Asynchronous Training of Word Embeddings for Large Text Corpora

Word embeddings are a powerful approach for analyzing language and have been widely popular in numerous tasks in information retrieval and text mining. Training embeddings over huge corpora is computationally expensive because the input is typically sequentially processed and parameters are synchronously updated. Distributed architectures for asynchronous training that have been proposed either focus on scaling vocabulary sizes and dimensionality or suffer from expensive synchronization latencies. In this paper, we propose a scalable approach to train word embeddings by partitioning the input space instead in order to scale to massive text corpora while not sacrificing the performance of the embeddings. Our training procedure does not involve any parameter synchronization except a final sub-model merge phase that typically executes in a few minutes. Our distributed training scales seamlessly to large corpus sizes and we get comparable and sometimes even up to 45% performance improvement in a variety of NLP benchmarks using models trained by our distributed procedure which requires $1/10$ of the time taken by the baseline approach. Finally we also show that we are robust to missing words in sub-models and are able to effectively reconstruct word representations.Comment: This paper contains 9 pages and has been accepted in the WSDM201

Unprecedented stereoselective synthesis of 3-methylisoxazolidine-5-aryl-1,2,4-oxadiazoles via 1,3-dipolar cycloadditions and study of their in vitro antioxydant activity

International audienceThe stereoselective 1,3-dipolar cycloaddition between allyl cyanide and a menthone-derived nitrone led to the desired isoxazolidine in good yield. Once the nitrile group transformed to an amidoxime group, the cyclocondensation of various aldehydes with chiral amidoxime led to unprecedented enantiopure 3-methylisoxazolidine-5-aryl-1,2,4-oxadiazoles. The menthone chiral auxiliary was then removed with acid hydrolysis. The new compounds were also screened for their in vitro antioxidant activity using DPPH and FRAP assays. Some of the compounds showed promising antioxidant activity

Utilisation des représentations continues des mots et des paramètres prosodiques pour la détection des erreurs dans les transcriptions automatiques de la parole

International audienc

Phytochemical Profiling of Allium subhirsutum L. Aqueous Extract with Antioxidant, Antimicrobial, Antibiofilm, and Anti-Quorum Sensing Properties: In Vitro and In Silico Studies

The present study was the first to evaluate the phytochemical composition, antioxidant, antimicrobial, antibiofilm, and anti-quorum sensing potential of Allium subhirsutum L. (hairy garlic) aqueous extract through in vitro and in silico studies. The phytochemical profile revealed the pres-ence of saponins, terpenes, flavonols/flavonones, flavonoids, and fatty acids, particularly with flavonoids (231 ± 0.022 mg QE/g extract), tannins (159 ± 0.006 mg TAE/g extract), and phenols (4 ± 0.004 mg GAE/g extract). Gas chromatography–mass spectrometry (GC–MS) analysis identified 15 bioactive compounds, such as 5-hydroxymethylfurfural (37.04%), methyl methanethiolsulfonate (21.33%), furfural (7.64%), beta-D-glucopyranose, 1,6-anhydro-(6.17%), 1,6-anhydro-beta-D-gluco-furanose (3.6%), trisulfide, di-2-propenyl (2.70%), and diallyl disulfide (1.93%). The extract was found to be non-toxic with 50% cytotoxic concentration higher than 30,000 µg/mL. The investigation of the antioxidant activity via DPPH (2, 2-diphenyl-1-picrylhydrazyl) and FRAP (IC50 = 1 μg/mL), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); IC50 = 0.698 ± 0.107 μg/mL), and β-car-otene (IC50 = 0.811 ± 0.036 mg/mL) was assessed. Nevertheless, good antimicrobial potential against a diverse panel of microorganisms with bacteriostatic and fungistatic effect was observed. Quorum sensing inhibition effects were also assessed, and the data showed the ability of the extract to inhibit the production of violacein by the mutant C. violaceum strain in concentration-dependent manner. Similarly, the biofilm formation by all tested strains was inhibited at low concentrations. In silico pharmacokinetic and toxicological prediction indicated that, out of the sixteen identified compounds, fourteen showed promising drug ability and could be used as lead compounds for further development and drug design. Hence, these findings support the popular use of hairy garlic as a source of bioactive compounds with potential application for human health