The merger of vertically offset quasi-geostrophic vortices

We examine the critical merging distance between two equal-volume, equal-potential-vorticity quasi-geostrophic vortices. We focus on how this distance depends on the vertical offset between the two vortices, each having a unit mean height-to-width aspect ratio. The vertical direction is special in the quasi-geostrophic model (used to capture the leading-order dynamical features of stably stratified and rapidly rotating geophysical flows) since vertical advection is absent. Nevertheless vortex merger may still occur by horizontal advection. In this paper, we first investigate the equilibrium states for the two vortices as a function of their vertical and horizontal separation. We examine their basic properties together with their linear stability. These findings are next compared to numerical simulations of the nonlinear evolution of two spheres of potential vorticity. Three different regimes of interaction are identified, depending on the vertical offset. For a small offset, the interaction differs little from the case when the two vortices are horizontally aligned. On the other hand, when the vertical offset is comparable to the mean vortex radius, strong interaction occurs for greater horizontal gaps than in the horizontally aligned case, and therefore at significantly greater full separation distances. This perhaps surprising result is consistent with the linear stability analysis and appears to be a consequence of the anisotropy of the quasi-geostrophic equations. Finally, for large vertical offsets, vortex merger results in the formation of a metastable tilted dumbbell vortex.Publisher PDFPeer reviewe

Is poetry therapy an appropriate intervention for clients recovering from anorexia? A critical review of the literature and client report

© 2017 Informa UK Limited, trading as Taylor & Francis Group. Poetry therapy is an arts-based psychotherapeutic intervention, often delivered in groups. This paper argues that the process and benefits of poetry therapy may be particularly suited to clients recovering from anorexia, as an adjunct to other treatments. Poetry therapy and its history are described briefly, and the relevance of poetry therapy for clients recovering from anorexia is outlined. After one client contributes her experience of this treatment for illustration, the paper offers a review of the evidence base for poetry therapy for eating disorders, and argues that, while research is limited, further research is warranted. Finally, a description of one form of clinical application is offered, to enable replication

High-Density Electromyography Provides New Insights into the Flexion Relaxation Phenomenon in Individuals with Low Back Pain.

Recent research using high-density electromyography (HDEMG) has provided a more precise understanding of the behaviour of the paraspinal muscles in people with low back pain (LBP); but so far, HDEMG has not been used to investigate the flexion relaxation phenomenon (FRP). To evaluate this, HDEMG signals were detected with grids of electrodes (13 × 5) placed bilaterally over the lumbar paraspinal muscles in individuals with and without LBP as they performed repetitions of full trunk flexion. The root mean square of the HDEMG signals was computed to generate the average normalized amplitude; and the spatial FRP onset was determined and expressed as percentage of trunk flexion. Smoothing spline analysis of variance models and the contrast cycle difference approach using the Bayesian interpretation were used to determine statistical inference. All pain-free controls and 64.3% of the individuals with LBP exhibited the FRP. Individuals with LBP and the FRP exhibited a delay of its onset compared to pain-free controls (significant mean difference of 13.3% of trunk flexion).  They also showed reduced normalized amplitude compared to those without the FRP, but still greater than pain-free controls (significant mean difference of 27.4% and 11.6% respectively). This study provides novel insights into changes in lumbar muscle behavior in individuals with LBP

Skepticism about Corporate Punishment Revisited

Some societies used to impose liability on inanimate objects, a practice we’d now regard as silly and confused. When we punish corporations today, are we making similar mistakes? Here I consider some important sources of philosophical skepticism about imposing criminal liability on corporations, and I argue that they admit of answers, which places punishing corporations on stronger footing than punishing inanimate objects. First, I consider the eligibility challenge, which asserts that corporations are not the right kind of thing to be punished. Second, the reductionist challenge insists that corporate culpability always reduces to individual culpability. I suggest that progress can be made in addressing these challenges by asking the right law-focused questions and attending to recent developments in criminal law theory and moral philosophy

Plea Bargaining: The Influence of Counsel

For the criminal defendant, his attorney acts as his loyal and zealous advocate before the court (American Bar Association, 2015), and due process protections of the U.S. adversarial system have afforded this relationship special privilege. In this chapter, we explore the influence and role of the attorney in plea decision making. We first explore the legal context of the attorney’s role in plea bargaining, reviewing several cases that address a defendant’s right to effective assistance of counsel. We then review the shadow of trial theory and other theoretical perspectives as they relate to the attorney’s role in the plea-bargaining process, providing a theoretical background to understand how the attorney’s advice and role likely influence a defendant’s decision to accept a guilty plea offer. Then, we discuss the research examining legal and extra-legal factors that influence the type of advice an attorney gives a client contemplating a guilty plea offer, considering the implications of this research for the current standards used to define effective assistance of counsel. Last, we explore future research possibilities that could contribute to the understanding of the role the attorney plays in the plea-bargaining process