Nonlocal Andreev reflection, fractional charge and current-phase relation in topological bilayer exciton condensate junctions

We study Andreev reflection and Josephson currents in topological bilayer exciton condensates (TEC). These systems can create 100% spin entangled nonlocal currents with high amplitudes due to perfect nonlocal Andreev reflection. This Andreev reflection process can be gate tuned from a regime of purely retro reflection to purely specular reflection. We have studied the bound states in TEC-TI-TEC Josephson junctions and find a gapless dispersion for perpendicular incidence. The presence of a sharp transition in the supercurrent-phase relationship when the system is in equilibrium is a signature of fractional charge, which can be further revealed in ac measurements faster than relaxation processes via Landau-Zener processes.Comment: Submitted to Physical Review

Translational and rotational motions of albumin sensed by a non-covalent associated porphyrin under physiological and acidic conditions: a fluorescence correlation spectroscopy and time resolved anisotropy study.

The interaction between a free-base, anionic water-soluble porphyrin, TSPP, and the drug carrier protein, bovine serum albumin (BSA) has been studied by time-resolved fluorescence anisotropy (TRFA) and fluorescence correlation spectroscopy (FCS) at two different pH-values. Both rotational correlation times and translational diffusion times of the fluorescent species indicate that TSPP binding to albumin induces very little conformational changes in the protein under physiological conditions. By contrast, at low pH, a bi-exponential decay is obtained where a short rotational correlation time (¿ int¿=¿1.2 ns) is obtained, which is likely associated to wobbling movement of the porphyrin in the protein binding site. These physical changes are corroborated by circular dichroism (CD) data which show a 37% loss in the protein helicity upon acidification of the medium. In the presence of excess porphyrin formation of porphyrin J-aggregates is induced, which can be detected by time-resolved fluorescence with short characteristic times. This is also reflected in FCS data by an increase in molecular brightness together with a decrease in the number of fluorescent molecules passing through the detection volume of the sampl

Mean Reversion in International Stock Markets: An Empirical Analysis of the 20th Century

This paper analyzes mean reversion in international stock markets during the period 1900-2008, using annual data. Our panel of stock indexes in seventeen developed countries, covering a time span of more than a century, allows us to analyze in detail the dynamics of the mean-reversion process. In the period 1900-2008 it takes stock prices about 13.8 years, on average, to absorb half of a shock. However, using a rolling-window approach we establish large fluctuations in the speed of mean reversion over time. The highest mean reversion speed is found for the period including the Great Depression and the start of World War II. Furthermore, the early years of the Cold War and the period covering the Oil Crisis of 1973, the Energy Crisis of 1979 and Black Monday in 1987 are also characterized by relatively fast mean reversion. Overall, we document half-lives ranging from a minimum of 2.1 years to a maximum of 23.8 years. In a substantial number of time periods no significant mean reversion is found at all, which underlines the fact that the choice of data sample contributes substantially to the evidence in favor of mean reversion. Our results suggest that the speed at which stocks revert to their fundamental value is higher in periods of high economic uncertainty, caused by major economic and political events.mean reversion, market efficiency

Foreign Sovereign Immunity and Saudi Arabia v. Nelson: A Practical Guide

In any federal judicial proceeding in the United States involving a foreign government or an entity controlled by a foreign government, it is vital to first determine whether that government or entity will be afforded immunity from prosecution under the doctrine of sovereign immunity. If the government or entity qualifies for immunity, they must waive their immunity for the court to have jurisdiction over them. Prior to 1976, there was considerable turmoil within the United States government over how to distinguish those entities that qualified for immunity from those that did not. Congress responded to this turmoil with the passage of the Foreign Sovereign Immunities Act of 1976. This Act purported to be the final word on this subject and has since been universally applied by federal courts. Unfortunately, a lack of clear definitions for certain key terms has resulted in a wide variety of interpretations and inconsistent results. This Note examines the most recent interpretation of the Foreign Sovereign Immunities Act by the United States Supreme Court. In many ways, Saudi Arabia v. Nelson represents a significant departure by the Supreme Court from its prior rulings on foreign sovereign immunity. This Note attempts to spotlight those departures and provide insights into why the Court ruled the way it did

Metabolic reprogramming of murine cardiomyocytes during autophagy requires the extracellular nutrient sensor decorin.

The extracellular matrix is a master regulator of tissue homeostasis in health and disease. Here we examined how the small, leucine-rich, extracellular matrix proteoglycan decorin regulates cardiomyocyte metabolism during fasting in vivo. First, we validated in Dcn-/- mice that decorin plays an essential role in autophagy induced by fasting. High-Throughput metabolomics analyses of cardiac tissue in Dcn-/- mice subjected to fasting revealed striking differences in the hexosamine biosynthetic pathway resulting in aberrant cardiac O-β-N-Acetylglycosylation as compared with WT mice. Functionally, Dcn-/- mice maintained cardiac function at a level comparable with nonfasted animals whereas fasted WT mice showed reduced ejection fraction. Collectively, our results suggest that reduced sensing of nutrient deprivation in the absence of decorin preempts functional adjustments of cardiac output associated with metabolic reprogramming. © 2018 Gubbiotti et al

A Common Origin for Quasar Extended Emission-Line Regions and Their Broad-Line Regions

We present a correlation between the presence of luminous extended emission-line regions (EELRs) and the metallicity of the broad-line regions (BLRs) of low-redshift quasars. The result is based on ground-based [O III] 5007 narrow-band imaging and Hubble Space Telescope UV spectra of 12 quasars at 0.20 < z < 0.45. Quasars showing luminous EELRs have low-metallicity BLRs (Z < 0.6 Z_Solar), while the remaining quasars show typical metal-rich gas (Z > Z_Solar). Previous studies have shown that EELRs themselves also have low metallicities (Z < 0.5 Z_Solar). The correlation between the occurrence of EELRs and the metallicity of the BLRs, strengthened by the sub-Solar metallicity in both regions, indicates a common external origin for the gas, almost certainly from the merger of a gas-rich galaxy. Our results provide the first direct observational evidence that the gas from a merger can indeed be driven down to the immediate vicinity (< 1 pc) of the central black hole.Comment: Accepted for publication in ApJ Letters. 4 pages, 1 figure, 1 tabl

Investigation of Hamamatsu H8500 phototubes as single photon detectors

We have investigated the response of a significant sample of Hamamatsu H8500 MultiAnode PhotoMultiplier Tubes (MAPMTs) as single photon detectors, in view of their use in a ring imaging Cherenkov counter for the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. For this, a laser working at 407.2nm wavelength was employed. The sample is divided equally into standard window type, with a spectral response in the visible light region, and UV-enhanced window type MAPMTs. The studies confirm the suitability of these MAPMTs for single photon detection in such a Cherenkov imaging application