Further on the current algebra of WZNW models at and away from criticality

We comment on the off-critical perturbations of WZNW models by a mass term as well as by another descendent operator, when we can compare the results with further algebra obtained from the Dirac quantization of the model, in such a way that a more general class of models be included. We discover, in both cases, hidden Kac-Moody algebras obeyed by some currents in the off-critical case, which in several cases are enough to completely fix the correlation functions.

The Myth of the Rational Market: Nudging Each Other Away from Fool’s Gold

A flurry of media commentary and several new books are focused on the recent financial crisis and near economic collapse. A Newsweek article by Zakaria (2009), “Greed is Good (To a Point),” suggests reconsidering the role of greed in capitalism. This is also the theme in Fools Gold (Tett, 2009), a story about the way derivatives markets have evolved: showing greed at its worst. In many ways this is the core source of the current set of problems. In some sense, these perspectives are integrated in The Myth of the Rational Market by Fox (2009), who traces the thinking on the efficient market hypothesis, now understood for what it is: a myth. Both books are based in large part on interviews with major players in the crisis. There are also books drawing mainly on science, but still quite accessible to general readers, as represented in Nudge by Thaler and Sunstein (2008). Both have done extensive research on human foibles in economic choice. There is also Animal Spirits (Akerlof and Schiller, 2009), a book about what Keynesian economics is really about, a look at human forces at work. Akerlof is a Nobel prize winner in economics, who before this has pointed to the problems with presuming rationality in real markets. Schiller is one of the few economists who predicted these events.

Community Responsibility for Runaway and Thrownaway Youth--Commentary

The following is a commentary on an article discussing homeless youth and the need for communities to address this issue. It is clear that research is needed to understand more about the extent, causes and consequences of youth homelessness whether the youth has run or been thrown away from home. Drawing on interviews conducted with homeless and runaway youth, this commentary calls for community responsibility directed at locating these youth, acknowledging their presence in communities across the U.S., and developing coordinated multijurisdictional responses that support youth development and build on the strengths that have helped them survive.

Learning about Self Far From Home: A Pre-service Teacher’s Intercultural Development During an International Program

Preparing teachers to effectively teach culturally diverse students, teacher educators advocate for the use of cross-cultural field experiences, including international study abroad programs. This paper reports on a qualitative case study of two pre-service teachers’ intercultural development during a semester-long teacher education study abroad program in London, England. Findings indicate that international experiences provide a catalyst to move pre-service teachers forward in their intercultural development. Implications include the need for multicultural teacher educators to take a developmental approach to pre-service teacher education informed by theories of intercultural development and cultural learning developed within intercultural communications.

Running away from side effects: physical exercise as a complementary intervention for breast cancer patients

The number of breast cancer survivors increases every year, thanks to the development of new treatments and screening techniques. However, patients present with numerous side effects that may affect their quality of life. Exercise has been demostrated to reduce some of these side effects, but in spite of this, few breast cancer patientes know and follow the exercise recommendations needed to remain healthy. In this review, we describe the differente breast cancer treatments and the related side effects and implications of exercise in relation to these. We propose that exercise could be and integrative complementary intervention to improve physiological, physical and psychological factors that affect survival and quality of life of these patients. For that reason, the main objective of this review is to provide a general overview of exercise benefits in breast cancer patients and recommendations of how to design exercise interventions in patients with different side effects.

Tight frames of k-plane ridgelets and the problem of representing objects that are smooth away from d-dimensional singularities in Rn

For each pair (n, k) with 1 ≤ k < n, we construct a tight frame (ρλ : λ ∈ Λ) for L2 (Rn), which we call a frame of k-plane ridgelets. The intent is to efficiently represent functions that are smooth away from singularities along k-planes in Rn. We also develop tools to help decide whether k-plane ridgelets provide the desired efficient representation. We first construct a wavelet-like tight frame on the X-ray bundle χn,k—the fiber bundle having the Grassman manifold Gn,k of k-planes in Rn for base space, and for fibers the orthocomplements of those planes. This wavelet-like tight frame is the pushout to χn,k, via the smooth local coordinates of Gn,k, of an orthonormal basis of tensor Meyer wavelets on Euclidean space Rk(n−k) × Rn−k. We then use the X-ray isometry [Solmon, D. C. (1976) J. Math. Anal. Appl. 56, 61–83] to map this tight frame isometrically to a tight frame for L2(Rn)—the k-plane ridgelets. This construction makes analysis of a function f ∈ L2(Rn) by k-plane ridgelets identical to the analysis of the k-plane X-ray transform of f by an appropriate wavelet-like system for χn,k. As wavelets are typically effective at representing point singularities, it may be expected that these new systems will be effective at representing objects whose k-plane X-ray transform has a point singularity. Objects with discontinuities across hyperplanes are of this form, for k = n − 1.

Phototaxis away from blue light by an Escherichia coli mutant accumulating protoporphyrin IX.

The hemH gene of Escherichia coli encodes ferrochelatase (EC 4.99.1.1), the enzyme that catalyzes the last step in the production of heme, namely the synthesis of heme from protoporphyrin IX plus Fe2+. The behavioral responses to light were studied in E. coli carrying a hemH mutation. It was shown that the hemH mutant displayed a tumbling response upon illumination and a running response upon removal of the light. The most effect light to induce a tumbling response in the hemH mutant was blue light (396-450 nm). The chemotaxis machinery was needed for the light-induced tumbling response in the hemH mutant. The bacterial defect is an analog of the human inherited disease erythropoietic protoporphyria.