Effects of a negative social experience on the emotional and social-cognitive responses of aggressive-rejected children.

Social problem-solving skills of aggressive-rejected children are usually assessed through hypothetical situations in a neutral setting where little or no reference is made to the emotional aspects. The aim of this study was to evaluate the social problem-solving skills of 57 aggressive-rejected (Group 1) and 57 prosocial-popular (Group 2) children of both sexes in Grades 1 and 2 by using as problem situations what happened in standardized provocations involving them with a trained peer-accomplice. An individual interview, aimed at disclosing emotions felt during the provocations, intentions attributed to the accomplice and possible reactions if confronted again with the same provocations, was conducted immediately after the session for half the subjects of each group. The other subjects were interviewed after a 10-min. delay. Analysis showed that Group 1 subjects would be less verbally assertive than Group 2 subjects if confronted again with the same provocations. The first graders from Group 1 also attributed fewer positive intents to the author of the provocations than Group 2 classmates. Second graders of both groups attributed more negative and fewer positive intents to the peer-accomplice when the interview immediately followed the provocations than when it was delayed. Similarly, second grade boys interviewed right away were more prone to use physical and verbal retaliation if the provocations were to happen again. These results highlight the influence of emotions on the social reasoning skills of aggressive-rejected and nonaggressive-nonrejected children.

New measurement of the cosmic-ray positron fraction from 5 to 15 GeV.

We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-pbar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of nonstandard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e(+/-) instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV.

Measurement of the cosmic-ray antiproton-to-proton abundance ratio between 4 and 50 GeV.

We present a new measurement of the antiproton-to-proton abundance ratio, pbar/p, in the cosmic radiation. The HEAT-pbar instrument, a balloon borne magnet spectrometer with precise rigidity and multiple energy loss measurement capability, was flown successfully in Spring 2000, at an average atmospheric depth of 7.2 g/cm(2). A total of 71 antiprotons were identified above the vertical geomagnetic cutoff rigidity of 4.2 GV. The highest measured proton energy was 81 GeV. We find that the pbar/p abundance ratio agrees with that expected from a purely secondary origin of antiprotons produced by primary protons with a standard soft energy spectrum.