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Calls out of chaos: the adaptive significance of nonlinear phenomena in mammalian vocal production
It is suggested that nonlinear phenomena may subserve individual recognition and the estimation of size or fluctuating asymmetry from vocalizations, and neurally ‘cheap’ unpredictability may serve the valuable adaptive function of making chaotic calls difficult to predict and ignore.
SUBHARMONICS, BIPHONATION, AND DETERMINISTIC CHAOS IN MAMMAL VOCALIZATION
It is suggested that a variety of nonlinear phenomena including subharmonics, biphonation, and deterministic chaos are normally occurring phonatory events in mammalian vocalizations.
Bifurcations in an asymmetric vocal-fold model.
A two-mass model of vocal-fold vibrations is analyzed with methods from nonlinear dynamics and it is shown that a sufficiently large tension imbalance of the left and right vocal fold induces bifurcations to subharmonic regimes, toroidal oscillations, and chaos.
Spontaneous synchronization of coupled circadian oscillators.
A dynamical model for the coupling of a population of circadian oscillators in the SCN is presented and experimentally testable predictions are that phases of individual cells are governed by their intrinsic periods and efficient synchronization is achieved when the average neurotransmitter concentration would dampen individual oscillators.
Differential effects of PER2 phosphorylation: molecular basis for the human familial advanced sleep phase syndrome (FASPS).
Interference with specific aspects of mPER2 phosphorylation leads to either short or long periods in oscillating fibroblasts, which explains not only the FASPS phenotype, but also the effect of the tau mutation in hamster as well as the doubletime mutants (dbtS and dbtL ) in Drosophila.
Modeling feedback loops of the Mammalian circadian oscillator.
A mathematical model that reflects the essential features of the mammalian circadian oscillator to characterize the differential roles of negative and positive feedback loops is presented and leads to a testable prediction of a molecular and behavioral phenotype: circadian oscillations should be rescued when arrhythmic Per2Brdm1 mutant mice are crossed with Rev- erbalpha -/- mutant mice.
Coupling governs entrainment range of circadian clocks
- U. Abraham, A. Granada, P. Westermark, Markus Heine, A. Kramer, H. Herzel
- PsychologyMolecular Systems Biology
- 30 November 2010
Differences between master and the peripheral clocks suggest that coupling‐induced rigidity in the SCN filters environmental noise to create a robust circadian system.
Biological profiling of gene groups utilizing Gene Ontology.
- N. Blüthgen, K. Brand, Branka Čajavec, M. Swat, H. Herzel, D. Beule
- BiologyGenome informatics. International Conference on…
- 26 July 2004
This work presents a statistical framework that tests whether functions, processes or locations described in the Gene Ontology are significantly enriched within a group of interesting genes when compared to a reference group and analyzes the robustness of the framework with respect to the exact gene group composition.
Bifurcation analysis of the regulatory modules of the mammalian G1/S transition
It is shown that the positive feedback regulation of E2F1 and a double activator-inhibitor module can lead to bistability and core modules can explain major features of the complex G1/S network and have a robust decision taking function.
Chaotic Evolution and Strange Attractors
- H. Herzel
In this 17th volume of the "Springer Series in Surface Sciences" the editors publish the 10 lectures, given on the third workshop on interface phenomena at the Dalhousie University. The topic was…