205 research outputs found
Few-molecule reservoir computing experimentally demonstrated with surface enhanced Raman scattering and ion-gating stimulation
Reservoir computing (RC) is a promising solution for achieving low power
consumption neuromorphic computing, although the large volume of the physical
reservoirs reported to date has been a serious drawback in their practical
application. Here, we report the development of a few-molecule RC that employs
the molecular vibration dynamics in the para-mercaptobenzoic acid (pMBA)
detected by surface enhanced Raman scattering (SERS) with tungsten oxide
nanorod/silver nanoparticles (WOx@Ag-NPs). The Raman signals of the pMBA
molecules, adsorbed at the SERS active site of WOx@Ag-NPs, were reversibly
perturbated by the application of voltage-induced local pH changes in the
vicinity of the molecules, and then used to perform RC of pattern recognition
and prediction tasks. In spite of the small number of molecules employed, our
system achieved good performance, including 95.1% to 97.7% accuracy in various
nonlinear waveform transformations and 94.3% accuracy in solving a second-order
nonlinear dynamic equation task. Our work provides a new concept of molecular
computing with practical computation capabilities.Comment: 22 pages, 4 figure
A high-performance deep reservoir computing experimentally demonstrated with ion-gating reservoirs
While physical reservoir computing (PRC) is a promising way to achieve low
power consumption neuromorphic computing, its computational performance is
still insufficient at a practical level. One promising approach to improving
PRC performance is deep reservoir computing (deep-RC), in which the component
reservoirs are multi-layered. However, all of the deep-RC schemes reported so
far have been effective only for simulation reservoirs and limited PRCs, and
there have been no reports of nanodevice implementations. Here, as the first
nanodevice implementation of Deep-RC, we report a demonstration of deep
physical reservoir computing using an ion gating reservoir (IGR), which is a
small and high-performance physical reservoir. While previously reported
Deep-RC scheme did not improve the performance of IGR, our Deep-IGR achieved a
normalized mean squared error of 0.0092 on a second-order nonlinear
autoregressive moving average task, with is the best performance of any
physical reservoir so far reported. More importantly, the device outperformed
full simulation reservoir computing. The dramatic performance improvement of
the IGR with our deep-RC architecture paves the way for high-performance,
large-scale, physical neural network devices.Comment: 21 pages, 6 figure
キゴウ モデル ケンサ ノ ヘイコウ ソフトウェア システム ヘノ オウヨウ
第17回回路とシステム軽井沢ワークショップ論文集The 17th Workshop on Circuits and Systems in Karuizawa. April 26. 27. 200
Minimizing the maximum delay for reaching consensus in quorum-based mutual exclusion schemes
Prevention of pin tract infection with titanium-copper alloys
金沢大学医薬保健研究域医学系The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial. © 2009 Wiley Periodicals, Inc
The cyanobacterium Gloeobacter violaceus PCC 7421 uses bacterial-type phytoene desaturase in carotenoid biosynthesis
AbstractCarotenoid composition and its biosynthetic pathway in the cyanobacterium Gloeobacter violaceus PCC 7421 were investigated. β-Carotene and (2S,2′S)-oscillol 2,2′-di(α-l-fucoside), and echinenone were major and minor carotenoids, respectively. We identified two unique genes for carotenoid biosynthesis using in vivo functional complementation experiments. In Gloeobacter, a bacterial-type phytoene desaturase (CrtI), rather than plant-type desaturases (CrtP and CrtQ), produced lycopene. This is the first demonstration of an oxygenic photosynthetic organism utilizing bacterial-type phytoene desaturase. We also revealed that echinenone synthesis is catalyzed by CrtW rather than CrtO. These findings indicated that Gloeobacter retains ancestral properties of carotenoid biosynthesis
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