Comment on "Dynamic Opinion Model and Invasion Percolation"

In J. Shao et al., PRL 103, 108701 (2009) the authors claim that a model with majority rule coarsening exhibits in d=2 a percolation transition in the universality class of invasion percolation with trapping. In the present comment we give compelling evidence, including high statistics simulations on much larger lattices, that this is not correct. and that the model is trivially in the ordinary percolation universality class.Comment: 1 pag

Fragment Rotational Distributions From The Dissociation Of NeBr2: Experimental And Classical Trajectory Studies

The Br-2 fragment rotational distributions that result from the vibrational predissociation of NeBr2 in the B electronic state have been measured for several initial vibrational levels. In each case, the rotational distributions extend to the effective energetic Limit determined by the amount of energy available (E(av1)) for disposal into the fragment rotational and translational degrees of freedom. Analysis of the data allows refinement of the NeBr2 dissociation energy; we find that D-0=70.0 +/- 1.1 cm(-1) for the X electronic state, v = 0. Both Delta v = - 1 and -2 dissociation events have been examined. For dissociation pathways with approximately the same value of E(av1) the Delta v = -2 pathways are observed to have a higher fraction of the fragment energy in rotational excitation. The overall shape of the Delta v = -1 distributions are insensitive to the value of E(av1), suggesting that a Franck-Condon model for the dissociation may have some validity, though quantitative quantum mechanical calculations demonstrate that this model does not reproduce the large degree of fragment rotational excitation. Two classical models for the dissociation also fail to reproduce the extent of fragment rotational distribution. This result is discussed in light of previous experimental and theoretical investigations, focusing on the apparent agreement of classical models with the IBr fragment rotational distributions that result from the dissociation of NeIBr. (C) 1997 American Institute of Physics

Cytoprotective effects of melatonin against amitriptyline-induced toxicity in isolated rat hepatocytes

Purpose: Amitriptyline, one of the commonly used tricyclic antidepressants, caused rare but severe hepatotoxicity in patients who received it continuously. Previous findings showed that the intermediate metabolites of amitriptyline produced by CYP450 are involved in hepatic injury. Melatonin is an antiaging and antioxidant hormone synthesized from pineal gland. The aim of present study was to evaluate the protective role of melatonin in an in vitro model of isolated rat hepatocytes. Methods: Markers such as cell viability, reactive oxygen species formation, lipid peroxidation, mitochondrial membrane potential, and hepatocytes glutathione content were evaluated every 60 minutes for 180 minutes. Results: Present results indicated that administration of 1mM of melatonin effectively reduced the cell death, ROS formation and lipid peroxidation, mitochondrial membrane potential collapse, and reduced cellular glutathione content caused by amitriptyline. Conclusion: Our results indicated that melatonin is an effective antioxidant in preventing amitriptyline-induced hepatotoxicity. We recommend further in vivo animal and clinical trial studies on the hepatoprotective effects of melatonin in patients receiving amitriptyline. © 2015 The Authors

A Network Coding Approach to Loss Tomography

Network tomography aims at inferring internal network characteristics based on measurements at the edge of the network. In loss tomography, in particular, the characteristic of interest is the loss rate of individual links and multicast and/or unicast end-to-end probes are typically used. Independently, recent advances in network coding have shown that there are advantages from allowing intermediate nodes to process and combine, in addition to just forward, packets. In this paper, we study the problem of loss tomography in networks with network coding capabilities. We design a framework for estimating link loss rates, which leverages network coding capabilities, and we show that it improves several aspects of tomography including the identifiability of links, the trade-off between estimation accuracy and bandwidth efficiency, and the complexity of probe path selection. We discuss the cases of inferring link loss rates in a tree topology and in a general topology. In the latter case, the benefits of our approach are even more pronounced compared to standard techniques, but we also face novel challenges, such as dealing with cycles and multiple paths between sources and receivers. Overall, this work makes the connection between active network tomography and network coding

Investigations of some complexes of transition metals with sulphur donor ligands.

Complexes of several bivalent metals of the first transition series, and of gold(I), with some S-donor ligands have been synthesised. A series of complexes of thiomalic acid (H0[2]CCH(SH)CH[2]CO[2]H, tmH[3]) and some divalent metals, Ni(tmH[2])[2].2H2O, Fe(tmH) (pyridine), M(tmH). nH2O (M = Mn, Fe or Co) and the salts A[M[II](tm)]. nH2O (A = Li, Na or K and M[II]= Mn, Fe, Co or Ni) has been prepared. The complexes, except of nickel(II), are air-sensitive, and were handled under nitrogen or in vacuo. One nickel(II) complex, Ni(tmH[2])[2].2H2O, has a normal magnetic moment for an octahedral complex while the others show temperature-dependence arising from weak ferromagnetic interactions. All the iron(II)-thiomalates except Fe(tmH)(py), which is antiferromagnetic, also exhibited weak ferromagnetism. The temperature variation of the magnetic moment of Co(tmH). 3H2O was typical for a distorted octahedral monomeric structure, but the remaining cobalt(II) complexes and the manganese(II) complexes also showed antiferromagnetic interaction. Octahedral configurations were assigned to all the transition metal ions from their reflectance spectra, and this, combined with the magnetic data, indicates that all except Ni(tmH[2])[2].2H2O and Co(tmH). 3H2O are polymeric. Mossbauer spectra confirmed the oxidation and spin states and distorted octahedral stereochemistry of the iron(II) complexes. From the infrared investigations it was found that the A[M[II](tm)]. nH2O complexes contain bidentate carboxylate groups and coordinated -S as -SH bands are absent, whereas M(tmH). nH2O (M = Mn or Fe) contain one free carboxylic acid group and one bidentate carboxylate group. In Ni(tmH[2])[2]. 2H2O, unionised, and coordinated, and unionised, and uncoordinated carboxylic acid groups are present. Similar investigations have been carried out with K2[Co(thiop)[2]]. H2O (thiop = thiopropionic acid), Co(cysH)[2]. 2H2O and A [Co(cys)[2]]. 3H2O (A = Li, Na or K) (cysH = cysteine). These complexes contain transition metal ions in distorted octahedral configurations, and are believed to be polymeric. Iron(II) complexes of the Schiff bases NN' -ethylenebis (monothio- acetylacetonimine), (Sacac) 2enH[2], and 2-salicylideneaminobenzenethiol, (H2Sa1ABT) have been prepared. The spin state of Fe[ (Sacac) 2en] has not been established because its magnetic moment (1.7 B.M.) is between the values expected for high-spin and low-spin iron (II). The black complex Fe(SalABT) is antiferromagnetic and is believed to have a six-coordinate structure involving bridging sulphur atoms. A number of new transition metal nitrosyls have been obtained by reaction of the above complexes with nitric oxide. The infrared spectra of the diamagnetic dinitrosyls Fe(tmH) (NO) 2, Co(tm)(NO)[2] and Fe(thiop)(NO)[2]. CH3OH suggest coordinated NO+. The related complex K[Fe(tm) ]NO. 2H2O is paramagnetic with magnetic moments close to the value expected for two unpaired electrons. It is believed that the complex contains S = 3/2 and S = 1/2 spin isomers in equilibrium. A nitrosyl Fe(trp)2NO. 2H2O, obtained by reaction of Fe(trp)[2]. H2O (trp = tryptophan) with nitric oxide, is similar in magnetic behaviour. Some complexes of gold(I) with thiomalic acid have been isolated. These are Au(tnH[2]), Na[2] [Au(tm) ], Ca[Au(tm). 2H2O and Ba[Au(tm)]. H2O. They have polymeric structures involving bridging-sulphur atoms. Reactions between thiomalatogold(I) and sulphur-containing ligands lead to the release of some or all of the coordinated thiomalic acid from thiomalatogold(I). In the reaction of glutathione and cysteine with thiomalatogold(I) polymeric, mixed ligand complexes, i. e. bis (glutathionato)mono(thiomalato) trigold(I) and (cysteinato) -(thiomalato)digold(I), were obtained. In the reaction with sodium diethyldithiocarbamate all the thiomalic acid was released and diethyldithiocarbamatogold(I) was precipitated. Albumin also produced a precipitate with thiomalatogold(I), but the thioether methionine did not

FEM-FCT Based Dynamic Simulation of Trichel Pulse Corona Discharge in Point-Plane Configuration

In this thesis, a new two-dimensional numerical solver is presented for the dynamic simulation of the Trichel pulse regime of negative corona discharge in point-plane configuration. The goal of this thesis is to simulate the corona discharge phenomenon and to improve the existing models so that the results have an acceptable compatibility with the experimentally obtained data. The numerical technique used in this thesis is a combination of Finite Element Method (FEM) and Flux Corrected Transport (FCT). These techniques are proved to be the best techniques, presented so far for solving the nonlinear hyperbolic equations that simulate corona discharge phenomenon. The simulation begins with the single-species corona discharge model and thedifferent steps of the numerical technique are tested for this simplified model. The ability of the technique to model the expected physical behaviour of ions and electric field is investigated. Then, the technique is applied to a more complicated model of corona discharge, a three-specie model, in which three ionic species exist in the air gap: electrons, and positive and negative oxygen ions. Avalanche ionization, electron attachment and ionic recombination are the three ionic reactions which this model includes. The macroscopic parameters i.e., the average corona current and the Trichelpulses period are calculated and compared with the available experimental data. The technique proves to be compatible with the available experimental results. Finally, the effects of different parameters on the Trichel pulse characteristics are investigated. The results are further compared against the available experimental data for the effect of pressure on Trichel pulse characteristics and are reported to be compatible

Session Initiation Protocol Attacks and Challenges

In recent years, Session Initiation Protocol (SIP) has become widely used in current internet protocols. It is a text-based protocol much like Hyper Text Transport Protocol (HTTP) and Simple Mail Transport Protocol (SMTP). SIP is a strong enough signaling protocol on the internet for establishing, maintaining, and terminating session. In this paper the areas of security and attacks in SIP are discussed. We consider attacks from diverse related perspectives. The authentication schemes are compared, the representative existing solutions are highlighted, and several remaining research challenges are identified. Finally, the taxonomy of SIP threat will be presented