The effect of beam-driven return current instability on solar hard X-ray bursts

The problem of electrostatic wave generation by a return current driven by a small area electron beam during solar hard X-ray bursts is discussed. The marginal stability method is used to solve numerically the electron and ion heating equations for a prescribed beam current evolution. When ion-acoustic waves are considered, the method appears satisfactory and, following an initial phase of Coulomb resistivity in which T sub e/T sub i rise, predicts a rapid heating of substantial plasma volumes by anomalous ohmic dissipation. This hot plasma emits so much thermal bremsstrahlung that, contrary to previous expectations, the unstable beam-plasma system actually emits more hard X-rays than does the beam in the purely collisional thick target regime relevant to larger injection areas. Inclusion of ion-cyclotron waves results in ion-acoustic wave onset at lower T sub e/T sub i and a marginal stability treatment yields unphysical results

General purpose film plotting system

The general purpose film plotting system which is a plot program design to handle a majority of the data tape formats presently available under OS/360 was discussed. The convenience of this program is due to the fact that the user merely describes the format of his data set and the type of data plots he desires. It processes the input data according to the given specifications. The output is generated on a tape which yields data plots when processed by the selected plotter. A summary of each job is produced on the printer

Sur le lemme de Brody

Brody's lemma is a basic tool in complex hyperbolicity. We present a version of it making more precise the localization of an entire curve coming from a diverging sequence of holomorphic discs. As a byproduct we characterize hyperbolicity in terms of an isoperimetric inequality

Are Biological Science Knowledge, Interests, and Science Identity Framed by Religious and Political Perspectives in the United States?

Science trust and views of science differ by political and religious orientations. In this study we examine whether political and religious perspectives are also associated with biological science knowledge, science interest, and general science identity. Results show that conservative Protestants have lower biological science knowledge than other religious groups on several specific topics. Party affiliation is associated with vaccine knowledge but not science interest and identity. Adjusting for demographic characteristics explains some political and religious group differences, but not all. We discuss implications regarding attention to potential political and religious framings of science topics in public education efforts

Decline Is Not Inevitable: Changes in Science Identity during the Progression through a U.S. Middle School among Boys and Girls

In the United States, science capital is important for navigating many aspects of life. Yet during middle school, science interest declines more for girls than boys. It is unclear, however, whether science identity also declines during the middle school years and if there are differences by gender. The authors advance prior research by modeling changes in science identity and associations with changes in identity-relevant characteristics using growth curve analyses on four waves of data from 760 middle school youth. For girls and boys, science identity changes over time; about 40 percent of the variance is within-person change, with the remainder explained by aggregate between-person differences. The associations of all identity-relevant characteristics with science identity are not significantly different for girls and boys, yet declines in average values of identity-relevant characteristics are larger for girls than boys

On the Shuffle Automaton Size for Words

We investigate the state size of DFAs accepting the shuffle of two words. We provide words u and v, such that the minimal DFA for u shuffled with v requires an exponential number of states. We also show some conditions for the words u and v which ensure a quadratic upper bound on the state size of u shuffled with v. Moreover, switching only two letters within one of u or v is enough to trigger the change from quadratic to exponential