10,873 research outputs found

    Combined first-principles calculation and neural-network correction approach for heat of formation

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    A promising new approach to improve the results of first-principles quantum mechanical calculations and to calibrate their uncertainties is presented. The approach is highly efficient compared to much more sophisticated first-principles methods of similar accuracy, and more importantly, is expected to be applied to much larger systems.published_or_final_versio

    Effect of a current blocking barrier on a 2–6 μm p-GaAs/AlGaAs heterojunction infrared detector

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    We report the performance of a 30 period p-GaAs/AlxGa1 − xAs heterojunction photovoltaic infrared detector, with graded barriers, operating in the 2–6 μm wavelength range. Implementation of a current blocking barrier increases the specific detectivity (D*) under dark conditions by two orders of magnitude to ∼1.9 × 1011 Jones at 2.7 μm, at 77 K. Furthermore, at zero bias, the resistance-area product (R 0 A) attains a value of ∼7.2 × 108 Ω cm2, a five orders enhancement due to the current blocking barrier, with the responsivity reduced by only a factor of ∼1.5

    Microcystin-leucine arginine causes cytotoxic effects in sertoli cells resulting in reproductive dysfunction in male mice

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    2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaVersion of RecordPublishe

    An invisibility cloak using silver nanowires

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    In this paper, we use the parameter retrieval method together with an analytical effective medium approach to design a well-performed invisible cloak, which is based on an empirical revised version of the reduced cloak. The designed cloak can be implemented by silver nanowires with elliptical cross-sections embedded in a polymethyl methacrylate host. This cloak is numerically proved to be robust for both the inner hidden object as well as incoming detecting waves, and is much simpler thus easier to manufacture when compared with the earlier proposed one [Nat. Photon. 1, 224 (2007)].Comment: 7 pages, 4 figures, 2 table

    Ambulatory intraocular pressure fluctuation recording with a novel wireless smart silicone contact lens sensor

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    The Conference program's website is located at http://apacrs2014.org/free_papers.htmlSession - FP1: General: no. FP1-03INTRODUCTION: Monitoring of treatment response in the management of glaucomatous optic neuropathy relies on single intraocular pressure (IOP) measurements during regular clinic hours at regular intervals. However IOP is a dynamic parameter with circadian rhythms as well as posture and exercise related fluctuations. The introduction of continuous 24 hour IOP monitoring technology has created a paradigm shift in glaucoma management. Our wireless smart contact lens sensor was previously validated in-vivo and ex-vivo in animal models. Here we describe the performance of the sensor in ...postprin

    Europeana: What Users Search For and Why

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    People use digital cultural heritage sites in different ways and for various purposes. In this paper we explore what information people search for and why when using Europeana, one of the world’s largest aggregators of cultural heritage. We gathered a probability sample of 240 search requests from users via an online survey and used qualitative content analysis complemented with Shatford-Panofsky’s mode/facet analysis for analysing requests to visual archives to investigate the following: (i) the broad type of search task; (ii) the subject content of searches; and (iii) motives for searching and uses of the information found. Results highlight the rich diversity of searches conducted using Europeana. Contributions include: collection and analysis of a comprehensive sample of Europeana search requests, a scheme for categorising information use, and deeper insights into the users and uses of Europeana

    Prioritized Sweeping Neural DynaQ with Multiple Predecessors, and Hippocampal Replays

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    During sleep and awake rest, the hippocampus replays sequences of place cells that have been activated during prior experiences. These have been interpreted as a memory consolidation process, but recent results suggest a possible interpretation in terms of reinforcement learning. The Dyna reinforcement learning algorithms use off-line replays to improve learning. Under limited replay budget, a prioritized sweeping approach, which requires a model of the transitions to the predecessors, can be used to improve performance. We investigate whether such algorithms can explain the experimentally observed replays. We propose a neural network version of prioritized sweeping Q-learning, for which we developed a growing multiple expert algorithm, able to cope with multiple predecessors. The resulting architecture is able to improve the learning of simulated agents confronted to a navigation task. We predict that, in animals, learning the world model should occur during rest periods, and that the corresponding replays should be shuffled.Comment: Living Machines 2018 (Paris, France

    Polymorphisms of CR1, CLU and PICALM confer susceptibility of Alzheimer's disease in a southern Chinese population

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    In this case-controlled study, we tested susceptible genetic variants for Alzheimer's disease (AD) in CR1, CLU and PICALM from genome-wide association studies (GWAS) in a southern Chinese population. Eight hundred twelve participants consisting of 462 late-onset Alzheimer's disease (LOAD) patients and 350 nondemented control subjects were recruited. We found by multivariate logistic regression analysis, that single nucleotide polymorphisms (SNPs) in CR1 (rs6656401 adjusted allelic p = 0.035; adjusted genotypic p = 0.043) and CLU (rs2279590 adjusted allelic p = 0.035; adjusted genotypic p = 0.006; rs11136000 adjusted allelic p = 0.038; adjusted genotypic p = 0.009) were significantly different between LOAD patients and nondemented controls. For PICALM, LOAD association was found only in the APOE ε4 (-) subgroup (rs3851179 adjusted allelic p = 0.028; adjusted genotypic p = 0.013). Our findings showed evidence of CR1, CLU, and PICALM and LOAD susceptibility in an independent southern Chinese population, which provides additional evidence for LOAD association apart from prior genome-wide association studies in Caucasian populations. © 2012 Elsevier Inc.postprin

    A computational cognition model of perception, memory, and judgment

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    The mechanism of human cognition and its computability provide an important theoretical foundation to intelligent computation of visual media. This paper focuses on the intelligent processing of massive data of visual media and its corresponding processes of perception, memory, and judgment in cognition. In particular, both the human cognitive mechanism and cognitive computability of visual media are investigated in this paper at the following three levels: neurophysiology, cognitive psychology, and computational modeling. A computational cognition model of Perception, Memory, and Judgment (PMJ model for short) is proposed, which consists of three stages and three pathways by integrating the cognitive mechanism and computability aspects in a unified framework. Finally, this paper illustrates the applications of the proposed PMJ model in five visual media research areas. As demonstrated by these applications, the PMJ model sheds some light on the intelligent processing of visual media, and it would be innovative for researchers to apply human cognitive mechanism to computer science.</p

    Unique walnut-shaped porous MnO<inf>2</inf>/C nanospheres with enhanced reaction kinetics for lithium storage with high capacity and superior rate capability

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    Unique walnut-shaped porous MnO2/carbon nanospheres via in situ carbonization of amorphous MnO2 nanospheres demonstrate enhanced reaction kinetics for lithium storage.This work is realized in the frame of a program for Changjiang Scholars and Innovative Research Team (IRT_15R52) of Chinese Ministry of Education. B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Life Membership at the Clare Hall, Cambridge and the financial support of the Department of Chemistry, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. T. Hasan acknowledges funding from the Royal Academy of Engineering (Graphlex) and an Impact Acceleration Award (GRASS). This work is also financially supported by the National Science Foundation for Young Scholars of China (No. 21301133 and 51302204), International Science & Technology Cooperation Program of China (2015DFE52870) and and Self-determined and Innovative Research Funds of the SKLWUT (2015‐ZD‐7). The authors also would like to thank Dr. Bin-Jie Wang from Shanghai Nanoport (FEI, Shanghai) for TEM analysis, and thank Hang Ping from Wuhan University of Technology for the TGA/DSC tests.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C6TA00594
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