Modulating power delivery in a pulsed ICP discharge via the incorporation of negative feedback mechanisms

2021 ◽  
Vol 130 (16) ◽  
pp. 163304
Author(s):  
Carl L. Smith ◽  
Sang Ki Nam ◽  
Kiho Bae ◽  
Jang-Yeob Lee ◽  
Steven Shannon
Keyword(s):  
Negative Feedback ◽  
Power Delivery ◽  
Feedback Mechanisms

Negative Feedback Mechanisms Surpass the Effect of Intrinsic EGFR Activation during Skin Chemical Carcinogenesis

2012 ◽  
Vol 180 (4) ◽  
pp. 1378-1385 ◽  
Author(s):  
Maik Dahlhoff ◽  
Christian Rose ◽  
Martin Hrabé de Angelis ◽  
Eckhard Wolf ◽  
Marlon R. Schneider
Keyword(s):  
Negative Feedback ◽  
Chemical Carcinogenesis ◽  
Feedback Mechanisms ◽  
Egfr Activation

Synergy of feedback mechanisms in gene regulation systems with promoter and repressor transcription factors

Open Physics ◽  
2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Fedor Šrobár
Keyword(s):  
Gene Regulation ◽  
Transcription Factors ◽  
Negative Feedback ◽  
Regulatory System ◽  
Exact Formulation ◽  
Feedback Mechanisms ◽  
Repressor Proteins ◽  
Positive And Negative Feedback ◽  
Responsive Element ◽  
Genetic Regulatory System

AbstractPresence of feedback mechanisms, both positive and negative, in the gene regulation systems is generally appreciated. The present study proposes a diagrammatic representation of these phenomena that affords their exact formulation and reveals some new facts. Topology of feedback relationships is defined by diagram configuration and quantitative evaluation is afforded by analytical apparatus coming with the diagrams. In particular, criterion for occurrence of bistability and synergy of positive and negative feedback are described in exact manner using the concept of transmission functions associated with diagram edges. The approach is demonstrated on genetic regulatory system comprising two genes whose transcription is controlled by activator and repressor proteins mutually competing for binding to the same responsive element of the DNA.

Peripheral feedback mechanisms acting on the central pattern generators for locomotion in fish and cat

1981 ◽  
Vol 59 (7) ◽  
pp. 713-726 ◽  
Author(s):  
O. Andersson ◽  
H. Forssberg ◽  
S. Grillner ◽  
P. Wallén
Keyword(s):  
Negative Feedback ◽  
Positive Feedback ◽  
Muscle Activity ◽  
Hind Limb ◽  
Central Pattern Generators ◽  
Feedback Mechanisms ◽  
Pattern Generators

The feedback mechanisms taking part in the control of locomotion in cat and fish are reviewed, particularly with regard to position- and movement-related feedback. It is shown that in both fish and cat there is a powerful position-dependent negative feedback which will act only in the position range where the muscle activity normally changes, e.g., from extensor to flexor activity. In addition, there is positive feedback in the middle of the movement range which will act in certain conditions, e.g., to promote and maintain flexor activity during the flexion of the hind limb.

scholarly journals Akt phosphorylates insulin receptor substrate to limit PI3K-mediated PIP3 synthesis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alison L Kearney ◽  
Dougall M Norris ◽  
Milad Ghomlaghi ◽  
Martin Kin Lok Wong ◽  
Sean J Humphrey ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Insulin Receptor ◽  
Negative Feedback ◽  
Insulin Receptor Substrate ◽  
Phosphorylation Sites ◽  
Post Translational Modification ◽  
Feedback Mechanisms ◽  
Signal Flow ◽  
Key Drivers ◽  
Phosphoinositide 3 Kinase

The phosphoinositide 3-kinase (PI3K)-Akt network is tightly controlled by feedback mechanisms that regulate signal flow and ensure signal fidelity. A rapid overshoot in insulin-stimulated recruitment of Akt to the plasma membrane has previously been reported, which is indicative of negative feedback operating on acute timescales. Here, we show that Akt itself engages this negative feedback by phosphorylating insulin receptor substrate (IRS) 1 and 2 on a number of residues. Phosphorylation results in the depletion of plasma membrane-localised IRS1/2, reducing the pool available for interaction with the insulin receptor. Together these events limit plasma membrane-associated PI3K and phosphatidylinositol (3,4,5)-trisphosphate (PIP3) synthesis. We identified two Akt-dependent phosphorylation sites in IRS2 at S306 (S303 in mouse) and S577 (S573 in mouse) that are key drivers of this negative feedback. These findings establish a novel mechanism by which the kinase Akt acutely controls PIP3 abundance, through post-translational modification of the IRS scaffold.

scholarly journals Kinesin Kip2 enhances microtubule growth in vitro through length-dependent feedback on polymerization and catastrophe

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Anneke Hibbel ◽  
Aliona Bogdanova ◽  
Mohammed Mahamdeh ◽  
Anita Jannasch ◽  
Marko Storch ◽  
...  
Keyword(s):  
Motor Activity ◽  
Negative Feedback ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Mitotic Spindles ◽  
Feedback Mechanisms ◽  
Biochemical Pathways ◽  
Mechanical Signaling ◽  
Microtubule Growth

The size and position of mitotic spindles is determined by the lengths of their constituent microtubules. Regulation of microtubule length requires feedback to set the balance between growth and shrinkage. Whereas negative feedback mechanisms for microtubule length control, based on depolymerizing kinesins and severing proteins, have been studied extensively, positive feedback mechanisms are not known. Here, we report that the budding yeast kinesin Kip2 is a microtubule polymerase and catastrophe inhibitor in vitro that uses its processive motor activity as part of a feedback loop to further promote microtubule growth. Positive feedback arises because longer microtubules bind more motors, which walk to the ends where they reinforce growth and inhibit catastrophe. We propose that positive feedback, common in biochemical pathways to switch between signaling states, can also be used in a mechanical signaling pathway to switch between structural states, in this case between short and long polymers.

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