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Memory Storage (memory + storage)
Selected AbstractsToward a neuro-developmental account of the development of declarative memoryDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2008Patricia J. Bauer Abstract The study of the biological bases of memory has a long history. Based on research with patients with specific lesions and disease, animal models, and neuroimaging studies, the neural substrate that supports declarative memory in adults has been relatively well articulated. By contrast, studies of the neural bases of memory in development is in its infancy. Yet joint consideration of the processes involved in building a memory trace, and of the time course of development of the neural structures involved, has contributed to the generation of specific predictions regarding the sources of age-related change. Specifically, there are suggestions that in infancy and very early childhood, encoding and consolidation processes account for substantial age-related variance in long-term declarative memory. With development, the locus of age-related variability in the vulnerability of memory traces shifts to the later-stage processes of memory storage and retrieval. These insights are afforded by consideration of multiple levels of analysis, from the biological to the behavioral. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 19,31, 2008. [source] Early genomics of learning and memory: a reviewGENES, BRAIN AND BEHAVIOR, Issue 3 2006S. Paratore The characterization of the molecular mechanisms whereby our brain codes, stores and retrieves memories remains a fundamental puzzle in neuroscience. Despite the knowledge that memory storage involves gene induction, the identification and characterization of the effector genes has remained elusive. The completion of the Human Genome Project and a variety of new technologies are revolutionizing the way these mechanisms can be explored. This review will examine how a genomic approach can be used to dissect and analyze the complex dynamic interactions involved in gene regulation during learning and memory. This innovative approach is providing information on a new class of genes associated with learning and memory in health and disease and is elucidating new molecular targets and pathways whose pharmacological modulation may allow new therapeutic approaches for improving cognition. [source] Three-Dimensionally Ordered Gold Nanocrystal/Silica Superlattice Thin Films Synthesized via Sol,Gel Self-Assembly,ADVANCED FUNCTIONAL MATERIALS, Issue 7 2006H. Fan Abstract Nanocrystals and their ordered arrays hold many important applications in fields such as catalysis, surface-enhanced Raman spectroscopy based sensors, memory storage, and electronic and optical nanodevices. Herein, a simple and general method to synthesize ordered, three-dimensional, transparent gold nanocrystal/silica superlattice thin films by self-assembly of gold nanocrystal micelles with silica or organosilsesquioxane by spin-coating is reported. The self-assembly process is conducted under acidic sol,gel conditions (ca.,pH,2), ensuring spin-solution homogeneity and stability and facilitating the formation of ordered and transparent gold nanocrystal/silica films. The monodisperse nanocrystals are organized within inorganic host matrices as a face-centered cubic mesostructure, and characterized by transmission electron spectroscopy and X-ray diffraction. [source] Coupled ghost fluid/two-phase level set method for curvilinear body-fitted gridsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 9 2007Juntao Huang Abstract A coupled ghost fluid/two-phase level set method to simulate air/water turbulent flow for complex geometries using curvilinear body-fitted grids is presented. The proposed method is intended to treat ship hydrodynamics problems. The original level set method for moving interface flows was based on Heaviside functions to smooth all fluid properties across the interface. We call this the Heaviside function method (HFM). The HFM requires fine grids across the interface. The ghost fluid method (GFM) has been designed to explicitly enforce the interfacial jump conditions, but the implementation of the jump conditions in curvilinear grids is intricate. To overcome these difficulties a coupled GFM/HFM method was developed in which approximate jump conditions are derived for piezometric pressure and velocity and pressure gradients based on exact continuous velocity and stress and jump in momentum conditions with the jump in density maintained but continuity of the molecular and turbulent viscosities imposed. The implementation of the ghost points is such that no duplication of memory storage is necessary. The level set method is adopted to locate the air/water interface, and a fast marching method was implemented in curvilinear grids to reinitialize the level set function. Validations are performed for three tests: super- and sub-critical flow without wave breaking and an impulsive plunging wave breaking over 2D submerged bumps, and the flow around surface combatant model DTMB 5512. Comparisons are made against experimental data, HFM and single-phase level set computations. The proposed method performed very well and shows great potential to treat complicated turbulent flows related to ship flows. Copyright © 2007 John Wiley & Sons, Ltd. [source] Numerical simulation of mold filling in injection molding using a three-dimensional finite volume approachINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 2 2001Rong-yeu Chang Abstract This work presents an implicit finite volume approach to simulate the three-dimensional mold filling problems encountered during the injection molding. The described numerical model deals with the three-dimensional isothermal flow of incompressible, high-viscous Newtonian fluids with moving interfaces. The collocated finite volume method and the SIMPLE segregated algorithm are used to discretize and solve the Navier,Stokes equation. In addition, a bounded compressive high-resolution differencing scheme is adopted to solve the advection equation to capture the interface on a Eulerian framework. This approach effectively solves the flow field in terms of CPU time and memory storage as well as the complicated three-dimensional melt front topology. Several two- and three-dimensional examples are presented to validate the presented approach and illustrate its capabilities. This method can more accurately predict the critical three-dimensional phenomena encountered during mold filling than the existing Hele,Shaw analysis model. The presented numerical approach has been proven to be a highly effective and flexible tool for simulating mold filling problems. Copyright © 2001 John Wiley & Sons, Ltd. [source] Sequestration of serum response factor in the hippocampus impairs long-term spatial memoryJOURNAL OF NEUROCHEMISTRY, Issue 2 2005Pramod K. Dash Abstract The formation of long-term memory has been shown to require protein kinase-mediated gene expression. One such kinase, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), can lead to the phosphorylation of serum response factor (SRF) and Elk-1, enhancing the expression of target genes. However, a direct involvement of these transcription factors in memory storage has not been demonstrated. We have employed an oligonucleotide decoy technique to interrogate SRF and Elk-1. Previously, it has been shown that intra-amygdalal infusion of small double-stranded decoy oligonucleotides for nuclear factor-kappaB (NFkappaB) can impair long-term memory for fear-potentiated startle. Using this approach, we found that intra-hippocampal infusion of NFkappaB decoy oligonucleotides also impairs long-term spatial memory, consistent with a role for this factor in long-term memory storage. Decoy oligonucleotides containing the binding site for SRF, as confirmed by shift-western, did not influence memory acquisition but impaired long-term spatial memory. Analysis of search behavior during the transfer test revealed deficits consistent with a loss of precise platform location information. In contrast, oligonucleotides with a binding site for either Elk-1 or another target of ERK activity, SMAD3/SMAD4, did not interfere with memory formation or storage. These findings suggest that SRF-mediated gene expression is required for long-term spatial memory. [source] Near-field data compression for the far-field computation in FDTDMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2006Romain Pascaud Abstract This paper presents a technique to compress the near-field data required to compute the radiated fields using FDTD. This technique is applied to the study of a UWB planar diamond antenna. The results show a 99.8% gain in memory storage, while maintaining good accuracy: less than 1% error on the far-field radiation patterns. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1155,1157, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21553 [source] Optical properties tailoring for new devices engineering in high-gap oxidesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2010Pier Carlo Ricci Abstract Monocrystal matrices of high-gap oxides are finding increasing applications as hosts of luminescent ions, typically rare earths (RE)s. Currently, RE-doped oxyorthosilicates, aluminum perovskites, and garnets (RE2SiO5,REAlO3,RE3Al5O12) are widely used as highly efficient and fast scintillators for ,-ray detection. On the other hand, shallow or deep intragap energy levels, due to stoichiometric deviation or impurities unintentionally added in the crystals, play a counteractive role giving rise to slower scintillation decay time, reduced light yield and afterglow. The aim of this work is to show how it is possible to tailor these unwelcome outcomes and RE-ion interactions for engineering new devices for optical memory storage. In this sense, experimental results of thermo- and radio-luminescence are presented. The role of the bandgap and the location in energy of the levels due to the RE dopants and to the defects is discussed from a theoretical point of view. The feasibility in the near future of new promising transparent displays is also discussed. [source] | |||||||||||||