Agent Based Test and Repair of Distributed Systems

This article demonstrates how to use intelligent agents for testing and repairing a distributed system, whose elements may or may not have embedded BIST (Built-In Self-Test) and BISR (Built-In Self-Repair) facilities. Agents are software modules that perform monitoring, diagnosis and repair of the faults. They form together a society whose members communicate, set goals and solve tasks. An experimental solution is presented, and future developments of the proposed approach are explored

Towards microagent based DBIST/DBISR

We present some ideas and experiments on using microagents for testing and repairing a distributed system, whose elements may or may not have embedded BIST (built in self test) and BISR (built in self repair) facilities. The microagents are software modules that perform monitoring, diagnosis and repair of the faults. They form together a society whose members communicate, set goals and solve tasks. The platforms taken into consideration for mobile tester microagents include Java Micro Edition, BREW, Symbian, PalmOS, as well as more general small scale platforms. Experimental tester agents in Java 2 Micro Edition and PalmOS are also presented, a solution that ensures portability, flexibility, but also a relatively small memory footprint

PROMON: a profile monitor of software applications

Software techniques can be efficiently used to increase the dependability of safety-critical applications. Many approaches are based on information redundancy to prevent data and code corruption during the software execution. This paper presents PROMON, a C++ library that exploits a new methodology based on the concept of “Programming by Contract” to detect system malfunctions. Resorting to assertions, pre- and post-conditions, and marginal programmer interventions, PROMON-based applications can reach high level of dependability

Cortistatin-17 and -14 exert the same endocrine activities as somatostatin in humans

Cortistatin (CST) is a neuropeptide, which binds with high affinity all somatostatin (SS) receptor subtypes and shows high structural homology with SS itself. A receptor specific for CST only, i.e., not recognized by SS, has been recently described in agreement with data reporting that not all CST actions are shared by SS. Interestingly, CST but not SS also binds ghrelin receptor (GHS-R1a) in vitro, suggesting a potential interplay between CST and ghrelin system. The aim of this study was to investigate in humans the endocrine and metabolic activities of human CST-17 in comparison with rat CST-14 that has previously been shown to exert the same endocrine actions of SS in healthy volunteers. To this aim, in six healthy male volunteers (age [median, 3rd-97th centiles]: 28.5; 23.6-34.3 years; Body Mass Index: 23.5; 21.0-25.1 kg/m2), we studied the effects of human CST-17 (2.0 μg/kg/h iv over 120 min), rat CST-14 (2.0 μg/kg/h iv over 120 min) and SS-14 (2.0 μg/kg/h iv over 120 min) on: (a) spontaneous GH, ACTH, PRL, cortisol, insulin and glucose levels; (b) the GH responses to GHRH (1.0 μg/kg iv at 0 min); (c) the GH, PRL, ACTH, cortisol, insulin and glucose responses to ghrelin (1.0 μg/kg iv at 0 min). CST-17 inhibited (p<0.01) basal GH secretion to the same extent of CST-14 and SS-14. Spontaneous PRL, ACTH and cortisol secretion were not significantly modified by CST-17, CST-14 or SS-14. CST-17 as well as CST-14 and SS-14 also inhibited (p<0.05) spontaneous insulin secretion to a similar extent. None of these peptides modified glucose levels. The GH response to GHRH was inhibited to the same extent by CST-17 (p<0.01), CST-14 (p<0.01) and SS-14 (p<0.05). The ghrelin-induced GH response was higher than that elicited by GHRH (p<0.01) and inhibited by CST-17 (p<0.05) as well as by CST-14 (p<0.05) and SS-14 (p<0.01). The PRL, ACTH and cortisol responses to ghrelin were unaffected by CST-17, CST-14 or SS-14. On the other hand, the inhibitory effect of ghrelin on insulin levels was abolished by CST-17, CST-14 or SS-14 (p<0.05) that, in turn, did not modify the ghrelin-induced increase in glucose levels. In conclusion, this study demonstrates that human CST-17 and rat CST-14 exert the same endocrine activities of SS in humans. The endocrine actions of human and rat CST therefore are likely to reflect activation of classical SS receptors

An Extended Gene Protein/Products Boolean Network Model Including Post-Transcriptional Regulation

Background: Networks Biology allows the study of complex interactions between biological systems using formal, well structured, and computationally friendly models. Several different network models can be created, depending on the type of interactions that need to be investigated. Gene Regulatory Networks (GRN) are an effective model commonly used to study the complex regulatory mechanisms of a cell. Unfortunately, given their intrinsic complexity and non discrete nature, the computational study of realistic-sized complex GRNs requires some abstractions. Boolean Networks (BNs), for example, are a reliable model that can be used to represent networks where the possible state of a node is a boolean value (0 or 1). Despite this strong simplification, BNs have been used to study both structural and dynamic properties of real as well as randomly generated GRNs. Results: In this paper we show how it is possible to include the post-transcriptional regulation mechanism (a key process mediated by small non-coding RNA molecules like the miRNAs) into the BN model of a GRN. The enhanced BN model is implemented in a software toolkit (EBNT) that allows to analyze boolean GRNs from both a structural and a dynamic point of view. The open-source toolkit is compatible with available visualization tools like Cytoscape and allows to run detailed analysis of the network topology as well as of its attractors, trajectories, and state-space. In the paper, a small GRN built around the mTOR gene is used to demonstrate the main capabilities of the toolkit. Conclusions: The extended model proposed in this paper opens new opportunities in the study of gene regulation. Several of the successful researches done with the support of BN to understand high-level characteristics of regulatory networks, can now be improved to better understand the role of post-transcriptional regulation for example as a network-wide noise-reduction or stabilization mechanism

Neuroendocrine predictors of vasoplegia after cardiopulmonary bypass

PURPOSE: Vasoplegia often complicates on-pump cardiac surgery. Systemic inflammatory response induced by extracorporeal circulation represents the major determinant, but adrenal insufficiency and postoperative vasopressin deficiency may have a role. Pathophysiological meaning of perioperative changes in endocrine markers of hydro-electrolyte balance has not still fully elucidated. Objectives of the present research study were to estimate the incidence of vasoplegia in a homogeneous cohort of not severe cardiopathic patients, to define the role of presurgical adrenal insufficiency, to evaluate copeptin and NT-proBNP trends in the perioperative. METHODS: We conducted a prospective cohort study in the cardiac intensive care unit of a tertiary referral center. We evaluated 350 consecutive patients scheduled for cardiac surgery; 55 subjects completed the study. Both standard and low-dose corticotropin stimulation tests were performed in the preoperative; copeptin and NT-proBNP were evaluated in the preoperative (T0), on day 1 (T1) and day 7 (T2) after surgery. RESULTS: Nine subjects (16.3%) developed vasoplegic syndrome with longer bypass and clamping time (p  16.9 pmol/L accurately predicted the syndrome (AUC 0.86, 95% CI 0.73–0.94; OR 1.17, 95% CI 1.04–1.32). An evident correlation was observed at 7 days postoperative between NT-proBNP and copeptin (r 0.88, 95% CI 0.8–0.93; p < 0.001). CONCLUSION: Preoperative impaired response to low-dose ACTH stimulation test is not a risk factor for post-cardiotomic vasoplegia; conversely, higher preoperative copeptin predicts the complication. On-pump cardiac surgery could be an interesting model of rapid heart failure progression

Теоретико-методологічні основи розуміння механізму правового регулювання

Метою цієї статті є аналіз напрямів наукових досліджень, що у своїй єдності формують теорію механізму правового регулювання (МПР), розкриття теоретикометодологічних проблем, які мають місце при осмисленні МПР, визначення та систематизація методологічних підходів до розуміння МПР

Four domains for concurrency

AbstractWe give four domains for concurrency in a uniform way by means of domain equations. The domains are intended for modelling the four possible combinations of linear time versus branching time, and of interleaving versus noninterleaving concurrency. We use the linear time, noninterleaved domain to give operational and denotational semantics for a simple concurrent language with recursion, and prove that O = D