Selective Uncoupling of Individual Mitochondria within a Cell Using a Mitochondria-Targeted Photoactivated Protonophore

Depolarization of an individual mitochondrion or small clusters of mitochondria within cells has been achieved using a photoactivatable probe. The probe is targeted to the matrix of the mitochondrion by an alkyltriphenylphosphonium lipophilic cation and releases the protonophore 2,4-dinitrophenol locally in predetermined regions in response to directed irradiation with UV light via a local photolysis system. This also provides a proof of principle for the general temporally and spatially controlled release of bioactive molecules, pharmacophores, or toxins to mitochondria with tissue, cell, or mitochondrion specificity

Production of Cultural Policy in Russia : Authority and Intellectual Leadership

The paper discusses different frameworks of knowledge production within the discourses and practices of Russian cultural policy. Russian cultural policy as an administrative sector has been developed in line with two distinctive governmental regimes, more precisely during the period of liberal decentralisation of the 1990s and the conservative centralisation from 2011 up until today. The study focuses on the main changes that have occurred in the framework of policy design and participation in policy-making. An attempt is made to combine Foucauldian analytical frameworks of power and discourse with a Gramscian hegemonic approach to political studies that was mainly advocated by the Essex scholars—Ernesto Laclau, Chantal Mouffe and David Howarth. Such a perspective opens up a possibility of considering the institutional rearrangements of intellectual leadership through which the post-2012 establishment has endeavoured to advance its sovereignty and planning capacities in both the symbolic and normative dimension of culture. Thus examined, Russian state cultural policy turns out to be intrinsically subordinated to the sovereignty of the presidential apparatus that privileges the conservative stance of the ‘Russian World’ project and neglects human rights and cultural diversity.peerReviewe

Asymptotic analysis and analytical solutions of a model of cardiac excitation

We describe an asymptotic approach to gated ionic models of single-cell cardiac excitability. It has a form essentially different from the Tikhonov fast-slow form assumed in standard asymptotic reductions of excitable systems. This is of interest since the standard approaches have been previously found inadequate to describe phenomena such as the dissipation of cardiac wave fronts and the shape of action potential at repolarization. The proposed asymptotic description overcomes these deficiencies by allowing, among other non-Tikhonov features, that a dynamical variable may change its character from fast to slow within a single solution. The general asymptotic approach is best demonstrated on an example which should be both simple and generic. The classical model of Purkinje fibers (Noble in J. Physiol. 160:317–352, 1962) has the simplest functional form of all cardiac models but according to the current understanding it assigns a physiologically incorrect role to the Na current. This leads us to suggest an “Archetypal Model” with the simplicity of the Noble model but with a structure more typical to contemporary cardiac models. We demonstrate that the Archetypal Model admits a complete asymptotic solution in quadratures. To validate our asymptotic approach, we proceed to consider an exactly solvable “caricature” of the Archetypal Model and demonstrate that the asymptotic of its exact solution coincides with the solutions obtained by substituting the “caricature” right-hand sides into the asymptotic solution of the generic Archetypal Model. This is necessary, because, unlike in standard asymptotic descriptions, no general results exist which can guarantee the proximity of the non-Tikhonov asymptotic solutions to the solutions of the corresponding detailed ionic model