Search results for " BIA"

showing 10 items of 529 documents

Biodiversity dynamics and their driving factors during the Cretaceous diversification of Spatangoida (Echinoidea, Echinodermata)

2004

Abstract Variations in recorded diversity over time present a scrambled signal that is modulated by a large number of variables: the potential of particular life forms to generate evolutionary innovations, external constraints induced by the environment in its broad sense, the heterogeneity of the fossil record and the analytical artefacts due to sampling bias. A key question is how to characterise and quantify the separate input of any given factor in the overall diversity signal. This paper explores the structure of diversity data for spatangoid heart urchins and the sensitivity of recorded diversity to different factors of analytical bias (length of geological periods, proportion of pala…

SpatangoidabiologyPhylogenetic treeEcologyBiodiversityPaleontologyrespiratory systemDiversification (marketing strategy)Oceanographybiology.organism_classificationPaleontologyhuman activitiesOriginationEcology Evolution Behavior and SystematicsEarth-Surface ProcessesGlobal biodiversitySampling biasDiversity (business)Palaeogeography, Palaeoclimatology, Palaeoecology
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ASYMMETRY OF SELECTIVE ATTENTION IN HEALTHY SUBJECTS AND PATIENTS WITH CERVICAL FOCAL DYSTONIA

The environment continuously provides a wealth of information through our senses. This poses a major challenge to our brains to effectively process the relevant pieces of information over space and time, involving attentional processes. Attention selects, modulates and sustains focus on information most relevant for behaviour going beyond our limited capacity to process competing options. Voluntary allocation of attention to features, objects, or regions in space is controlled by top-down mechanisms. On the other hand, salient stimuli can automatically attract attention, even though the subject does not have intentions to attend to these stimuli. A key question is how attention is shaped by…

Spatial processingCervical DystoniaTemporal processingVisuo and Audio domainsSettore M-PSI/02 - Psicobiologia E Psicologia FisiologicaVisuo-audio domainAttantional bias
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Multi-site analytical evaluation of a chemiluminescent magnetic microparticle immunoassay (CMIA) for sirolimus on the Abbott ARCHITECT analyzer.

2009

Objective This study evaluated a new chemiluminescent magnetic microparticle immunoassay (CMIA) for sirolimus on the ARCHITECT analyzer. Design and methods Patient and laboratory proficiency samples were tested at three European sites and one site in the United States. Results The CMIA total %CV's were all < 8% and the Limit of Quantification (LOQ) was < 1.52 ng/mL across the four sites. It cross-reacts to sirolimus metabolites F4 and F5 and showed no hematocrit interference over a range of 25% to 55%. Patient specimen correlations to three LC/MS/MS methods gave R ≥ 0.91 at three sites and mean biases of 14%, 25% and 39%. CMIA patient specimen correlations to the Abbott IMx gave R ≥ 0.94 at…

Spectrum analyzerClinical BiochemistryHematocritSensitivity and Specificitylaw.inventionMagneticslawAntibody SpecificityTandem Mass SpectrometrymedicineHumansParticle SizeChemiluminescenceDetection limitImmunoassaySirolimusChromatographymedicine.diagnostic_testChemistryMulti siteGeneral MedicineImmunoassay methodImmunoassayLuminescent MeasurementsPositive biasImmunosuppressive AgentsChromatography LiquidClinical biochemistry
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On the ambiguous consequences of omitting variables

2015

This paper studies what happens when we move from a short regression to a long regression (or vice versa), when the long regression is shorter than the data-generation process. In the special case where the long regression equals the data-generation process, the least-squares estimators have smaller bias (in fact zero bias) but larger variances in the long regression than in the short regression. But if the long regression is also misspecified, the bias may not be smaller. We provide bias and mean squared error comparisons and study the dependence of the differences on the misspecification parameter.

Statistics::TheoryMean squared errorjel:C52Regression dilutionjel:C51Local regressionjel:C13Regression analysisOmitted-variable biasCross-sectional regressionStatistics::ComputationOmitted variables Misspecification Least-squares estimators Bias Mean squared errorStatistics::Machine LearningStatisticsEconometricsStatistics::MethodologyRegression diagnosticNonlinear regressionMathematics
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tBuLi-Mediated One-Pot Direct Highly Selective Cross-Coupling of Two Distinct Aryl Bromides.

2015

A Pd-catalyzed direct cross-coupling of two distinct aryl bromides mediated by tBuLi is described. The use of [Pd-PEPPSI-IPr] or [Pd-PEPPSI-IPent] as catalyst allows for the efficient one-pot synthesis of unsymmetrical biaryls at room temperature. The key for this selective cross-coupling is the use of an ortho-substituted bromide that undergoes lithium-halogen exchange preferentially.

Stereochemistry22'-BIPYRIDINE COMPLEX2chemistry.chemical_elementORGANOLITHIUM COMPOUNDSCatalysisCatalysischemistry.chemical_compoundLOW-TEMPERATUREBromideOrganolithium compoundscross-couplingN-heterocyclic carbenesGRIGNARD-REAGENTSPD-PEPPSI-IPENT2'-BIPYRIDINE COMPLEXCARBON BOND FORMATIONArylOrganic ChemistryORGANIC-SYNTHESISGeneral ChemistryORTHO-SUBSTITUTED BIARYLSpalladiumHighly selectiveCombinatorial chemistryFUNCTIONALIZED ARYLCoupling (electronics)biarylschemistrylithiumOrganic synthesisUNSYMMETRICAL BIARYLSPalladiumChemistry (Weinheim an der Bergstrasse, Germany)
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Reassessing the evidence for tree-growth and inferred temperature change during the Common Era in Yamalia, northwest Siberia

2013

AbstractThe development of research into the history of tree growth and inferred summer temperature changes in Yamalia spanning the last 2000 years is reviewed. One focus is the evolving production of tree-ring width (TRW) and tree-ring maximum-latewood density (MXD) larch (Larix sibirica) chronologies, incorporating different applications of Regional Curve Standardisation (RCS). Another focus is the comparison of independent data representing past tree growth in adjacent Yamalia areas: Yamal and Polar Urals, and the examination of the evidence for common growth behaviour at different timescales. The sample data we use are far more numerous and cover a longer time-span at Yamal compared to …

Summer temperatureArcheologyGlobal and Planetary ChangebiologyYamalDendroclimatologyClimate reconstructionGeologyDendroclimatologyMedieval Warm Periodbiology.organism_classificationTree (graph theory)Larix sibiricaClimatologyLarchPolar UralsIndependent dataMedieval warm periodGeologyEcology Evolution Behavior and SystematicsChronologySampling biasQuaternary Science Reviews
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Scanning tunneling measurements of layers of superconducting 2H-TaSe2: Evidence for a zero-bias anomaly in single layers

2013

This work was supported by the EU (ERC Advanced Grant SPINMOL and COST MP-1201), the Spanish MINECO (Consolider-Ingenio in Molecular Nanoscience, CSD2007-00010 and projects FIS2011-23488, MAT2011-25046, MAT2011-22785 and ACI-2009-0905, co-financed by FEDER), by the Comunidad de Madrid (program Nanobiomagnet) and the Generalitat Valenciana (Programs Prometeo and ISIC-NANO)

SuperconductivityPhysicsCondensed matter physicsNanotechnology02 engineering and technology021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesElectronic Optical and Magnetic Materials0103 physical sciencesZero biasAnomaly (physics)010306 general physics0210 nano-technologyQuantum tunnellingPhysical Review B
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The dynamics of magnetic ordering in a natural hemo-ilmenite solid solution

2007

Geophysical Journal International, 169 (3)

Superparamagnetic clustersHemo-ilmeniteMaterials scienceSolid solutionAnalytical chemistryAtmospheric temperature rangeengineering.materialExchange anisotropyEnvironmental magnetism; Exchange anisotropy; Hemo-ilmenite; Low-temperature magnetism; Solid solution; Superparamagnetic clustersCrystallographyMagnetizationEnvironmental magnetismGeophysicsExchange biasGeochemistry and PetrologyFerrimagnetismengineeringAntiferromagnetismLow-temperature magnetismIlmeniteSolid solutionSuperparamagnetismGeophysical Journal International
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Improving predictive accuracy of exit polls

2010

Abstract Exit polls are best known for their use in election forecasting. In recent years, however, some prominent mistaken predictions have been made, undermining public confidence in the accuracy of both exit polls and survey methods. Nonresponse bias has been claimed as being one of the main reasons for inaccurate projections. Traditionally, the issue has been handled through an age–race–sex adjustment at the national and state levels. An alternative solution is suggested and detailed in this paper. A two-step strategy is proposed to reduce nonresponse bias and improve predictions. First, “vote-remembering” (vote recall) is used to correct party proportion estimates at polling locations;…

Survey methodologyComputer scienceVotingmedia_common.quotation_subjectPrecinctPublic confidenceEconometricsSurvey samplingNon-response biasBusiness and International ManagementPollingRaw datamedia_commonInternational Journal of Forecasting
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Serenet, Bigotudo (VER0000017)

Altres noms vulgars: Bearded Parrotbill (Anglès), Panure à moustaches (Francès), Bartmeise (Alemany) Gabinet de Vertebrats (Departament de Zoologia), Facultat de Ciències Biològiques (Campus de Burjassot), C/ Doctor Moliner, s/n, Bloque B. 5é plant, Burjassot (Valencia). Armari: 24-2 La Albufera Macho

SylviidaePanurus biarmicus (Linnaeus 1758)Pájaros
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