I stayed up until after midnight watching NASA TV’s coverage of Curiosity’s landing on the red planet. It was absolutely amazing and I hope kids everywhere will be inspired to study about space, planets and science in general. If you haven’t visited NASA.gov, you’re missing out on an amazing array of NASA websites dedicated to space and our very own Earth.
Here’s the Mars Science Laboratory website, if you want to follow Curiosity’s mission!
In 1348, Pope Clement VI’s physician wrote the following as the “Black Death” hit Avignon: “It was so contagious, especially that accompanied by spitting of blood, that not only by staying together, but even by looking at one another people caught it…The father did not visit his son, nor the son the father. Charity was dead and hope was crushed.” (From Deadly Companions by Dorothy H. Crawford)
Scientists have long suspected that the bacterium Yersinia pestis,which causes bubonic plague, caused the Black Death that killed over 30% of Europe’s population in 1347 and continued to burn through Europe for the next three hundred years. Two teams of scientists reported this week that not only was Yersinia pestis definitely the microbe that caused the Black Death, but that bubonic plague has its roots in China, where it has lived in fleas in the wild rodent populations for thousands of years. Humans are an accidental host of this deadly bacterium, but in three major waves it decimated the populations of Europe, Asia and Africa, causing the most dramatic fall in population ever recorded.
Y. pestis is carried by fleas, who are made ravenous by the bacteria and jump from rodent (often rats) to rodent looking for warm blood and injecting thousands of bacteria with each bite. As rats die, the fleas sense the cooling blood and jump to new victims. If the victim is human, they will probably be infected with bubonic plague and, if untreated with antibiotics (which they didn’t have during the middle ages), stand a pretty good chance of dying. If the infection goes to the victim’s lungs and they infect someone else by coughing on them, that person is as good as dead.
Bubonic plague eventually died out in Europe, but not before infected rats stowed away on ships traveling to the United States in the 1890s, where they arrived in San Francisco and quickly infected the squirrel population. Over 50 kinds of rodents in the Western U.S., Canada and Mexico are potential hosts for Y. pestisis and the bacteria is still surviving in these populations, from California to Colorado. Fortunately, as long as the disease stays in wild rodents and away from urban rat populations, it probably won’t cause many cases of plague in the U.S.A. (there were only 15 in 2006.) We’re lucky to live in the age of antibiotics, which can treat most cases of plague today.
What should you do if you don’t want to catch the “Black Death?” Avoid wild rodents like the plague.
“Infectious agents — whether viruses or microbes — are constantly testing their environment for new host species to survive.” Beatrice Hahn, University of Alabama
Tiny organisms that can make us sick, known as microbes, are magicians at both changing and exchanging ways to survive in animal (and human) bodies. We have get new flu shots each year because H. influenzae, the flu virus, is constantly mutating. Salmonella enteriditis bacteria, which can infect eggs have received “injections” of genetic information from other bacterial species, which makes them more toxic to humans. Bacteria mutate often and trade antibiotic resistance like kids trade Pokemon cards.
One trick that makes microbes especially dangerous to us is their ability to occasionally jump from animal to animal, or animal to human. Our immune systems can often fight off infections that have been circulating through the human population over time, because we “recognize” the microbes trying to infect us. However, when a microbe jumps from animal to human, our bodies often don’t have the ability to recognize it or fight it off. (Researchers speculate that the 1918 Flu virus that killed over 40 million people may have been passed from birds to pigs, and then to humans.)
It is often even easier for a microbe to jump to a closely related species, like from chimpanzee to human, since we are so similar. To illustrate this idea, imagine a bacteria that usually infects circles. Chances are, it would be more likely to recognize and infect an oval than to infect a square. For a microbe to go from a chimpanzee to a human would be like going from circle to oval, while a jump from bird to human would be more like jumping from circle to square.
In the news this week, I learned that researchers have been racing to be the first to discover which of our primate relatives passed the parasite Plasmodium falciparum, which causes malaria, to the human population. This race comes on the heels of a paper showing that H.I.V. probably originated in monkeys over 32,000 years ago before being passed to chimpanzees, and then on to humans. A scientist named Beatrice Hahn, from the University of Alabama, along with many collaborators, won the race and demonstrated that the malaria parasite jumped from western gorillas to humans in a single leap, probably between 5,000 and 300,000 years ago.
We don’t worry much about malaria in the United States, but P. falciparum is a killer. According to the World Health Organization, or WHO ,”In 2008, there were 247 million cases of malaria and nearly one million deaths – mostly among children living in Africa. In Africa a child dies every 45 seconds of Malaria, the disease accounts for 20% of all childhood deaths.” If malaria has been around for over 5,000 years, we can only imaging how many people it has killed.
Hopefully, these findings will allow researchers to compare the original parasite, found in gorillas, to the modified one, found in humans and discover new avenues for preventing and curing the disease it causes. Maybe researchers will also gain more insight into how microbes jump from one animal to another, allowing us to prevent, or quickly halt diseases like malaria, H.I.V., or the 1928 flu before they become pandemics and kill millions of people.
More than half a billion eggs were recalled after Salmonella sickened over 1600 people (according to the Center for Disease Control, or CDC in September.) That’s a lot of eggs, and a lot of sick people.
What is this nasty bacteria that makes us wonder whether we should let our kids eat raw chocolate chip cookie dough, even as we sneak several spoonfuls when they’re not looking?
Salmonella enterocolitis is one of the most common types of food poisoning and is caused by the bacteria Salmonella Enteriditis. You can get a Salmonella infection by swallowing food or water that is contaminated with the salmonella bacteria. Often, the culprit is surface contamination from raw chicken and raw or undercooked eggs. In most people, it causes diarrhea, fever and abdominal cramping, but young children and those with weakened immune systems are at greater risk of dehydration and more serious infections.
Why don’t they just wash the eggs better? Salmonella bacteria live in the intestinal tracts of animals and birds and can infect the ovaries of healthy-looking chickens. This allows bacteria to infect the eggs even before the shell is formed and voila- you have a pathogen that can’t be washed off of the egg because it’s inside. Salmonella bacteria are often found in the “white” of an egg, although they can migrate to the yolk as the raw egg sits in your refrigerator. Organic and free range chickens have less disease than factory-”farm” raised chickens, partly because of healthier diets and less crowding. Cooking eggs until the yolk is solid kills Salmonella bacteria.
How can you make your cookie dough and eat it too? Buy pasteurized eggs (you can find them at most grocery stores) that have been heat-treated to kill bacteria, but are still essentially raw for all cooking and baking purposes.
Also, remember to wash cutting boards you’ve cut meat on with soap and water before cutting anything else on them, or just have separate cutting boards for meat. Don’t forget to wash your hands after handling raw eggs! Pet food and reptiles can also harbor salmonella bacteria, so have your kids wash their hand after handling either!
Bacteria are everywhere. Some keep you healthy and some make you sick, but making good decisions in the kitchen can keep you and your family from being affected by food-born illness!
Did you know that we have ten times more microbes in our bodies than human cells? It may sound gross, but these microbes are often more friend than foe and keep us healthy in return for a little space to call their own.
There was a fantastic article in yesterday’s Science Times about microbiomes- what scientists call the collection of microorganisms colonizing our bodies. The study of microbiomes has intensified in recent years and scientists are trying to catalog some of the bacteria we carry.
I eat yogurt filled with healthy, or beneficial, bacteria on a daily basis to keep a healthy population of these little helpers living in my gut. This keeps the bad bacteria from finding a place to take hold. A more extreme version of this was mentioned in the Science Times article, where a woman dying of an intestinal infection caused by pathogenic, or bad bacteria was saved when bacteria from her husband’s intestines was introduced into her large intestine. Within hours, the good bacteria had “kicked” the bad bacteria out, taking over residence.
I also learned that babies born by C-section (like my three kids) are more prone to skin infections and asthma, possibly due to the fact that coming from the sterile amniotic sac, they are colonized by bacteria from adults’ skin rather than that bacteria from their mother’s birth canal. In fact, people with asthma have a different set of lung microbes than healthy people and obese people have a different set of bacteria in their guts than people of normal weight.
You’ve heard that kids on farms and are exposed to dirt have healthier immune systems than city kids? It’s not the dirt itself, but the microbes in the dirt giving them their immune systems a boost.
There are years of hard work in the lab ahead of scientists to validate their beliefs that beneficial bacteria may one day be a weapon in the arsenal against infectious disease, but in the meantime, I plan to keep eating my yogurt and letting my kids play in the dirt.
This morning, Twitter led me to a great website filled with science news for kids. Check it out at http://sciencenewsforkids.com/.
The Society for Science and the public, who sponsors the site, is having a contest for kids in grades 6-12 where they can enter their own podcast talking about what they’ve learned about science from the website. Go here for more details.
It sounds like a great way to keep your kids reading about science this summer!
Whale hunting has been in the new a lot recently, but it now appears that the biggest threat to these intelligent, majestic animals is no longer whalers’ harpoons.
I read this morning in the Star Tribune that “Sperm whales, feeding even in the most remote reaches of Earth’s oceans, have built up stunningly high levels of toxic and heavy metals.” Most of these contaminants have been introduced into the ocean by humans of course. The article goes on to talk about how our food supply is being threatened by our poisoned oceans and that seafood is a primary source of protein for over 1 billion people. Do you eat fish?
Apparently, high concentrations of these poisons collect in these whales because they are at the top of the food chain. That means they eat fish and squid that have eaten smaller animals, which have eaten yet smaller animals and plants and so on. Humans are also at the top of the food chain, and although we don’t only eat contaminated fish, we eat many other plants and animals that are exposed to heavy metals, pesticides and herbicides. Both whales and humans nurse their young, passing contaminants from mother to baby. (That beautiful piece of wild salmon may not be as pristine as you’ve convinced yourself that it is. Like it or not, our bodies are full of toxins too.)
What’s happening to the whales is happening to us. The difference is that the whales are not the ones polluting the world.
Look at the Gulf. Looks at our sick oceans. Go read “The Lorax.”
We have to save the whales to save ourselves.
I just got this email from the Science Museum of Minnesota and thought I’d share it with you. It sounds like a great way to spend Father’s Day!
Father’s Day – Sunday, June 20, 2010 – 12 p.m. to 5 p.m.
at the Science Museum of Minnesota
Make: Day at the Science Museum is this Father’s Day—Sunday, June 20, 2010. Mark your calendars for the chance to meet with an astounding group of local engineers, artists, tinkerers, and inventors. They’ve been hard at work, and now they want to share their DIY creations with you.
Presentations to see, hear, and interact with include:
- A 3D Printer that makes plastic models from computer designs right before your eyes
- A potential Guinness World Record-breaking attempt using kinetic gadgets
- Musical performances by experimental musicians using custom-built instruments
- A bicycle ride across a suspended cable
- Plus a whole lot more!
You’ll have the opportunity to meet with the makers, ask them about their inventions, and learn about ways that you can get involved with local making communities. Presentations will be located throughout the museum’s exhibit galleries. The event is included with regular museum admission.
Dads get in free to Make: Day!
Make: Day is a great way to celebrate Father’s Day with the whole family. With all the amazing DIY presentations, there’s sure to be something for everyone. And don’t forget to take advantage of the incredible opportunity for dads to get in free with the Make: Day Father’s Day coupon. Just print it out and present it at the box office along with any full-price ticket purchase. The free admission is good for any exhibit combination, including the Omnitheater and The Dead Sea Scrolls. So bring your DIY (or not-so-DIY) dad down and see what’s being made!
In today’s paper, I was disgusted to read that two school-age children, a toddler and a 70-year old man were victims of an E.coli outbreak this week caused by raw milk from a Minnesota dairy. The toddler is currently hospitalized with a serious condition related to the infection (hemolytic uremic syndrome) which can cause kidney failure and death. These are unnecessary illnesses and people are putting themselves and their children at risk by drinking raw milk.
Pasteurization is the process of heating up food to kill any bacteria it might contain. Louis Pasteur first tested the process in 1864 and it is perfectly safe. However, some people who drink raw milk feel that beneficial proteins and bacteria are destroyed during the heating process.
According to the Health Department, several dozen people are sickened by raw milk every year in Minnesota. Unpasteurized milk can contain the live pathogens, or bad bacteria, E. coli, Salmonella and Campylobacter. Most people are careful handling and cooking meat to avoid the very same pathogens. Why they wouldn’t mind drinking them is a mystery to me.
Beneficial, or “good” bacteria can be found in most yogurt and many companies now add beneficial bacteria to other dairy items, including pasteurized milk. I suspect that many of milk’s other beneficial heat-sensitive proteins can be found in other, safe foods as well. Even raw milk cheese made correctly is safer than raw milk, because it contains other microbes that inhibit the growth of pathogens.
Maybe people don’t realize it, but giving their child a glass of raw milk is as risky as feeding them a raw hamburger. I’m glad to hear the state is cracking down.
When I told my husband that scientists at the J.Craig Venter Institute had assembled a funtioning bacterium from bottles of chemicals, he said exactly what I was thinking. “It’s like The Stand.” Even if you’re not a Stephen King fan, you’ve probably heard of his novel where a genetically engineered strain of the flu virus wipes out almost every human on earth.
USA Today, on the other hand, said “The long-anticipated advance, reported in the journal Science, is a $40 million milestone in the nascent field of “synthetic biology” and points towards a future of designer microbes manufacturing fuels, chemicals and materials.”
The news that a synthetic bacterium has been created comes as no surprise to most scientists. Even when I worked in a lab ten years ago, we cut and pasted bacterial DNA together on a regular basis. We also synthesized relatively short pieces of DNA by pushing buttons on a machine. The technology has vastly improved since then, and entire bacterial genomes have been sequenced. Scientists know exactly what it takes to make a functioning bacterial cell.
Some good and bad uses for synthetic biology immediately spring to mind:
Good things: Scientists may be able to design bacteria that specifically target certain areas of the human bodies, so that the bacteria could colonize those areas (say, the intestine) and produce and deliver drugs to specific organs without causing harm. You could even turn drug delivery on and off by putting “inducible promoters” which are basically on/off switches, in front of the genes for drug production. You could possibly use the technology to deliver chemotherapy directly to tumors too, if you could create bacteria that recognize and bind to certain proteins produced by tumor cells.
Bad, bad things: Bioweapons. Scientists could potentially piece together nasty bacterial bioweapons that could survive sunlight and even radiation. (Most natural bacteria are relatively fragile and difficult to “disperse” or spread through the air.)
Nature has some controls of her own. Bacteria must contain certain elements to survive and replicate, and sometimes putting foreign DNA into a bacterium will kill it. There are also size limits.
We can only hope that the good that comes from this technological breakthrough outweighs the bad. Later today, I’m planning to pre-order tickets for an amusement park where you’ll be able to see real live dinosaurs in about 20 years.