We consider the critical behavior of two-dimensional layered Ising models where the exchange couplings between neighboring layers follow hierarchical sequences. The perturbation caused by the non-periodicity could be irrelevant, relevant or marginal. For marginal sequences we have performed a detailed study, which involved analytical and numerical calculations of different surface and bulk crit...

We study the synthesis of neural coding, selective attention and perceptual decision making. A hierarchical neural architecture is proposed, which implements Bayesian integration of noisy sensory input and topdown attentional priors, leading to sound perceptual discrimination. The model offers an explicit explanation for the experimentally observed modulation that prior information in one stimu...

This paper examines the impact of different physical modes on network QoS parameters such as throughput, bit error rate, and retransmission delays. An efficient technique for the transmission of MPEG-2 bit stream over HIPERLAN/2 networks is presented that exploits the hierarchical structure of the MPEG-2 bit stream. We show that for a given video bit stream use of multiple modulation schemes ch...

Broadcasting systems have to deal with channel variability in order to offer the best spectral efficiency to the receivers. However, the transmission parameters that maximise the spectral efficiency generally leads to a large link unavailability. In this paper, we study analytically the tradeoff between spectral efficiency and coverage for various channel resource allocation strategies when bro...

Binocular rivalry is the alternating percept that can result when the two eyes see different scenes. Recent psychophysical evidence supports the notion that some aspects of binocular rivalry bear functional similarities to other bistable percepts. We build a model based on the hypothesis (Logothetis & Schall, 1989; Leopold & Logothetis, 1996; Logothetis, Leopold & Sheinberg, 1996) that alternat...

abstract introduction: interferential current is one of the most popular kinds of electrical stimulation that are used in electrotherapy. despite its clinical popularity, there have been limited studies to investigate how this stimulation protocol affects the nerve fibers. this study was aimed to develop a realistic model for the stimulation of nerve fibers by interferential currents and using ...

Word association responses in fi rst-language (L1) Spanish and secondlanguage (L2) English were investigated by means of response latencies and types of associative response produced. The primary aims were to establish whether (a) some response types are produced more often or faster than others, (b) participants’ L2 response time profi les mirror those of their L1, and (c) participants’ L2 ass...

The current therapeutic modalities achieve low response rates in human neuroblastoma, a frequent extracranial malignancy of the early childhood. We have assessed the effect of retinoids, used presently for the treatment of neuroblastoma, on the discrete steps of the MHC class I processing machinery and susceptibility of neuroblastoma cells to CTLmediated killing. We demonstrate that retinoic ac...

background and objectives:scrophularia variegata m. beib. (scrophulariaceae) is a medicinal plant, used for various inflammatory diseases in iranian traditional medicine. in the present study, we evaluated the immune modulation and antioxidant effects of the hydroalcoholic extract of s.  variegata. methods: the splenocytes were harvested from the spleen of balb/c mice and were cultured. the spl...

Controlling the self-assembly of surface-adsorbed molecules into nanostructures requires understanding physical mechanisms that act across multiple length and time scales. By combining scanning tunneling microscopy with hierarchical ab initio and statistical mechanical modeling of 1,4-substituted benzenediamine (BDA) molecules adsorbed on a gold (111) surface, we demonstrate that apparently sim...