Lightning

This Why Files article examines lightning. Lightning is the second deadliest storm-related hazard in the United States. Topics covered include: what lightning is, how it injures and kills, and what has been learned in the past few years from research on nature's electricity. Two experts were interviewed for this article. Educational levels: General public, High school, Intermediate elementary, Middle school

A Fellow\u27s Perspective on Technology in Healthcare

No abstract available

Action, Deontology, and Risk: Against the Multiplicative Model

Deontological theories face difficulties in accounting for situations involving risk; the most natural ways of extending deontological principles to such situations have unpalatable consequences. In extending ethical principles to decision under risk, theorists often assume the risk must be incorporated into the theory by means of a function from the product of probability assignments to certain values. Deontologists should reject this assumption; essentially different actions are available to the agent when she cannot know that a certain act is in her power, so we cannot simply understand her choice situation as a “risk-weighted” version of choice under certainty

Spatial and time domain spectral energetics in the GLAS circulation model

Zonally averaged eddy kinetic energies and time domain energetics spectra were calculated for the GLAS general circulation model. The spatial results show significant improvements in the magnitude and distribution of the eddy kinetic energy. The spectral results provide a technique for tracing when and where the model predictions diverge from observations

On modular signs

We consider some questions related to the signs of Hecke eigenvalues or Fourier coefficients of classical modular forms. One problem is to determine to what extent those signs, for suitable sets of primes, determine uniquely the modular form, and we give both individual and statistical results. The second problem, which has been considered by a number of authors, is to determine the size, in terms of the conductor and weight, of the first sign-change of Hecke eigenvalues. Here we improve significantly the recent estimate of Iwaniec, Kohnen and Sengupta.Comment: 23 pages, 1 figure; new version with new coauthor and strong improvements of two of the two main results

Localized large sums of random variables

We study large partial sums, localized with respect to the sums of variances, of a sequence of centered random variables. An application is given to the distribution of prime factors of typical integers.Comment: 8 pages; small changes suggested by the referee. To appear in Stat. Prob. Letter

The distribution of integers with at least two divisors in a short interval

Let H(x,y,z) be the number of integers $\le x$ with a divisor in (y,z] and let H_1(x,y,z) be the number of integers $\le x$ with exactly one such divisor. When y and z are close, it is expected that H_1(x,y,z) H(x,y,z), that is, an integer with a divisor in (y,z] usually has just one. We determine necessary and sufficient conditions on y and z so that H_1(x,y,z) H(x,y,z). In doing so, we answer an open question from the paper "The distribution of integers with a divisor in a given interval", math.NT/0401223.Comment: 12 pages; minor corrections; added abstract and affiliation informatio

Fluctuation of cognitive-emotional states during competition:an idiographic account

The purpose of this paper is to describe athletes’ cognitive-emotional processes during competitions through an idiographic and ecologically valid study method based on verbal protocols and event sequential analyses. A world-class marksman and regional-level marksman filled in an affect grid after each shot during several competitions. Verbal reports were collected after each set by a delayed retrospective recall method and compared according to perceived performance periods. Event sequential analyses were conducted. The results showed distinct interpersonal patterns of affective states fluctuations and self-regulation strategies. Furthermore, intrapersonal patterns as a function of perceived performance were also identified. We suggest that the proposed methods are useful in studying athletes’ cognitive-emotional processes during ongoing competitions, as they ensure high ecological validity and provide in-depth information for more effective, individually-tailored interventions