2,050 research outputs found
Incomplete Augmented Lagrangian Preconditioner for Steady Incompressible Navier-Stokes Equations
An incomplete augmented Lagrangian preconditioner, for the steady incompressible Navier-Stokes equations discretized by stable finite elements, is proposed. The eigenvalues of the preconditioned matrix are analyzed. Numerical experiments show that the incomplete augmented Lagrangian-based preconditioner proposed is very robust and performs quite well by the Picard linearization or the Newton linearization over a wide range of values of the viscosity on both uniform and stretched grids
Sharing, Teaching and Aligning: Knowledgeable Transfer Learning for Cross-Lingual Machine Reading Comprehension
In cross-lingual language understanding, machine translation is often
utilized to enhance the transferability of models across languages, either by
translating the training data from the source language to the target, or from
the target to the source to aid inference. However, in cross-lingual machine
reading comprehension (MRC), it is difficult to perform a deep level of
assistance to enhance cross-lingual transfer because of the variation of answer
span positions in different languages. In this paper, we propose X-STA, a new
approach for cross-lingual MRC. Specifically, we leverage an attentive teacher
to subtly transfer the answer spans of the source language to the answer output
space of the target. A Gradient-Disentangled Knowledge Sharing technique is
proposed as an improved cross-attention block. In addition, we force the model
to learn semantic alignments from multiple granularities and calibrate the
model outputs with teacher guidance to enhance cross-lingual transferability.
Experiments on three multi-lingual MRC datasets show the effectiveness of our
method, outperforming state-of-the-art approaches.Comment: emnlp 202
Schrodinger Bridges Beat Diffusion Models on Text-to-Speech Synthesis
In text-to-speech (TTS) synthesis, diffusion models have achieved promising
generation quality. However, because of the pre-defined data-to-noise diffusion
process, their prior distribution is restricted to a noisy representation,
which provides little information of the generation target. In this work, we
present a novel TTS system, Bridge-TTS, making the first attempt to substitute
the noisy Gaussian prior in established diffusion-based TTS methods with a
clean and deterministic one, which provides strong structural information of
the target. Specifically, we leverage the latent representation obtained from
text input as our prior, and build a fully tractable Schrodinger bridge between
it and the ground-truth mel-spectrogram, leading to a data-to-data process.
Moreover, the tractability and flexibility of our formulation allow us to
empirically study the design spaces such as noise schedules, as well as to
develop stochastic and deterministic samplers. Experimental results on the
LJ-Speech dataset illustrate the effectiveness of our method in terms of both
synthesis quality and sampling efficiency, significantly outperforming our
diffusion counterpart Grad-TTS in 50-step/1000-step synthesis and strong fast
TTS models in few-step scenarios. Project page: https://bridge-tts.github.io
A fast pruned‐extreme learning machine for classification problem
Agency for Science, Technology and Research (A*STAR) Science and Engineering Research Counci
Ethyl 2-(3-chloro-2-pyridyl)-5-oxopyrazolidine-3-carboxylate
In the molecule of the title compound, C11H12ClN3O3, the five membered ring adopts an envelope conformation. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers
Activation of an AMP-activated protein kinase is involved in post-diapause development of Artemia franciscana encysted embryos
<p>Abstract</p> <p>Background</p> <p>Cysts of <it>Artemia </it>can remain in a dormant state for long periods with a very low metabolic rate, and only resume their development with the approach of favorable conditions. The post-diapause development is a very complicated process involving a variety of metabolic and biochemical events. However, the intrinsic mechanisms that regulate this process are unclear.</p> <p>Results</p> <p>Herein we report the specific activation of an AMP-activated protein kinase (AMPK) in the post-diapause developmental process of <it>Artemia</it>. Using a phospho-AMPKα antibody, AMPK was shown to be phosphorylated in the post-diapause developmental process. Results of kinase assay analysis showed that this phosphorylation is essential for AMPK activation. Using whole-mount immunohistochemistry, phosphorylated AMPK was shown to be predominantly located in the ectoderm of the early developed embryos in a ring shape; however, the location and shape of the activation region changed as development proceeded. Additionally, Western blotting analysis on different portions of the cyst extracts showed that phosphorylated AMPKα localized to the nuclei and this location was not affected by intracellular pH. Confocal microscopy analysis of immunofluorescent stained cyst nuclei further showed that AMPKα localized to the nuclei when activated. Moreover, cellular AMP, ADP, and ATP levels in developing cysts were determined by HPLC, and the results showed that the activation of <it>Artemia </it>AMPK may not be associated with cellular AMP:ATP ratios, suggesting other pathways for regulation of <it>Artemia </it>AMPK activity.</p> <p>Conclusion</p> <p>Together, we report evidence demonstrating the activation of AMPK in <it>Artemia </it>developing cysts and present an argument for its role in the development-related gene expression and energy control in certain cells during post-diapause development of <it>Artemia</it>.</p
Ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate
The title compound, C11H9BrClN3O2, is an intermediate in the synthesis of Rynaxypyre, a new insecticidal anthranilic diamide used as a potent and selective ryanodine receptor activator. The dihedral angle between the aromatic ring planes is 78.7 (2)°
H2S Donor, S-Propargyl-Cysteine, Increases CSE in SGC-7901 and Cancer-Induced Mice: Evidence for a Novel Anti-Cancer Effect of Endogenous H2S?
Background: S-propargyl-cysteine (SPRC), an H2S donor, is a structural analogue of S-allycysteine (SAC). It was investigated for its potential anti-cancer effect on SGC-7901 gastric cancer cells and the possible mechanisms that may be involved. Methods and Findings: SPRC treatment significantly decreased cell viability, suppressed the proliferation and migration of SPRC-7901 gastric cancer cells, was pro-apoptotic as well as caused cell cycle arrest at the G 1/S phase. In an in vivo study, intra-peritoneal injection of 50 mg/kg and 100 mg/kg of SPRC significantly reduced tumor weights and tumor volumes of gastric cancer implants in nude mice, with a tumor growth inhibition rate of 40–75%. SPRC also induced a pro-apoptotic effect in cancer tissues and elevated the expressions of p53 and Bax in tumors and cells. SPRC treatment also increased protein expression of cystathione-c-lyase (CSE) in cells and tumors, and elevated H 2S levels in cell culture media, plasma and tumoral CSE activity of gastric cancer-induced nude mice by 2, 2.3 and 1.4 fold, respectively. Most of the anti-cancer functions of SPRC on cells and tumors were significantly suppressed by PAG, an inhibitor of CSE activity. Conclusions: Taken together, the results of our study provide insights into a novel anti-cancer effect of H2S as well as o
Bidirectional correlation between gastroesophageal reflux disease and sleep problems: a systematic review and meta-analysis
Objectives Gastroesophageal reflux disease (GERD) and sleep problems are highly prevalent among the general population. Both them are associated with a variety of psychiatric disorders such as depression and anxiety, which is highlighting an underexplored connection between them. This meta-analysis aims to explore the association between sleep problems and GERD. Methods We conducted a comprehensive search on PubMed, Cochrane Library, Embase, and Web of Science, using Medical Subject Headings (MeSH) and keywords, covering articles from the inception of the databases until August 2023. Stata statistical software, version 14.0, was utilized for all statistical analyses. A fixed-effects model was applied when p > 0.1 and I2 ≤ 50%, while a random-effects model was employed for high heterogeneity (p 50%). Funnel plots and Egger’s test were used to assess publication bias. Results Involving 22 studies, our meta-analysis revealed that insomnia, sleep disturbance, or short sleep duration significantly increased the risk of GERD (OR = 2.02, 95% CI [1.64–2.49], p < 0.001; I2 = 66.4%; OR = 1.98, 95% CI [1.58–2.50], p < 0.001, I2 = 50.1%; OR = 2.66, 95% CI [2.02–3.15], p < 0.001; I2 = 62.5%, respectively). GERD was associated with an elevated risk of poor sleep quality (OR = 1.47, 95% CI [1.47–1.79], p < 0.001, I2 = 72.4%), sleep disturbance (OR = 1.47, 95% CI [1.24–1.74], p < 0.001, I2 = 71.6%), or short sleep duration (OR = 1.17, 95% CI [1.12–1.21], p < 0.001, I2 = 0). Conclusion This meta-analysis establishes a bidirectional relationship between four distinct types of sleep problems and GERD. The findings offer insights for the development of innovative approaches in the treatment of both GERD and sleep problems
Prognostic significance of hemoglobin A1c level in patients hospitalized with coronary artery disease. A systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>The prognostic value of hemoglobin A1c (HbA1c) in coronary artery disease (CAD) remains controversial. Herein, we conducted a systematic review to quantify the association between elevated HbA1c levels and all-cause mortality among patients hospitalized with CAD.</p> <p>Methods</p> <p>A systematic search of electronic databases (PubMed, EMBASE, OVID, Web of Science, The Cochrane Library) for studies published from 1970 to May 2011 was performed. Cohort, case-control studies, and randomized controlled trials that examined the effect of HbA1c on all-cause mortality were included.</p> <p>Results</p> <p>Twenty studies met final inclusion criteria (total n = 13, 224). From the pooled analyses, elevated HbA1c level was significantly associated with increased short-term (OR 2.32, 95% CI, 1.61 to 3.35) and long-term (OR 1.54, 95% CI, 1.23 to 1.94) mortality risk. Subgroup analyses suggested elevated HbA1c level predicted higher mortality risk in patients without diabetes (OR 1.84, 95% CI, 1.51 to 2.24). In contrast, in patients with diabetes, elevated HbA1c level was not associated with increased risk of mortality (OR 0.95, 95% CI, 0.70 to 1.28). In a risk-adjusted sensitivity analyses, elevated HbA1c was also associated with a significantly high risk of adjusted mortality in patients without diabetes (adjusted OR 1.49, 95% CI, 1.24 to 1.79), but had a borderline effect in patients with diabetes (adjusted OR 1.05, 95% CI, 1.00 to 1.11).</p> <p>Conclusions</p> <p>Our findings demonstrate that elevated HbA1c level is an independent risk factor for mortality in CAD patients without diabetes, but not in patients with established diabetes. Prospective studies should further investigate whether glycemic control might improve outcomes in CAD patients without previously diagnosed diabetes.</p
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