Reminder cues can destabilize consolidated memories, rendering them modifiable before they return to a stable state through the process of reconsolidation. Older and stronger memories resist this process and require the presentation of reminders along with salient novel information in order to destabilize. Previously, we demonstrated in rats that novelty-induced object memory destabilization requires acetylcholine (ACh) activity at M1 muscarinic receptors. Other research predominantly has focused on glutamate, which modulates fear memory destabilization and reconsolidation through GluN2B- and GluN2A-containing NMDARs, respectively. In the current study, we demonstrate the same dissociable roles of GluN2B- and N2A-containing NMDARs in perirhinal cortex (PRh) for object memory destabilization and reconsolidation when boundary conditions are absent. However, neither GluN2 receptor subtype was required for novelty-induced destabilization of remote, resistant memories. Furthermore, GluN2B and GluN2A subunit proteins were upregulated selectively in PRh 24 h after learning, but returned to baseline by 48 h, suggesting that NMDARs, unlike muscarinic receptors, have only a temporary role in object memory destabilization. Indeed, activation of M1 receptors in PRh at the time of reactivation effectively destabilized remote memories despite inhibition of GluN2B-containing NMDARs. These findings suggest that cholinergic activity at M1 receptors overrides boundary conditions to destabilize resistant memories when other established mechanisms are insufficient. 相似文献
We have grown helical nanowire assemblies of parylene C, thereby demonstrating that polymeric sculptured thin films (STFs) can be fabricated by a combination of physical and chemical vapor deposition processes. The deposition method is explained in detail and electron micrographs of 200-400 nm size sculptured thin film of parylene are given. The shapes of the submicron and nanowire assemblies can be engineered so that the polymeric STF acts as a template for preferential attachment of biomolecules. 相似文献
This paper proposes a sequential design scheme for switching ℌ∞ LPV (Linear Parameter-Varying) control, aiming to reduce the computational complexity of the associated optimization problem. Different from the traditional approach that simultaneously designs switching LPV controllers and solves a high-dimensional optimization problem, the proposed sequential design approach renders a bundle of low-dimensional optimization problems to be solved iteratively. Individual ℌ∞ LPV controller for each subregion is synthesized by independent PLMIs (Parametric Linear Matrix Inequalities) to guarantee ℌ∞ performance, and controller variables are interpolated on the overlapped subregions such that the ℌ∞ performance is also guaranteed on the overlapped subregion. Numerical examples are used to demonstrate the effectiveness of this method to reduce the computational load in each design iteration and improved ℌ∞ performance over the conventional simultaneous design method with well-tuned interpolation coefficient.
Coupled multielectrode array sensors made of carbon steel and stainless steels were evaluated and compared with electrochemical noise (EN) sensors. Good correlations between sensor signals and solution corrosivity were observed for all multielectrode array sensors. Some correlation between the average pit index and solution corrosivity was observed for the carbon steel EN sensors, but not for the stainless steel EN sensors. The time-average noise resistances from the stainless steel EN sensors correlate well with solution corrosivity. There were, however, large random fluctuations and drifting for all EN signals, which make the EN sensors unreliable as real-time monitors. 相似文献
Recently, periodic pattern mining from time series data has been studied extensively. However, an interesting type of periodic
pattern, called partial periodic (PP) correlation in this paper, has not been investigated. An example of PP correlation is
that power consumption is high either on Monday or Tuesday but not on both days. In general, a PP correlation is a set of
offsets within a particular period such that the data at these offsets are correlated with a certain user-desired strength.
In the above example, the period is a week (7 days), and each day of the week is an offset of the period. PP correlations
can provide insightful knowledge about the time series and can be used for predicting future values. This paper introduces
an algorithm to mine time series for PP correlations based on the principal component analysis (PCA) method. Specifically,
given a period, the algorithm maps the time series data to data points in a multidimensional space, where the dimensions correspond
to the offsets within the period. A PP correlation is then equivalent to correlation of data when projected to a subset of
the dimensions. The algorithm discovers, with one sequential scan of data, all those PP correlations (called minimum PP correlations)
that are not unions of some other PP correlations. Experiments using both real and synthetic data sets show that the PCA-based
algorithm is highly efficient and effective in finding the minimum PP correlations.
Zhen He is a lecturer in the Department of Computer Science at La Trobe University. His main research areas are database systems
optimization, time series mining, wireless sensor networks, and XML information retrieval. Prior to joining La Trobe University,
he worked as a postdoctoral research associate in the University of Vermont. He holds Bachelors, Honors and Ph.D degrees in
Computer Science from the Australian National University.
X. Sean Wang received his Ph.D degree in Computer Science from the University of Southern California in 1992. He is currently the Dorothean
Chair Professor in Computer Science at the University of Vermont. He has published widely in the general area of databases
and information security, and was a recipient of the US National Science Foundation Research Initiation and CAREER awards.
His research interests include database systems, information security, data mining, and sensor data processing.
Byung Suk Lee is associate professor of Computer Science at the University of Vermont. His main research areas are database systems, data
modeling, and information retrieval. He held positions in industry and academia: Gold Star Electric, Bell Communications Research,
Datacom Global Communications, University of St. Thomas, and currently University of Vermont. He was also a visiting professor
at Dartmouth College and a participating guest at Lawrence Livermore National Laboratory. He served on international conferences
as a program committee member, a publicity chair, and a special session organizer, and also on US federal funding proposal
review panel. He holds a BS degree from Seoul National University, MS from Korea Advanced Institute of Science and Technology,
and Ph.D from Stanford University.
Alan C. H. Ling is an assistant professor at Department of Computer Science in University of Vermont. His research interests include combinatorial
design theory, coding theory, sequence designs, and applications of design theory. 相似文献
The technological revolution of long-awaited energy-saving and vision-friendly displays represented by bistable display technology is conning.Here we discuss methods,challenges,and opportunities for implementing bistable displays in terms of molecular design,device structure,further expansion,and required criteria,hopefully benefiting the light-related community. 相似文献
Use of a copula for generating a sequence of correlated speckle patterns is introduced. The chief characteristic of this algorithm is that it generates a continuous speckle sequence with a specified evolution of the correlation and does so with just two arrays of random numbers. Thus, physically realistic temporally varying speckle patterns with proper first- and second-order statistics are easily realized. We illustrate use of the algorithm for generating sequences with prescribed Gaussian, exponential, and equal-interval correlations and demonstrate how correlation times can be specified independently. This approach to generating sequences of random realizations with prescribed correlations should prove useful in modeling such phenomena as dynamic light scatter, flow-dependent laser speckle contrast, and propagation of spatial coherence. 相似文献
Ink‐free printing based on rewritable paper is an efficient and environmental friendly way to reuse paper, protect resources, and save energy for sustainable development of human society. Among various kinds of rewritable media, light responsive rewritable paper (LRP) is one of the most popular research areas due to its clean and favorable noncontact writing. Visible light is more suitable for LRP for its superior penetration and much less damages to organic molecules than UV light. However, visible‐light‐responsive rewritable paper (VLRP) has only limited successes so far. Herein, a VLRP is newly designed and fabricated based on photoinduced proton transfer (PPT) between photoacid and pH‐sensitive dyes. Success of it is highly benefited from systematical investigation and in‐depth understanding on the key influence factors, such as concentration‐induced undesired isomerization, temperature, humidity, and light intensity, on the PPT and its inverse process. As‐prepared VLRP shows long‐awaited properties, such as, high color contrast and resolution, appropriate legible time of prints, excellent reversibility (>100 cycles), easiness to achieve multicolor prints, and agreeing well with environmental concept of green printing. In addition, study of influence factors on PPT in this work, to some extent, may also help people understand complex photocycle process in biosystem. 相似文献