scholarly journals Rare events via multiple reaction channels sampled by path replica exchange

2008 ◽  
Vol 129 (11) ◽  
pp. 114108 ◽  
Author(s):  
Peter G. Bolhuis
2020 ◽  
Vol 39 (6) ◽  
pp. 8463-8475
Author(s):  
Palanivel Srinivasan ◽  
Manivannan Doraipandian

Rare event detections are performed using spatial domain and frequency domain-based procedures. Omnipresent surveillance camera footages are increasing exponentially due course the time. Monitoring all the events manually is an insignificant and more time-consuming process. Therefore, an automated rare event detection contrivance is required to make this process manageable. In this work, a Context-Free Grammar (CFG) is developed for detecting rare events from a video stream and Artificial Neural Network (ANN) is used to train CFG. A set of dedicated algorithms are used to perform frame split process, edge detection, background subtraction and convert the processed data into CFG. The developed CFG is converted into nodes and edges to form a graph. The graph is given to the input layer of an ANN to classify normal and rare event classes. Graph derived from CFG using input video stream is used to train ANN Further the performance of developed Artificial Neural Network Based Context-Free Grammar – Rare Event Detection (ACFG-RED) is compared with other existing techniques and performance metrics such as accuracy, precision, sensitivity, recall, average processing time and average processing power are used for performance estimation and analyzed. Better performance metrics values have been observed for the ANN-CFG model compared with other techniques. The developed model will provide a better solution in detecting rare events using video streams.


2018 ◽  
Vol 28 (3) ◽  
pp. 265 ◽  
Author(s):  
Son Tung Ngo

The Amyloid beta (Aβ) oligomers are characterized as critical cytotoxic materials in Alzheimer’s disease (AD) pathogenesis. Structural details of transmembrane oligomers are inevitably necessary to design/search potential inhibitor due to treat AD. However, the experimental detections for structural modify of low-order Aβ oligomers are precluded due to the extremely dynamic fluctuation of the oligomers. In this project, the transmembrane Italian-mutant (E22K) 3Aβ11-40 (tmE22K 3Aβ11-40) was extensively investigated upon the temperature replica exchange molecular dynamics (REMD) simulations. The structural changes of the trimer when replacing the negative charged residue E22 by a positively charged residue K were monitored over simulation intervals. The oligomer size was turned to be larger and the increase of β-content was recorded. The momentous gain of intermolecular contacts with DPPC molecules implies that tmE22K 3Aβ11-40 easier self-inserts into the membrane than the WT one. Furthermore, the tighter interaction between constituting monomers was indicated implying that the E22K mutation probably enhances the Aβ fibril formation. The results are in good agreement with experiments that E22K amyloid is self-aggregate faster than the WT form. Details information of tmE22K trimer structure and kinetics probably yield the understanding of AD mechanism.


1979 ◽  
Vol 34 (3) ◽  
pp. 495-501 ◽  
Author(s):  
C. Wesdemiotis ◽  
H. Schwarz ◽  
C. C. Van de Sande ◽  
F. Van Gaever

Abstract The investigation of several 13carbon and deuterium labelled n-butyl and n-pentyl benzenes demonstrate that chemical ionization (reagent gas: methane) induces specific carbon-carbon bond cleavages of the alkyl group. The extent of competing reaction channels as for instance direct alkene elimination versus dealkylation/reprotonation is analyzed. Partial hydrogen exchange processes between reagent ions and substrate molecules are restricted to the phenyl ring. Intramolecular exchange reactions between the side chain and the aromatic ring which are typical for the open shell molecular ions of alkyl benzenes are not observed for analogous closed shell cations.


2021 ◽  
Vol 263 ◽  
pp. 107911
Author(s):  
Chudong Xu ◽  
Shengdong Lu ◽  
Yongfeng Kong ◽  
Wanjie Xiong

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