Search results for " Genetics"

showing 10 items of 4169 documents

The coalescent in population models with time-inhomogeneous environment

2002

AbstractThe coalescent theory, well developed for the class of exchangeable population models with time-homogeneous reproduction law, is extended to a class of population models with time-inhomogeneous environment, where the population size is allowed to vary deterministically with time and where the distribution of the family sizes is allowed to change from generation to generation. A new class of time-inhomogeneous coalescent limit processes with simultaneous multiple mergers arises. Its distribution can be characterized in terms of product integrals.

Statistics and ProbabilityWeak convergencePopulation geneticsApplied MathematicsPopulation sizeVarying environmentPopulation geneticsProduct integralHeavy traffic approximationProduct integralStirling numbersCoalescent theoryFamily SizesDiffusion approximationPopulation modelAncestorsModelling and SimulationModeling and SimulationEconometricsQuantitative Biology::Populations and EvolutionCoalescentStatistical physicsWeak convergenceMathematicsStochastic Processes and their Applications
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Main individual and product characteristics influencing in-mouth flavour release during eating masticated food products with different textures: mech…

2013

Research Areas: Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; A mechanistic model predicting flavour release during oral processing of masticated foods was developed. The description of main physiological steps (product mastication and swallowing) and physical mechanisms (mass transfer, product breakdown and dissolution) occurring while eating allowed satisfactory simulation of in vivo release profiles of ethyl propanoate and 2-nonanone, measured by Atmospheric Pressure Chemical Ionization Mass Spectrometry on ten representative subjects during the consumption of four cheeses with different textures. Model sensitivity analysis showed that the main paramet…

Statistics and Probability[ INFO.INFO-MO ] Computer Science [cs]/Modeling and SimulationPhysiology[ SDV.AEN ] Life Sciences [q-bio]/Food and NutritionFlavourAroma compoundMass spectrometryModels BiologicalDynamic modelMass SpectrometryGeneral Biochemistry Genetics and Molecular BiologyEatingchemistry.chemical_compound[SPI]Engineering Sciences [physics]CheeseMass transfer[ SPI ] Engineering Sciences [physics]HumansAroma compoundMass transferFood scienceParticle SizeSalivaMasticationAromaFood oral processing2. Zero hungerMass transfer coefficientMouthGeneral Immunology and MicrobiologybiologyAirApplied MathematicsSaliva ArtificialGeneral MedicineKetonesbiology.organism_classification[INFO.INFO-MO]Computer Science [cs]/Modeling and SimulationDeglutitionchemistryFoodTasteModeling and SimulationMasticationDigestionPropionatesBolus (digestion)General Agricultural and Biological Sciences[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition
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Dynamics of Pattern Formation in Biomimetic Systems

2008

This paper is an attempt to conceptualize pattern formation in self-organizing systems and, in particular, to understand how structures, oscillations or waves arise in a steady and homogenous environment, a phenomenon called symmetry breaking. The route followed to develop these ideas was to couple chemical oscillations produced by Belousov-Zhabotinsky reaction with confined reaction environments, the latter being an essential requirement for any process of Life. Special focus was placed on systems showing organic or lipidic compartments, which represent more reliable biomimetic matrices.

Statistics and Probability{CHEMICAL} {OSCILLATORS}Belousov-Zhabotinsky reactionLipid BilayersPattern formationNanotechnology{CHEMICAL} {OSCILLATORS}; Lipid systems; Reverse microemulsionsModels BiologicalTuring structuresGeneral Biochemistry Genetics and Molecular BiologyDiffusionBiomimeticsChemical oscillatorsAnimalsSymmetry breakingPhysicsGeneral Immunology and MicrobiologyChemistry PhysicalSystems BiologyApplied MathematicsLipid systemsBiomimetic systemsGeneral MedicineBelousov-Zhabotinsky reaction; Chemical oscillators; Turing structures; Biomimetic systems; Lipid systems; Reverse microemulsionsReverse microemulsionsBelousov–Zhabotinsky reactionModeling and SimulationEmulsionsGeneral Agricultural and Biological SciencesBiological system
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Bioactive pyrrole alkaloids isolated from the Red Sea : marine sponge Stylissa carteri

2017

Abstract Fifteen pyrrole alkaloids were isolated from the Red Sea marine sponge Stylissa carteri and investigated for their biological activities. Four of them were dibrominated [(+) dibromophakelline, Z-3-bromohymenialdisine, (±) ageliferin and 3,4-dibromo-1H-pyrrole-2-carbamide], nine compounds were monobrominated [(−) clathramide C, agelongine, (+) manzacidin A, (−) 3-bromomanzacidin D, Z-spongiacidin D, Z-hymenialdisine, 2-debromostevensine, 2-bromoaldisine and 4-bromo-1H-pyrrole-2-carbamide)] and finally, two compounds were non-brominated derivatives viz., E-debromohymenialdisine and aldisine. The structure elucidations of isolated compounds were based on 1D & 2D NMR spectroscopic …

StereochemistryCell Survival01 natural sciencesGeneral Biochemistry Genetics and Molecular BiologyCell LineRSchemistry.chemical_compoundAlkaloidsAnimalsHumansPyrrolesProtein kinase ACytotoxicityIndian OceanAgeliferinPyrrolebiologyMolecular Structure010405 organic chemistryKinasebiology.organism_classificationHCT116 Cells0104 chemical sciencesPorifera010404 medicinal & biomolecular chemistrySpongechemistryStylissa carteriDrug Screening Assays AntitumorTwo-dimensional nuclear magnetic resonance spectroscopy
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2-Methyl-1-phenylsulfanyl-1,2-dicarba-closo-dodecaborane(12)

2002

In the title o-carborane derivative, C(9)H(18)B(10)S, the methyl and phenylsulfanyl groups are connected to the C atoms of the carborane cage. The C(cage)-C(cage) distance is 1.708 (4) A.

StereochemistryGeneral MedicineCrystal structure010402 general chemistry010403 inorganic & nuclear chemistry01 natural sciencesMedicinal chemistryGeneral Biochemistry Genetics and Molecular Biology3. Good health0104 chemical scienceschemistry.chemical_compoundchemistryCarboraneDerivative (chemistry)Acta Crystallographica Section C Crystal Structure Communications
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3-formylphenylboronic acid.

2004

The molecule of the title compound, C(7)H(7)BO(3), is planar, and the bond lengths and angles are typical. The formyl group is essentially coplanar with the benzene ring but does not influence significantly the distortion of the ring, although the formyl group does have a strong influence on the crystal packing. The geometry of the boronic acid group is typical. In the crystal structure, the molecules are linked by O-H...O hydrogen bonds.

StereochemistryHydrogen bondGeneral MedicineCrystal structureRing (chemistry)General Biochemistry Genetics and Molecular BiologyCrystalBond lengthCrystallographychemistry.chemical_compoundchemistryGroup (periodic table)BenzeneBoronic acidActa crystallographica. Section C, Crystal structure communications
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Two (E)-2-({[4-(dialkylamino)phenyl]imino}methyl)-4-nitrophenols.

2012

The slow evaporation of analytical NMR samples resulted in the formation of crystals of (E)-2-({[4-(dimethylamino)phenyl]imino}methyl)-4-nitrophenol, C15H15N3O3, (I), and (E)-2-({[4-(diethylamino)phenyl]imino}methyl)-4-nitrophenol, C17H19N3O3, (II). Despite the small structural difference between these twoN-salicylideneaniline derivatives, they show different space groups and diverse molecular packing. The molecules of both compounds are close to being planar due to an intramolecular O—H...N hydrogen bond. The 4-alkylamino-substituted benzene ring is inclined at an angle of 13.44 (19)° in (I) and 2.57 (8)° in (II) with respect to the 4-nitro-substituted phenol ring. Only very weak intermole…

StereochemistryHydrogen bondStackingSpace groupGeneral MedicineCrystal structureStructural differenceRing (chemistry)General Biochemistry Genetics and Molecular BiologyCrystallographychemistry.chemical_compoundchemistryPhenolBenzeneta116Acta crystallographica. Section C, Crystal structure communications
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Eukaryotic tRNAs(Pro): primary structure of the anticodon loop; presence of 5-carbamoylmethyluridine or inosine as the first nucleoside of the antico…

1990

The modified nucleoside U*, located in the first position of the anticodon of yeast, chicken liver and bovine liver tRNA(Pro) (anticodon U*GG), has been determined by means of TLC, HPLC, ultraviolet spectrum and gas chromatography-mass spectrometry. The structure was established as 5-carbamoylmethyluridine (ncm5U). In addition, we report on the primary structures of the above-mentioned tRNAs as well as those which have the IGG anticodon. In yeast, the two tRNA(Pro) (anticodons U*GG and IGG) differ by eight nucleotides, whereas in chicken and in bovine liver, both anticodons are carried by the same 'body tRNA' with one posttranscriptional exception at position 32, where pseudouridine is asso…

StereochemistryMolecular Sequence DataBiophysicsBiologyBiochemistryPseudouridinechemistry.chemical_compoundRNA Transfer ProRNA TransferStructural BiologyYeastsGeneticsmedicineAnticodonAnimalsNucleotideInosineUridinechemistry.chemical_classificationChromatographyBase SequenceMolecular StructureProtein primary structureFungal geneticsRNARNA FungalRNA Transfer Amino Acid-SpecificInosinechemistryBiochemistryTransfer RNANucleic Acid ConformationCattleSpectrophotometry UltravioletNucleosideChickensmedicine.drugBiochimica et biophysica acta
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Polymorphism in Cs[AgZn(NCS)4].

2002

The title compound, caesium silver zinc tetrathiocyanate, crystallizes in two polymorphic forms, in space groups P2(1)/n and C2/c. Both structures form a continuous three-dimensional network. The structure in C2/c contains a delocalized Ag atom in a binuclear-like anion, where two [Ag(NCS)(4)] units (delocalized Ag as an average) share two common NCS(-) ligands.

StereochemistrySpace groupchemistry.chemical_elementGeneral MedicineCrystal structureZincMolecular biologyGeneral Biochemistry Genetics and Molecular BiologyIonCrystallographyDelocalized electronchemistryPolymorphism (materials science)CaesiumMoleculeActa crystallographica. Section C, Crystal structure communications
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Tetrakis(1-ethyl-1H-1,2,4-triazole-κN4)bis(nitrato-κO)copper(II) and bis(nitrato-κO)tetrakis(1-propyl-1H-1,2,4-triazole-κN4)copper(II)

2005

The copper(II) environments for tetrakis(1-ethyl-1,2,4-triazole)dinitratocopper(II), [Cu(NO 3 ) 2 (C 4 H 7 N 3 ) 4 ], and tetrakis-(1-propyl-1,2,4-triazole)dinitratocopper(II), [Cu(NO 3 ) 2 (C 5 -H 9 N 3 ) 4 ], are distorted square bipyramidal. Both structures are centrosymmetric, with the copper(II) ions located at inversion centers coordinated by four N atoms of four triazole molecules and by two O atoms of two nitrate ions in an elongated octahedral geometry. This elongation is a result of the Jahn-Teller effect. The largest distortion is that of the N-Cu-O angles, which differ from 90 by 5.68 (10)° in the ethyl and 5.59 (8)° in the propyl derivative.

StereochemistryTriazolechemistry.chemical_element124-TriazoleGeneral MedicineCrystal structureCopperMedicinal chemistryGeneral Biochemistry Genetics and Molecular BiologyBipyramidchemistry.chemical_compoundchemistryTransition metalOctahedral molecular geometryMoleculeActa Crystallographica Section C Crystal Structure Communications
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