Runtime Verification Based on Executable Models: On-the-Fly Matching of Timed Traces

Runtime verification is checking whether a system execution satisfies or violates a given correctness property. A procedure that automatically, and typically on the fly, verifies conformance of the system's behavior to the specified property is called a monitor. Nowadays, a variety of formalisms are used to express properties on observed behavior of computer systems, and a lot of methods have been proposed to construct monitors. However, it is a frequent situation when advanced formalisms and methods are not needed, because an executable model of the system is available. The original purpose and structure of the model are out of importance; rather what is required is that the system and its model have similar sets of interfaces. In this case, monitoring is carried out as follows. Two "black boxes", the system and its reference model, are executed in parallel and stimulated with the same input sequences; the monitor dynamically captures their output traces and tries to match them. The main problem is that a model is usually more abstract than the real system, both in terms of functionality and timing. Therefore, trace-to-trace matching is not straightforward and allows the system to produce events in different order or even miss some of them. The paper studies on-the-fly conformance relations for timed systems (i.e., systems whose inputs and outputs are distributed along the time axis). It also suggests a practice-oriented methodology for creating and configuring monitors for timed systems based on executable models. The methodology has been successfully applied to a number of industrial projects of simulation-based hardware verification.Comment: In Proceedings MBT 2013, arXiv:1303.037

MAINTENANCE INTERVALS PLANNING OPTIMIZATION OF NEW GENERATION AIRCRAFTS AVIONICS.

One of the major reasons of aviation accident is unsuitable maintenance program. Nowadays maintenance steering group-3, the “Operator/Manufacturer Scheduled Maintenance Development Document” is used

Indicators of the Relationship Between the Chemical Composition of Plant and Harvest Potatoes

The authors carried out long-term research on the effect of mineral fertilizers on the “Gala” potato variety in the Pavlodar region. The relationship was established between the nitrogen, phosphorus and potassium chemical composition of the potato plant in certain phases of growth and development. Various chemical and biochemical processes occur in soil and plants every second. The productivity of plants (y) depends on how the processes take place and proceed, since it is a function of the chemical composition (x) of the leaves: y = f x. The theoretical foundations of plant diagnostics are based on the role of nutrients in the formation of the crop, starting from the early stages of development. According to Yu. I. Ermokhin, the theory of this research provides information on the needs of plants, and in practice these needs must be satisfied. The authors carried out field experiments with fertilizers to obtain the sought-for connections from the low to the optimal content between the ratio of nutrients in the potato plant, which is confirmed by high correlation coefficients (r = 0.79-0.97). If the nitrogen content is higher than the optimal 4.64% in the 7-leaf phase and 4.16% in the flowering phase, then the nature of the ovary takes on a different meaning and the equation is described in a quadratic parabola form. Keywords: potato, harvest, nutrition, fertilizers, plant growt

Lithophane furcifera (Hufnagel, 1766) in Northeastern Kazakhstan (Lepidoptera, Noctuidae)

A West Palaearctic noctuid species Lithophane furcifera (Hufnagel, 1766) is reported from North-East Kazakhstan. This record is a first find of the species in Kazakhstan as well as the easternmost confirmed locality. The distribution of the species in eastern limits of its range is directly related to the distribution of its hostplants, species of the genus Alnus. The adults, male and female genitalia are illustrated

ITHOPHANE FURCIFERA (HUFNAGEL, 1766) IN NORTHEASTERN KAZAKHSTAN (LEPIDOPTERA, NOCTUIDAE)

A West Palaearctic noctuid species Lithophane furcifera (Hufnagel, 1766) is reported from North-East Kazakhstan. This record is a first find of the species in Kazakhstan as well as the easternmost confirmed locality. The distribution of the species in eastern limits of its range is directly related to the distribution of its hostplants, species of the genus Alnus. The adults, male and female genitalia are illustrated

Kv2.1 channels prevent vasomotion and safeguard myogenic reactivity in rat small superior cerebellar arteries

Vascular smooth muscle voltage-gated potassium (Kv) channels have been proposed to contribute to myogenic autoregulation. Surprisingly, in initial experiments, we observed that the Kv2 channel inhibitor stromatoxin induced vasomotion without affecting myogenic tone. Thus, we tested the hypothesis that Kv2 channels contribute to myogenic autoregulation by fine-tuning the myogenic response. Expression of Kv2 channel mRNA was determined using real-time PCR and ‘multiplex’ single-cell RT-PCR. Potassium currents were measured using the patch-clamp technique. Contractile responses of intact arteries were studied using isobaric myography. Expression of Kv2.1 but not Kv2.2 channels was detected in intact rat superior cerebellar arteries and in single smooth muscle cells. Stromatoxin, a high-affinity inhibitor of Kv2 channels, reduced smooth muscle Kv currents by 61% at saturating concentrations (EC50 36 nmol/L). Further, stromatoxin (10–100 nmol/L) induced pronounced vasomotion in 48% of the vessels studied. In vessels not exhibiting vasomotion, stromatoxin did not affect myogenic reactivity. Notably, in vessels exhibiting stromatoxin-induced vasomotion, pressure increases evoked two effects: First, they facilitated the occurrence of random vasodilations and/or vasoconstrictions, disturbing the myogenic response (24% of the vessels). Second, they modified the vasomotion by decreasing its amplitude and increasing its frequency, thereby destabilizing myogenic tone (76% of the vessels). Our study demonstrates that (i) Kv2.1 channels are the predominantly expressed Kv channels in smooth muscle cells of rat superior cerebellar arteries, and (ii) Kv2.1 channels provide a novel type of negative feedback mechanism in myogenic autoregulation by preventing vasomotion and thereby safeguarding the myogenic response

Physiology of long pranayamic breathing: Neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system

Pranayamic breathing, defined as a manipulation of breath movement, has been shown to contribute to a physiologic response characterized by the presence of decreased oxygen consumption, decreased heart rate, and decreased blood pressure, as well as increased theta wave amplitude in EEG recordings, increased parasympathetic activity accompanied by the experience of alertness and reinvigoration. The mechanism of how pranayamic breathing interacts with the nervous system affecting metabolism and autonomic functions remains to be clearly understood. It is our hypothesis that voluntary slow deep breathing functionally resets the autonomic nervous system through stretchinduced inhibitory signals and hyperpolarization currents propagated through both neural and non-neural tissue which synchronizes neural elements in the heart, lungs, limbic system and cortex. During inspiration, stretching of lung tissue produces inhibitory signals by action of slowly adapting stretch receptors (SARs) and hyperpolarization current by action of fibroblasts. Both inhibitory impulses and hyperpolarization current are known to synchronize neural elements leading to the modulation of the nervous system and decreased metabolic activity indicative of the parasympathetic state. In this paper we propose pranayama’s physiologic mechanism through a cellular and systems level perspective,involving both neural and non-neural elements. This theoretical description describes a common physiological mechanism underlying pranayama and elucidate the role of the respiratory and cardiovascular system on modulating the autonomic nervous system. Along with facilitating the design of clinical breathing techniques for the treatment of autonomic nervous system and other disorders, this model will also validate pranayama as a topic requiring more research

Systems approach to the study of stretch and arrhythmias in right ventricular failure induced in rats by monocrotaline.

We demonstrate the synergistic benefits of using multiple technologies to investigate complex multi-scale biological responses. The combination of reductionist and integrative methodologies can reveal novel insights into mechanisms of action by tracking changes of in vivo phenomena to alterations in protein activity (or vice versa). We have applied this approach to electrical and mechanical remodelling in right ventricular failure caused by monocrotaline-induced pulmonary artery hypertension in rats. We show arrhythmogenic T-wave alternans in the ECG of conscious heart failure animals. Optical mapping of isolated hearts revealed discordant action potential duration (APD) alternans. Potential causes of the arrhythmic substrate; structural remodelling and/or steep APD restitution and dispersion were observed, with specific remodelling of the Right Ventricular Outflow Tract. At the myocyte level, [Ca(2+)]i transient alternans were observed together with decreased activity, gene and protein expression of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA). Computer simulations of the electrical and structural remodelling suggest both contribute to a less stable substrate. Echocardiography was used to estimate increased wall stress in failure, in vivo. Stretch of intact and skinned single myocytes revealed no effect on the Frank-Starling mechanism in failing myocytes. In isolated hearts acute stretch-induced arrhythmias occurred in all preparations. Significant shortening of the early APD was seen in control but not failing hearts. These observations may be linked to changes in the gene expression of candidate mechanosensitive ion channels (MSCs) TREK-1 and TRPC1/6. Computer simulations incorporating MSCs and changes in ion channels with failure, based on altered gene expression, largely reproduced experimental observations

Early Hypertrophic Signals After Myocardial Stretch : Role of Reactive Oxygen Species and the Sodium/Hydrogen Exchanger

In this chapter the enhanced activity of the cardiac Na+/H+ exchanger (NHE-1) after myocardial stretch is considered a key step of the intracellular signaling pathway leading to the slow force response to stretch as well as an early signal for the development of cardiac hypertrophy.We propose that the chain of events triggered by stretch begins with the release of small amounts of angiotensin II which in turn induce the release/formation of endothelin. The actions of these hormones trigger the production of mitochondrial reactive oxygen species that enhances NHE-1 activity, causing an increment in the intracellular Na+ concentration which promotes the increase in intracellular Ca2+ concentration ([Ca2+]i) through the Na+/Ca2+ exchanger. This [Ca2+]i increase would trigger cardiac hypertrophy by activation of widely recognized Ca2+-dependent intracellular signaling pathways.Centro de Investigaciones Cardiovasculare