Texture spectrum coupled with entropy and homogeneity image features for myocardium muscle characterization

People in middle/later age often suffer from heart muscle damage due to coronary artery disease associated to myocardial infarction. In young people, the genetic forms of cardiomyopathies (heart muscle disease) are the utmost protuberant cause of myocardial disease. Accurate early detected information regarding the myocardial tissue structure is a key answer for tracking the progress of several myocardial diseases. The present work proposes a new method for myocardium muscle texture classification based on entropy, homogeneity and on the texture unit-based texture spectrum approaches. Entropy and homogeneity are generated in moving windows of size 3x3 and 5x5 to enhance the texture features and to create the premise of differentiation of the myocardium structures. Texture is then statistically analyzed using the texture spectrum approach. Texture classification is achieved based on a fuzzy c–means descriptive classifier. The noise sensitivity of the fuzzy c–means classifier is overcome by using the image features. The proposed method is tested on a dataset of 80 echocardiographic ultrasound images in both short-axis and long-axis in apical two chamber view representations, for normal and infarct pathologies. The results established that the entropy-based features provided superior clustering results compared to homogeneity

Optimal allocation without transfer payments

Author's draft dated February 2010 issued as discussion paper by University of Exeter Business School. Final version published by Elsevier; available online at http://www.sciencedirect.com/Often an organization or government must allocate goods without collecting payment in return. This may pose a difficult problem either when agents receiving those goods have private information in regards to their values or needs. In this paper, we find an optimal mechanism to allocate goods when the designer is benevolent. While the designer cannot charge agents, he can receive a costly but wasteful signal from them. We find conditions for cases in which ignoring these costly signals by giving agents equal share (or using lotteries if the goods are indivisible) is optimal. In other cases, those that send the highest signal should receive the goods; however, we then show that there exist cases where more complicated mechanisms are superior. Also, we show that the optimal mechanism is independent of the scarcity of the goods being allocated

Innovation and Crowdsourcing Contests

In an innovation contest, an organizer seeks solutions to an innovation-related problem from a group of independent agents. Agents, who can be heterogeneous in their ability levels, exert efforts to improve their solutions, and their solution qualities are uncertain due to the innovation and evaluation processes. In this chapter, we present a general model framework that captures main features of a contest, and encompasses several existing models in the literature. Using this framework, we analyze two important decisions of the organizer: a set of awards that will be distributed to agents and whether to restrict entry to a contest or to run an open contest. We provide a taxonomy of contest literature, and discuss past and current research on innovation contests as well as a set of exciting future research directions

Cystic abdominal lymphangioma – laparoscopic approach

Clinica I Chirurgie, Clinica Universitară „Sf.Spiridon”, Universitatea de Medicină şi Farmacie „Gr.T.Popa”, Iaşi, România, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Limfangioamele chistice (LC) sunt tumori benigne rare de origine limfatică (anomalie vasculară congenitală). Cea mai frecventă localizare este regiunea craniană – faţa şi gâtul (75% - higromă chistică), regiunea axilară şi mediastinul (20%) şi 5% - alte locaţii. LC retroperitoneale reprezintă <1% dintre cazuri. Material și metode: Noi raportăm o serie din 7 cazuri de LC abdominale operate prin abord laparoscopic din 17 LC operate în ultimii 10 ani în Clinica I Chirurgie, Clinica Universitară „Sf.Spiridon”. Rezultate: Raportul femei/bărbaţi a fost de 6/1,cu vârstă medie de 35,6 ani (20-51 ani). Simptomele principale au fost durerea, distensia abdominală şi prezenţa unei formaţiuni abdominale palpabile. Pacienţii au fost supuşi examenului clinic, ultrasonografic şi CT. Diagnosticul de LC a fost suspectat preoperator numai în 3 cazuri. Explorarea laparoscopică a pus în evidenţă existenţa tumorilor retroperitoneale numai în 2 cazuri, în mezenter, în omentul mare şi mezocolon pe dreapta – cîte un caz fiecare. Noi am recurs la excizia laparoscopică a chistului cu evoluţie postoperatorie favorabilă. Dimensiunea medie a tumorii a fost de 11,4 cm. Durata medie de spitalizare a fost de 3,4 zile. Concluzii: Abordul laparoscopic este fezabil (“standardul de aur”), stabileşte diagnosticul şi permite excizia chirurgicală completă, ceea ce diminuează riscul de recidive.Introduction: Cystic lymphangioamas (CL) are rare benign tumors, with lymphatic origin (congenital vascular anomaly). It locates the most frequent cranial region – face and neck (75% - cystic hygroma), mediastinum and axilla (20%) and 5% other locations. CL retroperitoneal represents <1% of cases. Material and methods: We report a series of 7 cases of abdominal CL operated by laparoscopic approach from 17 CL operated in last 10 years in the First Surgical Clinic, “St.Spiridon” Hospital. Results: The ratio female/male was 6/1, with a mean age of 35.6 years (20-51 years). The main symptoms were pain, abdominal distension and palpable abdominal mass. Patients were examined clinically, ultrasound and CT. The diagnosis of CL was suspected preoperatively only in 3 cases. Laparoscopic exploration reveals the existence of retroperitoneal tumor in 2 cases, in mesentery, in great omentum and in right mesocolon in 1 case each. We performed laparoscopic excision of the cyst with favorable postoperative course. Mean tumor size was 11.4 cm. Mean hospital stay was 3.4 days. Conclusions: Laparoscopic approach is feasible (gold standard), certified diagnosis and allows complete surgical excision, which reduces the risk of relapse

A Top Dog Tale with Preference Complementarities

The emergence of a winner-take-all (top dog) outcome is generally due to political or institutional constraints or to specific technological features which favour the performance of just one individual. In this paper we provide a different explanation for the occurrence of a top-dog equilibrium in exchange economies. We show that once heterogeneous complementarities (i.e. Scarf’s preferences) are analysed with general endowment distributions, a variety of equilibria different from the well-known symmetric outcome with full utilisation of resources can emerge. Specifically, we show that stable corner equilibria with a winner-take-all (top dog) individual arise that are Pareto optima although the remaining individuals are no better off than with zero consumption and resources can be unused. Because of heterogenous complementarities, market mechanisms are weak and cannot overcome the top dog’s power. Voting mechanisms or taxation policies can reduce the top dog’s privileged position