Elicitation of ambiguous beliefs with mixing bets

I consider the elicitation of ambiguous beliefs about an event and show how to identify the interval of relevant probabilities (representing ambiguity perception) for several classes of ambiguity averse preferences. The agent reveals her preference for mixing binarized bets on the uncertain event and its complement under varying betting odds. Under ambiguity aversion, mixing is informative about the interval of beliefs. In particular, the mechanism allows to distinguish ambiguous beliefs from point beliefs, and identifies the belief interval for maxmin preferences. For ambiguity averse smooth second order and variational preferences, the mechanism reveals inner bounds for the belief interval, which are sharp under additional assumptions. In an experimental study, participants perceive almost as much ambiguity for natural events (generated by the stock exchange and by a prisoners dilemma game) as for the Ellsberg Urn, indicating that ambiguity may play a role in real-world decision making

Quantum thermodynamics of the resonant-level model with driven system-bath coupling

We study nonequilibrium thermodynamics in a fermionic resonant level model with arbitrary coupling strength to a fermionic bath, taking the wide-band limit. In contrast to previous theories, we consider a system where both the level energy and the coupling strength depend explicitly on time. We find that, even in this generalized model, consistent thermodynamic laws can be obtained, up to the second order in the drive speed, by splitting the coupling energy symmetrically between system and bath. We define observables for the system energy, work, heat, and entropy, and calculate them using nonequilibrium Green's functions. We find that the observables fulfill the laws of thermodynamics, and connect smoothly to the known equilibrium results.Comment: 9 pages, 5 figure

Simple vertex correction improves GW band energies of bulk and two-dimensional crystals

The GW self-energy method has long been recognized as the gold standard for quasiparticle (QP) calculations of solids in spite of the fact that the neglect of vertex corrections and the use of a DFT starting point lacks rigorous justification. In this work we remedy this situation by including a simple vertex correction that is consistent with an LDA starting point. We analyse the effect of the self-energy by splitting it into a short-range and long-range term which are shown to govern respectively the center and size of the band gap. The vertex mainly improves the short-range correlations and therefore has a small effect on the band gap, while it shifts the band gap center up in energy by around 0.5 eV in good agreement with experiments. Our analysis also explains how the relative importance of short- and long-range interactions in structures of different dimensionality is reflected in their QP energies. Inclusion of the vertex comes at practically no extra computational cost and even improves the basis set convergence compared to GW. The method thus provides an efficient and rigorous improvement over the GW approximation and sets a new standard for quasiparticle calculations of solids

Block-Coordinate Frank-Wolfe Optimization for Structural SVMs

We propose a randomized block-coordinate variant of the classic Frank-Wolfe algorithm for convex optimization with block-separable constraints. Despite its lower iteration cost, we show that it achieves a similar convergence rate in duality gap as the full Frank-Wolfe algorithm. We also show that, when applied to the dual structural support vector machine (SVM) objective, this yields an online algorithm that has the same low iteration complexity as primal stochastic subgradient methods. However, unlike stochastic subgradient methods, the block-coordinate Frank-Wolfe algorithm allows us to compute the optimal step-size and yields a computable duality gap guarantee. Our experiments indicate that this simple algorithm outperforms competing structural SVM solvers.Comment: Appears in Proceedings of the 30th International Conference on Machine Learning (ICML 2013). 9 pages main text + 22 pages appendix. Changes from v3 to v4: 1) Re-organized appendix; improved & clarified duality gap proofs; re-drew all plots; 2) Changed convention for Cf definition; 3) Added weighted averaging experiments + convergence results; 4) Clarified main text and relationship with appendi

Ch. 11 - Becoming a Story: Searching for Music Educations

This short philosophical chapter borrows and diverges from Estelle Jorgensen’s In Search of Music Education. It aims to address the pertinent and defiant questions asked over two decades ago, while re-position them in light of current challenges. Following Jorgensen’s style—carefully and tactically—this chapter draws a line of flight between philosophical and policy-oriented ways of thinking, underlining some ways in which the two meet and how pertinent these encounters can be to music educators today. The chapter makes use and highlights the potential of craftly constructed epistemological familiarity and how it can engender practice. Specifically, it reminds and exemplifies to the reader how a ‘wondering disposition’ about one’s work and field, remain central to any critical practice. Specially so, in times where democratic challenges strongly challenge our social and educational environments

T-Zellen mit rekombinanten Immunrezeptoren lysieren autologe Tumorzellen und eliminieren Tumore durch gezielte Eradikation von Tumorstammzellen

Die adoptive Immuntherapie maligner Tumore beruht darauf, T-Zellen durch retrovirale Expression eines rekombinanten Rezeptors (Immunrezeptor) Spezifität für ein Tumor-assoziiertes Antigen (TAA) zu verleihen und diese modifizierten T-Zellen zu aktivieren. Das Konzept basiert auf der Annahme, dass T-Zellen von Tumorpatienten spezifisch aktiviert werden können, obwohl ein progredienter Verlauf der Krankheit mit zunehmender Anergie der T-Lymphozyten assoziiert ist. Die Umsetzbarkeit der Hypothese wurde im Rahmen dieser Arbeit anhand der chronisch lymphatischen Leukämie (CLL), einer bislang nicht heilbaren Form der hämatologischen Neoplasie mit hohen Rezidivraten, untersucht. Unsere Ergebnisse zeigen, dass die Anergie zytolytischer T-Zellen aus CLL-Patienten durch die Expression eines Immunrezeptors, der gegen CD19 auf CLL Zellen gerichtet ist, überwunden werden kann und diese T-Zellen durch ein CD3zeta Signal aktiviert werden können. Die Zytolyse wird, unabhängig von Fas oder TNF-alpha, durch Granzym/Perforin ausgelöst. Die spezifische T-Zell Aktivierung, aber nicht die zytolytische Kapazität, wird durch einen kombinierten CD28-CD3zeta kostimulatorischen Immunrezeptor erhöht. Die erhaltenen Resultate zeigen, dass naive T-Zellen sogar aus Patienten in fortgeschrittenen Stadien der Krankheit zu einer effizienten "Graft-versus-Leukemia" Reaktion modifiziert werden können. Diese und nahezu alle anderen Strategien der Tumortherapie beruhen auf der Annahme, dass alle Tumorzellen dieselben malignen Eigenschaften besitzen. Im Gegensatz dazu postuliert die Tumorstammzellhypothese, dass das Tumorwachstum von einer kleinen Population pluripotenter Zellen gesteuert wird. Diese Tumorstammzellen besitzen die Fähigkeit der Selbsterneuerung, der Differenzierung durch asymmetrische Teilung und der Möglichkeit zu metastasieren. Am Modell des malignen Melanoms wurde in dieser Arbeit eine kleine Subpopulation von Zellen identifiziert, die die Eigenschaften einer Tumorstammzellfraktion aufweist. Die selektive Eliminierung dieser Zellen durch modifizierte T-Lymphozyten führte in vivo zu einer Eradikation des induzierten Tumors, obwohl die Population der Zellen nur 0,1% der gesamten Melanomzellen beinhaltet. Nach der Zerstörung der Tumorstammzellen wird in der Masse der Tumorzellen die Apoptose durch noch nicht näher definierte Mechanismen ausgelöst. Unsere Daten liefern einen Hinweis für die Anwendbarkeit der adoptiven Immuntherapie gegen Tumorstammzellen und regen dazu an, bisherige Behandlungsschemata zu überdenken