scholarly journals Two paradigms of bistable plaid motion reveal independent mutual inhibition processes

2019 ◽  
Vol 19 (4) ◽  
pp. 5
Author(s):  
Jean-Michel Hupé ◽  
Camilo Miguel Signorelli ◽  
David Alais
Keyword(s):  
Mutual Inhibition ◽  
Plaid Motion

The role of a metabolic intermediate in the biodegradation of inhibitory substrates

1997 ◽  
Vol 36 (10) ◽  
pp. 27-36 ◽  
Author(s):  
P. Mungkarndee ◽  
S. M. Rao Bhamidimarri ◽  
A. J. Mawson ◽  
R. Chong
Keyword(s):  
The Other ◽  
Metabolic Product ◽  
Dichlorophenoxyacetic Acid ◽  
Mutual Inhibition ◽  
Metabolic Intermediate ◽  
Batch Cultures ◽  
Ortho Cresol ◽  
2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

scholarly journals ArhGAP15, a Rac-specific GTPase-activating Protein, Plays a Dual Role in Inhibiting Small GTPase Signaling

2013 ◽  
Vol 288 (29) ◽  
pp. 21117-21125 ◽  
Author(s):  
Maria Radu ◽  
Sonali J. Rawat ◽  
Alexander Beeser ◽  
Anton Iliuk ◽  
Weiguo Andy Tao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Protein Microarray ◽  
Small Gtpases ◽  
Dual Role ◽  
Small Gtpase ◽  
Ph Domain ◽  
Gtpase Activating Protein ◽  
Mutual Inhibition ◽  
Negative Role ◽  
Pak Kinase

Signaling from small GTPases is a tightly regulated process. In this work we used a protein microarray screen to identify the Rac-specific GAP, ArhGAP15, as a substrate of the Rac effectors Pak1 and Pak2. In addition to serving as a substrate of Pak1/2, we found that ArhGAP15, via its PH domain, bound to these kinases. The association of ArhGAP15 to Pak1/2 resulted in mutual inhibition of GAP and kinase catalytic activity, respectively. Knock-down of ArhGAP15 resulted in activation of Pak1/2, both indirectly, as a result of Rac activation, and directly, as a result of disruption of the ArhGAP15/Pak complex. Our data suggest that ArhGAP15 plays a dual negative role in regulating small GTPase signaling, by acting at the level of the GTPase itself, as well interacting with its effector, Pak kinase.

scholarly journals Dissociable roles of cortical excitation-inhibition balance during patch-leaving versus value-guided decisions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luca F. Kaiser ◽  
Theo O. J. Gruendler ◽  
Oliver Speck ◽  
Lennart Luettgau ◽  
Gerhard Jocham
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Ventromedial Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Mutual Inhibition ◽  
Dorsal Anterior Cingulate Cortex ◽  
Cortical Excitation ◽  
The Cost

AbstractIn a dynamic world, it is essential to decide when to leave an exploited resource. Such patch-leaving decisions involve balancing the cost of moving against the gain expected from the alternative patch. This contrasts with value-guided decisions that typically involve maximizing reward by selecting the current best option. Patterns of neuronal activity pertaining to patch-leaving decisions have been reported in dorsal anterior cingulate cortex (dACC), whereas competition via mutual inhibition in ventromedial prefrontal cortex (vmPFC) is thought to underlie value-guided choice. Here, we show that the balance between cortical excitation and inhibition (E/I balance), measured by the ratio of GABA and glutamate concentrations, plays a dissociable role for the two kinds of decisions. Patch-leaving decision behaviour relates to E/I balance in dACC. In contrast, value-guided decision-making relates to E/I balance in vmPFC. These results support mechanistic accounts of value-guided choice and provide evidence for a role of dACC E/I balance in patch-leaving decisions.

scholarly journals Interaction betweenPseudomonas aeruginosaandAspergillus fumigatusin cystic fibrosis

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5931 ◽  
Author(s):  
Jingming Zhao ◽  
Wencheng Yu
Keyword(s):  
Cystic Fibrosis ◽  
Antibiotic Sensitivity ◽  
Pathogenic Microorganisms ◽  
Mutual Inhibition ◽  
Sensing System ◽  
High Incidence ◽  
Volatile Organic ◽  
Metabolic Transformation ◽  
Small Colony ◽  
Combined Infection

BackgroundCystic fibrosis (CF) is a disease characterized by chronic airway infection with a high incidence and poor prognosis.Pseudomonas aeruginosaandAspergillus fumigatusare pathogens commonly found in CF patients. Clinically, these two microorganisms often coexist in the airway of CF patients. Combined infection withP. aeruginosaandA. fumigatusresults in worsening lung function and clinical condition.MethodsIn this review, we focus on the mutual inhibition and promotion mechanisms ofP. aeruginosaandA. fumigatusin CF patients. We also summarized the mechanisms of the interaction between these pathogenic microorganisms.ResultsP. aeruginosainhibitsA. fumigatusgrowth through the effects of phenazines, the quorum sensing system, iron competition, bacteriophages, and small colony variants.P. aeruginosainducesA. fumigatusgrowth through volatile organic compounds and subbacteriostatic concentrations of phenazines.A. fumigatusinterferes withP. aeruginosa, affecting its metabolic growth via phenazine metabolic transformation, gliotoxin production, and reduced antibiotic sensitivity.DiscussionCoexistence ofP. aeruginosaandA. fumigatuscan lead to both mutual inhibition and promotion. In different stages of CF disease, the interaction between these two pathogenic microorganisms may shift between promotion and inhibition. A discussion of the mechanisms ofP. aeruginosaandA. fumigatusinteraction can be beneficial for further treatment of CF patients and for improving the prognosis of the disease.

scholarly journals Augmenting Flexibility: Mutual Inhibition Between Inhibitory Neurons Expands Functional Diversity

2020 ◽  
Author(s):  
Belle Liu ◽  
Alexander James White ◽  
Chung-Chuan Lo
Keyword(s):  
Dynamical Systems ◽  
Bifurcation Theory ◽  
Neural Circuits ◽  
Feedback Inhibition ◽  
Central Pattern Generators ◽  
Recurrent Network ◽  
Inhibitory Neurons ◽  
Mutual Inhibition ◽  
Input Type ◽  
Pattern Generators

AbstractOne of the most intriguing observations of recurrent neural circuits is their flexibility. Seemingly, this flexibility extends far beyond the ability to learn, but includes the ability to use learned procedures to respond to novel situations. Here, we report that this flexibility arises from the synergistic interplay between recurrent mutual excitation and recurrent mutual inhibition. Specifically, we show that mutual inhibition is critical in expanding the functionality of the circuit, far beyond what feedback inhibition alone can accomplish. By taking advantage of dynamical systems theory and bifurcation analysis, we show mutual inhibition doubles the number of cusp bifurcations in the system in small neural circuits. As a concrete example, we build a simulation model of a class of functional motifs we call Coupled Recurrent inhibitory and Recurrent excitatory Loops (CRIRELs). These CRIRELs have the advantage of being multi-functional, performing a plethora of functions, including decisions, switches, toggles, central pattern generators, depending solely on the input type. We then use bifurcation theory to show how mutual inhibition gives rise to this broad repertoire of possible functions. Finally, we demonstrate how this trend also holds for larger networks, and how mutual inhibition greatly expands the amount of information a recurrent network can hold.

The Acoustic Behaviour of the Bush Cricket Pholidoptera Griseoaptera

1966 ◽  
Vol 45 (1) ◽  
pp. 15-30
Author(s):  
M. D. R. JONES
Keyword(s):  
Chirp Rate ◽  
Mutual Inhibition ◽  
Acoustic Behaviour ◽  
Close Proximity ◽  
Hearing Range ◽  
High Level ◽  
Bush Cricket

1. Pholidoptera griseoptera males singing alone or alternating with other males produce short chirps of three or occasionally four syllables (wing movements) lasting about 100 msec. (at 18° C.). 2. Close proximity of singing males may result in rivalry behaviour where chirps lasting up to about 4 sec. may be produced. The long chirp is not usually continuous but has a number of breaks or ‘stutters’. 3. The syllables and syllable rates in the long chirp and short chirp are essentially similar. 4. At the end of a short chirp or of a group of syllables in the long chirp, the syllable rate is decreased, possibly indicating a waning of excitation of the syllable-producing mechanism. 5. Males within hearing range of each other alternate or occasionally synchronize their short chirps. The pattern of this interaction appears to be determined mainly by mutual inhibition between the singing males. Mutual excitation may cause an in crease in chirp rate during the interaction. 6. Chirping may be controlled by a pacemaker system which can be inhibited or excited by its various inputs. A long chirp is possibly the result of a high level of excitation of this mechanism. 7. Alternation singing and rivalry behaviour between males may have a territorial significance.

Contribution of the hybrid component to the structure and properties of ceramics based on metastable phases Al2O3

2021 ◽  
pp. 127-136
Author(s):  
A. V. Maletsky ◽  
T. E. Konstantinova ◽  
D. R. Belichko ◽  
G. K. Volkova ◽  
V. V. Burkhovetsky
Keyword(s):  
Mechanical Properties ◽  
Yttrium Aluminum Garnet ◽  
Metastable Phase ◽  
Physical And Mechanical Properties ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Mutual Inhibition ◽  
X Ray ◽  
Tetragonal Lattice ◽  
Yttrium Aluminum

The paper presents results of the study of the effect of doping with yttrium oxide on ceramics of the composition (γ + θ) Al2O3 + nY2O3 (n = 0, 1, 2, 3 wt%), sintered at 1550°C for 2 h, from powders of the specified composition annealed at temperatures of 500 , 800, 1000°С. X-ray diffraction analysis established the formation in ceramics of yttrium aluminum garnet Y3Al5O12 (YAG) and a metastable phase of the same composition with a tetragonal lattice type in powders at temperatures above 1200°C. The effect of YAG on the physical and mechanical properties was established: high properties were demonstrated by ceramics of the composition α-Al2O3 + 2wt% Y2O3, obtained from a powder annealed at 1000°C. In addition, high physical and mechanical properties were observed in ceramics of the composition α-Al2O3 + 0wt% Y2O3, obtained from a powder annealed at 800°C. The effect of the so-called “mutual protection against crystallization” was discovered, which consists in the mutual inhibition of crystallization processes in powders of the Al2O3 – Y2O3 system.

Computer Simulation of Stepping in the Hind Legs of the Cat: An Examination of Mechanisms Regulating the Stance-to-Swing Transition

2005 ◽  
Vol 94 (6) ◽  
pp. 4256-4268 ◽  
Author(s):  
Örjan Ekeberg ◽  
Keir Pearson
Keyword(s):  
Computer Simulation ◽  
Three Dimensional ◽  
Swing Phase ◽  
Relative Importance ◽  
Mutual Inhibition ◽  
Small Perturbations ◽  
Position Signal ◽  
Extensor Muscles ◽  
Force Signal ◽  
Hip Extension

Physiological studies in walking cats have indicated that two sensory signals are involved in terminating stance in the hind legs: one related to unloading of the leg and the other to hip extension. To study the relative importance of these two signals, we developed a three-dimensional computer simulation of the cat hind legs in which the timing of the swing-to-stance transition was controlled by signals related to the force in ankle extensor muscles, the angle at the hip joint, or a combination of both. Even in the absence of direct coupling between the controllers for each leg, stable stepping was easily obtained using either a combination of ankle force and hip position signals or the ankle force signal alone. Stable walking did not occur when the hip position signal was used alone. Coupling the two controllers by mutual inhibition restored stability, but it did not restore the correct timing of stepping of the two hind legs. Small perturbations applied during the swing phase altered the movement of the contralateral leg in a manner that tended to maintain alternating stepping when the ankle force signal was included but tended to shift coordination away from alternating when the hip position signal was used alone. We conclude that coordination of stepping of the hind legs depends critically on load-sensitive signals from each leg and that mechanical linkages between the legs, mediated by these signals, play a significant role in establishing the alternating gait.

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