Piecewise linearity in the GWGW approximation for accurate quasiparticle energy predictions

We identify the deviation from the straight line error (DSLE) -- i.e., the spurious non-linearity of the total energy as a function of fractional particle number -- as the main source for the discrepancy between experimental vertical ionization energies and theoretical quasiparticle energies, as obtained from the $GW$ and $GW$+SOSEX approximations to many-body perturbation theory (MBPT). For self-consistent calculations, we show that $GW$ suffers from a small DSLE. Conversely, for perturbative $G_0W_0$ and $G_0W_0$+SOSEX calculations the DSLE depends on the starting point. We exploit this starting-point dependence to reduce (or completely eliminate) the DSLE. We find that the agreement with experiment increases as the DSLE reduces. DSLE-minimized schemes, thus, emerge as promising avenues for future developments in MBPT

How taking a bit longer to do your shopping might save you money

To what extent can shoppers convert the time they spend looking for particular products into monetary savings? Using electronic tags to study the behavior of 12,000 consumers in a large supermarket in Northern California, Fabio Pinna and Stephan Seiler find that consumers can save up to $11 per shopping trip just by searching longer for products

Consumer search: evidence from path-tracking data

We estimate the effect of consumer search on the price of the purchased product in a physical store environment. We implement the analysis using a unique data set obtained from radio frequency identification tags, which are attached to supermarket shopping carts. This technology allows us to record consumers' purchases as well as the time they spent in front of the shelf when contemplating which product to buy, giving us a direct measure of search effort. Controlling for a host of confounding factors, we estimate that an additional minute spent searching lowers price paid by $2.10 which represents 8 percent of average trip-level expenditure

Deep Neural Network Equalization for Optical Short Reach Communication

Nonlinear distortion has always been a challenge for optical communication due to the nonlinear transfer characteristics of the fiber itself. The next frontier for optical communication is a second type of nonlinearities, which results from optical and electrical components. They become the dominant nonlinearity for shorter reaches. The highest data rates cannot be achieved without effective compensation. A classical countermeasure is receiver-side equalization of nonlinear impairments and memory effects using Volterra series. However, such Volterra equalizers are architecturally complex and their parametrization can be numerical unstable. This contribution proposes an alternative nonlinear equalizer architecture based on machine learning. Its performance is evaluated experimentally on coherent 88 Gbaud dual polarization 16QAM 600 Gb/s back-to-back measurements. The proposed equalizers outperform Volterra and memory polynomial Volterra equalizers up to 6th orders at a target bit-error rate (BER) of 10 −2 by 0.5 dB and 0.8 dB in optical signal-to-noise ratio (OSNR), respectively

Cytochrome P450 Enzymes Involved in Metoprolol Metabolism and Use of Metoprolol as a CYP2D6 Phenotyping Probe Drug

Metoprolol is used for phenotyping of cytochrome P450 (CYP) 2D6, a CYP isoform considered not to be inducible by inducers of the CYP2C, CYP2B, and CYP3A families such as rifampicin. While assessing CYP2D6 activity under basal conditions and after pre-treatment with rifampicin in vivo, we surprisingly observed a drop in the metoprolol/α-OH-metoprolol clearance ratio, suggesting CYP2D6 induction. To study this problem, we performed in vitro investigations using HepaRG cells and primary human hepatocytes (before and after treatment with 20 μM rifampicin), human liver microsomes, and CYP3A4-overexpressing supersomes. While mRNA expression levels of CYP3A4 showed a 15- to 30-fold increase in both cell models, mRNA of CYP2D6 was not affected by rifampicin. 1′-OH-midazolam formation (reflecting CYP3A4 activity) increased by a factor of 5–8 in both cell models, while the formation of α-OH-metoprolol increased by a factor of 6 in HepaRG cells and of 1.4 in primary human hepatocytes. Inhibition studies using human liver microsomes showed that CYP3A4, 2B6, and 2C9 together contributed 19.0 ± 2.6% (mean ± 95%CI) to O-demethylation, 4.0 ± 0.7% to α-hydroxylation, and 7.6 ± 1.7% to N-dealkylation of metoprolol. In supersomes overexpressing CYP3A4, metoprolol was α-hydroxylated in a reaction inhibited by the CYP3A4-specific inhibitor ketoconazole, but not by the CYP2D6-specific inhibitor quinidine. We conclude that metoprolol is not exclusively metabolized by CYP2D6. CYP3A4, 2B6, and 2C9, which are inducible by rifampicin, contribute to α-hydroxylation, O-demethylation, and N-dealkylation of metoprolol. This contribution is larger after CYP induction by rifampicin but is too small to compromise the usability of metoprolol α-hydroxylation for CYP2D6 phenotyping

A Scoping Review on the Therapeutic Potential of Resin From the Species Larix decidua Mill. [Pinaceae] to Treat Ulcerating Wounds.

Malignant ulcerating wounds or neoplastic lesions are a considerable burden for patients suffering from advanced cancer. These wounds have no effective treatment and are very difficult to manage. The present review summarizes evidence in support of a hypothesis put forward in anthroposophic medicine, which suggests a beneficial role of resin from the species Larix decidua Mill. [Pinaceae] for treating such wounds. A systematic search strategy was performed using the databases PubMed, EMBASE and SciFinder. The included publications described the chemical composition of this species, as well as in vitro, in vivo, and ex vivo experiments using plant extracts and isolated compounds. The results show that among the phytochemical classes, terpenoids were the major components of this species, especially in the resin. The summarized biological experiments revealed antimicrobial, antioxidant and anti-inflammatory effects, with promising potential for the extracts and isolated compounds. However, the molecular mechanisms and toxicological effects are as of yet not conclusively evaluated. From the data of our study, we can conclude that L. decidua might indeed have a promising potential for the treatment of malignant wounds, but definitive information that can prove its effectiveness is still lacking. We therefore suggest that future efforts should be dedicated to the evaluation of L. decidua resin's therapeutic use considering its antiseptic action and proposed wound healing properties

On perishability and Vertical Price Transmission: empirical evidences from Italy

Studies on the causes for asymmetries in vertical price transmission date back to decades ago, but the attention of theorists and empirical economists is still vivid. In particular the role of perishability is not fully defined. We investigate the vertical price transmission for a heterogeneous group of fruits and vegetables that differ for their degree of perishability. The error correction model we estimate allows to conclude that asymmetries in vertical price transmission tend to vanish for perishable products

On Perishability and Vertical Price Transmission: empirical evidences from Italy

Studies on the causes for asymmetries in vertical price transmission date back to decades ago, but the attention of theorists and empirical economists is still vivid. In particular the role of perishability is not fully defined. We investigate the vertical price transmission for a heterogeneous group of fruits and vegetables that differ for their degree of perishability. The error correction model we estimate allows toconclude that asymmetries in vertical price transmission tend to vanish for perishable products

The Fate of the Merger Remnant in GW170817 and its Imprint on the Jet Structure

The first neutron star binary merger detected in gravitational waves, GW170817 and the subsequent detection of its emission across the electromagnetic spectrum showed that these systems are viable progenitors of short $\gamma$-ray bursts (sGRB). The afterglow signal of GW170817 has been found to be consistent with a structured GRB jet seen off-axis, requiring significant amounts of relativistic material at large angles. This trait can be attributed to the interaction of the relativistic jet with the external wind medium. Here we perform numerical simulations of relativistic jets interacting with realistic wind environments in order to explore how the properties of the wind and central engine affect the structure of successful jets. We find that the angular energy distribution of the jet depends primarily on the ratio between the lifetime of the jet and the time it takes the merger remnant to collapse. We make use of these simulations to constrain the time it took for the merger remnant in GW170817 to collapse into a black hole based on the angular structure of the jet as inferred from afterglow observations. We conclude that the lifetime of the merger remnant in GW170817 was $\approx 1-1.7$s, which, after collapse, triggered the formation of the jet.Comment: 13 figures, 15 pages, accepted in Ap