Long-term planning versus short-term planning in the asymptotical location problem

Given the probability measure $\nu$ over the given region $\Omega\subset \R^n$, we consider the optimal location of a set $\Sigma$ composed by $n$ points \Om in order to minimize the average distance \Sigma\mapsto \int_\Om \dist(x,\Sigma) d\nu (the classical optimal facility location problem). The paper compares two strategies to find optimal configurations: the long-term one which consists in placing all $n$ points at once in an optimal position, and the short-term one which consists in placing the points one by one adding at each step at most one point and preserving the configuration built at previous steps. We show that the respective optimization problems exhibit qualitatively different asymptotic behavior as $n\to\infty$, although the optimization costs in both cases have the same asymptotic orders of vanishing.Comment: for more pictures and some movies as well, see http://www.sissa.it/~brancoli

Two-point functions for N=4 Konishi-like operators

We compute the two-point function of Konishi-like operators up to one-loop order, in N=4 supersymmetric Yang-Mills theory. We work perturbatively in N=1 superspace. We find the expression expected on the basis of superconformal invariance and determine the normalization of the correlator and the anomalous dimension of the operators to order g^2 in the coupling constant.Comment: 10 pages, 3 figures; added references and some clarifying comment

Conformal boundary and geodesics for AdS5×S5AdS_5\times S^5 and the plane wave: Their approach in the Penrose limit

Projecting on a suitable subset of coordinates, a picture is constructed in which the conformal boundary of $AdS_5\times S^5$ and that of the plane wave resulting in the Penrose limit are located at the same line. In a second line of arguments all $AdS_5\times S^5$ and plane wave geodesics are constructed in their integrated form. Performing the Penrose limit, the approach of null geodesics reaching the conformal boundary of $AdS_5\times S^5$ to that of the plane wave is studied in detail. At each point these null geodesics of $AdS_5\times S^5$ form a cone which degenerates in the limit.Comment: some statements refined, chapter 5 rewritten to make it more precise, some typos correcte

Adaptation of the Penetration-Aspiration Scale to Open Partial Horizontal Laryngectomy: reliability analysis

The study aimed at adapting the Penetration-Aspiration scale to OPHL and analysing its reliability

A valid academic path to promote respiratory physiotherapy

A one- year post- graduate Master in Physiotherapy and Pulmonary Rehabilitation has been offered within the University of Milan Medical School in collaboration with Associaz ione Italiana Riabilitatori dell\u2019Insufficienz a Respiratoria (ARIR). The aim is to cover a gap in Italian Physiotherapy academic curricula offering a course with theoretical and practical teaching that make students capable of using different techniques and procedures in respiratory physiotherapy. After the recognition by the International Education Recognition System (IERS), ARIR wanted to investigate if and how this course has affected students'attitude and their profession. METHODS A structured questionnaire made up of 15 multiple- choices items (8 on perceived quality of education and 7 on professional change) was sent by email to all physiotherapists who graduated in the previous four editions of the Master. One month was given for completion. Age, gender, year of degree and year of Master where considered as background variables. RESULTS We had a 78% response rate with 57 out of 73 physiotherapists sending the questionnaire back. Mean age was 37 years (23- 60) and women were the majority (78%). Forty- two students (74%) worked in the respiratory field at the time of application but only 15 (36%) dealt with respiratory patients only. Expectations were completely met at the end of Master for 71% of physiotherapists. 96% reported greater professional and clinical skills after the master with a 67% saying working team relationship has improved. 28% improved their job position thanks to the master degree and physiotherapy working in the respiratory field increased by 22%. CONCLUSIONS This course seems to meet students expectations and offer a solid knowledge to better work within the field of respiratory physiotherapy. It is also a way to promote the profession of respiratory physiotherapy in Italy

The Penetration–Aspiration Scale: Adaptation to Open Partial Laryngectomy and Reliability Analysis

A standard for assessing swallowing function after open partial horizontal laryngectomy (OPHL) is still not established. The variability in the measures used to investigate swallowing functional outcomes after OPHL limits the communication among clinicians and the possibility to compare and combine results from different studies. The study aims to adapt the PAS to the altered anatomy after OPHLs using fiberoptic endoscopic evaluation of swallowing (FEES) and to test its reliability. To adapt the PAS, two landmarks were identified: the entry of the laryngeal vestibule and the neoglottis. Ninety patients who underwent an OPHL were recruited (27 type I, 31 type II and 32 type III). FEES was performed and video-recorded. Two speech and language therapists (SLTs) independently rated each FEES using the PAS adapted for OPHL (OPHL-PAS). FEES recordings were rated for a second time by both SLTs at least 15 days from the first video analysis. Inter- and intra-rater agreement was assessed using unweighted Cohen's kappa. Overall, inter-rater agreement of the OPHL-PAS was k\u2009=\u20090.863, while intra-rater agreement was k\u2009=\u20090.854. Concerning different OPHL types, inter- and intra-rater agreement were k\u2009=\u20090.924 and k\u2009=\u20090.914 for type I, k\u2009=\u20090.865 and k\u2009=\u20090.790 for type II, and k\u2009=\u20090.808 and k\u2009=\u20090.858 for type III, respectively. The OPHL-PAS is a reliable scale to assess the invasion of lower airway during swallowing in patients with OPHL using FEES. The study represents the first attempt to define standard tools to assess swallowing functional outcome in this population

Four-point correlators of BPS operators in N=4 SYM at order g⁴

We study the large N degeneracy in the structure of the four-point amplitudes of ½ BPS operators of arbitrary weight k in perturbative N = 4 SYM theory. At one loop (order g2) this degeneracy manifests itself in a smaller number of independent conformal invariant functions describing the amplitude, compared to AdS5 supergravity results. To study this phenomenon at the two-loop level (order g4) we consider a particular N = 2 hypermultiplet projection of the general N = 4 amplitude. Using the formalism of N = 2 harmonic superspace we then explicitly compute this four-point correlator at two loops and identify the corresponding conformal invariant functions. In the cases of ½ BPS operators of weight k = 3 and k = 4 the one-loop large N degeneracy is lifted by the two-loop corrections. However, for weight k > 4 the degeneracy is still there at the two-loop level. This behavior suggests that for a given weight k the degeneracy will be removed if perturbative corrections of sufficiently high order are taken into account. These results are in accord with the AdS/CFT duality conjecture

Four-point correlators of BPS operators in N=4 SYM at order g^4

We study the large N degeneracy in the structure of the four-point amplitudes of 1/2-BPS operators of arbitrary weight k in perturbative N=4 SYM theory. At one loop (order g^2) this degeneracy manifests itself in a smaller number of independent conformal invariant functions describing the amplitude, compared to AdS_5 supergravity results. To study this phenomenon at the two-loop level (order g^4) we consider a particular N=2 hypermultiplet projection of the general N=4 amplitude. Using the formalism of N=2 harmonic superspace we then explicitly compute this four-point correlator at two loops and identify the corresponding conformal invariant functions. In the cases of 1/2-BPS operators of weight k=3 and k=4 the one-loop large N degeneracy is lifted by the two-loop corrections. However, for weight k > 4 the degeneracy is still there at the two-loop level. This behavior suggests that for a given weight k the degeneracy will be removed if perturbative corrections of sufficiently high order are taken into account. These results are in accord with the AdS/CFT duality conjecture.Comment: 45 pages, latex, 14 figure