Forced Symmetry Breaking from SO(3) to SO(2) for Rotating Waves on the Sphere

We consider a small SO(2)-equivariant perturbation of a reaction-diffusion system on the sphere, which is equivariant with respect to the group SO(3) of all rigid rotations. We consider a normally hyperbolic SO(3)-group orbit of a rotating wave on the sphere that persists to a normally hyperbolic SO(2)-invariant manifold $M(\epsilon)$. We investigate the effects of this forced symmetry breaking by studying the perturbed dynamics induced on $M(\epsilon)$ by the above reaction-diffusion system. We prove that depending on the frequency vectors of the rotating waves that form the relative equilibrium SO(3)u_{0}, these rotating waves will give SO(2)-orbits of rotating waves or SO(2)-orbits of modulated rotating waves (if some transversality conditions hold). The orbital stability of these solutions is established as well. Our main tools are the orbit space reduction, Poincare map and implicit function theorem

The Role of Personal and Immune Variables in the Development of Co-Morbid Affective and Related Psychopathological Syndromes in Partial Epilepsies in Relation to Handedness

The current study was performed in order to find the influence of premorbid personality traits and immune variables on psychopathological constructs including affective and related syndromes in patients with epilepsy separately for right-handers and left-handers. Ninety two patients with epilepsy have been included into the study. There were 85 right-handers and 7 left-handers. Assessment of psychopathological status of patients has been performed by using of Symptom Check List −90 (SCL-90) and the Hamilton rating scales for Depression and Anxiety. The Munich Personality test (MPT) was used for the assessment of personality trait. The amounts of different lymphocytes clusters were calculated. The multiple stepwise regression analysis was used to find the relationships between personality, immunity variables and affective and related psychopathological syndromes separately for right-handers and left-handers.In the right-handers significant relationships between the Neuroticism level (MPT) and value of HAM-D, Depression construct (SCL-90), Anxiety (SCL-90), Obsessions (SCL-90) and Phobia construct (SCL-90) have been obtained. In the left-handers stochastically significant correlations between Regulatory Index (CD4/CD8) with Depression construct (SCL-90) and Obsession construct (SCL-90) were revealed. Premorbid personality traits determine the affective, anxiety, obsessive and phobia syndromes strictly in right-handed patients with epilepsy, while immunity variables (CD4/CD) quite the contrary predispose to affective and obsessive syndromes strictly in left-handed patients

Researchers on ice? How the COVID-19 pandemic has impacted Antarctic researchers

The COVID-19 pandemic and pandemic-related measures have impacted the lives and work-related activities of Antarctic researchers. To explore these impacts, we designed, piloted and disseminated an online survey in English, Russian, Spanish and Chinese in late 2020 and early 2021. The survey explored how the pandemic affected the productivity of Antarctic researchers, their career prospects and their mental wellbeing. Findings exposed patterns of inequities. For instance, of the 406 unique responses to the survey, women appeared to have been affected more adversely than men, especially in relation to mental health, and early-career researchers were disadvantaged more than their mid- or late-career colleagues. Overall, a third of the research participants reported at least one major negative impact from the pandemic on their mental health. Approximately half of the participants also mentioned that the COVID-19 pandemic had some positive effects, especially in terms of the advantages that working from home brought and opportunities to attend events, network or benefit from training workshops online. We conclude with a series of recommendations for science administrators and policymakers to mitigate the most serious adverse impacts of the pandemic on Antarctic research communities, with implications for other contexts where scientific activities are conducted under extreme circumstances

Clinical neuropsychologic characteristics of psychoorganic syndrome in children’s epilepsy

This work describes dynamics in clinical neuropsychologic characteristics of psychoorganic syndrome in children’s epilepsy. 156 children with epilepsy have been studied using clinical-anamnestic, clinical-psychopathologic, clinical-dynamic and neuropsychologic methods. We have analyzed clinical features of psychoorganic syndrome depending on time of epilepsy debut and studied dynamics of mental disorder. It was found that the earlier an epilepsy debut happens, the more serious mental disorders a child has. Clinical presentation of manifestation and generation of psychoorganic syndrome depends on stages of ontogenetic development. Neuropsychologic challenge correlates with clinical presentation of psychoorganic syndrome.Цель работы: В работе представлена динамика клинико-нейропсихологических характеристик психоорганического синдрома при эпилепсии у детей. С помощью клинико-анамнестического, клинико-психопатологического, клинико-динамического и нейропсихологического методов изучено 156 детей, страдающих эпилепсией. Были проанализированы клинические особенности психоорганического синдрома в зависимости от времени дебюта эпилепсии и рассмотрена динамика становления психической патологии. Определено, что чем раньше дебют эпилепсии, тем тяжелее психические нарушения. Клиническая картина манифестации и становления психоорганического синдрома зависели от этапов онтогенетического развития. Нейропсихологическая симптоматика коррелировала с клинической картиной психо-органического синдрома

Spiral anchoring in anisotropic media with multiple inhomogeneities: a dynamical system approach

Various PDE models have been suggested in order to explain and predict the dynamics of spiral waves in excitable media. In two landmark papers, Barkley noticed that some of the behaviour could be explained by the inherent Euclidean symmetry of these models. LeBlanc and Wulff then introduced forced Euclidean symmetry-breaking (FESB) to the analysis, in the form of individual translational symmetry-breaking (TSB) perturbations and rotational symmetry-breaking (RSB) perturbations; in either case, it is shown that spiral anchoring is a direct consequence of the FESB. In this article, we provide a characterization of spiral anchoring when two perturbations, a TSB term and a RSB term, are combined, where the TSB term is centered at the origin and the RSB term preserves rotations by multiples of $\frac{2\pi}{\jmath^*}$, where $\jmath^*\geq 1$ is an integer. When $\jmath^*>1$ (such as in a modified bidomain model), it is shown that spirals anchor at the origin, but when $\jmath^* =1$ (such as in a planar reaction-diffusion-advection system), spirals generically anchor away from the origin.Comment: Revised versio

МИНЕРАЛЬНАЯ ПЛОТНОСТЬ КОСТИ ПОСЛЕ ПЕРЕСАДКИ ПЕЧЕНИ

Bone mineral density (BMD) was estimated twice in 18 recipents of ortotopic liver transplantation. There was decreased BMD in axial so as in peripheral skeleton in early time and in vertebral or hip Ward triangle in late time following transplantation being lower in primary biliary cirrosis then in cirrosis following chronic virus hepatitis despite tacrolimus immunosupression without prednisolon. Tacrolimus immunosupression with prednisolon in primary biliary cirrosis patients in late postoperative time was associated with hard BMD lowering which correlated with glucocorticoid therapy duration and prednisolon cumulative dosis. Минеральная плотность костной ткани (МПК) исследована повторно у 18 пациентов (36 наблюдений) после ортотопической трансплантации печени (ОТП). У реципиентов с первичным билиарным циррозом (ПБЦ) и с циррозом печени в исходе хронических вирусных гепатитов на фоне лечения такролимусом (без преднизолона) МПК в ранние сроки после ОТП снижена в области и осевого, и периферического скелета, притом у реципиентов с ПБЦ в достоверно большей степени, а в отдаленные сроки – только в поясничных позвонках или в треугольнике Варда. Иммуносупрессия такролимусом в комбинации с преднизолоном у реципиентов с ПБЦ в отдаленные сроки после ОТП ассоциируется со значительным снижением МПК во всех отделах скелета, выраженность которого определяется продолжительностью терапии преднизолоном и его кумулятивными дозами.

Non-Steroidal Anti-Inflammatory Drugs and Cognitive Function: Are Prostaglandins at the Heart of Cognitive Impairment in Dementia and Delirium ?

Studies of non-steroidal anti-inflammatory drugs (NSAIDs) in rheumatoid arthritis imply that inflammation is important in the development of Alzheimer’s disease (AD). However, these drugs have not alleviated the symptoms of AD in those who have already developed dementia. This suggests that the primary mediator targeted by these drugs, PGE2, is not actively suppressing memory function in AD. Amyloid-β oligomers appear to be important for the mild cognitive changes seen in AD transgenic mice, yet amyloid immunotherapy has also proven unsuccessful in clinical trials. Collectively, these findings indicate that NSAIDs may target a prodromal process in mice that has already passed in those diagnosed with AD, and that synaptic and neuronal loss are key determinants of cognitive dysfunction in AD. While the role of inflammation has not yet become clear, inflammatory processes definitely have a negative impact on cognitive function during episodes of delirium during dementia. Delirium is an acute and profound impairment of cognitive function frequently occurring in aged and demented patients exposed to systemic inflammatory insults, which is now recognised to contribute to long-term cognitive decline. Recent work in animal models is beginning to shed light on the interactions between systemic inflammation and CNS pathology in these acute exacerbations of dementia. This review will assess the role of prostaglandin synthesis in the memory impairments observed in dementia and delirium and will examine the relative contribution of amyloid, synaptic and neuronal loss. We will also discuss how understanding the role of inflammatory mediators in delirious episodes will have major implications for ameliorating the rate of decline in the demented population