On the c-theorem in more than two dimensions

Several pieces of evidence have been recently brought up in favour of the c-theorem in four and higher dimensions, but a solid proof is still lacking. We present two basic results which could be useful for this search: i) the values of the putative c-number for free field theories in any even dimension, which illustrate some properties of this number; ii) the general form of three-point function of the stress tensor in four dimensions, which shows some physical consequences of the c-number and of the other trace-anomaly numbers.Comment: Latex, 7 pages, 1 tabl

Short distance behaviour of correlators in the 2D Ising model in a magnetic field

We study the spin-spin, spin-energy and energy-energy correlators in the 2d Ising model perturbed by a magnetic field. We compare the results of a set of high precision Montecarlo simulations with the predictions of two different approximations: the Form Factor approach, based on the exact S-matrix description of the model, and a short distance perturbative expansion around the conformal point. Both methods give very good results, the first one performs better for distances larger than the correlation length, while the second one is more precise for distances smaller than the correlation length. In order to improve this agreement we extend the perturbative analysis to the second order in the derivatives of the OPE constants.Comment: 46 pages, 10 figures, final version to appear in Nucl. Phys.

Theory of mind in the social sciences: an experiment on strategic thinking in children

This study investigates mentalizing and strategic thinking in children in elementary school age (from 7 to 12 years old). Drawing from previous literature in behavioral and experiments economics and cognitive science, we conduct experiments in which children of different ages make choices in a series of one-shot, simultaneous move two-person games in normal form. We test the ability of our subjects to reason strategically and compare their behavioral patterns with those of adult players engaged in similar tasks (Di Guida and Devetag 2012). Our results show that even younger children are capable of perspective taking: they seem to grasp the essence of strategic thinking, to recognize similarities across games, and behave consistently. In addition, children are sensitive to the attractive power of focal points (Di Guida and Devetag 2012), which are perceived as natural coordination devices even when they are not part of the game equilibria, in line with previous results. Children are also able to perceive the risk-return tradeoffs implied in strategic decisions, as shown by their preference for \u201csafe\u201d strategies (i.e., strategies yielding an acceptable payoff for any choice of the opponent). Finally, only a minority behaves according to na\uefve heuristics such as opting for the strategy giving the maximum payoff. Our findings contribute to the interdisciplinary literature on the origin of fairness-based norms within societies and on the cognitive and social determinants of strategic interaction

Non Perturbative Renormalization Group, momentum dependence of nn-point functions and the transition temperature of the weakly interacting Bose gas

We propose a new approximation scheme to solve the Non Perturbative Renormalization Group equations and obtain the full momentum dependence of $n$-point functions. This scheme involves an iteration procedure built on an extension of the Local Potential Approximation commonly used within the Non Perturbative Renormalization Group. Perturbative and scaling regimes are accurately reproduced. The method is applied to the calculation of the shift $\Delta T_c$ in the transition temperature of the weakly repulsive Bose gas, a quantity which is very sensitive to all momenta intermediate between these two regions. The leading order result is in agreement with lattice calculations, albeit with a theoretical uncertainty of about 25%. The next-to-leading order differs by about 10% from the best accepted result

Structure, regulation, and function of protein tyrosine phosphatases

The phosphorylation of tyrosyl residues in proteins is an essential aspect of many signal transduction events, including the control of both normal and neoplastic cell growth and proliferation. Since the earliest observations of tyrosine phosphorylation, it has been appreciated that this is a reversible process in which the net level of phosphate in a target substrate reflects the balance between the competing action of kinases and phosphatases. Thus, in cells transformed by temperature-sensitive mutants of Rous sarcoma virus, an elevation in the levels of phosphotyrosine is observed at the permissive temperature, at which the kinase is active; however, if the cells are shifted to the nonpermissive temperature, at which the kinase is inactivated, a rapid dephosphorylation of tyrosyl residues ensues due to the action of protein tyrosine phosphatases (PTPases) (Sefton et al. 1980). The last 10 years has witnessed great progress in the characterization of the protein tyrosine kinases, whereas..

Local treatment with electrochemotherapy of superficial angiosarcomas: Efficacy and safety results from a multi-institutional retrospective study

Background: Angiosarcoma is an aggressive vascular neoplasm with a high propensity for local recurrence. Electrochemotherapy is an emerging skin-directed therapy, exerting prominent cytotoxic activity, and antivascular effects. Its efficacy in angiosarcoma has not been investigated. Methods: This multicenter retrospective analysis reviewed patients who underwent electrochemotherapy from 2007 to 2014 for superficial advanced angiosarcomas. Bleomycin was administered intravenously and delivered within tumors by means of percutaneously applied electric pulses, according to the European Standard Operating Procedures for Electrochemotherapy. Tumor assessment was performed using RECIST (version 1.1). Toxicity (CTCAE, v4.0) and local progression-free survival (LPFS) were also evaluated. Results: Nineteen patients (13 with locally advanced and 6 with metastatic angiosarcomas) were treated. Tumor sites were: scalp (n¼5), breast(n¼8), other skin sites (n¼3), and soft tissue (n¼3). Target lesions (n¼54) ranged in size from 1.5 to 2.5 cm (median, 2 cm). Treatment was well tolerated. After 2 months, an objective response was observed in 12/19 (63%) patients, complete in 8 (42%). One-year LPFS within treatment field was 68%. Local symptom improvement included palliation of bleeding (5/19 patients) and pain relief (6/19 patients). Conclusions: Electrochemotherapy may represent a new locoregional treatment for selected patients with superficial angiosarcomas

A new class of short distance universal amplitude ratios

We propose a new class of universal amplitude ratios which involve the first terms of the short distance expansion of the correlators of a statistical model in the vicinity of a critical point. We will describe the critical system with a conformal field theory (UV fixed point) perturbed by an appropriate relevant operator. In two dimensions the exact knowledge of the UV fixed point allows for accurate predictions of the ratios and in many nontrivial integrable perturbations they can even be evaluated exactly. In three dimensional O(N) scalar systems feasible extensions of some existing results should allow to obtain perturbative expansions for the ratios. By construction these universal ratios are a perfect tool to explore the short distance properties of the underlying quantum field theory even in regimes where the correlation length and one point functions are not accessible in experiments or simulations.Comment: 8 pages, revised version, references adde

Theory of mind in the social sciences: an experiment on strategic thinking in children

This study investigates mentalizing and strategic thinking in children in elementary school age (from 7 to 12 years old). Drawing from previous literature in behavioral and experiments economics and cognitive science, we conduct experiments in which children of different ages make choices in a series of one-shot, simultaneous move two-person games in normal form. We test the ability of our subjects to reason strategically and compare their behavioral patterns with those of adult players engaged in similar tasks (Di Guida and Devetag 2012). Our results show that even younger children are capable of perspective taking: they seem to grasp the essence of strategic thinking, to recognize similarities across games, and behave consistently. In addition, children are sensitive to the attractive power of focal points (Di Guida and Devetag 2012), which are perceived as natural coordination devices even when they are not part of the game equilibria, in line with previous results. Children are also able to perceive the risk-return tradeoffs implied in strategic decisions, as shown by their preference for “safe” strategies (i.e., strategies yielding an acceptable payoff for any choice of the opponent). Finally, only a minority behaves according to naïve heuristics such as opting for the strategy giving the maximum payoff. Our findings contribute to the interdisciplinary literature on the origin of fairness-based norms within societies and on the cognitive and social determinants of strategic interaction

New Algorithm of the Finite Lattice Method for the High-temperature Expansion of the Ising Model in Three Dimensions

We propose a new algorithm of the finite lattice method to generate the high-temperature series for the Ising model in three dimensions. It enables us to extend the series for the free energy of the simple cubic lattice from the previous series of 26th order to 46th order in the inverse temperature. The obtained series give the estimate of the critical exponent for the specific heat in high precision.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Letter