Review of \u3ci\u3eEdmonton: The Life of a City\u3c/i\u3e Edited by Bob Hesketh and Frances Swyripa

The essays in Edmonton: The Life of a City were first presented at a conference at the University of Alberta in May of 1995. They have been brought together here to celebrate the past in the bicentennial life of what the editors call (but do not fully investigate) a great northern city. Offered up by both professional and amateur scholars alike, including -among others-historians and geographers, architects and archivists, literature specialists and political scientists, this diversified collection comprises over thirty well-written chapters. Taken as a whole, they offer a multidisciplinary interpretation of the evolving history of Alberta\u27s largest populated city, now approaching the one million mark. The essays range across a great deal of time, from the city\u27s early fur trading and shortlived coal mining days to the more recent past and questions about its economic, political, and cultural fortunes. They also cover considerable terrain. For example, the chapter by Peter Smith on the physical expansion of Edmonton\u27s post-war residential areas is a reasoned synthesis of the many planning issues that confronted urban planners when the city, immediately following the discovery of oil nearby at Leduc in 1947, grew by explosive leaps and bounds. This macro approach to the urban landscape is nicely balanced by concern for individuals-architects, politicians, and other community leaders-who actually designed, built, and governed the city. We learn, for example, in well-contextualized studies, of Les Girls, the architectural team of Jean Wallbridge and Mary Imrie, as well as Harry Evans, the Squire of Sylvancroft, and Elmer Roper, socialist, businessman, and mayor. The book also provides a strong sense of the multicultural dimensions of Edmonton\u27s varied population (Cree, Chinese, English, and Ukrainian among others), but here one wishes for a contextual chapter assessing the changing demographic and ethnic composition of the city\u27s population. This would have offered further help to the reader considering the several chapters on various aspects of the city\u27s religious life. Nonetheless, most chapters- whether dealing with youth, Native issues, returning war veterans, the theater, regulating urban markets, or nursing the sick-are handled deftly and support the growing trend of blending a comprehensive range of topics with the more obvious economic and political tales when writing the general urban history of Canada. But if the larger context is at times shunned, this is more than compensated for in two principal ways. First, the book is framed by a thoughtful, personal introduction by Gilbert Stelter and a suggestive, summary statement by Paul Voisey, two of Canada\u27s most provocative urban historians. The richness of their chapters and the carefully considered multidisciplinary case studies give the reader a wide range of topics, themes, and disciplinary perspectives to ponder and consider. And second, to support the task of pondering and considering, the book is thoroughly illustrated with carefully chosen and well-captioned photographs and maps that add depth, clarity, and interest to the interpretation of Edmonton\u27s multi-faceted growth and change. Edmonton: The Life of a City provides reasoned arguments about many strands of the evolving economic, social, and cultural history of this important western Canadian city. While not a complete history-and it makes no claim to be comprehensive-the multidisciplinary approach, focusing on urban history, is certainly the book\u27s principal strength. That the volume is generally successful is the result of the sharp editing and dedicated sense of purpose that editors Bob Hesketh and Frances Swyripa, as well as their contributors, brought both to the conference and to this collection

An LED-based Flasher System for VERITAS

We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along with measurements made with a prototype mounted on one of the VERITAS telescopes.Comment: Accepted for publication in Nuclear Instruments and Methods in Physics Research

Universality in escape from a modulated potential well

We show that the rate of activated escape $W$ from a periodically modulated potential displays scaling behavior versus modulation amplitude $A$. For adiabatic modulation of an optically trapped Brownian particle, measurements yield $\ln W\propto (A_{\rm c} - A)^{\mu}$ with $\mu = 1.5$. The theory gives $\mu=3/2$ in the adiabatic limit and predicts a crossover to $\mu=2$ scaling as $A$ approaches the bifurcation point where the metastable state disappears.Comment: 4 pages, 3 figure

Ultracold, radiative charge transfer in hybrid Yb ion - Rb atom traps

Ultracold hybrid ion-atom traps offer the possibility of microscopic manipulation of quantum coherences in the gas using the ion as a probe. However, inelastic processes, particularly charge transfer can be a significant process of ion loss and has been measured experimentally for the Yb$^{+}$ ion immersed in a Rb vapour. We use first-principles quantum chemistry codes to obtain the potential energy curves and dipole moments for the lowest-lying energy states of this complex. Calculations for the radiative decay processes cross sections and rate coefficients are presented for the total decay processes. Comparing the semi-classical Langevin approximation with the quantum approach, we find it provides a very good estimate of the background at higher energies. The results demonstrate that radiative decay mechanisms are important over the energy and temperature region considered. In fact, the Langevin process of ion-atom collisions dominates cold ion-atom collisions. For spin dependent processes \cite{kohl13} the anisotropic magnetic dipole-dipole interaction and the second-order spin-orbit coupling can play important roles, inducing couplingbetween the spin and the orbital motion. They measured the spin-relaxing collision rate to be approximately 5 orders of magnitude higher than the charge-exchange collision rate \cite{kohl13}. Regarding the measured radiative charge transfer collision rate, we find that our calculation is in very good agreement with experiment and with previous calculations. Nonetheless, we find no broad resonances features that might underly a strong isotope effect. In conclusion, we find, in agreement with previous theory that the isotope anomaly observed in experiment remains an open question.Comment: 7 figures, 1 table accepted for publication in J. Phys. B: At. Mol. Opt. Phys. arXiv admin note: text overlap with arXiv:1107.114

Recovering Information Worth Knowing: Developing More Discriminating Approaches for Selecting Nineteenth-Century Rural Domestic Sites and Farmsteads

This article examines the difficulties faced by one state agency (NYSDOT) when the primary focus of a cultural resource survey program shifts from managing rare and clearly significant archaeological sites to a cultural resource survey program that addresses the more commonly found historical archaeological sites associated with mid to late 19th-century farmsteads and rural domestic sites. It encourages a critical review of cultural resource survey results in order to develop meaningful and effective selection criteria for deciding how limited public funds should be allocated for cultural resource surveys

Doppler cooling of gallium atoms: 2. Simulation in complex multilevel systems

This paper derives a general procedure for the numerical solution of the Lindblad equations that govern the coherences arising from multicoloured light interacting with a multilevel system. A systematic approach to finding the conservative and dissipative terms is derived and applied to the laser cooling of gallium. An improved numerical method is developed to solve the time-dependent master equation and results are presented for transient cooling processes. The method is significantly more robust, efficient and accurate than the standard method and can be applied to a broad range of atomic and molecular systems. Radiation pressure forces and the formation of dynamic dark-states are studied in the gallium isotope 66Ga.Comment: 15 pages, 8 figure

Strong-field approximation for Coulomb explosion of H_2^+ by short intense laser pulses

We present a simple quantum mechanical model to describe Coulomb explosion of H$_2^+$ by short, intense, infrared laser pulses. The model is based on the length gauge version of the molecular strong-field approximation and is valid for pulses shorter than 50 fs where the process of dissociation prior to ionization is negligible. The results are compared with recent experimental results for the proton energy spectrum [I. Ben-Itzhak et al., Phys. Rev. Lett. 95, 073002 (2005), B. D. Esry et al., Phys. Rev. Lett. 97, 013003 (2006)]. The predictions of the model reproduce the profile of the spectrum although the peak energy is slightly lower than the observations. For comparison, we also present results obtained by two different tunneling models for this process.Comment: 8 pages, 4 figure