Search results for "UNIQUE"
showing 10 items of 268 documents
Existence and uniqueness results for a nonlinear evolution equation arising in growing cell populations
2014
Abstract The present paper is concerned with a nonlinear initial–boundary value problem derived from a model introduced by Rotenberg (1983) describing the growth of a cell population. Each cell of this population is distinguished by two parameters: its degree of maturity μ and its maturation velocity v . At mitosis, the daughter cells and mother cells are related by a general reproduction rule. We prove existence and uniqueness results in the case where the total cross-section and the boundary conditions are depending on the total density of population. Local and nonlocal reproduction rules are discussed.
An existence and uniqueness principle for a nonlinear version of the Lebowitz-Rubinow model with infinite maximum cycle length
2017
The present article deals with existence and uniqueness results for a nonlinear evolution initial-boundary value problem, which originates in an age-structured cell population model introduced by Lebowitz and Rubinow (1974) describing the growth of a cell population. Cells of this population are distinguished by age a and cycle length l. In our framework, daughter and mother cells are related by a general reproduction rule that covers all known biological ones. In this paper, the cycle length l is allowed to be infinite. This hypothesis introduces some mathematical difficulties. We consider both local and nonlocal boundary conditions.
K-kertaisesti kiellettyjen uniikkien β-siirtymien faasiavaruusintegraalit
2018
Tässä tutkimuksessa perehdytään K-kertaisesti kiellettyjen uniikkien beetasiirtymien faasiavaruusintegraaleihin. K-kertaisesti kielletyt uniikit beetasiirtymät ovat beetahajoamisten alaryhmä, ja faasiavaruusintegraalit kuvaavat hajoamisreaktion jälkeisiä lopputiloja ja antavat muun muassa tärkeää tietoa siirtymän hajoamisvakiosta. Tutkimuksessa laskettiin numeerisesti faasiavaruusintegraalit useille tunnetuille beetasiirtymille, jotka voivat olla kaksi- tai useampikertaisesti kiellettyjä. Saatua laskentadataa analysoitiin eri näkökulmista. Tärkein näkökulma on kielletyn uniikin beetasiirtymän ja samaa beetahajoamista kuvaavan perus- eli sallitun siirtymän välinen suhde, koska tämä näkökulma…
On the Landis conjecture for the fractional Schrödinger equation
2023
In this paper, we study a Landis-type conjecture for the general fractional Schrödinger equation ((−P)s+q)u=0. As a byproduct, we also prove the additivity and boundedness of the linear operator (−P)s for non-smooth coefficents. For differentiable potentials q, if a solution decays at a rate exp (−∣x∣1+), then the solution vanishes identically. For non-differentiable potentials q, if a solution decays at a rate exp (−∣x∣4s−14s+), then the solution must again be trivial. The proof relies on delicate Carleman estimates. This study is an extension of the work by Rüland and Wang (2019). peerReviewed
Predicting the potential global range of common ragweed (Ambrosia artemisiifolia) using biologically informed and correlative species distribution mo…
2012
National audience
Using 2-colorings in the theory of uniquely Hamiltonian graphs
2019
We use the concept of 2-coloring in analyzing UH3 graphs and building exact specifications of functions to find new UH3 graphs by Hamiltonian cycle edge extractions
Il Dialogo Possibile tra Educazione e Neuroscienze. Un'indagine sulle Prassi Neuroeducative degli Insegnanti
2022
L’orizzonte neuroscientifico corrobora le Scienze dell’Educazione compor-tando un reale ripensamento dei processi di insegnamento e apprendimento in favore di percorsi educativi di qualità. Sondando il carattere dialogico della Neuroeducazione si riportano alcune evidenze neuroscientifiche che affermano l’unicità di ogni cervello; si analizzano le ricadute neuropedagogiche per poi volgere lo sguardo ad un’indagine svolta con un gruppo di 1428 insegnanti della regione Sicilia per analizzare le loro prassi educativo-didattiche fondate nell’orizzonte neuroeducativo. Il processo di analisi ha evidenziato alcuni dati significativi che lasciano intendere una necessaria opera di formazione in fa-v…
Boundary value problem with integral condition for a Blasius type equation
2016
The steady motion in the boundary layer along a thin flat plate, which is immersed at zero incidence in a uniform stream with constant velocity, can be described in terms of the solution of the differential equation x'''= -xx'', which satisfies the boundary conditions x(0) = x'(0) = 0, x'(∞) = 1. The author investigates the generalized boundary value problem consisting of the nonlinear third-order differential equation x''' = -trx|x|q-1x'' subject to the integral boundary conditions x(0) = x'(0) = 0, x'(∞) = λ∫0ξx(s) ds, where 0 0 is a parameter. Results on the existence and uniqueness of solutions to boundary value problem are established. An illustrative example is provided.
Analysis of a viscoelastic phase separation model
2020
A new model for viscoelastic phase separation is proposed, based on a systematically derived conservative two-fluid model. Dissipative effects are included by phenomenological viscoelastic terms. By construction, the model is consistent with the second law of thermodynamics, and we study well-posedness of the model, i.e., existence of weak solutions, a weak-strong uniqueness principle, and stability with respect to perturbations, which are proven by means of relative energy estimates. A good qualitative agreement with mesoscopic simulations is observed in numerical tests.
Never say never again: A bone graft infection due to a hornet sting, thirty-nine years after cranioplasty
2017
Background: Cranioplasty (CP) is a widespread surgical procedure aimed to restore skull integrity and physiological cerebral hemodynamics, to improve neurological functions and to protect the underlying brain after a life-saving decompressive craniectomy (DC). Nevertheless, CP is still burdened by surgical complications, among which early or late graft infections are the most common outcome-threatening ones. Case Description: We report the case of 48-year-old man admitted to our neurosurgical unit because of a painful right frontal swelling and 1-week purulent discharge from a cutaneous fistula. He had been undergone frontal CP because of severe traumatic brain injury (TBI) when he was 9-ye…