Checking progress with aAction priority: is it fair?

The liveness characteristics of a system are intimately related to the notion of fairness. However, the task of explicitly modelling fairness constraints is complicated in practice. To address this issue, we propose to check LTS (Labelled Transition System) models under a strong fairness assumption, which can be relaxed with the use of action priority. The combination of the two provides a novel and practical way of dealing with fairness. The approach is presented in the context of a class of liveness properties termed progress, for which it yields a particularly efficient model-checking algorithm. Progress properties cover a wide range of interesting properties of systems, while presenting a clear intuitive meaning to users

Synovial Regulatory T Cells Occupy a Discrete TCR Niche in Human Arthritis and Require Local Signals To Stabilize FOXP3 Protein Expression

Although there is great interest in harnessing the immunosuppressive potential of FOXP3+ regulatory T cells (Tregs) for treating autoimmunity, a sizeable knowledge gap exists regarding Treg fate in human disease. In juvenile idiopathic arthritis (JIA) patients, we have previously reported that atypical CD25+FOXP32 Treg-like cells uniquely populate the inflamed site. Intrigu-ingly, their proportions relative to CD25+FOXP3+ Tregs associate with arthritis course, suggesting a role in disease. The ontogeny of these FOXP32 Treg-like cells is, however, unknown. In this study, we interrogated clonal relationships between CD4+ T cell subsets in JIA, using high-throughput TCR repertoire analysis. We reveal that FOXP3+ Tregs possess highly exclusive TCRb usage from conventional T cells, in blood, and also at the inflamed site, where they are clonally expanded. Intriguingly, the repertoires of FOXP3+ Tregs in synovial fluid are highly overlapping with CD25+FOXP32 Treg-like cells, indicating fluctuations in FOXP3 expression in the inflamed joint. Furthermore, cultured synovial Tregs rapidly downregulated FOXP3 protein (but not mRNA), and this process was prevented by addition of synovial fluid from JIA patients, through an IL-6–independent mechanism. Our findings suggest that most Tregs arise from a separate lineage from conventional T cells, and that this repertoire divergence is largely maintained under chronic inflammatory conditions. We propose that subsequent Treg expansions at the inflamed site creates an environment that leads to competition for limited resources within the synovium, resulting in the destabilization of FOXP3 expression in some Tregs. The Journal of Immunology, 2015, 195: 5616–5624.

Star formation in the giant HII regions of M101

The molecular components of three giant HII regions (NGC 5461, NGC 5462, NGC 5471) in the galaxy M101 are investigated with new observations from the James Clerk Maxwell Telescope, the NRAO 12-meter, and the Owens Valley millimeter array. Of the three HII regions, only NGC 5461 had previously been detected in CO emission. We calculate preliminary values for the molecular mass of the GMCs in NGC 5461 by assuming a CO-to-H_2 factor (X factor) and then compare these values with the virial masses. We conclude that the data in this paper demonstrate for the first time that the value of X may decrease in regions with intense star formation. The molecular mass for the association of clouds in NGC 5461 is approximately 3x10^7 Mo and is accompanied by 1-2 times as much atomic mass. The observed CO emission in NGC 5461 is an order of magnitude stronger than in NGC 5462, while it was not possible to detect molecular gas toward NGC 5471 with the JCMT. An even larger ratio of atomic to molecular gas in NGC 5471 was observed, which might be attributed to efficient conversion of molecular to atomic gas. The masses of the individual clouds in NGC 5461, which are gravitationally bound, cover a range of (2-8) x 10^5 Mo, comparable with the masses of Galactic giant molecular clouds (GMCs). Higher star forming efficiencies, and not massive clouds, appear to be the prerequisite for the formation of the large number of stars whose radiation is required to produce the giant HII regions in M101.Comment: 32 pages, 5 figures, accepted for publication in the Astrophysical Journa

Verifying the Safety of a Flight-Critical System

This paper describes our work on demonstrating verification technologies on a flight-critical system of realistic functionality, size, and complexity. Our work targeted a commercial aircraft control system named Transport Class Model (TCM), and involved several stages: formalizing and disambiguating requirements in collaboration with do- main experts; processing models for their use by formal verification tools; applying compositional techniques at the architectural and component level to scale verification. Performed in the context of a major NASA milestone, this study of formal verification in practice is one of the most challenging that our group has performed, and it took several person months to complete it. This paper describes the methodology that we followed and the lessons that we learned.Comment: 17 pages, 5 figure

Abstraction and Assume-Guarantee Reasoning for Automated Software Verification

Compositional verification and abstraction are the key techniques to address the state explosion problem associated with model checking of concurrent software. A promising compositional approach is to prove properties of a system by checking properties of its components in an assume-guarantee style. This article proposes a framework for performing abstraction and assume-guarantee reasoning of concurrent C code in an incremental and fully automated fashion. The framework uses predicate abstraction to extract and refine finite state models of software and it uses an automata learning algorithm to incrementally construct assumptions for the compositional verification of the abstract models. The framework can be instantiated with different assume-guarantee rules. We have implemented our approach in the COMFORT reasoning framework and we show how COMFORT out-performs several previous software model checking approaches when checking safety properties of non-trivial concurrent programs

Engineering Graph-Based Models for Dynamic Timetable Information Systems

Many efforts have been done in the last years to model public transport timetables in order to find optimal routes. The proposed models can be classified into two types: those representing the timetable as an array, and those representing it as a graph. The array-based models have been shown to be very effective in terms of query time, while the graph-based models usually answer queries by computing shortest paths, and hence they are suitable to be used in combination with speed-up techniques developed for road networks. In this paper, we focus on the dynamic behavior of graph-based models considering the case where transportation systems are subject to delays with respect to the given timetable. We make three contributions: (i) we give a simplified and optimized update routine for the well-known time-expanded model along with an engineered query algorithm; (ii) we propose a new graph-based model tailored for handling dynamic updates; (iii) we assess the effectiveness of the proposed models and algorithms by an experimental study, which shows that both models require negligible update time and a query time which is comparable to that required by some array-based models

Large-Area Mapping at 850 Microns. I. Optimum Image Reconstruction from Chop Measurements

We present results on the optimum reconstruction of chop data taken using the Submillimeter Common-User Bolometer Array on the James Clerk Maxwell Telescope. Using an artificial data set with known noise properties, we analyze three techniques for constructing images of the sky from the chop data: Emerson Fourier deconvolution, matrix inversion, and maximum entropy reconstruction. We conclude that a matrix inversion formulation via an iterative procedure produces the best image reconstructions. We apply the three reconstruction techniques to produce maps of the calibration point source CRL 618 and the ? Ophiuchi A core at 850 ?m and use Wiener filtering to remove the high-frequency noise component from the matrix inversion method

Respuestas psicológicas disfuncionales en enfermeros de Unidades de Cuidados Intensivos: una revisión sistemática de la literatura

OBJETIVOBuscar evidencias de respuestas psicológicas disfuncionales en Enfermeros de Unidades de Terapia Intensiva, con enfoque en la ansiedad, síntomas depresivos y factores relacionados.MÉTODORevisión sistemática, con evaluación crítica y síntesis de datos de los estudios, llevada a cabo en las bases de datos CINAHL, PubMed y Scopus, en el período de 1999 hasta el presente, utilizándose los siguientes términos de investigación, individualmente o en combinación: "estado mental", "síntomas depresivos", "ansiedad", "enfermeros de UCI", "estrés post traumático", "burnout", "fatiga por compasión" y "estrés psicológico".RESULTADOFueron incluidos trece estudios cuantitativos en Inglés y Griego. Los resultados sugieren un incremento de la carga psicológica en los Enfermeros de UCI comparativamente con otras especialidades de enfermería, así como con la población en general.CONCLUSIÓNEstudios internacionales de investigación acerca de la respuesta psicológica son limitados. Estudios futuros, longitudinales y de intervención, contribuirán a una mejor comprensión del fenómeno.OBJECTIVETo systematically review evidence on dysfunctional psychological responses of Intensive Care Units nurses (ICUNs), with focus on anxiety and depressive symptoms and related factors.METHODA literature search was performed in CINAHL, PubMed and Scopus databases, from 1999 to present, along with a critical appraisal and synthesis of all relevant data. The following key words, separately and in combination, were used: "mental status" "depressive symptoms" "anxiety" "ICU nurses" "PTSD" "burnout" "compassion fatigue" "psychological distress".RESULTSThirteen quantitative studies in English and Greek were included. The results suggested increased psychological burden in ICUNs compared to other nursing specialties, as well as to the general population.CONCLUSIONSStudies investigating psychological responses of ICUNs are limited, internationally. Future longitudinal and intervention studies will contribute to a better understanding of the phenomenon.OBJETIVORever sistematicamente evidências de respostas psicológicas disfuncionais em Enfermeiros de Unidades de Cuidados Intensivos (EUCI), com foco na ansiedade, sintomas depressivos e fatores relacionados.MÉTODOFoi realizada uma pesquisa bibliográfica, com avaliação crítica e síntese de dados dos estudos, nas bases de dados da CINAHL, PubMed e Scopus, para o período de 1999 até ao presente. Foram utilizados os seguintes termos de pesquisa, individualmente ou em combinação: "estado mental" "sintomas depressivos" "ansiedade" "enfermeiros de UCI" "PTSD" "burnout" "fadiga da compaixão" "stress psicológico".RESULTADOForam incluídos treze estudos quantitativos em Inglês e Grego. Os resultados sugerem um aumento da carga psicológica nos EUCI comparativamente com outras especialidades de enfermagem, assim como com a população em geral.CONCLUSÕESEstudos internacionais de investigação sobre a resposta psicológica de EUCI são limitados. Estudos futuros, longitudinais e de intervenção, irão contribuir para uma melhor compreensão do fenômeno

Enhancing shopping experiences in smart retailing

The retailing market has undergone a paradigm-shift in the last decades, departing from its traditional form of shopping in brick-and-mortar stores towards online shopping and the establishment of shopping malls. As a result, “small” independent retailers operating in urban environments have suffered a substantial reduction of their turnover. This situation could be presumably reversed if retailers were to establish business “alliances” targeting economies of scale and engage themselves in providing innovative digital services. The SMARTBUY ecosystem realizes the concept of a “distributed shopping mall”, which allows retailers to join forces and unite in a large commercial coalition that generates added value for both retailers and customers. Along this line, the SMARTBUY ecosystem offers several novel features: (i) inventory management of centralized products and services, (ii) geo-located marketing of products and services, (iii) location-based search for products offered by neighboring retailers, and (iv) personalized recommendations for purchasing products derived by an innovative recommendation system. SMARTBUY materializes a blended retailing paradigm which combines the benefits of online shopping with the attractiveness of traditional shopping in brick-and-mortar stores. This article provides an overview of the main architectural components and functional aspects of the SMARTBUY ecosystem. Then, it reports the main findings derived from a 12 months-long pilot execution of SMARTBUY across four European cities and discusses the key technology acceptance factors when deploying alike business alliances