scholarly journals Ca2+ Signaling in the Inner Ear

Physiology ◽  
2007 ◽  
Vol 22 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Fabio Mammano ◽  
Mario Bortolozzi ◽  
Saida Ortolano ◽  
Fabio Anselmi
Keyword(s):  
Feedback Control ◽  
Inner Ear ◽  
Control Mechanisms ◽  
Sensory Receptors ◽  
Key Players ◽  
Mechanical Disturbances

The inner ear contains delicate sensory receptors that have adapted to detect the minutest mechanical disturbances. Ca2+ ions are implicated in all steps of the transduction process, as well as in its regulation by an impressive ensemble of finely tuned feedback control mechanisms. Recent studies have unveiled some of the key players, but things do not sound quite right yet.

A NEW APPROACH FOR INVESTIGATING HYPOTHALAMO-PITUITARY-GONADAL AND ADRENAL FEEDBACK CONTROL MECHANISMS: ACTIVE IMMUNIZATION WITH STEROIDS

1974 ◽  
Vol 76 (3) ◽  
pp. 556-569 ◽  
Author(s):  
E. Nieschlag ◽  
K. H. Usadel ◽  
H. K. Kley ◽  
U. Schwedes ◽  
K. Schöffling ◽  
...  
Keyword(s):  
Feedback Control ◽  
Leydig Cells ◽  
Positive Response ◽  
Active Immunization ◽  
Biologically Active ◽  
Control Group ◽  
Control Mechanisms ◽  
New Approach ◽  
Biological Neutralization ◽  
Group Serum

ABSTRACT A new method for the investigation of hypothalamo-pituitary-gonadal and adrenal feedback control mechanisms based on the biological neutralization of gonadal and adrenal steroids by active immunization is proposed. The regulatory influence of a given steroid in the feedback control is proved when reduction of the free, biologically active fraction of this steroid caused by antibody binding induces a positive response of the pituitary, thus effecting gonadal or adrenal hypertrophy and hyperfunction. The advantages and limitations of the new model are demonstrated by the effects of active immunization of rabbits with cortisol (F), aldosterone (Aldo), dehydroepiandrosterone (DHA), androstenedione (Δ4-A), testosterone (T), 5α-dihydrotestosterone (5α-DHT), 5β-DHT and oestradiol (E2). In the immunized animals and in a control group serum concentrations of total corticosteroids (TC), DHA, T, Δ4-A, E1, E2, LH and FSH, the percentage of binding of steroids in serum and the specificity of the antisera are determined. The testes are evaluated by histometry and the nuclear volume of the adrenocortical and Leydig cells is measured.

scholarly journals The role of feedback control mechanisms on the establishment of oscillatory regimes in the Ras/cAMP/PKA pathway in S. cerevisiae

2012 ◽  
Vol 2012 (1) ◽  
Author(s):  
Daniela Besozzi ◽  
Paolo Cazzaniga ◽  
Dario Pescini ◽  
Giancarlo Mauri ◽  
Sonia Colombo ◽  
...  
Keyword(s):  
Feedback Control ◽  
Control Mechanisms ◽  
Pka Pathway

Articulation and Stress/Juncture Production Under Oral Anesthetization and Masking

1971 ◽  
Vol 14 (2) ◽  
pp. 271-282 ◽  
Author(s):  
Sylvia A. Gammon ◽  
Philip J. Smith ◽  
Raymond G. Daniloff ◽  
Chin W. Kim
Keyword(s):  
Feedback Control ◽  
Oral Cavity ◽  
White Noise ◽  
Speech Production ◽  
Local Anesthesia ◽  
The Other ◽  
Control Mechanisms ◽  
Combined Stress ◽  
Noise Masking ◽  
High Degree

Eight subjects, half of them naive and the other half aware of the purpose of the experiment, spoke 30 pairs of sentences involving the production of intricate stress/juncture patterns along with a passage containing all major consonant phonemes in English in various intraword positions. All subjects spoke all materials under: (1) normal conditions, (2) 110 dB re: 0.0002 ubar white noise masking, (3) extensive local anesthesia of the oral cavity, and (4) masking and anesthesia combined. Stress and juncture patterns were correctly produced despite all feedback disruption, and there was no difference between naive and aware subjects. Noise masking produced a decline in speech quality and a disruption of normal rhythm, both of which were even more seriously affected by anesthesia and anesthesia plus masking. There were no significant vowel misarticulations under any condition, but there was nearly a 20% rate of consonant misartiqulation under anesthesia and anesthesia and noise. Mis-articulation was most severe for fricatives and affricates in the labial and alveolar regions, presumably because these productions demand a high degree of precision of articulate shape and location and hence, intact feedback. Results are discussed in terms of feedback-control mechanisms for speech production.

scholarly journals Modelling Robust Feedback Control Mechanisms That Ensure Reliable Coordination of Histone Gene Expression with DNA Replication

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0165848
Author(s):  
Andrea Christopher ◽  
Heike Hameister ◽  
Holly Corrigall ◽  
Oliver Ebenhöh ◽  
Berndt Müller ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Feedback Control ◽  
Histone Gene ◽  
Control Mechanisms ◽  
Histone Gene Expression

scholarly journals CoRa –A general approach for quantifying biological feedback control

2020 ◽  
Author(s):  
Mariana Gómez-Schiavon ◽  
Hana El-Samad
Keyword(s):  
Feedback Control ◽  
Control Systems ◽  
General Framework ◽  
Control Mechanism ◽  
Biological Molecules ◽  
Control Mechanisms ◽  
Biological Processes ◽  
Biological Feedback ◽  
Feedback Systems ◽  
Feedback Control Systems

AbstractFeedback control is a fundamental underpinning of life, underlying homeostasis of biological processes at every scale of organization, from cells to ecosystems. The ability to evaluate the contribution and limitations of feedback control mechanisms operating in cells is a critical step for understanding and ultimately designing feedback control systems with biological molecules. Here, we introduce CoRa –or ControlRatio–, a general framework that quantifies the contribution of a biological feedback control mechanism to adaptation using a mathematically controlled comparison to an identical system that does not contain the feedback. CoRa provides a simple and intuitive metric with broad applicability to biological feedback systems.

scholarly journals Reaction to disturbances of a walking leg during stance

2000 ◽  
Vol 203 (7) ◽  
pp. 1211-1223 ◽  
Author(s):  
C. Bartling ◽  
J. Schmitz
Keyword(s):  
Feedback Control ◽  
Three Dimensional ◽  
Force Transducer ◽  
The Body ◽  
Control Mechanisms ◽  
Control Schemes ◽  
Stick Insects ◽  
Reaction Forces ◽  
Negative Feedback Control ◽  
Model Circuit

The ground reaction forces exerted by the legs of freely walking stick insects, Carausius morosus, were recorded during normal and perturbed locomotion. The animals walked along a path into which a three-dimensional force transducer was integrated. The transducer registered all three components of the forces produced by a single leg when, by chance, it walked on the force platform. The stiffness of the walking surface was found to be a critical variable affecting the forces and the trajectories of leg movements during undisturbed walking. The forces produced by a leg were considerably smaller and the trajectories were closer to the body during walking on soft versus stiff surfaces. Perturbations during stance were generated by moving the platform in various directions within the horizontal plane and at two different rates. Perturbations were applied either immediately after leg contact or after a delay of 300 ms. The reactions to these disturbances were compatible with the hypothesis that the velocity of leg movement is under negative feedback control. This interpretation is also supported by comparison with simulations based upon other control schemes. We propose a model circuit that provides a combination of negative and positive feedback control mechanisms to resolve the apparent discrepancies between our results and those of previous studies.

Acoustic communication

2018 ◽  
Author(s):  
Heiner Römer
Keyword(s):  
Acoustic Communication ◽  
Background Noise ◽  
Near Field ◽  
Background Information ◽  
Natural Environments ◽  
Far Field ◽  
Sensory Receptors ◽  
Substrate Vibration ◽  
Field Sound ◽  
Mechanical Disturbances

This chapter, takes a broad look at insect acoustic communication, by including near-field and far-field sound, as well as substrate vibration, as signals. These mechanical disturbances differ greatly in their physical properties—they propagate in their natural environments over distances that can span from a few millimetres up to several hundred metres. Therefore, background information is provided to understand how the insect sound-emitting systems for the different signals work and in which behavioral contexts they are used. Evidence is also provided to describe the substantial changes signals undergo on their way to receivers, the effects of background noise on communication and how unintended receivers may represent costs in this system. Finally, a short overview of the structure and evolution of the tremendous diversity of sensory receptors is presented.

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