in this work, we analyse a pair of two-dimensional coupled reaction-diusion equations known as the gray-scott model, in which spot patterns have been observed. we focus on stationary patterns, and begin by deriving the asymptotic scaling of the parameters and variables necessary for the analysis of these patterns. a complete bifurcation study of these solutions is presented. the main mathematic...

Innovations are inherently connected to knowledge transfers. The need of face-to-face contacts to transfer tacit knowledge is commonly argued to cause a regional dimension of innovative activities. The paper presents an alternative explanation based on a model of boundedly rational actors who search for knowledge. It is shown that a regional dimension exists in these processes that results from...

bile duct ligation (bdl) is shown to induce cholestasis-related liver function impairments as well as consequent cognitive dysfunctions (i.e. impaired learning and memory formation). this study investigates the effects of cholestasis (14, 21 and 28 days post bile duct ligation) on spatial and non-spatial novelty detection, using a non-associative task. male mice weighing 30-35 g were used. chol...

palmprint recognition is a new biometrics system based on physiological characteristics of the palmprint, which includes rich, stable, and unique features such as lines, points, and texture. texture is one of the most important features extracted from low resolution images. in this paper, a new local descriptor, local composition derivative pattern (lcdp) is proposed to extract smartly stronger...

The performance of geostatistical and spatial interpolation techniques for estimation of spatial variability of heavy metals and water quality mapping of groundwater resources in Ramiyan district (Golestan province- Iran) were investigated. 24 spring/well water samples were collected and the concentration of heavy metals (Ni, Co, Pb, Cd and Cu) was determined using Differential Pulse Polarograp...

Introduction: Ascorbic acid (AA) acts as an antioxidant in the Central nervous system (CNS) of the mammalians. It is released from the some nerve ending together with neurotransmitters. The results have shown that Ascorbic acid could affect learning as well as memory. In this study, we examined the effect of ICV injection of ascorbic acid on learning and memory by Morris water maze. Method: In...

Estrogen has a widespread and complex influence on brain capabilities such as learning and memory. On the other hand, hippocampus as one of the main brain structures has an important role in spatial information processing. There is some evidence on the existence of estrogen receptors in the hippocampal CA1 area. So, in this study the effect of intrahippocampal injection of estradiol benzoate on...