Day: May 15, 2007

Science

Percentage confusion redux

by  • 

One day you’re blogging about it, the next day, someone publishes a journal article about percentages and the confusion people have about them.

ScienceDaily: Two Plus Two May Not Always Equal Four: Consumer Study

In the paper “When Two and Two is Not Equal to Four: Errors in Processing Multiple Percentage Changes,” Rao and Haipeng Chen, a Carlson School doctoral alum and assistant professor at the University of Miami, show that consumers treat percentages like whole numbers, and this results in systematic errors in calculation. People simply aren’t coming up with four when they add two plus two. The paper will appear in a forthcoming issue of the Journal of Consumer Research.

Well, what do you expect? It’s not easy to take 35% off 25% in your head, unless your parents and teachers made you do mental math till your head hurt (who am I kidding, I still enjoy doing math in my head and beating people with calculators, though I get worse with every passing year). Companies that sell products based on discounting of already discounted merchandise know that people will add them up in their head and overestimate the discount. It is dishonest marketing at best, and downright deceptive if you’re extremely cynical (I believe the worst of advertisers and PR).

Wow, two posts about percentages in two days, I must have nothing better to do…

sea turtles

Tuesdays with Turtles – Lighsticks Kill

by  • 

Following up on the fishing issues from last week, here’s word that lights used to lure tuna towards longline fisheries attract juvenile sea turtles as well.

Article – Science & Technology – Lightsticks may hold deadly attraction for sea turtles

RALEIGH, N.C. Longline fishermen use lightsticks similar to the glowing tubes that delight trick-or-treaters to lure tuna and swordfish to baited hooks. New research by University of North Carolina-Chapel Hill scientists suggests that for endangered sea turtles the lights may hold a fatal attraction.

Lab experiments by Ken Lohmann, a University of North Carolina biology professor and John Wang, a graduate who is now a research associate at the University of Hawaii and National Marine Fisheries, found that young loggerhead turtles in a tank tended to swim toward lights.

It’s well known that hatchling turtles on a beach will crawl toward lights as they try to find the surf. But researchers did not know whether juvenile loggerheads in the water shared that attraction. Young loggerhead and leatherback sea turtles, which are protected because of declining numbers, are inadvertently hooked during longline fishing.

Well, not so surprising, is it? Bioluminescence is a common enough phenomenon that especially at night, animals will be attracted to light as it can signal food. It’s tricky, but when you try to catch fish, tyou will catch other animals as well. So, when you change something about the way you catch fish, you need to study how it affects other endangered species…

Off topic, but it is ironic that I read this in the ocregister, which is a newspaper from Orange County, California. It reported on work done by UNC Chapel Hill, which is in Orange County, North Carolina.

Health

How Safe Is The US Food Supply?

by  • 

A good summary of the state of food safety regulation in the United States.

How Safe Is The Food Supply?

These known cases make up a tiny fraction of the overall problem–an estimated 76 million illnesses and 5,000 deaths in the U.S. from food poisoning each year. Meanwhile, imports of food, some from countries without strict controls, soared to more than 9 million shipments last year doubling since 2002. The cash-strapped FDA is able to inspect less than 1% of imports. It’s a recipe for disaster. “Our food-safety system in this country is broken,” warned former FDA Commissioner Dr. David A. Kessler at a recent congressional hearing.

Few incidents ever have a body count high enough to shock the country into making fundamental changes. Overall, “we do have a very safe food supply,” says Sanford A. Miller, former director of the FDA’s Center for Food Safety & Applied Nutrition. But the alarms over pet food and vitamin A have lit a fire under lawmakers and executives. On May 2 the Senate rushed to pass a bill by a vote of 94-0 giving the FDA more responsibilities, such as creating databases of adulterated food. Meanwhile, food producers have been holding emergency meetings with suppliers, looking for problems in their factories or supply chains. Companies are “feverishly examining their own purchasing policies and trying to ensure they are followed,” says Kovacs.

Note that it is always tempting to blame the bureaucrats here. Bureaucracy is a dirty word in this country, associated with “red tape”, “corruption”, “standing in the way of business”, “pencil pushers”, “big government”, you name it, they get called it. But, agencies like the EPA and the FDA have competent scientists who know what they are doing. But, without the money and the authority, which is given to them by the political arm of the government, they cannot do much. They have also, in recent years, been headed by political appointees who come from the industry they are supposed to regulate and show a distaste for regulation which is in complete opposition of the mandate they are supposed to fulfill as the head of a regulatory agency.

It’s easy to take potshots at the FDA, but remember who gives them the money, makes the rules and tells them what not to oversee.