Fast Food: The More You See, the More You Eat!
Are fast food restaurants migrating into your neighborhood? Watch out! A new study found that kids who live near lots of fast food restaurants are more likely to be overweight or obese. Kids with healthier food choices nearby are less likely to be overweight. The study looked at data for over a million kids ages 4 to 5 and 10 to 11 in the United Kingdom, and took into account other factors such as family income and the amount of green space where kids could exercise.
Your turn! How much fast food is in your neighborhood? Use Google maps or another online mapping program to find your street, then search for restaurants nearby. Count how many of these serve fast food and how many serve other foods. Which type wins? Send your data to email@example.com or: FAST FOOD COUNT, ODYSSEY, 30 Grove Street, Suite C, Peterborough, NH 03458.
Does Migration Spread Disease?
Birds and other animals that migrate long distances may be to blame for some disease outbreaks. The West Nile Virus, which can cause flu-like symptoms in people, likely spread in North America with the help of migrating birds. (Birds don’t infect people—mosquitoes do—but birds carry the disease from one place to another.)
But migration also helps protect animals from disease, a new study shows. Monarch butterflies that migrate long distances tend to carry fewer diseases than those that don’t migrate very far. Why? Richard Hall of the University of Georgia explains that there are two reasons. One: butterflies that leave a place where a disease is spreading are less likely to get infected. Two: butterflies that are already infected may die during a long migration and then can’t spread the disease in the new location.
Hall created a computer model of a migrating population, introduced a virtual disease, and watched what happened. In the model, animals that migrated away sooner had a better chance of survival.
A Visit to the Poop Bank
Blood banks help hospitals get the blood they need to treat people who are sick or injured. The first “poop bank” in the United States, OpenBiome, does exactly the same thing. The bank prepares fecal samples (poop samples) from healthy people and sends them to hospitals.
Why would anyone need new poop? The transplant helps people with a Clostridium difficile infection. C. difficile is a type of bacterium that normally lives in your gut, but when the population grows too large, it causes very bad diarrhea or even death. Bacteria from a healthy person’s poop can fight off the C. difficile and bring the population back to normal. In fact, a 2011 study showed that a fecal transplant cured 92 percent of patients with the infection.
“People are dying, and it’s crazy because we know what the solution is,” Mark Smith, founder of OpenBiome, told the New York Times. A poop transplant may seem gross, but it saves lives!
Got a Toxic Brain? You Need Some Sleep!
A new study shows that sleep may allow your brain to clean up after itself. “It’s like a dishwasher,” says Dr. Maiken Nedergaard at the University of Rochester’s department of neurosurgery. When you’re awake and thinking and moving around, waste proteins build up between the cells in your brain. This waste could cause brain damage if it sticks around. Thankfully, the brain has a system that pumps fluid through the brain and cleans out the waste. Nedergaard and her colleagues first discovered this system last year, and they noticed that it takes a lot of energy for the brain to move all this fluid. In fact, they guessed that the brain probably couldn’t do its regular job (allowing you to think and move around) and clean up at the same time.
To test the theory, one of the researchers trained mice to fall asleep on top of a special kind of microscope that could track colored dye moving through their brains. While the mice were asleep, their brain cells actually shrank in size, and the “dishwasher” activity in the brain cranked up. The flow of fluids slowed when the mice woke up.
This research could finally explain why sleep first evolved: the brain needed to shut down the body so it could clean itself up. This is likely not the only reason that we sleep, though. Other research has shown that sleep is important for memory and learning.
Your turn! What happens to your brain when you don’t get enough sleep? Why do you think the brain can’t stay awake and clean up at the same time? Tell us your thoughts at firstname.lastname@example.org or: TOXIC BRAIN, ODYSSEY, 30 Grove Street, Suite C, Peterborough, NH 03458.
Spying on Disease
Have you ever taken antibiotics for an ear infection or another disease? Antibiotics kill bacteria, which are the tiny critters that make you sick. When you take antibiotics, you have to keep taking the pills until they are gone-- even after you start to feel better. This makes sure that the medicine kills all of the bacteria. If any are left behind, they could start to multiply again and could even learn to resist the medicine that is supposed to kill them!
Right now, it takes days or even weeks to check whether a bacterial infection is totally gone, or to test different drugs that may kill a particular infection. A newly developed tool could do the job in a few minutes!
The matchbox-sized tool can detect the motion of live bacteria. Their motion makes tiny bars inside the tool vibrate back and forth. “This method is fast and accurate,” says Giovanni Dietler of the University of Lausanne in Switzerland, who helped develop the tool. He explains that this tool would make it easier for doctors to treat a bacterial disease. It could also help researchers who are testing different antibiotics.
With the tool, doctors and researchers could quickly and easily “see” the amount of bacteria in a sample.The tool isn’t ready yet for use in doctor’s offices. Dietler and his team are continuing to test the tool on different types of bacteria to make sure it gives correct results.
How to Grow a New Liver
Thousands of people are waiting in hospitals for a liver transplant. The liver is an organ that helps clean your blood by separating good nutrients your body needs from bad toxins that get carried out in your poop or pee. If your liver stops working, you need a new one to stay alive. Right now, new livers come only from other humans. But someday, scientists may be able to grow a new liver or another organ in the lab from cells that come from your own body.
Takanori Takebe of Yokohama City University in Japan and his team recently took a big step toward this goal. The researchers started with a mix of human cells, including stem cells taken from adult human tissue. This special mix of cells, grew into tiny human livers, or “liver buds.” The liver buds are only about half the height of a Lego brick, and don’t contain all of the parts of a full human liver. But they can help clean the blood. The team transplanted the livers into mice, and showed that a group of liver buds can take over from the mouse’s normal liver to keep it alive for at least one month.
Some scientists say that it is still too early to get too excited. Over a longer period of time, the lab-grown livers could stop working or could even cause cancer in the mice. But many see the study as an important moment in science.
Takebe plans to keep improving his liver buds. Maybe one day people who need new livers will have to wait only the time it takes to grow one! Stem cell: a building block inside the human body that can grow into any type of cell
Super Snot! The discovery of friendly viruses living in your boogers
Snot, or mucus as scientists like to call it, helps protect your body from diseases. In the October 2012 “Science Scoops,” we told the story of how the sticky structure of mucus acts like armor to keep bad viruses out. But mucus is more than just armor. Inside your snot, an army of good viruses is fighting on your side. These viruses are called bacteriophages because they attack and infect bacteria. But you can call them phages for short.
The phages in your mucus aren’t a part of your body. They like mucus because it’s a perfect place to find lots of bacteria prey. When they kill bad bacteria, it helps keep you from getting sick. That’s a symbiotic relationship, when two living things interact in a way that helps both of them.
It’s one of the first examples of a direct symbiosis between phages and an animal host, says Jeremy Barr of San Diego University in California. His team studied the friendly viruses, and they were the first to realize that the phages are acting as a kind of immune system. They also found phages in mucus across the animal kingdom, from sea anemones and mice to humans.
Next time you blow your nose, think about all the extra stuff living inside your snot. It’s helping to keep you healthy!
Play for Fun . . . and you’re less likely to get hurt!
How many different sports do you play? Do you play in competitive, organized games, or just for fun? If you answered “lots of sports” and “mostly for fun,” then you may be less likely to injure yourself. Dr. Neeru Jayanthi of Loyola University is a sports medicine expert who specializes in treating tennis players. His team asked a group of young athletes, mostly tennis players, questions about how much time each week they spent playing organized or recreational games. Athletes who had suffered a sports injury reported that they spent five times more time in competitive sports than recreational. Uninjured athletes spent just 2.6 times more time in competitive sports, but on the whole, spent the same amount of time exercising as the injured players.
“Our findings suggest that more participation in a variety of unorganized sports and free play may be protective of injury, particularly among tennis players,” said Jayanthi.
It makes sense that playing different kinds of sports would make you a more well-rounded and overall fit athlete. Maybe it could help keep you safe, too!
Your turn! Do you play a sport? Interview your teammates about how much time they spend in organized games and in free play. Then note down anyone who experienced a sport injury in the past year. Do you notice any patterns? Send your research to email@example.com or: PLAY FOR FUN, ODYSSEY, 30 Grove Street, Suite C, Peterborough, NH 03458.
How Much Mercury Is in That Fish?
Fish is almost always a healthier meal choice than say, a greasy hamburger, but you have to be careful. Almost all fish contain mercury—a toxic, silvery metal that used to be common in thermometers. Pollution from power plants and natural volcanic eruptions spreads mercury into the oceans, where it makes its way up the food chain. Smaller fish typically don’t contain very much mercury, but large fish at the top of the food chain can build up large amounts of the toxin in their bodies.
That sounds simple, but do you really know what type of fish you’re eating? When you eat “tuna,” you could be munching on any one of many species, from the two-foot-long skipjack tuna found in light canned tuna, to the endangered bluefin tuna, which can reach 15 feet in length and is often served in high-end sushi.
Grocery stores and restaurants don’t always tell you which species you’re eating, or how much mercury it might contain. Jacob Lowenstein of Columbia University tested 100 samples of sushi tuna. “We found that mercury levels are linked to specific species,” said Lowenstein. His research also found that restaurant tuna steaks tended to contain more mercury than grocery store tuna. Some samples contained as much as two parts per million of mercury. That doesn’t sound like a lot, but the U.S. Environmental Protection Agency’s recommended limit is .5 parts per million. Very young children and women who are pregnant or nursing need to be especially careful. Learn more about mercury in fish here: http://www.epa.gov/mercury/advisories.htm.
But don’t let mercury scare you away from eating sushi or other fish favorites! Fish is an important part of a healthy diet. Just be sure you know what species you’re eating.
Super Seaweed-Slurping Gut Bugs
Your gut is crawling with trillions of bacteria. These tiny “bugs,” as scientists playfully call them, help break down food molecules into energy your body can use. Now, for the first time, scientists have shown that gut bacteria grabbed genes from other microbes, allowing the population to break down new foods.
Seaweed is particularly tricky to digest because the carbohydrates that make it up are more complex than the ones in land plants. Chemist Mirjam Czjzek of Pierre and Marie Curie University in France didn’t intend to study human gut bacteria at all—instead, she was trying to figure out which enzymes help bacteria in the ocean eat seaweed. To her team’s surprise, these enzymes matched ones that had been found in the guts of Japanese people.
Czjzek’s team then tested the gut populations of 13 Japanese people and 18 North Americans— five of the Japanese people had the enzyme, but zero North Americans did.
How did Japanese gut bacteria gain the same seaweed-slurping power as a marine microbe? Czjzek guesses that it has something to do with the huge amount of seaweed in the Japanese diet. Japanese soups, salads, and especially sushi rolls all contain seaweed, often, raw seaweed, which can carry marine microbes into the gut. (The effect has been dubbed the “sushi factor.”) Once the gut bacteria and ocean bacteria meet, it’s rare, but possible, for the bacteria to transfer genes.
If you don’t have super seaweed-eating bugs in your gut, don’t worry. You can still safely eat seaweed; your body just won’t break it down completely. And the next time you take a bite of sushi, or some other exotic food, think about what microbes you might be eating—maybe your gut bugs will learn a new trick!
Should Science Be Silenced?
Bird flu research could be dangerous in the wrong hands . . . but is it right to keep science secret?
Shock and outrage reverberated through the scientific community when the U.S. National Science Advisory Board for Biosecurity (NSABB) recommended that two researchers not publish certain details of their separate studies. Why? The work was too dangerous. They had each created genetically altered versions of the H5N1 virus, better known as bird flu, and these new strains had the potential to cause millions of deaths if a bioterrorist ever got hold of them or learned how to create them. “I can’t think of another pathogenic organism that is as scary as this one,” said Paul Keim of the NSABB.
Why would a scientist try to make a virus more dangerous? Ron Fouchier of the Erasmus Medical Center in the Netherlands created one of the altered viruses, and he argues that if a mutation can happen in the lab, it can happen in nature. If the research is allowed out in public, other scientists can work to better understand the virus and prepare for a possible outbreak.
Other scientists weren’t convinced, and argued that the risk of accidental escape outweighs the benefit. “This work should never have been done,” Richard Ebright of Rutgers University in New Jersey told Science.In February 2012, the World Health Organization (WHO) got together a panel of experts to independently review the studies. Each panelist had to sign a confidentiality agreement, read the paper, then turn in the paper and any notes to be destroyed. The WHO panel decided that both papers should be published in full. NSABB changed its earlier decision after reading revised versions of the papers, and the study by Yoshihiro Kawaoka of University of Wisconsin-Madison was published in Nature in May 2012.
Ron Fouchier’s paper followed the very next month in Science. Fouchier said that he was willing to risk prison time to get published—the Dutch government wanted to make up its own mind about letting the information out of the country, but Fouchier planned to go ahead and publish even if they said “no.” Thankfully for Fouchier, they said “yes”!
What do you think? Is it a good idea for scientists to try to make dangerous diseases more deadly? Should their research be locked up or freely available?
Send your thoughts to firstname.lastname@example.org or: BIRD FLU DEBATE, ODYSSEY, 30 Grove Street, Peterborough, NH 03458.
Read more famous scientific debates in ODYSSEY’s “Rage or Reason? When Scientists Feud” (October 2011 issue).
Boogers to the Rescue!
Got a cold? That gunky stuff filling up your nose is more important than you might think. Mucus, the scientific word for boogers, helps protect your body from virus attacks. In fact, you have mucus on all of the wet surfaces of your body: your nose, mouth, throat, stomach, intestines, and genitals. “Without it, we wouldn’t be able to smell, we wouldn’t be able to reproduce, and we would all be the victims of pathogens,” says Katharina Ribbeck of Massachusetts Institute of Technology (MIT).
Ribbeck and her colleagues created a gel made of purified mucins, the main ingredient of mucus. Then they coated human cells with the gel, and attacked the cells with three different viruses, including influenza A (the flu). The mucin layer acted like a suit of very sticky armor—the viruses got trapped in the gel, and didn’t infect the cells.
Of course, sometimes viruses manage to get through your mucus armor, and that’s when you get sick. Have you ever tried gargling with salt water when you have a sore throat or congestion? Ribbeck’s team may have discovered why that can help make you feel better—salt makes it even harder for viruses to get past a mucin barrier.
Someday, purified mucins may be added to ointments and other personal products to boost your body’s natural virus armor. If that ointment ever gets made, ODYSSEY hopes they name it something clever. What about, “Booger Body Butter”?
Get Your Brain in the Game
We all know that athletes have to be fast and strong. But what about smart? The famous baseball player Yogi Berra once said, “You can’t think and hit the ball at the same time.” A pro player about to take a shot in basketball or a swing in baseball may not be thinking very much, but he (or she) is using his brain in a very focused and expert manner. The player’s brain likely builds a mental model of the game, called a “forward model,” so his brain can stay one step ahead of the action.
Let’s say a soccer goalie is watching a forward approach with the ball. Her brain is already building on previous experience to predict whether the forward will kick the ball to the left or the right. Mirror neurons likely help sports players make these predictions. When you watch someone else do something, like kick a ball, your mirror neurons fire as if you were the one kicking the ball, even if you’re standing still.
Salvatore Aglioti of Sapienza University of Rome thinks that pro athletes use mirror neurons to track their opponents’ actions, and anticipate what will happen next. In a study, Aglioti asked pro basketball players, novices, and scouts to watch the body motion of a player taking a shot, without seeing if the ball went in the net. Could they figure out if it did? “Compared to novices and scouts, elite athletes were better at predicting the outcome of a shot after watching the body motion of basketball players,” Aglioti told Science News.
Can you predict a shot in basketball just from watching someone’s arms when they throw? That sounds like some super-sports smarts to me!
An End to Malaria?
Malaria doesn’t get the attention of a colossal accident like the sinking of the Titanic, but it’s a serious killer. Hundreds of thousands of people die every year from the disease. A new vaccine called RTS,S may have the power to protect people from the illness. “It has the potential to protect millions of children and save thousands of lives,” said Bill Gates. Best known for his role as CEO at Microsoft, Gates also runs a charitable foundation along with his wife, Melinda Gates. They’ve contributed millions of dollars to malaria research.
Fifteen thousand children in seven African countries are currently testing the RTS,S vaccine. So far, the data are incomplete, but early results show that the vaccine can cut the risk of contracting malaria in half, for children from five months to 17 months old. This is an exciting result, but the titanic problem of malaria is far from solved.
For babies aged six to 12 weeks, the vaccine was not as effective as researchers had hoped. Also, a year after immunization the effectiveness seems to drop. Another potential problem with the vaccine is that it has to be refrigerated—and it’s not always easy to run a refrigerator in the parts of Africa affected by the disease.
Still, this is a huge step forward in disease control. Before this, vaccines had only been developed for viral and bacterial diseases. Malaria is caused by a parasite carried by mosquitoes.
Let’s hope the final results of the trial come back positive, and that the deadly malaria parasite can be squashed once and for all!
A Cure for the Common Cold?
Got the sniffles? Eat some chicken soup and get some rest. For years, there has been no reliable cure for the common cold, or any other viral infection. The best bet was to treat the symptoms, and hope your body’s immune system could fight it off. But the human immune system has a tough time beating dangerous viral diseases such as Ebola, H1N1 influenza, or dengue fever.
DRACO to the rescue! Doubleanded RNA Activated Caspase Oligomerizer is the full mouthful of a name given to a new drug invented by Todd Rider of the Massachusetts Institute of Technology (MIT). “In theory, it should work against all viruses,” says Rider.
DRACO contains a protein produced by the immune system. This protein attaches to a type of RNA that only shows up in cells attacked by viruses. Rider’s innovative idea was to add another protein to the mix—one that causes cell apoptosis, or suicide. Basically, DRACO seeks out cells containing a virus, and then makes those cells kill themselves (along with the virus).
That’s pretty genius!
Lab trials showed that the drug could kill 15 different viruses cultured in dishes outside of a living body. Rider’s team also cured mice infected with H1N1. Next step: tests on larger animals and eventually humans. Maybe future generations will have no idea what it’s like to be sick for days with a cold!
Secret Taste Cells—All over Your Body
When you chew up a piece of candy and swallow it, you can’t taste it anymore, right? Wrong! You can’t feel a yummy sugary taste once it leaves your tongue, but taste cells inside your stomach and even your intestines sense the sweetness. These secret taste cells tell other cells to start breaking down the sugar for energy. And they have other important jobs, too. When you eat something rancid or when bacteria invade your body, bitter-sensing taste cells figure out what’s wrong and sound an alarm—then you start sneezing, throwing up, or having diarrhea to get rid of the harmful, bad-tasting stuff.
“I’ll bet you that in terms of total number of cells, there are more [taste cells] outside the mouth than inside the mouth,” Thomas Finger of the University of Colorado told Science News. He first saw these secret taste cells inside a mouse’s nose. This wasn’t just any mouse: Its taste cells had been genetically modified to glow green when exposed to light. “It was like looking at little green stars at night,” Finger said. Since first looking up that mouse’s nose, Finger has studied how taste cells inside a mouse’s nose help set off the alarm when bitter bacteria invade. Bacteria that attack mice and humans are different, though. Human noses may be next for secret taste-cell research!
Your Plastic Brain on Drugs
Alcoholics can’t shake the urge to have a drink. Where does that urge come from? Yes, it comes from the brain, but it’s often triggered by places and situations. If an alcoholic has spent a lot of time drinking in a certain club, then he (or she) will be very likely to get a craving the next time he goes there. This kind of association is well known to people who have dealt with addictions, and now a scientific study shows how it works.
Alcohol and other addictive drugs cause the brain to release dopamine. This neurotransmitter signals other areas of the brain to remember where and how an experience took place -- so there is a better chance of repeating it in the future. “People commonly think of dopamine as a happy transmitter, or a pleasure transmitter, but more accurately it’s a learning transmitter,” says Hitoshi Morikawa of the University of Texas at Austin. His research with mice showed that a period of “binge drinking,” which releases a lot of dopamine over a period of time, could actually increase the brain’s plasticity, or ability to learn. Unfortunately, this isn’t the good kind of learning! Basically, the brain is learning how to get itself drunk again and again.
Hitoshi sums it up: “There’s a growing consensus in the addiction field that addiction is a learning and memory disorder. We learn behavior associated with these drugs too well.”
Hitoshi’s hope is to find a way to “de-wire” the addicted brain and help it unlearn these dangerous associations. Good luck!Dopamine -- A type of neurotransmitter, or chemical that carries information in the brain
Feud! When Is Neuroscience Too Much Like Voodoo Magic?
What is your brain doing when you’re happy, frustrated, or jealous? Social neuroscientists want to find out. Using techniques like functional magnetic resonance imaging, (fMRI) social neuroscientists measure what parts of your brain activate in certain situations.
According to a controversial paper titled “Voodoo Correlations in Social Neuroscience,” there’s something fishy going on in many of these fMRI studies that try to match areas of the brain to thoughts and feelings. The author of the paper, Ed Vul, a Ph.D. student at Massachusetts Institute of Technology (MIT), claims that 31 out of 54 recent neuroscience papers he surveyed used flawed statistical techniques, meaning that the results these papers reported may not be trustworthy. The “voodoo” is in the reported relationships between a brain region and a behavior -- in many cases, the correlation is simply too good to be true, according to Vul.
Outraged social neuroscientists responded with a flurry of letters, blog posts, and a formal rebuttal. The details of their arguments delve into advanced statistics, but they basically want to explain why their methods are, in fact, trustworthy. Of course, these scientists want to defend their own research, but they also want to protect the integrity of their entire field. “We are worried that the whole enterprise of social neuroscience falls into disrepute,” neuroscientist Chris Frith of University College London told Nature news. Frith had authored one of the 31 critiqued papers.
Vul published a response to the rebuttal, and also changed the name of his paper to remove the word “voodoo.” The new title is “Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition.” Simply changing the name of the paper isn’t likely to end the feud, though. But thanks to Vul’s criticisms, future scientists and science writers may be more careful about the kinds of correlations they report.
Butterflies Find a Cure
When you’re feeling sick, your mom or dad gets you medicine. But what does a butterfly do? The monarch butterfly, famous for its long migration and bright orange and black wings, seeks out a cure for its caterpillars by laying eggs on medicinal plants.
Wait, you might be saying, don’t butterflies only eat milkweed? You’re right, but the species of milkweed matters. These plants contain toxic chemicals called cardenolides, and tropical milkweed has more toxins than swamp milkweed. Monarchs are not harmed when they eat the toxins; instead, they build up the poison inside their bodies, making them toxic, too!
But even a toxic insect has problems. The parasite Ophryocystis elektroscirrha infects monarch caterpillars. The infection lasts through the transformation to butterflies, and can be passed on to future young. The more toxic a caterpillar or butterfly is, the better it will be at fighting off the parasite. So it’s a good idea for caterpillars to eat the tropical milkweed instead of swamp milkweed.
But caterpillars don’t know what’s good for them. Jaap de Roode, who heads a monarch butterfly lab at Emory University in Georgia, tried giving the caterpillars a choice between tropical and swamp milkweed, and the baby bugs showed no preference.
Of course, Mom knows best. Female monarchs infected with the parasite preferred to lay their eggs on tropical milkweed, while uninfected females didn’t care. “These very small animals have the ability to make a distinction between plants that will be good for their offspring and plants that will be bad for their offspring,” says de Roode. “Somehow, they know that they are infected, and they know what to do about it.” Pretty amazing! Those cured caterpillars will be all ready to fly to Mexico.
Mirror, mirror, on the wall, who’s the healthiest of them all?
Take a look in this mirror. It’s looking back at you, and measuring your pulse! A camera in the corner senses your face, and a computer tracks tiny differences in brightness as blood moves beneath your skin. Your pulse then displays as a number at the bottom of the mirror.
“You can imagine every day when you look into the mirror, not only do you see your physical appearance, you also get a snapshot of your health,” says Ming-Zher Poh, a graduate student at the Massachusetts Institute of Technology (MIT) who designed the system. Eventually, Poh plans to add measurements of respiration, blood-oxygen levels, and blood pressure to the device.
Using a camera to measure vital signs isn’t completely new, but no one’s done it before with an ordinary, low-resolution webcam. Plus, Poh developed new techniques for tracking faces -- the system can follow up to three people at once, even if they’re moving around slightly.
Eventually, Poh’s system could be installed on a cell phone, laptop computer, or any other device with a video camera. High-risk patients could be monitored continuously throughout the day, and regular people could keep daily records of their health, which their doctor could also access through the Internet.
Here’s my question: Will the camera give out stickers after each visit?
Microgrippers Invade. . .Your Body!
A six-armed metal spider, tiny as a fleck of dust, travels through tubes and tissue to its destination: a patch of liver cells. Snap! Its arms close around the cells, and it heads back to waiting doctors to deliver the precious cargo.
Someday, surgical tests may no longer require long needles or incisions. Tiny machines could navigate the body, targeting specific cells or dropping medicines in just the right location. The story I just told about the metal spider hasn’t yet happened in a living body, but it’s been simulated at David Gracias’ lab at Johns Hopkins University in Baltimore.
Typical tiny medical machines run on bulky batteries or drag pesky wires behind them. Gracias’ goal was to run a microgripper without any power source. “It is hard to make something autonomous if you need batteries. You have to recharge the batteries, and making small batteries is very difficult,” Gracias told the National Institute of Biomedical Imaging and Bioengineering (NIBIB).
How do you make something run without power? Layers and magnets. The microgripper is shaped like a six-legged metal spider; the legs are positioned just right, so they want to snap shut. The only thing keeping them open is a thin layer of polymers, which are the main ingredient of most plastics, but also occur naturally in the body. Natural biopolymers break down when certain enzymes, or proteins designed to cause chemical reactions, come close. All Gracias has to do is introduce the right enzyme at the right time and place, and the polymers holding the arms open will dissolve, letting the machine snap shut. Another specially designed layer of polymers triggered by a different enzyme opens the machine again.
Where do the magnets come in? That’s how Gracias steers his microgrippers. In a lab test, his team used a magnetic wand to successfully pilot the microgripper through fake innards to reach a piece of bird liver tissue, simulating a real liver biopsy where doctors need a sample of liver cells for testing. “We were also able to navigate the microgrippers through tight corners, and pick up a bead to drop it off deep inside a plastic model of a liver,” team member Noy Bassik says.
Of course livers are not the only destination for microgrippers and micromachines. Gracias’ team hopes to shrink them even more so they could grab a single blood or cancer cell.
Your turn! Imagine you’re a microgripper navigating through the body. Tell a short story from your perspective as you track down a cancer cell and grab it. Send your story (500 words or less) to email@example.com or mail it to: MISSION: MICROGRIPPER, ODYSSEY, 30 Grove Street, Peterborough, NH 03458.
You can see the microgripper at work at: http://www.jhu.edu/news_info/news/home09/jan09/gracias.html
Your Skin Can Hear!
You see with your eyes and hear with your ears, right? Not exactly. The body’s senses work together in mysterious ways. A 1976 study discovered that seeing a person’s mouth move affects what we hear them say. When subjects saw one syllable on a person’s lips and heard a different one in their ears, they usually report “hearing” the sound they saw or a different sound somewhere in between the two. Well, now the skin wants to get in on the hearing action: Puffs of air on the skin can change what we think we hear.
Try saying the sound “ba” with your hand in front of your mouth. Now say “pa.” Do you feel the big puff of air when you say the “p”? That’s called an aspirated sound. You should feel the same difference between the sounds “da” and “ta,” or “ga” and “ka.” Go ahead; try it! In a recent study led by Bryan Gick of the University of British Columbia in Canada, blindfolded subjects had to report what sounds they heard: ba, da, pa, or ta. While the participants listened to a voice speak these sounds, a machine sometimes blew puffs of air onto their hands, necks, or ears. Most of the participants didn’t even notice the puffs of air, but it still affected their hearing!
When there was no puff alongside any of the sounds, participants made a lot of mistakes. When the aspirated sounds came along with a puff (to any part of the body), accuracy improved by 10–20 percent. But when the puff was played with an unaspirated sound like “ba,” some subjects actually reported hearing “pa” instead. “Our skin is doing the hearing for us,” Dr. Gick told The New York Times. “People are picking up on this information that they don’t know they are using.” And it doesn’t seem to matter what part of the skin feels a puff -- Gick reports that even feeling a puff on your ankle can make “p,” “t,” and “k” easier to hear. Gick hopes to use this discovery to help create better hearing aids or devices for people who work in noisy environments.
So hearing isn’t all about the ears -- the eyes and skin help out, too. Gick puts it this way: “We are these fantastic perception machines that take in all the information available to us and integrate it seamlessly.”
Perception -- Sensing
Thanks to Your Twin Brother
As boys develop in the womb, they produce a lot of testosterone, the hormone that makes them develop male characteristics. But how do these doses of hormones affect a girl twin who happens to be in the womb at the same time? She doesn’t need testosterone! It turns out that these extra boy hormones do influence a girl twin’s development and perhaps even her personality later in life. These girls may be more aggressive, take more risks, and score more like boys on language and spatial reasoning tests, according to various studies by psychologists in Europe and the United States. Generally, boys tend to be better at spatial reasoning, and girls better at language. Remember, these differences don’t apply to every individual boy or girl! If you took two kids out of your class at school, it would be impossible to guess how they would act or score on a test, based on gender alone. But if you tested everyone in the whole school, you would start to see some of these differences.
You may know that girls are much more likely than boys to develop eating disorders. Most people blame this on a culture that urges girls to be skinny. But some scientists wonder if biology plays a role. A recent study led by Karen Klump of Michigan State University in East Lansing looked at data from several hundred twin pairs, girl-boy, girl-girl, and boy-boy. The girls who shared the womb with boy twins were much less likely to have eating disorders than the girls who shared the space with girl twins! So, that twin brother was good for something, right?
Boys who share the womb with girl twins, however, don’t turn out more “girly” than other boys. Why? Girls don’t need any extra doses of estrogen, the female hormone, to develop normally. In fact, estrogen is only present at trace levels in a girl during gestation. If a boy embryo doesn’t get enough testosterone, however, he can develop female characteristics. That’s because girls are the “default” state of a human baby! The fetus needs that extra testosterone to become male.
Fat + Sugar = Cheap
Fast foods and junks foods aren’t just terrible for your body; they’re tasty and easy to get. Add to that the fact that they’re cheap, and you’ve got the American obesity problem. Adam Drewnowski of the University of Washington was one of the first to study the link between how much money Americans have and how overweight they are. His 2005 study, “Food Choices and Diet Costs: An Economic Analysis,” published in the Journal of Nutrition, showed that the highest rates of obesity are found in low-income households. Those oh-so-tasty but unhealthy ingredients -- added sugars and fats -- deliver the most energy for the least amount of money. Drewnowski pointed out that just educating people about eating healthy might not be enough. What if they can’t afford it?
“There are three things needed in order to eat healthy: knowledge, money, and time,” Drewnowski said. In 2009, he published the results of a study tracking what 164 adults in the Seattle, Washington, area ate for 15 months. The healthiest eaters were college-educated women with enough money to afford things like organic soybeans. Their diets were rich in costly nutrients, vitamins, and minerals. In contrast, participants with less money and less education ate energy-dense diets that didn’t provide as much nutrition. “As food prices go up, the natural tendency is to fill up on inexpensive sweets and fats,” said Drewnowski. “We need to make affordable nutrient-rich foods available to every American household.”
Got any ideas? How could your family eat healthier without spending more money? Send your ideas (or recipes!) to firstname.lastname@example.org or write to: HEALTHY ON THE CHEAP, ODYSSEY, 30 Grove Street, Suite C, Peterborough, NH 03458.
Watch out for Hot Ice
An unsuspecting 45-year-old man from England sat down to a meal of seemingly scrumptious grouper fish while on vacation in Antigua. He soon regretted that meal. At first, the bad fish made him horribly sick to his stomach. Two days later, the poison went to his brain. Hot tea seemed freezing cold while ice water seemed to scald his tongue. This poor tourist got ciguatera poisoning, a form of food poisoning that is actually fairly common. But not every victim suffers paradoxical dysaesthesia, the fancy name for getting hot and cold mixed up. Most reef fish, including the grouper, barracuda, and snapper, are safe to eat, but every once in a while, these fish can contain ciguatoxin, which causes a huge variety of miserable and strange symptoms. A surgeon aboard the famous explorer Captain James Cook’s ship described a case of ciguatera poisoning back in 1774. He wrote that several men had imaginary feelings of loose teeth, pain in their arms and legs, and burning sensations in their faces. Usually, these kinds of symptoms go away within a few days or weeks, and ciguatera poisoning is not deadly.
The poor Englishman who thought hot was cold and cold was hot didn’t get completely better for ten months after eating bad fish. Peter Bain, a researcher at Imperial College in London, described this unusual case in the October 2007 issue of Practical Neurology.
You wake up one morning with blank spots in your brain. Something, or someone, is erasing your memories! Is this a science fiction nightmare, or a scientific breakthrough?
Science is still far away from erasing specific memories, but a team led by Roberto Malinow of Cold Spring Harbor Laboratory in New York found a certain molecule, glutamate receptor 1 (GluR1), that seems to be partially responsible for collecting strong, emotional memories. You probably remember that time you broke your arm, or got stung by a bee, or won a raffle, but do you remember what you ate for breakfast the first day of February last year? Emotional experiences cause your body to produce the stress hormone norepinephrine, which helps make lasting memories.
The new research discovered how norepinephrine helps attach a small molecule called a phosphate group to GluR1. The phosphate group helps GluR1 molecules move to the surface of a nerve cell faster, where they send and receive signals from other nerve cells. If those phosphate groups don’t attach, the GluR1 won’t be able to do its job.
It’s scary to think about messing with memory, but some people wish they could forget scary events. “In post-traumatic stress disorder, where you have too much emotionally charged memory, this [GluR1] could provide a molecular target for possible treatments,” Malinow told Science News.
If you’ve read Lois Lowry’s famous science fiction book The Giver, you may remember that it’s about a society where bad memories are kept by one special person, and no one else has to think about those things.
What do you think? If science finds a way to do it, would you want to erase your painful memories? How would the ability to erase memory change our lives?
Email your response to email@example.com or write to MIND TRICKS, ODYSSEY, 30 Grove Street, Suite C, Peterborough, NH 03458.
News to Zap Your Brain!
A fifty-year-old, obese man had tried absolutely everything short of surgery to lose weight. Finally, he decided to have electrodes implanted inside his brain. All he had to do was hit a button, and zap!, his hunger was supposed to disappear.
This procedure is called deep brain stimulation, and has been used to treat Parkinson’s disease. It’s not a normal treatment for obesity, but an almond-sized area of the brain called the hypothalamus helps control hunger. So neuroscientists thought they could use this procedure to help control his appetite too. While a team of neuroscientists led by Andres Lozano, of the Toronto Western Hospital in Ontario, Canada, were trying to identify the best spot on the hypothalamus to place the electrodes, they stumbled upon something amazing. When they stimulated a certain spot, the patient vividly experienced a memory from about thirty years before! The more electrical voltage they applied, the clearer the memory became. After three weeks of continuous stimulation, the patient took learning tests with and without stimulation. With the electrodes switched on, he scored three times higher. The team is now testing deep brain stimulation on patients with Alzheimer’s, a disease that affects memory.
Did deep brain stimulation cure the man’s obesity? Nope. The procedure worked -- with the electrodes turned on, the man’s appetite disappeared -- but he had the button to control those electrodes, and he turned them off at night, then ate to his heart’s content!
Electrodes -- Tiny objects that emit electric charges
Parkinson's Disease -- A progressive nervous system disease that causes muscle tremors, movement difficulty, and weakness
Dirty Diaper Discovery
Did you know that the number of all the human cells that make up your body is less than the number of bacteria cells that live in it? In fact, the bacteria outnumber your cells ten to one! And most of these little creatures live in your intestines, commonly called your gut.
Before birth, a baby’s gut is squeaky clean. But within just a few days, bacteria start colonizing it causing diapers to get smelly. Those poop-filled diapers are treasure troves to geneticist Chana Palmer and her colleagues at Stanford University. They spent a year poking around in fourteen babies’ diapers looking for clues as to how our teeming zoo of gut bacteria develops.
“The infant’s gut is an exciting and rapidly evolving place,” Palmer told Scientific American magazine. “Populations [of bacteria in the gut] are quite unstable over the first few months, but by a year of age they resemble each other and also resemble adult guts.” As a new baby learns to say ga-ga and roll over, his or her gut is filling up with Bacteroides, Clostridium, Ruminococcus, and other microbes. These bacteria come from contact with the baby’s mother and other family members, and are necessary for a healthy digestive system.
Palmer’s study included a pair of fraternal twins, delivered by caesarean section. The twins’ bacteria took longer to develop (perhaps because they didn’t come in direct contact with their mother’s bacteria during birth). But when the twins’ guts finally began to flourish, their poop was more similar than any other poop in the study, suggesting that genetics plays a role in what little creatures come to dwell in our intestines.
Cesarean section -- A surgical incision through the abdominal wall and uterus, performed to deliver a baby
Your heart pumps as much as five quarts of blood per minute through the network of tiny veins in your body. What if that energy could be used to run machines? If you saw the movie The Matrix, you may be imagining rows of humans hooked up like batteries to provide power for robots. But never fear -- in nanotechnology, the robots are very tiny and they’re helping you!
Zhong Lin Wang and his colleagues at the Georgia Institute of Technology have developed a new nanogenerator, a power producing chip that could be used to run many different kinds of tiny technology. Nano is a prefix that means one-billionth of a unit in size. Because the nanogenerator is so small, it can’t be made with regular tools. The different parts have to be grown using chemistry!
Wang’s nanogenerator is made of a bunch of miniscule vertical nanowires that flex against a zig-zag shaped electrode in response to any movement, including the flow of blood. When the nanowires are kept in motion, the nanogenerator produces a small but continuous flow of electricity.
“If you had a device like this in your shoes when you walked, you would be able to generate your own small current to power small electronics,” says Wang.
What’s wrong with regular batteries? Most of them are too big for nanotechnology, and the chemicals that make up batteries are dangerous. Wang’s nanogenerator uses zinc oxide, which is non-toxic and compatible with the body, so it could be placed inside your body along with a device to measure your blood pressure. Maybe someday nanobots, itty-bitty robots that are still mostly science fiction, will patrol your bloodstream and destroy diseases using power generated entirely by the constant pumping of your heart.
Electrode -- A component in an electric circuit at which current is transferred between ordinary metal conductors and a gas or electrolyte (a liquid that conducts electricity because it contains charged particles either in solution or in a molten compound).
What Color Is Your Blood?
Red, right? That is, of course, unless you’re a Vulcan like Mr. Spock aboard the Starship Enterprise on Star Trek. But doctors in Canada recently got a “Spock shock” when a patient they were operating on started oozing dark green blood! Yes, for real!
According to Science News and other science news sources, a 42-year-old man was admitted to St. Paul’s Hospital in Vancouver after he developed a dangerous condition in his legs -- a result of falling asleep in a sitting position. When lead surgeon Alana Flexman and her team made an incision to relieve pressure and swelling, caused by the man’s condition, they discovered dark-green blood coursing through his arteries. Flexman immediately sent the man’s blood for analysis.
Is the patient really a Vulcan? Hardly. You see, he had been taking a large dose of sumatriptan, a special headache medicine, that caused a rare condition called sulfhemoglobinaemia. The blood turns dark green because a sulfur atom gets incorporated into the oxygen-carrying compound, hemoglobin, in red blood cells.
Normally, the green color goes away once the red blood cells regenerate. In this case, the patient had surgery before that happened. Five weeks after he stopped taking the sumatriptan, he became, once again, a red-blooded Canadian.
Martians Sleep Light!
Having trouble sleeping at night? Well, an experiment designed to help astronauts live on Mars could help insomniacs on Earth.
Charles Czeisler of the Division of Sleep Medicine at Brigham and Women's Hospital and Harvard medical school in Boston, and his colleagues found that two 45-minute exposures to bright light in the evening could help people adapt to the slightly longer day (about 40 minutes longer) on Mars. That slight difference is long enough to throw most people into a state of jet lag, which, Czeisler says, interferes with the ability to learn, remember things, react quickly and to sleep.
In the study, 12 healthy volunteers aged 22 to 33 slept for eight-hours, then stayed awake for 16-hours in their homes for at least three weeks. The researchers found a wider-than-expected variation in an internal system the human body uses to keep track of days and nights. When the researchers took blood from the volunteers every hour, they found those people with the shorter internal clock released the sleep hormone melatonin four to five hours before their usual bedtimes, while those with unusually long internal days did not release melatonin until about an hour before bedtime.
So Czeisler's team tested the volunteers in a similar way, using two 45-minute exposures to bright light for 30 days. That done, the volunteers successfully adjusted to the Martian-length day, Czeisler said.
“The results have powerful implications for the treatment of circadian rhythm sleep disorders, including shift work disorder and advanced sleep phase disorder,” Czeisler told Reuters. This could mean that light therapy might help people whose insomnia is caused by having a long- or shorter-than-normal internal body clock, Czeisler said.
Bad to the Bone?
Actually, researchers have found that obesity is bad for the bone. As reported in The Journal of Clinical Endocrinology and Metabolism (May 2007), a new studyby Hong-Wen Deng (University of Missouri-Kansas City) and colleagues found that increasing body fat mass decreases bone mass, for people of similar weight.
The findings fly in the face of a general belief that obesity increases bone mass and is therefore good for bone health. In fact, the purpose of the recent study was to reevaluate the relationship between obesity and bone disease, taking into account the effects of total body weight on bone mass in more than 6,400 healthy adults.
Deng and his team say their finding is important because proper thinking may lead now to proper intervention or treatments. The study also reaffirms the benefits of being fit. In other words, it’s true the bigger you are, the harder you fall -- and the harder it will be to get back up. So think “lean, mean, healthy machine.” !
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