Search results for " sample"

showing 10 items of 456 documents

On implementation of the Gibbs sampler for estimating the accuracy of multiple diagnostic tests

2010

Implementation of the Gibbs sampler for estimating the accuracy of multiple binary diagnostic tests in one population has been investigated. This method, proposed by Joseph, Gyorkos and Coupal, makes use of a Bayesian approach and is used in the absence of a gold standard to estimate the prevalence, the sensitivity and specificity of medical diagnostic tests. The expressions that allow this method to be implemented for an arbitrary number of tests are given. By using the convergence diagnostics procedure of Raftery and Lewis, the relation between the number of iterations of Gibbs sampling and the precision of the estimated quantiles of the posterior distributions is derived. An example conc…

Statistics and Probabilityeducation.field_of_studygastroesophageal reflux diseaseBayesian probabilityPopulationGold standard (test)Settore FIS/03 - Fisica Della MateriaGibbs sampler; Bayesian analysis; convergence diagnostics; diagnostic tests; gastroesophageal reflux diseaseSettore MED/01 - Statistica MedicaData setsymbols.namesakediagnostic testGibbs samplerConvergence (routing)Statisticsconvergence diagnosticsymbolsSensitivity (control systems)Statistics Probability and UncertaintyeducationAlgorithmBayesian analysiQuantileMathematicsGibbs samplingJournal of Applied Statistics
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Visualization in comparative music research

2007

Computational analysis of large musical corpora provides an approach that overcomes some of the limitations of manual analysis related to small sample sizes and subjectivity. The present paper aims to provide an overview of the computational approach to music research. It discusses the issues of music representation, musical feature extraction, digital music collections, and data mining techniques. Moreover, it provides examples of visualization of large musical collections.

SubjectivityInformationSystems_INFORMATIONINTERFACESANDPRESENTATION(e.g.HCI)Computer sciencebusiness.industryFeature extractionRepresentation (systemics)Small sampleMusicalcomputer.software_genreVisualizationComputational musicologyArtificial intelligencebusinesscomputerNatural language processingDigital audio
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GHB related acids are useful in routine casework of suspected GHB intoxication cases

2021

Abstract GHB related acids (3,4-dihydroxy butyric acid, 2,4-dihydroxy butyric acid and glycolic acid) are produced through oxidative GHB metabolism. These analytes could be potential biomarkers to ensure the diagnosis of a GHB intoxication and even prolong the detection window. Within this study, forensic routine cases were measured to consider the potential of additional gas chromatographic mass spectrometric analysis on these acids. 17 GHB positive real cases (10 serum samples and 7 urine samples) and 40 cases with suspicion of drugging in DFC cases and negative GHB results (21 serum samples and 19 urine samples) were evaluated. Increased GHB related acid concentrations were detected in a…

Succinic AcidUrinePharmacology01 natural sciencesGas Chromatography-Mass SpectrometryPathology and Forensic MedicineButyric acidForensic Toxicology03 medical and health scienceschemistry.chemical_compoundα oxidation0302 clinical medicineHumansMedicine030216 legal & forensic medicineGlycolic acidbusiness.industryPoisoning010401 analytical chemistrySerum samplesMass spectrometricGlycolates0104 chemical scienceschemistryPotential biomarkersButyric AcidSodium OxybatebusinessLawBiomarkersForensic Science International
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La Valle dei Templi in epoca medioevale. Caratterizzazione antropologica e paleopatologica delle sepolture antistanti in Tempio della Concordia

2021

Riassunto ― Il lavoro presenta i risultati delle analisi bio-archeologiche effettuate su resti scheletrici umani rinvenuti in quattordici sepolture di epoca medioevale rinvenute nel Parco Archeologico della Valle dei Templi di Agrigento (Sicilia). L’obiettivo è stato l’acquisizione delle informazioni necessarie per la ricostruzione del profilo biologico di ciascun individuo, al fine di determinarne il sesso, la stima dell’età biologica alla morte, la stima della statura e la valutazione delle patologie e degli indicatori di stress occupazionale mediante le correnti metodologie e tecniche diagnostiche di tipo antropologico. Sebbene il cattivo stato di conservazione di alcuni individui non ne…

Summary ― The work presents the results of the bio-archaeological analyzes carried out on human skeletal remains found in fourteen burials of Medieval chronology at the Archaeological Park of Valle dei Templi in Agrigentum (Sicily). The aim of the work was the acquisition of the information necessary for the reconstruction of the biological profile of each individual throught the determination of sex the estimate of the biological age at death the estimate of height and the evaluation of pathologies and markers of occupational stress through current anthropological diagnostic methodologies and techniques. Althought the poor state of conservation of some individuals has not allowed their whole anthropological characterization the investigations have highlighted the heterogeneity relating to the age groups and have allowed us to ascertain the presence of pathological alterations in subjects of mature age sometimes of unknown etiology such as DISH (Diffuse Idiopathic Hyperostosis). The sample size is not representative of the entire population but subsequent insights will provide a better understanding of the population dynamics of Medieval Agrigentum.Settore BIO/08 - Antropologia
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Anomalous magnetic hysteresis in the microwave surface resistance of MgB2 superconductor

2007

We report experimental results of the field-induced variations of the microwave surface resistance in samples of MgB2, produced by different methods. By sweeping the DC magnetic field at increasing and decreasing values, we have detected a magnetic hysteresis that can be ascribed to the different magnetic induction, due to the critical state of the fluxon lattice. The hysteresis observed in the bulk samples has an unusual shape, which cannot be justified in the framework of the critical-state models.

SuperconductivitySuperconductivityHistoryMicrowave surface resistanceMaterials scienceCondensed matter physicsFluxonMgB2Condensed Matter - SuperconductivitySettore FIS/01 - Fisica SperimentaleFOS: Physical sciencesMagnetic hysteresismicrowave surface impedanceComputer Science ApplicationsEducationElectromagnetic inductionMagnetic fieldSuperconductivity (cond-mat.supr-con)Lattice (order)Bulk samplesCondensed Matter::Superconductivity
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Properties of Swift's intermediate bursts

2011

Based on their prompt, high-energy emission, gamma-ray bursts are usually classified into short-duration and long-duration classes. A third intermediate group has been identified on statistical grounds but its individual properties have not yet been studied in detail. Using the large sample of follow-up observations of GRBs produced during the Swift era we analyze the individual characteristics of this group. We find that intermediate bursts are significantly different from short GRBs but share many properties with long bursts, probably pointing to a common progenitor type. However, we find that intermediate bursts are significantly dimmer and have on average lower redshifts. Based on their…

SwiftPhysicsAstrophysics::High Energy Astrophysical PhenomenaGamma rayAstronomyAstrophysicsRedshiftLarge sampleIntermediate groupFIS/05 - ASTRONOMIA E ASTROFISICAredshift gamma-rays brightness spectral analysisgamma-ray sources (astronomical) brightness X-ray sources (astronomical)Spectral analysisGamma-ray burstcomputercomputer.programming_language
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Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samp…

2021

In the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application of molecularly imprinted polymers (MIPs) is gaining greater popularity. It is mainly related to their physicochemical properties, sorption capacity and selectivity, thermo-mechanical resistance, as well as a wide range of polymerization techniques allowing to obta…

TechnologyMultivariate statisticsSample (statistics)molecularly imprinted polymers; pesticides; environmental samples; agricultural samples; multi-criteria decision analysisArticleenvironmental samplesagricultural samplesGeneral Materials ScienceSample preparationProcess engineeringMicroscopyQC120-168.85business.industryTQH201-278.5Extraction (chemistry)Molecularly imprinted polymerSorptionpesticidesPesticideEngineering (General). Civil engineering (General)multi-criteria decision analysisTK1-9971Descriptive and experimental mechanicsmolecularly imprinted polymersEnvironmental scienceAnalytical proceduresElectrical engineering. Electronics. Nuclear engineeringTA1-2040businessMaterials
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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(Supplementary Table 1) 230Th/U results for stalagmite Cuba Grande (CG) from Pinar del Rio

2010

We present 22 U-series ages for a stalagmite from north-western Cuba based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and thermal ionisation mass spectrometry (TIMS). Our results reveal that the stalagmite continuously grew within the last ~1400a. Low uranium content of the sample and thus, extremely low 230Th concentrations limit the precision and accuracy of 230Th/U-dating by TIMS. Samples measured by MC-ICPMS show a high variability of 232Th content along the growth axis with some sections significantly affected by initial 230Th from a detrital phase. An a-priori bulk earth ratio for (238U/232Th) cannot be used to accurately account for this initial 230Th.…

Thorium 230 Uranium 238 ratioUranium-234 standard deviationIntegrierte Analyse zwischeneiszeitlicher Klimadynamik INTERDYNAMIKUranium 238Thorium 230 Uranium 238 activity ratioUranium-238Thorium-230/Uranium-238 activity ratio standard deviationAge commentUranium 234Integrierte Analyse zwischeneiszeitlicher Klimadynamik (INTERDYNAMIK)commentAge dateddateddated standard deviationAgeAge dated standard deviationThorium-232 standard deviationThorium-230/Uranium-238 ratioMulti collector inductively coupled plasma mass spectrometer MC ICP MSThorium-230/Thorium-232 activity ratioThorium 232Uranium-238 standard deviationSpeleothem sampleThorium 230 Thorium 232 activity ratioUranium-234/Uranium-238 activity ratioUranium 234 Uranium 238 activity ratioThorium-232DISTANCEEarth System ResearchMulti-collector inductively coupled plasma mass spectrometer (MC-ICP-MS)standard deviationThorium-230/Thorium-232 activity ratio standard deviation
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Minimal exposure time of different LED-curing devices

2007

Abstract Objectives The purpose of the study was to investigate the shortest possible exposure time of different LED-curing devices for five different resin composites in a clinically relevant in vitro-model, where a 7 mm distance from the light guide tip to the bottom side of the cavity was compiled. Methods Resin composite samples (Tetric EvoCeram A3, Filtek Supreme XT A3B, Premise A3, CeramX Mono M5, QuiXfil) were filled in three increments of 2 mm thickness each in stainless steel moulds (O = 5 mm, h  = 6 mm, n  = 9). The samples were incrementally exposed to different blue LED-curing devices (Bluephase, Bluephase C8, Bluephase 16i/Ivoclar Vivadent, L.E.Demetron II/sds Kerr, Elipar Free…

Time FactorsMaterials scienceLightSurface PropertiesHardness ratioResin compositeComposite numberLight guideEquipment DesignComposite ResinsHardnessTetric EvoCeramDental MaterialsReference sampleHardnessMechanics of MaterialsMaterials TestingHumansGeneral Materials ScienceComposite materialGeneral DentistryLightingCuring (chemistry)Dental Materials
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