Search results for "Planar"

showing 10 items of 412 documents

ErbB4 genotype predicts left frontotemporal structural connectivity in human brain.

2008

Diminished left frontotemporal connectivity is among the most frequently reported findings in schizophrenia and there is evidence that altered neuronal myelination may in part account for this deficit. Several investigations have suggested that variations of the genes that encode the Neuregulin 1 (NRG1)-ErbB4 receptor complex are associated with schizophrenia illness. As NRG1--ErbB4 has been implicated in neuronal myelination, we investigated with diffusion tensor imaging (DTI) whether fractional anisotropy (FA)--a putative measure of neuronal myelination--is predicted by a risk haplotype of the ErbB4 gene. The effects of the ErbB4 genotype were investigated in healthy subjects (N=59; mean …

AdultMalePsychosisReceptor complexGenotypeNerve Fibers MyelinatedLateralization of brain functionTemporal lobeWhite matterMemoryRisk FactorsFractional anisotropyNeural PathwaysmedicineReaction TimeHumansAttentionPharmacologyEcho-Planar ImagingGenes erbBHuman brainmedicine.diseaseTemporal LobeFrontal LobePsychiatry and Mental healthmedicine.anatomical_structureDiffusion Magnetic Resonance ImagingHaplotypesSchizophreniaSchizophreniaAnisotropyFemalePsychologyNeuroscienceNeuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
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Solid bone tumors of the spine: Diagnostic performance of apparent diffusion coefficient measured using diffusion-weighted MRI using histology as a r…

2017

Purpose To assess the diagnostic performance of mean apparent diffusion coefficient (mADC) in differentiating benign from malignant bone spine tumors, using histology as a reference standard. Conventional magnetic resonance imaging (MRI) sequences have good reliability in evaluating spinal bone tumors, although some features of benign and malignant cancers may overlap, making the differential diagnosis challenging. Materials and Methods In all, 116 patients (62 males, 54 females; mean age 59.5 ± 14.1) with biopsy-proven spinal bone tumors were studied. Field strength/sequences: 1.5T MR system; T1-weighted turbo spin-echo (repetition time / echo time [TR/TE], 500/13 msec; number of excitatio…

AdultMalemedicine.medical_specialtyAdolescentIntraclass correlationGadoliniumchemistry.chemical_elementSensitivity and Specificity030218 nuclear medicine & medical imagingDiagnosis Differential03 medical and health sciencesYoung Adult0302 clinical medicineImage Interpretation Computer-AssistedmedicineEffective diffusion coefficientHumansRadiology Nuclear Medicine and imagingStage (cooking)AgedRetrospective StudiesAged 80 and overSpinal Neoplasmsmedicine.diagnostic_testReceiver operating characteristicbusiness.industryEcho-Planar ImagingReproducibility of ResultsMagnetic resonance imagingMiddle AgedReference StandardsConfidence intervalSpineDiffusion Magnetic Resonance Imagingchemistry030220 oncology & carcinogenesisFemaleRadiologyNuclear medicinebusinessDiffusion MRIJournal of magnetic resonance imaging : JMRI
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Linear chain surfactants at a planar interface: a comparative Monte Carlo study of several lattice models

1993

Linear chain surfactants in a densely packed arrangement (such as alkane chains in lipid monolayers in the “uniform tilt” structures) are described by a crude coarse-grained model where the endgroups grafted on the interface form a regular lattice and the chains are described by the bond fluctuation model with chains containing N = 4 effective monomers only. Square-well interactions between the monomers are studied for both the attractive and repulsive case for three choices of the interaction range. None of these models exhibits a structure with uniform tilt. For attractive interactions the last bond has a strong tendency to fold back thus leading to a very high density close to the interf…

Alkanechemistry.chemical_classificationQuantitative Biology::BiomoleculesStereochemistryMonte Carlo methodPolymerOligomerCondensed Matter::Soft Condensed Matterchemistry.chemical_compoundMonomerPlanarchemistryChemical physicsLattice (order)MonolayerDie Makromolekulare Chemie, Theory and Simulations
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Dynamic 2- and 3-connectivity on planar graphs

1992

We study the problem of maintaining the 2-edge-, 2-vertex-, and 3-edge-connected components of a dynamic planar graph subject to edge deletions. The 2-edge-connected components can be maintained in a total of O(n log n) time under any sequence of at most O(n) deletions. This gives O(log n) amortized time per deletion. The 2-vertex- and 3-edge-connected components can be maintained in a total of O(n log2n) time. This gives O(log2n) amortized time per deletion. The space required by all our data structures is O(n).

Amortized analysisBook embeddingPlanar straight-line graph1-planar graphPlanar graphCombinatoricssymbols.namesakePathwidthChordal graphTheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITYOuterplanar graphData_FILESsymbolsMathematicsofComputing_DISCRETEMATHEMATICSMathematics
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Melnikov functions and Bautin ideal

2001

The computation of the number of limit cycles which appear in an analytic unfolding of planar vector fields is related to the decomposition of the displacement function of this unfolding in an ideal of functions in the parameter space, called the Ideal of Bautin. On the other hand, the asymptotic of the displacement function, for 1-parameter unfoldings of hamiltonian vector fields is given by Melnikov functions which are defined as the coefficients of Taylor expansion in the parameter. It is interesting to compare these two notions and to study if the general estimations of the number of limit cycles in terms of the Bautin ideal could be reduced to the computations of Melnikov functions for…

Applied MathematicsComputationMathematical analysisPlanar vector fieldsParameter spacesymbols.namesakeDisplacement functionTaylor seriessymbolsDiscrete Mathematics and CombinatoricsVector fieldHamiltonian (quantum mechanics)Melnikov methodMathematicsQualitative Theory of Dynamical Systems
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Dimension estimates for the boundary of planar Sobolev extension domains

2020

We prove an asymptotically sharp dimension upper-bound for the boundary of bounded simply-connected planar Sobolev $W^{1,p}$-extension domains via the weak mean porosity of the boundary. The sharpness of our estimate is shown by examples.

Applied MathematicsMathematical analysisBoundary (topology)Extension (predicate logic)Physics::Classical PhysicsFunctional Analysis (math.FA)Sobolev spaceMathematics - Functional AnalysisPlanarDimension (vector space)46E35 28A75Mathematics - Classical Analysis and ODEsBounded functionClassical Analysis and ODEs (math.CA)FOS: MathematicsAnalysisMathematics
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Problems of coding stereo images in human memory

2010

This paper discusses the memorization and recall by man of a sequence of planar or stereoscopic images, including six frames that contain a planar strip (8×8 positions of the stimulus) or a volume strip (8×4×2 positions). At the recall stage, the subject chose between the stimulus and three distractors in each frame. It is shown that the times for recognition and recall are less for volume stimuli, while the percent of correct responses is greater for planar stimuli. For volume stimuli, the distribution of errors depends on the disparity between the target and the selected distractor. A model based on a heteroassociative neural network reproduces the error distribution for planar but not fo…

Artificial neural networkRecallComputer sciencebusiness.industryApplied MathematicsGeneral EngineeringHuman memoryStereoscopyStimulus (physiology)Atomic and Molecular Physics and OpticsMemorizationlaw.inventionComputational MathematicsPlanarlawComputer visionArtificial intelligencebusinessJournal of Optical Technology
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"Table 23" of "Energy dependence of event shapes and of alpha(s) at LEP-2."

1999

Distributions of Planarity at cm energies 133, 161 and 172 GeV.

Astrophysics::High Energy Astrophysical PhenomenaE+ E- --> HADRONSE+ E- --> JETSE+ E- ScatteringExclusiveHigh Energy Physics::ExperimentSingle Differential DistributionJet ProductionComputer Science::Computational GeometryNuclear ExperimentDN/DPLANARITY133.0-172.0
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"Table 24" of "Energy dependence of event shapes and of alpha(s) at LEP-2."

1999

Distribution of Planarity at cm energy 183 GeV.

Astrophysics::High Energy Astrophysical PhenomenaE+ E- --> HADRONSE+ E- --> JETSE+ E- ScatteringExclusiveHigh Energy Physics::ExperimentSingle Differential DistributionJet ProductionComputer Science::Computational GeometryNuclear ExperimentDN/DPLANARITY183.0
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2,2-Di­fluoro-3-(4-fluoro­phen­yl)-2H-benzo[e][1,3,2]oxaza­borinin-3-ium-2-uide

2017

There is one independent molecule in the asymmetric unit of the title compound, C13H9BF3NO, which crystallizes in the non-centrosymmetric space groupCc. In the molecular structure, the BF2-carrying ring is distorted from planarity and its mean plane makes a dihedral angle of 42.3 (1)° with the 4-fluorophenyl ring. F atoms are involved in all of the short intermolecular contacts of the crystal structure, which link molecules to form chains along [001] and [010].

BF2−salicylatescrystal structureChemistryCrystal structureDihedral angle010402 general chemistry010403 inorganic & nuclear chemistryRing (chemistry)01 natural sciencesPlanarity testing0104 chemical sciencesBF2 complexesCrystallographylcsh:QD901-999Moleculelcsh:CrystallographyUnit (ring theory)IUCrData / International Union of Crystallography
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