51 research outputs found
Exact Virasoro Blocks from Wilson Lines and Background-Independent Operators
Aspects of black hole thermodynamics and information loss can be derived as a
consequence of Virasoro symmetry. To bolster the connection between Virasoro
conformal blocks and AdS quantum gravity, we study sl Chern-Simons
Wilson line networks and revisit the idea that they compute a variety of
CFT observables, including Virasoro OPE blocks, exactly. We verify this in
the semiclassical large central charge limit and to low orders in a
perturbative expansion.
Wilson lines connecting the boundary to points in the bulk play a natural
role in bulk reconstruction. Because quantum gravity in AdS is rigidly
fixed by Virasoro symmetry, we argue that sl Wilson lines provide building
blocks for background independent bulk reconstruction. In particular, we show
explicitly that they automatically compute the uniformizing coordinates
appropriate to any background state.Comment: V3- Added some references V2- Significantly Expanded Appendix on
Regulation; 32+21 page
Degenerate Operators and the Expansion: Lorentzian Resummations, High Order Computations, and Super-Virasoro Blocks
One can obtain exact information about Virasoro conformal blocks by
analytically continuing the correlators of degenerate operators. We argued in
recent work that this technique can be used to explicitly resolve information
loss problems in AdS/CFT. In this paper we use the technique to perform
calculations in the small expansion: (1) we prove the
all-orders resummation of logarithmic factors in
the Lorentzian regime, demonstrating that corrections directly shift
Lyapunov exponents associated with chaos, as claimed in prior work, (2) we
perform another all-orders resummation in the limit of large with fixed
, interpolating between the early onset of chaos and late time behavior,
(3) we explicitly compute the Virasoro vacuum block to order and
, corresponding to and loop calculations in AdS, and (4) we
derive the heavy-light vacuum blocks in theories with
superconformal symmetry.Comment: 34+20 pages, 2 figure
Numerical Investigation on Convergence Rate of Singular Boundary Method
The singular boundary method (SBM) is a recent boundary-type collocation scheme with the merits of being free of mesh and integration, mathematically simple, and easy-to-program. Its essential technique is to introduce the concept of the source intensity factors to eliminate the singularities of fundamental solutions upon the coincidence of source and collocation points in a strong-form formulation. In recent years, several numerical and semianalytical techniques have been proposed to determine source intensity factors. With the help of these latest techniques, this short communication makes an extensive investigation on numerical efficiency and convergence rates of the SBM to an extensive variety of benchmark problems in comparison with the BEM. We find that in most cases the SBM and BEM have similar convergence rates, while the SBM has slightly better accuracy than the direct BEM. And the condition number of SBM is lower than BEM. Without mesh and numerical integration, the SBM is computationally more efficient than the BEM
Emerging role of ferroptosis-related circular RNA in tumor metastasis
Tumor metastasis is an important factor that contributes to the poor prognosis of patients with tumors. Therefore, to solve this problem, research on the mechanism of metastasis is essential. Ferroptosis, a new mode of cell death, is characterized by membrane damage due to lipid peroxidation caused by iron overload. Many studies have shown that excessive ferroptosis can affect tumor metastasis and thus inhibit tumor progression. Recently, circular RNA (circRNA), a type of non-coding RNA, has been shown to be associated with the progression of ferroptosis, thus influencing tumor development. However, the specific mechanisms by which circRNAs affect the progression of ferroptosis and their roles in tumor metastasis are not known. In this review, we systematically discuss the role of circRNAs in regulating tumor ferroptosis and their mechanism of action through sponging miRNAS in various tumors, thereby impacting metastasis. This review helps elucidate the relationship and role of ferroptosis-related circRNAs in tumor metastasis and may provide future researchers with new ideas and directions for targeted therapies
A regularized approach evaluating origin intensity factor of singular boundary method for Helmholtz equation with high wavenumbers
Evaluation of the origin intensity factor of the singular boundary method for Helmholtz equation with high wavenumbers has been a difficult task for a long time. In this study, a regularized approach is provided to bypass this limitation. The core idea of the subtraction and adding-back technique is to substitute an artificially constructed general solution of the Helmholtz equation into the boundary integral equation or the hyper boundary integral equation to evaluate the non-singular expressions of the fundamental solutions at origin. The core difficulty is to derive the appropriate artificially constructed general solution. The regularized approach avoids the unstable inverse interpolation and has strict mathematical derivation process. Therefore, it is easy-to-program and free of mesh dependency. Numerical experiments show that the proposed technique can be used successfully to avoid singularity and hyper singularity difficulties encountered in the boundary element method and the singular boundary method.The work was supported by the Fundamental Research Funds for the Central Universities (Grant Nos. 2018B40714, 2016B06214, 2017B709X14), the National Science Funds of China 11572111, 11772119), the Foundation for Open Project of State Key Laboratory of Structural Analysis for Industrial Equipment (Grant No. GZ1707), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. KYCX17_0488) and the Postgraduate Scholarship Program from the China Scholarship Council (Grant No. 201706710107)
Proteomics-based analysis of differentially expressed proteins in the CXCR1-knockdown gastric carcinoma MKN45 cell line and its parental cell
C-X-C chemokine receptor types 1 (CXCR1), a cell-surface G-protein-coupled receptor has been found to be associated with tumorigenesis, development, and progression of some tumors. Previously, we have found that CXCR1 overexpression is associated with late-stage gastric adenocarcinoma. We also have demonstrated that knockdown of CXCR1 could inhibit cell proliferation in vitro and in vivo. In this study, we compared the changes of protein expression profile between gastric carcinoma MKN45 cell line and CXCR1-knockdown MKN45 cell line by 2D electrophoresis. Among the 101 quantified proteins, 29 spots were significantly different, among which 13 were downregulated and 16 were up-regulated after CXCR1 knockdown. These proteins were further identified by mass spectrometry analysis. Among them, several up-regulated proteins such as hCG2020155, Keratin8, heterogeneous nuclear ribonucleoprotein C (C1/C2), and several downregulated proteins such as Sorcin, heat shock protein 27, serpin B6 isoform b, and heterogeneous nuclear ribonucleoprotein K were confirmed. These proteins are related to cell cycle, the transcription regulation, cell adherence, cellular metabolism, drug resistance, and so on. These results provide an additional support to the hypothesis that CXCR1 might play an important role in proliferation, invasion, metastasis, and prognosis, and drug resistance of gastric carcinoma
The IFN-γ-related long non-coding RNA signature predicts prognosis and indicates immune microenvironment infiltration in uterine corpus endometrial carcinoma
BackgroundOne of the most common diseases that have a negative impact on women’s health is endometrial carcinoma (EC). Advanced endometrial cancer has a dismal prognosis and lacks solid prognostic indicators. IFN-γ is a key cytokine in the inflammatory response, and it has also been suggested that it has a role in the tumor microenvironment. The significance of IFN-γ-related genes and long non-coding RNAs in endometrial cancer, however, is unknown.MethodsThe Cancer Genome Atlas (TCGA) database was used to download RNA-seq data from endometrial cancer tissues and normal controls. Genes associated with IFN-γ were retrieved from the gene set enrichment analysis (GSEA) website. Co-expression analysis was performed to find lncRNAs linked to IFN-γ gene. The researchers employed weighted co-expression network analysis (WGCNA) to find lncRNAs that were strongly linked to survival. The prognostic signature was created using univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression. The training cohort, validation cohort, and entire cohort of endometrial cancer patients were then split into high-risk and low-risk categories. To investigate variations across different risk groups, we used survival analysis, enrichment analysis, and immune microenvironment analysis. The platform for analysis is R software (version X64 3.6.1).ResultsBased on the transcript expression of IFN-γ-related lncRNAs, two distinct subgroups of EC from TCGA cohort were formed, each with different outcomes. Ten IFN-γ-related lncRNAs were used to build a predictive signature using Cox regression analysis and the LASSO regression, including CFAP58, LINC02014, UNQ6494, AC006369.1, NRAV, BMPR1B-DT, AC068134.2, AP002840.2, GS1-594A7.3, and OLMALINC. The high-risk group had a considerably worse outcome (p < 0.05). In the immunological microenvironment, there were also substantial disparities across different risk categories.ConclusionOur findings give a reference for endometrial cancer prognostic type and immunological status assessment, as well as prospective molecular markers for the disease
A comprehensive genome variation map of melon identifies multiple domestication events and loci influencing agronomic traits
Melon is an economically important fruit crop that has been cultivated for thousands of years; however, the genetic basis and history of its domestication still remain largely unknown. Here we report a comprehensive map of the genomic variation in melon derived from the resequencing of 1,175 accessions, which represent the global diversity of the species. Our results suggest that three independent domestication events occurred in melon, two in India and one in Africa. We detected two independent sets of domestication sweeps, resulting in diverse characteristics of the two subspecies melo and agrestis during melon breeding. Genome-wide association studies for 16 agronomic traits identified 208 loci significantly associated with fruit mass, quality and morphological characters. This study sheds light on the domestication history of melon and provides a valuable resource for genomics-assisted breeding of this important crop.This work was supported by funding from the Agricultural Science and Technology Innovation Program (to Yongyang Xu, S.H., Z.Z. and H.W.), the China Agriculture Research System (CARS-25 to Yongyang Xu and H.W.), the Leading Talents of Guangdong Province Program (00201515 to S.H.), the Shenzhen Municipal (The Peacock Plan KQTD2016113010482651 to S.H.), the Dapeng district government, National Natural Science Foundation of China (31772304 to Z.Z.), the Science and Technology Program of Guangdong (2018B020202007 to S.H.), the National Natural Science Foundation of China (31530066 to S.H.), the National Key R&D Program of China (2016YFD0101007 to S.H.), USDA National Institute of Food and Agriculture Specialty Crop Research Initiative (2015-51181-24285 to Z.F.), the European Research Council (ERC-SEXYPARTH to A.B.), the Spanish Ministry of Economy and Competitiveness (AGL2015–64625-C2-1-R to J.G.-M.), Severo Ochoa Programme for Centres of Excellence in R&D 2016–2010 (SEV-2015–0533 to J.G.-M.), the CERCA Programme/Generalitat de Catalunya to J.G.-M. and the German Science Foundation (SPP1991 Taxon-OMICS to H.S.)
A comprehensive genome variation map of melon identifies multiple domestication events and loci influencing agronomic traits
Melon is an economically important fruit crop that has been cultivated for thousands of years; however, the genetic basis and
history of its domestication still remain largely unknown. Here we report a comprehensive map of the genomic variation in
melon derived from the resequencing of 1,175 accessions, which represent the global diversity of the species. Our results suggest that three independent domestication events occurred in melon, two in India and one in Africa. We detected two independent sets of domestication sweeps, resulting in diverse characteristics of the two subspecies melo and agrestis during melon
breeding. Genome-wide association studies for 16 agronomic traits identified 208 loci significantly associated with fruit mass,
quality and morphological characters. This study sheds light on the domestication history of melon and provides a valuable
resource for genomics-assisted breeding of this important crop.info:eu-repo/semantics/acceptedVersio
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