The EU in Times of COVID-19: Together into a Future Based on (More) Solidarity?

The outbreak of the COVID-19-pandemic in spring 2020 put solidarity within the European Union to the test and called for far-reaching responses by all member states to mitigate the pandemic’s effects. But how does this crisis affect public support for transnational solidarity in the European Union? Are EU citizens willing to collectively overcome a financial crisis caused by the COVID-19-pandemic? And what is the public opinion on the establishment of a fictional EU-wide fund to mitigate future crises? Those questions have been addressed by a multi-country survey run by the ‘Solikris’-project. A resulting analysis in the project’s Policy Brief #5 shows that particularly the macroeconomic differences between countries correlate with attitudes towards solidarity policies and that transnational solidarity is higher in situations of acute crisis.Der Ausbruch der COVID-19-Pandemie im Frühjahr 2020 stellte die Solidarität innerhalb der Europäischen Union auf die Probe und erforderte weitreichende Reaktionen aller Mitgliedsstaaten, um die Auswirkungen der Pandemie zu mildern. Doch wie wirkt sich diese Krise auf die öffentliche Unterstützung für transnationale Solidarität in der Europäischen Union aus? Sind die EU-Bürger*innen bereit, eine durch die COVID-19-Pandemie verursachte Finanzkrise kollektiv zu bewältigen? Und wie ist die öffentliche Meinung zur Einrichtung eines fiktiven EU-weiten Fonds zur Abfederung zukünftiger Krisen? Diese Fragen wurden in einer länderübergreifenden Umfrage des ‘Solikris’-Projekts untersucht. Eine daraus resultierende Analyse im Policy Brief #5 des Projekts zeigt, dass insbesondere die makroökonomischen Unterschiede zwischen den Ländern mit den Einstellungen zur Solidaritätspolitik korrelieren und dass die transnationale Solidarität in akuten Krisensituationen höher is

Density dependence of the Ionization Avalanche in ultracold Rydberg gases

We report on the behaviour of the ionization avalanche in an ensemble of ultracold 87Rb atoms coupled to a high lying Rydberg state and investigate extensions to the current model by including the effects of three-body recombination and plasma expansion. To separate the two effects we study the time dependence of the plasma formation at various densities as well as for different nS and nD states. At medium densities and low n we observe the onset of the avalanche as has been reported in other experiments, as well as a subsequent turn-off of the avalanche for longer excitation times, which we associate with plasma expansion. At higher densities and for higher lying Rydberg states we observe a disappearance of the avalanche signature, which we attribute to three-body recombination.Comment: 5 pages, 4 figure

The Integrated Polarization of Spiral Galaxy Disks

We present integrated polarization properties of nearby spiral galaxies at 4.8 GHz, and models for the integrated polarization of spiral galaxy disks as a function of inclination. Spiral galaxies in our sample have observed integrated fractional polarization in the range < 1% to 17.6%. At inclinations less than 50 degrees, the fractional polarization depends mostly on the ratio of random to regular magnetic field strength. At higher inclinations, Faraday depolarization associated with the regular magnetic field becomes more important. The observed degree of polarization is lower (<4%) for more luminous galaxies, in particular those with L_{4.8} > 2 x 10^{21} W/Hz. The polarization angle of the integrated emission is aligned with the apparent minor axis of the disk for galaxies without a bar. In our axially symmetric models, the polarization angle of the integrated emission is independent of wavelength. Simulated distributions of fractional polarization for randomly oriented spiral galaxies at 4.8 GHz and 1.4 GHz are presented. We conclude that polarization measurements, e.g. with the SKA, of unresolved spiral galaxies allow statistical studies of the magnetic field in disk galaxies using large samples in the local universe and at high redshift. As these galaxies behave as idealized background sources without internal Faraday rotation, they can be used to detect large-scale magnetic fields in the intergalactic medium.Comment: 13 pages, 6 figures; Accepted for publication in The Astrophysical Journa

Chandra Observation of the Edge-on Galaxy NGC 3556 (M 108): Violent Galactic Disk-halo Interaction Revealed

We present a 60 ks Chandra ACIS-S observation of the isolated edge-on spiral NGC 3556, together with a multiwavelength analysis of various discrete X-ray sources and diffuse X-ray features. Among 33 discrete X-ray sources detected within the I_B = 25 mag per square arcsec isophote ellipse of the galaxy, we identify a candidate for the galactic nucleus, an ultraluminous X-ray source that might be an accreting intermediate-mass black hole, a possible X-ray binary with a radio counterpart, and two radio-bright giant HII regions. We detect large amounts of extraplanar diffuse X-ray emission, which extends about 10 kpc radially in the disk and >~ 4 kpc away from the galactic plane. The diffuse X-ray emission exhibits significant substructures, possibly representing various blown-out superbubbles or chimneys of hot gas heated in massive star forming regions. This X-ray-emitting gas has temperatures in the range of ~ 2-7 x 10^6 K and has a total cooling rate of ~ 2 x 10^40 erg/s. The energy can be easily supplied by supernova blast-waves in the galaxy. These results demonstrate NGC 3556 as being a galaxy undergoing vigorous disk-halo interaction. The halo in NGC 3556 is considerably less extended, however, than that of NGC 4631, in spite of many similarities between the two galaxies. This may be due to the fact that NGC 3556 is isolated whereas NGC 4631 is interacting. Thus NGC 3556 presents a more pristine environment for studying the disk-halo interaction.Comment: 30 pages, 12 figures. To appear in ApJ. Please see http://www.astro.umass.edu/~wqd/papers/n3556/n3556.pdf for a high resolution versio

Coherence Properties of Guided-Atom Interferometers

We present a detailed investigation of the coherence properties of beam splitters and Mach-Zehnder interferometers for guided atoms. It is demonstrated that such a setup permits coherent wave packet splitting and leads to the appearance of interference fringes. We study single-mode and thermal input states and show that even for thermal input states interference fringes can be clearly observed, thus demonstrating the multimode operation and the robustness of the interferometer.Comment: 4 pages, 4 figure

Design and Synthesis of a Potential Chemotherapeutic Agent Using Goniothalamin as a Natural Product Template

Goniothalamin, a natural product extracted from the tree bark of the Goniothalamus genus, has been shown to induce apoptosis in cancer cells. It is hypothesized that goniothalamin\u27s biological activity is due to its ability to react with thiols. Goniothalamin has been shown to decrease levels of glutathione, a natural antioxidant, found in cancer cells. This causes a redox imbalance, which ultimately leads to cell death. Thiol-reactive compounds, like goniothalamin, have also been shown to inhibit nuclear factor-κB (NF-κB). NF-κB is a transcription factor that has been implicated in unregulated cell growth. Through a nine step sequence, a novle analogue of goniothalamin has been prepared that replaces the lactone core of the nature product with a cyclohexenone. The synthetic sequence features a unique enol ether protection of beta-diketone which allows facile preparation of the desired analogue. It is anticipated that the novel goniothalamin derivative will demonstrate increaed cytotoxicity against cancer cells

Towards a guided atom interferometer based on a superconducting atom chip

We evaluate the realization of a novel geometry of a guided atom interferometer based on a high temperature superconducting microstructure. The interferometer type structure is obtained with a guiding potential realized by two current carrying superconducting wires in combination with a closed superconducting loop sustaining a persistent current. We present the layout and realization of our superconducting atom chip. By employing simulations we discuss the critical parameters of the interferometer guide in particular near the splitting regions of the matter waves. Based on measurements of the relevant chip properties we discuss the application of a compact and reliable on-chip atom interferometer.Comment: 14 pages, 7 figures, accepted for New Journal of Physic

Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Polarization

We present a full-sky model of polarized Galactic microwave emission based on three years of observations by the Wilkinson Microwave Anisotropy Probe (WMAP) at frequencies from 23 to 94 GHz. The model compares maps of the Stokes Q and U components from each of the 5 WMAP frequency bands in order to separate synchrotron from dust emission, taking into account the spatial and frequency dependence of the synchrotron and dust components. This simple two-component model of the interstellar medium accounts for at least 97% of the polarized emission in the WMAP maps of the microwave sky. Synchrotron emission dominates the polarized foregrounds at frequencies below 50 GHz, and is comparable to the dust contribution at 65 GHz. The spectral index of the synchrotron component, derived solely from polarization data, is -3.2 averaged over the full sky, with a modestly flatter index on the Galactic plane. The synchrotron emission has mean polarization fraction 2--4% in the Galactic plane and rising to over 20% at high latitude, with prominent features such as the North Galactic Spur more polarized than the diffuse component. Thermal dust emission has polarization fraction 1% near the Galactic center, rising to 6% at the anti-center. Diffuse emission from high-latitude dust is also polarized with mean fractional polarization 0.036 +/- 0.011.Comment: 9 pages with 8 figures. For higher quality figures, see the version posted at http://lambda.gsfc.nasa.gov/product/map/dr2/map_bibliography.cf