Exploring heart rate variability as a biomarker for frailty: A narrative review
European Journal of Clinical Investigation, Volume 56, Issue 4, April 2026.Frailty arises from progressive multisystem dysregulation, prompting interest in biomarkers that capture declining physiological reserve. This review positions heart rate variability (HRV) within this evolving biomarker landscape, outlining its physiological basis, analytical domains and relevance to clinical research.
Luca Tagliafico +5 more
wiley +1 more source
A Miyaoka–Yau inequality for hyperplane arrangements in CPn$\mathbb {CP}^n$
Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.Abstract Let H$\mathcal {H}$ be a hyperplane arrangement in CPn$\mathbb {CP}^n$. We define a quadratic form Q$Q$ on RH$\mathbb {R}^{\mathcal {H}}$ that is entirely determined by the intersection poset of H$\mathcal {H}$. Using the Bogomolov–Gieseker inequality for parabolic bundles, we show that if a∈RH$\mathbf {a}\in \mathbb {R}^{\mathcal {H}}$ is ...
Martin de Borbon, Dmitri Panov
wiley +1 more source
Unitary transformation for Poincaré beams on different parts of Poincaré sphere. [PDF]
Sci Rep, 2020 Sun X +6 more
europepmc +1 more source
Asymptotic Analysis of the Static Bidomain Model for Pulsed Field Cardiac Ablation
Mathematical Methods in the Applied Sciences, Volume 49, Issue 4, Page 2510-2531, 15 March 2026.ABSTRACT Cardiac arrhythmias are caused by faulty electrical signals in the heart, which lead to chaotic wave propagation and impaired cardiac function. This work focuses on a non‐thermal ablation technique based on electroporation (EP), a promising method for treating arrhythmias, called pulsed field ablation (PFA).
Annabelle Collin +2 more
wiley +1 more source
Role of scattering and birefringence in phase retardation revealed by locus of Stokes vector on Poincaré sphere. [PDF]
J Biomed Opt, 2020 Borovkova M +3 more
europepmc +1 more source
A Higher-order poincaré ellipsoid representation for non-cylindrical vector beams
Discover Applied SciencesThe Higher-Order Poincaré Sphere (HOPS) provides a powerful geometrical tool for representing vector beams as points on the surface of a unitary sphere. Since a particular position on the surface represents any spatial mode regardless of its shape, this ...
Dayver Daza-Salgado +4 more
doaj +1 more source
Far-Field Topological Structure of the Second Harmonic from Higher-Order Poincaré Sphere Beam
PhotonicsIn this paper, the far-field topological structures (FFTSs) of the second harmonic (SH) from higher-order Poincaré sphere (HOPS) beams, including circularly polarized vortex beams (VBs), cylindrically vector beams (CVBs) and elliptically polarized CVBs ...
Yangyang Li +6 more
doaj +1 more source
Fine-structure mapping of structured Laguerre-Gaussian beam states on the orbital Poincaré sphere
Компьютерная оптикаElements of a 4D symplectic matrix P of second-order intensity moments are theoretically found and experimentally measured for paraxial structured Laguerre-Gaussian (sLG) beams with two control parameters—the amplitude e and phaseq. It is shown that only
A.V. Volyar +2 more
doaj +1 more source
Propagation-induced Frequency-dependent Polarization Properties of Fast Radio Burst
The Astrophysical JournalFrequency-dependent polarization properties provide crucial insights into the radiation mechanisms and magnetic environments of fast radio bursts (FRBs).
Wei-Yang Wang +8 more
doaj +1 more source
Journal of High Energy PhysicsThe relation between two branches of solutions (radiative and subradiative) of wave equations on Minkowski spacetime is investigated, for any integer spin, in flat Bondi coordinates where remarkable simplifications occur and allow for exact boundary-to ...
Xavier Bekaert, S. I. Aadharsh Raj
doaj +1 more source