Memory Based Online Learning of Deep Representations from Video Streams

We present a novel online unsupervised method for face identity learning from video streams. The method exploits deep face descriptors together with a memory based learning mechanism that takes advantage of the temporal coherence of visual data. Specifically, we introduce a discriminative feature matching solution based on Reverse Nearest Neighbour and a feature forgetting strategy that detect redundant features and discard them appropriately while time progresses. It is shown that the proposed learning procedure is asymptotically stable and can be effectively used in relevant applications like multiple face identification and tracking from unconstrained video streams. Experimental results show that the proposed method achieves comparable results in the task of multiple face tracking and better performance in face identification with offline approaches exploiting future information. Code will be publicly available.Comment: arXiv admin note: text overlap with arXiv:1708.0361

Measuring logical competences and soft skills when enrolling in a university degree course

Logical abilities are a ubiquitous ingredient in all those contexts that take into account soft skills, argumentative skills or critical thinking. However, the relationship between logical models and the enhancement of these abilities is rarely explicitly considered. Two aspects of the issue are particularly critical in our opinion, namely: (i) the lack of statistically relevant data concerning these competences; (ii) the absence of reliable indices that might be used to measure and detect the possession of abilities underlying the above-mentioned soft skills. This paper aims to address both aspects of this topic by presenting the results of a research we conducted in the period October – December 2020 on students enrolled in various degree courses at the University of Florence. To the best of our knowledge, to date this is the largest available database on the subject in the Italian University System. It has been obtained by a three-stage initiative. We started from an “entrance” examination for assessing the students' initial abilities. This test comprised ten questions, each of which was centered on a specific reasoning construct. The results we have collected show that there is a widespread lack of understanding of basic patterns that are common in the everyday way of arguing. Students then underwent a short training course, using formal logic techniques in order to strengthen their abilities, and afterwards took an “exit” examination, replicating the structure and the questions difficulty of the entrance one in order to evaluate the effectiveness of the course. Results show that the training was beneficial

Chapter A structural equation model to measure logical competences

Logical abilities are a ubiquitous ingredient in all those contexts that take into account soft skills, argumentative skills or critical thinking. However, the relationship between logical models and the enhancement of these abilities is rarely explicitly considered. Two aspects of the issue are particularly critical in our opinion, namely: (i) the lack of statistically relevant data concerning these competences; (ii) the absence of reliable indices that might be used to detect and measure the possession of abilities underlying the aforementioned skills. This paper addresses both aspects of this topic by presenting the results of a research that we conducted between October and December 2020 on students enrolled in various degree courses at the University of Florence. The dataset has been collected by a three-stage initiative. We started from an entrance examination to assess the students' initial abilities. This test included ten questions, each regarding a specific aspect of logical reasoning. Then, students underwent a short training course to strengthen their knowledge of logic. At the end of the short course, students underwent a final examination to evaluate the effectiveness of the training. To verify the effectiveness of the training program we used students’ characteristics into a Structural Equation Model comparing the distribution of abilities before and after the training

Loss of phosphoserine polar group asymmetry and inhibition of cholesterol transport in Jurkat cells treated with cholesterylphosphoserine

Abstract Cholesterylphosphoserine (CPHS) is a synthetic ester of cholesterol showing immunosuppressive activity. In the present study, we have used the T cell line Jurkat to investigate its mechanism of action. CPHS incorporates into cells reaching a molar ratio of 0.23 and 3.9 with the total phospholipid and cholesterol content, without inducing necrosis or apoptosis. CPHS incorporation elicits a dose-dependent binding of fluorescein isothiocyanate-labeled annexin V, suggesting that the steroid distributes in the external leaflet of plasma membrane exposing the phosphoserine group to the external cell environment and inserting the steroid ring into the phospholipid bilayer. In agreement with a preferential steroid association with sphingolipids, CPHS is included in a Triton X-100-insoluble complex when mixed with sphingomyelin and cholesterol. CPHS incorporation inhibits the esterification of low density lipoprotein (LDL)-derived cholesterol, producing a minor influence on the endogenous synthesis of cholesterol and on the acyl-CoA:cholesterol acyltransferase activity. In this effect, CPHS is as potent as progesterone (IC50 of 3.5 μ m ). It is concluded that the insertion of cholesterylphosphoserine (CPHS) in the Jurkat plasma membrane neutralizes the asymmetric distribution of the phosphoserine group and inhibits the movement of cholesterol to the endoplasmic reticulum. As CPHS is a negatively charged steroid, this last effect may be linked to the perturbation of sphingolipid/cholesterol-based microdomains, proposed to play a role in cholesterol trafficking.—Cusinato, F., W. Habeler, F. Calderazzo, F. Nardi, and A. Bruni. Loss of phosphoserine polar group asymmetry and inhibition of cholesterol transport in Jurkat cells treated with cholesterylphosphoserine

Specification and analysis of SOC systems using COWS: a finance case study

Service-oriented computing, an emerging paradigm for distributed computing based on the use of services, is calling for the development of tools and techniques to build safe and trustworthy systems, and to analyse their behaviour. Therefore many researchers have proposed to use process calculi, a cornerstone of current foundational research on specification and analysis of concurrent and distributed systems. We illustrate this approach by focussing on COWS, a process calculus expressly designed for specifying and combining services, while modelling their dynamic behaviour. We present the calculus and one of the analysis techniques it enables, that is based on the temporal logic SocL and the associated model checker CMC. We demonstrate applicability of our tools by means of a large case study, from the financial domain, which is first specified in COWS, and then analysed by using SocL to express many significant properties and CMC to verify them

Un caso di insufficienza renale acuta e miopatia reversibili

Abstract non disponibil