scholarly journals The primary dipole of flipper probes

2021 ◽  
Vol 57 (32) ◽  
pp. 3913-3916
Author(s):  
José García-Calvo ◽  
Javier López-Andarias ◽  
Naomi Sakai ◽  
Stefan Matile
Keyword(s):  
Switching Cycle ◽  
Membrane Tension ◽  
Central Paradigm

The need of the primary dipole of flipper mechanophores has often been claimed but never confirmed. Here, a complete sulfur switching cycle is realized to prove that the central paradigm of fluorescent membrane tension probes is correct.

Control of an adiabatic continuous reactor by feeding catalyst

1980 ◽  
Vol 45 (11) ◽  
pp. 2903-2918 ◽  
Author(s):  
Josef Horák ◽  
Zina Valášková ◽  
František Jiráček
Keyword(s):  
Steady State ◽  
Reaction Temperature ◽  
Continuous Reactor ◽  
Control Element ◽  
Inlet Temperature ◽  
Switching Cycle ◽  
Point Temperature ◽  
Set Point ◽  
Constant Rate ◽  
Laboratory Reactor

Algorithms have been presented, analyzed and experimentally tested to stabilize the reaction temperature at constant inlet temperature and composition of the feed by controlled dispensing of the catalyst. The information for the control element is the course of the reaction temperature. If the temperature of the reaction mixture is below the set point, the catalyst is being fed into the reactor at a constant rate. If the reaction temperature is higher the catalyst dispenser is blocked; dispensing of the catalyst is not resumed until the set point temperature has been reached again. The amount of catalyst added is a function of the duration of the switching cycle. The effect has been discussed of the form of this function on the course of the switching cycle. The results have been tested experimentally on a laboratory reactor controlled in an unstable steady state.

The Tangled Tale of Phase Space

2018 ◽  
Author(s):  
David D. Nolte
Keyword(s):  
Phase Space ◽  
Chaotic Behavior ◽  
Three Body Problem ◽  
Henri Poincaré ◽  
History Of ◽  
The Stability ◽  
Three Body ◽  
Space Phase ◽  
Central Paradigm ◽  
System Phase

This chapter presents the history of the development of the concept of phase space. Phase space is the central visualization tool used today to study complex systems. The chapter describes the origins of phase space with the work of Joseph Liouville and Carl Jacobi that was later refined by Ludwig Boltzmann and Rudolf Clausius in their attempts to define and explain the subtle concept of entropy. The turning point in the history of phase space was when Henri Poincaré used phase space to solve the three-body problem, uncovering chaotic behavior in his quest to answer questions on the stability of the solar system. Phase space was established as the central paradigm of statistical mechanics by JW Gibbs and Paul Ehrenfest.

Introduction

2020 ◽  
pp. xxii-13
Author(s):  
Ryan Light ◽  
James Moody
Keyword(s):  
Social Networks ◽  
Social Network ◽  
Social Network Analysis ◽  
Network Analysis ◽  
Bibliometric Analysis ◽  
Social Life ◽  
New Directions ◽  
Central Paradigm

This chapter provides an introduction to this volume on social networks. It argues that social network analysis is greater than a method or data, but serves as a central paradigm for understanding social life. The chapter offers evidence of the influence of social network analysis with a bibliometric analysis of research on social networks. This analysis underscores how pervasive network analysis has become and highlights key theoretical and methodological concerns. It also introduces the sections of the volume broadly structured around theory, methods, broad conceptualizations like culture and temporality, and disciplinary contributions. The chapter concludes by discussing several promising new directions in the field of social network analysis.

scholarly journals Protocol to measure the membrane tension and bending modulus of cells using optical tweezers and scanning electron microscopy

2021 ◽  
Vol 2 (1) ◽  
pp. 100283
Author(s):  
Pedro Pompeu ◽  
Pedro S. Lourenço ◽  
Diney S. Ether ◽  
Juliana Soares ◽  
Jefte Farias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Tweezers ◽  
Membrane Tension ◽  
Bending Modulus ◽  
Scanning Electron

scholarly journals State dependent effects on the frequency response of prestin’s real and imaginary components of nonlinear capacitance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joseph Santos-Sacchi ◽  
Dhasakumar Navaratnam ◽  
Winston J. T. Tan
Keyword(s):  
Frequency Response ◽  
Outer Hair Cell ◽  
Absolute Magnitude ◽  
Total Charge ◽  
Charge Movement ◽  
Membrane Tension ◽  
Nonlinear Capacitance ◽  
Complex Component ◽  
Trade Offs ◽  
Voltage Dependent

AbstractThe outer hair cell (OHC) membrane harbors a voltage-dependent protein, prestin (SLC26a5), in high density, whose charge movement is evidenced as a nonlinear capacitance (NLC). NLC is bell-shaped, with its peak occurring at a voltage, Vh, where sensor charge is equally distributed across the plasma membrane. Thus, Vh provides information on the conformational state of prestin. Vh is sensitive to membrane tension, shifting to positive voltage as tension increases and is the basis for considering prestin piezoelectric (PZE). NLC can be deconstructed into real and imaginary components that report on charge movements in phase or 90 degrees out of phase with AC voltage. Here we show in membrane macro-patches of the OHC that there is a partial trade-off in the magnitude of real and imaginary components as interrogation frequency increases, as predicted by a recent PZE model (Rabbitt in Proc Natl Acad Sci USA 17:21880–21888, 2020). However, we find similar behavior in a simple 2-state voltage-dependent kinetic model of prestin that lacks piezoelectric coupling. At a particular frequency, Fis, the complex component magnitudes intersect. Using this metric, Fis, which depends on the frequency response of each complex component, we find that initial Vh influences Fis; thus, by categorizing patches into groups of different Vh, (above and below − 30 mV) we find that Fis is lower for the negative Vh group. We also find that the effect of membrane tension on complex NLC is dependent, but differentially so, on initial Vh. Whereas the negative group exhibits shifts to higher frequencies for increasing tension, the opposite occurs for the positive group. Despite complex component trade-offs, the low-pass roll-off in absolute magnitude of NLC, which varies little with our perturbations and is indicative of diminishing total charge movement, poses a challenge for a role of voltage-driven prestin in cochlear amplification at very high frequencies.

Fluorescent Membrane Tension Probes for Early Endosomes

2021 ◽  
Author(s):  
Francesca Piazzolla ◽  
Vincent Mercier ◽  
Lea Assies ◽  
Naomi Sakai ◽  
Aurelien Roux ◽  
...  
Keyword(s):  
Membrane Tension ◽  
Early Endosomes

scholarly journals Membrane Tension Locks In Pluripotency

2021 ◽  
Vol 28 (2) ◽  
pp. 175-176
Author(s):  
Jonathon M. Muncie ◽  
Valerie M. Weaver
Keyword(s):  
Membrane Tension
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