat.

If you have an alternate opinion, I'd love to hear it.

Monday 6 September 2010

Dodgy cricket odds

The cricket world has recently been rocked by allegations of match-fixing against the Pakistan team.

The News of the World set up a sting to catch sporting-agent Mazhar Majeed correctly predicting when three no-balls would be bowled during the recent Lords Test Match between England and Pakistan. Whilst this in itself is not match-fixing (it's called spot-fixing - fixing certain events in a days play to win exotic bets), it's a smoking gun pointing towards further corruption.

So what are the odds of correctly picking three no-balls in a day's Test play? Could Majeed have just been lucky?

Let's assume there are 90 overs in a day's play, and on average 10 no-balls and 3 wides. This means that 553 balls will be bowled in the day. There are two ways to work out the probability of correctly choosing 3 balls as no-balls.

1) You can choose 3 random balls from 553 in 28032676 different ways. You can choose 3 no-balls out of 10 possible no-balls in 120 different ways. So mathematically, this looks like:

2) The other way to do this to imagine a big bag of marbles, where the no-balls are black and all other balls white. The first time you pull out a marble, you have 10 chances in 553 of pulling out a black marble. On the second draw, you have 9 chances in 552 and on the third you have 8 chances in 551. This looks like:

This means there are 4 chances in a million of the sports-agent fluking his result. Essentially, he's dodgy! (It is left as an exercise for the reader to prove algebraically that the above two methods are exactly the same...)

Further reading:
Forrest, D. (2003). Sport and Gambling Oxford Review of Economic Policy DOI: 10.1093/oxrep/19.4.598
Frey, James H. (1992). Gambling on sport: Policy issues Journal of Gambling Studies DOI: 10.1007/BF01024122

The Beer Drinking Scientists talk Sex

Over at my other podcast, The Beer Drinking Scientists, we like to tackle the big science topics down at the pub. And what better topic to talk about over a beer than sex?

Darren and Marc review the history of research into sexuality, including the seminal Kinsey Reports, the Masters and Johnson research into the diagnosis and treatment of sexual disorders and dysfunctions, and the more recent, and intriguing, study that Partner wealth predicts self-reported orgasm frequency in a sample of Chinese women.

We also take a look at how sex might have evolved. Why is it that it takes two people to have sex? Wouldn’t evolution be quicker if we could simply reproduce on our own? This is known as the twofold cost of sex - what are the benefits of having two people mix their genes to reproduce? Sexual Selection is another topic up for discussion. Charles Darwin described sexual selection as “struggle between the individuals of one sex, generally the males, for the possession of the other sex” and nature abounds with strange examples of where animal features have evolved way past their survival needs - for example, reindeer antlers, peacock plumes and quite possible human vocabulary - humans and other primates survived quite nicely without a wide vocabulary, why do we now possess one?

We could not possibly tackle this topic without discussing the Sexy Son Hypothesis, or without having a chat to the punters in the pub. Tune in to hear the public’s thoughts on sex, the science involved, length, width, money, style, cuteness, attraction and also hear Darren provide solace to a broken hearted drinker.

Of course, over a beer, much is talked about and you’ll have to tune in to catch the rest! Get over to The Beer Drinking Scientists website to subscribe, listen in to this show here, or press play below:

Wednesday 25 August 2010

Ep 135: Why do I sneeze at the Sun?

Do you sneeze at the Sun?

I do. My brother does. Both my parents do. In fact, we are a family of Photic Sneeze sufferers.

The Photic Sneeze Reflex (PSR), also known rather ridiculously as Autosomal Dominant Compelling Helioophthalmic Outburst (ACHOO) Syndrome (how long do you think it took researchers to figure out that acronym....) is a dominant genetic condition affecting around 10% of the population. When a sufferer moves from a region of darkness to a region of bright light - for instance, walking outside and looking at the Sun - multiple sneezes occur. Research into the disorder has yet to explain either its mechanism or an evolutionary reason for why it occurs. One theory is that there is a "short circuit" in the brain, with the stimulated optic nerve somehow triggering the sneeze reflex.

Professor Louis Ptáček runs the Laboratories of Neurogenetics at the University of California, San Francisco. The aim of the lab is to study familial disorders with strong genetic contributions, and thus localise and identify genes that cause human disease. Other conditions in which he is interested include migraine and epilepsy, and an intriguing condition whereby certain sounds cause seizures. He considers PSR to generally be a midly annoying condition, unless you are a combat pilot, where sneezing at the Sun could indeed be life threatening.

I had a really interesting chat to Louis about PSR, and I've left the recording a little longer than usual, as we were really able to explore some fascinating ideas involved with PSR - it was a great chat. Listen in to this show here (or press play below):

Other interesting write-ups of PSR include neurotopia and Scientific American.

This topic came in as part of my call for questions for Science Week, so thanks @lisushi for the question! I'll be putting up more blogs and podcasts to answer the other questions that came in over the next few weeks.

Breitenbach RA, Swisher PK, Kim MK, & Patel BS (1993). The photic sneeze reflex as a risk factor to combat pilots. Military medicine, 158 (12), 806-9 PMID: 8108024 

Langer N, Beeli G, & Jäncke L (2010). When the sun prickles your nose: an EEG study identifying neural bases of photic sneezing. PloS one, 5 (2) PMID: 20169159 

MADIGAN, J., KORTZ, G., MURPHY, C., & RODGER, L. (1995). Photic headshaking in the horse: 7 cases Equine Veterinary Journal, 27 (4), 306-311 DOI: 10.1111/j.2042-3306.1995.tb03082.x

Songs samples in the podcast:
The Steve Wilson Band 
"Stare At The Sun"
from "Sideshows And Fairytales"
Buy at iTunes
DJ Smiths vs Markanera
 "Watching the Sun Goes Down"
from "Watching the Sun Goes Down"
Buy at iTunes
Alexis Cuadrado 
"Bright Light"
from "Puzzles"
Buy at iTunes

Sunday 22 August 2010

What if we decided election winners using the Big Brother voting method?

This weekend, Australia went to polls in the 2010 Federal Election.

Elections make for some fascinating number analysis. As readers from a while back might remember, I love the statistics of elections. Australia has a preferential voting system, whereby voters list the candidates by order of preference. As opposed to the first past the post system used in Britain, the winner is not decided by who receives the most primary votes, but rather who is the most preferred candidate. Sometime soon I will write a post on the various voting systems used worldwide - see Plus for a great introduction to various voting methods - but for today we ask the question, what would happen if we used the Big Brother voting system?

Big Brother, for those who have been living under a rock, is a TV show in which around 15 house-mates are watched around-the-clock by TV cameras, which broadcast the show live to viewers who, at the end of each week, vote someone out of the house until there is only one contestant left. What if, instead of voting in political parties, we voted out the parties we didn't like?

Let's run an example on my local electorate, Grayndler. At the time of writing, the primary vote distribution looked like this (~70% of the total vote has been counted):

Name Party Votes
James Michael Cogan Socialist Equality Party (SEP) 849
Pip Hinman Socialist Alliance (SAL) 879
Alexander Dore Liberal Party (LIB) 16691
Anthony Albanese Australian Labor Party (ALP) 32406
Sam Byrne Greens (GRN) 17633
Perry Garofani Australian Democrats (DEM) 851

Total 69309

Under the current voting system, it looks like the Labor Party may win the seat, although there is still some uncertainty about this as Liberal party preferences will mostly flow to the Greens, meaning that on preferences there is some small chance that the Greens will win the seat. But what about under our new Big Brother system?

To test out this system, we need to make a few assumptions regarding preferences. We have no idea how voters listed their preferences - whilst, for instance, most Greens voters will preference Labor over Liberal, and many Socialist Alliance voters will preference the Greens over Liberal, I simply don't have the data. Anecdotally, many voters follow party "how to vote cards", meaning that they order their preferences how their favoured parties tell them. So let's assume, for the sake of this analysis, that every voter does this. Taking the party preferences from their senate preference flows list, we see that the parties list their preferences in the following way:

1 2 3 4 5 6
Socialist Equality Party (SEP) SEP GRN SAL LIB ALP DEM
Socialist Alliance (SAL) SAL GRN ALP SEP DEM LIB
Australian Labor Party (ALP) ALP GRN DEM SEP SAL LIB
Australian Democrats (DEM) DEM SAL SEP GRN ALP LIB

It was difficult to come up with the SEP list of preferences as they have three preference lists for the Senate and didn't actually make any effort to order the other parties in terms of preference but rather simply numbered their preferences down the page according to where the parties were written on the ballot. Weird. I suspect that because of this I have their preferences incorrect, but this is simply a worked example so don't hold it against me!

Let's now cross to Gretel Killeen at the Big Brother house.....

Week 1:
After battling it out with a number of pointless challenges and staying up late because they had nothing else to do, the first eviction saw an overwhelming majority of voters evict the Liberals. Using the vote table above and counting up the number of times a party was put as last preference on the ballot, the number of votes for eviction were as follows:

Week 1
Socialist Equality Party (SEP) 0
Socialist Alliance (SAL) 16691
Liberal Party (LIB) 51769
Australian Labor Party (ALP) 0
Greens (GRN) 0
Australian Democrats (DEM) 849

Week 2: 
A dancing-doona between the two socialist parties was the highlight of week 2. With no Liberals to evict, most voters had to turn to their second least-liked party. The Socialist Alliance pulled in an extra 32406 votes - for those playing along at home, these are all the voters who put Labor at number 1 on the ballot box and the Liberals at number 6, whilst the Socialist Equality Party, the ALP and the Democrats also picked up extra eviction votes. It's time to go....  Social Alliance.

Week 1Week 2
Socialist Equality Party (SEP) 017633
Socialist Alliance (SAL) 1669149097
Liberal Party (LIB) 51769-
Australian Labor Party (ALP) 0851
Greens (GRN) 00
Australian Democrats (DEM) 8491728

The following weeks saw an attempted turkey-slap by Labor on the Greens and an impressive Bum Dance by the Democrats. However, in the final week of the show, The Greens took out the seat of Grayndler using the Big Brother eviction rules.

Week 3Week 4Week 5
Socialist Equality Party (SEP) 66730--
Socialist Alliance (SAL) ---
Liberal Party (LIB) ---
Australian Labor Party (ALP) 85135175-
Greens (GRN) 0017542
Australian Democrats (DEM) 17283413451767

75% of voters preferred the Democrats to be evicted in the final round.

There are other ways in which one could run a Big Brother-style election and generally these methods would be likely to find the least offensive, rather than most preferred, party. I'd love to see this method run across the whole parliament!

Tuesday 17 August 2010

Is the Taliban training monkeys to fight in Afghanistan?

Sometimes you gotta love the internets. A story recently popped up that the Taliban was training combat monkeys to fight wars in Afghanistan. The original popped up on the Chinese People's Daily Online (I caught this story on and opened with:

Afghanistan's Taliban insurgents are training monkeys to use weapons to attack American troops, according to a recent report by a British-based media agency.

It doesn't actually identify the British-based agency, but continues:

Reporters from the media agency spotted and took photos of a few "monkey soldiers" holding AK-47 rifles and Bren light machine guns in the Waziristan tribal region near the border between Pakistan and Afghanistan.... According to the report, American military experts call them "monkey terrorists." ... The emergence of "monkey soldiers" is the result of asymmetrical warfare. The United States launched the war in Afghanistan using the world's most advanced weapons such as highly-intelligent robots to detect bombs on roadsides and unmanned aerial vehicles to attack major Taliban targets. In response, the Taliban forces have tried any possible means and figured out a method to train monkeys as "replacement killers" against American troops. 

The report suggests that the monkey killers will arouse Western animal protectionists to pressure their governments to withdraw troops from Afghanistan and that the CIA trained monkeys to kill in the Vietnam War.

What a wonderfully weird, and bogus, story!

The photo of the terrorist monkey at the heart of this story (above) was found by Jeff Schogol at to be photoshopped and Live Science went out and asked some actual scientists (gasp!) whether monkey terrorists were possible - they said no...

You can watch CNN's video of the saga here, view some pretty funny comments and images over at fark, but for the best coverage, check out the Taiwan Animated News version below. I can't understand a word of it, but you really don't need to. Make sure you stick it out till the hilarious animation.

Wednesday 28 July 2010

Classic Science Videos

If you understand all the mathematical references in the following video, you're doing well. Enjoy the classic mathematical a capella (bet you thought you'd never read that sentence) Finite Simple Group (of Order Two).

If you think that dance is the best medium to portray protein synthesis, then the next video is for you. Made in 1971 by Robert Alan Weiss for the Department of Chemistry of Stanford University, this short film is narrated by Paul Berg, 1980 Nobel prize winner for Chemistry. It makes me wish I had taken science in the 70s - there is no other word than awesome to describe seeing 30s ribosome in the form of hippy interpretative dance. Gotta love the acid-trip music.

Wednesday 21 July 2010

Ep 132: Science of Superheroes - The Hulk

The science of superheroes is taking a green and nasty turn this week as we discuss the largest superhero of them all, The Hulk. Join myself and our regular superhero expert Dr Boob as we delve into the science of how we might realise The Hulk in the lab. It was one of the more entertaining interviews I have done for the podcast.

Listen in to this show here (or press play below), and read further for more info:

The Hulk is alter-ego of Dr Bruce Banner, who allegedly bares a striking resemblance to Dr Boob. Banner is a reserved physicist who involuntarily transforms into The Hulk when triggered by a strong emotion such as anger, fear, terror or grief. The Hulk himself is a massive green monster who gets stronger the angrier he gets. He also has bullet-proof skin.

The Hulk’s origin story includes depends on whether we are looking at the comic book Hulk, the Hulk of the two recent movies, or The Incredible Hulk of the TV series (in which it is David Banner, not Bruce Banner, who metamorphoses into The Hulk).

The 2003 movie version "Hulk" includes many of the topics we discuss in the podcast. The movie starts with genetics researcher David Banner – Bruce Banner’s father - working with the military to "improve" human DNA. The opening credit sequence depicts experiments with jellyfish and starfish DNA, and Banner’s notepad mentions bioluminescence. This suggests that the Hulk gets his green colour from jellyfish DNA as some jellyfish bioluminesce at around 450 nm, which is at the blue/green end of the spectrum. In 1961, Osamu Shimomura extracted green fluorescent protein and another bioluminescent protein, called aequorin, from Aequorea victoria while studying bioluminescence. He eventually received the Nobel prize in Chemistry in 2008 for this work. The mention of starfish is also interesting because, as we found with Wolverine, starfish and sea cucumbers have great healing powers and are able to regenerate lost limbs. Evidently, Banner wanted to splice bioluminescence and improved healing into human DNA.

Banner’s experiments then moved to lizards and monkeys, but unfortunately they all died. Naturally, he then decided if his experiments did not work on animals, he would try them on himself – clearly, ethics committees are not part of superhero science. After conducting experiments on his own DNA, he eventually passes on his mutant DNA to his unborn son Bruce. Once David realises this, he changes his approach and works to cure his son of his genetic afflictions, however the research is shut down and an explosion kills David’s wife. David is taken to a lunatic asylum and Bruce is adopted.

Years later, Bruce has followed his father’s line of work and is conducting military research – Bruce’s area of interest is the use of nanomeds in soldiers. This might include such things as targeted drug delivery for rapid recovery from injury. An experimental accident subjects Bruce to an enormous dose of gamma radiation which “activates” his mutant DNA (possibly combining with the nanomeds) and the building rage/stress transforms him into The Hulk for the first time.

Whether or not this is scientifically possible – well, that’s the topic of the podcast so tune in!

Other issues that we discuss include:
  • Gamma radiation and radiation poisoning;
  • Genetic transfer and gene therapy – could David Banner change his own DNA in such a way that this change would be copied to his progeny? For more information, check out the Weismann Barrier;
  • The Hulk’s size – is it possible to rapidly increase your size? Simple conservation of mass equations would suggest no, and bacteria in a Petri dish generally have a 24 hour doubling time. There are also enormous metabolic requirements involved – we need to have resources available to feed these growing cells and Bruce Banner is not excessively fat. Perhaps to do this we need to accelerate Bruce Banner to the near the speed of light, at which point he may relativistically pick up some mass - however, this is not particularly practical!
  • The Hulk’s strength – is it possible to rapidly increase your strength?
  • The Hulk's healing properties - could we use some of the science of Wolverine here?
  • The materials used to create bullet-proof skin. The toughest skins in the animal kingdom are crocodile, elephant, shark and armadillo; however none are bullet (and knife) proof;
  • What materials could we use to make his "one-size-fits-all" pants? You will notice that no matter what size Bruce Banner or The Hulk are, and no matter what the ripped state of his other clothes, his undies always fit.
  • And of course, whether The Hulk has irritable bowel syndrome and wears giant green snuggies.
    Hope you enjoy this show - we certainly enjoyed recording it, as you will be able to tell by the end! Listen in to this show here (or press play below):

    NB: I've now discovered there's a Red Hulk - future show perhaps?
    Samples in this podcast are broadcast courtesy of ioda PROMONET. They were:

    The Toxic Avenger
    "Superheros 2007" 
    from "Superheroes" 
    Buy at iTunes
    from "Little Baby Souls"
    Buy at iTunes
    Candye Kane
    from "Superhero"  
    Buy at iTunes
    Ninja Kodou
    "Superhero (Psychedelic Man)"
    from "Ninjutsu"  
    Buy at iTunes

    Shimomura, O., Johnson, F., & Saiga, Y. (1962). Extraction, Purification and Properties of Aequorin, a Bioluminescent Protein from the Luminous Hydromedusan,Aequorea Journal of Cellular and Comparative Physiology, 59 (3), 223-239 DOI: 10.1002/jcp.1030590302

    Moghimi, S. (2005). Nanomedicine: current status and future prospects The FASEB Journal, 19 (3), 311-330 DOI: 10.1096/fj.04-2747rev