ACL: An Amazing Story

When one stops to contemplate and consider the phenomena of the Association of Christian Librarians as it celebrates the 50th year of its existence, it is nothing short of amazing! In the beginning there was a tiny band of five volunteers with a vision and passion for sharing Christian fellowship, providing access to evangelical journal literature, publishing a professional journal, and facilitating professional development amongst evangelical librarians from institutions of higher education.They had no idea what God would do with their vision, passion and hard work. No one can doubt that God has done far more than they could ever imagine or guess or request in their wildest dreams! (Eph. 3:20,The Message)

Temptation: A Biblical and Psychological Approach

Reviewed Book: Oates, Wayne Edward. Temptation: A Biblical and Psychological Approach. Louisville, Ky: Westminster/John Knox Press, 1991

Book Review

Review of: JOHN HARRIS, WONDERWOMAN AND SUPERMAN: THE ETHICS OF HUMAN BIOTECHNOLOGY. (Oxford University Press 1992) [271 pp.] Acknowledgements, further reading, index, introduction, notes. LC 91-23939; ISBN 0-19-2177540-0. [$22.95 cloth. 200 Madison Avenue; New York NY 10016.

Novel Colloidal Crystalline States on Two Dimensional Periodic Substrates

We show using numerical simulations that a rich variety of novel colloidal crystalline states are realized on square and triangular two dimensional periodic substrates which can be experimentally created using crossed laser arrays. When there are more colloids than potential substrate minima, multiple colloids are trapped at each substrate minima and act as a single particle with a rotational degree of freedom, giving rise to a new type of orientational order. We call these states colloidal molecular crystals. A two-step melting can also occur in which individual colloidal molecules initially rotate, destroying the overall orientational order, followed by the onset of inter-well colloidal hopping.Comment: 4 pages, 4 postscript figure

The Economics of Terrestrial Invasive Species: A Review of the Literature

This paper reviews the literature on the economics of invasive species management as it applies to invasive species in general and terrestrial invasive species in particular. The paper summarizes a number of recent studies that assign values to the economic impact of terrestrial invasive species on a national scale. This is followed by a review of the economic literature on control and prevention of a biological invasion and the literature on international trade and trade policy with invasive species. The paper then reviews selected studies on terrestrial invasive plants, animals, and microbes, respectively.terrestrial invasive species, prevention, control, international trade, bioeconomic, Resource /Energy Economics and Policy,

Energy, climate and water in the 21st century – Texas and Florida share a strong connection with future challenges in the Earth sciences

Bureau of Economic Geolog

A Neural Network Model for the Development of Simple and Complex Cell Receptive Fields Within Cortical Maps of Orientation and Ocular Dominance

Prenatal development of the primary visual cortex leads to simple cells with spatially distinct and oriented ON and OFF subregions. These simple cells are organized into spatial maps of orientation and ocular dominance that exhibit singularities, fractures, and linear zones. On a finer spatial scale, simple cells occur that are sensitive to similar orientations but opposite contrast polarities, and exhibit both even-symmetric and odd-symmetric receptive fields. Pooling of outputs from oppositely polarized simple cells leads to complex cells that respond to both contrast polarities. A neural network model is described which simulates how simple and complex cells self-organize starting from unsegregated and unoriented geniculocortical inputs during prenatal development. Neighboring simple cells that are sensitive to opposite contrast polarities develop from a combination of spatially short-range inhibition and high-gain recurrent habituative excitation between cells that obey membrane equations. Habituation, or depression, of synapses controls reset of cell activations both through enhanced ON responses and OFF antagonistic rebounds. Orientation and ocular dominance maps form when high-gain medium-range recurrent excitation and long-range inhibition interact with the short-range mechanisms. The resulting structure clarifies how simple and complex cells contribute to perceptual processes such as texture segregation and perceptual grouping.Air Force Office of Scientific Research (F49620-92-J-0334); British Petroleum (BP 89A-1204); National Science Foundation (IRI-90-24877); Office of Naval Research (N00014-91-J-4100); Defense Advanced Research Projects Agency and the Office of Naval Research (N00014-95-1-0409

Commensurability Effects at Nonmatching Fields for Vortices in Diluted Periodic Pinning Arrays

Using numerical simulations, we demonstrate that superconductors containing periodic pinning arrays which have been diluted through random removal of a fraction of the pins have pronounced commensurability effects at the same magnetic field strength as undiluted pinning arrays. The commensuration can occur at fields significantly higher than the matching field, produces much greater critical current enhancement than a random pinning arrangement due to suppresion of vortex channeling, and persists for arrays with up to 90% dilution. These results suggest that diluted periodic pinning arrays may be a promising geometry to increase the critical current in superconductors over a wide magnetic field range.Comment: 6 pages, 5 postscript figures. Version to appear in Phys. Rev.