Lots of people go to bed with a good book (or even a bad one), knowing that within a few pages, the words will start to blur and the head will begin to nod, with sleep soon to follow. At least that's the idea.

Bedtime reading with an electronic device — such as an iPad, Nook or Kindle Fire — is a different story, say researchers at Penn State University. These "electronic devices emit short-wavelength-enriched light, which has a higher concentration of blue light — with a peak around 450 nanometers," said Anne-Marie Chang, assistant professor of biobehavioral health.

In other words, this is light different from natural light, and according to Chang, it may disrupt a reader's sleep cycle by suppressing the release of the slumber-inducing hormone melatonin.

Chang and colleagues observed 12 study participants for two weeks, comparing when they read from an e-reader before bedtime with when they read from a printed book. E-reader readers took nearly 10 minutes longer to fall asleep and recorded significantly lower rapid-eye-movement sleep — the most restful kind.

"Our most surprising finding was that individuals using the e-reader would be more tired and take longer to become alert the next morning," said Chang. "This has real consequences for daytime functioning, and these effects might be worse in the real world as opposed to the controlled environment we used."

Body of Knowledge

An adult human spine compresses roughly 0.59 inch from morning to night.

Get Me That, Stat!

The country with the longest life expectancy at birth is Hong Kong (OK, technically it's a special administrative region of the People's Republic of China), at 83.42 years, followed by San Marino (83.32), Switzerland (82.7), Japan (82.59) and Iceland (82.36), according to a 2011 United Nations survey of 204 countries. The United States comes in 40th, at 78.64.

Number Cruncher

A Dunkin' Donuts bacon, egg and cheese English muffin breakfast sandwich (100 grams) contains 290 calories, 90 from fat. It has 10 grams of total fat, or 15 percent of the recommended total fat intake for a 2,000-calorie daily diet, according to the Calorie Count database.

It also contains 70 milligrams of cholesterol (23 percent), 700 milligrams of sodium (29 percent), 32 grams of total carbohydrates (11 percent), 7 grams of dietary fiber (28 percent), 2 grams of sugar and 16 grams of protein.

Doc Talk

Bolus: a large dose of a drug given (usually intravenously) at the beginning of treatment to raise blood-level concentrations to a therapeutic level. It can also refer to a concentrated mass of a substance, such as chewed food.

Phobia of the Week

Aichmophobia: fear of needles and other pointed objects.

Never Say Diet

The speed-eating record for kielbasa is 21 6.5-ounce links, or 8.5 pounds, in 10 minutes, held by Molly Schuyler. Despite what you might expect, Molly achieved the feat without, uh, kieling over.

Medical History

This week in 1954, The New York Times reported on a new culinary invention: a frozen turkey dinner from C.A. Swanson & Sons, featuring an aluminum foil tray filled with 12 ounces of sliced turkey, cornbread, green peas and mashed sweet potatoes with butter. It sold for $1 and became known as the TV dinner. Other entrees would soon follow — to the chagrin of fitness experts and gastronomes everywhere.

Last Words

"Waiting are they? Waiting are they? Well, let 'em wait." — American Revolutionary War general Ethan Allen (1737-89), in response to an attending doctor who attempted to comfort him by saying, "General, I fear the angels are waiting for you."

To find out more about Scott LaFee and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.