The Epidemiology of Skin Cancer in Queensland: The Significance of Premalignant Conditions

Data are presented for four cities in Quensland that show that there is a tendency for both basal and squamous cell cancer to occur in the absence of hyperkeratosis. The converse also holds. The anatomical distribution of the keratoses does not follow that of one particular form of cancer, but roughly that of both, although basal cell cancers and hyperkeratoses are not likely to be confused clinically. It seems that solar keratosis is not an important premalignant lesion, but rather that it occurs independently. In this, as in the preceding paper on the incidence of skin cancer, it must be stressed that geographical factors are specially important, and that what is true for Queensland is not necessarily true for other regions further from the Equator. This work was carried out during the tenure of a Medical Research Fellowship at the University of Queensland. I would like to acknowledge the advice and help of Dr. A. G. S. Cooper, Director of the Queensland Radium Institute

The Epidemiology of Skin Cancer in Queensland: The Incidence

The age specific incidence rates of skin cancer in four coastal cities in Queensland are calculated and discussed. On the assumption that ultraviolet radiation is the causative factor, it is suggested that the only difference in response to the stimulus by the four populations is one of frequency of incidence. This arises from the observation that the curves are parallel for each of the four cities. Several methods of fitting lines to the data are described. This investigation was carried out while one of us held a Medical Research Fellowship at the University of Queensland. We are indebted to Dr. A. G. S. Cooper, Director of the Queensland Radium Institute, who allowed free use of the records of the Institute, and who helped with the numerous problems that arose during the course of the survey

Principles of War and Their Application to Strategy and Tactics

The task of the Naval War College mission is to further an understanding of the fundamentals of warfare, with. emphasis on their application to future naval warfare. Accordingly, it is my purpose this morning to examine some of the fundamental truths of war and to indicate how these so-called principles of war are ap­plicable to strategy and tactics

Plague Persistence in Western Europe: A Hypothesis

Historical sources documenting recurrent plagues of the “Second Pandemic” usually focus on urban epidemic mortality. Instead, plague persists in remote, rural hinterlands: areas less visible in the written sources of late medieval Europe. Plague spreads as fleas move from relatively resistant rodents, which serve as “maintenance hosts,” to an array of more susceptible rural mammals, now called “amplifying hosts.” Using sources relevant to plague in thinly populated Central and Western Alpine regions, this paper postulates that Alpine Europe could have been a region of plague persistence via its population of wild rodents, particularly the Alpine marmot

Multiple-time correlation functions for non-Markovian interaction: Beyond the Quantum Regression Theorem

Multiple time correlation functions are found in the dynamical description of different phenomena. They encode and describe the fluctuations of the dynamical variables of a system. In this paper we formulate a theory of non-Markovian multiple-time correlation functions (MTCF) for a wide class of systems. We derive the dynamical equation of the {\it reduced propagator}, an object that evolve state vectors of the system conditioned to the dynamics of its environment, which is not necessarily at the vacuum state at the initial time. Such reduced propagator is the essential piece to obtain multiple-time correlation functions. An average over the different environmental histories of the reduced propagator permits us to obtain the evolution equations of the multiple-time correlation functions. We also study the evolution of MTCF within the weak coupling limit and it is shown that the multiple-time correlation function of some observables satisfy the Quantum Regression Theorem (QRT), whereas other correlations do not. We set the conditions under which the correlations satisfy the QRT. We illustrate the theory in two different cases; first, solving an exact model for which the MTCF are explicitly given, and second, presenting the results of a numerical integration for a system coupled with a dissipative environment through a non-diagonal interaction.Comment: Submitted (04 Jul 04

Nonlinear photon transport in a semiconductor waveguide-cavity system containing a single quantum dot: Anharmonic cavity-QED regime

We present a semiconductor master equation technique to study the input/output characteristics of coherent photon transport in a semiconductor waveguide-cavity system containing a single quantum dot. We use this approach to investigate the effects of photon propagation and anharmonic cavity-QED for various dot-cavity interaction strengths, including weakly-coupled, intermediately-coupled, and strongly-coupled regimes. We demonstrate that for mean photon numbers much less than 0.1, the commonly adopted weak excitation (single quantum) approximation breaks down, even in the weak coupling regime. As a measure of the anharmonic multiphoton-correlations, we compute the Fano factor and the correlation error associated with making a semiclassical approximation. We also explore the role of electron--acoustic-phonon scattering and find that phonon-mediated scattering plays a qualitatively important role on the light propagation characteristics. As an application of the theory, we simulate a conditional phase gate at a phonon bath temperature of $20$K in the strong coupling regime.Comment: To appear in PR

Atom detection in a two-mode optical cavity with intermediate coupling: Autocorrelation studies

We use an optical cavity in the regime of intermediate coupling between atom and cavity mode to detect single moving atoms. Degenerate polarization modes allow excitation of the atoms in one mode and collection of spontaneous emission in the other, while keeping separate the two sources of light; we obtain a higher confidence and efficiency of detection by adding cavity-enhanced Faraday rotation. Both methods greatly benefit from coincidence detection of photons, attaining fidelities in excess of 99% in less than 1 microsecond. Detailed studies of the second-order intensity autocorrelation function of light from the signal mode reveal evidence of antibunched photon emissions and the dynamics of single-atom transits.Comment: 10 pages, 10 figures, to be published in Phys. Rev.