Web edition: January 24, 2005
Print edition: January 29, 2005; Vol.167 #5 (p. 79)
In "Profiles in Melancholy, Resilience: Abused kids react to genetics, adult support" (SN: 11/20/04, p. 323), you report on a study in which it was found that female monkeys raised in a stressful situation drink alcohol to excess only if they possess just the short serotonin-transporter gene. If a positive correlation were to be found in abusers of drugs and alcohol and the presence of two copies of this gene, this could lead to a method for identifying persons at risk for substance abuse.
Victoria, British Columbia
The study in "Asthma Counterattack: Symptoms decline when families fight allergens at home" (SN: 11/27/04, p. 344) is missing the boat. They should use families that have eliminated asthma triggers without medications. In our safe, chemical-free home, we have been able to protect our health. Avoiding asthma triggers has resulted in one son being cured of asthma and my other son and I being under control with no medications.
Linda J. McElver
San Luis Obispo, Calif.
The resonance discovered in the star HD 202206 system is not unique, and it isn't true that "[t]his particular synchrony has never been seen before in a planetary system" ("Extrasolar Planet News: Superplanet or brown dwarf?" SN: 11/27/04, p. 341). Resonances abound in the solar system. The orbital periods of the Galilean satellites of Jupiter, many asteroids' orbits, Jupiter's orbit, and Pluto's orbit with Neptune are some examples. Resonances also exist in numerous extrasolar systems discovered over the past 10 years. Also, the extrasolar system around HD 37124 that consists of two planets with periods of 155 and 31 days shows a 5:1 mean motion resonance, so even the particular commensurability seen for HD 202206 is not new.
San Pedro, Calif.
There are clearly other synchronies in our solar system. However, researchers say that the 5:1 synchrony is new and doesn't describe the planets of HD 37124, which have approximate periods of 150 days and 1,500 days. The word particular was intended to describe only the 5:1 synchrony, which has also been suggested as one of several ratios for two planets in another system, HD 160691.R. Cowen