34 research outputs found

    Effect of non-zero constant vorticity on the nonlinear resonances of capillary water waves

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    The influence of an underlying current on 3-wave interactions of capillary water waves is studied. The fact that in irrotational flow resonant 3-wave interactions are not possible can be invalidated by the presence of an underlying current of constant non-zero vorticity. We show that: 1) wave trains in flows with constant non-zero vorticity are possible only for two-dimensional flows; 2) only positive constant vorticities can trigger the appearance of three-wave resonances; 3) the number of positive constant vorticities which do trigger a resonance is countable; 4) the magnitude of a positive constant vorticity triggering a resonance can not be too small.Comment: 6 pages, submitte

    Психосоматические соотношения при гастроинтестинальных заболеваниях в практике врача-терапевта

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    We have studied peculiarities of psychosomatic relations in 140 duodenal ulcer (DU) and irritable bowel syndrome (IBS) patients having neurotic and psychic disorders. Analysis of results of clinical-endoscopic, clinical- psychopathological, and psychological methods has revealed polymorphism of psychopathological disorders hampering differential diagnostics and treatment of DU and IBS. This requires a combined approach to therapy of comorbid gastro-intestinal and borderline mental pathologies with both somatotrophic and psychotropic agents.Изучены особенности психосоматических соотношений у 140 больных язвенной болезнью двенадцатиперстной кишки (ЯБ ДПК) и синдромом раздраженного кишечника (СРК) с невротическими и аффективными расстройствами. При анализе результатов клинико-эндоскопического, клинико-психопатологического, психологических методов исследования выявлен полиморфизм психопатологических расстройств, затрудняющий дифференциальную диагностику и лечение ЯБ ДПК и СРК, что требует комплексного подхода к терапии коморбидной гастроинтестинальной и пограничной психической патологии, включающей наряду с соматотропными препаратами средства психотропного действия

    Laplace Invariants for General Hyperbolic Systems

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    We consider the generalization of Laplace invariants to linear differential systems of arbitrary rank and dimension. We discuss completeness of certain subsets of invariants

    Kolmogorov turbulence, Anderson localization and KAM integrability

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    The conditions for emergence of Kolmogorov turbulence, and related weak wave turbulence, in finite size systems are analyzed by analytical methods and numerical simulations of simple models. The analogy between Kolmogorov energy flow from large to small spacial scales and conductivity in disordered solid state systems is proposed. It is argued that the Anderson localization can stop such an energy flow. The effects of nonlinear wave interactions on such a localization are analyzed. The results obtained for finite size system models show the existence of an effective chaos border between the Kolmogorov-Arnold-Moser (KAM) integrability at weak nonlinearity, when energy does not flow to small scales, and developed chaos regime emerging above this border with the Kolmogorov turbulent energy flow from large to small scales.Comment: 8 pages, 6 figs, EPJB style

    Коморбидность ахалазии пищевода, смешанной тревожной и депрессивной реакции у пациентки молодого возраста: проблемы диагностики и лечения

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    Achalasia cardia (“cardiospasm”, “phrenospasm”, “dolichoesophagus”, “megaesophagus”, “stenosis of cardia”) represents a primary impairment of esophageal motor function associated with impaired lower esophageal sphincter relaxation and peristalsis defects of the thoracic esophagus. It is diagnosed at the age of 25 to 60 years, making up to 20% of all diseases of the esophagus, and is characterized by a triad of symptoms: dysphagia, regurgitation and chest pain when swallowing. In most cases the first manifestations of achalasia are preceded by stress situations in the anamnesis that complicates the differential diagnosis of psychogenic esophageal spasm. The presented clinical case illustrates difficulties of early diagnosis of achalasia cardia in a young femalepatient with severe anxiety and depressive symptoms which develop under conditions of chronic stressful situations in the family or at work. The issues of interdisciplinary interaction of health professionals (physician, gastroenterologist, psychiatrist, psychotherapist, and surgeon) on the course of examination and management of patients with comorbid physical and mental pathology are discussed. The efficiency of the integrative approach to treatment and rehabilitation with the use of modern reconstructive surgical interventions as well as conservative methods of therapy, psychopharmacotherapy and personality-oriented psychotherapy proves the relevance of studying psychosomatic aspects of achalasia cardia.Ахалазия кардии (кардиоспазм, френоспазм, долихоэзофагус, мегаэзофагус, кардиостеноз) представляет собой первичное нарушение двигательной функции пищевода, связанное с ухудшением расслабления нижнего пищеводного сфинктера и дефектами перистальтики его грудного отдела. Диагностируется в возрасте 25–60 лет, составляя до 20% случаев всех заболеваний пищевода, характеризуется триадой симптомов: дисфагией, регургитацией, загрудинными болями при глотании. В большинстве случаев первым проявлениям ахалазии предшествуют стрессовые ситуации в анамнезе, что затрудняет дифференциальную диагностику с психогенным эзофагоспазмом. Представленный клинический случай иллюстрирует трудности диагностики ахалазии кардиального отдела пищевода у женщины молодого возраста с выраженной тревожной и депрессивной симптоматикой, развившейся в условиях хронической стрессовой ситуации семейного и производственного плана. Обсуждаются вопросы междисциплинарного взаимодействия специалистов (терапевта, гастроэнтеролога, психиатра, психотерапевта, хирурга) по тактике обследования и ведения больной с коморбидной соматической и психической патологией. Эффективность интегративного подхода к лечению и реабилитации с использованием современных реконструктивных хирургических вмешательств, а также консервативных методов терапии, психофармакотерапии, личностно ориентированной психотерапии свидетельствует об актуальности изучения психосоматических аспектов ахалазии кардии

    Discrete and mesoscopic regimes of finite-size wave turbulence

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    Bounding volume results in discreteness of eigenmodes in wave systems. This leads to a depletion or complete loss of wave resonances (three-wave, four-wave, etc.), which has a strong effect on wave turbulence (WT) i.e., on the statistical behavior of broadband sets of weakly nonlinear waves. This paper describes three different regimes of WT realizable for different levels of the wave excitations: discrete, mesoscopic and kinetic WT. Discrete WT comprises chaotic dynamics of interacting wave "clusters" consisting of discrete (often finite) number of connected resonant wave triads (or quarters). Kinetic WT refers to the infinite-box theory, described by well-known wave-kinetic equations. Mesoscopic WT is a regime in which either the discrete and the kinetic evolutions alternate or when none of these two types is purely realized. We argue that in mesoscopic systems the wave spectrum experiences a sandpile behavior. Importantly, the mesoscopic regime is realized for a broad range of wave amplitudes which typically spans over several orders on magnitude, and not just for a particular intermediate level
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