Posted by: Elizabeth Barilleaux | December 8, 2010

The Science Of Reindeer Games

Even if they’re not on Santa’s team, reindeer are still enchanted animals.  They’ve hung out with the wooly mammoth, the wooly rhino (yes, I said rhino) and the Neanderthals.  They weathered the warming of the ice age and evolved to handle 15 weeks of constant light followed by 8 weeks of complete darkness. They can transform their own feet into all-terrain hooves.  For six months out of the year they survive on moss.  So yeah, they’re kind of magic.

Several thousand years ago, human survival was tied up tightly with reindeer (a.k.a. caribou) existence.  Our arctic and sub-arctic ancestors followed the migrating herds, using the animals as a source of meat and fur.  Later on, humans managed to domesticate the reindeer and found they could also provide milk and transportation – and were much easier to catch and milk than a wooly rhino.  

Over time, reindeer have developed some unique features – for example, they are the only deer species where both males and females have antlers. These can develop at the rate of one inch per day, making them the fastest growing bones in the mammal kingdom. All reindeer shed and renew their antlers each year, but males lose them after breeding season (November/December).  Females hold onto their antlers until shortly after giving birth (March/April). Because all of Santa’s reindeer still have antlers in late December, it’s very likely that they are female, which explains St. Nick’s gift-delivering accuracy and efficiency.  It’s also possible that the team is a bunch of castrated males, but that seems very un-Santa like.

Reindeer also have specialized noses that warm and moisten the dry arctic air before it reaches their lungs.  Although their hearing and sight aren’t great, their sense of smell is so good they can find food buried beneath three feet of snow.

Scientists have also found that reindeer have switched off their body clocks to better handle the extreme light/dark conditions of the Arctic.  A normal mammalian body clock controls hormone cycles for sleeping and metabolism, but reindeer are more tuned in to the needs of the moment than the sun in the sky. 

One last interesting adaptation is the development of “clicking” heels.  Reindeer possess tendons that are positioned to rub over their ankle bones, creating a “clicking” sound as they walk. Biologists believe that this helps herd members keep track of each other in heavy blizzards.  Reindeer can also “adjust” their hooves to be sponge-like for extra traction on the soft, wet soil of the summer tundra or tough and sharp for digging into the winter snows. 

Aside from pulling The Sleigh, reindeer are still financially and environmentally important to folks living in the colder bits of the world like Norway, Canada and Alaska.  In these areas, thousands of reindeer are still managed in herds much like cattle in the US.    Warming earth temperatures and human encroachment, however, are taking a toll on their species.  The University of Alberta discovered in 2009 that worldwide reindeer populations have fallen by 60% within the last 30 years.  There is hope that those ever-adaptable deer will change with the times and adjust their migrations to match the earlier thaws.  Based on their track records, in fact, I think it’s likely they’ll be telling the next “intelligent species” on the planet “Yeah, it’s a real shame about those humans.  Did you hear the one about the flying sleigh….?”

Advertisements
Posted by: Elizabeth Barilleaux | November 25, 2010

The Science Of Your Stuffing

If you think you know your cornbread, think again.  I’m not talking about cholesterol or fat or sodium – on Thanksgiving that would be too cruel.  No, I’m talking about Native Americans taking a nasty, almost-inedible wild grass called teosinte  and patiently planting, selecting, cross-pollinating and harvesting over and over for thousands of years until they created the civilization-building miracle know as corn.  That’s right – Native Americans were genetic engineers minus the geeky lab coats, and the cornbread in your stuffing is their entirely artificial human invention.

The study of corn (or maize, if you prefer) is a strangely hot topic among many branches of science – anthropology, archaeology, genetics, geology, ethnobotany and molecular biology to name a few.  According to recent research,  the long, slow process of corn domestication probably took place in the lowlands of Mexico’s tropical rainforests.  Once it became a reliable, working crop (around 1500 B.C.) it spread rapidly through the Americas, forming the foundation of trade networks and literally changing the landscape of the continents as tribes cleared large areas of grassland and forest for cultivation.  Of course, you can never have explosive growth like that without an environmental disaster or two.  Based on a study by the USDA Forest Service, the rise of maize production around 500 – 1,000 years ago was a likely cause of freshwater mussel decline in the southeastern US. 

But what would an “Indian” story be without the “pilgrims?”  A lot healthier for the Indians, I’m sure, but the fact is that the Europeans arriving in the Americas saw maize for the brilliant crop it was and immediately exported it back home.  Because of corn’s ability to thrive in diverse climates, it became a global hit, and is now grown all over the world.  From the US to the Ukraine, more corn is grown – by weight – than any other grain.

In the early days, however, maize’s newfound popularity caused a major health epidemic known as pellagra.  Folks everywhere were gobbling it up by the bushel, without any thought to the consequences – I mean, it’s just food, right?  Soon afterwards, though, a nasty outbreak of skin lesions, psychosis and death followed with no discernable explanation.  Americans – particularly those in the southeast – suffered through a few hundred years, believing pellagra was caused by germs or toxins in corn.  Finally, in 1938 a group of scientists discovered that the vitamin niacin was the simple cure.  As it turns out, the original growers and consumers of maize – who did not ever suffer from pellagra – treated the grain with lime in a process called nixtamalization.   Alkalis in the lime treatment made the niacin in corn nutritionally available, which prevented disease.  Once the niacin connection was made, food processors began adding it as a nutritional supplement.  If there is any justice in nature, “pellagra” would be the Native American way of saying “so long and thanks for all the smallpox.”

So this year be sure to give thanks for all of those blessings – known and unknown – which patience, Native Americans and science have brought us.  And enjoy your stuffing.  Happy Thanksgiving!

Posted by: Elizabeth Barilleaux | November 18, 2010

The Science of Hot, Fast and Cheap Water Monitoring

Low-cost, energy efficient water monitors from NC State University (image courtesy of NCSU)

Nothing gets my nerdy bits tingling like a Really Useful Gadget.  Alex Dean and his team at North Carolina State University have designed a cost-effective water monitor  built of off-the-shelf parts that will be a tremendous help in studying coastal water conditions.  Besides measuring basic information such as salinity, temperature and clarity, the cheap monitors can be outfitted to evaluate oyster activity and provide immediate, online data.  Tracking facts like this would be a huge time and cost-saving tool for oyster farmers and environmental groups alike.  The recent oil spill in the Gulf has spread our thin environmental resources in Louisiana even thinner, but this low-cost monitoring gadget has the potential to bring us back up to speed.

According to Dr. Dean, the research team is in the proof-of-concept phase this winter through next spring.  Once testing is complete, all of the hardware and software information will be open source for easy duplication by anyone from high-school science classes to state agencies.

Posted by: Elizabeth Barilleaux | November 16, 2010

The Science Of Hibernation – The Fun Stuff

Yesterday’s blog on hibernation just sucked, and for that I apologize.  I tried too hard to fit stuff in and wound up beating all the fun right out of it.  Today I’d like to redeem myself by giving you actually interesting facts and ideas (most of it is bear-centric, which is not a particular bias of mine.  I’m guessing bears are either easier or sexier to study.)

For example, because bears pack on so much fat in such a short amount of time (30 pounds per week, which is the equivalent of 75 Krispy Kreme glazed donuts a day) their cholesterol goes through the roof.  Despite this, bears never have a problem with hardening of the arteries or gallstones.  Gallstones form in the gallbladder where bile sits and waits between meals.  While it cools its heels, the bile will become up to five times more concentrated and the cholesterol it contains can sometimes form lumps known as gallstones.    Folks who’ve had gallstones describe the pain as “stabbing and heart-attack-ish.”  Bears avoid this unpleasantness by producing ursodeoxycholic acid (UDCA), which of course has brought them much unwanted attention by gallstone-sufferers.  Although UDCA is now synthetically produced and used as a non-surgical treatment for gallstones, traditional Chinese medicine practitioners still prescribe actual bear bile, resulting in “farming” and exploitation of animals.

Another interesting feat – as a bear breaks down around 4,000 calories a day from its fat, muscle and organ tissues, it also rebuilds the organs and muscles using the nitrogen from urea.  Any starving mammal can consume its own body and build up a toxic level of urea in the process, but those clever ursines manage to reduce, recycle and reuse in the most efficient way.

Bears also manage to keep their bodies hydrated without drinking a single drop of water for over three months.  No one knows (yet) how they manage to do this, but the amount of urine collected in the kidneys drops by 95 percent.  If researchers can figure out this neat trick it could go a long way to helping folks with chronic kidney failure.

Not all animals hibernate because of the cold.  In Madagascar, the “winter” temperatures sometimes reach a chilly 860 F, but it’s the short supply of water that prompts a fat-tailed dwarf lemur  to hole up for seven months.  Either that, or it’s depressed about the size of its butt.  Since my primary impressions of lemurs are embodied in King Julien of the Disney movie, I can see it either way.

Hopefully these more lively facts have peaked your interest and cleansed your palate of yesterday’s, um, crap.  I promise to never try too hard again.

Posted by: Elizabeth Barilleaux | November 15, 2010

The Science of Hibernation

Some days, the idea of hibernation has a real appeal for me.  Taking a nice, long, cosy nap and waking up a few pounds lighter – what’s not to like?  Once I started digging around, I found that hibernation can be a lot more complicated and interesting than a simple, winter-long snooze.

Call it torpor, dormancy or – if you’re not into the whole brevity thing – carnivorean lethargy, but the basic idea is significantly slowing the metabolism.  This adaptation is nature’s clever way of coping with shortages of food, water or decent living conditions.  Scientists that study hibernation are also looking for information that will yield human benefits such as preserving organs for transplant, buying time for wounded soldiers, treating cancer and allowing long-distance space travel. 

One of the common requirements for hibernation is the storage of body fat.  Not just any fat – brown fat.  Built of smaller lipid droplets, more iron-rich mitochondria (which give it the brown color) and a higher density of capillaries, brown fat helps generate body heat while acting as a back-up source of fuel.  Larger mammals such as bears store larger amounts of fat, which allows them to sleep more deeply and for longer periods.  Black bears can rest for up to 100 days without needing to eat, pee, poop or move around.  Their core body temperatures drop by 120 F and their heart rates slow from 40-50 beats a minute down to eight.  Small mammals aren’t able to bank big masses of fat and must wake up every few days to nibble on a little something and go to the bathroom before they settle back down.  Interestingly, the body temperatures of smaller mammals can reach much colder ranges.  Ground squirrels routinely lower their abdominal temperature to 00 C, which is pretty impressive considering that blood freezes between -2 and -30 C.

So how does learning about this help us non-hibernators?  For starters, a chemical called hibernation induction trigger (HIT) that’s found in the blood of hibernating animals can help extend the life of transplant organs.  Currently, isolated organs can “survive” for about 6 hours outside of the body – HIT can prolong that for up to 18 or more.  Researchers working on methods to induce human hibernation have discovered an injectable plasma of salt and ice that quickly cools the body from 98.60 F to 500 F for several hours.  For trauma victims and wounded soldiers, this suspended animation could buy precious time to reach a medical facility.  Other researchers have successfully induced short-term hibernation  in mice simply by exposing them to air mixed with hydrogen sulfide gas.  The mixture slowed cell functions to almost total inactivity for six hours, after which the mice were revived with normal functions and no long-term damage.  This process could help people suffering from sudden, severe fevers as well as aiding and improving cancer treatments.  And finally, studies have isolated two genes that may trigger hibernation and regulate the fat-to-energy process that would allow long-term space travel.

Posted by: Elizabeth Barilleaux | November 4, 2010

The Science of the 14 Year-Old Happy Meal

Halloween is dead and gone and Thanksgiving approaches, so with one foot in the grave and one eye on the gravy boat, I’d like to talk about food decay.  A recent stink has been circulating the internet  over the experimental art of New York Photographer Sally Davies and her everlasting Happy Meal.  So many folks commented, tweeted and brought their own elderly McDonald’s food to light that a follow-up story ran earlier this month.  In fact, Davies’ project is a mere whippersnapper compared to the 14 year-old McMeal of Karen Hanrahan,  but what does all of this graceful aging add up to?  

Based on comments to the web stories, it seems the implication is that if a Happy Meal won’t break down outside your body, what’s it gonna do on the inside?  Given the 47 million people served around the world every day, the answer is pretty clear – it gets processed and excreted.  Standard McDonald fare is not a nutritional powerhouse and if that surprises you, well then I’m shocked that you’re shocked.  Long-term existence, however, does not conclusively prove that a food is loaded with preservatives, has been shellacked or is otherwise indigestible.      

My own sister freely admits to unearthing two Christmas oranges and an apple from the back of her closet while doing a little spring cleaning – fourteen months after the holiday.  All of the fruit had shriveled, but nothing had decayed.  Christmas miracles aside, examples like this illustrate that unpreserved food can avoid rot simply by being in the right place at the right time – namely a dry, lonely corner. 

Although McDonald’s doesn’t give out trade recipes, they do provide very specific ingredient lists for their food, including any added preservatives.   According to their websites, hamburger patties are filler, binder and preservative free.   Citric acid is used to keep the french fries from turning brown – like putting pineapple juice on apples – but it would not be enough to keep them from growing mold.  The buns are the most “treated” element of the Meal and include calcium peroxide as a flour bleaching agent along with calcium propionate and sodium propionate to prevent mold growth.  Mummified white-bread is not so strange, but what about the burger patty and fries?  How do they remain pristine without preservatives?

In nature, decay of any organic matter occurs as a joint venture between bacteria, moisture and warmth.  If any of these conditions don’t make it to the party, the result is a back-handed sort of preservation (much like what is happening to Keith Richards and half the population of Florida).  In the case of the long-lived McProducts, handling and cooking processes drive out a lot of moisture and then salt gets poured on like snow.  Bacteria and mold have a hard time finding any kind of foothold in that environment and thus the self-mummification begins.  As the food loses more moisture, oils become concentrated on the surface, creating a coating that essentially seals the food off from further contamination. 

Fast food will (hopefully) never be a primary source of nutrition – even if top quality ingredients go in, the end result is a greasy, salty cholesterol bullet to the heart.  A delicious bullet, but a bullet nonetheless.  At the end of the day, a fourteen year-old Happy Meal is not such a freak of nature, but I will be concerned if it asks to start driving.

Posted by: Elizabeth Barilleaux | October 28, 2010

The Science Of A Frightened Mind

Why is it so much fun to be scared?  Not truly terrified as in “oops!-my-foot-is-hovering-over-a-possibly-poisonous-snake”, but a good mental goosing in a haunted house or horror flick.  The secret lies inside the dark folds of the brain, roughly between self-control and sex. 

Almost all animals possessed of a spinal cord feel fear, but to actually enjoy it takes more than a base-model brain.  In complex vertebrates, primal emotions such as anger and fear are governed by a cranial nugget known as the amygdala.  A compelling external stimulus (such as, say, a bear interested in eating you) will light up the amygdala of most mammals, suggesting either fight (“Come on!  You can take him!”) or flight (“Run, run as fast as you can!”).  Human brains, however offer a useful third option – judgment and emotional control (“What a phony-looking bear!  Hang around and soak up some more!”) 

A study conducted by scientists at Columbia University discovered the source of this self-mastery – a control switch modulated by the rostral anterior cingulate cortex (rACC) located in the frontal lobe.  When faced with a conscious threat – something we know isn’t likely to hurt us – the rACC “dampens” the amygdala’s hysterics and allows us to think things through.   So, fantastic – you avoid peeing yourself – but why keep going back for more?

The compulsion to seek out another round of fear is a siren call from those beauties known as endorphins.  The word endorphin is a smushing together of “endogenous morphine” which literally means “morphine produced within.”  Our bodies generate endorphins in response to pain or stress (think exercise, spicy foods and orgasms).  When faced with sudden excitement, our nerves use the opiate-like analgesics to soothe the body and produce a sense of well-being.   A juicy jolt of fear ultimately ends at the same golden gate as an orgasm.  Hooray for cheap thrills – NOW it’s a party! 

Cheap thrills aside, this ability to control and even enjoy fear is a miraculous gift.  Without it, we might still be cowering in our caves somewhere – no New World, no fireworks, no moon landing, no sushi.  Rejoice this Halloween by voluntarily having the crap scared out of you.  May all your endorphin rushes be great ones.

Posted by: Elizabeth Barilleaux | October 25, 2010

The Science of Bats, Rats, Snakes and Spiders

Without a doubt, Halloween is my favorite holiday – the one time each year that people take off their masks to reveal the true, quirky self within.  Based on that inspiration, I’d like to begin my blogging series with some factoids about our animal icons of the season: bats, rats, snakes and spiders.

The alarming news – a large, flesh-eating Vampyre bat does exist.  The relieving news – it is not at all interested in you.  Chiroptera (bat) Phyllostomidae (leaf-nosed, New World) Vampyrum spectrum has a wide range of dietary inputs including frogs, snakes, insects, small birds and even other bats – but no humans.  In addition to being a stealthy and efficient hunter, it is also a “family bat.”   Mama Vampyres have one pup each year that they dote on and teach well.  Daddy Vampyres stick around too, and will often wrap up the mama and pup in his wings as they sleep.  It’s the softer side of bloodsucking that gets me every time.

Rats, on the other hand, have more of a “quantity over quality” philosophy.  One mama rat can birth 12 pups at a time and 144 babies in a single year.  Her first offspring can start breeding at two months old.  Female rats go into heat about once every four or five days, so within one year that original mama rat can have 15,000 descendants (more, if the males are real go-getter types).  Obviously, there isn’t much time to spend on education or cuddling in a rat family.

I learned the next little tidbit on summer vacation when visiting the Edisto Island Serpentarium  …Every time a snake sticks out its tongue, it is sampling the air for dozens of separate chemicals that indicate if the time has come to eat, woo or run away.  The tongue is actually a collection device that absorbs molecules onto its moist surface.  The snake then uses a spot on the upper, inside palate called the Jacobson’s organ to perform split-second data analysis. One important chemical on the Serpentes menu is adrenaline (a.k.a. epinephrine).  Adrenaline is released in mammals as part of a “fight or flight” response, which means that snakes can literally smell fear.  So think twice about poking at it–your friends might think you’re a badass, but that snake knows the real story.

And last but not least – my daughter came home from kindergarten yesterday and announced that there are exactly 1,007 types of spiders.  According to Wikipedia, there are approximately 40,000 species, so her source (or recall) was off by a few.  As an admirer of all things mechanical, I find it intriguing that spiders use hydraulic pressure to extend their eight disturbing appendages.  Jumping spiders can launch themselves 50 times their own length by quickly boosting pressure to their third or fourth pairs of legs.  Once the hydraulic system of any spider shuts down due to death, the legs curl up. Voila!  Intriguing, yes, but still not a compelling reason to keep one around as a pet.

So there you go – a peek into the not-so-well known bits of some “creepy” animal lives.  Here’s hoping that our own Halloween revelations are as thought-provoking – Happy Unmasking Day!

Categories