Hysteresis in one-dimensional reaction-diffusion systems

We introduce a simple nonequilibrium model for a driven diffusive system with nonconservative reaction kinetics which exhibits ergodicity breaking and hysteresis in one dimension. These phenomena can be understood through a description of the dominant stochastic many-body dynamics in terms of an equilibrium single-particle problem, viz. the random motion of a shock in an effective potential. This picture also leads to the exact phase diagram of the system and suggests a new generic mechanism for "freezing by heating".Comment: 4 Pages, 5 figure

Superradiance-like Electron Transport through a Quantum Dot

We theoretically show that intriguing features of coherent many-body physics can be observed in electron transport through a quantum dot (QD). We first derive a master equation based framework for electron transport in the Coulomb-blockade regime which includes hyperfine (HF) interaction with the nuclear spin ensemble in the QD. This general tool is then used to study the leakage current through a single QD in a transport setting. We find that, for an initially polarized nuclear system, the proposed setup leads to a strong current peak, in close analogy with superradiant emission of photons from atomic ensembles. This effect could be observed with realistic experimental parameters and would provide clear evidence of coherent HF dynamics of nuclear spin ensembles in QDs.Comment: 21 pages, 10 figure

Structural features of tight-junction proteins

Tight junctions are complex supramolecular entities composed of integral membrane proteins, membrane-associated and soluble cytoplasmic proteins engaging in an intricate and dynamic system of protein-protein interactions. Three-dimensional structures of several tight-junction proteins or their isolated domains have been determined by X-ray crystallography, nuclear magnetic resonance spectroscopy, and cryo-electron microscopy. These structures provide direct insight into molecular interactions that contribute to the formation, integrity, or function of tight junctions. In addition, the known experimental structures have allowed the modeling of ligand-binding events involving tight-junction proteins. Here, we review the published structures of tight-junction proteins. We show that these proteins are composed of a limited set of structural motifs and highlight common types of interactions between tight-junction proteins and their ligands involving these motifs

Structured Finance Influence on Financial Market Stability – Evaluation of Current Regulatory Developments

In 2007 the world faced one of the biggest financial crises ever. It was the third important financial crisis in the last 12 years. Spillovers to the real economy and moral hazard behaviour of carpetbaggers resulted in enormous pressure on worldwide political institutions to approve a more rigorous regulation on financial institutions and predict financial crises via early warning systems. We analyzed the performance of structured finance ratings and structured finance issuance/outstanding to detect the main shortcomings of the subprime crisis. Afterwards we explain the behaviour of market participants with theoretical models and a survey of institutions involved in securitization. With the conclusions of this analysis we evaluate the EU regulation on credit rating agencies and current Basel II enhancements. Finally we can determine that most regulatory enhancements are in accordance with our analyzed shortcomings. Some approaches like the introduction of a leverage ratio are counterproductive and a danger for worldwide economic growth.structured finance, ratings, regulation, subprime crisis, Basel II, leverage ratio

Quantum correlations of light due to a room temperature mechanical oscillator for force metrology

The coupling of laser light to a mechanical oscillator via radiation pressure leads to the emergence of quantum mechanical correlations between the amplitude and phase quadrature of the laser beam. These correlations form a generic non-classical resource which can be employed for quantum-enhanced force metrology, and give rise to ponderomotive squeezing in the limit of strong correlations. To date, this resource has only been observed in a handful of cryogenic cavity optomechanical experiments. Here, we demonstrate the ability to efficiently resolve optomechanical quantum correlations imprinted on an optical laser field interacting with a room temperature nanomechanical oscillator. Direct measurement of the optical field in a detuned homodyne detector ("variational measurement") at frequencies far from the resonance frequency of the oscillator reveal quantum correlations at the few percent level. We demonstrate how the absolute visibility of these correlations can be used for a quantum-enhanced estimation of the quantum back-action force acting on the oscillator, and provides for an enhancement in the relative signal-to-noise ratio for the estimation of an off-resonant external force, even at room temperature

Hybrid Architecture for Engineering Magnonic Quantum Networks

We show theoretically that a network of superconducting loops and magnetic particles can be used to implement magnonic crystals with tunable magnonic band structures. In our approach, the loops mediate interactions between the particles and allow magnetic excitations to tunnel over long distances. As a result, different arrangements of loops and particles allow one to engineer the band structure for the magnonic excitations. Furthermore, we show how magnons in such crystals can serve as a quantum bus for long-distance magnetic coupling of spin qubits. The qubits are coupled to the magnets in the network by their local magnetic-dipole interaction and provide an integrated way to measure the state of the magnonic quantum network.Comment: Manuscript: 4 pages, 3 figures. Supplemental Material: 9 pages, 4 figures. V2: Published version in PRA: 14 pages + 8 figures. Substantial rearrangement of the content of the previous versio

Serum procalcitonin for discrimination of blood contamination from bloodstream infection due to coagulase-negative staphylococci

The diagnostic value of serum procalcitonin (PCT) to distinguish blood contamination from bloodstream infection (BSI) due to coagulase-negative staphylococci was evaluated. Patients with BSI had higher PCT concentration than those with blood contamination at day -1, day 0 and day +1 with regard to blood culture collection (p > 0.05), whereas serum C-reactive protein values were significantly higher only on day +1. At a cutoff of 0.1 ng/dl, PCT had a sensitivity of 86% and 100%, and a specificity of 60% and 80% for the diagnosis of BSI on day -1 and 0, respectively. In addition to clinical and microbiological parameters, PCT may help discriminating blood contamination from BSI due coagulase-negative staphylococci

Serum Procalcitonin for Discrimination of Blood Contamination from Bloodstream Infection due to Coagulase-Negative Staphylococci

Abstract : The diagnostic value of serum procalcitonin (PCT) to distinguish blood contamination from bloodstream infection (BSI) due to coagulase-negative staphylococci was evaluated. Patients with BSI had higher PCT concentration than those with blood contamination at day -1, day 0 and day +1 with regard to blood culture collection (p < 0.05), whereas serum C-reactive protein values were significantly higher only on day +1. At a cutoff of 0.1 ng/dl, PCT had a sensitivity of 86% and 100%, and a specificity of 60% and 80% for the diagnosis of BSI on day -1 and 0, respectively. In addition to clinical and microbiological parameters, PCT may help discriminating blood contamination from BSI due coagulase-negative staphylococc