Electricity generation by Geobacter sulfurreducens attached to gold electrodes

The versatility of gold for electrode manufacture suggests that it could be an ideal material for some microbial fuel cell applications. However, previous studies have suggested that microorganisms that readily transfer electrons to graphite do not transfer electrons to gold. Investigations with Geobacter sulfurreducens demonstrated that it could grow on gold anodes producing current nearly as effectively as with graphite anodes. Current production was associated with the development of G. sulfurreducens biofilms up to 40 microm thick. No current was produced if pilA, the gene for the structural protein of the conductive pili of G. sulfurreducens, was deleted. The finding that gold is a suitable anode material for microbial fuel cells offers expanded possibilities for the construction of microbial fuel cells and the electrochemical analysis of microbe-electrode interactions.     

Partly Divisible Probability Measures on Locally Compact Abelian Groups

A notion of admissible probability measures μ on a locally compact Abelian group (LCA ‐ group) G with connected dual group Ĝ = ℝ^d × 𝕋ⁿ is defined. To such a measure μ, a closed semigroup Λ(μ) ⊆ (0, ∞) can be associated, such that, for t ∈ Λ(μ), the Fourier transform to the power t, (μˆ)^t, is a characteristic function. We prove that the existence of roots for non admissible probability measures underlies some restrictions, which do not hold in the admissible case. As we show for the example ℤ₂, in the case of LCA ‐ groups with non connected dual group, there is no canonical definition of the set Λ(μ).     

Chern–Simons theory,Stokes’ theorem,and the Duflo map

We consider a novel derivation of the expectation values of holonomies in Chern–Simons theory, based on Stokes’ Theorem and the functional properties of the Chern–Simons action. It involves replacing the connection by certain functional derivatives under the path integral. It turns out that ordering choices have to be made in the process, and we demonstrate that, quite surprisingly, the Duflo isomorphism gives the right ordering, at least in the simple cases that we consider. In this way, we determine the expectation values of unknotted, but possibly linked, holonomy loops for SU(2) and SU(3), and sketch how the method may be applied to more complicated cases. Our manipulations of the path integral are formal but well motivated by a rigorous calculus of integration on spaces of generalized connections which has been developed in the context of loop quantum gravity.     

A Triviality Result in the AdS/CFT Correspondence for Euclidean Quantum Fields with Exponential Interaction

We consider scalar quantum fields with exponential interaction on Euclidean hyperbolic space ${\mathbb{H}^2}$ in two dimensions. Using decoupling inequalities for Neumann boundary conditions on a tessellation of ${\mathbb{H}^2}$ , we are able to show that the infra-red limit for the generating functional of the conformal boundary field becomes trivial.     

Representing Euclidean Quantum Fields as Scaling Limit of Particle Systems

We give a new representation of Euclidean quantum fields as scaling limits of systems of interacting, continuous, classical particles in the grand canonical ensemble.