Advances in imaging for atrial fibrillation ablation.

Over the last fifteen years, our understanding of the pathophysiology of atrial fibrillation (AF) has paved the way for ablation to be utilized as an effective treatment option. With the aim of gaining more detailed anatomical representation, advances have been made using various imaging modalities, both before and during the ablation procedure, in planning and execution. Options have flourished from procedural fluoroscopy, electroanatomic mapping systems, preprocedural computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and combinations of these technologies. Exciting work is underway in an effort to allow the electrophysiologist to assess scar formation in real time. One advantage would be to lessen the learning curve for what are very complex procedures. The hope of these developments is to improve the likelihood of a successful ablation procedure and to allow more patients access to this treatment

SOTA 2004 Managing for Value(s) in a Commoditized World

Since its inception in 1995, Human Resource Planning Society’s State of the Art/Practice study has become an important way that the Society seeks to generate and disseminate information critical to effective HR strategy decision making. The study began as an effort to identify the major issues driving organizations and causing transformations in HR (Caimano, Canavan, & Hill, 1998; Ulrich & Eichinger, 1995; 1996; Wright, Dyer, & Takla, 1998). More recently, the SOTA/P has focused on drilling down more deeply to understand HR’s role in critical strategic issues such as e-business (Wright and Dyer, 1999) and using HR to build a customer-focused company (Overholt and Grannell, 2002). The 2004 SOTA/P returns to the original roots, and seeks to describe the competitive landscape, and the implications of these trends for HR

Solar and geothermal energy for low-carbon space heating and energy independence.

In developed countries, space heating is highly dependent on fossil fuels consumption. Also, the non-renewable fuels combustion emits CO2 which is claimed to impact the most on greenhouse effect. The utilization of Renewable Energy Sources (RES) for space heating, instead of fossil fuels, has been found to be feasible for systems’ greater energy independence and reduction in CO2 emissions. Solar Assisted Ground Source Heat Pump (SAGSHP) systems are a promising technology which can be used to accomplish the above framed target. A mathematic model of a SAGSHP system was built and a parametric analysis for Birmingham which is a city located in the UK’s West Midlands was conducted. Two scenarios based on two different dwellings were investigated, the one was a house recently erected and the other was a refurbished house. As regards the new house, simulation results showed that the utilized energy for space heating and Domestic Hot Water (DHW) can vary from 33% up to 73% RES dependent and, at the same time, electricity generation can be 2.21 times higher than the system’s demand. As regards the energy renovated dwelling, the RES contribution to the delivered heat was found to be between the 33% and 63%, while the electricity generation did not result in any surplus energy from the consumed. Finally, by making use of SAGSHP system instead of a natural Gas boiler, the reduction of CO2 emissions was found to be between 300kg/year and 2,170kg/year for the new building and from 245kg/year up to 3,221kg/year for the refurbished house, respectively. In both cases, SAGSHP systems proved to be a feasible practice for greater energy independence from non-renewable energy sources with substantial positive impact on the greenhouse gasses emissions

Partner or Guardian? HR’s Challenge in Balancing Value and Values

[Excerpt] Is HR at a crossroad? A number of signs seem to be pointing that way. Increasingly HR executives are faced with a critical decision: Will they continue on their journey to be business leaders, , with full sway and equal influence in organizational decision making, or will they take the short-cut by sacrificing professional ethics and values for a seat at the table. This challenge is exemplified by the story of Delta Airlines

Toward a Unifying Framework for Exploring Fit and Flexibility in Strategic Human Resource Management

This paper presents a framework for studying the concepts of fit and flexibility in the field of Strategic Human Resource Management (Strategic HRM) focusing on HRM practices, employee skills, and employee behaviors and reviews past conceptual and empirical work within that framework. A model of Strategic HRM is presented and this model is used to explore the concepts of fit and flexibility as they apply to Strategic HRM. The concepts of resource and coordination flexibility are applied to Strategic HRM, and the implications of the framework for both the practice of and research on Strategic HRM are discussed

Convergence of the restricted Nelder-Mead algorithm in two dimensions

The Nelder-Mead algorithm, a longstanding direct search method for unconstrained optimization published in 1965, is designed to minimize a scalar-valued function f of n real variables using only function values, without any derivative information. Each Nelder-Mead iteration is associated with a nondegenerate simplex defined by n+1 vertices and their function values; a typical iteration produces a new simplex by replacing the worst vertex by a new point. Despite the method's widespread use, theoretical results have been limited: for strictly convex objective functions of one variable with bounded level sets, the algorithm always converges to the minimizer; for such functions of two variables, the diameter of the simplex converges to zero, but examples constructed by McKinnon show that the algorithm may converge to a nonminimizing point. This paper considers the restricted Nelder-Mead algorithm, a variant that does not allow expansion steps. In two dimensions we show that, for any nondegenerate starting simplex and any twice-continuously differentiable function with positive definite Hessian and bounded level sets, the algorithm always converges to the minimizer. The proof is based on treating the method as a discrete dynamical system, and relies on several techniques that are non-standard in convergence proofs for unconstrained optimization.Comment: 27 page

Circulating Subbeam Systems and the Physics of Pulsar Emission

The purpose of this paper is to suggest how detailed single-pulse observations of ``slow'' radio pulsars may be utilized to construct an empirical model for their emission. It links the observational synthesis developed in a series of papers by Rankin starting in the 1980s to the more recent empirical feedback model of Wright (2003a) by regarding the entire pulsar magnetosphere as a non-steady, non-linear interactive system with a natural built-in delay. It is argued that the enhanced role of the outer gap in such a system indicates an evolutionary link to younger pulsars, in which this region is thought to be highly active, and that pulsar magnetospheres should no longer be seen as being ``driven'' by events on the neutron star's polar cap, but as having more in common with planetary magnetospheres and auroral phenomena.Comment: 15 pages, 3 figure

Human Resources Strategy: The Era of Our Ways

The purpose of this chapter is to discuss some of the main features and trends in human resources (HR) strategy. Inasmuch as people are among the most important resources available to firms, one could argue that HR strategy should be central to any debate about how firms achieve competitive advantage. But this “people are our most important asset” argument is actually fairly hollow in light of the evidence. Far too many articles on HR start with this premise, but the reality is that organizations have historically not rested their fortunes on human resources. The HR function remains among the least influential in most organizations, and competitive strategies have not typically been based on the skills, capabilities, and behaviors of employees. In fact, as Snell, Youndt and Wright (1996:62) noted, in the past executives have typically tried to “take human resources out of the strategy equation--i.e., by substituting capital for labor where possible, and by designing hierarchical organizations that separate those who think from those who actually do the work.

The HR-Firm Performance Relationship: Can it be in the Mind of the Beholder?

This study examined whether respondents’ implicit theories of performance could impact their responses to surveys regarding HR practices and effectiveness. Senior Human Resource and Line Executives and MBA, graduate Engineering, and graduate HR students read scenarios of high and low performing firms and were asked to report on the prevalence of various HR practices and effectiveness of the HR function in each firm. Results indicated that all four groups of respondents held implicit theories that high performing firms were characterized by extensive HR practices and had highly effective HR functions relative to low performing firms. Subjects with substantial work experience reported greater differences between and high and low performing firms than did subjects with relatively little work experience. The implications of these results for research on the HR Practices – Firm Performance relationship are discussed

Structural, vibrational and thermal properties of densified silicates : insights from Molecular Dynamics

Structural, vibrational and thermal properties of densified sodium silicate (NS2) are investigated with classical molecular dynamics simulations of the glass and the liquid state. A systematic investigation of the glass structure with respect to density was performed. We observe a repolymerization of the network manifested by a transition from a tetrahedral to an octahedral silicon environment, the decrease of the amount of non-bridging oxygen atoms and the appearance of three-fold coordinated oxygen atoms (triclusters). Anomalous changes in the medium range order are observed, the first sharp diffraction peak showing a minimum of its full-width at half maximum according to density. The previously reported vibrational trends in densified glasses are observed, such as the shift of the Boson peak intensity to higher frequencies and the decrease of its intensity. Finally, we show that the thermal behavior of the liquid can be reproduced by the Birch-Murnaghan equation of states, thus allowing us to compute the isothermal compressibility