Etude de la contagion sur les marchés actions

Ce travail a pour but de mettre en évidence la nécessité de l’analyse en continu des coefficients de corrélation dans le but de prévenir le risque systémique. Dans un premier temps, on verra les fondements théoriques qui ont articulé la réflexion constituant la genèse de ce travail. Dans un deuxième temps, grâce à deux exemples, on verra comment l’étude des co-mouvements peut permettre d’observer l’effet de contagion sur les marchés actions. Finalement, des potentielles applications de l’analyse des coefficients de corrélation seront mises en avant. Par cette démarche, on constatera que l’observation des mouvements joints par le biais de l’analyse technique, peut permettre de déceler des opportunités d’investissements

Transient tether between the SRP RNA and SRP receptor ensures efficient cargo delivery during cotranslational protein targeting

Kinetic control of macromolecular interactions plays key roles in biological regulation. An example of such control occurs in cotranslational protein targeting by the signal recognition particle (SRP), during which the SRP RNA and the cargo both accelerate complex assembly between the SRP and SRP receptor FtsY 10^2-fold. The molecular mechanism underlying these rate accelerations was unclear. Here we show that a highly conserved basic residue, Lys399, on the lateral surface of FtsY provides a novel RNA tetraloop receptor to mediate the SRP RNA- and cargo-induced acceleration of SRP–FtsY complex assembly. We propose that the SRP RNA, by using its tetraloop to interact with FtsY–Lys399, provides a transient tether to stabilize the early stage and transition state of complex formation; this accelerates the assembly of a stable SRP–FtsY complex and allows the loading of cargo to be efficiently coupled to its membrane delivery. The use of a transient tether to increase the lifetime of collisional intermediates and reduce the dimension of diffusional search represents a novel and effective mechanism to accelerate macromolecular interactions