Generalized contexts for reaction systems: definition and study of dynamic causalities

Reaction systems are a qualitative formalism for the modelling of systems of biochemical reactions. In their original formulation, a reaction system executes in an environment (or context) that can supply it with new objects at each evolution step. The context drives the behaviour of a reaction system: it can provide different inputs to the system that can lead to different behaviours. In order to more faithfully deal with open systems, in this paper we propose a more powerful notion of context having not only the capability to provide objects, but also to absorb (or remove) objects at each evolution step. For such reaction systems with generalized context we investigate properties of dynamic causality by revising the previously proposed concept of formula based predictor. A formula based predictor is a Boolean formula characterising all contexts that lead to the production of a certain object after a given number of steps. In this paper, we revise the theory of formula based predictors in order to deal with reaction systems executed in a context of the new kind. As applications, we show an example of interaction between biochemical pathways and a reaction system modelling cell metabolism and respiration

Investigating dynamic causalities in reaction systems

Reaction systems are a qualitative formalism for modeling systems of biochemical reactions characterized by the non-permanency of the elements: molecules disappear if not produced by any enabled reaction. Moreover, reaction systems execute in an environment that provides new molecules at each step. Brijder, Ehrenfeucht and Rozenberg investigated dynamic causalities in reaction systems by introducing the idea of predictors. A predictor of a molecule s, for a given n, is the set of molecules to be observed in the environment in order to determine whether s is produced or not by the system at step n. In this paper, we continue the investigation on dynamic causalities by defining an abstract interpretation framework containing three different notions of predictor: Formula based predictors, that is a propositional logic formula that precisely characterizes environments that lead to the production of s after n steps; Multi-step based predictors, that consist of n sets of molecules to be observed in the environment, one for each step; and Set based predictors, that are those proposed by Brijder, Ehrenfeucht and Rozenberg, and consist of a unique set of molecules to be observed in all steps. For each kind of predictor we define an effective operator that allows predictors to be computed for any molecule s and number of steps n. The abstract interpretation framework allows us to compare the three notions of predictor in terms of precision, to relate the three defined operators and to compute minimal predictors. We also discuss a generalization of this approach that allows predictors to be defined independently of the value of n, and a tabling approach for the practical use of predictors on reaction systems models. As an application, we use predictors, generalization and tabling to give theoretical grounds to previously obtained results on a model of gene regulation

Emerging risks in smart process industry cranes survey: SAF€RA research project SPRINCE

Savremene teorije fokusirane na istraživanje incidenata pokazuju da smanjenje udela ljudskih grešaka ne može da se postigne isključivo korekcijom ponašanja zaposlenih već zahteva izvesne inovacije koje im mogu pomoći u tom cilju. Kako veći broj istraživanja pokazuje, dizalice predstavljaju izvor opasnosti kako u industriji tako i u građevinarstvu, dok je ljudska greška najčešći uzrok incidenata. Shodno tome, implementacija inovativnog sistema za navigaciju može imati veliki potencijal za unapređenje bezbednosti rada dizalica. Međutim, brzi razvoj novih tehnologija usmerenih ka unapređenju radnih uslova i okruženja, takođe predstavlja izvor rizika, koje treba uzeti u obzir i kojima treba ovladati. Projekat 'SPRINCE' (Pametne dizalice u procesnoj industriji) ima za cilj primenu rešenja za praćenje objekta u realnom vremenu sa vizuelnim povratnim informacijama i razvoj i primenu inovativnog alata koji podrazumeva definisanje i proveru indikatora za procenu uticaja organizacionih i ljudskih (vezanih za rukovaoca) faktora primenom metode studije slučaja.Current accident theories show that the solution to avoid human error cannot be based on focusing only on the correction of operators' behavior, but needs certain innovation that will help to keep an error away. Since, as evidenced by several incident surveys, cranes are the most dangerous equipment in industrial and construction sites and human error is the most frequent cause of accidents, in this frame the crane navigation system is an important and challenging component, with a great potential for safety improvement. However, as the emerging and rapid development of new technologies aims improving the working conditions and environment through solutions regarding existing well-known problems in occupational safety, their implementation also could lead to emerging hazards and risks that must be taken into account and managed. Based on these facts, SPRINCE (Smart PRocess INdustry CranEs) project aims implementing a real-time object detection solution, which deals with cranes' tracking systems and incorporates visual feedback, developing and implementing an innovative tool for evaluation of organizational and human (operator-specific) factors. These factors will be included in the risk indicators of the implemented real-time object detection solution using case studies approach

Integrating IoT technologies for an "intelligent" safety management in the process industry

Abstract IoT (Internet of Things) technologies are wide spreading in several industrial sector due to a combination of increasing technical performance together with decreasing purchase prices: thus, new tools are been evaluated for adoption in new fields of application, like safety at work. In recent years, several projects and prototypes as well as industrial solutions have been developed using IOT technologies especially to dynamically managing safety levels at complex workplaces. The aim of this study is to describe a prototype system where the so called Smart Objects (SOs) - integrating different IoT technologies- interact in a working environment through a digital platform for managing different type of hazards – e.g. involving safety of plants as well as workers - usually influencing safety levels especially in process industry. The fields of application of the proposed system vary from tracking periodic mandatory maintenance and analyzing aging of equipment, processing or containing hazardous materials, to remote tracking of hazardous conditions of workers

Ageing and creeping management in major accident plants according to seveso III directive

The focus of this paper is the management of critical equipment ageing within the context of lower and upper tier Seveso process plants, with a peculiar insight into the effectiveness of safety management systems in setting-up reliable procedure for critical element identification. Recent research studies in fact evidenced that in Europe nearly 50% of major 'loss of containment' events, arising from technical plant failures, were primarily due to ageing plant mechanisms such as erosion, corrosion and fatigue. The critical ageing elements should be included in maintenance, inspection and periodic monitoring programs in relation to their reliability, as assumed in the risk assessment and their lifetime or frequency ranges, based on their operational experience. This paper will accurately discuss how the issue of ageing is currently handled in the process industry. The methodology builds on the critical results of actual findings from the inspections on the safety management systems of major accident plants, which were performed by a working group. The primary objective is to stimulate the introduction of effective ageing management changes into the safety management of companies, by taking advantages of findings of the previous assessment and establishing proper and effective audits

HDAC inhibition is associated to valproic acid induction of early megakaryocytic markers

Valproic acid (VPA), a histone deacetylase inhibitor, causes differentiation in different cell lines and in a cell-specific manner; yet, its effect on megakaryocytic (MK) differentiation has not been studied. We evaluated whether VPA induces MK differentiation in a UT-7 cell line through histone acetylation in the GpIIIa gene region and activation of the ERK pathway. UT-7 cells, derived from megakaryoblastic leukemia, were treated with VPA at various concentrations, and the expression of differentiation markers as well as the gene expression profile was assessed. Flow cytometry, immunoblot analysis, and RT-PCR demonstrated that VPA induced the expression of the early MK markers GpIIIa (CD61) and GpIIb/IIIa (CD41) in a dose-dependent manner. The VPA-treated cells showed hyperacetylation of the histones H3 and H4; in particular, histone acetylation was found to have been associated with CD61 expression, in that the GpIIIa promoter showed H4 hyperacetylation, as demonstrated by the chromatin immunoprecipitation assay. Furthermore, activation of the ERK pathway was involved in VPA-mediated CD61/CD41 expression and in cell adhesion, as demonstrated by using the MEK/ERK inhibitor U0126. In conclusion, the capacity of VPA to commit UT-7 cells to MK differentiation is mediated by its inhibitory action on HDAC and the long-lived activation of ERK1/2

Key role of MEK/ERK pathway in sustaining tumorigenicity and in vitro radioresistance of embryonal rhabdomyosarcoma stem-like cell population

The identification of signaling pathways that affect the cancer stem-like phenotype may provide insights into therapeutic targets for combating embryonal rhabdomyosarcoma. The aim of this study was to investigate the role of the MEK/ERK pathway in controlling the cancer stem-like phenotype using a model of rhabdospheres derived from the embryonal rhabdomyosarcoma cell line (RD)

Ultralow loading electroless deposition of IrOx on nickel foam for efficient and stable water oxidation catalysis

Abstract Photocatalysis and electrolysis are crucial processes for the development of a sustainable, clean energy system, since they enable solar fuel production, such as hydrogen by water splitting, as well as CO2 reduction. In these processes efficient and robust catalysts for water oxidation are required and the reduction of employed amount of noble metals is crucial to reduce costs and increase the sustainability of the technology. To obtain extremely low iridium loading on nickel foam electrodes we have employed electroless deposition by spontaneous galvanic displacement as a simple, low cost, highly scalable technique. After deposition the Ir oxidation has been achieved by annealing in air at 250 °C. By varying the deposition parameters, an optimal condition has been achieved, with an overpotential for water oxidation of 360 mV at 10 mA cm−2 in 1.0 M KOH solution. The Ni foam coverage with Ir oxide has also a positive impact on the electrode stability, strongly decreasing the degradation rate, compared to the case of bare Ni foam. The average amount of noble metal in the best performing electrode is only 35 μg cm−2 for a 1.6 mm thick Ni foam electrode. The proposed approach is highly promising for gas diffusion electrodes, and can be implemented in electrolytic cells, as well as in fuel cells

Monitoring Equipment Corrosion due to Sour Crude Oils: a Bayesian Approach

Sour crude oils, featuring high sulphur content and high acidity, have low costs and high availability. Although processing is more difficult, these oils represent a good opportunity for many refineries, but their treatment causes accelerated equipment deterioration due to corrosion. This work focuses on the control of corrosion due to sulphur, which is one of the most important damage mechanisms triggering random ruptures. A Bayesian Belief Network (BBN) has been developed to control the risk of release due to random ruptures. The rules used in developing the BBN are the relationships amongst parameters described in the API guidelines for the calculation of the corrosion rate. The temperature, sulphur content and acidity for a set of online hangers have been measured for a month. The BBN provides a stress indicator for the equipment, which is updated by the last-minute changes, according to the characteristics of the feed and the operating parameters. The indicator allows updating the residual useful lifetime (RUL) and can be used for immediate choices to mitigate the effects of the aggressive feeds and is also essential to address decisions about inspections and maintenance in order to manage corrosion and prevent ruptures. The indicator could be, furthermore, used in the evaluation of the additional costs deriving from the choice of processing sour crude oils to adequately support the decision-making of the typologies of crude to be treated

Radioresistance in rhabdomyosarcomas: Much more than a question of dose

Management of rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, frequently accounting the genitourinary tract is complex and requires a multimodal therapy. In particular, as a consequence of the advancement in dose conformity technology, radiation therapy (RT) has now become the standard therapeutic option for patients with RMS. In the clinical practice, dose and timing of RT are adjusted on the basis of patients' risk stratification to reduce late toxicity and side effects on normal tissues. However, despite the substantial improvement in cure rates, local failure and recurrence frequently occur. In this review, we summarize the general principles of the treatment of RMS, focusing on RT, and the main molecular pathways and specific proteins involved into radioresistance in RMS tumors. Specifically, we focused on DNA damage/repair, reactive oxygen species, cancer stem cells, and epigenetic modifications that have been reported in the context of RMS neoplasia in both in vitro and in vivo studies. The precise elucidation of the radioresistance-related molecular mechanisms is of pivotal importance to set up new more effective and tolerable combined therapeutic approaches that can radiosensitize cancer cells to finally ameliorate the overall survival of patients with RMS, especially for the most aggressive subtypes