The molecular epidemiology of Huntington disease is related to intermediate allele frequency and haplotype in the general population

Huntington disease (HD) is the most common monogenic neurodegenerative disorder in populations of European ancestry, but occurs at lower prevalence in populations of East Asian or black African descent. New mutations for HD result from CAG repeat expansions of intermediate alleles (IAs), usually of paternal origin. The differing prevalence of HD may be related to the rate of new mutations in a population, but no comparative estimates of IA frequency or the HD new mutation rate are available. In this study, we characterize IA frequency and the CAG repeat distribution in fifteen populations of diverse ethnic origin. We estimate the HD new mutation rate in a series of populations using molecular IA expansion rates. The frequency of IAs was highest in Hispanic Americans and Northern Europeans, and lowest in black Africans and East Asians. The prevalence of HD correlated with the frequency of IAs by population and with the proportion of IAs found on the HD-associated A1 haplotype. The HD new mutation rate was estimated to be highest in populations with the highest frequency of IAs. In European ancestry populations, one in 5,372 individuals from the general population and 7.1% of individuals with an expanded CAG repeat in the HD range are estimated to have a molecular new mutation. Our data suggest that the new mutation rate for HD varies substantially between populations, and that IA frequency and haplotype are closely linked to observed epidemiological differences in the prevalence of HD across major ancestry groups in different countries.

Anorexia nervosa and body dysmorphic disorder: A comparison of body image concerns and explicit and implicit attractiveness beliefs

Although body image is central to the etiological models of anorexia nervosa and body dysmorphic disorder, studies comparing body image and beliefs about attractiveness between the disorders are rare. Sixty-nine individuals (anorexia nervosa: n=24, body dysmorphic disorder: n=23, healthy controls: n=22) completed self-report measures (body image and general psychopathology), diagnostic interviews, and Go/No-Go Association tasks measuring implicit associations. Compared to controls, both clinical groups exhibited greater negative body image, a more negative attitude toward their physical selves, and more dysfunctional coping strategies (ps<.001). Also, both clinical groups shared greater explicit beliefs about the importance of attractiveness (ps<.001). In addition to supporting previous research with regard to comparable body image disturbance, this study also showed that beliefs regarding the importance of appearance (e.g., "one must be attractive to be successful") might be a fruitful target for therapy across both disorders.

Overlapping addictions and self-esteem among college men and women

To examine whether there is a tendency for individuals to be multiply addicted, overlapping addictions to common substances (alcohol, caffeine, chocolate, cigarettes) and activities (exercise, gambling, Internet use, television, video games) were studied in 129 college men and women. Contrary to previous research, moderate to large correlations were found, both within and between substances and activities. Self-esteem was positively related to exercise but unrelated to the remaining addictions. Several gender differences in addictive tendencies were also revealed: Men scored higher than women on addiction to alcohol, cigarettes, gambling, television, and Internet use, but women scored higher on caffeine and chocolate. The results have implications for theories of addiction and suggest new directions for the study of addiction among normally functioning young adults.

Theodore von Kármán and Applied Mathematics in America

The emergence of applied mathematics as a discipline in the United States is traditionally associated with World War II. Hungarian-born Theodore von Kármán was among those who had waged a long and vigorous campaign well before the war to make applied mathematics respectable to engineers and mathematicians. While advocating the use of mathematics and physics to solve applied problems, he challenged the prevailing philosophy of engineering programs, locked horns with recalcitrant journal editors, and generally encountered the obstacles to building a discipline that cuts across conventional boundaries.

Effect of Transcendental Meditation versus resting on physiological and subjective arousal

On four successive days, 10 highly trained and experienced meditators were asked to relax for 5 minutes, meditate for 20 minutes, and then relax for 5 minutes. In contrast, 10 other subjects who had no training or experience with meditation were asked to relax for 5 minutes, rest for 20 minutes, and then relax for 5 minutes. Physiological arousal (heart rate, skin resistance, respiration rate, systolic blood pressure, diastolic blood pressure) and subjective arousal (cognitive, somatic, relaxation) were measured throughout the experiment. Results indicated that (a) prior to meditating or resting, meditators tended to have higher heart rates and diastolic blood pressure than did nonmeditators, (b) meditation was associated with generally reduced arousal, but (c) while meditating, meditators did not evidence lower levels of arousal than nonmeditators did while resting. This investigation employed controls, which were not used in previous investigations, and the results place qualifications on previously reported results. The results have implications for the study of personality functioning, stress management, and psychotherapy.

Effect of Transcendental Meditation versus resting on physiological and subjective arousal

On four successive days, 10 highly trained and experienced meditators were asked to relax for 5 minutes, meditate for 20 minutes, and then relax for 5 minutes. In contrast, 10 other subjects who had no training or experience with meditation were asked to relax for 5 minutes, rest for 20 minutes, and then relax for 5 minutes. Physiological arousal (heart rate, skin resistance, respiration rate, systolic blood pressure, diastolic blood pressure) and subjective arousal (cognitive, somatic, relaxation) were measured throughout the experiment. Results indicated that (a) prior to meditating or resting, meditators tended to have higher heart rates and diastolic blood pressure than did nonmeditators, (b) meditation was associated with generally reduced arousal, but (c) while meditating, meditators did not evidence lower levels of arousal than nonmeditators did while resting. This investigation employed controls, which were not used in previous investigations, and the results place qualifications on previously reported results. The results have implications for the study of personality functioning, stress management, and psychotherapy.

Early changes in the forearm circulation following transient increase of local external pressure

1. The pressure at the surface of a segment of forearm enclosed in a plethysmograph was abruptly raised from atmospheric level to +40 mm Hg, held at the new level for 4 sec, and abruptly dropped to atmospheric level.2. Forearm circumference (V(f)) equivalent to the volume of a small segment of forearm, was monitored with a mercury-in-rubber strain gauge. Pressure was measured in the cylinder (P(p)) in veins exposed to external compression (P(v, e)), and in the radial artery exposed to compression (P(ra)).3. Forearm blood flow was measured by venous occlusion plethysmography before, and after, release of external compression. There was, on average, over the 3rd and 4th second after release of pressure, a 2.4-fold increase of inflow, as compared with resting level.4. By the 15th second after release of compression, forearm blood flow had returned to its previous resting level.5. The increase in blood flow after compression appears to be due to active reduction in vascular resistance, for refilling of the arteries and arterioles would be completed before the increased flow was recorded; venous backflow can be excluded, and the pressure difference for flow (arterial minus venous) is virtually unchanged.