The Challenge of the Future

Commencement address given by D. Allan Bromley, Director of the White House Office of Science and Technology and Chair of the President's Council of Science and Technology, to the Winter 1991 graduating class of The Ohio State University, St. John Arena, Columbus, Ohio, March 22, 1991

Decreasing the uncertainty of atomic clocks via real-time noise distinguish

The environmental perturbation on atoms is the key factor restricting the performance of atomic frequency standards, especially in long term scale. In this letter, we demonstrate a real-time noise distinguish operation of atomic clocks. The operation improves the statistical uncertainty by about an order of magnitude of our fountain clock which is deteriorated previously by extra noises. The frequency offset bring by the extra noise is also corrected. The experiment proves the real-time noise distinguish operation can reduce the contribution of ambient noises and improve the uncertainty limit of atomic clocks.Comment: 5 pages, 4 figures, 1 tabl

Species and life stages of Odonata nymphs sampled with large drift nets in two Wisconsin rivers

Because relatively few nymphs of Odonata are caught in most drift studies, they have been inconsistently reported and little is known about the species and life stages that are predisposed to drift. We used large drift nets with relatively coarse mesh sizes (1500 µm) to sample late-instar odonate nymphs in two large rivers in Wisconsin. These nets were presumed to have advantages over smaller, conventional aquatic insect drift nets, including the capability to sample greater water volumes more quickly, sampling for longer periods of time before nets become clogged with debris, and a reduced likelihood of large, active insects escaping from the nets. Nymphs of 14 species of Odonata in five families were caught, but drift densities were low (0.042 m-3 overall; -3 for most species) and final instar nymphs (F-0) were collected less frequently than younger nymphs (F-1 through FOphiogomphus comprised 78% of the total in the St. Croix River. Ophiogomphus howei Bromley was the most commonly sampled species (drift density of 0.026 m-3), with at least five instars collected

Electronic properties of silica nanowires

Thin nanowires of silicon oxide were studied by pseudopotential density functional electronic structure calculations using the generalized gradient approximation. Infinite linear and zigzag Si-O chains were investigated. A wire composed of three-dimensional periodically repeated Si4O8 units was also optimized, but this structure was found to be of limited stability. The geometry, electronic structure, and Hirshfeld charges of these silicon oxide nanowires were computed. The results show that the Si-O chain is metallic, whereas the zigzag chain and the Si4O8 nanowire are insulators

Time-dependent Hartree-Fock studies of superheavy molecules

The time dependent Hartree-Fock approximation is used to study the dynamical formation of long-lived superheavy nuclear complexes. The effects of long-range Coulomb polarization are treated in terms of a classical quadrupole polarization model. Our calculations show the existence of "resonantlike" structures over a narrow range of bombarding energies near the Coulomb barrier. Calculations of 238U + 238U are presented and the consequences of these results for supercritical positron emission are discussed. NUCLEAR REACTIONS 238U + 238U collisions as a function of bombarding energy, in the time-dependent Hartree-Fock approximation. Superheavy molecules and strongly damped collisions

Teachers as leaders in a knowledge society: encouraging signs of a new professionalism

[Abstract]: Challenges confronting schools worldwide are greater than ever,and, likewise, many teachers possess capabilities, talents, and formal credentials more sophisticated than ever. However, the responsibility and authority accorded to teachers have not grown significantly, nor has the image of teaching as a profession advanced significantly. The question becomes, what are the implications for the image and status of the teaching profession as the concept of knowledge society takes a firm hold in the industrialized world? This article addresses the philosophical underpinnings of teacher leadership manifested in case studies where schools sought to achieve the generation of new knowledge as part of a process of whole-school revitalization. Specifically, this article reports on Australian research that has illuminated the work of teacher leaders engaged in the IDEAS project, a joint school revitalization initiative of the University of Southern Queensland and the Queensland Department of Education and the Arts

Substantiating a political public sphere in the Scottish press : a comparative analysis

This article uses content analysis to characterize the performance of the media in a national public sphere, by setting apart those qualities that typify internal press coverage of a political event. The article looks at the coverage of the 1999 devolved Scottish election from the day before the election until the day after. It uses a word count to measure the election material in Scottish newspapers the Herald, the Press and Journal and the Scotsman, and United Kingdom newspapers the Guardian, the Independent and The Times, and categorizes that material according to discourse type, day and page selection. The article finds a number of qualities that typify the Scottish sample in particular, and might be broadly indicative of a political public sphere in action. Firstly, and not unexpectedly, it finds that the Scottish newspapers carry significantly more election coverage. Just as tellingly, though, the article finds that the Scottish papers offer a greater proportion of advice and background information, in the form of opinion columns and feature articles. It also finds that the Scottish papers place a greater concentration of both informative and evaluative material in the period before the vote, consistent with their making a contribution to informed political action. Lastly, the article finds that the Scottish sample situates coverage nearer the front of the paper and places a greater proportion on recto pages. The article therefore argues that the Scottish papers display features that distinguish them from the UK papers, and are broadly consistent with their forming part of a deliberative public sphere, and suggests that these qualities might be explored as a means of judging future media performance

Incorporating the water footprint and virtual water into policy: reflections from the Mancha Occidental Region, Spain

Water resource management is often a controversial issue in semiarid regions. Most water resources experts admit that water conflicts are not caused by the physical water scarcity but they are mainly due to inadequate water management. The virtual water concept (the volume of water used in the production of a commodity, good or service) together with the water footprint (indicator of water consumption that looks at both direct and indirect water use of a consumer or producer), links a large range of sectors and issues, thus providing a potentially appropriate framework to support more optimal water management practices by informing production and trade decisions. This paper provides an analysis of these two concepts within the context of the Mancha Occidental region, Spain, exploring the hydrological and economic aspects of agricultural production. In doing so, this work not only distinguishes between green and blue water but also between surface and groundwater. We conclude by discussing the practical implications of the results, as well as their potential limitations from the policy standpoint