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.
Biology. a profound change in form from one stage to the next in the life history of an organism, as from the caterpillar to the pupa and from the pupa to the adult butterfly
There are few things more magical than watching a caterpillar turn into a chrysalis and then a butterfly. It’s the beginning of butterfly season, and soon you’ll be able to find monarch caterpillars on milkweed. Just this morning, I spotted a Tiger Swallowtail butterfly by the lake. Not only is it fascinating to observe metamorphosis, it is a great opportunity to create some fantastic artwork for your science notebook!
When the weeds in your area start to get big, take a trip to a park, or a farm, or even a weedy lot and search for some milkweed. (See photo below.) Look carefully on the plants, and there’s a good chance you’ll find a Monarch caterpillar like the one my daughter is watching at in the photo at the top of this page. If you find another type of caterpillar, take whatever plant you find it on with you as food. Carefully take the caterpillar and plenty of milkweed and place them in a large see-through container. We used an old plastic pretzel container, but a large jar or Tupperware container would work too. Just be sure to punch air holes! I put the milkweed in a little vase with water to keep it alive, but a friend told me you can put the leaves between damp paper towels and keep them in the fridge, getting them out when you need fresh ones.
milkweed
Last year, I planted butterfly weed, a type of milkweed, in our garden in hopes of getting caterpillars right in our own backyard and it worked! Just plant milkweed or other butterfly-friendly plants this spring and summer if you want a butterfly gardenof your own. It’s a great way to help the butterfly population. Swallowtail caterpillars like dill and I’ve seen caterpillars in my parsley too!
Once you have your caterpillar, all you have to do is make sure it has plenty of leaves to eat. Occasionally, you’ll have to dump out the caterpillar poop, of which there is a surprising amount. Get out your science notebook or just some paper and draw the caterpillar and the milkweed. When it is ready to form a chrysalis, the caterpillar will hang upside down and look like the letter J. Draw the chrysalis, and finally, the beautiful butterfly that emerges! Keep track of how the caterpillar is growing and how long it spends as a crysallis before hatching.
A few years ago, my kids and I were lucky enough to see the caterpillar turn into a chrysalis. It only takes a few seconds and is easy to miss, but it is truely amazing. If you’re lucky and patient, you may see it too. Here is a link to a short video showing what happens.
There’s nothing quite like taking the lid off your butterfly house and watching a Monarch soar away into the sky.
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.
This afternoon, I buzzed through Michael Pollan’s “Food Rules”, which are basically his Cliff Notes on a healthy diet. His mantra is “Eat food. Not too much. Mostly Plants,” which is hard to argue with when you look at the superior health of nations who eat according to those rules. Here in America, where we eat mostly highly processed, sweetened and fatty foods, we’re on the verge of a national epidemic. Obesity and diabetes will kill more and more people each year, young and old alike, and further cripple our ailing health care system if we don’t change our eating habits. Americans literally can’t afford to keep eating this way.
Here are some of my favorite food rules from the book:
#13 “Eat only foods that will eventually rot.” It is scary that there are foods that even bacteria and fungi won’t touch.
#19 “If it came from a plant, eat it. If it was made in a plant, don’t.” I can follow this maybe 70% of the time, but I love cold cereal.
#27 “Eat animals that have themselves eaten well.” Costs a little more, but who wants mad cow disease?
#36 “Don’t eat breakfast cereals that change the color of milk.” My kids and husband love Fruity Pebbles, but I ALMOST never buy them.
#37 “The whiter the bread, the sooner you’ll be dead.” Complex carbs rule.
#41 “Eat more like the French. Or the Japanese. Or the Italians. Or the Greeks.” How do you say “yum” in all those languages?
#43″ Have a glass of wine with dinner.” My favorite food rule.
#44 “Pay more, eat less.” Why are people willing to spend money on everything EXCEPT healthy food?
#58 “Do all your eating at a table.” This is harder than it sounds, but a great rule and teaches your kids good eating habits.
#59 “Try not to eat alone.” Eating is most enjoyable when it’s a shared activity.
#63 “Cook.” We only order pizza once a week. That’s not so bad, is it?
#64 “Break the rules once in a while.” My second favorite rule and essential to the sanity of anyone with kids to feed.
So, this weekend, call some friends, cook a good meal (that includes a salad) and open a bottle of wine. You’ll just be following the rules.
When I was mashing up avocados with lime juice and salt the other day to satisfy my craving for guacamole, my kids asked if they could keep the pits. I suggested we sprout them and showed them how to poke toothpicks into the pits and balance them in a glass of water with the pointed end up and the round end sitting in the water. I had no idea that our little experiment would send me on a trip down memory lane.
As a kid, I spent my summers living in California while my dad did research at a physics laboratory in the Bay Area. Around 1976, we spent an entire year there when my dad took a sabbatical. We rode the ferry to Sausalito, feasted on hot fudge sundaes at Ghiradelli square and sat on the Berkeley pier eating clam chowder from Spanger’s. Every summer, we took backpacking trips along the coast of Point Reyes, fished in the Truckee river near Lake Tahoe and explored the High Sierras. I was a lucky kid.
The funny thing is, what I remember as clearly as all those adventures is that we almost always had an avocado seed sitting in our kitchen window and now, every time I look at our science experiment, I think about my mom and the summers of my youth. Maybe I’ll try to keep an avocado pit growing in my kitchen from May to August so that some day, one of my kids will show their own children how to sprout an avocado pit and remember our summers together.
I was never an enthusiastic chemistry student. That being said, I have to admit that chemical reactions can be lots of fun to watch as things turn colors, make bubbles, or smell different. They can change from liquids to solids and they can even explode.
There are many fun, safe chemical reactions you can perform with your kids. I’d recommend having them put on safety goggles or sunglasses, if you have them, for most experiments where you mix things together. As you can see, my children aren’t wearing any eye protection for this project, but I did have them stand back to make sure the balloon wouldn’t explode the first time we did it. Just use common sense.
You will need: a balloon, an empty soda bottle, white vinegar, and baking soda. Put 1/4 to 1/2 cup vinegar into the soda bottle. Then, hold the mouth of the balloon open and have your child pour about a teaspoon of baking soda into the balloon. Shake the soda into the “bulb” or the main part of the balloon. Then, stretch the mouth of the balloon over the mouth of the bottle, trying to keep the main part of the balloon off to the side (so the soda isn’t dumped into the bottle right away.) Ask them what they think will happen when you mix the two things together. Finally, let your child shake the soda into the bottle, all at once.
Stand back and watch what happens!
If the seal is tight, which it should be, the reaction between the soda and the vinegar will form a gas that inflates the balloon. Our balloon was big enough that it didn’t explode, but if your balloon is over-inflating, simply take it off of the bottle. Just pay attention and you’ll be fine.
What happened?
Baking soda is a chemical called sodium bicarbonate. Vinegar is called acetic acid. These two chemicals react to form some different chemicals. One of these is carbon dioxide gas. This is called a chemical reaction. The gas is what inflates the balloon. We know a reaction is happening because we can see bubbles forming.
What else do your kids notice about the reaction? Have them record (or help them to record) what they see in their science notebooks. Older kids can draw what they see and then try to describe it. My kids loved it when I wrote down their descriptions for them before they could write. Have them touch the bottle. Does it feel warmer or cooler than room temperature? A temperature change is also a clue that a chemical reaction is occurring! They could even time how long it takes for the balloon to inflate.
My kids did this experiment three times and would have kept doing it all day. They thought it was pretty great. Give it a try! Put those budding brains to work!
Move over, red meat. High Fructose Corn Syrup (HFCS) is the new bad boy of the food industry. Although companies like Hunt’s, Gatorade and Pepsi are rushing to replace HFCS with sugar, it’s ubiquitous in our nation’s food supply. Not only was there a recent report of mercury contamination in HFCS, but in February, a study came out of Princeton University suggesting that rats fed HFCS for 6 months gained more weight, had more body fat and showed higher triglycerides than rats fed the same amount of table sugar (sucrose.) A flurry of debate, fueled in part by the corn syrup industry, followed, calling into question the significance and accuracy of the study. In the meantime, Michael Pollan’s book “The Omnivore’s Dilemma,” and films like “Food Inc.” and “King Corn” accuse the corn industry of practically force-feeding Americans corn products.
I’ve been skeptical about all the negative press that High Fructose Corn Syrup is getting. As I recall from my biochemistry class, all sugars are broken down into their simplest forms so the body can use them for energy. They can be used immediately, or stored for later use either as fat, or as a carbohydrate called glycogen.
Reading more, I learned that sucrose, and HFCS are both composed of two simple sugars: glucose and fructose. Both contain about 50% glucose and 50% fructose. The big difference is that the fructose molecules in HFCS float free, while each fructose molecule in sucrose is stuck tightly to a glucose molecule.
The Princeton researchers think the unbound fructose in HFCS is more likely to be stored as fat than the bound fructose molecules in sucrose. They may be on to something.
It makes sense that sucrose and HFCS would be processed, or metabolized, differently. Our body has to do some work to break apart the glucose and fructose in sugar, while the fructose in HFCS is instantly available to our metabolic machinery. For thousands of years, our bodies have evolved to break down plants, whole grains and meat to power our cells. Now, we’re essentially shoveling pure energy down our throats in the form of HFCS, white flour and other processed foods. I don’t think it will be long before researchers have more concrete evidence that corn syrup is not equivalent to sugar in the human diet.
I’m not going to knock myself out avoiding foods containing HFCS, but as a mom and a label reader, I will definately choose products sweetened with sugar. Call it a gut feeling.
The oil spill in the Gulf of Mexico is devastating news to the already fragile and damaged ecosystems in the area. To demonstrate how hard it is to remove oil from water, and what materials work best, I found this experiment online at tryscience.org and decided to have my kids try it. It was messy and disgusting and oil got all over everything. In other words, it was a great demonstration of how hard it will be to clean up the mess made by BP’s Deepwater Horizen oil rig, which exploded on April 20th.
Polyester scraps soak up oil.
You’ll need a clear bowl, water, yellow oil (vegetable, corn or canola will work,) cotton balls, cheese cloth, polyester cloth (the website said polypropylene, but I couldn’t find any,) feathers, and a spoon.
Put some water in the bowl and pour in some oil. I probably added a cup so it would cover the water. Then, using spoons and the other materials, try to remove the oil from the water. What works best?
Oil is hard to clean off feathers.
We put our feathers in oil and then tried to clean them off using dish soap and water, which is how they clean off marine birds covered with oil following oil spills.
Polypropylene is a synthetic material made from Carbon and Hydrogen, the same elements in oil. Oil is attracted to polypropylene, and both float on water, so polypropylene is often used in cleaning up oil spills. You can also find it in gloves and sock liners.
If one cup of oil is this hard to clean up, can you imagine the mess pouring into the Gulf of Mexico right now, at the rate of about 210,000 gallons a day (according to the New York Times?) I’m attempting to find out if there’s any way to help, aside from travelling to the area to help clean off wildlife by hand. As soon as I learn anything, I’ll post it here! Here is a link to a map that is tracking the spill.
Sandwiched between oil spills and militant lairs in the paper this morning, I found hope for millions of people.
The New York Times reported that a new drug therapy offers hope to children and adults suffering from a relatively common genetic flaw that causes autism and mild to severe retardation. According to the article, one child in five thousand is born with Fragile X Syndrome, which is the most common inherited cause of mental retardation. (Down Syndrome is not inherited.) Fragile X patients appear to experience an overload of brain signalling and the drug, manufactured by Novartis, appears to help by slowing down this excessive talk between brain cells. Researcher hope this will allow patients to form memories, learn and develop more normally. If further studies bolster these initial trials, performed in adults, the drug may also hope for patients with autism not caused by Fragile X. “This is perhaps the most promising therapeutic discovery ever for a gene-based behavioral disease,” said Dr. Edward M. Scolnick.
For centuries, people have harvested corn by hacking it off, six to fifteen inches above the ground. A caterpillar called the corn borer appears to have adapted its behavior to the corn harvest by travelling back down the stalk to a safe height, before spinning its cocoon. This week, the Science Times reported on a study that suggests that, by descending to the bottom of the stalks, the bugs avoid being chopped off when the corn is harvested. Researchers at McGill University think that “over generations, those caterpillars that did not descend, or did not go down far enough, did not survive.” In the article, Dr. Calcagno suggests that the likeliest explanation for this behavior is the selection pressure of harvesting over generations. In other words, only the caterpillars that crawled down survived to reproduce and make baby bugs, until only caterpillars with the family trait of crawling down remained in the population.
Our family farm in Iowa was once a dairy farm.
Similar forces are at work on bacteria that live in animals and humans, only instead adapting to harvest, they’re adapting to constant exposure to antibiotics. As a result, many harmful bacteria are finding ways to “outsmart” antibiotics. This is, in part, due to the mind-boggling volume of these drugs fed to animals produced for food. I can’t give you a number, because according to the Center for Disease Control’s website, the amount of antibiotics fed to farm animals is not available to the public or to government agencies.
Feeding animals antibiotics helps them grow. No one knows exactly why. Unfortunately, using these drugs as growth enhancers, or even to protect them from disease, often creates antibiotic-resistant strains of bacteria that have the potential to end up in our food supply. These drug-resistant pathogens are especially dangerous to people who live and work on farms ( just ask Russ Kremer, who was gored by one of his hogs and nearly died from an antibiotic-resistant infection.) In reponse to the global threat presented by antibiotic resistance, the World Health Organization recommended that antibiotics used in humans should not be used to promote growth in food animals.
Healthy animals occasionally need to be treated for infections, but feeding animals antibiotics for growth benefits is a risk no one should be taking. A huge amount of money is spent each year on these drugs so producers can get top dollar for their animals. My worry is that the additional costs to public health are not being considered, especially if our pharmaceutical arsenal is rendered useless by this practice.
Want to learn more? You can check out the CDC’s website for a wealth of information on antibiotic resistance. Their program “Get Smart on the Farm” promotes appropriate antibiotic use in animals.
