1,539 research outputs found
Dynamical spontaneous scalarization in Einstein-Maxwell-scalar models in anti-de Sitter spacetime
The phenomenon of spontaneous scalarization of charged black holes has
attracted a lot of attention. In this work, we study the dynamical process of
the spontaneous scalarization of charged black hole in asymptotically anti-de
Sitter spacetimes in Einstein-Maxwell-scalar models. Including various
non-minimal couplings between the scalar field and Maxwell field, we observe
that an initial scalar-free configuration suffers tachyonic instability and
both the scalar field and the black hole irreducible mass grow exponentially at
early times and saturate exponentially at late times. For fractional couplings,
we find that though there is negative energy distribution near the black hole
horizon, the black hole horizon area never decreases. But when the parameters
are large, the evolution endpoints of linearly unstable bald black holes will
be spacetimes with naked singularity and the cosmic censorship is violated. The
effects of the black hole charge, cosmological constant and coupling strength
on the dynamical scalarization process are studied in detail. We find that
large enough cosmological constant can prevent the spontaneous scalarization.Comment: 20pages,8figure
Quantitative analysis reveals increased histone modifications and a broad nucleosome-free region bound by histone acetylases in highly expressed genes in human CD4+ T cells
AbstractGenome-wide mapping of nucleosomes and histone modifications revealed meaningful patterns. Despite advances in resolving the associations between chromatin and transcription, quantitative chromatin dynamics have not been well defined. We quantitatively determined differences in histone modifications, nucleosome positions, DNA methylation, and transcription factor binding in highly expressed and repressed genes in human CD4+ T cells. We showed that the first (−1) nucleosome upstream of the transcription start site (TSS) is shifted to the 5′ direction, thus forming a broad nucleosome-free region (NFR) near the TSS in highly expressed genes in CD4+ T cells. Moreover, the transcription factor YY1 and histone acetyltransferases bind the NFR with high affinity. Most of histone acetylations drastically increase in transcription activation (>5 folds). We also suggested that single nucleotide polymorphisms (SNPs) occur at a much lower frequency in highly expressed genes than in repressed genes. Our analysis quantitatively revealed details of chromatin dynamics
Dynamical transitions in scalarization and descalarization through black hole accretion
We present the first fully nonlinear study on the accretion of scalar fields
onto a seed black hole in anti-de Sitter spacetime in Einstein-Maxwell-scalar
theory. Intrinsic critical phenomena in the dynamical transition between the
bald and scalarized black holes are disclosed. In scalarizations, the
transition is discontinuous and a metastable black hole acts as an attractor at
the threshold. We construct a new physical mechanism to dynamically descalarize
an isolated scalarized black hole. The first results on critical phenomena in
descalarizations are revealed. The dynamical descalarizations can be either
discontinuous or continuous at the threshold, distinguished by whether or not
an attractor appears
GM-TCNet: Gated Multi-scale Temporal Convolutional Network using Emotion Causality for Speech Emotion Recognition
In human-computer interaction, Speech Emotion Recognition (SER) plays an
essential role in understanding the user's intent and improving the interactive
experience. While similar sentimental speeches own diverse speaker
characteristics but share common antecedents and consequences, an essential
challenge for SER is how to produce robust and discriminative representations
through causality between speech emotions. In this paper, we propose a Gated
Multi-scale Temporal Convolutional Network (GM-TCNet) to construct a novel
emotional causality representation learning component with a multi-scale
receptive field. GM-TCNet deploys a novel emotional causality representation
learning component to capture the dynamics of emotion across the time domain,
constructed with dilated causal convolution layer and gating mechanism.
Besides, it utilizes skip connection fusing high-level features from different
gated convolution blocks to capture abundant and subtle emotion changes in
human speech. GM-TCNet first uses a single type of feature, mel-frequency
cepstral coefficients, as inputs and then passes them through the gated
temporal convolutional module to generate the high-level features. Finally, the
features are fed to the emotion classifier to accomplish the SER task. The
experimental results show that our model maintains the highest performance in
most cases compared to state-of-the-art techniques.Comment: The source code is available at:
https://github.com/Jiaxin-Ye/GM-TCNe
Transiently Impaired Endothelial Function During Thyroid Hormone Withdrawal in Differentiated Thyroid Cancer Patients
PURPOSE: Endothelial dysfunction, which was associated with chronic hypothyroidism, was an early event in atherosclerosis. Whether short-term hypothyroidism following thyroxine withdrawal during radioiodine (RAI) therapy was associated with endothelial dysfunction in patients with differentiated thyroid cancer (DTC) was unclear. Aim of the study was to assess whether short-term hypothyroidism could impair endothelial function and the accompanied metabolic changes in the whole process of RAI therapy.
METHODS: We recruited fifty-one patients who underwent total thyroidectomy surgery and would accept RAI therapy for DTC. We analyzed thyroid function, endothelial function and serum lipids levels of the patients at three time points: the day before thyroxine withdrawal(P
RESULTS: We analyzed the changes of FMD, thyroid function and lipids at three time points. FMD(P
CONCLUSION: Endothelial function was transiently impaired in DTC patients at short-term hypothyroidism state during the RAI therapy, and immediately returned to the initial state after restoring TSH suppression therapy
- …