Security of grid structures under disguised traffic attacks

Models of rectangular grid structures were constructed in the form of a colored Petri net. The basic model consists of a matrix of switching nodes that deliver packets to computing nodes which are attached to the matrix borders and produce and consume packets. Since grid structures are often employed to solve boundary value problems, square and torus surfaces were studied and generalized to hypercube and hypertorus in multidimensional space using a grid node that aggregates switching and computing nodes. Traffic guns were added to the models to represent traffic attacks. Simulation in CPN Tools revealed simple and dangerous traffic gun configurations, such as a traffic duel, focus, crossfire, and side shot, which bring the grid to complete deadlock at less than 5 % of the grid peak load. Comparably low gun intensity targeted to induce deadlock areas within a grid (network) is a key characteristic of disguised traffic attacks. The aim of future work will be to develop counter-measures for these attacks.     

The role of calcium-permeable AMPA receptors in disynaptic feedforward inhibition in the rat prefrontal cortex

Calcium-permeable AMPA receptors (CP-AMPARs) play an important role in synaptic transmission and plasticity, but they also can induce neuronal death under certain pathological conditions. The involvement of CP-AMPARs in the pathogenesis of many diseases of the central nervous system makes them an attractive target for selective pharmacological blockade, to prevent and relieve pathological processes. However, the practical application of selective CP-AMPAR channel blockers requires a thorough study of their effects on the functioning of neural networks under the normal conditions. The goal of this study was to clarify the role of CP-AMPARs in the regulation of firing thresholds in different types of cortical neurons, as well as their involvement in maintaining the excitation/inhibition balance in the cortex. To do this, we have investigated the effects of CP-AMPARs blockade on the amplitude of excitatory postsynaptic potentials (EPSPs) and the threshold of action potentials evoked by extracellular stimulation. Whole-cell current-clamp recordings were carried out from pyramidal cells and fast-spiking interneurons in the slices of rat medial prefrontal cortex. CP-AMPARs were blocked with a selective channel blocker IEM-1460 (100 μM), the dicationic derivative of adamantane. It was found that the blockade of CP-AMPARs reduced the amplitude EPSPs in interneurons but not in pyramidal cells. In addition, it reduced the firing threshold in pyramidal cells via partial suppression of feedforward inhibition. Thus, the blockade of CP-AMPA receptors shifts the balance between cortical excitation and inhibition toward excitation.     

Intraspecific variability and phylogenetic relationships of the Pleistocene shrewSorex runtonensis (Soricidae)

Intraspecific variability of the Pleistocene speciesSorex runtonensis Hinton, 1911 from different Polish and Russian (Caucasus Mts.) localities and its relationships to Recent red-toothed shrews of similar body size and mandibular morphology,S. caecutiens Laxmann, 1788 andS. tundrensis Merriam, 1990, are explained on the grounds of multivariate statistics. The remains ofS. runtonensis from different localities form a single group and differ fromS. caecutiens. They resembleS. tundrensis by the first canonical root related to a mandibular size and proportions. This may indicate thatS. runtonensis andS. tundrensis are closely related but separated components of the species complextundrensis.     

Genetic control of degradation of chlorinated benzoic acids in Arthrobacter globiformis, Corynebacterium sepedonicum and Pseudomonas cepacia strains

The strains of Arthrobacter globiformis KZT1, Corynebacterium sepedonicum KZ4 and Pseudomonas cepacia KZ2 capable of early dehalogenation and complete oxidation of 4-chloro-, 2,4-dichloro-and 2-chlorobenzoic acids, respectively, have been analyzed for the origin of the genetic control of degradation. The occurrence and molecular sizes of plasmids in all the strains have been established. Plasmid pBS1501 was shown to control 4-chlorobenzoate dehalogenation in the case of KZT1 strain. The same possibility is proposed for plasmid pBS1502 for dehalogenation of 2,4DCBA by KZ4 strain. The chromosome localization of the genes controlling oxidation of 4-hydroxybenzoate in strain KZT1 is shown. Localization of the whole set of genes responsible for 2CBA degradation in the strain KZ2 chromosome is suggested.     

Application of compression optical coherence elastography for characterization of human pericardium: A pilot study

The recent impressive progress in Compression Optical Coherence Elastography (C-OCE) demonstrated diverse biomedical applications, comprising ophthalmology, oncology, etc. High resolution of C-OCE enables spatially resolved characterization of elasticity of rather thin (thickness < 1 mm) samples, which previously was impossible. Besides Young's modulus, C-OCE enables obtaining of nonlinear stress–strain dependences for various tissues. Here, we report the first application of C-OCE to nondestructively characterize biomechanics of human pericardium, for which data of conventional tensile tests are very limited and controversial. C-OCE revealed pronounced differences among differently prepared pericardium samples. Ample understanding of the influence of chemo-mechanical treatment on pericardium biomechanics is very important because of rapidly growing usage of own patients' pericardium for replacement of aortic valve leaflets in cardio-surgery. The figure demonstrates differences in the tangent Young's modulus after glutaraldehyde-induced cross-linking for two pericardium samples. One sample was over-stretched during the preparation, which caused some damage to the tissue.     

Stimulation of Burn Wound Healing in Rats by Nanosecond Repetitive Pulsed Microwave Radiation

Biology Bulletin - The effect of nanosecond repetitive pulsed microwave radiation (RPMR, 10 GHz, 100 ns pulse duration, 8 Hz pulse repetition rate, 140 and 1500 W/cm2 peak power flux density...     

Memantine attenuates cognitive impairments after status epilepticus induced in a lithium–pilocarpine model

The capability of memantine, a noncompetitive antagonist of the NMDA receptors, to prevent impairments of cognitive functions in rats was investigated in the lithium–pilocarpine model of epilepsy. After status epilepticus, rats exhibited impaired exploratory behavior and spatial memory, and a decline of extinction of orienting behavior. Memantine administration prevented these disturbances. Thus, the blockade of the NMDA receptors immediately after status epilepticus allowed prevention of the development of the possible cognitive impairments.