Nonlinear Maxwell Equations

A new relativistic invariant version of nonlinear Maxwell equations is offerred. Some properties of these equations are considered.Comment: 6 pages, LaTe

Model of large scale man-machine systems with an application to vessel traffic control

Mathematical models are discussed to deal with complex large-scale man-machine systems such as vessel (air, road) traffic and process control systems. Only interrelationships between subsystems are assumed. Each subsystem is controlled by a corresponding human operator (HO). Because of the interaction between subsystems, the HO has to estimate the state of all relevant subsystems and the relationships between them, based on which he can decide and react. This nonlinear filter problem is solved by means of both a linearized Kalman filter and an extended Kalman filter (in case state references are unknown and have to be estimated). The general model structure is applied to the concrete problem of vessel traffic control. In addition to the control of each ship, this involves collision avoidance between ship

On polymer expansions for generalized Gibbs lattice systems of oscillators with ternary interaction

We propose a new short proof of the convergence of high-temperature polymer expansions in the thermodynamic limit of canonical correlation functions for classical and quantum Gibbs lattice systems of oscillators interacting via pair and ternary potentials and nonequilibrium stochastic systems of oscillators interacting via a pair potential with Gibbsian initial correlation functions.Запропоновано нове коротке доведення з6іжності високотемпературних полімєрних розкладів термодинамiчної границі канонічних кореляційних функцій ґраткових класичних та квантових гіббсівських систем осциляторів, що взаємодіють завдяки парному та тернарному потенціалам, а також нерівноважних стохастичних систем осциляторів, які взаємодіють завдяки парному потенціалу з гіббсівськими початковими кореляційними функціями

Periodic and bounded solutions of the Coulomb equation of motion of two and three point charges with equilibrium in the line

Periodic and bounded solutions of the Coulomb equation of motion in the line are obtained for two and three identical negative point charges in the fields of two and three symmetrically located fixed point charges. The systems possess equilibrium configurations. The Lyapunov, Siegel, Moser, and Weinstein theorems are applied.Знайдено періодичні та обмежені розв'язки рівнянь руху Кулона на прямій для двох та трьох однакових негативних точкових зарядів у полі двох та трьох точкових фіксованих зарядів, що симетрично розташовані. Ці системи мають рівноважні стани. При цьому використано теореми Ляпунова, Зігеля, Мозера та Вайнстайна

Long-range order in Gibbs lattice classical linear oscillator systems

The existence of the ferromagnetic long-range order (lro) is proved for Gibbs classical lattice systems of linear oscillators interacting via a strong polynomial pair nearest neighbor (n-n) ferromagnetic potential and other (nonpair) potentials that are weak if they are not ferromagnetic. A generalized Peierls argument and two different contour bounds are our main tools.Доведено існування феромагнітного далекого порядку для гіббсівської класичної ґраткової системи лінійних осциляторів, що взаємодіють завдяки сильному парному поліноміальному феромагнітному потенціалу близьких сусідів та іншим (непарним) потенціалам, які слабкі, якщо не феромагнітні. При цьому використано узагальнений аргумент Пайєрлса та дві контурні нерівності

On Gibbs quantum and classical particle systems with three-body forces

For equilibrium quantum and classical systems of particles interacting via ternary and pair (nonpositive) infinite-range potentials, a low activity convergent cluster expansion for their grand canonical reduced density matrices and correlation functions is constructed in the thermodynamic limit.Для рівноважних квантових та класичних систем частинок, що взаємодіють завдяки тернарному i парному (непозитивним) далекосяжним потенціалам, побудовано кластерний розклад для їх редукованих матриць щільності та кореляційних функцій великого канонічного ансамблю, збіжний при низьких активностях у термодинамічній границі

The biomechanical importance of the scaphoid-centrale fusion during simulated knuckle-walking and its implications for human locomotor evolution

© 2020, The Author(s). Inferring the locomotor behaviour of the last common ancestor (LCA) of humans and African apes is still a divisive issue. An African great-ape-like ancestor using knuckle-walking is still the most parsimonious hypothesis for the LCA, despite diverse conflicting lines of evidence. Crucial to this hypothesis is the role of the centrale in the hominoid wrist, since the fusion of this bone with the scaphoid is among the clearest morphological synapomorphies of African apes and hominins. However, the exact functional significance of this fusion remains unclear. We address this question by carrying out finite element simulations of the hominoid wrist during knuckle-walking by virtually generating fused and unfused morphologies in a sample of hominoids. Finite element analysis was applied to test the hypothesis that a fused scaphoid-centrale better withstands the loads derived from knuckle-walking. The results show that fused morphologies display lower stress values, hence supporting a biomechanical explanation for the fusion as a functional adaptation for knuckle-walking. This functional interpretation for the fusion contrasts with the current inferred positional behaviour of the earliest hominins, thus suggesting that this morphology was probably retained from an LCA that exhibited knuckle-walking as part of its locomotor repertoire and that was probably later exapted for other functions

Cytokines and therapy in COPD: a promising combination?

COPD is a major health problem, with patients showing a progressively declining, largely irreversible, change in lung function. This is associated with chronic airways inflammation and structural remodeling, including loss of alveolar walls, and goblet cell metaplasia with mucus hypersecretion. Inflammatory cells may contribute to the airway remodeling via secretion of proteases, fibrotic or mitogenic growth factors, and cytokines. In turn, airway remodeling may contribute to the clinical symptoms of COPD. Currently available therapies are directed to improvement of clinical symptoms and reduction of the airways inflammation. The commonly used glucocorticosteroids are expected to reduce the inflammation by acting on kinases or transcription factors necessary for expression of pro-inflammatory cytokines or chemokines. However, several long-term and short-term studies showed that glucocorticosteroids are rather ineffective in improving lung function and reducing the airway inflammation in patients with COPD. New therapeutic strategies may reduce the inflammation and alleviate the clinical symptoms of COPD. Tumor necrosis factor-alpha, interleukin-8, and monocyte chemoattractant protein-1 are important chemotactic proteins for macrophages and neutrophils, the predominant inflammatory cells associated with COPD. As lung levels of these cytokines are higher in COPD compared to non-COPD patients, they may represent targets for novel therapies

Kinetic Factors in the Tooth-Plaque-Saliva Model Systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68129/2/10.1177_00220345740530021001.pd

Problems resulting from the use of live attenuated poliomyelitis virus type I in a mass campaign in a large urban area

No Abstrac