Wide optical force-induced RF dynamic range and 100+ high-order stable mechanics in chip-scale optomechanical cavities

2016 ◽  
Author(s):  
Yongjun Huang ◽  
Jaime Gonzalo Flor Flores ◽  
Ziqiang Cai ◽  
Mingbin Yu ◽  
Dim-Lee Kwong ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Order ◽  
Optical Force

scholarly journals Asymmetric high-order anatomical brain connectivity sculpts effective connectivity

2020 ◽  
Vol 4 (3) ◽  
pp. 871-890
Author(s):  
Arseny A. Sokolov ◽  
Peter Zeidman ◽  
Adeel Razi ◽  
Michael Erb ◽  
Philippe Ryvlin ◽  
...  
Keyword(s):  
White Matter ◽  
Dynamic Range ◽  
Diffusion Processes ◽  
Brain Connectivity ◽  
Effective Connectivity ◽  
Structural Connectivity ◽  
Laplacian Matrix ◽  
Graph Laplacian ◽  
Brain Regions ◽  
High Order

Bridging the gap between symmetric, direct white matter brain connectivity and neural dynamics that are often asymmetric and polysynaptic may offer insights into brain architecture, but this remains an unresolved challenge in neuroscience. Here, we used the graph Laplacian matrix to simulate symmetric and asymmetric high-order diffusion processes akin to particles spreading through white matter pathways. The simulated indirect structural connectivity outperformed direct as well as absent anatomical information in sculpting effective connectivity, a measure of causal and directed brain dynamics. Crucially, an asymmetric diffusion process determined by the sensitivity of the network nodes to their afferents best predicted effective connectivity. The outcome is consistent with brain regions adapting to maintain their sensitivity to inputs within a dynamic range. Asymmetric network communication models offer a promising perspective for understanding the relationship between structural and functional brain connectomes, both in normalcy and neuropsychiatric conditions.

Dynamic range extension technique for high-order ADCs by digital level control

1997 ◽  
Vol 33 (25) ◽  
pp. 2094 ◽  
Author(s):  
Dong-Yun Lee ◽  
Min-Kyu Kim ◽  
Dae-Yun Shim ◽  
Wonchan Kim
Keyword(s):  
Dynamic Range ◽  
High Order ◽  
Range Extension ◽  
Level Control

scholarly journals Supercritical dynamics at the edge-of-chaos underlies optimal decision-making

2021 ◽  
Author(s):  
Adrián Fernández Amil ◽  
Paul F.M.J. Verschure
Keyword(s):  
Phase Transition ◽  
Decision Making ◽  
Dynamic Range ◽  
High Order ◽  
Optimal Decision ◽  
Inhibitory Interneurons ◽  
Persistent Activity ◽  
Perceptual Decision Making ◽  
Edge Of Chaos ◽  
Cortical Hierarchy

Abstract Critical dynamics, characterized by scale-free neuronal avalanches, is thought to underlie optimal function in the sensory cortices by maximizing information transmission, capacity, and dynamic range. In contrast, deviations from criticality have not yet been considered to support any cognitive processes. Nonetheless, neocortical areas related to working memory and decision-making seem to rely on long-lasting periods of ignition-like persistent firing. Such firing patterns are reminiscent of supercritical states where runaway excitation dominates the circuit dynamics. In addition, a macroscopic gradient of the relative density of Somatostatin (SST+) and Parvalbumin (PV+) inhibitory interneurons throughout the cortical hierarchy has been suggested to determine the functional specialization of low- versus high-order cortex. These observations thus raise the question of whether persistent activity in high-order areas results from the intrinsic features of the neocortical circuitry. We used an attractor model of the canonical cortical circuit performing a perceptual decision-making task to address this question. Our model reproduces the known saddle-node bifurcation where persistent activity emerges, merely by increasing the SST+/PV+ ratio while keeping the input and recurrent excitation constant. The regime beyond such a phase transition renders the circuit increasingly sensitive to random fluctuations of the inputs -i.e., chaotic-, defining an optimal SST+/PV+ ratio around the edge-of-chaos. Further, we show that both the optimal SST+/PV+ ratio and the region of the phase transition decrease monotonically with increasing input noise. This suggests that cortical circuits regulate their intrinsic dynamics via inhibitory interneurons to attain optimal sensitivity in the face of varying uncertainty. Hence, on the one hand, we link the emergence of supercritical dynamics at the edge-of-chaos to the gradient of the SST+/PV+ ratio along the cortical hierarchy, and, on the other hand, explain the behavioral effects of the differential regulation of SST+ and PV+ interneurons by neuromodulators like acetylcholine in the presence of input uncertainty.

Dynamic range extension technique for high-order sigma delta ADCS by digital level control

1999 ◽  
Vol 21 (2) ◽  
pp. 98
Author(s):  
Dong-Yun Lee ◽  
Min-Kyu Kim ◽  
Dae-Yun Shim ◽  
Wonchan Kim
Keyword(s):  
Dynamic Range ◽  
High Order ◽  
Range Extension ◽  
Level Control ◽  
Sigma Delta

scholarly journals Cusp-artifacts in high order Superresolution Optical Fluctuation Imaging

2019 ◽  
Author(s):  
Xiyu Yi ◽  
Shimon Weiss
Keyword(s):  
Dynamic Range ◽  
Imaging Techniques ◽  
Photophysical Properties ◽  
Super Resolution ◽  
High Order ◽  
Fluorescence Probes ◽  
Structured Illumination ◽  
Odd Order ◽  
Even Order ◽  
High Order Cumulants

AbstractSuperresolution Optical Fluctuation Imaging (SOFI) offers a simple and affordable alternative to the more sophisticated (and expensive) super-resolution imaging techniques such as STED, PALM, STORM, structured illumination, and other derivative methods. In SOFI, the calculation of high order cumulants provides higher resolution but drastically expands the dynamic range of the resulting image. In this study, we have identified another type of artifact for high order SOFI cumulants, dubbed as ‘cusp artifacts.’ A series of realistic simulations are performed to study the cusp artifacts under the influences of various factors, including the blinking statistics, the spatial distribution of photophysical properties of the sample, the total number of frames processed per dataset, photobleaching, and noise. Experiments, simulations, and theory all show that high order cumulants and odd-order moments could suffer from cusp artifacts. These cusp artifacts also degrade the fidelity of bSOFI that has been proposed to solve the dynamic range expansion of image pixel intensities. Alternatively, cusp-artifacts could be altogether eliminated by utilizing even-order moments constructed directly or from cumulants for image reconstruction. Together with dynamic range compression, these approaches yield improved SOFI images. Our study provides new insight into the nature of high order SOFI images, outlines guidelines for developing and screening SOFI-optimized fluorescence probes, and suggests improved strategies for SOFI data acquisition.

scholarly journals Moments reconstruction and local dynamic range compression of high order superresolution optical fluctuation imaging

2019 ◽  
Vol 10 (5) ◽  
pp. 2430 ◽  
Author(s):  
Xiyu Yi ◽  
Sungho Son ◽  
Ryoko Ando ◽  
Atsushi Miyawaki ◽  
Shimon Weiss
Keyword(s):  
Dynamic Range ◽  
High Order ◽  
Local Dynamic ◽  
Dynamic Range Compression

Dynamic Range Enhancement via Linearized Output in Nanoelectromechanical Systems by Combining High-Order Harmonics

2021 ◽  
pp. 1-1
Author(s):  
Keita Funayama ◽  
Hiroya Tanaka ◽  
Jun Hirotani ◽  
Keiichi Shimaoka ◽  
Yutaka Ohno ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Order ◽  
Nanoelectromechanical Systems

scholarly journals Moments reconstruction and local dynamic range compression of high order Superresolution Optical Fluctuation Imaging

2018 ◽  
Author(s):  
Xiyu Yi ◽  
Sungho Son ◽  
Ryoko Ando ◽  
Atsushi Miyawaki ◽  
Shimon Weiss
Keyword(s):  
Dynamic Range ◽  
Imaging Techniques ◽  
Resolution Enhancement ◽  
Super Resolution ◽  
High Order ◽  
Live Cells ◽  
Local Dynamic ◽  
Actin Stress Fiber ◽  
Dynamic Range Compression ◽  
Even Order

Abstract:Super-resolution Optical Fluctuation Imaging (SOFI) offers a simple and affordable alternative to other super-resolution (SR) imaging techniques. The theoretical resolution enhancement of SOFI scales linearly with the cumulants’ order, while imaging conditions are less phototoxic to living samples as compared to other SR methods. High order SOFI could, therefore, be a method of choice for dynamic live cell imaging. However, due to cusp-artifacts and to dynamic range expansion of pixel intensities, this promise has not been materialized as of yet. Here we investigated and compared high order moments vs. high order cumulants SOFI reconstructions. We demonstrate that even-order moments reconstructions are intrinsically free of cusp artifacts, allowing for a subsequent deconvolution operation to be performed, hence enhancing the resolution even further. High order moments reconstructions performance was examined for various (simulated) conditions and applied to (experimental) imaging of QD labeled microtubules in fixed cells, and actin stress fiber dynamics in live cells.

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