Abstract

Abstract
How learning occurs within Free/LibreOpen Source (FLOSS) communities and what is the dynamics of such projects (e.g. the life cycle of such projects) are very relevant questions when considering the use of FLOSS projects in a formal education setting. This paper introduces an approach based on the 3C collaboration model (communication, coordination and cooperation) to represent the collaborative learning dynamics within FLOSS communities. To explore the collaborative learning potential of FLOSS communities a number of questionnaires and interviews to selected FLOSS contributors were run. From this study a 3C collaborative model applicable to FLOSS communities was designed and discussed.

Abstract
Background and aim: Some studies suggest that narrow-band imaging (NBI) can be more accurate at diagnosing gastric intestinal metaplasia and dysplasia than white-light endoscopy (WLE) alone. We aimed to assess the real-time diagnostic validity of high resolution endoscopy with and without NBI in the diagnosis of gastric premalignant conditions and to derive a classification for endoscopic grading of gastric intestinal metaplasia (EGGIM). Methods: A multicenter prospective study (five centers: Portugal, Italy, Romania, UK, USA) was performed involving the systematic use of high resolution gastroscopes with image registry with and without NBI in a centralized informatics platform (available online). All users used the same NBI classification. Histologic result was considered the diagnostic gold standard. Results: A total of 238 patients and 1123 endoscopic biopsies were included. NBI globally increased diagnostic accuracy by 11 percentage points (NBI 94% vs. WLE 83%; P<0.001) with no difference in the identification of Helicobacter pylori gastritis (73% vs. 74%). NBI increased sensitivity for the diagnosis of intestinal metaplasia significantly (87% vs. 53%; P<0.001) and for the diagnosis of dysplasia (92% vs. 74%). The added benefit of NBI in terms of diagnostic accuracy was greater in OLGIM III/IV than in OLGIM I/II (25 percentage points vs. 15 percentage points, respectively; P<0.001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for EGGIM in the identification of extensive metaplasia was 0.98. Conclusions: In a real-time scenario, NBI demonstrates a high concordance with gastric histology, superior to WLE. Diagnostic accuracy higher than 90% suggests that routine use of NBI allows targeted instead of random biopsy samples. EGGIM also permits immediate grading of intestinal metaplasia without biopsies and merits further investigation.

Abstract
Many neurological diseases, such as Parkinson's disease and epilepsy, can significantly impair the motor function of the patients, often leading to a dramatic loss of their quality of life. Human motion analysis is regarded as fundamental towards an early diagnosis and enhanced follow-up in this type of diseases. In this contribution, we present NeuroKinect, a novel system designed for motion analysis in neurological diseases. This system includes an RGB-D camera (Microsoft Kinect) and two integrated software applications, KiT (KinecTracker) and KiMA (Kinect Motion Analyzer). The applications enable the preview, acquisition, review and management of data provided by the sensor, which are then used for motion analysis of relevant events. NeuroKinect is a portable, low-cost and markerless solution that is suitable for use in the clinical environment. Furthermore, it is able to provide quantitative support to the clinical assessment of different neurological diseases with movement impairments, as demonstrated by its usage in two different clinical routine scenarios: gait analysis in Parkinson's disease and seizure semiology analysis in epilepsy.

Abstract

Abstract
We merge the two-sided markets duopoly model of Armstrong (2006) with the nested vertical and horizontal differentiation model of Gabszewicz and Wauthy (2012), which consists of a linear city with different consumer densities on the left and on the right side of the city. In equilibrium, the high-quality platform sells at a higher price and captures a greater market share than the low-quality platform, despite the indifferent consumer being closer to the high-quality platform. The difference between market shares is lower than socially optimal. A perturbation that introduces a negligible difference between the consumer density on the left and on the right side of the city may disrupt existence of equilibrium in the model of Armstrong (2006).