Convergence of chaotic attractors due to interaction based on closeness

Exploration of coherence phenomena in ensembles of interacting dynamical systems has been in the centre of research in social, physical, biological and technological systems for decades. But, in most of the studies, either completely percolated time- and space-static networks or temporal connectivities disregarding the systems' own dynamics have been dealt with. In this work, we examine the correlation between structural and dynamical evolution in networks of interacting dynamical systems. We specifically demonstrate the scenario of convergence of a set of chaotic attractors into a single attractor as a result of sufficient interaction based on the closeness of their own states. We characterize this occurrence through different measures, and map the collective states in network parameters' space. We further validate our proposition while exposing the whole scenario for different chaotic systems, namely Lorenz and Rössler oscillators.     

Design of multistable systems via partial synchronization

Many researchers introduce schemes for designing multistable systems by coupling two identical systems. In this paper, we introduce a generalized scheme for designing multistable systems by coupling two different dynamical systems. The basic idea of the scheme is to design partial synchronization of states between the coupled systems and finding some completely initial condition-dependent constants of motion. In our scheme, we synchronize i number (\(1\le i \le m-1\)) of state variables completely and keep constant difference between j (\(1\le j\le m-1\), \(i+j=m\)) number of state variables of two coupled m-dimensional different dynamical systems to obtain multistable behaviour. We illustrate our scheme for coupled Lorenz and Lu systems. Numerical simulation results consisting of phase diagram, bifurcation diagram and maximum Lyapunov exponents are presented to show the effectiveness of our scheme.     

Development and validation of a rapid HPLC method for quantitation of SP‐141, a novel pyrido[b]indole anticancer agent,and an initial pharmacokinetic study in mice

There is an increasing interest in targeting the MDM2 oncogene for cancer therapy. SP‐141, a novel designed small molecule MDM2 inhibitor, exerts excellent in vitro and in vivo anticancer activity. To facilitate the preclinical development of this candidate anticancer agent, we have developed an HPLC method for the quantitative analysis of SP‐141. The method was validated to be precise, accurate, and specific, with a linear range of 16.2–32,400 ng/mL in plasma, 16.2–6480 ng/mL in homogenates of brain, heart, liver, kidneys, lungs, muscle and tumor, and 32.4–6480 ng/mL in spleen homogenates. The lower limit of quantification was 16.2 ng/mL in plasma and all the tissue homogenates, except for spleen homogenates, where it was 32.4 ng/mL. The intra‐ and inter‐assay precisions (coefficient of variation) were between 0.86 and 13.39%, and accuracies (relative errors) ranged from ?8.50 to 13.92%. The relative recoveries were 85.6–113.38%. SP‐141 was stable in mouse plasma, modestly plasma bound and metabolized by S9 microsomal enzymes. We performed an initial pharmacokinetic study in tumor‐bearing nude mice, demonstrating that SP‐141 has a short half‐life in plasma and wide tissue distribution. In summary, this HPLC method can be used in future preclinical and clinical investigations of SP‐141. Copyright © 2014 John Wiley & Sons, Ltd.     

On Bayesian Adaptation

We show that Bayes estimators of an unknown density can adapt to unknown smoothness of the density. We combine prior distributions on each element of a list of log spline density models of different levels of regularity with a prior on the regularity levels to obtain a prior on the union of the models in the list. If the true density of the observations belongs to the model with a given regularity, then the posterior distribution concentrates near this true density at the rate corresponding to this regularity.     

Criterion for a unique non-relativistic quark model

We have calculated the mean square charge radii of the neutron and proton, and compared them with the experimental values, to construct a unique non-relativistic quark potential model. It is shown for the first time that, contrary to general belief, it is possible to reproduce simultaneously the baryon mass spectrum and the electromagnetic sizes of neutron and proton using a single potential model. It was found necessary to add admixtures of excited states of the nucleon in the unperturbed ground state wavefunctions.     

High-field transport properties of In0.765Ga0.235As0.5P0.5

Monte-Carlo results on the velocity-field characteristics, ac diffusion-constant and thermal-noise voltages are presented for In_0.765Ga_0.235As_0.5P_0.5 at 300K. Recently available values of physical constants have been used in the calculations. The values of diffusion constants are close to those of InP but the thermal noise voltages are found to increase faster with the field. The peak velocity is 1.9 × 10⁷ cm/s and the threshold field for negative differential mobility is about 6 kV/cm.     

A Retro-Diels Alder route to Tetramethyldisilene Me2Si=SiMe2 revisited: Flow Pyrolysis of 1,1,2,2-Tetramethyl-1,2-disilacyclohex-4-ene

Reinvestigation of the flow pyrolysis of 1,1,2,2-tetramethyl-1,2-disilacyclohex-4-ene did not identify conditions under which the retro-Diels Alder reaction was the exclusive process. Extrusion of Me₂Si=SiMe₂was confirmed, but dimerization of directly extruded Me₂Si: contributes significantly to its formation. Rearrangement of 1,1,2,2-tetramethyl-1,2-disilacyclohex-4-ene to 1,1,3,3-tetramethyl-1,3-disilacyclohex-4-ene is a major process under a variety of conditions. Computational studies reduced the number of viable pathways. Both experimental and computational results point to stepwise extrusion of Me₂Si=SiMe₂ via a diradical intermediate and to linkage by one or more common intermediates of the extrusion pathway and the pathway leading to rearranged disilacyclohexene. Such a mechanism receives support from the formation of 1,2- and 1,3-disilacyclohex-4-enes, that is both the Diels-Alder product and the rearrangement product, in the addition of Me₂Si=SiMe₂ to butadiene. Dedicated to Professor Mitsuo Kira on the occasion of his being honored for his inspiring work as the recipient of the 2005 Wacker Silicon Award.     

Transition metal complexes with a polydentate Schiff base derived from 3-formylsalicylic acid and 1,2-bis(o-aminophenylthio)ethane

The reaction of 3-formylsalicylic acid with 1,2-bis(o-aminophenylthio)ethane yielded a Schiff base with eight donor centres N₂S₂O₄ of which the inner compartment is of an N₂S₂O₂ type and the outer is of the O₂O₂ type. The base forms several mononuclear homo- and hetero-dinuclear complexes: e.g. mononuclear Cu^II, Ni^II and dinuclear Cu^II, Ni^II, UO₂ ^VI complexes. Hetero-dinuclear complexes {[M]M}, where M = the inner metal ion Cu^II, Ni^II and M = the outer metal ion Pd^II, UO₂ ^VI are also reported. The complexes were characterised by elemental analyses, spectral, thermal and magnetic measurements. Dicopper and dinickel complexes exhibit subnormal magnetic moments showing spin pairing between two metal centres, via the phenolato oxygen, whereas other mono-copper and mono-nickel complexes (both mononuclear and hetero-dinuclear) show the expected magnetic behaviour for 1e and 2e, respectively. The e.s.r. spectra of copper complexes also support the above behaviour.     

O,O′-dialkyl and alkylene dithiophosphate derivatives of silver(I). X-ray crystal structure of [Ag{S2POCH2CMe2CH2O} PPh3]2 · 2H2O

Silver(I) dialkyl/alkylene dithiophosphates of the types [Ag{S₂P(OR)₂}] and [Ag{S₂P(OGO)}] (where R = –Pr ⁿ ; G = –CMe₂CH₂CHMe–, –CH₂CMe₂CH₂–, –CMe₂CMe₂– or –CH₂CH₂CHMe–) have been prepared by treating an aqueous solution of AgNO₃ with ammonia salts of the respective dithiophosphoric acid. The derivatives form 1:1 adducts readily with 2,2-bipyridine or Ph₃P in CH₂Cl₂ solution. These novel complexes have been characterized by elemental analyses, molecular weight measurements and spectral (i.r., ¹H- and ³¹P-n.m.r.) studies. The crystal structure of [Ag{S₂POCH₂CMe₂CH₂O · PPh₃]₂ · 2H₂O exhibits an unsymmetrical attachment of the silver(I) to the ligand moiety.