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Posts Tagged ‘medicine’

IgNobel Prize Winners!

September 29, 2011 Leave a comment

Well, the IgNobel Prizes wrapped up not too long ago. Scicurious was live blogging the event and there was also a live webcast.

And the winners are:

A group from Europe won the Physiology award for demonstrating that yawns are not contagious in Red-Footed tortoises.

A group from Japan won the award for Chemistry by demonstrating the ideal amount ofwasabi to put in the air in order to wake people up. The purpose? A wasabi fire-alarm!

A couple of studies demonstrating how people make decisions when they really, really have to pee won the award for Medicine.

A group from Oslo won the Psychology prize for studying why people sigh. 

The Literature prize was given to John Perry of Stanford University for his theory of “Structured Procrastination“.

The Biology prize was given to a couple guys hailing from Canada, Australia and the USA for discovering a type of beetle that mates with stubby beer bottles.

A bunch of loons (e.g. Harold Camping) won the Mathematics prize for predicting the world would end and being wrong.

The Peace prize was awarded to Arturas Zuokas, the mayor of Vilnius, Lithuania, for driving over an illegally parked luxury car with an armored tank.

The Public Safety prize was given to John Senders of the University of Toronto for conducting a driving safety study by having someone drive down the highway and have avisor repeatedly hit them in the face.

And finally, (and most importantly!) the Physics prize was given to a group from France and the Netherlands for studying why discus throwers get dizzy, but hammer throwers don’t. Very important with the 2012 Olympics coming up!

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Ryan

Watch the IgNobel Prizes Tomorrow!

September 28, 2011 Leave a comment

The 21st 1st (no typo) Annual IgNobel Prizes are tomorrow. What are the Igs, you ask?

The Ig Nobel Prizes honor achievements that first make people laugh, and then make them think. The prizes are intended to celebrate the unusual, honor the imaginative — and spur people’s interest in science, medicine, and technology.

Awarded by Improbable Research, we will learn tomorrow whose real-life research is the weirdest, coolest, and funniest.

For example, last year’s physics prize went to

Lianne ParkinSheila Williams, and Patricia Priest of the University of Otago, New Zealand, for demonstrating that, on icy footpaths in wintertime, people slip and fall less often if they wear socks on the outside of their shoes.

Here’s the reference to prove it!

To hear about it live, you can watch the webcast or you can watch Scicurious (one of my fav science bloggers) live blog the event.

It is always entertaining and reminds us all why we love science!

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REMINDER: This blog is moving! The new location is http://www.aquantumofknowledge.com/ 

The new RSS Feed is: http://feeds.feedburner.com/AQuantumOfKnowledge

Remember to update your subscriptions! This site will no longer be supported after September 30, 2011. 

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Ryan

If Your Bandage is Glowing, That’s Bad…

September 17, 2011 Leave a comment
Polymer

A polymer and fluorescent dye work together to cause a bandage to glow in the presence of infection.

A team of researchers at the University of Sheffield has developed an interesting way of detecting bacteria in a wound (I know, gross).

The researchers found that a polymer attached to a fluorescent dye on bandage can detect when bacteria or other harmful organisms come into contact with the wound. The polymer changes shape when the bacteria are present, activating the dye and emitting ultraviolet light.

The technique was mainly developed with military applications in mind. Being able to easily and quickly identify infected wounds on the battlefield could help significantly reduce the severity of injuries.

“If you know you’ve got infection it’s going to change how you treat your soldiers, it’s going to change how you’re going to treat those patients in the home,” Sheffield researcher Sheila McNeil said. [UPI.com]

At the moment, the technique has only been applied to artificial tissues. However, it currently takes several days to confirm the presence of infection, so there is quite an interest in expanding the technique to human trials.

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REMINDER: This blog is moving! The new location is http://www.aquantumofknowledge.com/ 

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Ryan

Just How Dilute are Homeopathic Remedies?

March 4, 2011 Leave a comment

Homeopathy operates on a principle that the more dilute a “remedy”, the more potent it becomes.

Homeopathy makes no sense, and it doesn’t work, but people still cling to it even though it is simply an over glorified placebo effect.

Many homeopathic remedies are diluted to the point that not a single molecule of the original ingredient remains. Just HOW dilute is this?

Steve D wrote a post called “Putting Homeopathy in Perspective” and uses a very pretty visual: Felicia Day.

For example, one such homeopathic dilution is called 3C, which means the remedy was diluted to 1 part in 100, 3 times. This is approximately the number of Felicias in the world who are Felicia Day:

The post is really quite awesome and very well illustrates how ridiculous homeopathy is. Especially since some homeopathic remedies go up to 200C! To have even a single molecule of the original substance still in a sample of a 200C dilution, you would need a sample the size of not only our ENTIRE UNIVERSE, but

100 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000

ADDITIONAL UNIVERSES! (Thats 10320 in scientific notation).

It boggles the mind.

The Physics of MRI

February 9, 2011 3 comments

MRI being performed. Via Wikimeda Commons

Phew. I know, right?!

I’ve been saying I’ll write a post about the physics of MRI for months. Never got around to it. Mostly because I knew that since magnetic resonance imaging (MRI) was my field of research, that I would want to go into a lot of detail. I loved the time I spent doing MR research, and now I’ll finally share with all of you how it works.

Let’s start at the beginning.

We are all made of atoms. Atoms consist of a nucleus (made of neutrons and protons) orbited by electrons. The most common atom in our bodies is Hydrogen, which is a single proton orbited by a single electron. It is the simplest atom in nature, and it is quite fitting that it makes up the majority of our bodies.

We are mostly made of hydrogen because we are mostly water. Water has 2 hydrogen atoms and 1 oxygen atom (H20). When we do an MRI, what we are actually taking an image of is the hydrogen in our bodies.

How is that done? Well protons have charge, a positive charge. Any particle that has charge also has what is called a magnetic moment. A magnetic moment is essentially a measure of the strength and direction of the magnetic field of  particle. For a proton, the magnetic moment looks like this:

A proton (red circle) and it's magnetic moment (arrow)

Usually, all the magnetic moments in your body are jumbled about in all directions. That’s why you are not magnetic. When this is the case, we say that your net magnetic moment is zero.

Normally, all the magnetic moments in your body are jumbled around. Thus, your net magnetic moment is zero.

But if we apply a magnetic field from the outside, we can get the moments in your body to line up with the field, like so:

If we apply a magnetic field in a certain direction (blue arrow) the magnetic moments in your body will tend to align with the magnetic field.

In order to do that, we need BIG MAGNETS. That’s why MRI’s are so strong; you need that strong magnetic field to get the moments in your body to line up. (The diagram above is an exaggeration; in reality, only 1 in a million of the magnetic moments will line up with the field, on average).

How strong is an MRI magnet? Magnetic fields are measured in units of Tesla (in honour of Nikola Tesla). A typical MR scanner has a field of 1.5 Tesla. For comparison, this is about 30 000 times stronger than the Earth’s magnetic field, the field that makes a compass needle point north.

Now your body has what is called a net magnetization. This means that the magnetic moments have lined up and you are a little bit magnetic.

But that’s only half the battle. Next, we have to get some kind of signal from your body to make an image. How do we do that?

Well, have you ever swiped a credit card in a machine? What would happen if you just held it still? Would it still work?

The answer is no. Your credit card only works because the black strip in the back is magnetic. When you swipe it through the machine, it creates an electric current. This is due to Faraday’s Law, which says that a changing magnetic field in a loop of wire will create an electric current in that wire.

When you swipe a credit card through a credit card machine, you induce an electric current in the machine.

We can apply this concept to your body too now that its been magnetized by the MRI machine. You see, MRIs actually have a radio transmitter/receiver inside of them as well. How does THAT help?

Unlike a credit card, we can’t swipe YOU through the MRI machine. That’s not feasible. But we can manipulate the fact that you are now magnetized. This can be done using a radio-frequency pulse. Basically this is just a short, intense burst of radio waves at your body. This will actually make your net magnetic moment spin.

If your net magnetic moment is now spinning, it creates the exact same effect as if we were to swipe you through the MRI machine: it generates an electric current in a receiver in the MRI. Cool eh?

Ok so now we have a signal from your body by magnetizing it, and then making that net magnetization vector spin. How does that make an image?

So we made your net magnetization spin by using a radio-frequency pulse. How fast it spins depends on how strong the magnetic field is. So what MR scanners do is they make the magnetic field a bit different at each point in your body. That way, the magnetization from each part of your body spins at a different rate (or frequency) and we can then determine what part of your body is giving the signal.

Confused? Think of it this way:

Let’s say you had a piano. You hit a key on the left side of the piano and what happens? It makes a deep, low-frequency sound. Now you hit a key on the other end of the piano and you get a high-pitched, high frequency sound.

Different keys on the piano make different frequencies of sound. You can get an idea of what key someone hit from the frequency of the sound, without actually seeing the piano.

Now pretend you weren’t looking at the piano at all, and someone else hit a key. If you hear a low-frequency sound, you know they hit a key on the left side of the piano. If you hear a high frequency sound, you know it came from the right side. You were able to determine the position of the key by its frequency.

Its the exact same idea in MRI. Using the frequency of the signal we get, we can determine where in your body that signal came from. We then put all those signals from all parts of your body together, and we get an MRI image.

MRI of the head (Photo: NASA)

I know, there’s a lot of steps to MRI,  so I’ll recap:

  1. We magnetize your body by using a really big, strong magnet.
  2. We make your net magnetization spin using a radio-frequency pulse.
  3. This spinning magnetization generates an electric current in the radio receiver in the MRI machine.
  4. We can tell where in your body this signal came from by its frequency.
  5. Putting all the signals from all over your body together, we can make an image.

So there you go. Simple right?

If you want some more information you can check out the MRI article on HowStuffWorks.

Or if you want something a little more technical and goes a bit deeper into MR theory (e.g. relaxation, pulse sequences), check out this online book by J.P. Hornak, or the Wikipedia page on the physics of MRI.

Happy learning!

Big Skeptical Wins: Andrew Wakefield “Fraud” and Power Balance Bull

January 6, 2011 Leave a comment

The blogosphere is teeming with articles regarding a couple of recent wins for skepticism. I’ll save the best for last.

The Power Balance Wristband

The first such win is the admission by the makers of Power Balance, a bracelet designed to increase sport performance. How you ask? The website states that

Power Balance is based on the idea of optimizing the body’s natural energy flow, similar to concepts behind many Eastern philosophies. The hologram in Power Balance is designed to resonate with and respond to the natural energy field of the body.

Sound like bullplop? Well it is bullplop.

Making these kinds of statements was a violation of Australian trade practices. Why? The press release to Australian media by Power Balance says it all:

In our advertising we stated that Power Balance wristbands improved your strength, balance and flexibility.

We admit that there is no credible scientific evidence that supports our claims and therefore we engaged in misleading conduct in breach of s52 of the Trade Practices Act 1974.

If you feel you have been misled by our promotions, we wish to unreservedly apologise and offer a full refund.

Big time win for the skeptical movement, since they were instrumental in bringing about this admission from Power Balance.

So that’s great. But this one is awesome!

Andrew Wakefield

Our dear friend Doctor Andrew Wakefield, whose study linking vaccines to autism (retracted study, btw) sparked an anti-vaccine movement and a huge public health risk, is in the news again. If you have read my blog before, you know that I am not his biggest fan.

Although he has had his medical license stripped and paper retracted by the Lancet, the anti-vaccine movement persisted, painting Wakefield as some kind of martyr; hung out to dry by Big Pharma for trying to tell the “truth” about vaccines.

Well yet another blow has been struck against this movement, and its a doozy.

Journalist Brian Deer has written a feature in the British medical Journal BMJ accusing Wakefield of falsifying his data by altering the medical histories of all the subjects in his study.

After seeing the data, the father of one of the children in the study said

His misrepresentation of my son in his research paper is inexcusable. His motives for this I may never know.

The piece is well written and documents Deer’s investigations into Wakefield’s research. I encourage you to read the whole text, but here are the key points:

  • Three of nine children reported with regressive autism did not have autism diagnosed at all. Only one child clearly had regressive autism

  • Despite the paper claiming that all 12 children were “previously normal,” five had documented pre-existing developmental concerns

  • Some children were reported to have experienced first behavioural symptoms within days of MMR, but the records documented these as starting some months after vaccination

  • In nine cases, unremarkable colonic histopathology results—noting no or minimal fluctuations in inflammatory cell populations—were changed after a medical school “research review” to “non-specific colitis”

  • The parents of eight children were reported as blaming MMR, but 11 families made this allegation at the hospital. The exclusion of three allegations—all giving times to onset of problems in months—helped to create the appearance of a 14 day temporal link

  • Patients were recruited through anti-MMR campaigners, and the study was commissioned and funded for planned litigation

     

So basically, he lied. He’s a dirty rotten liar-liar-pants-on-fire.

But what was his motivation? From the CNN news article:

Deer said Wakefield “chiseled” the data before him, “falsifying medical histories of children and essentially concocting a picture, which was the picture he was contracted to find by lawyers hoping to sue vaccine manufacturers and to create a vaccine scare.”

According to BMJ, Wakefield received more than 435,000 pounds ($674,000) from the lawyers.

Wakefield continues to defend himself by playing the fall-guy to Big Pharma:

Wakefield dismissed Brian Deer, the writer of the British Medical Journal articles, as “a hit man who has been brought in to take me down” by pharmaceutical interests.

The evidence against Wakefield was already overwhelming. But this story has hit the news media hard. It is a huge blow to the anti-vaxxers. Why do I think this? Well what did the anti-vaccine movement’s and Andrew Wakefield’s most prolific and outspoken public relations person, Jenny McCarthy, say about this story?

Actress Jenny McCarthy, founder of Generation Rescue and whose son also has autism, declined to comment on Wednesday’s developments

Your friends are abandoning you Andrew Wakefield. The truth is finally starting to become clear to everyone. You have duped a generation of mothers into thinking that vaccines cause autism, and children have died because of it.

An Actual (kind of…) Immaculate Conception

December 30, 2010 Leave a comment

Discoblog has released their top 10 weirdest science stories of the year, and number 1 is also one of my favourites.

It is a case report from the British Journal of Obstetrics and Gynaecology, entitled:

“Oral conception. Impregnation via the proximal gastrointestinal tract in a patient with an aplastic distal vagina. Case report.”

They have the full text on their blog here, but I will summarize.

A 15-year old girl is admitted to hospital with a stab wound to the abdomen, received during a knife fight between her ex-boyfriend and her new boyfriend. She was treated and released a few days later.

278 days after the incident, she came back to the hospital with severe abdominal pain. Turns out she was pregnant. However…

Inspection of the vulva showed no vagina, only a shallow skin dimple was present below the external urethral meatus and between the labia minora. An emergency lower segment caesarean section was performed under spinal anaesthesia and a live male infant weighing 2800 g was born

So the girl had no vagina. So how did she get pregnant?

Just before she was stabbed in the abdomen she had practised fellatio with her new boyfriend and was caught in the act by her former lover. The fight with knives ensued. She had never had a period and there was no trace of lochia after the caesarean section…

A plausible explanation for this pregnancy is that spermatozoa gained access to the reproductive organs via the injured gastrointestinal tract.

Yes, you read that right. She went down on her boyfriend, got stabbed, and the sperm went from her stomach into her reproductive system.

If that’s not miraculous, I don’t know what is. Although the author of the case study does say that

The fact that the son resembled the father excludes an even more miraculous conception.