The bacterium Geobacter sulfurreducens requires the expression of conductive protein filaments or pili to respire extracellular electron acceptors such as iron oxides and uranium and to wire electroactive biofilms, but the contribution of the protein fiber to charge transport has remained elusive. Here we demonstrate efficient long-range charge transport along individual pili purified free of m...

We explore Random Scale-Free networks of populations, modelled by chaotic Ricker maps, connected by transport that is triggered when population density in a patch is in excess of a critical threshold level. Our central result is that threshold-activated dispersal leads to stable fixed populations, for a wide range of threshold levels. Further, suppression of chaos is facilitated when the thresh...

We have studied electron transport through single redox molecules, perylene tetracarboxylic diimides, covalently bound to two gold electrodes via different linker groups, as a function of electrochemical gate voltage and temperature in different solvents. The conductance of these molecules is sensitive to the linker groups because of different electronic coupling strengths between the molecules...

Microbial biofilms grown utilizing electrodes as metabolic electron acceptors or donors are a new class of biomaterials with distinct electronic properties. Here we report that electron transport through living electrode-grown Geobacter sulfurreducens biofilms is a thermally activated process with incoherent redox conductivity. The temperature dependency of this process is consistent with elect...

Strontium titanate (SrTiO3, STO) is a critically important material for the study of emergent electronic phases in complex oxides, as well as for the development of applications based on their heterostructures. Despite the large body of knowledge on STO, there are still many uncertainties regarding the role of defects in the properties of STO, including their influence on ferroelectricity in bu...

We analyze the transport properties of bilayer quantum Hall systems at total filling factor nu=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered sy...

Protein kinase D (PKD) binds to a pool of diacylglycerol (DAG) in the TGN and undergoes a process of activation that involves heterotrimeric GTP-binding protein subunits betagamma to regulate membrane fission. This fission reaction is used to generate transport carriers at the TGN that are en route to the cell surface. We now report that PKD is activated specifically by G protein subunit beta1g...

The AMP-activated protein kinase (AMPK) is an energy-sensing enzyme that is activated during exercise and muscle contraction as a result of acute decreases in ATP:AMP and phosphocreatine:creatine. Physical exercise increases muscle glucose uptake, enhances insulin sensitivity and leads to fatty acid oxidation in muscle. An important issue in muscle biology is to understand whether AMPK plays a ...

Following laser activation of electron transport in the pale green mutant of Chlamydomonas reinhardii, the following kinetics are observed: 1) A rapid absorption decrease at 421 mmu (half-time < 2 x 10(-6) sec) recovering with a half-time of approximately 7 x 10(-3) sec. 2) Oxidation of cytochrome f at 554 mmu with a half-time of 1 x 10(-4) sec. 3) Oxidation of cytochrome of type b, at 432 and ...

The intestinal Ca(2+) transport protein CaT1 has recently been shown to have the biophysical characteristics of the Ca(2+)-release activated Ca(2+) channel that refills internal Ca(2+) stores following agonist-elicited release. This finding highlights a hitherto unrecognized link between epithelial Ca(2+) transport and Ca(2+) signalling.