Running and Breathing

On a recent NOVA podcast (09/03/2010 "Chasing Down Dinner"), David Levin talked about the way animals breath.

A quadruped mammal is four legged.  Cows, zebras, and dogs are examples.  In these animals, their stride is synchronized with their breathing.  A stride is one full cycle of leg movement while walking or running..  For instance, in a human, a stride is two steps.  When running, a quadruped's breathing is aided by the movement of the muscles and skeleton.

Here is a picture of a contraption put together by a physiology professor to teach how this happens.  "A" shows the animal moving the front legs forward during running.  The lungs expand at the same time and the animal inhales.  "B" shows the back legs coming forward and the animal would then exhale.  The ratio of stride to breath in a quadruped is 1:1.  One stride, one breath.  When the stride is lengthened, the volume of air into the lungs is increased.

As humans, our natural inclination is to also breath in synchrony to our stride.  But because we are upright and on two feet (bipedal) the ratio is different and can be more flexible.  The normal ratio is 2:1. Two strides to one breath.  A slow run can change that ratio to 4:1.

Humans, as a whole, are better adapted to endurance rather than speed.  Dennis M. Bramble, a biomechanist and vertebrate biologist at the University of Utah in Salt Lake City, and Daniel E. Lieberman, a biomechanist and anthropologist at Harvard University, have been studying the history of running in human beings.  They have come to the conclusion that our ancestors had an advantage with this ability to run long distances.  The animals they were chasing could not sustain a long distance.  Quadrupeds cannot pant when galloping, so their bodies would overheat and they would have to stop and try to cool off.  Meanwhile, the humans would continue in the chase and catch up.  The animals would then run again and soon were too overheated to run any longer, making it relatively easy to catch dinner.

Now you have heard something interesting.

http://advan.physiology.org/content/33/4/315.full
http://findarticles.com/p/articles/mi_m1134/is_3_114/ai_n13664996/

And Eye(tooth) for an Eye

Sharron "Kay" Thornton is a sixty-one-year-old woman who lives in Mississippi.  Ten years ago she lost her eyesight due to a rare skin disease, called Stevens-Johnson syndrome, that attacked her eyes, damaged her cornea (the clear window at the front of the eye), and left her blind.  She was not eligible for a cornea or an artificial cornea transplant.  Doctors tried a stem cell treatment, but it was unsuccessful.

Last year, she went to see Dr. Victor L. Perez of the Bascom Palmer Eye Institute at the University of Miami's Miller School of Medicine.  He decided to try a procedure that was developed in Italy but had never been done in the United States.  It is called modified osteo-odento-keratoprosthesis.

They took out one of her eye teeth, also called canine teeth, and part of the bone above that tooth.  They shaved it down to the proper shape and size and punched a hole in the middle, where an acrylic lens was inserted.  This was implanted into her shoulder for 3 months while they waited for the bone and the lens to fuse. 

The scars from around her cornea were removed and moist cheek tissue was used to cover the eye to rehabilitate it.  When the time was right, the tooth/bone/lens piece was removed from her shoulder and implanted in her eye.  It was carefully aligned with her retina. The bone keeps it from moving out of place. The cheek tissue is still on the eye, but has a hole where the lens pokes out.  She cannot close her eye fully, and the cheek tissue helps to keep it moist.

Here is a graphic from the Bascom Palmer Eye Institute that shows what was done.  When the bandages were removed, she had 20/70 vision!  They expect it will get better with time.

The procedure has been performed on 600 people around the world.  Very ingenious.  It seems to work best for people who have been blinded by chemical burns, thermal burns, rare reactions to drugs, and other cases where normal corneal transplants would not work.



There is another video of a man in the UK who was blind for 26 years.  You can go to youtube to watch it.

http://www.youtube.com/watch?v=L4vE7QlbVak  (7:28 min long)

Now you have heard something interesting.

The Paths of Legends

This past week I finished the book That's Not in My American History Book by Thomas Ayres. It was very interesting and had many stories -- some that were familiar and some that were new to me.  Here is one I didn't know.

Andrew Jackson, the seventh President of the United States, was the first president to have an assassination attempt on his life. It happened on January 30th, 1835. President Jackson had just attended a congressional funeral held in the House Chamber of the Capitol. As he exited, Richard Lawrence, an unemployed house painter, pointed a pistol at Jackson and fired.  The percussion cap exploded, but the bullet did not discharge.

Jackson moved toward Lawrence and started beating him with his cane. During the ensuing scuffle, Lawrence took another pistol out of his pocket and pulled the trigger. But that gun also misfired. Bystanders joined in, wrestling Lawrence to the ground and disarming him. One of them was Rep. Davy Crockett of Tennessee. (For those of you over a certain age, now is the time to start singing, "Davy, Davy Crockett. King of the wild frontier!")

About a hundred years later the Smithsonian Institute examined both of these guns and couldn't find anything wrong that would have made them misfire.

Richard Lawrence was mentally ill. He believed that he was Richard III, rightful heir to the throne of England and that President Jackson was keeping him from it.

The case went to trial. The prosecuting attorney wanted Lawrence to get the death penalty because, he said, any attack on the president of the United States is an attack on the United States. The defense attorney used the reasoning, for the first time in a court of law, that the prisoner should be found not guilty for the reason of insanity.

The jury deliberated for a very short time.  They bought the argument of the defense attorney.  Richard Lawrence spent the rest of his life in mental institutions.  

The prosecuting attorney was very disappointed.  He was the man whom you know as the author of The Star Spangled Banner, written twenty-one years earlier. It was Francis Scott Key.

Now you have heard something interesting.

I Ain't Scared of You

Toxoplasmosis.  If you are pregnant or are planning on becoming pregnant, this is one parasite you should know about and work hard at avoiding. It can pass through the placenta and negatively affect a growing fetus.  The consequences vary from mild to devastating.  It is transmitted to humans through cat feces.  It can be contracted from cleaning a cat litter tray, eating raw or undercooked meat, drinking unpasteurized milk, eating unwashed vegetables, working in the garden without gloves, or from exposure to a child's uncovered sandbox.

Dr. Rober Sapolsky calls it "Toxo."  He is a leading neuroscientist who is a professor of biology and neurology at Stanford University, as well as a research associate in Kenya.  He has received numerous awards for his scientific studies.  Here is an interview with him talking about Toxo.  It is fascinating and about 24 minutes long.  Well worth watching every minute, in my opinion.

In the life cycle of this parasite, it reproduces in the gut of a cat.  The eggs are shed in the feces, which are then picked up by rats and other animals that just might get eaten by a cat.  Toxoplasma forms cysts throughout the rat, including the brain. And yet a rat that is infected with it is perfectly healthy. That makes good sense for the parasite, since a cat would not be particularly interested in eating a dead rat. But scientists at Oxford discovered that the parasite "changes the rats in one subtle but vital way."

Rats respond negatively to the smell of a cat. The stress response in the rat goes up, and his instinct is to avoid the area where the smell was detected.  Makes sense.  When a rat is infected with Toxo, and smells a cat, the fear circuit in the rat does not activate.  Not only is he not afraid of the cat, but the sexual arousal circuit is activated slightly.  Wow!  This parasite has figured out how to get back into a cat so it can reproduce!  Just make the rat want to be around the cat, who will eat him.

When scientists in the UK looked at the genome (the genes and DNA) for Toxoplasma, they were astonished to find two versions of a gene that makes dopamine.  Dopamine is the neurotransmitter in the brain that is all about reward and anticipation of reward.  It is involved with emotional response, and the ability to experience pleasure and pain.  So in other words, this parasite has the gene that allows it to plug into the reward system of the brain.

So what about humans?  Can it affect our brains?  Besides the disaster of Toxo getting into the nervous system of a pregnant woman and her fetus, there are other things that go on in humans.

The first part of the infection might have symptoms like inflammation, sore throat, just not feeling well.  Then those symptoms disappear.  This is when the cysts form in the brain. For a rat, it is when the parasite makes the dopamine and the strange behavior of seeking out a cat occurs.  In men who are infected, their behavior can become impulsive.  Women less so.  There are two different groups, independent of each other, who have studied this and find that men who are affected are 3 to 4 times more likely to be killed in a high risk activity, such as reckless speeding in a car.

The personality of humans being changed by some invading organism is not a rare pattern.  The rabies virus changes both animal and human brains to become more aggressive. It knows how to make the host want to bite someone and pass on the particles of the virus.  And this parasite knows how to perpetuate its existence.

There are other areas that are being studied as having a possible link to Toxoplasma.  One is schizophrenia.  There is too much dopamine in the brain of a schizophrenic, and there is some evidence of a rate of increase to children whose mothers had cats when she was pregnant.  There are also questions about "cat women" being infected.  Scientist are still studying these and other aspects of this condition.

Now you have heard something interesting.

To Feel Nothing

Hansen's Disease, formerly known as leprosy, still exists around the world.  Since the development of medicines for it, it is no longer a fatal illness, nor has is it ever been highly infectious. It is a chronic illness.  The incubation period is anywhere from nine months to 20 years.  That makes it very difficult to pinpoint where or when one has been exposed to the disease.

The bacteria that causes Hansen's Disease prefers the parts of the body that are cooler -- the earlobes, the nose, the fingers and toes, and the eyes, though it can be anywhere on the body.  It resides in the nerves and damages them.  Where the sores are -- there is diminished or no feeling.  The devastating thing about the eyes being affected is that the blink reflex is lost.  Without blinking, the eyes dry out and foreign matter is not washed away.

This is a picture of a Belgium priest named Father Damien who spent sixteen years on the island of Molokai in Hawaii caring for the lepers who had been exiled there. He contracted Hansen's Disease and died in 1889 at the age of 49.

There is a book called "The Colony: The Harrowing True Story of the Exiles of Molokai" by John Tayman.  It is a very interesting read.  This quote from the books shows some ingenuity.

"Doctors tried training patients to blink on schedule, using a timer or some other device. The technique worked in some cases, but only if the patient was physically able. Leprosy bacilli also attack the nerve controlling eyelid muscles, creating a condition known as lagophthalmos, in which the person is unable to close the eyelids. In such cases surgeons rigged a thread of muscle from the jaw to the lid, which caused the person to blink as he chewed - doctors then handed them a pack of gum."

Now you have heard something interesting.

Left or Right?

When you pick up an infant, is it more likely for you to hold the child in your left arm or your right?  It has been found that 70-80% of women, regardless of which hand is dominant, hold babies with their left arm. 

Dr. Karl on a Triple J podcast pointed this out.  He said that with the help of physicians, mothers were studied quietly.  After examining an infant, the doctor would return the infant to the mother to the midline of her body.  Not toward the left nor the right.  The majority would take the baby and hold the child in her left arm. 

There are many different studies that I have read.  There seems to be two ideas about why this side preference might occur.  Some state that intuitively and subconsciously moms have figured out that the baby is more calm on the left side.  Before birth the baby can hear the mother's heart beating and it is a familiar, comforting sound. After birth, the baby can hear the mother's heart beat better when being held on the left side. This conclusion has many critics and is not well supported.

Many more studies believe that the left-side preference has to do with holding the baby on the side of the body that connects to the part of the brain which is dominant for processing emotions.  A mother is then better able to read the emotions of the child and react better. 

One of these studies found that mothers who cradle the baby on the right side speak higher and louder to their child than those who hold on the left.  Some mothers go back and forth between holding right and left.  Their pitch and volume went up when holding on the right.

There have also been studies about which side people prefer when hugging or kissing.  The majority of people tilt their heads to the right when kissing, and approach another person's left side when hugging.  Some of these reports think that the left-side baby cradling preference and the left-side approach to hugging are related.

There are many, many sites with this information.  Here are a few links. 

General overview
Do you kiss to the right or left?
Hugging preference
Pitch and volume differences
Left-sided baby cradling preference studies done on great apes.

Being right-handed, I always thought that I held my children on my left hip so that I could use my right hand to do things.  According to these studies, right-handers in general feel the same as I do.  And left-handers say they cradle on the left because that is the stronger arm.  It turns out it all might come down to our subconscious knowing the best way and our conscious mind coming up with a reason.

Now you have heard something interesting.

Can You Hear that Color?

Have you ever heard of synesthesia?  It is an accident of nature that would be fun to have.

Synesthesia is when two different senses are abnormally joined.  For instance, some synesthetes always see a certain color when they hear a certain musical note.  The most common form is colored numbers or letters, but any combination is possible.  There is a report of one man who tasted chocolate when he said his wife's name.  Another man claims that cucumbers taste pink.

Every synesthete experiences things uniquely.  For instance, one who sees an A major chord as purple, always sees it as purple.  But another might see that sound as yellow.

"I could never figure out why I was such a poor student at Math, until I received a 32 color pen for a present. FINALLY NUMBERS WERE THE RIGHT COLOR, 2 was yellow, 3 was green, 4 was orange, 5 was red, and so on. My teacher thought I was nutty, but when she invested in colored chalk, my Math scores SOARED... she just had to get the colors right. Oddly another student and I got into a fist-fight because he thought 3 should be blue, and 8 should be green... I won, and I made him cry, too..."

Estimates of the frequency of synesthesia range from 1 in 250,000 to 1 in 2,000.  Some famous people have this condition.  Most seem to be creative, such as musicians and artists.
Leonard Bernstein
Duke Ellington
Billy Joel
Stevie Wonder
Eddie Van Halen
Jimi Hendrix 
Frank Lloyd Wright
Victor Hugo 

Synesthetes tend to be:
Women: in the U.S., studies show that three times as many women as men have synesthesia; in the U.K., eight times as many women have been reported to have it. The reason for this difference is not known
Left-handed: synesthetes are more likely to be left-handed than the general population.
Neurologically normal: synesthetes are of normal (or possibly above average) intelligence, and standard neurological exams are normal.
In the same family: synesthesia appears to be inherited in some fashion; it seems to be a dominant trait and it may be on the X-chromosome.

The causes of synesthesia remain unknown. Some scientists have suggested that everyone is born synesthetic but that as the brain develops, the different areas become segregated.  It is not known why synesthetes retain these connections.  There might be a biological answer, because the condition tends to run in families.

For further reading, you might enjoy these books.
The Man Who Tasted Shapes by Richard E. Cytowi
Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia by Richard E. Cytowi

Now you have heard something interesting.