Collinear helium under periodic driving: stabilization of the asymmetric stretch orbit

The collinear eZe configuration of helium, with the electrons on opposite sides of the nucleus, is studied in the presence of an external electromagnetic (laser or microwave) field. We show that the classically unstable "asymmetric stretch" orbit, on which doubly excited intrashell states of helium with maximum interelectronic angle are anchored, can be stabilized by means of a resonant driving where the frequency of the electromagnetic field equals the frequency of Kepler-like oscillations along the orbit. A static magnetic field, oriented parallel to the oscillating electric field of the driving, can be used to enforce the stability of the configuration with respect to deviations from collinearity. Quantum Floquet calculations within a collinear model of the driven two-electron atom reveal the existence of nondispersive wave packets localized on the stabilized asymmetric stretch orbit, for double excitations corresponding to principal quantum numbers of the order of N > 10.Comment: 13 pages, 12 figure

Comparison of Effects of Ivabradine versus Carvedilol in Murine Model with the Coxsackievirus B3-Induced Viral Myocarditis

BACKGROUND: Elevated heart rate is associated with increased cardiovascular morbidity. The selective I(f) current inhibitor ivabradine reduces heart rate without affecting cardiac contractility, and has been shown to be cardioprotective in the failing heart. Ivabradine also exerts some of its beneficial effects by decreasing cardiac proinflammatory cytokines and inhibiting peroxidants and collagen accumulation in atherosclerosis or congestive heart failure. However, the effects of ivabradine in the setting of acute viral myocarditis and on the cytokines, oxidative stress and cardiomyocyte apoptosis have not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: The study was designed to compare the effects of ivabradine and carvedilol in acute viral myocarditis. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of ivabradine and carvedilol (a nonselective β-adrenoceptor antagonist) on myocardial histopathological changes, cardiac function, plasma noradrenaline, cytokine levels, cardiomyocyte apoptosis, malondialdehyde and superoxide dismutase contents were studied. Both ivabradine and carvedilol similarly and significantly reduced heart rate, attenuated myocardial lesions and improved the impairment of left ventricular function. In addition, ivabradine treatment as well as carvedilol treatment showed significant effects on altered myocardial cytokines with a decrease in the amount of plasma noradrenaline. The increased myocardial MCP-1, IL-6, and TNF-α. in the infected mice was significantly attenuated in the ivabradine treatment group. Only carvedilol had significant anti-oxidative and anti-apoptoic effects in coxsackievirus B3-infected mice. CONCLUSIONS/SIGNIFICANCE: These results show that the protective effects of heart rate reduction with ivabradine and carvedilol observed in the acute phase of coxsackievirus B3 murine myocarditis may be due not only to the heart rate reduction itself but also to the downregulation of inflammatory cytokines

The first year of operation of CologneAMS; performance and developments

In this contribution we report on the measurements performed so far at CologneAMS and on the quality which has been obtained for the isotopes 10Be, 14C and 26Al. We also describe the procedure developed to measure plutonium-isotopes at CologneAMS and first results for 239,240,242Pu are presented. In addition we report on modifications made on our new TOF device with beam profile capabilities

The first year of operation of CologneAMS; performance and developments

In this contribution we report on the measurements performed so far at CologneAMS and on the quality which has been obtained for the isotopes 10Be, 14C and 26Al. We also describe the procedure developed to measure plutonium-isotopes at CologneAMS and first results for 239,240,242Pu are presented. In addition we report on modifications made on our new TOF device with beam profile capabilities

Ontology-Based News Recommendation

Recommending news items is traditionally done by term-based algorithms like TF-IDF. This paper concentrates on the benefits of recommending news items using a domain ontology instead of using a term-based approach. For this purpose, we propose Athena, which is an extension to the existing Hermes framework. Athena employs a user profile to store terms or concepts found in news items browsed by the user. Based on this information, the framework uses a traditional method based on TF-IDF, and several ontology-based methods to recommend new articles to the user. The paper concludes with the evaluation of the different methods, which show that the ontology-based method, that we propose in this paper, performs better than the content-based approach and the other ontology-based approaches

The first year of operation of CologneAMS; performance and developments

In this contribution we report on the measurements performed so far at CologneAMS and on the quality which has been obtained for the isotopes 10Be, 14C and 26Al. We also describe the procedure developed to measure plutonium-isotopes at CologneAMS and first results for 239,240,242Pu are presented. In addition we report on modifications made on our new TOF device with beam profile capabilities