Heteroclinic cycles and chaos in a system of four identical phase oscillators with global biharmonic coupling

We study a system of four identical globally coupled phase oscillators with biharmonic coupling function. Its dimension and the type of coupling make it the minimal system of Kuramoto-type (both in the sense of the phase space's dimension and the number of harmonics) that supports chaotic dynamics. However, to the best of our knowledge, there is still no numerical evidence for the existence of chaos in this system. The dynamics of such systems is tightly connected with the action of the symmetry group on its phase space. The presence of symmetries might lead to an emergence of chaos due to scenarios involving specific heteroclinic cycles. We suggest an approach for searching such heteroclinic cycles and showcase first examples of chaos in this system found by using this approach.Comment: 18 pages, 8 figure

The LIFE TRIAD of emergency general surgery

Emergency General Surgery (EGS) was identified as multidisciplinary surgery performed for traumatic and non-traumatic acute conditions during the same admission in the hospital by general emergency surgeons and other specialists. It is the most diffused surgical discipline in the world. To live and grow strong EGS necessitates three fundamental parts: emergency and elective continuous surgical practice, evidence generation through clinical registries and data accrual, and indications and guidelines production: the LIFE TRIAD.Peer reviewe

A pandemic recap : lessons we have learned

On January 2020, the WHO Director General declared that the outbreak constitutes a Public Health Emergency of International Concern. The world has faced a worldwide spread crisis and is still dealing with it. The present paper represents a white paper concerning the tough lessons we have learned from the COVID-19 pandemic. Thus, an international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making. With the present paper, international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making.Non peer reviewe

Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

Using probabilistic fuzzy models for the prediction of functional failures of microwave LSI with radiation exposure

The article presents an analysis of microwave LSI behavior under radiation exposure at the functional-logical level of description. The analysis is based on fuzzy digital automaton and topological probabilistic models of workability assessment. It is shown that in certain cases both deterministic and non-deterministic failures are typical. Each operation threshold in logic elements under radiation influence has a zone of uncertainty and can be expressed quantitatively by a fuzzy number. This case, the real nature of microwave LSI radiation behavior is determined by the specific ratio of radiation-sensitive parameters of its elements and by taking into account the influence of their statistical scatter. Methods are proposed for simulating failures of microwave LSI under radiation exposure that are based on the model of a fuzzy digital Brauer automaton and a probabilistic reliability automaton

Making the smart city: technologies, experiences, and future perspectives

The authors consider the problem of the conceptual the development of “smart cities” in the scholarly literature of foreign and Russian scientists. Based on published literature, the authors classify the concepts of “smart cities” in order to achieve greater clarity of the subject under consideration. Key characteristics of “smart cities” are also considered in the main areas of urban life: energy, water supply, transport, security, services, integration, management

Владимир Андреевич Успенский (27.11.1930-27.06.2018)

International audienceThe genre of the journal Uspekhi Matematicheskikh Nauk1 suggests that we should mainly review the mathematical results of Vladimir Uspensky. However, the whole of his personality and the scope of his activities oblige us to take a broader view. He was an outstanding mathematician, but this also manifested itself in diverse areas where he was active and in his results even outside mathematics. We will also discuss these areas in our survey. During Uspensky’s lifetime no tribute paper dedicated to him appeared in this journal, and this makes it particularly important to (finally) publish a biography of him as a scholar in Uspekhi Matematicheskikh NaukСам жанр журнала "Успехи математических наук" предполагает обзор прежде все-го математических результатов Владимира Андреевича Успенского. Однако вся его личность и деятельность обязывают к более широкому взгляду на вещи. Владимир Андреевич был выдающимся математиком, и это проявлялось в различных сферах его деятельности и её результатах и вне математики. Об этих сферах также будет идти речь в нашем обзоре. При жизни В. А. Успенский обходился без юбилейных статей в "Успехах". Это делает особенно важным опубликовать, хотя и с опозданием, его биографию как учёного в УМН