A Dynamical Theory of Electron Transfer: Crossover from Weak to Strong Electronic Coupling

We present a real-time path integral theory for the rate of electron transfer reactions. Using graph theoretic techniques, the dynamics is expressed in a formally exact way as a set of integral equations. With a simple approximation for the self-energy, the rate can then be computed analytically to all orders in the electronic coupling matrix element. We present results for the crossover region between weak (nonadiabatic) and strong (adiabatic) electronic coupling and show that this theory provides a rigorous justification for the salient features of the rate expected within conventional electron transfer theory. Nonetheless, we find distinct characteristics of quantum behavior even in the strongly adiabatic limit where classical rate theory is conventionally thought to be applicable. To our knowledge, this theory is the first systematic dynamical treatment of the full crossover region.Comment: 11 pages, LaTeX, 8 Postscript figures to be published in J. Chem. Phy

Culture moderates biases in search decisions

Prior studies suggest that people often search insufficiently in sequential-search tasks compared with the predictions of benchmark optimal strategies that maximize expected payoff. However, those studies were mostly conducted in individualist Western cultures; Easterners from collectivist cultures, with their higher susceptibility to escalation of commitment induced by sunk search costs, could exhibit a reversal of this undersearch bias by searching more than optimally, but only when search costs are high. We tested our theory in four experiments. In our pilot experiment, participants generally undersearched when search cost was low, but only Eastern participants oversearched when search cost was high. In Experiments 1 and 2, we obtained evidence for our hypothesized effects via a cultural-priming manipulation on bicultural participants in which we manipulated the language used in the program interface. We obtained further process evidence for our theory in Experiment 3, in which we made sunk costs nonsalient in the search task—as expected, cross-cultural effects were largely mitigated

Modified-gravity wormholes without exotic matter

A fundamental ingredient in wormhole physics is the flaring-out condition at the throat which, in classical general relativity, entails the violation of the null energy condition. In this work, we present the most general conditions in the context of modified gravity, in which the matter threading the wormhole throat satisfies all of the energy conditions, and it is the higher order curvature terms, which may be interpreted as a gravitational fluid, that support these nonstandard wormhole geometries. Thus, we explicitly show that wormhole geometries can be theoretically constructed without the presence of exotic matter, but are sustained in the context of modified gravity.Comment: 4 pages. V2: Slight change in title, discussion on the stability and references added; version to appear in PRD. V3: reference adde

Feasibility of T1rho MR imaging in identification of the epileptogenic zone in patients with mesial temporal lobe epilepsy

Poster PresentationPURPOSE: T1rho is sensitive to physiochemical exchange and early molecular changes. We aim to investigate the feasibility and utility of T1rho MR imaging in identification of epileptogenic zone in patient with mesial temporal lobe epilepsy (MTLE). METHODS: 7 patients (male 28.6%, female 71.4%; mean age of 36.29±8.77 yrs) with estab…published_or_final_versio

Viscous Bianchi type I universes in brane cosmology

We consider the dynamics of a viscous cosmological fluid in the generalized Randall-Sundrum model for an anisotropic, Bianchi type I brane. To describe the dissipative effects we use the Israel-Hiscock-Stewart full causal thermodynamic theory. By assuming that the matter on the brane obeys a linear barotropic equation of state, and the bulk viscous pressure has a power law dependence on the energy density, the general solution of the field equations can be obtained in an exact parametric form. The obtained solutions describe generally a non-inflationary brane world. In the large time limit the brane Universe isotropizes, ending in an isotropic and homogeneous state. The evolution of the temperature and of the comoving entropy of the Universe is also considered, and it is shown that due to the viscous dissipative processes a large amount of entropy is created in the early stages of evolution of the brane world.Comment: 13 pages, 5 figures, to appear in Class. Quantum Gra