Climate Change and Great Lakes Water Resources

Looks at how climate change will impact water resources in the Great Lakes region and identifies policies to reduce greenhouse gas emissions that cause climate change

Experimental verification and practical application of torquewhirl theory of rotordynamic instability

A theory developed by Vance in 1978 to explain the destabilizing effect of torque on a whirling rotor was experimentally verified. The measurements made on a specially designed test apparatus are described. New computer models were also developed to investigate the effect of torque on rotordynamic stability of multidisk flexible rotor bearing systems. The effect of torque was found to be most pronounced when the system is already marginally stable from other influences. The modifications required to include torque in a typical shaft transfer matrix are described, and results are shown which identify the type of rotor design most sensitive to load torque

Do Tender Offers Create Value? New Methods and Evidence

We develop the Probability Scaling Method, which rescales short-window announcement period returns; and the Intervention Method, which uses returns associated with intervening events, to estimate value improvements from tender offers. These methods address biases in conventional techniques, which measure only a fraction of the total tender offer gain; and which include revelation about bidder stand-alone value. Perceived value improvements are much larger than traditional methods indicate, so that we cannot reject the hypothesis that bidders on average pay fair prices for targets. Furthermore, our new methods affect inferences about economic forces in the takeover market. We identify several effects (higher combined bidder-target stock returns for hostile offers, lower for equity offers, and lower for diversifying offers) that reflect differences in revelation about stand-alone value, not gains from combination.Tender offers, value improvements, truncation dilemma, revelation bias, agency

Groups Reactions to Failure: A Social Identity Approach

This experiment examined how people react after their group has failed at a task. One-hundred thirteen female participants were randomly placed in three-person groups and asked to complete an aesthetic judgment task similar to that used by Klein (1997). All participants then received (false) feedback showing that their group had failed on the task, with many participants also receiving individual feedback about their performance. Some participants were told they performed better than the other members of their group, some were told they did worse, and the rest received no individual feedback. Half of the participants were also told they would lead their group, if it performed the task again, whereas others were told that another member would lead the group. Participants were then asked to choose between trying the same task again, or a taking chance option to win a cash prize. Social identity theory suggests that individuals who "performed" better than other group members, and were also selected as leader, might try to enhance their personal and social identities by choosing to do the same task again. In contrast, individuals who "performed" worse, and were selected as leader, would be less likely to choose to do the task again. Results showed simply that those who performed better were more likely than those who performed worse to try the task again. The leadership variable showed no significant effects

Star Formation in Dwarf Galaxies

We explore mechanisms for the regulation of star formation in dwarf galaxies. We concentrate primarily on a sample in the Virgo cluster, which has HI and blue total photometry, for which we collected H$\alpha$ data at the Wise Observatory. We find that dwarf galaxies do not show the tight correlation of the surface brightness of H$\alpha$ (a star formation indicator) with the HI surface density, or with the ratio of this density to a dynamical timescale, as found for large disk or starburst galaxies. On the other hand, we find the strongest correlation to be with the average blue surface brightness, indicating the presence of a mechanism regulating the star formation by the older (up to 1 Gyr) stellar population if present, or by the stellar population already formed in the present burst.Comment: 15 pages (LATEX aasms4 style) and three postscript figures, accepted for publication in the Astrophysical Journa

Genetic Counseling in Retinitis Pigmentosa

During his lifetime the practicing ophthalmologist will see more than a few retinitis pigmentosa cases. It is his responsibility not only to diagnose and prognosticate this eye disease, but also to set aside a little time in which to advise the patient and his family on its genetic aspects