Search results for "Extraction"

Mutual information-based feature selection for low-cost BCIs based on motor imagery

2016

In the present study a feature selection algorithm based on mutual information (MI) was applied to electro-encephalographic (EEG) data acquired during three different motor imagery tasks from two dataset: Dataset I from BCI Competition IV including full scalp recordings from four subjects, and new data recorded from three subjects using the popular low-cost Emotiv EPOC EEG headset. The aim was to evaluate optimal channels and band-power (BP) features for motor imagery tasks discrimination, in order to assess the feasibility of a portable low-cost motor imagery based Brain-Computer Interface (BCI) system. The minimal sub set of features most relevant to task description and less redundant to…

Design and performance testing of a real-time PCR assay for sensitive and reliable direct quantification of Brettanomyces in wine

2009

International audience; Because the yeast Brettanomyces produces volatile phenols and acetic acid, it is responsible for wine spoilage. The uncontrolled accumulation of these molecules in wine leads to sensorial defects that compromise wine quality, The need for a rapid, specific, sensitive and reliable method to detect this spoilage yeast has increased over the last decade. All these requirements are met by real-time PCR. We here propose improvements of existing methods to enhance the robustness of the assay. Six different protocols to isolate DNA from a wine and three PCR mix compositions were tested, and the best method was selected. Insoluble PVPP addition during DNA extraction by a cla…

Investigation of sterols as potential biomarkers for the detection of pig (S. s. domesticus) decomposition fluid in soils

2012

This study was carried out to evaluate the potential of using cholesterol and coprostanol, as indicators for the detection of decomposition fluid of buried pigs (S. s. domesticus) in soils. In May 2007, four pig carcasses (~35. kg) were buried in shallow graves (~40. cm depth) at the University of Ontario Institute of Technology in Canada. Two pigs were exhumed after three months (Pig 1, Pig 2) and six months (Pig 3, Pig 4) post burial. Soil samples were collected beneath the pig carcasses (~40. cm depth) and from grave walls (~15-20. cm depth) as well as from a parallel control site. Coprostanol and cholesterol were extracted from soils, purified with solid phase extraction (SPE) and analy…

Human-in-the-Loop Conversation Agent for Customer Service

2020

This paper describes a prototype system for partial automation of customer service operations of a mobile telecommunications operator with a human-in-the loop conversational agent. The agent consists of an intent detection system for identifying the types of customer requests that it can handle appropriately, a slot filling information extraction system that integrates with the customer service database for a rule-based treatment of the common scenarios, and a template-based language generation system that builds response candidates that can be approved or amended by customer service operators. The main focus of this paper is on the system architecture and machine learning system structure …

ImageRover: A Content-Based Image Browser for the World Wide Web

1997

ImageRover is a search-by-image-content navigation tool for the World Wide Web (WWW). To gather images expediently, the image collection subsystem utilizes a distributed fleet of WWW robots running on different computers. The image robots gather information about the images they find, computing the appropriate image decompositions and indices, and store this extracted information in vector form for searches based on image content. At search time, users can iteratively guide the search through the selection of relevant examples. Search performance is made efficient through the use of an approximate, optimized k-d tree algorithm. The system employs a novel relevance feedback algorithm that se…

ANTIPROLIFERATIVE ACTIVITY OF CYSTOSEIRA FOENICULACEA SFE EXTRACT ON HEPG2 CELL LINE.

2008

Simultaneous determination of eight underivatised biogenic amines in fish by solid phase extraction and liquid chromatography-tandem mass spectrometr…

2010

Biogenic amines on fish tissue are formed as a result of bacterial contamination and spoilage during storage. A new method based on liquid chromatography (LC) and tandem mass spectrometry (MS/MS) using a triple quadrupole (QqQ) analyser was developed for the analysis of eight biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermine, spermidine, tyramine and tryptamine) in fish tissues. Sample preparation was performed by extraction with trichloroacetic acid 5% and solid phase extraction clean up with STRATA X cartridge. The MS/MS method was validated and compared with a method based on the analysis of dansyl derivatives by LC and fluorescence detector (FD). MS/MS achie…

Ultrasound-assisted sequential extraction method for the evaluation of mobility of toxic elements in contaminated soils

2005

A method for the fast sequential extraction of toxic elements in contaminated soil samples using an ultrasonic water bath, followed by determination with inductively coupled plasma optical emission spectrometry (ICP-OES), was developed and compared with other methods introduced in the literature. The five-step sequential extraction (Tessier scheme) was shortened using ultrasound-assisted sequential extraction (UASE). The optimization of the five-step sequential extraction was based on the analysis of SRM 2710 using Tessiers’s method as a reference. Several extracting solutions with different sonication times and temperatures were tested in the optimization procedure. Concentrations of arsen…

In-situ suspended aggregate microextraction: A sample preparation approach for the enrichment of organic compounds in aqueous solutions.

2015

Abstract This work presents in-situ suspended aggregate microextraction (iSAME) as a new and expedient sample preparation method. This new concept capitalizes on the general principles of in-situ solvent formation microextraction, in the sense that extraction is carried out in a supramolecular aggregate phase, which is formed in-situ in the sample through one-step process involving ion-association between a cationic surfactant and a benzene sulfonic acid derivative. The suspended aggregate containing the analytes is then collected in the form of a thin-film on the surface of a common filter paper by suction filtration. The entrapped analytes are released by completely dissolving the thin-fi…

Application of integrative cloud point extraction and concentration for the analysis of polyphenols and alkaloids in mulberry leaves

2018

Abstract A simple and efficient method based on cloud point extraction and concentration combined with high performance liquid chromatography was developed for the simultaneous separation and determination of five target compounds (deoxynojirimycin, chlorogenic acid, rutin, isoquercitrin and astragalin) in mulberry leaves samples. Firstly, to obtain a high extraction rate, the ultrasound assisted extraction was developed on acid modified Triton X-114 system. Under the optimal conditions, the total maximum extraction yields of five target compounds reached 20.80 mg/g, which was superior to conventional solvent extraction. After the cloud point extraction and concentration, the HPLC analysis …