Results 61 to 70 of about 6,620 (262)

Parkinson Disease Subtype Stability and Eventual Convergence

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Previous research identified distinct Parkinson disease (PD) clinical subtypes of “Motor Only,” “Psychiatric & Motor,” and “Cognitive & Motor” based on comprehensive, multidomain classification. Whether these subtypes reflect distinct trajectories or progressive disease stages remains unknown.
Laura M. Rosok, Christina N. Lessov‐Schlaggar, Abdulmunaim M. Eid, Erin R. Foster, Baijayanta Maiti, Hailee Domash, Helen Hwang, Richard J. Perrin, Paul T. Kotzbauer, Joel S. Perlmutter, Meghan C. Campbell   +10 more
wiley   +1 more source

Nonlinear Perturbations and Weak Shock Waves in Isentropic Atmospheres

The Astrophysical Journal
Acoustic perturbations to stellar envelopes can lead to the formation of weak shock waves via nonlinear wave steepening. Close to the stellar surface, the weak shock wave increases in strength and can potentially lead to the expulsion of part of the ...
Tamar Faran, Christopher D. Matzner, Eliot Quataert   +2 more
doaj   +1 more source

Efficient method for solving highly oscillatory ordinary differential equations with applications to physical systems

Physical Review Research, 2020
We present a numerical routine (oscode) with a C++ and Python interface for the efficient solution of one-dimensional, second-order, ordinary differential equations with rapidly oscillating solutions.
F. J. Agocs, W. J. Handley, A. N. Lasenby, M. P. Hobson   +3 more
doaj   +1 more source

Homoclinic Solutions and Chaos in Ordinary Differential Equations with Singular Perturbations [PDF]

Transactions of the American Mathematical Society, 1998
Ordinary differential equations are considered which contain a singular perturbation. It is assumed that when the perturbation parameter is zero, the equation has a hyperbolic equilibrium and homoclinic solution. No restriction is placed on the dimension of the phase space or on the dimension of intersection of the stable and unstable manifolds.
openaire   +1 more source

Employment Trajectories of Patients With Systemic Lupus Erythematosus and Factors Driving Transitions Between States

Arthritis Care &Research, EarlyView.
Objective Systemic lupus erythematosus (SLE) significantly impacts employment capacity. This study aimed to investigate the impact of burden of disease activity, damage, and treatment on employment outcomes and transitions in patients with SLE. Methods Using data from a single center, we analyzed employment transitions, adjusted mean disease activity ...
Javier Mencia‐Ledo, Zahi Touma, Laura Whittall Garcia, Dafna D. Gladman, Behdin Nowrouzi‐Kia   +4 more
wiley   +1 more source

Prevalence of Dietary Supplement Use and Potential Medication Interactions Among Adults With Systemic Lupus Erythematosus

Arthritis Care &Research, EarlyView.
Objective The aim of this study was to characterize the prevalence and correlates of dietary supplement use, identify commonly used supplements, and evaluate potential supplement–medication interactions among adults with systemic lupus erythematosus (SLE).
Sarah L. Patterson, Russell Ellyson, Jessica Fitzpatrick, Ghizlane Yaakoubi, Bradley Pearce, S. Sam Lim, Jinoos Yazdany, Laura C. Plantinga   +7 more
wiley   +1 more source

Sound wave propagation problems new perturbation methodology

Archives of Acoustics, 2014
The aim of the paper is to present applications of the new algebraic system theory in acoustic problems. Elements of new types of perturbed ordinary and partial differential equations are discussed.
Jerzy Skrzypczyk, A. Winkler-Skalna
doaj  

Spacetime perspective of gravitational lensing in perturbed cosmologies

Scientific Reports
We develop the spacetime approach to gravitational lensing by spherically symmetric perturbations of flat, cosmological constant-dominated Friedman-Robertson-Walker metrics.
Thomas P. Kling, Sophia MacQueen Pooler
doaj   +1 more source

Model selection in the reconstruction of regulatory networks from time-series data

BMC Research Notes, 2009
Background A widely used approach to reconstruct regulatory networks from time-series data is based on the first-order, linear ordinary differential equations.
Barillot Emmanuel, Novikov Eugene
doaj   +1 more source

Perturbations of nonlinear systems of ordinary differential equations

Journal of Mathematical Analysis and Applications, 1984
Along with the n dimensional system (1) \(y'=f(t,y)\) the perturbed system (2) \(x'=f(t,x)+g(t,x)\) is considered. Certain refined assumptions are made about estimates of the fundamental matrix solution of the variational system with respect to a solution of system (1), and about g. (The function g need not be ''small'', it may be sublinear or linear.)
openaire   +2 more sources