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Update (Jan. 20, 2007):Q: Why is the most recent data on the average weights of Americans so outdated, when Canada's information is current to 2005? Is the data available via a different location or is just not available to the public? Ezell, San Antonio, TexasA: The USA government schedules its comprehensive tests (HANES studies) about five years apart. I asked USA Public Affairs Specialist Mary Jones of the National Center for Disease Control when data from the next study will be available. "It is in the collection stage; we don't have a release date as yet, maybe some time next year," she said. The Canadians collect their data "every two years," says statistician Heather Orpana of Statistics Canada in Ottawa. "We will have another survey in the field in 2007/2008, which will also be collecting measured height and weight data." Further Reading:Body measurements, National Center for Health Statistics Average American female size, WonderQuest An anthropometric approach to the measurement of living standards (Mexico) by Moramay López-Alonsa, Stanford University
Do you want to learn about Nutrition?
If you are concerned with the
size of your
body, find out where you can find information on
loosing weight. No matter if
you are big or small, eating healthy and exercising are important for a life if
you want to live longer. The Question of the Month: readers contribute answers Follow up: Before getting to this month's question, first a
follow up to last month's question on twitching lizards' tails: "With
reference to the shedding of a tail that continues to twitch, there is a
luminous marine annelid [a worm] that sheds luminous scales and swims away,
presumably a way to cause a predator to eat scales instead of the animal
itself," emails
biologist
J.
Woodland Hastings, of Harvard University This month's question:
Photo courtesy of Akkia and Wikipedia. A: The basic answer is middle age. But, different kinds of memory abound — from remembering when Kennedy was shot to remembering to remember your next dental appointment. Perhaps the most useful memory is the one closely tied to thinking abilities. It's called working memory, and allows us to focus on a task (like, paying attention to traffic) when distracted by irrelevant information coming in (a friend's conversation). Having a good working memory is strongly related to complex thinking tasks, such as, comprehending what we read, solving problems or learning a new language. The age at which our working memory peaks is 45, according to psychologist H. Lee Swanson of University of California, Riverside. After examining 778 people, ranging in age from six to 76, he found working memory got better as children got older, reaching peak level at age 45, then steadily declining. Moreover, the reason working memory declined is, "as we get older, we run out of places to put new information." It's a storage problem, "not related to our reading or math abilities," Swanson says. Moving on to another type of memory (semantic): the ability to remember words, their meaning and general facts, such as, 'Paris is the capitol of France.' Over a ten-year period, the Swedish based Betula Project looked at folks in ten age groups from 35 to 80 years old. "The middle-aged adults [35 to 50] performed at the highest level," reported the project. Even better, "no age-related deficits were observed before 75 years of age." Indeed, how well we're educated appears to be a more important factor than our age in how well we can remember words and facts. How about remembering to remember? We retain the ability to remember such things as an upcoming appointment as age advances. People from 61 to 70 years remembered such things as well as those from 18 to 30 years. Such memory "started to decline only in those participants who were in their 70s," wrote psycholgist L. Kvavilashvili of the University of Herfordshire in England. "It's a poor sort of memory that only works backwards," Through the Looking Glass by Lewis Carroll. Further Reading: What develops in working memory? A life Span Perspective by H. Lee Swanson, University of California, Riverside Semantic memory functioning across the adult life span, Betula Project Mechanisms of Prospective Memory and Aging by Lia Kvavilashvili, University of Hertfordshire, England Memory, Wikipedia Readers' Answers (a monthly contribution by readers,
published on the first Tuesday of the month):
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