Dynamical models for sand ripples beneath surface waves

We introduce order parameter models for describing the dynamics of sand ripple patterns under oscillatory flow. A crucial ingredient of these models is the mass transport between adjacent ripples, which we obtain from detailed numerical simulations for a range of ripple sizes. Using this mass transport function, our models predict the existence of a stable band of wavenumbers limited by secondary instabilities. Small ripples coarsen in our models and this process leads to a sharply selected final wavenumber, in agreement with experimental observations.Comment: 9 pages. Shortened version of previous submissio

The Career Decisions of Gifted Students: An Asian-Pacific Perspective

Drawing on the literature in multiple related areas, an overview is presented in this chapter of the major issues that may surround career decisions for gifted students in the Asia-Pacific region. After a discussion on the pervasive role of family influence reflecting cultural values in the region, coverage is given to the importance placed on extrinsic values such as prestige, economic returns, and stability in a career (and the lack of emphasis on intrinsic values such as interest and a desire for intellectual stimulation), along with gender role expectations and the experience of career indecision. Thereafter, the similarities and differences in the career aspirations of gifted students in the region with the career aspirations of gifted students in Western societies are explained. Following this, two career theories that may be useful in understanding the career decisions of this group—the theory of circumscription and compromise and the theory of work adjustment—are discussed. The chapter concludes with some speculative, but research-informed, thoughts on the future of the career decisions of gifted students in the region

A Study of the Guidance Program at Biwabik, Minnesota and Recommendations for Its Improvement

A Paper Presented to the Faculty of the Graduate School, University of Minnesota, A Requirement for the Degree Master of Arts (Plan B), by Fred D. Lofquist, June 1956.Lofquist, Fred D. (1956). A Study of the Guidance Program at Biwabik, Minnesota and Recommendations for Its Improvement. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/229719

A discrete region centered 22 base pairs upstream of the initiation site modulates transcription of Drosophila tRNAAsn genes.

We have studied the mechanism by which 5'-flanking sequences modulate the in vitro transcription of eucaryotic tRNA genes. Using deletion and linker substitution mutagenesis, we have found that the 5'-flanking sequences responsible for the different in vitro transcription levels of three Drosophila tRNA5Asn genes are contained within a discrete region centered 22 nucleotides upstream from the transcription initiation site. In conjunction with the A-box intragenic control region, this upstream transcription-modulatory region functions in the selection mechanism for the site of transcription initiation. Since the transcription-modulatory region directs the position of the start site and the actual sequence of the transcription-modulatory region determines the level of tRNAAsn gene transcription, the possibility is raised that the transcription-modulatory region directs a transcription initiation event similar to open complex formation at procaryotic promoters