Raphael Cerf

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We pursue the task of developing a finite population counterpart to Eigen’s model. We consider the classical Wright–Fisher model describing the evolution of a population of size m of chromosomes of length l over an alphabet of cardinality κ. The mutation probability per locus is q. The replication rate is σ > 1 for the master sequence and 1 for the other(More)
The structural fluctuations specific to self-assemblies of biological molecules have been investigated further with ultrasonic techniques by using frog virus 3 (FV3). We compared the ultrasonic properties of complete FV3 virions and of several subparticles that may be obtained from this DNA virus: (i) the central nucleoprotein core versus its component DNA(More)
When the coat protein of the small icosahedral virus, brome mosaic virus, reassembles into capsids, the ultrasonic absorption of the solution greatly increases. Submitting the solution to an ultrasonic field thus appears to reveal spontaneous molecular motions within a protein assembly. Confirmatory evidence of a dynamics of a protein shell comes from(More)
The structural fluctuations specific to self-assembled biological systems have been investigated further with ultrasonic techniques by using two strains of tobacco mosaic virus (TMV), as well as the helical aggregate of the common strain protein and subassemblies of it. We confirmed our earlier conclusion that protein assemblies exhibit specific structural(More)
The thermal stability of virions present in purified suspensions of three tymoviruses, turnip yellow mosaic virus (TYMV), belladonna mottle virus (BelMV) and eggplant mosaic virus (EMV) was investigated by microcalorimetry. Virions are less stable than natural empty shells at 4.5 < or = pH < or = 8.5. Polyvalent cations present in TYMV stabilize the virions(More)
The thermal denaturation of the common strain of a rod-shaped plant virus, tobacco mosaic virus, has been investigated by differential scanning calorimetry, and compared to that of various aggregation states of its coat protein and to that of three other TMV strains. The state of the virions was monitored by electron microscopy and analytical(More)
Ultrasonic and calorimetric studies of small homogenously-sized DMPC unilamellar vesicles showed two thermal transitions at temperatures T c1 and T c2 (T c2 ≥T c1 ); T c2 is close to the phase transition temperature, T c , of large vesicles. The process at T c2 is not a fusion of vesicles and is interpreted as characterizing an order-disorder transition(More)