9,735 research outputs found
Strong deflection gravitational lensing by a modified Hayward black hole
A modified Hayward black hole is a nonsingular black hole. It is proposed to
form when the pressure generated by quantum gravity can stop matter's collapse
as the matter reaches Planck density. Strong deflection gravitational lensing
happening nearby its event horizon might provide some clues of these quantum
effects in its central core. We investigate observables of the strong
deflection lensing, including angular separations, brightness differences and
time delays between its relativistic images, and estimate their values for the
supermassive black hole in the Galactic center. We find that it is possible to
distinguish the modified Hayward black hole from a Schwarzschild one, but it
demands very high resolution beyond current stage.Comment: 10 pages, 1 figur
Attention-Based End-to-End Speech Recognition on Voice Search
Recently, there has been a growing interest in end-to-end speech recognition
that directly transcribes speech to text without any predefined alignments. In
this paper, we explore the use of attention-based encoder-decoder model for
Mandarin speech recognition on a voice search task. Previous attempts have
shown that applying attention-based encoder-decoder to Mandarin speech
recognition was quite difficult due to the logographic orthography of Mandarin,
the large vocabulary and the conditional dependency of the attention model. In
this paper, we use character embedding to deal with the large vocabulary.
Several tricks are used for effective model training, including L2
regularization, Gaussian weight noise and frame skipping. We compare two
attention mechanisms and use attention smoothing to cover long context in the
attention model. Taken together, these tricks allow us to finally achieve a
character error rate (CER) of 3.58% and a sentence error rate (SER) of 7.43% on
the MiTV voice search dataset. While together with a trigram language model,
CER and SER reach 2.81% and 5.77%, respectively
2-MethylÂbenzaldehyde 2-methylÂbenzylÂidenehydrazone
The molÂecule of the title compound, C16H16N2, is centrosymmetric and the dihedral angle between the benzene ring and the dimethylÂhydrazine mean plane is 16.11 (15)°
Genistein promotes cell death of ethanol-stressed HeLa cells through the continuation of apoptosis or secondary necrosis.
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Apoptosis is a major target and treatment effect of multiple chemotherapeutical agents in cancer. A soybean isoflavone, genistein, is a well-studied chemopreventive agent and has been reported to potentiate the anticancer effect of some chemotherapeutics. However, its mechanistic basis of chemo-enhancement effect remains to be fully elucidated. METHODS: Apoptotic features of low concentration stressed cancer cells were studied by microscopic method, western blot, immunostaining and annexin V/PI assay. Genistein's effects on unstressed cells and recovering cells were investigated using MTT cell viability assay and LDH cytotoxicity assay. Quantitative real-time PCR was employed to analyze the possible gene targets involved in the recovery and genistein's effect. RESULTS: Low-concentration ethanol stressed cancer cells showed apoptotic features and could recover after stress removal. In stressed cells, genistein at sub-toxic dosage promoted the cell death. Quantitative real-time PCR revealed the up-regulation of anti-apoptotic genes MDM2 and XIAP during the recovery process in HeLa cells, and genistein treatment suppressed their expression. The application of genistein, MDM2 inhibitor and XIAP inhibitor to the recovering HeLa cells caused persistent caspase activity and enhanced cell death. Flow cytometry study indicated that genistein treatment could lead to persistent phosphatidylserine (PS) externalization and necrotic events in the recovering HeLa cells. Caspase activity inhibition shifted the major effect of genistein to necrosis. CONCLUSIONS: These results suggested two possible mechanisms through which genistein promoted cell death in stressed cancer cells. Genistein could maintain the existing apoptotic signal to enhance apoptotic cell death. It could also disrupt the recovering process in caspase-independent manner, which lead to necrotic events. These effects may be related to the enhanced antitumor effect of chemotherapeutic drugs when they were combined with genistein
Mirror symmetry for circle compactified 4d SCFTs
We propose a mirror symmetry for 4d superconformal field
theories (SCFTs) compactified on a circle with finite size. The mirror symmetry
involves vertex operator algebra (VOA) describing the Schur sector (containing
Higgs branch) of 4d theory, and the Coulomb branch of the effective 3d theory.
The basic feature of the mirror symmetry is that many representational
properties of VOA are matched with geometric properties of the Coulomb branch
moduli space. Our proposal is verified for a large class of Argyres-Douglas
(AD) theories engineered from M5 branes, whose VOAs are W-algebras, and Coulomb
branches are the Hitchin moduli spaces. VOA data such as simple modules, Zhu's
algebra, and modular properties are matched with geometric properties like
-fixed varieties in Hitchin fibers, cohomologies, and some DAHA
representations. We also mention relationships to 3d symplectic duality.Comment: 53 pages, 6 figure
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