L. Caputo | Searcharxiv

arXiv2018

On the square root of the inverse different

Let N/F be a finite, normal extension of number fields with Galois group G. Suppose that N/F is weakly ramified, and that the square root A(N/F) of the inverse different of N.F is defined. (This latter condition holds if, for example, G is of odd order.) B. Erez has conjectured that the class (A(N/F)) of A(N/F) in the locally free class group Cl(ZG) of ZG is equal to the Cassou-Nogues-Frohlich root number class W(N/F) attached to N/F. We establish a precise formula for (A(N/F)) - W(N/F) in terms of the signs of certain symplectic Galois-Gauss sums whenever N/F is tame and (A(N/F)) is defined. We thereby show that, in general, (A(N/F)) is not equal to W(N/F).

math.NT↗

arXiv2005

On Myosin II dynamics in the presence of external loads

We address the controversial hot question concerning the validity of the loose coupling versus the lever-arm theories in the actomyosin dynamics by re-interpreting and extending the phenomenological washboard potential model proposed by some of us in a previous paper. In this new model a Brownian motion harnessing thermal energy is assumed to co-exist with the deterministic swing of the lever-arm, to yield an excellent fit of the set of data obtained by some of us on the sliding of Myosin II heads on immobilized actin filaments under various load conditions. Our theoretical arguments are complemented by accurate numerical simulations, and the robustness of the model is tested via different choices of parameters and potential profiles.

q-bio.SC↗

arXiv2004

A Phenomenological model of Myosin II dynamics in the presence of external loads

We address the controversial hot question concerning the validity of the loose coupling versus the lever-arm theories in the actomyosin dynamics by re-interpreting and extending the phenomenological washboard potential model proposed by some of us in a previous paper. In this new model a Brownian motion harnessing thermal energy is assumed to co-exist with the deterministic swing of the lever-arm, to yield an excellent fit of the set of data obtained by some of us on the sliding of Myosin II heads on immobilized actin filaments under various load conditions. Our theoretical arguments are complemented by accurate numerical simulations, and the robustness of the model is tested via different choices of parameters and potential profiles.

q-bio.BM↗

arXiv2004

Lever-arm and Washboard-potential theories jointly account for Myosin II dynamics

We address the controversial hot question concerning the validity of the loose-coupling versus the lever-arm models in the actomyosin dynamics by re-interpreting and extending the washboard potential model proposed by some of us in a previous paper. In the new theory, a loose-coupling mechanism co-exists with the deterministic lever-arm model. The synergetic action of a random component, originating from the harnessed thermal energy, and of the power-stroke generated by the lever-arm classical mechanism is seen to yield an excellent fit of the set of data obtained in T. Yanagida's laboratory on the sliding of Myosin II heads on actin filaments under various load conditions. Our theoretical arguments are complemented by accurate numerical simulations, and the robustness of theory is tested via different combination of parameters and potential profiles.

q-bio.BM↗