Misleading Betas: An Educational Example

The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical “Anscombe quartet” results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the dual-beta model. Using data from 39 mutual funds, it is shown how very different dual-beta models can lead to the same CAPM beta estimates, much like the Anscombe quartet scenarios

Employee Relations Ethics and the Changing Nature of the American Workforce

Much is being written today about the changing nature of the American workforce. This article summarizes 10 of these changes: (a) global competition; (b) the changing skills of work; (c) the declining impact of unions; (d) the altered human composition of the workforce; (e) the effects of continuous improvement, downsizing, and reengineering; (f) the growing use of part-time employees; (g) the widening income gap; (h) lessened employer and employee loyalty and commitment; (i) early retirement programs; and (j) telecommunications and virtual employees. Rather than just identifying and documenting these trends, this article discusses the ethical implications of such movements. In this article, employee relations ethics is defined as treating employees properly, with respect and dignity. The term employee relations ethics is used both individually and collectively to analyze the negative human results from a moral rather than an economic perspective. The age-old clash between bottom-line mentality (economics) versus higher order thinking (ethics) is revisited with a focus on employees, not owners (old theory) or customers (new theory)

Unidirectional Transition Waves in Bistable Lattices

We present a model system for strongly nonlinear transition waves generated in a periodic lattice of bistable members connected by magnetic links. The asymmetry of the on-site energy wells created by the bistable members produces a mechanical diode that supports only unidirectional transition wave propagation with constant wave velocity. We theoretically justify the cause of the unidirectionality of the transition wave and confirm these predictions by experiments and simulations. We further identify how the wave velocity and profile are uniquely linked to the double-well energy landscape, which serves as a blueprint for transition wave control

Singular optics and topological photonics

For centuries, singularities in wave fields have been a mainstay of interest in multiple areas of physics, ranging from plasma physics, fluid dynamics and atmospheric physics to optics and photonics [1]. In optics, energy and momentum flow around singularities in the interference field can twist to form vortices, which carry angular momentum [2–4]. Singular Optics is the branch of physics that encompasses studies of structured light with localized and extended singularities, such as optical vortices in scalar optical fields and polarization singularities in vector fields [2, 5, 6]. It has been pioneered by the publication of a seminal paper of Nye and Berry 'Dislocations in wave trains' in 1974 [7], and has recently celebrated its 40th anniversary

Unidirectional Transition Waves in Bistable Lattices

We present a model system for strongly nonlinear transition waves generated in a periodic lattice of bistable members connected by magnetic links. The asymmetry of the on-site energy wells created by the bistable members produces a mechanical diode that supports only unidirectional transition wave propagation with constant wave velocity. We theoretically justify the cause of the unidirectionality of the transition wave and confirm these predictions by experiments and simulations. We further identify how the wave velocity and profile are uniquely linked to the double-well energy landscape, which serves as a blueprint for transition wave control

Efficacy and tolerability of vardenafil in Asian men with erectile dysfunction

10.1111/j.1745-7262.2008.00388.xAsian Journal of Andrology103495-50