Automatic instantiation of abstract tests on specific configurations for large critical control systems

Computer-based control systems have grown in size, complexity, distribution and criticality. In this paper a methodology is presented to perform an abstract testing of such large control systems in an efficient way: an abstract test is specified directly from system functional requirements and has to be instantiated in more test runs to cover a specific configuration, comprising any number of control entities (sensors, actuators and logic processes). Such a process is usually performed by hand for each installation of the control system, requiring a considerable time effort and being an error prone verification activity. To automate a safe passage from abstract tests, related to the so called generic software application, to any specific installation, an algorithm is provided, starting from a reference architecture and a state-based behavioural model of the control software. The presented approach has been applied to a railway interlocking system, demonstrating its feasibility and effectiveness in several years of testing experience

Automatic instantiation of abstract tests to specific configurations for large critical control systems

Computer-based control systems have grown in size, complexity, distribution and criticality. In this paper a methodology is presented to perform an ‘abstract testing’ of such large control systems in an efficient way: an abstract test is specified directly from system functional requirements and has to be instantiated in more test runs to cover a specific configuration, comprising any number of control entities (sensors, actuators and logic processes). Such a process is usually performed by hand for each installation of the control system, requiring a considerable time effort and being an error-prone verification activity. To automate a safe passage from abstract tests, related to the so-called generic software application, to any specific installation, an algorithm is provided, starting from a reference architecture and a statebased behavioural model of the control software. The presented approach has been applied to a railway interlocking system, demonstrating its feasibility and effectiveness in several years of testing experience

Direct numerical simulations of droplet condensation

We present in this work well-resolved and accurate Direct Numerical Simulations (DNS) of droplet condensation. Despite the great scientific and industrial interest, to this day, there is not an extensive knowledge of the different processes involved in droplet condensation. Consequently, DNS should be considered as a promising tool to investigate on this phenomenon. A preliminary validation of our simulations is carried out by direct comparison with the quasi-static theory of the droplet condensation in an infinite vapour medium. Next, more complex configurations have been considered: the condensation of a moving droplet in a subcooled vapour flow and the condensation of a hemispherical droplet deposed on an isothermal flat surface. The latter represents a first step towards the understanding of the more demanding DropWise Condensation. In both configurations, the effects of the Jakob number, Ja, have been thoroughly analysed to understand how the condensation impacts on the droplet heat flux and dynamics. This has led to the definition of a particular condensation regime for the lower Ja values, hereinafter called low condensation rate regime, where the droplet heat transfer is independent of the Ja. By increasing the Ja, instead, the effects due to condensation start to grow exponentially. This regime is referred as the high condensation rate regime in this paper. Finally, some general trends for correlations on the Nusselt number and drag coefficient accounting for condensation are proposed in this study

Gender and social class inequalities in higher education: intersectional reflections on a workshop experience

This is the final version. Available on open access from Frontiers Media via the DOI in this recordData availability statement: The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.Research about the experiences of underrepresented groups in higher education (HE) demonstrates the persistence of challenges, despite policies and institutional strategies to promote inclusion. Diversity and inclusion policies have been part of the HE agenda for several decades, yet most policies and interventions focus on (a) a given, isolated identity experience (e.g., based solely on gender, social class, or ethnicity) rather than more intersectional approaches to identity; and (b) top-down interventions that do not include participants insights in their design. In this paper, we report a case study of a workshop with students at an elite university that drew on an intersectional approach to social identities (IASI), specifically, looking at gender and social class. We explore three key themes: (a) the importance of group processes, (b) the use of visual techniques, and (c) the institutional tensions and the (de)politicisation of social psychology research. Reflecting on this case study we argue that approaches to identity and inclusion in HE can benefit from intersectionality beyond the use of multi and overlapping identity and social group categories. We argue that research in this space is not neutral and needs to acknowledge researchers’ position about (a) inclusion and diversity, (b) perceptions of participants in research, and (c) the motivation and aims of institutions where the research is conducted. Finally, we discuss the theoretical and practical implications of integrating an intersectional approach within social identity research in HE when focusing on underrepresented groups.University of ExeterNational Agency for Research and Development (ANID)/Scholarship Programme/DOCTORADO BECAS CHILE/2019European Union Horizon 202

Air Pollution, Aeroallergens, and Emergency Room Visits for Acute Respiratory Diseases and Gastroenteric Disorders among Young Children in Six Italian Cities

Past studies reported evidence of associations between air pollution and respiratory symptoms and morbility for children. Few studies examined associations between air pollution and emergency room (ER) visits for wheezing, and even fewer for gastroenteric illness. We conducted a multicity analysis of the relationship between air pollution and ER visits for wheezing and gastroenteric disorders in children 0-2 years of age.BACKGROUND: Past studies reported evidence of associations between air pollution and respiratory symptoms and morbidity for children. Few studies examined associations between air pollution and emergency room (ER) visits for wheezing, and even fewer for gastroenteric illness. We conducted a multicity analysis of the relationship between air pollution and ER visits for wheezing and gastroenteric disorder in children 0-2 years of age. METHODS: We obtained ER visit records for wheezing and gastroenteric disorder from six Italian cities. A cityspecific case-crossover analysis was applied to estimate effects of particulate matter (PM), nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide, adjusting for immediate and delayed effects of temperature. Lagged effects of air pollutants up to 6 prior days were examined. The cityspecific results were combined using a random-effect meta-analysis. RESULTS: CO and SO2 were most strongly associated with wheezing, with a 2.7% increase [95% confidence interval (CI), 0.5-4.9] for a 1.04 \u3bcg/m3 increase in 7day average CO and a 3.4% (95% CI, 1.5-5.3) increase for an 8.0 \u3bcg/m3 increase in SO2. Positive associations were also found for PM with aerodynamic diameter 64 10 \u3bcg and NO2. We found a significant association between the 3day moving average CO and gastroenteric disorders [3.8% increase (95% CI, 1.0-6.8)]. When data were stratified by season, the associations were stronger in summer for wheezing and in winter for gastroenteric disorders. CONCLUSION: Air pollution is associated with triggering of wheezing and gastroenteric disorders in children 0-2 years of age; more work is needed to understand the mechanisms to help prevent wheezing in children

Morphology and connectivity of parabrachial and cortical inputs to gustatory thalamus in rats

The ventroposterior medialis parvocellularis (VPMpc) nucleus of the thalamus, the thalamic relay nucleus for gustatory sensation, receives primary input from the parabrachial nucleus, and projects to the insular cortex. To reveal the unique properties of the gustatory thalamus in comparison with archetypical sensory relay nuclei, this study examines the morphology of synaptic circuitry in the VPMpc, focusing on parabrachiothalamic driver input and corticothalamic feedback. Anterogradely visualized parabrachiothalamic fibers in the VPMpc bear large swellings. At electron microscope resolution, parabrachiothalamic axons are myelinated and make large boutons, forming multiple asymmetric, adherent, and perforated synapses onto large‐caliber dendrites and dendrite initial segments. Labeled boutons contain dense‐core vesicles, and they resemble a population of terminals within the VPMpc containing calcitonin gene‐related peptide. As is typical of primary inputs to other thalamic nuclei, parabrachiothalamic terminals are over five times larger than other inputs, while constituting only 2% of all synapses. Glomeruli and triadic arrangements, characteristic features of other sensory thalamic nuclei, are not encountered. As revealed by anterograde tracer injections into the insular cortex, corticothalamic projections in the VPMpc form a dense network of fine fibers bearing small boutons. Corticothalamic terminals within the VPMpc were also observed to synapse on cells that were retrogradely filled from the same injections. The results constitute an initial survey describing unique anatomical properties of the rodent gustatory thalamus. J. Comp. Neurol. 523:139–161, 2015. © 2014 Wiley Periodicals, Inc. Using biotinylated tract tracers and light and electron microscopy, the authors provide quantitative ultrastructural characterization of two inputs that arrive to the gustatory thalamic nucleus (ventroposterior medialis parvocellularis nucleus [VPMpc]): parabrachiothalamic axons that bring the primary input, and corticothalamic axons that provide the feedback input.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109654/1/cne23673.pd

Urban air pollution and emergency room admissions for respiratory symptoms: a case-crossover study in Palermo, Italy

<p>Abstract</p> <p>Background</p> <p>Air pollution from vehicular traffic has been associated with respiratory diseases. In Palermo, the largest metropolitan area in Sicily, urban air pollution is mainly addressed to traffic-related pollution because of lack of industrial settlements, and the presence of a temperate climate that contribute to the limited use of domestic heating plants. This study aimed to investigate the association between traffic-related air pollution and emergency room admissions for acute respiratory symptoms.</p> <p>Methods</p> <p>From January 2004 through December 2007, air pollutant concentrations and emergency room visits were collected for a case-crossover study conducted in Palermo, Sicily. Risk estimates of short-term exposures to particulate matter and gaseous ambient pollutants including carbon monoxide, nitrogen dioxide, and sulfur dioxide were calculated by using a conditional logistic regression analysis.</p> <p>Results</p> <p>Emergency departments provided data on 48,519 visits for respiratory symptoms. Adjusted case-crossover analyses revealed stronger effects in the warm season for the most part of the pollutants considered, with a positive association for PM₁₀(odds ratio = 1.039, 95% confidence interval: 1.020 - 1.059), SO₂(OR = 1.068, 95% CI: 1.014 - 1.126), nitrogen dioxide (NO₂: OR = 1.043, 95% CI: 1.021 - 1.065), and CO (OR = 1.128, 95% CI: 1.074 - 1.184), especially among females (according to an increase of 10 μg/m³in PM₁₀, NO₂, SO₂, and 1 mg/m³in CO exposure). A positive association was observed either in warm or in cold season only for PM₁₀.</p> <p>Conclusions</p> <p>Our findings suggest that, in our setting, exposure to ambient levels of air pollution is an important determinant of emergency room (ER) visits for acute respiratory symptoms, particularly during the warm season. ER admittance may be considered a good proxy to evaluate the adverse effects of air pollution on respiratory health.</p

Land cover and air pollution are associated with asthma hospitalisations:A cross-sectional study

BACKGROUND: There is increasing policy interest in the potential for vegetation in urban areas to mitigate harmful effects of air pollution on respiratory health. We aimed to quantify relationships between tree and green space density and asthma-related hospitalisations, and explore how these varied with exposure to background air pollution concentrations. METHODS: Population standardised asthma hospitalisation rates (1997-2012) for 26,455 urban residential areas of England were merged with area-level data on vegetation and background air pollutant concentrations. We fitted negative binomial regression models using maximum likelihood estimation to obtain estimates of asthma-vegetation relationships at different levels of pollutant exposure. RESULTS: Green space and gardens were associated with reductions in asthma hospitalisation when pollutant exposures were lower but had no significant association when pollutant exposures were higher. In contrast, tree density was associated with reduced asthma hospitalisation when pollutant exposures were higher but had no significant association when pollutant exposures were lower. CONCLUSIONS: We found differential effects of natural environments at high and low background pollutant concentrations. These findings can provide evidence for urban planning decisions which aim to leverage health co-benefits from environmental improvements

Interfacial Instabilities of Two-Fluid Flows

Many flows in industry and in nature are two-fluid flows of immiscible fluids. Among them, the cases of parallel flowing gas-liquid layers in plane geometry and of oil-water arranged as Core-Annular Flow (CAF) in circular pipe are deeply investigated here. These are significant configurations, respectively, for the atomization of fuel in thermal engine and for the lubricated pipelining in petroleum industry. Two-fluid flows are often unstable. Aim of this thesis is to analyze the development of instability taking into account all the typical features associated with two-fluid flows: large density and viscosity ratios, surface tension acting on the interface separating the different fluids and the different spatial scales interested by the evolution of the interface. This analysis is very complex because it is necessary to distinguish between linear and nonlinear effects, normal mode and transient growth and delicate effects of viscosity even at high Reynolds numbers. Both linear stability theory and direct numerical simulations have been used. A linear stability analysis of these flows has been worked out only recently. It has let to verify that interfacial modes are the most unstable ones and represent the leading mechanism of primary instability. Numerical simulations, based on Volume of Fluid (VOF) method, have allowed to investigate the nonlinear development of this interfacial instability that, for gas-liquid flows characterizing the atomization process, is the main responsible of breakup and droplets formation. These simulations have displayed the formation and the evolution of a new type of instability: a nonlinear single wave Kelvin-Helmholtz instability. This structure has been extensively discussed and characterized. Two different codes have been used: an in-house modified version of SURFER and GERRIS flow solver, a new generation VOF code coupling classical VOF algorithms with the adaptive mesh refinement. Regarding CAF, in order to explain the disagreement between classic results of linear modal stability analysis and some experimental findings, a nonmodal analysis has been performed. It has highlighted how the instability of this flow is governed by transient energy amplification of infinitesimal three-dimensional disturbances that lead to particular flow patterns, such as emulsifications or water drops in oil, and play an important role in transition to turbulence