Search results for " Geometry."

showing 10 items of 2189 documents

On the growth and form of cortical convolutions

2016

International audience; The rapid growth of the human cortex during development is accompanied by the folding of the brain into a highly convoluted structure1-3. Recent studies have focused on the genetic and cellular regulation of cortical growth4-8, but understanding the formation of the gyral and sulcal convolutions also requires consideration of the geometry and physical shaping of the growing brain9-15. To study this, we use magnetic resonance images to build a 3D-printed layered gel mimic of the developing smooth fetal brain; when immersed in a solvent, the outer layer swells relative to the core, mimicking cortical growth. This relative growth puts the outer layer into mechanical com…

0301 basic medicinePhysicsNonlinear phenomenata114growthGeneral Physics and Astronomygyrificationta3112SwellFetal brain03 medical and health sciences030104 developmental biology0302 clinical medicinemedicine.anatomical_structureCerebral cortexbrain geometrymedicineBiophysicscerebral cortexComputational biophysics[PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph][SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing030217 neurology & neurosurgery
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The latent geometry of the human protein interaction network

2017

Abstract Motivation A series of recently introduced algorithms and models advocates for the existence of a hyperbolic geometry underlying the network representation of complex systems. Since the human protein interaction network (hPIN) has a complex architecture, we hypothesized that uncovering its latent geometry could ease challenging problems in systems biology, translating them into measuring distances between proteins. Results We embedded the hPIN to hyperbolic space and found that the inferred coordinates of nodes capture biologically relevant features, like protein age, function and cellular localization. This means that the representation of the hPIN in the two-dimensional hyperboli…

0301 basic medicineStatistics and ProbabilityGeometric analysisComputer scienceHyperbolic geometrySystems biologyComplex systemContext (language use)GeometryBiochemistryProtein–protein interaction03 medical and health sciencesInteraction networkHumansProtein Interaction MapsRepresentation (mathematics)Cluster analysisMolecular BiologySystems BiologyHyperbolic spaceProteinsFunction (mathematics)Original PapersComputer Science ApplicationsComputational Mathematics030104 developmental biologyComputational Theory and MathematicsEmbeddingSignal transductionAlgorithmsSignal Transduction
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Curve Extraction by Geodesics Fusion: Application to Polymer Reptation Analysis

2016

© Springer International Publishing Switzerland 2016. In the molecular field, researchers analyze dynamics of polymers by microscopy: several measurements such as length and curvature are performed in their studies. To achieve correct analysis they need to extract the curve representing as good as possible the observed polymer shape which is a grayscale thick curve with noise and blur. We propose, in this paper, a method to extract such a curve. A polymer chain moves in a snake-like fashion (Reptation): it can self-intersect and form several complex geometries. To efficiently extract the different geometries, we generate the curve by computing a piecewise centerline browsing the shape by ge…

0301 basic medicine[ INFO ] Computer Science [cs]GeodesicGeometry02 engineering and technologyCurvature03 medical and health sciencesGraph traversalMolecular image analysis[INFO]Computer Science [cs]Grayscale curvesMorphological operationsdistanceMathematicsMicroscopyCurve orientationMathematical analysis021001 nanoscience & nanotechnologyReptation030104 developmental biologyGeodesics fusionPiecewiseShape extractionCurve sketching0210 nano-technologyShape analysis (digital geometry)
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Using Genetic Algorithms for Optimizing the PPC in the Highway Horizontal Alignment Design.

2016

Various studies have emphasized the interesting advantages related to the use of new transition curves for improving the geometric design of highway horizontal alignments. In a previous paper, one of the writers proposed a polynomial curve, called a polynomial parametric curve (PPC), proving its efficiency in solving several design problems characterized by a very complex geometry (egg-shaped transition, transition between reversing circular curves, semidirect and inner-loop connections, and so on). The PPC also showed considerable advantages from a dynamic perspective, as evidenced by the analysis of the main dynamic variables related to motion (as well as rate of change of radial accelera…

050210 logistics & transportationPolynomialMathematical optimizationFitness function05 social sciencesPerspective (graphical)Motion (geometry)020101 civil engineering02 engineering and technologyTransition curve0201 civil engineeringComputer Science ApplicationsGeometric designComplex geometryGenetic algorithmGenetic algorithms Horizontal alignment Polynomial curve Transition curve0502 economics and businessHorizontal alignment.Polynomial curveSettore ICAR/04 - Strade Ferrovie Ed AeroportiReversingParametric equationAlgorithmCivil and Structural EngineeringMathematics
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The relationship between loading history and proximal femoral diaphysis cross-sectional geometry

2017

Objectives We investigated the relationship between loading history and bone biomechanical properties used in physical activity reconstructions. These bone properties included bone bending and torsional strength (J), cortical area (CA), the direction of the major axis (theta angle), and element shape ratios determined from cross sections of standardized bone length. In addition, we explored the applicability of anatomically determined cross sections. Methods Our material consisted of hip and proximal thigh magnetic resonance images of Finnish female athletes (N = 91) engaged in high-jump, triple-jump, endurance running, swimming, power-lifting, soccer and squash; along with a group of activ…

060101 anthropologyBone densityPhysical activityCross sectional geometry030209 endocrinology & metabolism06 humanities and the artsAnatomyThighSkeleton (computer programming)Bone length03 medical and health sciences0302 clinical medicinemedicine.anatomical_structureFemoral diaphysisAnthropologyGeneticsmedicine0601 history and archaeologyAnatomySkeletal materialhuman activitiesEcology Evolution Behavior and SystematicsMathematicsAmerican Journal of Human Biology
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Magic informationally complete POVMs with permutations

2017

Eigenstates of permutation gates are either stabilizer states (for gates in the Pauli group) or magic states, thus allowing universal quantum computation [M. Planat and Rukhsan-Ul-Haq, Preprint 1701.06443]. We show in this paper that a subset of such magic states, when acting on the generalized Pauli group, define (asymmetric) informationally complete POVMs. Such IC-POVMs, investigated in dimensions $2$ to $12$, exhibit simple finite geometries in their projector products and, for dimensions $4$ and $8$ and $9$, relate to two-qubit, three-qubit and two-qutrit contextuality.

1003permutation groups159informationally complete povmsFOS: Physical sciences01 natural sciences157[SPI.MAT]Engineering Sciences [physics]/Materialslaw.inventionCombinatorics81P50 81P68 81P13 81P45 20B05Permutationlaw0103 physical sciences1009[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics010306 general physicslcsh:ScienceEigenvalues and eigenvectorsQuantum computer[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph]PhysicsQuantum Physics120Multidisciplinary010308 nuclear & particles physicsPhysicsMagic (programming)Q Science (General)16. Peace & justiceKochen–Specker theoremProjectorfinite geometryPauli groupquantum contextualitylcsh:QPreprintmagic statesQuantum Physics (quant-ph)Research Article
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Crystal and solution structures of di-n-butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: E…

2009

Abstract Reactions of nBu2SnCl(L1) (1), where L1 = acid residue of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol, with various substituted benzoic acids in refluxing toluene, in the presence of triethylamine, yielded dimeric mixed ligand di-n-butyltin(IV) complexes of composition [nBu2Sn(L1)(L2–6)]2 where L2 = benzene carboxylate (2), L3 = 2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoate (3), L4 = 5-[(E)-2-(4-methylphenyl)-1-diazenyl]-2-hydroxybenzoate (4), L5 = 2-{(E)-4-hydroxy-3-[(E)-4-chlorophenyliminomethyl]-phenyldiazenyl}benzoate (5) and L6 = 2-[(E)-(3-formyl-4-hydroxyphenyl)-diazenyl]benzoate (6). All complexes (1–6) have been characterized by elemental analyses, IR, 1H,…

10120 Department of Chemistry[(E)81303 Biochemistry5DenticityStereochemistry12Crystal structuredinBiochemistrybutyltin(IV) complexes(4Inorganic Chemistrychemistry.chemical_compoundPentagonal bipyramidal molecular geometry540 ChemistryMaterials ChemistryCarboxylatePhysical and Theoretical Chemistry2505 Materials ChemistryCoordination geometryXmixed ligandsol1604 Inorganic ChemistryChemistryCrystal structurebenzoic acidOrganic Chemistry5-[(E)-2-(4-methoxyphenyl)-1- diazenyl]quinolin-8-ol Di-n-butyltin(IV) complexes Benzoic acid Mixed ligands Solution and solid-state tin NMR Crystal structureNuclear magnetic resonance spectroscopysolution and solid state tinNMRBond lengthTrigonal bipyramidal molecular geometryCrystallographydiazenyl]quinolinmethoxyphenyl)Settore CHIM/03 - Chimica Generale E Inorganica1606 Physical and Theoretical Chemistry1605 Organic Chemistry
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"Table 49" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"

2020

$\phi$/K$_{\mathrm{S}}^{0}$ yield ratio vs transverse momentum - V0M multiplicity class II

13000.0Proton-Proton CollisionsP P --> Phi+X and P P --> K0S+XComputer Science::Computational GeometrySIGyieldPhiResonanceV0M Multiplicity
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"Table 52" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"

2020

$\phi$/K$_{\mathrm{S}}^{0}$ double yield ratio vs transverse momentum - V0M multiplicity class II / V0M multiplicity class X

13000.0Proton-Proton CollisionsP P --> phi+X and P P --> K0S+XComputer Science::Computational GeometrySIGyieldPhiResonanceV0M Multiplicity
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"Table 54" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"

2020

Significance of $\phi$/K$_{\mathrm{S}}^{0}$ double yield ratio vs transverse momentum - V0M multiplicity class II / V0M multiplicity class X

13000.0Proton-Proton CollisionsP P --> phi+X and P P --> K0S+XComputer Science::Computational GeometrySIGyieldPhiResonanceV0M Multiplicity
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