Perfect Information vs Random Investigation: Safety Guidelines for a Consumer in the Jungle of Product Differentiation

We present a graph-theoretic model of consumer choice, where final decisions are shown to be influenced by information and knowledge, in the form of individual awareness, discriminating ability, and perception of market structure. Building upon the distance-based Hotelling's differentiation idea, we describe the behavioral experience of several prototypes of consumers, who walk a hypothetical cognitive path in an attempt to maximize their satisfaction. Our simulations show that even consumers endowed with a small amount of information and knowledge may reach a very high level of utility. On the other hand, complete ignorance negatively affects the whole consumption process. In addition, rather unexpectedly, a random walk on the graph reveals to be a winning strategy, below a minimal threshold of information and knowledge.Comment: 27 pages, 12 figure

WORK ABILITY IN HEALTHCARE WORKERS (HCWS) AFTER BREAST CANCER: PRELIMINARY DATA OF A PILOT STUDY

Abstract – Objective: Disabilities resulting from breast cancer (BC) treatment often reduce the quality of daily life and affect working and social life. This study investigated the residual work ability in a cohort of female healthcare workers (HCWs) suffering from BC. Patients and Methods: The study analyzed a cohort of female HCW’s operating at a hospital in Southern Italy. Each HCW underwent a medical examination and routine laboratory tests and a questionnaire on the Work Ability Index (WAI) Results: Out of the 663 (100%) HCW’s undergoing health surveillance, 6% (n=40) had been affected by BC; however, only 75% (n=30) agreed to join the study. 23 (77%) worked night shifts. The average number of days of absence from work was 155.8 ±205.4 days in nurses/technicians and 128.2 ±239.7 days for doctors/biologists. The WAI score was very low in 2 (7%) cases; moderate in 9 (30%) cases, good in 7 (23%) cases and excellent in 12 (40%) HCW’s. The nursing/technical staff has lower WAI scores than the other health figures. Arm/shoulder pain, numbness, limited mobility in the upper limbs and lymphoedema were the main comorbidities reported by HCW’s which affected WAI score. Conclusions: A greater absence from work was observed in nurses and technicians compared to doctors/biologists, also justified by the different professional risks that see them perform a physically more demanding job, i.e. manual handling of loads. WAI showed lower scores in nurses/technicians than in doctors/biologists. Morbidity in the upper limbs is one of the main complications that can negatively affect any work activity. This seems to affect the return to work, evident in sick leave days and in the ability to perform tasks

Anatomy of the quantum melting of the two dimensional Wigner crystal

The Fermi liquid-Wigner crystal transition in a two dimensional electronic system is revisited with a focus on the nature of the fixed node approximation done in quantum Monte Carlo calculations. Recently, we proposed (Phys. Rev. Lett. 94, 046801 (2005)) that for intermediate densities, a hybrid phase (with the symmetry of the crystal but otherwise liquid like properties) is more stable than both the liquid and the crystal phase. Here we confirm this result both in the thermodynamic and continuum limit. The liquid-hybrid transition takes place at rs=31.5 +/- 0.5. We find that the stability of the hybrid phase with respect to the crystal one is tightly linked to its delocalized nature. We discuss the implications of our results for various transition scenarii (quantum hexatic phase, supersolid, multiple exchange, microemulsions) proposed in the literature.Comment: 14 pages, 16 figure

Riprogettazione e ristrutturazione della stazione video di Stromboli e nuovo sistema di acquisizione e trasferimento immagini da Vulcano

La sorveglianza visiva dei vulcani attivi siciliani è una delle attività dell’unità funzionale monitoraggio Sistema Poseidon dell’INGV di Catania e consiste nel monitoraggio video continuo di detti vulcani mediante stazioni permanenti. In questo lavoro è stata rappresentata l’opera di riprogettazione e ristrutturazione della stazione video di Stromboli posta in località “Il Pizzo Sopra la Fossa” in cima al vulcano Stromboli. Tale ristrutturazione è stata necessaria poiché il materiale della stazione video, ormai obsoleto e mal funzionante, non garantiva un servizio continuo, affidabile e qualitativamente accettabile. Contemporaneamente è stato progettato e messo in opera al Centro Marcello Carapezza di Vulcano un nuovo sistema automatico di acquisizione, digitalizzazione, salvataggio su memoria di massa e trasferimento in internet ed in intranet delle immagini dei vulcani Stromboli e Vulcano. Ciò è stato effettuato utilizzando un software appositamente realizzato ed una linea trasmissione dati dedicata che hanno permesso di superare i continui inconvenienti nel trasferimento di tali immagini da Lipari

Collective Charge Fluctuations in Single-Electron Processes on Nano-Networks

Using numerical modeling we study emergence of structure and structure-related nonlinear conduction properties in the self-assembled nanoparticle films. Particularly, we show how different nanoparticle networks emerge within assembly processes with molecular bio-recognition binding. We then simulate the charge transport under voltage bias via single-electron tunnelings through the junctions between nanoparticles on such type of networks. We show how the regular nanoparticle array and topologically inhomogeneous nanonetworks affect the charge transport. We find long-range correlations in the time series of charge fluctuation at individual nanoparticles and of flow along the junctions within the network. These correlations explain the occurrence of a large nonlinearity in the simulated and experimentally measured current-voltage characteristics and non-Gaussian fluctuations of the current at the electrode.Comment: 10 pages, 7 figure