scholarly journals Nonequilibrium correlations in minimal dynamical models of polymer copying

2019 ◽  
Vol 116 (6) ◽  
pp. 1946-1951 ◽  
Author(s):  
Jenny M. Poulton ◽  
Pieter Rein ten Wolde ◽  
Thomas E. Ouldridge
Keyword(s):  
Living Systems ◽  
Thermodynamic Efficiency ◽  
Dynamical Models ◽  
General Measure ◽  
Chemical Work ◽  
Copy Sequence ◽  
Work Input ◽  
Nonequilibrium States ◽  
Nonequilibrium Correlations ◽  
Insight Into

Living systems produce “persistent” copies of information-carrying polymers, in which template and copy sequences remain correlated after physically decoupling. We identify a general measure of the thermodynamic efficiency with which these nonequilibrium states are created and analyze the accuracy and efficiency of a family of dynamical models that produce persistent copies. For the weakest chemical driving, when polymer growth occurs in equilibrium, both the copy accuracy and, more surprisingly, the efficiency vanish. At higher driving strengths, accuracy and efficiency both increase, with efficiency showing one or more peaks at moderate driving. Correlations generated within the copy sequence, as well as between template and copy, store additional free energy in the copied polymer and limit the single-site accuracy for a given chemical work input. Our results provide insight into the design of natural self-replicating systems and can aid the design of synthetic replicators.

Unravelling Nature's networks

2003 ◽  
Vol 31 (6) ◽  
pp. 1457-1461 ◽  
Author(s):  
N.A.M. Monk
Keyword(s):  
Dynamical System ◽  
Mathematical Modelling ◽  
Computational Analysis ◽  
Spatiotemporal Dynamics ◽  
Interaction Networks ◽  
Living Systems ◽  
Cellular Interaction ◽  
Cellular Mechanisms ◽  
Complex Dynamical System ◽  
Insight Into

Dramatic progress has been made recently in determining the genetic and molecular composition of cells. This has prompted the development of new approaches to the challenge of understanding how basic cellular mechanisms are coordinated to produce the dazzling complexity of living systems. To face this challenge fully, it is critical not only to know what genes and proteins are expressed in cells, but also to understand the spatiotemporal dynamics of their networks of interactions. The sheer scale and complexity of cellular interaction networks necessitates a multi-disciplinary effort in which sophisticated experimental techniques are employed in combination with computational analysis and mathematical modelling. Such approaches are beginning to provide insight into basic structures and mechanisms, and promise to become critical to the post-genomic mission of understanding the cell as a complex dynamical system.

Structural Efficiency Measures for Sections Under Asymmetric Bending

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Neil Buckney ◽  
Alberto Pirrera ◽  
Paul M. Weaver
Keyword(s):  
Structural Response ◽  
General Measure ◽  
Shape Factors ◽  
Structural Efficiency ◽  
Efficiency Measures ◽  
Material Usage ◽  
Beam Section ◽  
Asymmetric Bending ◽  
Insight Into ◽  
Bending Response

Shape factors evaluate the efficiency of material usage in a structure. Previously, they have been developed for simple bending but, in practice, beams often have a more complicated bending response. Therefore, shape factors that account for asymmetric bending are introduced. The shape factors are applied to six example beam sections to demonstrate the effect of shape and load on structural efficiency. The shape factors are also enhanced for inclusion in a more general measure of structural efficiency, the performance index, comprising elements of both geometry and material. Next, a study is performed to show how the asymmetry of a beam section affects structural efficiency. The shape factors can quantitatively evaluate the structural efficiency of beam sections, demonstrating the effect of asymmetric bending on the structural response. Therefore, these shape factors can be used for concept selection and to provide insight into optimal structural design.

scholarly journals Acoustic and inertial modes in planetary-like rotating ellipsoids

2020 ◽  
Vol 476 (2239) ◽  
pp. 20200131
Author(s):  
Jérémie Vidal ◽  
David Cébron
Keyword(s):  
Finite Element ◽  
Liquid Core ◽  
Normal Modes ◽  
Flow Dynamics ◽  
Rotating Fluid ◽  
Rotating Fluids ◽  
Dynamical Models ◽  
Planetary Interiors ◽  
Physical Insight ◽  
Insight Into

The bounded oscillations of rotating fluid-filled ellipsoids can provide physical insight into the flow dynamics of deformed planetary interiors. The inertial modes, sustained by the Coriolis force, are ubiquitous in rapidly rotating fluids and Vantieghem (2014, Proc. R. Soc. A , 470 , 20140093. doi:10.1098/rspa.2014.0093 ) pioneered a method to compute them in incompressible fluid ellipsoids. Yet, taking density (and pressure) variations into account is required for accurate planetary applications, which has hitherto been largely overlooked in ellipsoidal models. To go beyond the incompressible theory, we present a Galerkin method in rigid coreless ellipsoids, based on a global polynomial description. We apply the method to investigate the normal modes of fully compressible, rotating and diffusionless fluids. We consider an idealized model, which fairly reproduces the density variations in the Earth’s liquid core and Jupiter-like gaseous planets. We successfully benchmark the results against standard finite-element computations. Notably, we find that the quasi-geostrophic inertial modes can be significantly modified by compressibility, even in moderately compressible interiors. Finally, we discuss the use of the normal modes to build reduced dynamical models of planetary flows.

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into ◽  
Cis Isomer

Abstract Thermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible-light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days.

scholarly journals Experimental evaluation of thermodynamic cost and speed limit in living cells via information geometry

2020 ◽  
Author(s):  
Sosuke Ito ◽  
Keita Ashida ◽  
Kazuhiro Aoki
Keyword(s):  
Information Processing ◽  
Chemical Reactions ◽  
Information Geometry ◽  
Living Cells ◽  
Living Systems ◽  
Thermodynamic Efficiency ◽  
Uncertainty Relations ◽  
Speed Limit ◽  
Imaging Data ◽  
Stochastic Thermodynamics

Abstract Chemical reactions are responsible for information processing in living cells, and their accuracy and speed have been discussed from a thermodynamic viewpoint. The recent development in stochastic thermodynamics enables evaluating the thermodynamic cost of information processing. However, because experimental estimation of the thermodynamic cost based on stochastic thermodynamics requires a sufficient number of samples, it is only estimated in simple living systems, such as RNA folding and F1-ATPase. Therefore, it is challenging to estimate the thermodynamic cost of information processing by chemical reactions in living cells. Here, we evaluated the thermodynamic cost and its efficiency of information processing in living systems at the single-cell level for the first time by establishing an information-geometric method to estimate them with a relatively small number of samples. We evaluated the thermodynamic cost of the extracellular signal-regulated kinase (ERK) phosphorylation from the time series of the fluorescence imaging data by calculating the intrinsic speed in information geometry. We also evaluated a thermodynamic efficiency based on the thermodynamic speed limit, and thus this paper reports the first experimental test of thermodynamic uncertainty relations in living systems. Our evaluation revealed the change of the efficiency under the conditions of different cell densities and its robustness to the upstream pathway perturbation. Because our approach is widely applicable to other signal transduction pathways, such as the G-protein coupled receptor pathways for sensation, it would clarify efficient mechanisms of information processing in such a living system.

scholarly journals Thermodynamic efficiency evaluation of a low pressure turbo expander cryogenic cycle based on exergy analysis

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 2097-2106
Author(s):  
Chowdhury Roy ◽  
Nathuram Chakraborty ◽  
Swapan Sarkar
Keyword(s):  
Exergy Analysis ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Thermodynamic Efficiency ◽  
Specific Work ◽  
Work Requirement ◽  
Turbo Expander ◽  
The Individual ◽  
Insight Into

Thermodynamic analysis, using the exergy or entropy methods, is usually carried out for better insight into the physical meaning of the losses encountered in a cryogenic plant. From the results of such analysis, it is possible to evaluate the individual efficiencies of the various processes and to identify those calling for an improvement. It is also possible to determine thermodynamic efficiency of the cycle as a whole. The technique involves determination of entropy changes or exergetic losses in each of the processes making up the cycle. Based on the exergy analysis, it has been possible to evaluate specific work requirement, overall thermodynamic efficiency, Specific cooling capacity, work requirement per kg of liquid nitrogen product and coefficient of performance of the turbo expander cryogenic cycle using hydrogen and helium as the refrigerant.

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into

AbstractThermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days. Graphical abstract

Spiral Management

2020 ◽  
pp. 174-199 ◽  
Author(s):  
Justína Mikulášková ◽  
Miloš Čambál ◽  
Ľuboš Polakovič ◽  
Petra Urbanovičová
Keyword(s):  
Human Resources ◽  
Theoretical Basis ◽  
Human Resources Management ◽  
Living Systems ◽  
Economic Losses ◽  
Behavior Patterns ◽  
Strategic Decisions ◽  
Organization Management ◽  
Insight Into

Spiral management and its principles are based on the long-term successful existence of living systems. The principles can be applied to the enterprise and organization management. Living systems manage long-term success by acquiring energy from their surroundings (through nutrition), while enterprises acquire customers and employees' energy in order to eliminate entropy (in enterprises manifested as economic losses). Spiral management is based on the synergy of living systems. It describes behavior patterns in the cyclical development of enterprises as well as the ability of the latter to diagnose their own strategic decisions, including the instructions of how to drive an enterprise towards a long-term success. The chapter describes theoretical basis of spiral management while providing a novel insight into this unique managerial approach and emphasizing its importance for the human resources management. Also introduced are the elements of spiral management applied in the enterprises that want to be competitive and survive turbulent periods.

Sign in / Sign up

Export Citation Format

Share Document