Frozen Grand Central
An amazing video on Frozen Grand Central Station: what happens when over 200 people freeze in place simultaneously.
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February 15, 2008
February 11, 2008
Dave Gray's Clever Sticky-Note Trick
This is a simple but clever trick to using sticky-notes (aka Post-It Notes) from Dave Gray, founder of Communication Nation:
February 10, 2008
Does flouride work?
Just how important is flouride for protecting teeth?
All over the world tooth decay is decreasing, even though most of the world doesn't have flouride in the water When the Centers for Disease Control (CDC) nominated water fluoridation as one of the top 10 public health achievements of the 20th century, it published a graph (see Figure 1), which showed the reduction of cavities in US children coupled with the increase in water systems that have been fluoridated since the 1960's. The CDC referred to the graph with the statement:But is flouride dangerous?
"as a result [of water fluoridation], dental caries declined precipitously during the second half of the 20th century."
However, what the CDC failed to mention is that similar declines in tooth decay have occurred in virtually every western country, most of which do not fluoridate water (see Figure 2).
If you ingest enough, you can get dental fluorosis. Some alarmists say it is dangerous. The more serious health concern is that dental fluorosis is not the only harmful health effect that results from overexposure to fluoride. Fluoride has been linked in government and scientific reports to a wide range of harmful health effects, including: bone and tooth decay (including dental and skeletal fluorosis, bone pathology, arthritis, and osteoporosis) Alzheimer's, memory loss and other neurological impairment, kidney damage, cancer, genetic damage, and gastrointestinal problems. In addition, fluoride has been found to leach lead from old water pipes and soldering material, which has resulted in increased lead levels in people.Other flouride concerns:
- Since mid-1997, the F.D.A. has mandated all toothpastes containing fluoride to carry this warning: "If you accidentally swallow more than used for brushing, seek professional help, or contact a poison control center immediately.". Even on many fluoridated children's toothpastes, there is a warning to keep out of the reach of children under 6years of age!
- That according to the Physicians' Desk Reference: " In hypersensitive individuals, fluoride occasionally cause skin eruptions such as atopic dermatitis, eczema, or urticaria. Gastric distress, headache, and weakness have also been reported. These hypersensitive reactions usually disappear promptly after discontinuation of the fluoride."
- That the Canadian Dental Association recommends: "Fluoride supplements should not be recommended for children less than three years old."
- That from 1990 to 1992, the Journal of the American Medical Association published three separate articles linking increased hip fracture rates to fluoride in the water. (Click here for copy of article) That in the March 22, 1990 issue of the New England Journal of Medicine, Mayo Clinic researchers reported that fluoride treatment of osteoporosis increased hip fracture rate and bone fragility.
Why Doesn't Silk Decompose?
I was wondering why silk, which is not so dissimilar to any kind of cocoon material, doesn't just decompose. After all, the streets aren't exactly littered with cocoons. Here's what I found:
Why does the silk made of protein not decompose by fungi and bacteria like all other proteins? We conserve protein by cooking, salting, drying or adding acid. In spider silk there are three substances that are important for its durability: pyrolidin, potassium hydrogen phosphate and potassium nitrate. Pyrolidins can be found in dyes and plant poisons and are very hygroscopic (binds water). This substance prevents the thread from drying out. Pyrolidin is also found in high concentration in the glue of catching threads. Potassium hydrogen phosphate makes the thread acidic and prevents fungal and bacterial growth. A low pH causes denaturation (become insoluble) of proteins. A phenomenon we can observe in sour milk. Potassium nitrate prevents this and the proteins are salted which prevents bacterial and fungal growth.
Tipping for Takeout?
From Ask Yahoo:
Tipthepizzaguy.com, an invaluable source we've deferred to in the past, lays it out -- if you pick up a pizza, no tip is required, but, "The tip is still expected at other restaurants when you order pick-up." In these cases, your tip is for the waiter or waitress who has to prepare and package your order.
So a tip is in order, but how much is appropriate? Well, according to one source, it depends on the establishment. If it's a restaurant that features take-out meals, 10% is appropriate. If it's a restaurant that is really more of a dine-in place, the typical 15% is in order.
Phyllis Richman, a restaurant critic for the Washington Post, says that she doesn't usually tip at a carryout establishment, although she may add something to the jar on the counter. But if she is getting a meal to go from a sit-down restaurant, she will tip up to 10%.
Waiters and waitresses are required to report 8% of their total sales to the IRS as tips. At some dine-in restaurants, takeout orders are added to a waitperson's total sales and fall under the 8% rule. And even though you may be eating at home, the waitperson is still providing you a service by preparing and packing your food.
As one source succinctly states, "When in doubt, leaving a couple of bucks is always appreciated."
Lead in Household and Car Keys Makes Them Unsafe for Kids
From California Childcare Health Program (pdf):
A new study has found that there is also lead in some house and car keysFrom Gordon Research:
Many parents give keys to their children to occupy them while the parents are busy shopping or doing chores. Children then put the keys, or their hands, in their mouths, and the lead can get in their bodies. Because children often put their hands in their mouths, they can be exposed to lead many times.
After learning about the lawsuit, Bollinger, 35, grew more worried when her keys registered in the dangerous level on her home lead tester.
Lockyer said some keys leave lead on hands at a level that is up to 80 times above the 0.5 microgram per-day limit, while the average level detected on hands was about 19 times above the "no significant risk level."
"My house keys and my car keys that I use every day tested positive," Bollinger said. "I'd like to figure out how to get nonleaded keys."
The Most Unusual Eye Colors
From Wikipedia:
Green
Green eyes are the product of moderate amounts of melanin. They are most often found among people of North and Eastern European descent, and to a lesser extent, in Southern Europe, parts of Central and South Asia.. Green eyes are an uncommon eye color. In Iceland 88% of the population have green or blue eyes. Other ethnically Nordic countries like Sweden, Denmark, Germany, Norway, and (less) the Netherlands have a high percentage of green eyes. The Pashtuns are often called "Hurry Ankehian Wallay": the green-eyed people. Of all the normal colours of human eyes, it would appear that green eyes are the rarest. Studies have also concluded males perceive females with green eyes as appearing "intellectual".
Violet
The appearance of violet eyes is thought to occur from the mixing of red and blue reflections. Some albinos have eyes that appear violet.
A famous celebrity who is well known for having "violet" eyes is actress Elizabeth Taylor.
Red
'Red' eyes are also found in an extremely small (<0.001%) percentage of the world's population. This is believed to be a result of either large quantities of the normally scarce red areas in the eye, or a small leakage of blood into the iris; however the number of people on record as having red eyes apart from albinos, is believed not to exceed 20 (Recording of this condition started in 1964).
Why Are Allergies on the Rise?
From MSN Health:
Identifying what's responsible for the increased prevalence of allergies is difficult--but several theories abound. One is the so-called "hygiene hypothesis," which posits that we've done such a good job eradicating diseases and sanitizing our environment that our immune systems are looking for something to do. Another theory is that we're introducing potentially allergenic foods too early, or too late, into young children's diets.
Could it be that we're all exposed to more and more of the "Big Eight" allergens through processed foods and this might be contributing to the rising rates? "Possibly," says Annie Khuntia, M.D., clinical associate of allergy and immunology at the University of Chicago. "But it's really difficult to come to this conclusion because there isn't any evidence to support it. This issue hasn't been studied." At this point, say experts, most hypotheses tend to be, well, educated guesses. "Even the big players tend to disagree," says Khuntia. "It's an evolving science."
From UK Independent:
One of the most extraordinary increases has been in peanut allergy, up 117 per cent between 2001 and 2005. An estimated 25,000 people in England are affected, and many are at risk of a severe reaction if they are exposed to the nuts. The report says up to 7 per cent of infants have a food allergy - many are sensitive to egg, but this tends to improve with age. Among adults, the Institute for Food Research estimates that up to 2 per cent are affected. This is often distinguished from food intolerance which is less specific and thought to be more widespread.
The report says that guidance to pregnant women and children not to eat peanuts should be withdrawn because it may actually be exacerbating the problem of peanut allergy. In parts of Africa, where peanuts are made into a soup used for weaning and in Israel where they are incorporated into a rusk for babies, the problem of peanut allergy does not exist. Depriving children of exposure to peanuts early in life might increase the risk of an allergic reac tion later.
No one really knows [why allergies are on the increase]. Allergy is an area of medicine more full of puzzles than most. Take hay fever. In 1955, just over five GP consultations in 1,000 were for hay fever. By 1971, the number had doubled and a decade later it had doubled again. Yet this increase was occurring as pollen counts were falling owing to the cut back in agricultural land.[The hygiene hypothesis] is the leading theory to explain the rise, devised by David Strachan in the 1980s. It can be summed up in a sentence: as we lead cleaner, germ-free lives, and are exposed to fewer illnesses in childhood because of smaller families, our immune systems are under-developed and over-react when exposed to allergens such as grass pollen, house dust mites and cat hairs. The theory has been confirmed by many studies since. Children raised on farms with livestock have a third fewer allergies than those who are not.
However, the theory does not account for the extraordinary increases in allergies such as asthma seen in townships in Tanzania, on Tristan Da Cunha (the tiny island in the south Atlantic) and other parts of the world remote from the infrastructure of developed nations.