Cowbane, Oxypolis occidentalis, A New Native Vascular Plant Species for the Queen Charlotte Islands, British Columbia

We report the recent discovery of Oxypolis occidentalis, a species that is new to both British Columbia and Canada, disjunct on the Queen Charlotte Islands

The fundamental solution of the unidirectional pulse propagation equation

The fundamental solution of a variant of the three-dimensional wave equation known as "unidirectional pulse propagation equation" (UPPE) and its paraxial approximation is obtained. It is shown that the fundamental solution can be presented as a projection of a fundamental solution of the wave equation to some functional subspace. We discuss the degree of equivalence of the UPPE and the wave equation in this respect. In particular, we show that the UPPE, in contrast to the common belief, describes wave propagation in both longitudinal and temporal directions, and, thereby, its fundamental solution possesses a non-causal character.Comment: accepted to J. Math. Phy

PRODUCTIVITY AND THE ENACTMENT OF A MACRO CULTURE

This paper reports the puzzling results of a study which examined IT capital investment and productivity at three of the largest IT user sites in the U.S. for the period 1970-1990: Social Security Administration (SSA), Internal Revenue Service (IRS), and the Federal Bureau of Investigation (FBI). Based on detailed IT investment, employment, and output data over twenty years, we found that only one agency had achieved significant productivity benefits, a second agency had modest results, and a third agency achieved no results whatever. These results cannot be explained by traditional theories of productivity of how productivity is produced. We argue that IT-induced productivity results not simply from strategic choice, nor the operation of the invisible hand in the market place, nor simply from keen managers adjusting their organizations to an "objective" environment. Instead we propose instead a new theory in which productivity benefits derive from a larger macro-culture enacted by powerful institutions in an organizational field. We extend this analysis to the larger economy and examine how this new theory helps us understand recent claims that IT is finally having positive productivity benefits at the sector level, and also helps us understand how the current fascination with reengineering and downsizing may be a self-fulfilling prophecy.Information Systems Working Papers Serie

The Effect of Particle Strength on the Ballistic Resistance of Shear Thickening Fluids

The response of shear thickening fluids (STFs) under ballistic impact has received considerable attention due to its field-responsive nature. While efforts have primarily focused on the response of traditional ballistic fabrics impregnated with fluids, the response of pure STFs to penetration has received limited attention. In the present study, the ballistic response of pure STFs is investigated and the effect of fluid density and particle strength on ballistic performance is isolated. The loss of ballistic resistance of STFs at higher impact velocities is governed by particle strength, indicating the range of velocities over which they may provide effective armor solutions.Comment: 4 pages, 4 figure

Information Technology and Occupational Structure

A central tenet of much popular and scholarly literature is that computers -and more broadly speaking "information systems"- bring about significant change in organizations. Some scholars focus on changes in organizational structure- the division of labor and its coordination through authority and power (Blau, 1976; Danziger, et. d., 1982; Laudon, 1976; 1986; Keen 1981; Kling and Iacono, 1984; Orlikowski and Robey, 1991; Robey, 1981; Walton, 1989; Barley 1986; 1990) . Others focus on IT induced changes in the design of work (Zuboff, 1984; Bikson, et. al., 1985: Kraut, et. al., 1987; Sproull and Kiesler, 199 1; Turner, 1984; Iacono and Kling, 1987). Still others have argued that IT significantly alters occupational structure in organizations--the distribution of employment among occupations and skill classes of workers (Braverman, 1984; Kling and Turner, 1987; Berndt, et. al., 1992; Howell and W e , 1993; Cyert and Mowry, 1988; 1989). In general, the impact of IT on occupational structure of firms and organizations is a neglected area of empirical research despite the fact that scholars have strong opinions, and convincing theories, about such occupational shifts. In this paper we report the results of a twenty year longitudinal study of occupational structure in three of the largest and most intensive organizational users of IT in the United States. For benchmarking purposes we also examine occupational change at the aggregate society level and in the federal government sector over a twenty year period. The results of our research question the claim that IT brings about significant change in occupational structure. While the organizations we examine did experience significant change in occupational structure during periods of intense computerization, these changes did not conform to theoretical predictions and they were inconsistent from one organization to another. We conc1ude that organizational occupational structures are quite stable in the face of massive IT change and claims that IT brings about "revo1utionaryâ changes in organizational structure have little empirical foundation even though there may be isolated cases where such rapid and drastic changes do occur.Information Systems Working Papers Serie

Capturing Genetic Variation during Ecological Restorations: An Example from Kankakee Sands in Indiana

Genetic variation in populations, both natural and restored, is usually considered crucial for response to short term environmental stresses and for long term evolutionary change. To have the best chance of successful long-term survival, restored populations should reflect the extant variation found in remnants, but restored sites may suffer from genetic bottlenecks as a result of founder effects. Kankakee Sands is a large-scale restoration being conducted by The Nature Conservancy (TNC) in northwestern Indiana. Our goal was to test for loss of genetic variation in restored plant populations by comparing them with TNC’s seed source nursery and with local remnant populations that were the source of nursery seed and of the first few restored sites. Allozyme analysis of Baptisia leucantha, Asclepias incarnata, Coreopsis tripteris, and Zizia aurea showed low levels of allozyme diversity within all species and reductions in polymorphism, alleles per locus, and expected heterozygosity between remnants and restorations for all species except A. incarnata. Almost all lost alleles were rare; restored populations contained almost 90% of alleles at polymorphic loci that occurred in remnants at frequencies greater than one percent. Allele frequencies for most loci did not differ between remnants and restored sites. Most species showed significant allele frequency differentiation among remnant populations and among restored sites. Our results indicate that seed collection techniques used at Kankakee Sands captured the great majority of allozyme variation present in seed source remnant populations

MANAGEMENT STRATEGY, INVESTMENT IN IT, AND PRODUCTIVITY

Previous literature on IT and productivity does not take into account different organizational goals and different management strategies for achieving these goals. But productivity and ROI relationships can easily differ as organizational goals and management strategies differ. Therefore, we argue, it is no longer appropriate to ask, "Does IT lead to productivity enhancement." or "Is the ROI on IT investments large or small or nonexistent? The better question is under what conditions of organizational climate and management choice does IT enhanced productivity result. To illustrate the powerful effect of organizational goals and management strategy on IT-productivity relationships, we examine the twenty year history of two of the largest IT users in the world: the Internal Revenue Service and the Social Security Administration. And we find that these two very similar agencies experienced very different results from massive investments in IT despite sharing a similar production function. There is nothing in micro economics however to explain the different strategies pursed by these managers. Instead we must turn to political and sociological models of organizations to understand the social construction of productivity results.Information Systems Working Papers Serie

A third update of the status of the 3CR sources - Further new redshifts and new identifications of distant galaxies

We present the third major update of new optical and radio data for the strong sources in the Revised Third Cambridge Catalogue (hereafter 3CR). New positions, redshifts, magnitudes, and identifications have been included as well as some radio data for the sample of 298 extragalactic 3CR sources. A new and extended bibliography of optical and radio data is included. The 3CR sources have now reached an almost satisfactory state of optical identification; 91% of the sources at midbmid > 10° now have firm identifications and we have spectra for most of them. The few remaining faint objects at high latitudes are, of course, important, as they tend to be the most luminous radio sources known. Full completion of the 3CR data will aid in reducing the residual uncertainties at the luminous end of the evolving radio luminosity ftinction. Finally, we present some new identifications and new spectroscopic data for 29 faint 3CR galaxies, and one quasar

Direct calculation of the hard-sphere crystal/melt interfacial free energy

We present a direct calculation by molecular-dynamics computer simulation of the crystal/melt interfacial free energy, $\gamma$, for a system of hard spheres of diameter $\sigma$. The calculation is performed by thermodynamic integration along a reversible path defined by cleaving, using specially constructed movable hard-sphere walls, separate bulk crystal and fluid systems, which are then merged to form an interface. We find the interfacial free energy to be slightly anisotropic with $\gamma$ = 0.62$\pm 0.01$, 0.64$\pm 0.01$ and 0.58$\pm 0.01 k_BT/\sigma^2$ for the (100), (110) and (111) fcc crystal/fluid interfaces, respectively. These values are consistent with earlier density functional calculations and recent experiments measuring the crystal nucleation rates from colloidal fluids of polystyrene spheres that have been interpreted [Marr and Gast, Langmuir {\bf 10}, 1348 (1994)] to give an estimate of $\gamma$ for the hard-sphere system of $0.55 \pm 0.02 k_BT/\sigma^2$, slightly lower than the directly determined value reported here.Comment: 4 pages, 4 figures, submitted to Physical Review Letter