Chance News 34

From ChanceWiki
Revision as of 20:13, 11 February 2008 by Jls (talk | contribs)
Jump to navigation Jump to search

Quotation

One more fagot of these adamantine bandages is the new science of Statistics.


Ralph Waldo Emerson
Fate from The Conduct of Life (1860, rev.1876)

Forsooth

The following Forsooths are from the February 2008 issue of RSS NEWS.

Twenty-six new cases of the inflammatory lung disease sarcoidosis [were seen amongst rescuers] in the first five years after 9/11. Five or fewer rescuers got sarcoidosis anually before 9/11.

New York Daily News
21 September 2007.

Actually, I like the Poles' second idea even better. Instead of re-enacting a battle, they suggested, the summiteers should re-sit advanced level mathematics. Voting weights should be based on the square roots of the member states' populations. (Pocket caclulators allowed.)


Telomeres Tell A Lot

Conventional wisdom, indeed wisdom of any form, indicates that physical activity, a.k.a. regular exercise, is good for you. In particular, intuition would imply that the risk factors for age-related diseases such as diabetes, cancer, hypertension, obesity and osteoporosis would be reduced if people were engaged in physical activity. To make a direct connection between ageing and physical activity, consider a paper in the Archives of Internal Medicine (Vol.168, No. 2, January 28, 2008), “The Association Between Physical Activity in Leisure Time and Leukocyte Telomere Length” by Cherkas, et al.

“Telomeres consist of tandemly repeated DNA sequences that play an important role in the structure and function of chromosomes.” Leukocyte telomere length (LTL) is a proxy variable for one’s biological age as opposed to one’s chronological age. That is, the longer one’s telomeres, the younger one actually is. Conversely, the shorter the telomeres, the more aged.

This study measured the telomeres of 2401 twins who were put into four mutually exclusive categories of physical activity: “Inactive,” “Light,” “Moderate,” and “Heavy” corresponding to “16 minutes, 36 minutes, 102 minutes and 199 minutes” physical activity per week, respectively. The result after adjusting for “Age, sex, and extraction year” was that the “LTL of the most active subjects (group 4) was an average 200 (SE, 79) nt [nucleotides] longer than that of the inactive subjects (group 1)” producing a p-value of .006. “This difference suggests that inactive subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average.” When more complete information was available concerning BMI (biomass index), smoking and SES (socioeconomic status) this reduced the number of subjects to 1531 from the 2401; the LTL difference increased to 213 nt and the p-value increased to .02. Below are a summary table and

http://www.dartmouth.edu/~chance/forwiki/alber1

Figure 1.

item2