Radon and skin cancer in southwest England: an ecologic study

This is the author's post peer review version of the article. The final version is published in Epidemiology. 2012 Jan;23(1):44-52. doi: 10.1097/EDE.0b013e31823b6139.Radon, a naturally occurring radioactive gas, is a carcinogen that causes a small proportion of lung cancers among exposed populations. Theoretical models suggest that radon may also be a risk factor for skin cancer, but epidemiologic evidence for this relationship is weak. In this study, we investigated ecologic associations between environmental radon concentration and the incidence of various types of skin cancer

The Effects of Authentic Leadership on Individual Occupational Well-Being

Leaders play a critical role in an organization, and their presence and behavior significantly affect nonmanagement employee work performance, behavior, and well-being. Authentic leadership has a positive effect on an organization. The problem was nonmanagement employees spend so much time at work and desire meaningful experiences and relationships during the workday to counter feelings of uncertainty and a lack of job satisfaction. The purpose of this transcendental phenomenological study was to identify and report the lived experiences of nonmanagerial employees of the architect, engineer, and construction (AEC) industry located in the Northeastern United States about work-related well-being defined as people’s feelings about themselves concerning their job. Authentic leadership theory was used to explore a leader’s purpose, values, relationships, self-discipline, and heart in a practical approach to authentic leadership. The research question was about the meaning of experiencing occupational well-being ascribed to by nonmanagement employees. I interviewed 22 participants during my fieldwork in one-on-one qualitative interviews and used manual and automated data analysis to provide patterns, themes, interpretations, and assertions. Key findings included a sense of community, encouragement to grow, feeling secure in my job, being technically proficient, feeling valued, connecting daily, feeling like I belong, being fair in their decisions, enjoying coming to work, and facilitating work-life balance. The potential for positive social change is unlimited, with a better understanding of leadership effects on occupational well-being, thus benefiting management, employees, and customers

Mixed and galerkin finite element approximation of flow in a linear viscoelastic porous medium

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2013 ElsevierThis article has been made available through the Brunel Open Access Publishing Fund.We propose two fully discrete mixed and Galerkin finite element approximations to a system of equations describing the slow flow of a slightly compressible single phase fluid in a viscoelastic porous medium. One of our schemes is the natural one for the backward Euler time discretization but, due to the viscoelasticity, seems to be stable only for small enough time steps. The other scheme contains a lagged term in the viscous stress and pressure evolution equations and this is enough to prove unconditional stability. For this lagged scheme we prove an optimal order a priori error estimate under ideal regularity assumptions and demonstrate the convergence rates by using a model problem with a manufactured solution. The model and numerical scheme that we present are a natural extension to ‘poroviscoelasticity’ of the poroelasticity equations and scheme studied by Philips and Wheeler in (for example) [Philip Joseph Philips, Mary F.Wheeler, Comput. Geosci. 11 (2007) 145–158] although — importantly — their algorithms and codes would need only minor modifications in order to include the viscous effects. The equations and algorithms presented here have application to oil reservoir simulations and also to the condition of hydrocephalus — ‘water on the brain’. An illustrative example is given demonstrating that even small viscoelastic effects can produce noticeable differences in long-time response. To the best of our knowledge this is the first time a mixed and Galerkin scheme has been analysed and implemented for viscoelastic porous media

Entropy and the cosmological constant: a spacetime-foam approach

A simple model of spacetime foam, made by N wormholes in a semiclassical approximation, is taken under examination. The Casimir-like energy of the quantum fluctuation of such a model and its probability of being realized are computed. Implications on the Bekenstein-Hawking entropy and the cosmological constant are considered.Comment: LaTeX file uses espcrc2.sty, 4 pages. Talk given at the Third Meeting on Constrained Dynamics and Quantum Gravity, Villasimius (Sardinia), September 13-17, 1999. New Reference include

Relativistic non-instantaneous action-at-a-distance interactions

Relativistic action-at-a-distance theories with interactions that propagate at the speed of light in vacuum are investigated. We consider the most general action depending on the velocities and relative positions of the particles. The Poincare invariant parameters that label successive events along the world lines can be identified with the proper times of the particles provided that certain conditions are impossed on the interaction terms in the action. Further conditions on the interaction terms arise from the requirement that mass be a scalar. A generic class of theories with interactions that satisfy these conditions is found. The relativistic equations of motion for these theories are presented. We obtain exact circular orbits solutions of the relativistic one-body problem. The exact relativistic one-body Hamiltonian is also derived. The theory has three components: a linearly rising potential, a Coulomb-like interaction and a dynamical component to the Poincar\'e invariant mass. At the quantum level we obtain the generalized Klein-Gordon-Fock equation and the Dirac equation

Global solution to the Allen-Cahn equation with singular potentials and dynamic boundary conditions

We prove well-posedness results for the solution to an initial and boundary-value problem for an Allen-Cahn type equation describing the phenomenon of phase transitions for a material contained in a bounded and regular domain. The dynamic boundary conditions for the order parameter have been recently proposed by some physicists to account for interactions with the walls. We show our results using suitable regularizations of the nonlinearities of the problem and performing some a priori estimates which allow us to pass to the limit thanks to compactness and monotonicity arguments.Comment: Key words: Allen-Cahn equation, dynamic boundary conditions, maximal monotone graphs, initial boundary value problem, existence and uniqueness result

The American Psychiatric Association’s Guideline for Major Depressive Disorder: A Commentary

The American Psychiatric Association (APA) published a new guideline for Major Depressive Disorder (MDD) which will undoubtedly be used by many practitioners to guide clinical decision-making. In fact, it is non-psychiatrist clinicians who prescribe the majority of antidepressants (AD). We review the APA’s most recent guideline on MDD and report on our observations