Facing Critical Situations by Improved Holon-Based Event Flow

Facing critical situations means handling them with a good understanding of their complexity: this calls in turn for a class of new models as well as for associated methodologies for dealing with systemic failures. A system by our approach is merely a restriction of the cartesian automaton of the states of existence of its constituent parts. Any of such composite states becomes, by the principle of abstraction, a state in the behavior of the new system. Since any interaction among systems implies a restriction of their global cartesian state automaton, interactions represent a valuable information in order to discover a feasible criterion for eliciting new systems - albeit not “concrete" systems in the classical sense. For example relationships among systems are nothing but systems on their own, having related systems as component parts. This suggests that the very notion behind system discovery and modeling is thus inherently dynamical. Such a dynamical characterization can be shown to furnish formal and methodological instruments in order to enrich the early notion of Holons by Koestler. Holonic part-whole hierarchies, named “holarchies", require to introduce a new taxonomy for event signals in order to have the internal dynamics of systems to deal with the interface of component systems. This reduces the overall complexity by allowing to modularize and partition mutual control and feedback among hierarchically related modular systems. It is finally shown that the proposed approach allows to models a hierarchy of system failures at different levels in the holarchy, which can be effectively be used in order to analyze and prevent complex critical situations

Modelling of a Safety Instrumented System by a Biologically Inspired Modular Construct

We present an ongoing research aimed at investigating aspects of a modelling paradigm where system behaviour is modelled by biologically-inspired, concurrent and autonomous modules through a state based formalism. Such modules are named holons after the work of Arthur Koestler, since they are designed in order to host both the features of parts and wholes. Current modelling paradigms tend at emphasising the parts, but miss the notion of whole. A whole models the associative behaviour observed in the domain of interest, while the parts model the behaviour of a specific entity. Holons are aimed at filling the gap. Holons can act as parts by exhibiting the interface of the state behaviour. At the same time holons can act as wholes, by having the state machine behaviour annotated with actions and triggers which allow them to communicate with other holons, coordinating them and therefore modelling the related associative behaviour. In the paradigm, the two roles are tied together, the associative behaviour becoming recursively the behaviour of a single entity which can be composed into further wholes

Controlling hazards and safety in complex systems: a multi-layered part-whole approach to system safety

The behavior of complex dependable systems poses severe safety issues due to hazards which may result from incorrect and unpredictable behavior. In order to prevent such hazards, system behavior has to be specified and checked incrementally, in order to defeat the overall system\u2019s complexity. Modularity in system design is however not trivial due to the intrinsic monolithic nature of the control loop, typical of such systems. An additional problem is given by the fact that the current modeling paradigm tends at introducing additional interactive complexity due to the direct communication and synchronization mechanism among decomposed modules. It can be shown, however, that modular decomposition is feasible by revising the current communication and interaction paradigm. Physical interactions in physical systems denote in fact less evident conceptual structures, which host the overall interaction and synchronization knowledge among the component parts. By introducing additional system entities with the aim of hosting such knowledge in a localized and compact manner, we obtain a part-whole hierarchy of systems, called holarchy. Such systems are, at the same time, both parts and wholes within a holarchy, thus giving a formal characterization to Koestler\u2019s holons

FACING CRITICAL SITUATIONS BY IMPROVED HOLON-BASED EVENT FLOW

ABSTRACT FOR THE INTERNATIONAL SYMPOSIUM: THE ECONOMIC CRISIS: TIME FOR A PARADIGM SHIFT TOWARDS A SYSTEMS APPROAC

From the Internet of Things to Cyber-Physical Systems: The Holonic Perspective

The paper presents a distributed model for implementing Cyber-Physical Systems aimed at controlling physical entities through the Internet of Things. The model tames the inherent complexity of the task by a recursive notion of modularity which makes each module both a controller and a controlled entity. Modules are arranged along part-whole tree-like hierarchies which collectively constitute the system. The behaviour of each module is strictly local since it has visibility only on its controlled modules, but not on the module which controls it. Each behaviour can be thus checked locally at design time against safety and liveness formulas, which still hold when component holons are composed into more complex ones, thus contributing, without the need of additional checks, to the overall safety and liveness of the final system

YBX1 Modulates Drug Resistance in Liver Cancer

According to the Texas Cancer Registry, hepatocellular carcinoma (HCC) is the sixth most common cause of cancer death. In 2015, Texas had the country\u27s highest incidence rate and the fourth highest mortality rate. Texas Hispanics (87% of Mexican origin) showed the highest incidence and mortality rates compared to the overall US Hispanic population, with individuals of Mexican origin having the highest rates. The Rio Grande Valley, which is predominantly Mexican, is extremely affected by this fact, which exacerbates the need to address this issue within our community. A major challenge in improving patient therapy in liver cancer is Sorafenib resistance. Sorafenib is a tumor-suppressing drug that is used as a first-line treatment for late-stage liver cancer and is especially prescribed to patients presenting relapse and recurrence of HCC. In addition, we have identified a transcription factor, YB1, which is a common element in poorer patient outcomes across breast, colon, liver, and other types of cancer. We are proposing that YB1 plays an important role in the development of Sorafenib resistance in liver cancer. Our models to study the mechanism of the development of Sorafenib resistance are HCC cell lines from the American Type Culture Collection, enhanced with overexpression of YBX1. We analyzed the Sorafenib IC50 by performing molecular assays to validate the upregulation of drug resistance by YBX1 in HCC. Additionally, we will show that overexpression of YBX1 increases cell viability, thus cancer progression, in the presence of Sorafenib, as well as overexpression of YBX1 in the Sorafenib resistant cell lines

Modularity and part-whole compositionality for computing the state semantics of statecharts

The paper discusses modularity and compositionality issues in state-based modeling formalisms and presents related recent research results. Part-Whole Statecharts provide modular constructs to traditional Statecharts in order to allow incremental and fully reusable composition of behavioral abstractions, enforcing explicitly the coordinated systemic behavior and bringing benefits to subsequent modeling and implementation phases. The paper shows that Part-Whole Statecharts have a computable semantics, which can be specified through a constraint-driven specification method. Such a method allows to specify and verify the intended meaning of states directly at design time, thus avoiding to employ less effective verification techniques, such as exhaustive testing or model checking

Ambient seismic noise as an interesting indirect cue for the Cerithidea decollata migrations

Presence or absence of water, food availability, capability of avoiding predation, and body temperature are con- stantly changing according to the tidal excursion. In fact, more than the diurnal light-dark variation, tide is shaping the whole intertidal animal life. Therefore, physiological and behavioural systems exist to reduce the stress that the intertidal fauna may face during the unsuitable tidal phase. Cerithidea decollata is a common western Indian Ocean mangrove gastropod. It feeds on the ground at low tide, and climbs the trees two/three hours before the water arrival to avoid submersion. In spite of the irregular East African tidal pattern, it also regularly settles on trunks roughly 40 cm above the maximum level of the incoming tide. Migrations usually take place about twice a day unless at Neap Tide, when snails may remain on the dry ground. Past experiments showed that a biological clock cannot account for water level foreseeing, nor direct visual cues or chemical information from the water itself or from previous migrations have been detected. On the other hand, tidal gravity variations can be felt by the snails. Moreover, other indirect cues could be hypothesize related to a) the oceanic waves reaching the coast and the barrier reef (seismic noise), or b) the changes in ground resistivity (self potential) caused by the sea water moving close. To verify these hypotheses, an integrated geophysical survey (single-station seismic noise and self potential survey) was carried out at Mida Creek (Kenya) to characterize the local seismic wavefield in terms of its amplitude and to measure the temporal variations of the electric potential field. Final goal was to verify whether a correlation exists between the time evolution of these phenomena and the snail movements. Here we present the first results of the seismic noise measurements. Data were acquired by means of a single station all-in-one 3-directional 24-bit digital tromometer equipped with 4.5 Hz geophones. The acquisition run for 11 days (29th June, 2013 - 9th July, 2013). We assumed that the tide transgressions/regressions generate pressure fluctuations on the ground, that are locally transformed into microseismic waves at seafloor propagating inland. Therefore, we evaluated a possible correlation, in terms of decision to climb up or not, between the seismic signals amplitude fluctuations and the snails’ movements. To do so we performed: a) the analysis of the trend of the LF (0.1-2 Hz) and HF (2-60 Hz) seismic noise amplitudes, and b) the comparison of the seismic signals with the height of tide, the number of animals that climbed to the safety level, and the height that they reached during each tide cycle. The study showed an interesting similarity between the time evolution (mean value) of the LF amplitude trend and the animals’ movements. Even thought additional data should be collected to improve the results, it is the first time that a consistent physical cue other than the obvious but discarded ones (visual and chemical), has been identified that could potentially be detected by the snails as well as by other intertidal organisms