Search results for "BIF"
showing 10 items of 539 documents
On the number of solutions of a Duffing equation
1991
The exact number of solutions of a Duffing equation with small forcing term and homogeneous Neumann boundary conditions is given. Several bifurcation diagrams are shown.
Transdiagnostic dimensions of psychopathology at first episode psychosis: findings from the multinational EU-GEI study.
2019
Background\ud The value of the nosological distinction between non-affective and affective psychosis has frequently been challenged. We aimed to investigate the transdiagnostic dimensional structure and associated characteristics of psychopathology at First Episode Psychosis (FEP). Regardless of diagnostic categories, we expected that positive symptoms occurred more frequently in ethnic minority groups and in more densely populated environments, and that negative symptoms were associated with indices of neurodevelopmental impairment.\ud \ud Method\ud This study included 2182 FEP individuals recruited across six countries, as part of the EUropean network of national schizophrenia networks st…
Intermittent-Type Chaos in Nonsinusoidal Driven Oscillators
2000
The intermittent-type chaos occurring in rf- and dc- nonsinusoidal driven oscillators is investigated analytically and numerically. The attention is focused on a general class of oscillators in which the total potential VRP(,r) is the Remoissenet-Peyrard potential which has constant amplitude and is 2π-periodic in , and whose shape can be varied as a function of parameter r ( |r| < 1). A simple physical model for calculating analytically the Melnikov function is proposed. The onset of chaos is studied through an analysis of the phase space, a construction of the bifurcation diagram and a computation of the Lyapunov exponent. The parameter regions of chaotic behaviour predicted by the theore…
Abelian integrals and limit cycles
2006
Abstract The paper deals with generic perturbations from a Hamiltonian planar vector field and more precisely with the number and bifurcation pattern of the limit cycles. In this paper we show that near a 2-saddle cycle, the number of limit cycles produced in unfoldings with one unbroken connection, can exceed the number of zeros of the related Abelian integral, even if the latter represents a stable elementary catastrophe. We however also show that in general, finite codimension of the Abelian integral leads to a finite upper bound on the local cyclicity. In the treatment, we introduce the notion of simple asymptotic scale deformation.
Sociālajos tīklos anketēto iedzīvotāju informētība par probiotiku lietošanas ieguvumiem veselības uzlabošanā un uzturēšanā
2016
Maģistra darba mērķis bija apkopot teorētisko informāciju par probiotiku lietošanas ieguvumiem veselības uzlabošanā un uzturēšanā un apzināt sociālo tīklu lietotāju informētību par šiem ieguvumiem, izvērtējot arī respondentu izglītību (saistīta vai nesaistīta ar veselības aprūpi). Pētījums tika veikts ar aptaujas anketu palīdzību, tās izplatot elektroniskajā vidē. Tika saņemtas 200 derīgas anketas, kas tika izmantotas iegūtās informācijas izvērtēšanai. Apkopojot rezultātus tika secināts, ka probiotikas ir populārs produkts un to izvēlas lietot kā papildterapijas līdzekli visbiežāk pēc ārsta rekomendācijām. Cilvēki probiotikas visbiežāk saista ar caureju un liela daļa tās lieto pēc antibioti…
Estrategias biotecnológicas para reducir el contenido en fitatos en productos fermentados de origen vegetal mediante fitasas de bifidobacterias
2015
Los alimentos integrales de origen vegetal, concretamente, los cereales de grano entero y leguminosas se caracterizan por ser una fuente excelente de fibra dietética y poseer un elevado contenido en compuestos fitoquímicos. Además de proporcionar macronutrientes, como carbohidratos complejos y proteínas, también destacan por su contenido en micronutrientes como son las vitaminas y minerales. Sin embargo, su ingesta conlleva a la vez un aporte en sustancias antinutritivas, como los fitatos, con gran afinidad por minerales, proteínas y elementos traza, que pueden comprometer su absorción por formación de quelatos estables en el tracto digestivo. Una hidrólisis o defosforilación parcial de los…
CENTRAL LIMIT THEOREM FOR KERNEL ESTIMATOR OF INVARIANT DENSITY IN BIFURCATING MARKOV CHAINS MODELS
2021
Bifurcating Markov chains (BMC) are Markov chains indexed by a full binary tree representing the evolution of a trait along a population where each individual has two children. Motivated by the functional estimation of the density of the invariant probability measure which appears as the asymptotic distribution of the trait, we prove the consistence and the Gaussian fluctuations for a kernel estimator of this density based on late generations. In this setting, it is interesting to note that the distinction of the three regimes on the ergodic rate identified in a previous work (for fluctuations of average over large generations) disappears. This result is a first step to go beyond the thresh…
Pattern formation and bifurcation analysis for some chemotaxis-reaction-diffusion systems
Geometric and morphologic evolution of normal fault planes and traces from 2D to 4D data
2003
Abstract The detailed 3D geometry of normal fault planes is described and analysed using datasets from outcrop studies (2D), seismic surveys (3D) and analogue models (4D). Different geometric configurations of simple isolated normal faults are studied by reference to processes of normal fault propagation. When a normal fault propagates without interacting with other fault zones, the entire border of the principal plane displays characteristic connected secondary structures. These secondary structures cause bifurcations of the principal fault terminations. The along-strike terminations of the principal plane display typical bifurcation configurations (‘ear geometry‘). The orientation of the …
A Functionalized Noncovalent Macrocyclic Multiporphyrin Assembly from a Dizinc(II) Bis-Porphyrin Receptor and a Free-Base Dipyridylporphyrin
2003
The bis-porphyrin system ZnP 2 , in which two zinc porphyrins are connected by a phenanthroline linker in an oblique fashion, acts as a bifunctional receptor towards the complexation of free-base meso-5,10-bis(4'-pyridyl)-15,20-diphenylporphyrin (4'-cisDPyP). In solution, NMR spectroscopy evidenced quantitative formation of the tris-porphyrin macrocyclic assembly ZnP 2 (4'-cisDPyP), in which the two fragments are held together by two axial 4'-N(pyridyl)-Zn interactions. The remarkable stability of the edifice (an association constant of about 6 x 10 8 M - 1 was determined by UV/Vis absorption and emission titration experiments in toluene) is due to the almost perfect geometrical match betwe…