Involvement of the prelimbic cortex in contextual fear conditioning with temporal and spatial discontinuity

2017 ◽  
Vol 144 ◽  
pp. 1-10 ◽  
Author(s):  
Thays Brenner Santos ◽  
Juliana Carlota Kramer-Soares ◽  
Vanessa Manchim Favaro ◽  
Maria Gabriela Menezes Oliveira
Keyword(s):  
Fear Conditioning ◽  
Contextual Fear Conditioning ◽  
Prelimbic Cortex ◽  
Contextual Fear ◽  
Temporal And Spatial ◽  
Spatial Discontinuity

scholarly journals Improvement of Performance, Stability and Continuity by Modified Size-Consistent Multipartitioning Quantum Mechanical/Molecular Mechanical Method

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1882 ◽  
Author(s):  
Hiroshi Watanabe
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Quantum Chemical ◽  
Quantum Mechanical ◽  
Mechanical Method ◽  
Chemical Effects ◽  
Temporal And Spatial ◽  
Dynamics Simulations ◽  
Spatial Discontinuity ◽  
Condensed Systems

For condensed systems, the incorporation of quantum chemical solvent effects into molecular dynamics simulations has been a major concern. To this end, quantum mechanical/molecular mechanical (QM/MM) techniques are popular and powerful options to treat gigantic systems. However, they cannot be directly applied because of temporal and spatial discontinuity problems. To overcome these problems, in a previous study, we proposed a corrective QM/MM method, size-consistent multipartitioning (SCMP) QM/MM and successfully demonstrated that, using SCMP, it is possible to perform stable molecular dynamics simulations by effectively taking into account solvent quantum chemical effects. The SCMP method is characterized by two original features: size-consistency of a QM region among all QM/MM partitioning and partitioning update. However, in our previous study, the performance was not fully elicited compared to the theoretical upper bound and the optimal partitioning update protocol and parameters were not fully verified. To elicit the potential performance, in the present study, we simplified the theoretical framework and modified the partitioning protocol.

scholarly journals Improvement of Performance, Stability, and Continuity by Modified Size-Consistent Multipartitioning QM/MM Method

2018 ◽  
Author(s):  
Hiroshi C. Watanabe
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Quantum Chemical ◽  
Quantum Mechanical ◽  
Size Consistency ◽  
Chemical Effects ◽  
Temporal And Spatial ◽  
Dynamics Simulations ◽  
Spatial Discontinuity ◽  
Condensed Systems

For condensed systems, the incorporation of quantum chemical solvent effects into molecular dynamics simulations has been a major concern. To this end, quantum mechanical/molecular mechanical (QM/MM) techniques are popular and powerful options to treat gigantic systems. However, they cannot be directly applied because of temporal and spatial discontinuity problems. To overcome these problems, in a previous study, we proposed a corrective QM/MM method, size-consistent multipartitioning (SCMP) QM/MM, and successfully demonstrated that, using SCMP, it is possible to perform stable molecular dynamics simulations by effectively taking into account solvent quantum chemical effects. The SCMP method is characterized by two original features: size-consistency of a QM region among all QM/MM partitioning and partitioning update. However, in our previous study, the performance was not fully elicited compared to the theoretical upper bound, and the optimal partitioning update protocol and parameters were not fully verified. To elicit the potential performance, in the present study, we simplified the theoretical framework and modified the partitioning protocol.

Quantitative Analysis and Correction of Quantum Mechanics/Molecular Mechanics Boundary Artifacts in Adaptive QM/MM Methods

2019 ◽  
Author(s):  
Hiroshi Watanabe ◽  
Qiang Cui
Keyword(s):  
Quantum Mechanics ◽  
Quantitative Analysis ◽  
Molecular Mechanics ◽  
Bulk Water ◽  
Dynamics Simulation ◽  
Chemical Effects ◽  
Temporal Continuity ◽  
Temporal And Spatial ◽  
Dynamics Simulations ◽  
Spatial Discontinuity

The incorporation of quantum chemical effects of solvation into molecular dynamics simulation has been a challenging issue due to solvent diffusion. To this end, various adaptive quantum mechanics/molecular mechanics (QM/MM) methods have been proposed, in which free solvent exchanges are allowed via a flexible switching of their identities between QM and MM models according to their distances from the QM solute. However, temporal and spatial discontinuities that remain in the standard implementations continue to hamper stable and accurate dynamics simulations using adaptive QM/MM approaches. We previously demonstrated that the size-consistent multi-partitioning (SCMP) method achieved temporal continuity while avoiding spatial discontinuities to some extent. In the present study, however, we demonstrate that the residual spatial discontinuity may lead to severe problems under certain conditions; via quantitative analysis, we show that not only adaptive QM/MM but also all multiscale approaches might share these problems implicitly, which have not been investigated in depth so far. To alleviate these artifacts, we propose a correction based on the SCMP approach and conduct benchmark simulations using bulk water systems.

Quantitative Analysis of Quantum Mechanics/Molecular Mechanics Boundary Artifacts and the correction in Adaptive QM/MM Methods

2019 ◽  
Author(s):  
Hiroshi Watanabe ◽  
Qiang Cui
Keyword(s):  
Quantum Mechanics ◽  
Quantitative Analysis ◽  
Molecular Mechanics ◽  
Bulk Water ◽  
Dynamics Simulation ◽  
Chemical Effects ◽  
Temporal Continuity ◽  
Temporal And Spatial ◽  
Dynamics Simulations ◽  
Spatial Discontinuity

The incorporation of quantum chemical effects of solvation into molecular dynamics simulation has been a challenging issue due to solvent diffusion. To this end, various adaptive quantum mechanics/molecular mechanics (QM/MM) methods have been proposed, in which free solvent exchanges are allowed via a flexible switching of their identities between QM and MM models according to their distances from the QM solute. However, temporal and spatial discontinuities that remain in the standard implementations continue to hamper stable and accurate dynamics simulations using adaptive QM/MM approaches. We previously demonstrated that the size-consistent multi-partitioning (SCMP) method achieved temporal continuity while avoiding spatial discontinuities to some extent. In the present study, however, we demonstrate that the residual spatial discontinuity may lead to severe problems under certain conditions; via quantitative analysis, we show that not only adaptive QM/MM but also all multiscale approaches might share these problems implicitly, which have not been investigated in depth so far. To alleviate these artifacts, we propose a correction based on the SCMP approach and conduct benchmark simulations using bulk water systems.

scholarly journals ”Aika on kaikkein haurain pinta”

2016 ◽  
pp. 52-66
Author(s):  
Anna Pehkoranta
Keyword(s):  
Emotional Experience ◽  
Historical Context ◽  
Political Regime ◽  
Close Reading ◽  
Tiananmen Square ◽  
Individual Level ◽  
Experience Of Time ◽  
Temporal And Spatial ◽  
The One ◽  
Spatial Discontinuity

“Time Is the Flimsiest Surface.” Affective Distance and the Weight of History in Yiyun Li’s Kinder Than Solitude This article examines the linkages between personal and political history and their relationship to the experience of time and a ective distance in Yiyun Li’s (b. 1972) novel Kinder an Solitude (2014). The method of analysis is a combination of close reading with a specific focus on affective distance, and a historically contextualizing approach. In this article, the notion of affective distance refers to an individual level psychic and emotional experience of estrangement, loneliness, and temporal and spatial discontinuity. The manifestation of a ective distance in Li’s novel is analyzed in relation to Sianne Ngai’s (2005) theory of ambivalent and “noncathartic” feelings that characterize late modernity and are associated with situations of blocked or suspended agency. The article also discusses the historical context of Li’s novel, the Tiananmen Square protests of 1989 and their political aftermath, in light of Michel Foucault’s (1976) and Giorgio Agamben’s (1998) theories of biopower and biopolitics. It concludes that the affective distance experienced by the novel’s three main characters is rooted, on the one hand, in their traumatic personal past, and on the other, in China’s recent history and its political present in the ambivalent space between an authoritarian political regime and neoliberal market economy.

Quantitative Analysis of Quantum Mechanics/Molecular Mechanics Boundary Artifacts and the correction in Adaptive QM/MM Methods

2019 ◽  
Author(s):  
Hiroshi Watanabe ◽  
Qiang Cui
Keyword(s):  
Quantum Mechanics ◽  
Quantitative Analysis ◽  
Molecular Mechanics ◽  
Bulk Water ◽  
Dynamics Simulation ◽  
Chemical Effects ◽  
Temporal Continuity ◽  
Temporal And Spatial ◽  
Dynamics Simulations ◽  
Spatial Discontinuity

The incorporation of quantum chemical effects of solvation into molecular dynamics simulation has been a challenging issue due to solvent diffusion. To this end, various adaptive quantum mechanics/molecular mechanics (QM/MM) methods have been proposed, in which free solvent exchanges are allowed via a flexible switching of their identities between QM and MM models according to their distances from the QM solute. However, temporal and spatial discontinuities that remain in the standard implementations continue to hamper stable and accurate dynamics simulations using adaptive QM/MM approaches. We previously demonstrated that the size-consistent multi-partitioning (SCMP) method achieved temporal continuity while avoiding spatial discontinuities to some extent. In the present study, however, we demonstrate that the residual spatial discontinuity may lead to severe problems under certain conditions; via quantitative analysis, we show that not only adaptive QM/MM but also all multiscale approaches might share these problems implicitly, which have not been investigated in depth so far. To alleviate these artifacts, we propose a correction based on the SCMP approach and conduct benchmark simulations using bulk water systems.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

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