Alison Pearce Stevens' Articles
- Population density can determine how much of an impact modern communities have on the climate.
- The American Academy of Pediatrics suggests taking steps to limit children’s exposure to pesticides.
- Scientists find evidence that pesticides, disease and other threats are devastating bees. And that could hurt farmers big time.
- Scientists observe some evolutionary speed demons as they adapt over the course of just a few years to new environmental conditions.
Wash your hands!
That familiar piece of advice helps prevent the spread of disease. Good old soap and water remove the bacteria, viruses and other germs that can make you sick. But is there any big advantage to soap laced with bacteria-killing chemicals? Should people sanitize computer keyboards, shopping cart handles and anything else that others have touched?
Indeed, is it possible to be too clean?
Actually, data show, it is. A growing number of studies suggest that routing too many germs might actually foster life-threatening allergies. If you find that hard to believe, it’s probably because you’ve been taught that germs are bad.
Stem cells are cells that can specialize into many different types. They fall into two main categories: adult stem cells and pluripotent (PLU ree PO tint) stem cells. (Pluripotent means the ability to become many different things.)
Inside your body, red blood cells are constantly on the move. They deliver oxygen to every tissue in every part of your body. These blood cells also cart away waste. So their work is crucial to your survival. But all that squeezing through tiny vessels is tough on red blood cells. That’s why they last only about four months.
Where do their replacements come from? Stem cells.
These are a very special family of cells. When most other cells divide, the daughter cells look and act exactly like their parents. For example, a skin cell can’t make anything but another skin cell. The same is true for cells in the intestine or liver.
While hanging out with friends, Michelle Hackman noticed that many of them texted each other instead of just chatting amongst themselves. That made her curious: Might cell phones be affecting our social interactions — and maybe even our brains?
When Nilesh Tripuraneni set out to make pancakes one morning, he had no idea he’d also wind up with the makings of a first-rate science fair project. But as the high school student sprinkled water on a hot griddle to test its temperature, the dancing droplets got him thinking: What, exactly, was going on beneath them?