Results 81 to 90 of about 3,840,200 (275)
Positive solutions of elliptic nonpositone problems
Differential and Integral Equations, 1992 The authors give conditions for the existence or nonexistence of positive solutions of second order subcritical elliptic nonpositone problems. No assumption is made that the problems be radial nor that they possess a variational structure.
W. Allegretto +2 more
openaire +5 more sources
Molecular bases of circadian magnesium rhythms across eukaryotes
FEBS Letters, EarlyView.Circadian rhythms in intracellular [Mg2+] exist across eukaryotic kingdoms. Central roles for Mg2+ in metabolism suggest that Mg2+ rhythms could regulate daily cellular energy and metabolism. In this Perspective paper, we propose that ancestral prokaryotic transport proteins could be responsible for mediating Mg2+ rhythms and posit a feedback model ...
Helen K. Feord, Gerben van Ooijen
wiley +1 more source
Positive solutions for the one-dimensional Sturm-Liouville superlinear p-Laplacian problem
Electronic Journal of Differential Equations, 2018 We prove the existence of positive classical solutions for the p-Laplacian problem $$\displaylines{ -(r(t)\phi (u'))'=f(t,u),\quad t\in (0,1), \cr au(0)-b\phi ^{-1}(r(0))u'(0)=0,\ cu(1)+d\phi ^{-1}(r(1))u'(1)=0, }$$ where $\phi (s)=|s|^{p-2}s$, $p ...
Khanh Duc Chu, Dang Dinh Hai
doaj
Positive Solutions of nth-Order Boundary Value Problems with Integral Boundary Conditions
Mathematical Modelling and Analysis, 2015 In this paper, by using double fixed point theorem and a new fixed point theorem, some sufficient conditions for the existence of at least two and at least three positive solutions of an nth-order boundary value problem with integral boundary conditions ...
Ilkay Yaslan Karaca, Fatma Tokmak Fen
doaj +1 more source
Disordered but rhythmic—the role of intrinsic protein disorder in eukaryotic circadian timing
FEBS Letters, EarlyView.Unstructured domains known as intrinsically disordered regions (IDRs) are present in nearly every part of the eukaryotic core circadian oscillator. IDRs enable many diverse inter‐ and intramolecular interactions that support clock function. IDR conformations are highly tunable by post‐translational modifications and environmental conditions, which ...
Emery T. Usher, Jacqueline F. Pelham
wiley +1 more source
Function‐driven design of a surrogate interleukin‐2 receptor ligand
FEBS Letters, EarlyView.Interleukin (IL)‐2 signaling can be achieved and precisely fine‐tuned through the affinity, distance, and orientation of the heterodimeric receptors with their ligands. We designed a biased IL‐2 surrogate ligand that selectively promotes effector T and natural killer cell activation and differentiation. Interleukin (IL) receptors play a pivotal role in
Ziwei Tang +9 more
wiley +1 more source
Nonexistence of radial positive solutions for a nonpositone problem
Electronic Journal of Differential Equations, 2011 In this article we study the nonexistence of radial positive solutions for a nonpositone problem when the nonliearity is superlinear and has more than one zero.
Said Hakimi, Abderrahim Zertiti
doaj
Time after time – circadian clocks through the lens of oscillator theory
FEBS Letters, EarlyView.Oscillator theory bridges physics and circadian biology. Damped oscillators require external drivers, while limit cycles emerge from delayed feedback and nonlinearities. Coupling enables tissue‐level coherence, and entrainment aligns internal clocks with environmental cues.
Marta del Olmo +2 more
wiley +1 more source
Two positive solutions for second-order functional and ordinary boundary-value problems
Electronic Journal of Differential Equations, 2005 In this paper we use a fixed point theorem due to Avery and Henderson to prove, under appropriate conditions, the existence of at least two positive solutions for a second-order functional and ordinary boundary-value problem.
Kyriakos G. Mavridis +1 more
doaj
On Optimal Hardy Inequalities in Cones
Bruno Pini Mathematical Analysis Seminar, 2014 For a given subcritical Schrödinger operator in a cone in ℝn with a given Hardy potential corresponding to the distance to the boundary of the cone, we present an explicit optimal Hardy-type improvement.
Baptiste Devyver +2 more
doaj +1 more source