FAULT INJECTION BASED DEPENDABILITY ANALYSIS

In more recent years there has been a rapid increase in the use of fault tolerant systems. The majority of computer systems, even those which are not labeled as fault tolerant have some built-in fault tolerant features. Accordingly, the need for dependability evaluation tools is increasing. These tools may help the system designer in the validation of the fault tolerance specification of their systems. A portable, general purpose evaluation.environment (called DEEP, Dependability Evaluation Experimental Package) was developed for the dependability analysis of fault tolerant systems. Our objective was to design a general purpose tool both in the sense of the target machine type and fault conditions as well. A special emphasis was given to a realistic fault injection scheme. The test environment was implemented for the dependability analysis of the Mod-ular Expandable Multiprocessor SYstem MEMSY, developed at the Friedrich-Alexander University of Erlangen-Nuremberg. In the paper the developed dependability environment (DEEP) is treated. The system structure and the detailed description of the modules are introduced. The paper contains the description of the reimplementation work of the developed portable system for the master-checker simulation as well. Experimental results of the evaluation of the MEMSY system are presented

SPRINT, STAR: Két Hatékony Kezelési Protokoll Az Intenzív Osztályon Kezelt Betegek Vércukorszintjének Normoglikémiás Tartományban Tartásához

(In Hungarian) Paper P0

Hypersensitivity to Thromboxane Receptor Mediated Cerebral Vasomotion and CBF Oscillations during Acute NO-Deficiency in Rats

), NO-deficiency is often associated with activation of thromboxane receptors (TP). In the present study we hypothesized that in the absence of NO, overactivation of the TP-receptor mediated cerebrovascular signaling pathway contributes to the development of vasomotion and CBF oscillations. synthesis by ozagrel (10 mg/kg iv.) attenuated it. In isolated MCAs U-46619 in a concentration of 100 nM, which induced weak and stable contraction under physiological conditions, evoked sustained vasomotion in the absence of NO, which effect could be completely reversed by inhibition of Rho-kinase by 10 µM Y-27632.These results suggest that hypersensitivity of the TP-receptor – Rho-kinase signaling pathway contributes to the development of low frequency cerebral vasomotion which may propagate to vasospasm in pathophysiological states associated with NO-deficiency

Lymphatic mimicry in maternal endothelial cells promotes placental spiral artery remodeling

Molecular heterogeneity of endothelial cells underlies their highly-specialized functions during changing physiological conditions within diverse vascular beds. For example, placental spiral arteries (SAs) undergo remarkable remodeling to meet the ever-growing demands of the fetus-a process which is deficient in preeclampsia. The extent to which maternal endothelial cells coordinate with immune cells and pregnancy hormones to promote SA remodeling remains largely unknown. Here we found that remodeled SAs expressed the lymphatic markers PROX1, LYVE1, and VEGFR3, mimicking lymphatic identity. Uterine natural killer (uNK) cells, which are required for SA remodeling and secrete VEGFC, were both sufficient and necessary for VEGFR3 activation in vitro and in mice lacking uNK cells, respectively. Using Flt4Chy/+ mice with kinase inactive VEGFR3 and Vegfcfl/fl;Vav1-Cre mice, we demonstrated that SA remodeling required VEGFR3 signaling, and that disrupted maternal VEGFR3 signaling contributed to late-gestation fetal growth restriction. Collectively, we identified a novel instance of lymphatic mimicry by which maternal endothelial cells promote SA remodeling, furthering our understanding of the vascular heterogeneity employed for the mitigation of pregnancy complications such as fetal growth restriction and preeclampsia

Perivascular Expression and Potent Vasoconstrictor Effect of Dynorphin A in Cerebral Arteries

BACKGROUND: Numerous literary data indicate that dynorphin A (DYN-A) has a significant impact on cerebral circulation, especially under pathophysiological conditions, but its potential direct influence on the tone of cerebral vessels is obscure. The aim of the present study was threefold: 1) to clarify if DYN-A is present in cerebral vessels, 2) to determine if it exerts any direct effect on cerebrovascular tone, and if so, 3) to analyze the role of κ-opiate receptors in mediating the effect. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemical analysis revealed the expression of DYN-A in perivascular nerves of rat pial arteries as well as in both rat and human intraparenchymal vessels of the cerebral cortex. In isolated rat basilar and middle cerebral arteries (BAs and MCAs) DYN-A (1-13) and DYN-A (1-17) but not DYN-A (1-8) or dynorphin B (DYN-B) induced strong vasoconstriction in micromolar concentrations. The maximal effects, compared to a reference contraction induced by 124 mM K(+), were 115±6% and 104±10% in BAs and 113±3% and 125±9% in MCAs for 10 µM of DYN-A (1-13) and DYN-A (1-17), respectively. The vasoconstrictor effects of DYN-A (1-13) could be inhibited but not abolished by both the κ-opiate receptor antagonist nor-Binaltorphimine dihydrochloride (NORBI) and blockade of G(i/o)-protein mediated signaling by pertussis toxin. Finally, des-Tyr(1) DYN-A (2-13), which reportedly fails to activate κ-opiate receptors, induced vasoconstriction of 45±11% in BAs and 50±5% in MCAs at 10 µM, which effects were resistant to NORBI. CONCLUSION/SIGNIFICANCE: DYN-A is present in rat and human cerebral perivascular nerves and induces sustained contraction of rat cerebral arteries. This vasoconstrictor effect is only partly mediated by κ-opiate receptors and heterotrimeric G(i/o)-proteins. To our knowledge our present findings are the first to indicate that DYN-A has a direct cerebral vasoconstrictor effect and that a dynorphin-induced vascular action may be, at least in part, independent of κ-opiate receptors

A fully symbolic design and modeling of nonlinear glucose control with Control System Professional Suite (CSPS) of Mathematica

In this case study a fully symbolic design and modeling method are presented for blood glucose control of diabetic patients under intensive care using Mathematica. The analysis is based on a modified two-compartment model proposed by Bergman et al. (2). The applied feedback control law decoupling even the nonlinear model leads to a fully symbolic solution of the closed loop equations. The effectivity of the applied symbolic procedures being mostly built-in the new version of Control System Professional Suite (CSPS) Application of Mathematica have been demonstrated for controller design in case of a glucose control for treatment of diabetes mellitus and also presented for a numerical situation described in Juhász (8). The results are in good agreement with the earlier presented symbolic-numeric analysis by Benyó et al. (1)

In search of the nature of specific nucleic acid-protein interactions

The theory of "codon-amino acid coevolution" was first proposed by Woese in 1967. It suggests that there is a stereochemical matching - that is, affinity - between amino acids and certain of the base triplet sequences that code for those amino acids. We have constructed a Common Periodic Table of Codons and Amino Acids, where the Nucleic Acid Table showed perfect axial symmetry for codons and the corresponding Amino Acid Table also displayedperiodicity regarding the biochemical properties (charge and hydrophobicity) of the 20 amino acids and the position of the stop signals. The Table indicates that the middle (2 nd) amino acid in the codon has a prominent role in determining some of the structural features of the amino acids. The possibility that physical contact between codons and amino acids might exist was tested on restriction enzymes. Many recognition site-like sequences were found in the coding sequences of these enzymes and as many as 73 examples of codon-amino acid co-location were observed in the 7 known 3D structures (December 2003) of endonuclease-nucleic acid complexes. These results indicate that the smallest possible units of specific nucleic acid-protein interaction are indeed the stereochemically compatible codons and amino acids

Potential Use Of The Stochastic ICING Model In STAR Protocol

The model of the human glucose-insulin system plays an important role in several clinical treatment methods and protocols, like tight glycemic control of intensive care patients. The Intensive Control Insulin-Nutrition-Glucose (ICING) model is one of these protocols that was used for the development of the Stochastic Targeted glucose control (STAR) protocol applied as a standard of care in New Zealand and Hungary. The original ICING model uses an ordinary differential equations (ODE) for the description of the glucose-insulin metabolic system.Recent studies attempted the extension of the original ICING model with stochastic terms resulting a new stochastic differential equations model(SDE). By using the resulted of this new model (SDE) we may have the chance to improve the accuracy of ICING modeling (reduce the modelling error) which can results a better clinical treatment using STAR. In the study presented in this paper, the potential use and implementation of the stochastic version of the ICING model (SDE), was analysed and the modelling error was compared with the original version of the model using a large clinical data set including treatment records of 60 patients from Belgium, Hungary and New Zealand. The results show that the SDE model gives a smaller modeling error compared to the ICING model in most of patients.These results suggest that SDE model may be used to improve the prediction process of the blood glucose level of the ICU patients which will be an important step of the STAR protocol