Why Do Fish Swim in Schools?

Fish swimming together is a great example of "safety in numbers". In a school, the fish in the middle of the group are well protected from predators and the abundance of the fish in one area may confuse actually confuse the predator making them less efficient on hunting.

There is one downside to being in the middle of the pack - lack of oxygen. Scientists have found that fish swimming in the middle of a school have access to 25% less oxygen than the fish swimming on the periphery. This causes the school to change shape frequently as fish move from the inside to the outside of the formation.

Can foods cause ADHD or make it worse?

Most researchers and physicians feel that ADHD is genetically determined. Looking for a link to this disease and food has been going on for over 35 years yet no definitive information has been discovered.

"Scientific evidence is limited to support the association between food additives and ADHD symptoms," says Dr. Maida Galvez, M.D., director of the pediatric environmental health specialty unit at Mount Sinai School of Medicine, in New York City. "Although it is possible that a very small group of children who are allergic to artificial colorings or preservatives may show improvement in symptoms on restriction diets, evidence is insufficient to recommend routine, widespread use of restriction diets to treat a child's ADHD symptoms."

What makes this even more difficult to study is that most foods contain multiple dyes so knowing exactly which one might cause an increase in hyperactivity is tricky.

Can You Make Yourself Have Hiccups?

Hiccups can be caused by laughing, sneezing or coughing so it probably is possible to cause yourself to have hiccups. Hiccups are usually harmless but can cause discomfort in the diaphragm when they go on for a period of time.

What Causes Sleepwalking?

Sleepwalking happens most frequently in children aged 4-8 years and it appears to run in families. Doctors aren't sure exactly what causes someone to sleep walk but it may be related to fatigue or anxiety.

The episode of sleepwalking can last from less than a minute to 30 minutes. Usually the sleep walker goes back to sleep but may not return to their bed meaning that they wake up in a different place.

Sleepwalking usually decreases as a child gets older.

Source: National Institute of Health

Do Triplets Have the Same DNA?

Multiple births are very interesting. Triplets, if they come from the same egg that divides after fertilization, all have identical DNA. Identical triplets are very rare.

There are two other ways that triplets can occur. Non-identical triplets occur when three eggs are produced and each is fertilized separately, these triplets do not have the same DNA. The second way is for one egg to be fertilized and then divides creating two identical twins with the same DNA and then a second egg is fertilized. In this last example, two babies have the same DNA and third one is close but not identical.

Thank You Students for All of Your Questions

What is it in food that makes me like some things and hate others?

Lots of things can cause someone to love one food and hate another. It could be the texture of the food, the smell or look of the food, or a cultural preference for a food because it reminds you of family traditions.
Scientists have found that people have a preference for creamy sensations as well as for foods that start off solid and melt in the mouth such as ice cream and chocolate.

Another factor in food preferences: People vary—probably based on genetics—in their ability to detect other textures, such as fat, and bitter and sweet tastes. Valerie Duffy, a registered dietitian and professor in the department of allied health science at the University of Connecticut, Storrs, Conn., has shown in her research that adults with a gene that makes bitter tastes more intense consume fewer vegetables containing bitter compounds, such as kale or spinach.

So you can see that taste preferences are really a very complex topic and you would be hard pressed to find a friend who had exactly the same favorite food as you do.

Source: Wall Street Journal 11/8/10

Do Genes Even Control Sleep?

It appears that genes do play a role in how long you sleep.

Geneticists studying sleep duration in people scanned the DNA of more than 4,200 Europeans, looking for genes associated with a person’s average nightly sleep time. The team found that people who have one version of a gene called SUR2 sleep about 28 minutes longer than people who have another version of the gene, said Karla Allebrandt of the University of Munich, who presented the research November 5 at the annual meeting of the American Society of Human Genetics.

Last year researchers from the University of California, San Francisco reported that a rare variation in DEC2, a gene involved in regulating the body’s daily rhythms, is associated with sleeping almost two hours a night less than average.

Source: Science News 9/12/10, p. 11.

Is BPA Found in More Than Water Bottles?

I know you about BPA before in water bottles but I just heard that it is in foods too - is that right?

Great and very current question! The newest research on BPA* in foods was done close to home by the University of Texas School of Public Health. They shopped grocery stores in Dallas and then went back to the lab to analyze the foods. Here is what they found: "the Texas contingent locally purchased three samples of each of 31 types of canned or plastic-packaged foods. Another four examples of fresh meat and eight different types of pet food were also collected. All were analyzed for BPA — and 60 percent of the different food products hosted measurable quantities. Ironically, pet food contained less of the pollutant than did most of the items destined for human consumption."

The tested foods weren't just generic, cheap brands but well known foods like Del Monte Fresh Cut Green Beans sporting 26.6 to 65 nanograms of BPA per gram of product; Progresso Light Homestyle Vegetable and Rice Soup with 15.6 to 22.7 ng/g; Campbell’s Condensed Chicken Noodle Soup with 4.46 to 7.05 ng/g; and Chef Boyardee Spaghetti and Meatballs with 4.31 to 5.04 ng/g.of food.

Should we be concerned about this finding? These levels may not be harmful when looked at individually but over time and with use of multiple products the exposure to this chemical may be much higher.

* BPA or Bisphenol A is a chemical that acts as a hormone in the body.

Source: Science News Novemeber 2, 2010

What Can You Tell Me About The Purple Potato?

The Maine Potato Lady has this to say about the new and very popular purple potato: "Majestic purple flesh inside satiny purple skin beautifully describes this newly-released variety...All Blue crossed with a white fleshed chipping variety has produced a royal potato exceptionally high in anthocyanins, an antioxidant". The web site is selling these potato plants and has them labeled as organic.

This is a great example where plants that are raised organically are still genetically modified. Many time consumers think that "organic" is another word for healthy and pure and don't realize that their food is genetically manipulated by scientists.