University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Autaptic pacemaker mediated propagation of weak rhythmic activity across small-world neuronal networks

Abstract: We study the effects of an autapse, which is mathematically described as a self-feedback loop, on the propagation of weak, localized pacemaker activity across a Newman–Watts small-world network consisting of stochastic Hodgkin–Huxley neurons. We consider that only the pacemaker neuron, which is stimulated by a subthreshold periodic signal, has an electrical autapse that is characterized by a coupling strength and a delay time. We focus on the impact of the coupling strength, the network structure, the properties of the weak periodic stimulus, and the properties of the autapse on the transmission of localized pacemaker activity. Obtained results indicate the existence of optimal channel noise intensity for the propagation of the localized rhythm. Under optimal conditions, the autapse can significantly improve the propagation of pacemaker activity, but only for a specific range of the autaptic coupling strength. Moreover, the autaptic delay time has to be equal to the intrinsic oscillation period of the Hodgkin–Huxley neuron or its integer multiples. We analyze the inter-spike interval histogram and show that the autapse enhances or suppresses the propagation of the localized rhythm by increasing or decreasing the phase locking between the spiking of the pacemaker neuron and the weak periodic signal. In particular, when the autaptic delay time is equal to the intrinsic period of oscillations an optimal phase locking takes place, resulting in a dominant time scale of the spiking activity. We also investigate the effects of the network structure and the coupling strength on the propagation of pacemaker activity. We find that there exist an optimal coupling strength and an optimal network structure that together warrant an optimal propagation of the localized rhythm.

Chaos promotes cooperation in the spatial prisoner's dilemma game

Abstract: We introduce chaotic variations, modelled by a spatially extended Lorenz system, to the payoffs of the spatial prisoner's dilemma game and study their effects on the evolution of cooperation. We show that chaotic variations of appropriate amplitude promote cooperation over a wide range of payoff parameters at which defection is the only strategy in a sterile environment. An appropriately pronounced chaotic environment can assure permanent domination of cooperation by full anonymity of players and without the aid of secondary strategies, thus designating chaotic payoff variations as a general and stand-alone mechanism for cooperation in the spatial prisoner's dilemma game.

Observation of B-0 -> D*-tau(+)nu(tau) decay at belle

Abstract: We report an observation of the decay B-0 -> D*-tau(+)nu(tau) in a data sample containing 535x10(6) B (B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We find a signal with a significance of 5.2 sigma and measure the branching fraction B(B-0 -> D*-tau(+)nu(tau))=(2.02(-0.37)(+0.40)(stat)+/- 0.37(syst))%. This is the first observation of an exclusive B decay with a b -> c tau nu(tau) transition.

Measurement of CO2 solubility and diffusivity in poly(l-lactide) and poly(d,l-lactide-co-glycolide) by magnetic suspension balance

Abstract: The solubility of supercritical carbon dioxide (scCO2) in poly( l -lactide) and poly( d , l -lactide-co-glycolide) at different temperatures (308, 313 and 323 K) and pressures (10–30 MPa) was measured using a magnetic suspension balance. The solubility data were also used for estimating the binary diffusion coefficients. The results show a good solubility of CO2 in both polymers: up to 43% in poly( l -lactide) and 30% in poly( d , l -lactide-co-glycolide). The diffusion coefficients have high values, which verify the liquid-like solvating properties of scCO2. The diffusion coefficient depends on the quantity of gas already absorbed by the polymer; its values decrease with increasing gas concentration.