1,135 research outputs found
From Horndeski action to the Callan-Giddings-Harvey-Strominger model and beyond
The knowledge of what entered black hole (BH) is completely lost as it
evaporates. This contradicts the unitarity principle of quantum mechanics and
is referred to as the information loss paradox. Understanding the end stages of
BH evaporation is key to resolving this paradox. As a first step, we need to
have exact models that can mimic 4-D BHs in General relativity in classical
limit and have a systematic way to include high-energy corrections. While there
are various models in the literature, there is no systematic procedure by which
one can study high-energy corrections. In this work, for the first time, we
obtain Callan, Giddings, Harvey, and Strominger (CGHS) -- a (1+1)-D -- model
from 4-D Horndeski action -- the most general scalar-tensor theory that does
not lead to Ostrogradsky ghosts. We then show that 4-D Horndeski action can
systematically provide a route to include higher-derivative terms relevant at
the end stages of black hole evaporation. We derive the leading order Hawking
flux while discussing some intriguing characteristics of the corrected CGHS
models. We compare our results with other works and discuss the implications
for primordial BHs.Comment: V2: Version accepted in PRD Letters. The title is modified. 34 Pages,
4 figures (including supplementary material
Biolistic transformation of Saccharomyces cerevisiae with β-glucosidase gene from Cellulomonas biazotea
A β-glucosidase genomic DNA from Cellulomonas biazotea NIAB 442 was isolated and coated onto tungsten microprojectiles for direct transformation of the gene into Saccharomyces cerevisiae. Transformation of β-glucosidase into S. cerevisae conferred the ability to hydrolyse esculin and cellobiose, indicated that the gene is expressed in the bombarded yeast.
Key Words: Biolistic transformation, β-glucosidase, Cellulomonas biazotea, Saccharomyces cerevisiae.
African Journal of Biotechnology Vol.3(1) 2004: 112-11
(R)-Doxylaminium (R,R)-tartrate
In the title compound (systematic name: (R)-dimethyl{2-[1-phenyl-1-(pyridin-2-yl)ethoxy]ethyl}azanium (R,R)-3-carboxy-2,3-dihydroxypropanoate), C17H23N2O+·C4H5O6
−, the doxylaminium cation is protonated at the N atom. The tartrate monoanions are linked by short, almost linear O—H⋯O hydrogen bonds into chains extended along [100]. These chains are interlinked by anion–pyridine O—H⋯N hydrogen bonds into a two-dimensional grid structure. WeakC—H⋯O interactions also play a role in the crystal packing. An intramolecular hydroxy–carboxylate O—H⋯O hydrogen bond influences the conformation of the anion: the hydrogen-bonded fragment is almost planar, the maximum deviation from the mean plane being 0.059 (14) Å. In the cation, the aromatic rings are almost perpendicular [dihedral angle = 84.94 (8)°] and the conformation of the O—C—C—N chain is gauche(−), the dihedral angle is −76.6 (2)°. The absolute configuration was assigned on the basis of known chirality of the parent compound
Authorship Identification of Source Code Segments Written by Multiple Authors Using Stacking Ensemble Method
Source code segment authorship identification is the task of identifying the
author of a source code segment through supervised learning. It has vast
importance in plagiarism detection, digital forensics, and several other law
enforcement issues. However, when a source code segment is written by multiple
authors, typical author identification methods no longer work. Here, an author
identification technique, capable of predicting the authorship of source code
segments, even in the case of multiple authors, has been proposed which uses a
stacking ensemble classifier. This proposed technique is built upon several
deep neural networks, random forests and support vector machine classifiers. It
has been shown that for identifying the author group, a single classification
technique is no longer sufficient and using a deep neural network-based
stacking ensemble method can enhance the accuracy significantly. The
performance of the proposed technique has been compared with some existing
methods which only deal with the source code segments written precisely by a
single author. Despite the harder task of authorship identification for source
code segments written by multiple authors, our proposed technique has achieved
promising results evidenced by the identification accuracy, compared to the
related works which only deal with code segments written by a single author.Comment: 2019 22nd International Conference on Computer and Information
Technology (ICCIT
Configuration Detection of Grounding Grid: Static Electric Field Based Nondestructive Technique
Grounding grid configuration which, is key to its fault diagnosis, changes continuously with the extension in a substation. Furthermore, older substations grounding grid configurations are unknown. Existing literature regarding configuration detection mainly accounts for the magnetic field that required a gradient to locate the grounding conductor. The gradient of raw measurement in the substation vicinity enhances electromagnetic noise and distorts the results. Therefore, in this paper, we have developed a new algorithm, Configuration Detection of Grounding Grid (CDGG) based on the static electric field and the concept of ordered pairs to draw the configuration of the unknown grounding grid. Unlike, the practiced magnetic field, the electric field does not require a gradient. The maximum electric field value indicates the location of a grounding conductor. The connection between nodes is verified by measuring the electric field on the circle. Furthermore, the proposed algorithm also locates any diagonal conductor in the configuration. Mathematical reasoning and simulation results illustrate that our proposed algorithm is feasible to draw the configuration of the unknown grounding grid
Wdr1 and cofilin are necessary mediators of immune-cell-specific apoptosis triggered by Tecfidera.
Despite the emerging importance of reactive electrophilic drugs, deconvolution of their principal targets remains difficult. The lack of genetic tractability/interventions and reliance on secondary validation using other non-specific compounds frequently complicate the earmarking of individual binders as functionally- or phenotypically-sufficient pathway regulators. Using a redox-targeting approach to interrogate how on-target binding of pleiotropic electrophiles translates to a phenotypic output in vivo, we here systematically track the molecular components attributable to innate immune cell toxicity of the electrophilic-drug dimethyl fumarate (Tecfidera®). In a process largely independent of canonical Keap1/Nrf2-signaling, Keap1-specific modification triggers mitochondrial-targeted neutrophil/macrophage apoptosis. On-target Keap1-ligand-engagement is accompanied by dissociation of Wdr1 from Keap1 and subsequent coordination with cofilin, intercepting Bax. This phagocytic-specific cell-killing program is recapitulated by whole-animal administration of dimethyl fumarate, where individual depletions of the players identified above robustly suppress apoptosis
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