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Séminaire

Jeudi 22 Juin 2017
De 14h à 15h
Centre de Recherche - Paris

Taking the temperature of rotating magnetotactic bacteria: A test of the fluctuation-dissipation theorem for living cells

Magnetotactic bacteria provide a unique opportunity to test the applicability of statistical mechanics to living systems. Due to the presence of a unique organelle, the magnetosome, these cells possess a magnetic moment, and therefore a tendency to align with external magnetic fields. However, this alignment is never perfect because of both thermal and non-thermal noise. By performing single-cell tracking experiments, we “take the temperature” of each individual cell, that is we measure the level of noise, in two different ways: from the cells' distribution of orientations (a quantity depending only on fluctuations) and from their rotational diffusion coefficient (a quantity depending both on fluctuations and dissipation). These two independent evaluations are in agreement, and return an elevated value for the cells’ effective temperature. The rotation of flagellated bacteria is therefore greatly influenced by biological noise, and yet our results suggest that it can be well described by a modified fluctuation-dissipation theorem.

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Orateur(s)

Pr Cécile FRADIN
Assistant Professor

McMaster University, Hamilton, Canada

Invité(e)(s) par

Dr Nathalie Dostatni
Domain 2 - UMR 3664 - Nuclear Dynamics

Institut Curie

Contact

©DR

Pr Cécile FRADIN

Assistant Professor

McMaster University, Hamilton, Canada

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Dr Nathalie Dostatni

Institut Curie

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