Constructive Role of Internal Noise for the Detection of Weak Stimulation in a Coupled Biological Cell System

2009 ◽  
Vol 25 (07) ◽  
pp. 1327-1331
Author(s):  
LI Hong-Ying ◽  
◽  
◽  
BI Jian-Hong ◽  
MA Juan
Keyword(s):  
Internal Noise ◽  
Cell System ◽  
Biological Cell ◽  
Weak Stimulation

THE ROLE OF INTERNAL NOISE FOR OPTIMAL INTRACELLULAR CALCIUM SIGNALING IN COUPLED BIOLOGICAL CELL SYSTEM

2011 ◽  
Vol 10 (01) ◽  
pp. 31-39 ◽  
Author(s):  
HONGYING LI ◽  
JIANHONG BI
Keyword(s):  
Calcium Signaling ◽  
Intracellular Calcium ◽  
Cell Size ◽  
Internal Noise ◽  
System Size ◽  
Cell System ◽  
Calcium Oscillations ◽  
Biological Cell ◽  
Intracellular Calcium Signaling

We have studied the role of internal noise for intracellular calcium signaling in coupled biological cell system. It is found that internal noise can induce calcium oscillations and the performance of such oscillations shows two peaks with the variation of the cell size-Ω for any cell chain length-N, indicating the occurrence of system size bi-resonance or internal noise stochastic bi-resonance, which may be very relevant to the canard explosion. We also find that there exists an optimal cell chain length-N for the first peak at which the collective calcium oscillations show the best performance, it is also a phenomenon of "system size resonance". It is interesting to note that one of the optimal cell sizes is present at Ω ~ 103μm3, which is close to a real living cell size in vivo.

Constructive Role of Internal Noise for the Detection of Weak Signal in Cell System

2008 ◽  
Vol 24 (12) ◽  
pp. 2203-2206 ◽  
Author(s):  
H LI ◽  
J MA ◽  
Z HOU ◽  
H XIN
Keyword(s):  
Internal Noise ◽  
Cell System ◽  
Weak Signal

Stochastic models in cell kinetics

1988 ◽  
Vol 25 (A) ◽  
pp. 91-111
Author(s):  
Peter J. Brockwell
Keyword(s):  
Life Cycle ◽  
Stochastic Models ◽  
Death Rate ◽  
Cell Kinetics ◽  
Branching Processes ◽  
Experimental Studies ◽  
Renewal Theory ◽  
Biological Cell ◽  
Age Dependent

We discuss the role of stochastic processes in modelling the life-cycle of a biological cell and the growth of cell populations. Results for multiphase age-dependent branching processes have proved invaluable for the interpretation of many of the basic experimental studies of the life-cycle. Moreover problems from cell kinetics, in particular those related to diurnal rhythm in cell-growth, have stimulated research into ‘periodic' renewal theory, and the asymptotic behaviour of populations of cells with periodic death rate.

Stochastic models in cell kinetics

1988 ◽  
Vol 25 (A) ◽  
pp. 91-111
Author(s):  
Peter J. Brockwell
Keyword(s):  
Life Cycle ◽  
Stochastic Models ◽  
Death Rate ◽  
Cell Kinetics ◽  
Branching Processes ◽  
Experimental Studies ◽  
Renewal Theory ◽  
Biological Cell ◽  
Age Dependent

We discuss the role of stochastic processes in modelling the life-cycle of a biological cell and the growth of cell populations. Results for multiphase age-dependent branching processes have proved invaluable for the interpretation of many of the basic experimental studies of the life-cycle. Moreover problems from cell kinetics, in particular those related to diurnal rhythm in cell-growth, have stimulated research into ‘periodic' renewal theory, and the asymptotic behaviour of populations of cells with periodic death rate.

scholarly journals Immunomodulatory role of phagocyte-derived chloramines involving lymphocyte glutathione

1993 ◽  
Vol 2 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Véronique Witko-Sarsat ◽  
Anh Thu Nguyen ◽  
Béatrice Descamps-Latscha
Keyword(s):  
Oxidative Stress ◽  
Reduced Glutathione ◽  
Human Lymphocytes ◽  
Cell System ◽  
Polymorphonuclear Neutrophils ◽  
Myristate Acetate ◽  
Defensive Role ◽  
Free Model ◽  
A Cell

This study shows that human lymphocytes markedly decrease chloramines (long-lived oxidants) generated by polymorphonuclear neutrophils (PMN) after stimulation by phorbol-myristate-acetate or opsonized zymosan. In a cell-free model, reduced glutathione (GSH) scavenged chloramines, giving rise to oxidized glutathione (GSSG). In the cell system, treatment of lymphocytes with autologous PMN-derived chloramines induced a profound decrease in their total and reduced glutathione (GSH) content and markedly inhibited their proliferate responses to concanavalin-A and, to a lesser extent, phytohaemagglutinin. It is concluded that (i) lymphocytes may play a defensive role against phagocyte-derived oxidative stress by scavenging chloramines, and (ii) as this effect which is mediated by GSH affects lymphocyte proliferative responses, it may help to elucidate the still obscure mechanisms of oxidative stress associated immunodeficiency.

Heat diffusion as a source of aerodynamic sound

1976 ◽  
Vol 78 (1) ◽  
pp. 1-31 ◽  
Author(s):  
A. J. Kempton
Keyword(s):  
Vibrational Energy ◽  
Internal Noise ◽  
Three Dimensions ◽  
Heat Diffusion ◽  
Mean Flow ◽  
Noise Sources ◽  
Low Frequencies ◽  
Aerodynamic Sound ◽  
Specific Heats

The paper examines the role of heat diffusion as an internal noise source in aeroengines and as a source of noise in the mixing of hot jets. We consider a number of model problems and find that the sound induced by unsteady heat transfer can show an unusually weak dependence on the mean flow velocityU, the intensity scaling asU3in three dimensions. At low enough velocities diffusion effects will overwhelm other noise sources, but we have failed in our search for a significant practical situation in which we can prove that sound generated by diffusion clearly dominates over that excited by unsteady aerodynamic forces; they are sometimes comparable.We examine the possibility that diffusive monopole sources feature in the noise of hot jets using model problems in the linear case and using dimensional analysis in the nonlinear case, and conclude that no significant monopole exists when the specific heats are constant. But they are not constant at low frequencies when, for example, heat flows into and out of vibrational energy modes; then an important monopole source is present. This source shows an unusually complicated scale effect.

Role of the Subsequently Activated Receptors in Electro-Acupuncture of the Rat

1981 ◽  
Vol 09 (02) ◽  
pp. 164-170 ◽  
Author(s):  
Kenji Kawakita ◽  
Masaya Hwa
Keyword(s):  
Common Peroneal Nerve ◽  
Muscular Contraction ◽  
Tail Flick ◽  
Acupuncture Analgesia ◽  
Direct Excitation ◽  
Afferent Fibers ◽  
Weak Intensity ◽  
Weak Stimulation ◽  
Subsequent Activation

Role of the subsequently excited receptors elicited by tetanic muscular contraction in electro-acupuncture analgesia was examined. Conditioning stimulation of the nerve (CPN) as well as electro-acupuncture induced a significant delay of the tail flick latencies of the rat with weak intensity of stimulus (1.01-1.5 x DFT), and this effect was abolished after section of the nerve at a point distal to the stimulating electrode. Electrophysiological data indicate that a small amplitude of the A large fiber group's potential was recorded with the intensity range of 1.0-1.5 x DFT. These facts suggest that the analgesic effect induced by weak stimulation is not the result of direct excitation of afferent fibers but the result of subsequent activation of receptors provoked by tetanic muscular contraction. The possible receptors are proposed and their participation in acupuncture analgesia also discussed. CPN = the common peroneal nerve; DFT = dorsal flexion threshold (1.0 x DFT = 1.15 x Tα).

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