Heterotic fluxes and supersymmetry

We show that the formal alpha' expansion for heterotic flux vacua is only sensible when flux quantization and the appearance of string scale cycles in the geometry are carefully taken into account. We summarize a number of properties of solutions with N=1 and N=2 space-time supersymmetry.Comment: 21 page

Population scale data reveals the antidepressant effects of ketamine and other therapeutics approved for non-psychiatric indications.

Current therapeutic approaches to depression fail for millions of patients due to lag in clinical response and non-adherence. Here we provide new support for the antidepressant effect of an anesthetic drug, ketamine, by Inverse-Frequency Analysis of eight million reports from the FDA Adverse Effect Reporting System. The results of the examination of population scale data revealed that patients who received ketamine had significantly lower frequency of reports of depression than patients who took any other combination of drugs for pain. The analysis also revealed that patients who took ketamine had significantly lower frequency of reports of pain and opioid induced side effects, implying ketamine's potential to act as a beneficial adjunct agent in pain management pharmacotherapy. Further, the Inverse-Frequency Analysis methodology provides robust statistical support for the antidepressant action of other currently approved therapeutics including diclofenac and minocycline

Keystroke Biometrics in Response to Fake News Propagation in a Global Pandemic

This work proposes and analyzes the use of keystroke biometrics for content de-anonymization. Fake news have become a powerful tool to manipulate public opinion, especially during major events. In particular, the massive spread of fake news during the COVID-19 pandemic has forced governments and companies to fight against missinformation. In this context, the ability to link multiple accounts or profiles that spread such malicious content on the Internet while hiding in anonymity would enable proactive identification and blacklisting. Behavioral biometrics can be powerful tools in this fight. In this work, we have analyzed how the latest advances in keystroke biometric recognition can help to link behavioral typing patterns in experiments involving 100,000 users and more than 1 million typed sequences. Our proposed system is based on Recurrent Neural Networks adapted to the context of content de-anonymization. Assuming the challenge to link the typed content of a target user in a pool of candidate profiles, our results show that keystroke recognition can be used to reduce the list of candidate profiles by more than 90%. In addition, when keystroke is combined with auxiliary data (such as location), our system achieves a Rank-1 identification performance equal to 52.6% and 10.9% for a background candidate list composed of 1K and 100K profiles, respectively.Comment: arXiv admin note: text overlap with arXiv:2004.0362

Schwarzschild-type black holes in Starobinsky-Bel-Robinson gravity

We study physical properties of a Schwarzschild-type black hole in the framework of the recently proposed Starobinsky-Bel-Robinson (SBR) modified theory of gravity, working perturbatively in the new coupling constant. In particular, we compute the temperature, entropy, pressure and lifetime of a Schwarzschild-type black hole.Comment: 10 pages; v3: one more reference added, final version accepted for publication in Physics Letters

Merging Whole-cell Biosynthesis of Styrene and Transition-metal Catalyzed Derivatization Reactions

The approach of combining enzymatic and transition-metal catalysis has been focused almost exclusively on using purified, isolated enzymes. The use of whole-cell biocatalysis, instead of isolated enzymes, with transition-metal catalysis, however, has been investigated only sparsely to date. Herein we present the development of two transition-metal catalyzed reactions used to derivatize styrene obtained from whole-cell biosynthesis. Using a biocompatible ruthenium cross-metathesis catalyst up to 1.5 mM stilbene could be obtained in the presence of E. coli, which simultaneously produced styrene. Using palladium catalysts and arylboronic acids, titers of up to 1 mM of several stilbene derivatives were obtained. These two transition-metal catalyzed reactions are valuable additions to the toolbox of combined whole-cell biocatalysis and transition-metal catalysis, offering the possibility to supplement biosynthetic pathways with the chemical versatility of abiological transition-metal catalysis

Flat F-theory and friends

We discuss F-theory backgrounds associated to flat torus bundles over Ricci-flat manifolds. In this setting the F-theory background can be understood as a IIB orientifold with a large radius limit described by a supersymmetric compactification of IIB supergravity on a smooth, Ricci flat, but in general non-spin geometry. When compactified on an additional circle these backgrounds are T-dual to IIA compactifications on smooth non-orientable manifolds with a Pin-minus structure.Comment: 26 pages; typos fixed, comments added, discussion of T-duality clarifie

THE MEDIATING EFFECT OF GENERAL SELF-EFFICACY ON THE RELATIONSHIP BETWEEN TRANSFORMATIONAL LEADERSHIP OF SCHOOL HEADS AND ORGANIZATIONAL COMMITMENT OF TEACHERS

The purpose of this study was to determine the mediating effect of general self-efficacy on the relationship between the transformational leadership of school heads and the organizational commitment of teachers. Utilizing quantitative, non-experimental design via correlational technique, data were obtained from 300 elementary public-school teachers who belong to the 3 districts, Magsaysay, Bansalan and Matan-ao under the Division of Davao Del Sur in the province of Davao Del Sur. The researcher utilized a stratified random sampling technique and an online survey mode of data collection. The researcher also utilized the statistical tools mean, Pearson r and Medgraph using Sobel z-test. From the results of the study, it was found out that there is a very high level of mean scores for transformational leadership of school heads, a very high level of the mean score for the organizational commitment of teachers and a high level of general self-efficacy for teachers. Also, results revealed that there are significant relationships between the transformational leadership of school heads and the organizational commitment of teachers, between the transformational leadership of school heads and general self-efficacy of teachers, and between general self-efficacy and organizational commitment of teachers. Further, it was revealed that there was a full mediation effect of general self-efficacy on the relationship between the transformation leadership of school heads and the organizational commitment of teachers.  Article visualizations