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"Ying, Lin"
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Modular bootstrap revisited
A
bstract
We constrain the spectrum of two-dimensional unitary, compact conformal field theories with central charge
c >
1 using modular bootstrap. Upper bounds on the gap in the dimension of primary operators of any spin, as well as in the dimension of scalar primaries, are computed numerically as functions of the central charge using semi-definite programming. Our bounds refine those of Hellerman and Friedan-Keller, and are in some cases saturated by known CFTs. In particular, we show that unitary CFTs with
c <
8 must admit relevant deformations, and that a nontrivial bound on the gap of scalar primaries exists for
c <
25. We also study bounds on the dimension gap in the presence of twist gaps, bounds on the degeneracy of operators, and demonstrate how “extremal spectra” which maximize the degeneracy at the gap can be determined numerically.
Journal Article
Risk Factors for Invasive Cryptococcus neoformans Diseases: A Case-Control Study
Cryptococcus neoformans is a ubiquitous environmental fungus that can cause life-threatening meningitis and fungemia, often in the presence of acquired immunodeficiency syndrome (AIDS), liver cirrhosis, diabetes mellitus, or other medical conditions. To distinguish risk factors from comorbidities, we performed a hospital-based, density-sampled, matched case-control study.
All new-onset cryptococcal meningitis cases and cryptococcemia cases at a university hospital in Taiwan from 2002-2010 were retrospectively identified from the computerized inpatient registry and were included in this study. Controls were selected from those hospitalized patients not experiencing cryptococcal meningitis or cryptococcemia. Controls and cases were matched by admission date, age, and gender. Conditional logistic regression was used to analyze the risk factors.
A total of 101 patients with cryptococcal meningitis (266 controls) and 47 patients with cryptococcemia (188 controls), of whom 32 patients had both cryptococcal meningitis and cryptococcemia, were included in this study. Multivariate regression analysis showed that AIDS (adjusted odds ratio [aOR] = 181.4; p < 0.001), decompensated liver cirrhosis (aOR = 8.5; p = 0.008), and cell-mediated immunity (CMI)-suppressive regimens without calcineurin inhibitors (CAs) (aOR = 15.9; p < 0.001) were independent risk factors for cryptococcal meningitis. Moreover, AIDS (aOR = 216.3, p < 0.001), decompensated liver cirrhosis (aOR = 23.8; p < 0.001), CMI-suppressive regimens without CAs (aOR = 7.3; p = 0.034), and autoimmune diseases (aOR = 9.3; p = 0.038) were independent risk factors for developing cryptococcemia. On the other hand, diabetes mellitus and other medical conditions were not found to be risk factors for cryptococcal meningitis or cryptococcemia.
The findings confirm AIDS, decompensated liver cirrhosis, CMI-suppressive regimens without CAs, and autoimmune diseases are risk factors for invasive C. neoformans diseases.
Journal Article
Design of urban road fault detection system based on artificial neural network and deep learning
In urban traffic management, the timely detection of road faults plays a crucial role in improving traffic efficiency and safety. However, conventional methods often fail to fully leverage the information from road topology and traffic data.
To address this issue, we propose an innovative detection system that combines Artificial Neural Networks (ANNs), specifically Graph Convolutional Networks (GCN), Bidirectional Gated Recurrent Units (BiGRU), and self-attention mechanisms. Our approach begins by representing the road topology as a graph and utilizing GCN to model it. This allows us to learn the relationships between roads and capture their structural dependencies. By doing so, we can effectively incorporate the spatial information provided by the road network. Next, we employ BiGRU to model the historical traffic data, enabling us to capture the temporal dynamics and patterns in the traffic flow. The BiGRU architecture allows for bidirectional processing, which aids in understanding the traffic conditions based on both past and future information. This temporal modeling enhances our system's ability to handle time-varying traffic patterns. To further enhance the feature representations, we leverage self-attention mechanisms. By combining the hidden states of the BiGRU with self-attention, we can assign importance weights to different temporal features, focusing on the most relevant information. This attention mechanism helps to extract salient features from the traffic data. Subsequently, we merge the features learned by GCN from the road topology and BiGRU from the traffic data. This fusion of spatial and temporal information provides a comprehensive representation of the road status.
By employing a Multilayer Perceptron (MLP) as a classifier, we can effectively determine whether a road is experiencing a fault. The MLP model is trained using labeled road fault data through supervised learning, optimizing its performance for fault detection. Experimental evaluations of our system demonstrate excellent performance in road fault detection. Compared to traditional methods, our system achieves more accurate fault detection, thereby improving the efficiency of urban traffic management. This is of significant importance for city administrators, as they can promptly identify road faults and take appropriate measures for repair and traffic diversion.
Journal Article
Construction of two-dimensional topological field theories with non-invertible symmetries
A
bstract
We construct the defining data of two-dimensional topological field theories (TFTs) enriched by non-invertible symmetries/topological defect lines. Simple formulae for the three-point functions and the lasso two-point functions are derived, and crossing symmetry is proven. The key ingredients are open-to-closed maps and a boundary crossing relation, by which we show that a diagonal basis exists in the defect Hilbert spaces. We then introduce regular TFTs, provide their explicit constructions for the Fibonacci, Ising and Haagerup ℋ
3
fusion categories, and match our formulae with previous bootstrap results. We end by explaining how non-regular TFTs are obtained from regular TFTs via generalized gauging.
Journal Article
Asymptotic density of states in 2d CFTs with non-invertible symmetries
A
bstract
It is known that the asymptotic density of states of a 2d CFT in an irreducible representation
ρ
of a finite symmetry group
G
is proportional to (dim
ρ
)
2
. We show how this statement can be generalized when the symmetry can be non-invertible and is described by a fusion category
C
. Along the way, we explain what plays the role of a representation of a group in the case of a fusion category symmetry; the answer to this question is already available in the broader mathematical physics literature but not yet widely known in hep-th. This understanding immediately implies a selection rule on the correlation functions, and also allows us to derive the asymptotic density.
Journal Article
Words to describe a black hole
A
bstract
We revamp the constructive enumeration of 1/16-BPS states in the maximally supersymmetric Yang-Mills in four dimensions, and search for ones that are not of multi-graviton form. A handful of such states are found for gauge group SU(2) at relatively high energies, resolving a decade-old enigma. Along the way, we clarify various subtleties in the literature, and prove a non-renormalization theorem about the exactness of the cohomological enumeration in perturbation theory. We point out a giant-graviton-like feature in our results, and envision that a deep analysis of our data will elucidate the fundamental properties of black hole microstates.
Journal Article
Lorentzian dynamics and factorization beyond rationality
A
bstract
We investigate the emergence of topological defect lines in the conformal Regge limit of two-dimensional conformal field theory. We explain how a local operator can be factorized into a holomorphic and an anti-holomorphic defect operator connected through a topological defect line, and discuss implications on analyticity and Lorentzian dynamics including aspects of chaos. We derive a formula relating the infinite boost limit, which holographically encodes the “opacity” of bulk scattering, to the action of topological defect lines on local operators. Leveraging the unitary bound on the opacity and the positivity of fusion coefficients, we show that the spectral radii of a large class of topological defect lines are given by their loop expectation values. Factorization also gives a formula relating the local and defect operator algebras and fusion categorical data. We then review factorization in rational conformal field theory from a defect perspective, and examine irrational theories. On the orbifold branch of the
c
= 1 free boson theory, we find a unified description for the topological defect lines through which the twist fields are factorized; at irrational points, the twist fields factorize through “non-compact” topological defect lines which exhibit continuous defect operator spectra. Along the way, we initiate the development of a formalism to characterize non-compact topological defect lines.
Journal Article
A Review of SARS-CoV-2 and the Ongoing Clinical Trials
The sudden outbreak of 2019 novel coronavirus (2019-nCoV, later named SARS-CoV-2) in Wuhan, China, which rapidly grew into a global pandemic, marked the third introduction of a virulent coronavirus into the human society, affecting not only the healthcare system, but also the global economy. Although our understanding of coronaviruses has undergone a huge leap after two precedents, the effective approaches to treatment and epidemiological control are still lacking. In this article, we present a succinct overview of the epidemiology, clinical features, and molecular characteristics of SARS-CoV-2. We summarize the current epidemiological and clinical data from the initial Wuhan studies, and emphasize several features of SARS-CoV-2, which differentiate it from SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), such as high variability of disease presentation. We systematize the current clinical trials that have been rapidly initiated after the outbreak of COVID-19 pandemic. Whereas the trials on SARS-CoV-2 genome-based specific vaccines and therapeutic antibodies are currently being tested, this solution is more long-term, as they require thorough testing of their safety. On the other hand, the repurposing of the existing therapeutic agents previously designed for other virus infections and pathologies happens to be the only practical approach as a rapid response measure to the emergent pandemic, as most of these agents have already been tested for their safety. These agents can be divided into two broad categories, those that can directly target the virus replication cycle, and those based on immunotherapy approaches either aimed to boost innate antiviral immune responses or alleviate damage induced by dysregulated inflammatory responses. The initial clinical studies revealed the promising therapeutic potential of several of such drugs, including favipiravir, a broad-spectrum antiviral drug that interferes with the viral replication, and hydroxychloroquine, the repurposed antimalarial drug that interferes with the virus endosomal entry pathway. We speculate that the current pandemic emergency will be a trigger for more systematic drug repurposing design approaches based on big data analysis.
Journal Article
Examining the effects of second-and third-trimester gestational weight gain rates on the perinatal outcomes among Chinese twin pregnancies: a retrospective cohort study
Background
This paper investigated how second- and third-trimester gestational weight gain relates to perinatal outcomes among normal weight women with twin pregnancies in Fujian, China.
Methods
A retrospective study examining the medical records of 931 normal weight twin-pregnant women was conducted in Fujian Maternity and Child Health Hospital from 2014 to 2018.The 2
nd
and 3
rd
trimester weekly weight gain rates were calculated, and women were categorized as gaining below, within, or above the 2009 Institute of Medicine (IOM) recommended rates. The association between the trimester-specific weight gain rate and perinatal outcome was determined by traditional regression analysis among groups.
Results
A total of 25.9%, 19.8% and 54.3% of women had rates of weight gain across the 2
nd
and 3
rd
trimesters less than, greater than or within the recommended rates respectively. Multivariate logistic regression analysis showed that weight gain greater than the recommended rate in the 2
nd
trimester was associated with a decreased risk of preeclampsia (aOR:0.489,95%CI:0.289 ~ 0.974). Weight gain less than the recommended rate of weight gain in the 3
rd
trimester was associated with increased risks of premature delivery(aOR:2.079, 95%CI:1.467 ~ 2.968), gestational diabetes mellitus (aOR: 2.048, 95%CI:1.411 ~ 2.971), intrahepatic cholestasis syndrome (aOR:3.015,95%CI: 1.058 ~ 8.587), pre-labour rupture of membrane (aOR: 1.708,95%CI: 1.169 ~ 2.493), average twin birth weight < 2500 g(aOR:1.532,95%CI: 1.125 ~ 2.084) and neonatal respiratory distress syndrome (aOR:4.934,95%CI:1.626 ~ 15.083) and was associated with decreased risks of caesarean section (aOR:0.589,95%CI:0.386 ~ 0.898) and preeclampsia (aOR:0.471, 95%CI:0.274 ~ 0.808). In addition, weight gain greater than the recommended rate of weight gain in the 3
rd
trimester was associated with increased risks of premature delivery (aOR:1.589,95%CI:1.428 ~ 2.951) and gestational hypertension (aOR:2.137,95% CI:1.034 ~ 4.415) as well as preeclampsia (aOR:2.246, 95%CI:1.462 ~ 3.452). The stratified analysis of weight gain in the 3
rd
trimester showed that there was no significant difference in the incidence of adverse pregnancy outcomes compared to the 2
nd
trimester weight gain groups.
Conclusions
While this study showed that a gestational weight gain rate above or below the recommendation in the 3
rd
trimester was associated with some adverse maternal and neonatal outcomes, further prospective and multicentre studies are required to explore alternate ranges of gestational weight gain rates in twin pregnancies.
Journal Article