715 research outputs found

    Desynchronizing two oscillators while stimulating and observing only one

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    Synchronization of two or more self-sustained oscillators is a well-known and studied phenomenon, appearing both in natural and designed systems. In some cases, the synchronized state is undesired, and the aim is to destroy synchrony by external intervention. In this paper, we focus on desynchronizing two self-sustained oscillators by short pulses delivered to the system in a phase-specific manner. We analyze a non-trivial case when we cannot access both oscillators but stimulate only one. The following restriction is that we can monitor only one unit, be it a stimulated or non-stimulated one. First, we use a system of two coupled Rayleigh oscillators to demonstrate how a loss of synchrony can be induced by stimulating a unit once per period at a specific phase and detected by observing consecutive inter-pulse durations. Next, we exploit the phase approximation to develop a rigorous theory formulating the problem in terms of a map. We derive exact expressions for the phase -- isostable coordinates of this coupled system and show a relation between the phase and isostable response curves to the phase response curve of the uncoupled oscillator. Finally, we demonstrate how to obtain phase response information from the system using time series and discuss the differences between observing the stimulated and unstimulated oscillator

    High-order phase reduction for coupled 2D oscillators

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    Phase reduction is a general approach to describe coupled oscillatory units in terms of their phases, assuming that the amplitudes are enslaved. For such a reduction, the coupling should be small, but one also expects the reduction to be valid for finite coupling. This paper presents a general framework allowing us to obtain coupling terms in higher orders of the coupling parameter for generic two-dimensional oscillators and arbitrary coupling terms. The theory is illustrated with an accurate prediction of Arnold's tongue for the van der Pol oscillator exploiting higher-order phase reduction

    Taiwan's Nationalistic Politics and Its Difficult 'Status Quo'

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    Taiwan’s growing calls for independence have provoked China and heightened the risk of military conflict in the region. This paper addresses two issues: first, it seeks to provide a short historical overview of the development of Taiwanese nationalistic self-assertion; second, it questions the commonly held notion of keeping the ‘status quo’, which is in effect always changing and dynamic. The paper uses a historical-institutional framework for its interpretation. It explores the origin and rise of Taiwanese nationalism in its relationship to Taiwan’s past, and the changing geo-political contexts in which it is situated. It then analyses the importance of electoral institutions and the struggles to broaden poltical participation and legitimation. Several disparate sources of Taiwanese identity are also discussed, namely: (i) Taiwan as a frontier territory of the Manchu Empire, which was later colonized and modernized by the Japanese; (ii) the transformation of the ROC regime, its indigenization and grounding in Taiwan in the context of its long separation from China and its international isolation. This indigenization process has been gradually accomplished through electoral struggles and by revising the electoral system and the constitution

    Morphometrische Gehäuseunterschiede bei Lit- torina littorea an verschieden exponierten Standorten

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    The common periwinkle Littorina littorea is a commonly found gastropod of the litoral of the northern hemisphere. One of the environmental factors influencing its morphology is the exposition to wave impact. We tested, if and how exposition causes changes in the shell size and thickness of L. littorea. We found, that with decreasing exposition to wave impacts, shell size increases while shell thickness decreases. It is discussed whether wave impact exposition is the main influence factor on shell morphology divergence, as contrary findings have been described for different populations of three Littorina species including L. littorea.Das Immergrüne Littorina littorea ist eine häufig vorkommende Gastropode des Litorals der nördlichen Hemisphäre. Einer der Umweltfaktoren, die seine Morphologie beeinflussen, ist die Einwirkung von Wellen. Wir haben getestet, ob und wie die Exposition zu Veränderungen der Schalengröße und -dicke von L. littorea führt. Wir haben festgestellt, dass mit abnehmender Exposition gegenüber Welleneinschlägen die Schalengröße zunimmt, während die Schalendicke abnimmt. Es wird diskutiert, ob die Wellenschlagexposition der Haupteinflussfaktor auf die Divergenz der Schalenmorphologie ist, da für verschiedene Populationen von drei Littorina-Arten einschließlich L. littorea gegensätzliche Ergebnisse beschrieben wurden.Peer Reviewe

    Double and triple sequential shocks reduce ventricular defibrillation threshold in dogs with and without myocardial infarction

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    The role of optimal placement of electrodes and mode of shock delivery from a defibrillator was examined in dogs with and without myocardial infarction. Single, double and triple truncated exponential shocks separated by 1 ms were delivered through various electrode combinations and cardiac vectors after electrical induction of ventricular fibrillation. A single shock through a pathway not incorporating the interventricular septum (catheter electrodes or epicardial patches between anterior and posterior left ventricle) required the highest total energy (22.6 and > 26.4 J, respectively) and peak voltage (1,004 and > 1,094 V, respectively) to terminate ventricular fibrillation. A single shock through a pathway including the interventricular septum required lower total energy and peak voltage to defibrillate.Combinations of two sequential shocks between an intracardiac catheter electrode and anterior left ventricular epicardial patch, between the catheter electrode and subcutaneous extrathoracic plate and between three ventricular epicardial patches all significantly reduced total energy (7.7, 8.7 and 7.8 J, respectively) and peak voltage (424, 436 and 424 V, respectively) needed to defibrillate. Three sequential shocks exerted no significant additional reduction in total energy of the defibrillation threshold than did two sequential shocks. In-farcted canine heart required less peak voltage but not total energy to terminate ventricular fibrillation than did noninfarcted heart. Therefore, two sequential shocks over different pathways reduce both total energy and peak voltage required to terminate ventricular fibrillation

    RENaBack: low back pain patients in rehabilitation—study protocol for a multicenter, randomized controlled trial

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    Background: Millions of people in Germany suffer from chronic pain, in which course and intensity are multifactorial. Besides physical injuries, certain psychosocial risk factors are involved in the disease process. The national health care guidelines for the diagnosis and treatment of non-specific low back pain recommend the screening of psychosocial risk factors as early as possible, to be able to adapt the therapy to patient needs (e.g., unimodal or multimodal). However, such a procedure has been difficult to implement in practice and has not yet been integrated into the rehabilitation care structures across the country. Methods: The aim of this study is to implement an individualized therapy and aftercare program within the rehabilitation offer of the German Pension Insurance in the area of orthopedics and to examine its success and sustainability in comparison to the previous standard aftercare program. The study is a multicenter randomized controlled trial including 1204 patients from six orthopedic rehabilitation clinics. A 2:1 allocation ratio to intervention (individualized and home-based rehabilitation aftercare) versus the control group (regular outpatient rehabilitation aftercare) is set. Upon admission to the rehabilitation clinic, participants in the intervention group will be screened according to their psychosocial risk profile. They could then receive either unimodal or multimodal, together with an individualized training program. The program is instructed in the clinic (approximately 3 weeks) and will continue independently at home afterwards for 3 months. The success of the program is examined by means of a total of four surveys. The co-primary outcomes are the Characteristic Pain Intensity and Disability Score assessed by the German version of the Chronic Pain Grade questionnaire (CPG). Discussion: An improvement in terms of pain, work ability, patient compliance, and acceptance in our intervention program compared to the standard aftercare is expected. The study contributes to provide individualized care also to patients living far away from clinical centers.German Pension Insurance Berlin-Brandenburg and Central GermanyPeer Reviewe

    Datenbank Biomassepotenziale - Erstellung einer Datenbank zur Berechnung regionaler Biomassepotenziale aus dem landwirtschaftlichen Anbau und ausgewählten Reststoffen für den Non-Food-Bereich im Freistaat Sachsen bis zum Jahr 2020

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    Ziele des FuE-Vorhabens waren die Bereitstellung von Daten über die im Freistaat Sachsen bis 2020 regional tatsächlich verfügbaren Potenziale an Biomasse und die Gewinnung von mehr Sicherheit im Hinblick auf die Auswirkungen der Einflussfaktoren, denen diese Potenziale unterliegen. Dazu wurde eine Datenbank zur Berechnung der sächsischen Biomassepotenziale aus der Landwirtschaft und von ausgewählten Reststoffen für den Non-Food-Bereich erarbeitet. Diese ist durch folgende Punkte gekennzeichnet: - Durch die Berücksichtigung von Einflussfaktoren wie regional anzutreffende landwirtschaftliche Standorte, standortabhängige vom Nutzer festzulegende Fruchtfolgen, Ertragsentwicklung, Bevölkerungsentwicklung und verfügbare Ackerflächen werden differenzierte Daten berechnet. - Die Berechnungen können auf drei Ebenen erfolgen: für Sachsen, Regierungsbezirke und je Landkreis. - Es wurden zwei Beispielsszenarien berechnet, an Hand derer die Potenziale bei variierten Annahmen verdeutlicht werden. - Hinweise zur Arbeitsweise der Datenbank wurden in einem Handbuch zusammengestellt. Die Datenbank ermöglicht mit den flexiblen Eingabedaten die Berechnung konkreter regionalspezifischer Daten für das Potenzial aus landwirtschaftlicher Biomasse. Dies verbessert die Voraussetzungen für regionale Planungen von Vorhaben, die Biomasse als Rohstoff beanspruchen, erheblich

    Assessing marine gas emission activity and contribution to the atmospheric methane inventory: A multidisciplinary approach from the Dutch Dogger Bank seep area (North Sea)

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    We present a comprehensive study showing new results from a shallow gas seep area in approximate to 40 m water depth located in the North Sea, Netherlands sector B13 that we call Dutch Dogger Bank seep area. It has been postulated that methane presumably originating from a gas reservoir in approximate to 600 m depth below the seafloor is naturally leaking to the seafloor. Our ship-based subbottom echosounder data indicate that the migrating gas is trapped in numerous gas pockets in the shallow sediments. The gas pockets are located at the boundary between the top of the Late Pliocene section and overlying fine-grained sediments, which were deposited during the early Holocene marine transgression after the last glaciation. We mapped gas emissions during three R/V Heincke cruises in 2014, 2015, and 2016 and repeatedly observed up to 850 flares in the study area. Most of them (approximate to 80%) were concentrated at five flare clusters. Our repeated analysis revealed spatial similarities of seep clusters, but also heterogeneities in emission intensities. A first calculation of the methane released from these clusters into the water column revealed a flow rate of 277 L/min (SD=140), with two clusters emitting 132 and 142 L/min representing the most significant seepage sites. Above these two flare clusters, elevated methane concentrations were recorded in atmospheric measurements. Our results illustrate the effective transport of methane via gas bubbles through a approximate to 40 m water column, and furthermore provide an estimate of the emission rate needed to allow for a contribution to the atmospheric methane concentration

    Ультрадисперсные порошки на основе железа как катализаторы синтеза жидких углеводородов из СО и Н[2]

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    International audienceTo date, uniparental disomy (UPD) with phenotypic relevance is described for different chromosomes and it is likely that additional as yet unidentified UPD phenotypes exist. Due to technical difficulties and limitations of time and resources, molecular analyses for UPD using microsatellite markers are only performed in cases with specific phenotypic features. In this study, we carried out a whole genome UPD screening based on a microarray genotyping technique. Six patients with the diagnosis of both complete or segmental UPD including Prader-Willi syndrome (PWS; matUPD15), Angelman syndrome (AS; patUPD15), Silver-Russell syndrome (SRS; matUPD7), Beckwith-Wiedemann syndrome (BWS; patUPD11p), pseudohypoparathyroidism (PHP; patUPD20q) and a rare chromosomal rearrangement (patUPD2p, matUPD2q), were genotyped using the GeneChip Human Mapping 10K Array. Our results demonstrate the presence of UPD in the patients with high efficiency and reveal clues about the mechanisms of UPD formation. We thus conclude that array based SNP genotyping is a fast, cost-effective, and reliable approach for whole genome UPD screening

    Phase 1 dose-escalation study of the antiplacental growth factor monoclonal antibody RO5323441 combined with bevacizumab in patients with recurrent glioblastoma

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    Background We conducted a phase 1 dose-escalation study of RO5323441, a novel antiplacental growth factor (PlGF) monoclonal antibody, to establish the recommended dose for use with bevacizumab and to investigate the pharmacokinetics, pharmacodynamics, safety/tolerability, and preliminary clinical efficacy of the combination. Methods Twenty-two participants with histologically confirmed glioblastoma in first relapse were treated every 2 weeks with RO5323441 (625 mg, 1250 mg, or 2500 mg) plus bevacizumab (10 mg/kg). A standard 3 + 3 dose-escalation trial design was used. Results RO5323441 combined with bevacizumab was generally well tolerated, and the maximum tolerated dose was not reached. Two participants experienced dose-limiting toxicities (grade 3 meningitis associated with spinal fluid leak [1250 mg] and grade 3 cerebral infarction [2500 mg]). Common adverse events included hypertension (14 participants, 64%), headache (12 participants, 55%), dysphonia (11 participants, 50%) and fatigue (6 participants, 27%). The pharmacokinetics of RO5323441 were linear, over-the-dose range, and bevacizumab exposure was unaffected by RO5323441 coadministration. Modulation of plasmatic angiogenic proteins, with increases in VEGFA and decreases in FLT4, was observed. Dynamic contrast-enhanced/diffusion-weighted MRI revealed large decreases in vascular parameters that were maintained through the dosing period. Combination therapy achieved an overall response rate of 22.7%, including one complete response, and median progression-free and overall survival of 3.5 and 8.5 months, respectively. Conclusion The toxicity profile of RO5323441 plus bevacizumab was acceptable and manageable. The observed clinical activity of the combination does not appear to improve on that obtained with single-agent bevacizumab in patients with recurrent glioblastom
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