Related Experiment Video
Updated: Jun 5, 2026
11:44
Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators
Published on: August 15, 2014
Different effects of redundant feedback loops on a bistable switch
Maria Rosa Domingo-Sananes1, Bela Novak
1Department of Biochemistry, Oxford Centre for Integrative Systems Biology, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
Chaos (Woodbury, N.Y.)
|January 5, 2011
Summary
Bistable switches in cells rely on feedback loops for decision-making. This study reveals that the architecture of these feedback loops, even if redundant, significantly impacts how cellular systems switch states.
Area of Science:
- Cellular and Molecular Biology
- Biochemistry
- Systems Biology
Background:
- Bistable switches are crucial for cellular decision-making.
- Bistability arises from positive or double-negative feedback loops, requiring nonlinearity.
- Nonlinearity can stem from synergistic feedback or ultrasensitivity, or both.
Purpose of the Study:
- To analyze a biochemical regulatory network controlling a eukaryotic cell cycle transition.
- To investigate the role of multiple redundant feedback loops and nonlinearity in bistability.
- To determine if different feedback loop architectures affect system switching points.
Main Methods:
- Analysis of a biochemical regulatory network controlling a crucial cell cycle transition.
- Mathematical modeling to study the effects of feedback loop architecture on system dynamics.
- Identification of saddle-node bifurcations and their dependence on feedback mechanisms.
Main Results:
- Two redundant feedback loops in the analyzed network have distinct effects on saddle-node bifurcations.
- The specific architecture of feedback loops influences the system's switching thresholds.
- Differences in feedback loop architecture lead to varied effects on system behavior.
Conclusions:
- The architecture of feedback loops, not just their presence, is critical for bistable system function.
- Even functionally similar feedback loops can have divergent impacts due to structural differences.
- This finding may generalize to other bistable biological systems with redundant feedback loops.
Related Concept Videos
01:24Effects of feedback
Feedback in control systems plays a critical role in shaping various operational parameters, extending beyond simple error reduction to influence stability, bandwidth, gain, impedance, and sensitivity. Understanding these effects requires examining a basic feedback system characterized by defined input, output, error, and feedback signals.
Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents...
Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents...
01:22Switching of BJT
Switching behavior in Bipolar Junction Transistors (BJTs) is a fundamental aspect utilized in various electronic circuits, particularly for digital logic applications like switches and amplifiers. In a typical switching circuit, a BJT alternates between cut-off and saturation modes, corresponding to the "off" and "on" states, respectively, thus behaving like an ideal switch.
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are reverse-biased. The...
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are reverse-biased. The...
01:07Cell Signaling Feedback Loops
Positive and negative feedback loops are crucial for regulating biological signaling systems. These feedback loops are processes that connect output signals to their inputs.
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
01:18Positive and Negative Feedback Loops
Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis ("steady state"). Examples of these changes include regulation of the level of glucose or calcium in the blood or internal responses to external temperatures. Homeostasis requires maintaining an internal dynamic equilibrium:
01:01Feedback Loops
In most cases, excessive hormone production is prevented by negative feedback—a loop that starts with a stimulus inducing the release of a particular substance, like a hormone, to maintain a certain level before triggering a signal that results in a decrease in further release of the hormone.
01:26Feedback control systems
Feedback control systems are categorized in various ways based on their design, analysis, and signal types.
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...