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Guillermo Blanco, Alexandra Junza, Dolores Barrón
Pharmaceuticals from veterinary treatments may enter terrestrial food webs when medicated livestock are available to wildlife in supplementary feeding stations aimed at the conservation of endangered scavengers. Here, we hypothesized that the exposure risk to livestock fluoroquinolones, as indicators of pharmaceutical burden in food, is related to the variable reliance of scavengers on domestic versus wild animal carcasses. Since the misuse of broad-spectrum antibiotics is a major predisposing factor for opportunistic mycoses, we evaluated disease signs potentially associated with diet-dependent drug exposure in nestlings of two threatened vultures...
October 14, 2016: Ecotoxicology and Environmental Safety
Martin Virte, Marc Sciamanna, Krassimir Panajotov
We theoretically demonstrate the possibility to synchronize polarization chaos generated by a free-running vertical-cavity surface-emitting laser (VCSEL). We highlight two distinct synchronization regimes: 1) a high-quality synchronization regime where all polarization modes and total intensity are synchronized, which shows good robustness against parameter mismatch, and 2) a "slow time-scale" synchronization where the slower part of the dynamics-that is, the random-like hopping between the two scrolls of the chaotic attractor-synchronizes while the faster oscillations remain unsynchronized...
October 1, 2016: Optics Letters
Guanglei Wang, Ying-Cheng Lai, Celso Grebogi
Recently, the phenomenon of quantum-classical correspondence breakdown was uncovered in optomechanics, where in the classical regime the system exhibits chaos but in the corresponding quantum regime the motion is regular - there appears to be no signature of classical chaos whatsoever in the corresponding quantum system, generating a paradox. We find that transient chaos, besides being a physically meaningful phenomenon by itself, provides a resolution. Using the method of quantum state diffusion to simulate the system dynamics subject to continuous homodyne detection, we uncover transient chaos associated with quantum trajectories...
October 17, 2016: Scientific Reports
Mamta Jain, Anil Kumar, Rishabh Charan Choudhary
In this article, we have proposed an improved diagonal queue medical image steganography for patient secret medical data transmission using chaotic standard map, linear feedback shift register, and Rabin cryptosystem, for improvement of previous technique (Jain and Lenka in Springer Brain Inform 3:39-51, 2016). The proposed algorithm comprises four stages, generation of pseudo-random sequences (pseudo-random sequences are generated by linear feedback shift register and standard chaotic map), permutation and XORing using pseudo-random sequences, encryption using Rabin cryptosystem, and steganography using the improved diagonal queues...
September 9, 2016: Brain Informatics
Rainer Engelken, Farzad Farkhooi, David Hansel, Carl van Vreeswijk, Fred Wolf
Neuronal activity in the central nervous system varies strongly in time and across neuronal populations. It is a longstanding proposal that such fluctuations generically arise from chaotic network dynamics. Various theoretical studies predict that the rich dynamics of rate models operating in the chaotic regime can subserve circuit computation and learning. Neurons in the brain, however, communicate via spikes and it is a theoretical challenge to obtain similar rate fluctuations in networks of spiking neuron models...
2016: F1000Research
Małgorzata Białous, Vitalii Yunko, Szymon Bauch, Michał Ławniczak, Barbara Dietz, Leszek Sirko
We present experimental studies of the power spectrum and other fluctuation properties in the spectra of microwave networks simulating chaotic quantum graphs with violated time reversal invariance. On the basis of our data sets, we demonstrate that the power spectrum in combination with other long-range and also short-range spectral fluctuations provides a powerful tool for the identification of the symmetries and the determination of the fraction of missing levels. Such a procedure is indispensable for the evaluation of the fluctuation properties in the spectra of real physical systems like, e...
September 30, 2016: Physical Review Letters
M Bitter, V Milner
The periodically kicked rotor is a paradigm system for studying quantum effects on classically chaotic dynamics. The wave function of the quantum rotor localizes in angular momentum space, similarly to Anderson localization of the electronic wave function in disordered solids. Here, we observe dynamical localization in a system of true quantum rotors by subjecting nitrogen molecules to periodic sequences of femtosecond pulses. Exponential distribution of the molecular angular momentum-the hallmark of dynamical localization-is measured directly by means of coherent Raman scattering...
September 30, 2016: Physical Review Letters
Amin Chabchoub
Breather solutions of the nonlinear Schrödinger equation (NLSE) are known to be considered as backbone models for extreme events in the ocean as well as in Kerr media. These exact deterministic rogue wave (RW) prototypes on a regular background describe a wide range of modulation instability configurations. Alternatively, oceanic or electromagnetic wave fields can be of chaotic nature and it is known that RWs may develop in such conditions as well. We report an experimental study confirming that extreme localizations in an irregular oceanic Joint North Sea Wave Project wave field can be tracked back to originate from exact NLSE breather solutions, such as the Peregrine breather...
September 30, 2016: Physical Review Letters
S Ray, A Ghosh, S Sinha
We study the quantum dynamics of the kicked Dicke model (KDM) in terms of the Floquet operator, and we analyze the connection between chaos and thermalization in this context. The Hamiltonian map is constructed by suitably taking the classical limit of the Heisenberg equation of motion to study the corresponding phase-space dynamics, which shows a crossover from regular to chaotic motion by tuning the kicking strength. The fixed-point analysis and calculation of the Lyapunov exponent (LE) provide us with a complete picture of the onset of chaos in phase-space dynamics...
September 2016: Physical Review. E
E J Rosero, W A S Barbosa, J F Martinez Avila, A Z Khoury, J R Rios Leite
We show how two electrically coupled semiconductor lasers having optical feedback can present simultaneous antiphase correlated fast power fluctuations, and strong in-phase synchronized spikes of chaotic power drops. This quite counterintuitive phenomenon is demonstrated experimentally and confirmed by numerical solutions of a deterministic dynamical system of rate equations. The occurrence of negative and positive cross correlation between parts of a complex system according to time scales, as proved in our simple arrangement, is relevant for the understanding and characterization of collective properties in complex networks...
September 2016: Physical Review. E
Tolga Çağlar, A Nihat Berker
The chiral spin-glass Potts system with q=3 states is studied in d=2 and 3 spatial dimensions by renormalization-group theory and the global phase diagrams are calculated in temperature, chirality concentration p, and chirality-breaking concentration c, with determination of phase chaos and phase-boundary chaos. In d=3, the system has ferromagnetic, left-chiral, right-chiral, chiral spin-glass, and disordered phases. The phase boundaries to the ferromagnetic, left- and right-chiral phases show, differently, an unusual, fibrous patchwork (microreentrances) of all four (ferromagnetic, left-chiral, right-chiral, chiral spin-glass) ordered phases, especially in the multicritical region...
September 2016: Physical Review. E
Ricardo Aguilar-López, Juan L Mata-Machuca
This paper proposes a synchronization methodology of two chaotic oscillators under the framework of identical synchronization and master-slave configuration. The proposed methodology is based on state observer design under the frame of control theory; the observer structure provides finite-time synchronization convergence by cancelling the upper bounds of the main nonlinearities of the chaotic oscillator. The above is showed via an analysis of the dynamic of the so called synchronization error. Numerical experiments corroborate the satisfactory results of the proposed scheme...
2016: TheScientificWorldJournal
Andrzej Mysiak, Małgorzata Kobusiak-Prokopowicz, Konrad Kaaz, Kamila Jarczewska, Wojciech Glabisz
BACKGROUND: The theory of chaos proves a deterministic mechanism of induction of multiple complex processes previously thought to be random in nature. This research explains how these complex processes develop. The aim of the study was to test the hypothesis of the chaotic nature of myocardial electrical events during ventricular tachycardia (VT) and ventricular fibrillation (VF). METHODS: Original hardware and software was developed for digitalization of on-line electrocardiography (ECG) data, with the functions of automatic and manual identification as well as categorization of specific ventricular arrhythmias...
October 13, 2016: Cardiology Journal
Behnaz Koocheck Shooshtari, AbdolMohammad Forouzanfar, MohammadReza Molaei
In this article a non-autonomous unified chaotic system with continuous periodic switch between the Chen and Lorenz systems is introduced. Dynamical behaviors of this system are investigated. We consider the identical (complete) synchronization of the bi-directionally coupled between two identical systems of this type and then analyze its stability by estimating the entire Lyapunov characteristic exponent spectrum. Numerical and graphical works are done with Mathematica.
2016: SpringerPlus
L L Neves, L H A Monteiro
Let a neuronal population be composed of an excitatory group interconnected to an inhibitory group. In the Wilson-Cowan model, the activity of each group of neurons is described by a first-order nonlinear differential equation. The source of the nonlinearity is the interaction between these two groups, which is represented by a sigmoidal function. Such a nonlinearity makes difficult theoretical works. Here, we analytically investigate the dynamics of a pair of coupled populations described by the Wilson-Cowan model by using a linear approximation...
2016: Computational Intelligence and Neuroscience
Ewan J Hemingway, Prashant Mishra, M Cristina Marchetti, Suzanne M Fielding
We examine the scaling with activity of the emergent length scales that control the nonequilibrium dynamics of an active nematic liquid crystal, using two popular hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses, regardless of whether the active stress is extensile or contractile in nature...
September 28, 2016: Soft Matter
R S Waples
Theory and empirical estimates agree that the ratio of effective size (Ne ) to census size (N) falls roughly in the range 0·1-0·5 for most populations. In a number of marine species, however, genetic estimates of contemporary Ne /N are as much as 5-6 orders of magnitude lower. Although some mechanisms that could produce such tiny Ne /N ratios have been proposed, the subject remains controversial. This issue is important to resolve: if Ne /N can be 10(-3) or smaller, marine fish populations that are quite large could be at genetic risk...
October 7, 2016: Journal of Fish Biology
Jerzy Wojewoda, Krzysztof Czolczynski, Yuri Maistrenko, Tomasz Kapitaniak
Chimera states in the systems of coupled identical oscillators are spatiotemporal patterns in which different groups of oscillators can exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Although these states are typically observed in large ensembles of oscillators, recently it has been suggested that chimera states may occur in the systems with small numbers of oscillators. Here, considering three coupled pendula showing chaotic behavior, we find the pattern of the smallest chimera state, which is characterized by the coexistence of two synchronized and one incoherent oscillator...
October 7, 2016: Scientific Reports
Behrooz Hashemi, Saeed Safari, Mostafa Hosseini, Mahmoud Yousefifard, Elham Erfani, Alireza Baratloo, Farhad Rahmati, Maryam Motamedi, Mohammad Mehdi Forouzanfar, Iraj Najafi
CONTEXT: Crush syndrome and its potentially life-threatening complications, such as acute kidney injury (AKI), are one of the most important medical problems of disaster victims. However, today, many unanswered questions abound about the potential risk factors of crush syndrome, predictive factors of AKI, proper amount of prophylactic hydration therapy, type of fluid, time of continuing fluid, intravenous versus oral hydration, etc. Therefore, this study was designed to review the findings on Iranian nephrologist experiences in diagnosis and management of traumatic rhabdomyolysis following the last two strong earthquakes of Bam (2003) and Manjil-Rudbar (1990)...
June 2016: Archives of Trauma Research
Noella Maria Delia Pereira, Ira Shah, Shilpa Kulkarni
Opsoclonus-myoclonus-ataxia (OMA) syndrome typically presents with chaotic eye movements and myoclonus with some patients exhibiting ataxia and behavioural disturbances. The pathogenesis may be inflammatory with an infectious or paraneoplastic trigger. We present a 13-year-old HIV-infected girl who was initially started on highly active antiretroviral therapy (HAART) in March 2013 with a CD4 count of 79 cells/cumm. Initially, the patient did not comply with treatment, resulting in a CD4+ count of 77 cells/mm(3) in November 2015 and prompting a new HAART scheme comprising lamivudine, tenofovir and ritonavir-boosted atazanavir...
October 2016: Oxford Medical Case Reports
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