Experimenting an indoor bluetooth-based positioning service

The Bluetooth wireless technology is an emerging technology originally designed as a short-range connectivity solution for personal, portable, and handheld electronic devices. This paper briefly presents the functionality, and the architecture of an indoor positioning service based on this technology. Most of the design choices for the service have been strongly influenced by Bluetooth features. The effectiveness of the indoor positioning service is critically analyzed. Experimental and simulation results used for defining the policy of mobile device discovery are shown

The Shape of the Ganglion Cell plus Inner Plexiform Layers of the Normal Human Macula

PURPOSE. To use surfaces generated by two-dimensional penalized splines (2D P-splines) to characterize the shape of the macular ganglion cell plus inner plexiform layers (GCLþIPL) in a group of normal humans. METHODS. Macular images of the right eyes of 23 normal subjects ranging in age from 18 to 75 years were obtained with spectral-domain optical coherence tomography (SD-OCT). The thickness of GCLþIPL was determined by manual segmentation, areas with blood vessels were removed, and the resulting maps were fit by smooth surfaces in polar coordinates centered on the fovea. RESULTS. Smooth surfaces based on 2D P-splines could precisely represent GCLþIPL thickness data, with errors comparable to the axial resolution of the SD-OCT instrument. Metrics were developed for the size, shape, and slope of the edge of the foveal depression and size and shape of the surrounding macular ridge. The slope of the foveal edge was negatively correlated with foveal size (r ¼À0.60). The size of the macular ridge was positively correlated with foveal size (r ¼ 0.75), with a slope near unity (0.90 6 0.18). The centroids of the foveal edge and macular ridge clustered near the foveal center. The foveal edge and macular ridge were well fit by ellipses. The mean GCLþIPL thickness formed an elliptical annulus elongated by approximately 30% in the horizontal direction. CONCLUSIONS. The methods developed here provide precise characterization of retinal layers for the study of glaucoma, foveal development, and other applications. (Invest Ophthalmol Vis Sci. 2012;53:7412-7420

Treatment of osteolytic solitary painful osseous metastases with radiofrequency ablation or cryoablation: a retrospective study by propensity analysis

The present study aimed to measure the improvement in pain relief and quality of life in patients with osteolytic solitary painful bone metastasis treated by cryoablation (CA) or radiofrequency ablation (RFA). Fifty patients with solitary osteolytic painful bone metastases were retrospectively studied and selected by propensity analysis. Twenty-five patients underwent CA and the remaining twenty-five underwent RFA. Pain relief, in terms of complete response (CR), the number of patients requiring analgesia and the changes in self-rated quality of life (QoL) were measured following the two treatments. Thirty-two percent of patients treated by CA experienced a CR at 12 weeks versus 20% of patients treated by RFA. The rate of CR increased significantly with respect to baseline only in the group treated by CA. In both groups there was a significant change in the partial response with respect to baseline (36% in the CA group vs. 44% in the RFA group). The recurrence rate in the CA and RFA groups was 12% and 8%, respectively. The reduction in narcotic medication requirements with respect to baseline was only significant in the group treated by CA. A significant improvement in self-rated QoL was observed in both groups. The present study seems to suggest that CA only significantly improves the rate of CR and decreases the requirement of narcotic medications. Both CA and RFA led to an improvement in the self-rated QoL of patients after the treatments. However, the results of the present study should be considered as preliminary and to serve as a framework around which future trials may be designed

Comorbidity-adjusted relative survival in newly hospitalized heart failure patients: A population-based study

Background This study aims to identify comorbidities through various sources and assess their short-term impact on relative survival in a cohort of heart failure (HF) patients. Methods Newly hospitalized HF patients were identified from hospital discharge abstracts (HDA) of Lombardy Region, Italy, from 2008 to 2010. Charlson comorbidities were assessed using the HDA and supplemented with drug prescriptions and disease-specific exemptions. A Cox model was fit for the one-year relative survival from HF. Results The cohort consisted of 51,061 HF patients (53% women; median age 80\uc2\ua0years). After integrating information from all sources, the prevalence rates of diabetes, chronic pulmonary disease and renal disease were 27.6%, 26.2% and 14.2%, respectively. The prevalence of comorbidity increased to 78%. Survival in the HF cohort was worse with increasing number of comorbidities and was inferior to that in the reference population. Notably, the overall performance of the relative survival models was similar regardless of the strategy used to ascertain comorbidity. Conclusions Comorbidities cluster in hospitalized HF patients, and increasing comorbidity burden is associated with worse survival. Integration of a comprehensive search of electronic records to supplement HDA improves the prevalence estimates of comorbidities, although it does not improve discrimination of the risk prediction model

Treatment of Solitary Painful Osseous Metastases with Radiotherapy, Cryoablation or Combined Therapy: Propensity Matching Analysis in 175 Patients

aim of this study was to identify outcomes in pain relief and quality of life in patients with a solitary painful osseous metastasis treated by radiotherapy, cryoablation or the combination using a propensity score matching study design

A Game Theoretical study of Peering vs Transit in the Internet

International audienceWe propose a model for network optimization in a non-cooperative game setting with specific reference to the Internet connectivity. We refer to the general model shown in internal report [1], where Autonomous Systems (AS) decisions on link creation and traffic routing are strategically based on realistic interconnection costs, keeping into account the peering/transit dichotomy. Equilibria existence and convergence results were obtained in [1] only for a specific toy problem, while here we study larger scale scenarios which better fit the complex nature of the Internet. We are able to show that equilibria existence and convergence properties still hold for many possible generalizations, yet not all of them, and provide a specific example for which the system enters in a never-ending oscillation. Thanks to the use of simulations we covered those scenarios for which analytic results could not be obtained, thus analyzing a broad variety of general cases which were not studied in [1]. Simulation shows that the system, in the vast majority of cases, converges to an equilibrium. Very interestingly, even in asymmetric scenarios the equilibrium reached suggests that players tend to be symmetric with respect to the peering exchange points and send their asymmetric traffic quota via the transit service providers

Peering vs Transit: a Game Theoretical model for Autonomous Systems connectivity

International audienceWe propose a model to analyze the decisions taken by an Autonomous System (AS) when joining the Internet. We first define a realistic model for the interconnection costs incurred and then we use this cost model to perform a game theoretic analysis of the decisions related to the creation of new links in the Internet. The proposed model doesn't fall into the standard category of routing games, hence we devise new tools to solve it by exploiting peculiar properties of our game. We prove analytically the existence of multiple equilibria for specific cases, and provide an algorithm to compute the stable ones. The analysis of the model's outcome highlights the existence of a Price of Anarchy (PoA) and a Price of Stability (PoS), originated by the non-cooperative behavior of the ASes, which optimize their cost function in a selfish and decentralized manner. We further observe the presence of competition between the facilities providing either transit or peering connectivity, caused by the cost differences between these two interconnection strategies

Variance Reduction in a Dataset of Normal Macular Ganglion Cell Plus Inner Plexiform Layer Thickness Maps with Application to Glaucoma Diagnosis

To examine the similarities and differences in the shape of the macular ganglion cell plus inner plexiform layers (GCL+IPL) in a healthy human population, and seek methods to reduce population variance and improve discriminating power