scholarly journals Extracting Work Optimally with Imprecise Measurements

Entropy ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 8
Author(s):  
Luis Dinis ◽  
Juan Manuel Rodríguez Parrondo
Keyword(s):  
Feedback Loop ◽  
Brownian Particle ◽  
Close Relation ◽  
Optical Tweezer ◽  
Maximum Amount ◽  
Thermal Bath ◽  
Single Measurement ◽  
Stochastic Thermodynamics ◽  
External Agent ◽  
High Degree

Measurement and feedback allows for an external agent to extract work from a system in contact with a single thermal bath. The maximum amount of work that can be extracted in a single measurement and the corresponding feedback loop is given by the information that is acquired via the measurement, a result that manifests the close relation between information theory and stochastic thermodynamics. In this paper, we show how to reversibly confine a Brownian particle in an optical tweezer potential and then extract the corresponding increase of the free energy as work. By repeatedly tracking the position of the particle and modifying the potential accordingly, we can extract work optimally, even with a high degree of inaccuracy in the measurements.

scholarly journals Thermal Fluctuations in Electric Circuits and the Brownian Motion

2010 ◽  
Vol 61 (4) ◽  
pp. 252-256 ◽  
Author(s):  
Gabriela Vasziová ◽  
Jana Tóthová ◽  
Lukáš Glod ◽  
Vladimír Lisý
Keyword(s):  
Brownian Motion ◽  
Brownian Particle ◽  
Mean Square Displacement ◽  
Thermal Fluctuations ◽  
Stochastic Equations ◽  
Thermal Bath ◽  
Current Fluctuations ◽  
Electric Circuits ◽  
The Mean ◽  
Optically Trapped

Thermal Fluctuations in Electric Circuits and the Brownian MotionIn this work we explore the mathematical correspondence between the Langevin equation that describes the motion of a Brownian particle (BP) and the equations for the time evolution of the charge in electric circuits, which are in contact with the thermal bath. The mean quadrate of the fluctuating electric charge in simple circuits and the mean square displacement of the optically trapped BP are governed by the same equations. We solve these equations using an efficient approach that allows us converting the stochastic equations to ordinary differential equations. From the obtained solutions the autocorrelation function of the current and the spectral density of the current fluctuations are found. As distinct from previous works, the inertial and memory effects are taken into account.

scholarly journals The WT1-like transcription factor Klumpfuss maintains lineage commitment in the intestine

2019 ◽  
Author(s):  
Jerome Korzelius ◽  
Tal Ronnen-Oron ◽  
Maik Baldauf ◽  
Elke Meier ◽  
Pedro Sousa-Victor ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Feedback Loop ◽  
Common Mechanism ◽  
Cell Fates ◽  
Daughter Cells ◽  
Transient Activation ◽  
Transient Activity ◽  
Temporal Restriction ◽  
High Degree

AbstractStem cell (SC) lineages in barrier epithelia exhibit a high degree of plasticity. Mechanisms that govern the precise specification of SC daughter cells during regenerative episodes are therefore critical to maintain homeostasis. One such common mechanism is the transient activation of the Notch (N) signaling pathway. N controls the choice between absorptive and entero-endocrine cell fates in both the mammalian small intestine and theDrosophilamidgut, yet how precisely N signaling promotes lineage restriction in progenitor cells remains unclear. Here, we describe a role for the WT1-like transcription factor Klumpfuss (Klu) in restricting the fate ofDrosophilaenteroblasts (EBs) downstream of N activation. Klu is transiently induced in Notch-positive EBs and its transient activity restricts cell fate towards the enterocyte (EC) lineage. Transcriptomics and DamID profiling show that Klu suppresses enteroendocrine (EE) cell fates by repressing E(Spl)m8-HLH and Phyllopod, both negative regulators of the proneural gene Scute, which is essential for EE differentiation. At the same time, Klu suppresses cell cycle genes, committing EBs to differentiation. Klu-mediated repression of its own transcription further sets up a negative feedback loop that ensures temporal restriction of Klu-mediated gene regulation, and is essential for subsequent differentiation of ECs. Our findings define a transient cell state in which EC lineage restriction is cemented, and establish a hierarchy of transcriptional programs critical in executing a differentiation program downstream of initial induction events governed by N signaling.

scholarly journals Equilibrium Stochastic Delay Processes

2022 ◽  
Author(s):  
Viktor Holubec ◽  
Artem Ryabov ◽  
Sarah A. M. Loos ◽  
Klaus Kroy
Keyword(s):  
Linear Models ◽  
Linear Time ◽  
Brownian Particle ◽  
Signal Transmission ◽  
Point Of View ◽  
Thermal Bath ◽  
Temporal Delay ◽  
Science And Engineering ◽  
Stochastic Delay ◽  
Starting Point

Abstract Stochastic processes with temporal delay play an important role in science and engineering whenever finite speeds of signal transmission and processing occur. However, an exact mathematical analysis of their dynamics and thermodynamics is available for linear models only. We introduce a class of stochastic delay processes with nonlinear time-local forces and linear time-delayed forces that obey fluctuation theorems and converge to a Boltzmann equilibrium at long times. From the point of view of control theory, such ``equilibrium stochastic delay processes'' are stable and energetically passive, by construction. Computationally, they provide diverse exact constraints on general nonlinear stochastic delay problems and can, in various situations, serve as a starting point for their perturbative analysis. Physically, they admit an interpretation in terms of an underdamped Brownian particle that is either subjected to a time-local force in a non-Markovian thermal bath or to a delayed feedback force in a Markovian thermal bath. We illustrate these properties numerically for a setup familiar from feedback cooling and point out experimental implications.

scholarly journals Thermalization of a Trapped Single Atom with an Atomic Thermal Bath

2021 ◽  
Vol 11 (5) ◽  
pp. 2258
Author(s):  
Rahul Sawant ◽  
Anna Maffei ◽  
Giovanni Barontini
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Thermal Equilibrium ◽  
Ultracold Atoms ◽  
Optical Tweezer ◽  
Single Atom ◽  
Thermal Bath ◽  
Vibrational States

We studied a single atom trapped in an optical tweezer interacting with a thermal bath of ultracold atoms of a different species. Because of the collisions between the trapped atom and the bath atoms, the trapped atom undergoes changes in its vibrational states occupation to reach thermal equilibrium with the bath. By using Monte Carlo simulations, we characterized the single atom’s thermalization process, and we studied how this can be used for cooling. Our simulations demonstrate that, within known experimental limitations, it is feasible to cool a trapped single atom with a thermal bath.

scholarly journals Influence of weather factors on separate periods of fungus Claviceps purpurea (Fr.) Tul development and level of ergot harmfulness in Kirov region

2019 ◽  
Vol 20 (2) ◽  
pp. 134-143 ◽  
Author(s):  
L. M. Shchekleina
Keyword(s):  
Close Relation ◽  
Artificial Inoculation ◽  
Winter Rye ◽  
Regression Equations ◽  
Claviceps Purpurea ◽  
Weather Factors ◽  
Positive Dependence ◽  
Qualitative Trait ◽  
High Productivity ◽  
High Degree

In 2001-2017 in the conditions of Kirov region 36 winter rye varieties were assessed according to the character of interrelation in a "Secale cereale - Claviceps purpurea" pathosystem. The article provides the results of this research. For assessment of the change in meteorological conditions and their influence on ergot development the average daily air temperature and amount of precipitations from May 1 to May 31 (the period of screrotia germination) and from June 5 to June 15 (the period of plants infection) were used. The study of varieties was carried out by artificial inoculation of flowers with pathogen suspension. The ergot recording was carried out at a phase of milk-wax ripeness of grain according to infection of biocenoses (quantitative trait) and on contamination of grain mass with sclerotia (qualitative trait). At an artificial inoculation all rye varieties under study were infected by ergot in limits from 8.3 up to 100% that demonstrated their strong susceptibility to disease. Only 6 varieties (Falenskaya 4, Kirovskaya 89, Rada, Flora, Dymka, and Volkhova) were infected at the level of 8.3-27.3%, contamination of grain mass by sclerotia – 0.4-1.9%. The standard variety Falenskaya 4 had a high productivity and efficiency of plants (660 g/m2 and 11.0 g), which was characterized by a high degree of re-growth after infestation with a snow mold (100%), the smallest distribution of an ergot in sowing and contamination of grain mass with sclerotia. During the correlation analysis a close relation between the infestation of plants with an ergot and contamination of grain mass with sclerotia (r = 0.76) was established. The same immunological traits significantly influenced on the productivity (r = -0.67 and -0.55) and insignificantly - on plants efficiency. The positive dependence between immunological traits and 1000-grain mass was revealed. Possibly, sterilization of an ear leads to formation of a larger grain in fertile flowers (r = 0.42 and 0.37). The regression equations between the amount of sclerotia in an ear, mass of grain per ear and a number of grains in it have proved with 95-97% probability that with 1 sclerotium increase in contamination per ear, the grain mass per ear decreases by 0.18 grams, and the amount of grains per ear – by 4.7 pieces.

scholarly journals Out of time ordered effective dynamics of a quartic oscillator

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Bidisha Chakrabarty ◽  
Soumyadeep Chaudhuri
Keyword(s):  
Effective Action ◽  
Thermal Noise ◽  
Stochastic Dynamics ◽  
Brownian Particle ◽  
Effective Theory ◽  
Thermal Bath ◽  
Effective Dynamics ◽  
Fluctuation Dissipation ◽  
Weakly Coupled ◽  
Non Linear

We study the dynamics of a quantum Brownian particle weakly coupled to a thermal bath. Working in the Schwinger-Keldysh formalism, we develop an effective action of the particle up to quartic terms. We demonstrate that this quartic effective theory is dual to a stochastic dynamics governed by a non-linear Langevin equation. The Schwinger-Keldysh effective theory, or the equivalent non-linear Langevin dynamics, is insufficient to determine the out of time order correlators (OTOCs) of the particle. To overcome this limitation, we construct an extended effective action in a generalised Schwinger-Keldysh framework. We determine the additional quartic couplings in this OTO effective action and show their dependence on the bath’s 4-point OTOCs. We analyse the constraints imposed on the OTO effective theory by microscopic reversibility and thermality of the bath. We show that these constraints lead to a generalised fluctuation-dissipation relation between the non-Gaussianity in the distribution of the thermal noise experienced by the particle and the thermal jitter in its damping coefficient. The quartic effective theory developed in this work provides extension of several results previously obtained for the cubic OTO dynamics of a Brownian particle.

Stochastic thermodynamics with a Brownian particle in an optical trap (Presentation Recording)

2015 ◽  
Author(s):  
Ignacio A. Martinez ◽  
Édgar Roldán ◽  
Luis Dinis ◽  
Pau Mestres ◽  
Juan M. R. Parrondo ◽  
...  
Keyword(s):  
Brownian Particle ◽  
Optical Trap ◽  
Stochastic Thermodynamics

scholarly journals THE BISTABLE POTENTIAL: AN ARCHETYPE FOR CLASSICAL AND QUANTUM SYSTEMS

2012 ◽  
Vol 26 (12) ◽  
pp. 1241006 ◽  
Author(s):  
B. SPAGNOLO ◽  
P. CALDARA ◽  
A. LA COGNATA ◽  
D. VALENTI ◽  
A. FIASCONARO ◽  
...  
Keyword(s):  
Brownian Particle ◽  
Life Time ◽  
Quantum Systems ◽  
Resonance Phenomenon ◽  
Volterra Model ◽  
Thermal Bath ◽  
Competing Species ◽  
Noise Sources ◽  
Population Distributions ◽  
Bistable Potential

In this work we analyze the transient dynamics of three different classical and quantum systems. First, we consider a classical Brownian particle moving in an asymmetric bistable potential, subject to a multiplicative and additive noise source. We investigate the role of these two noise sources on the life time of the metastable state. A nonmonotonic behavior of the lifetime as a function of both additive and multiplicative noise intensities is found, revealing the phenomenon of noise enhanced stability. Afterward, by using a Lotka–Volterra model, the dynamics of two competing species in the presence of Lévy noise sources is analyzed. Quasiperiodic oscillations and stochastic resonance phenomenon in the dynamics of the competing species are found. Finally the dynamics of a quantum particle subject to an asymmetric bistable potential and interacting with a thermal reservoir is investigated. We use the Caldeira–Leggett model and the approach of the Feynman–Vernon functional in discrete variable representation. We obtain the time evolution of the population distributions in energy eigenstates of the particle, for different values of the coupling strength with the thermal bath.

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