Editorial: Reconceptualizing public sphere(s) in the digital age? On the role and future of public sphere theory

Theories of the public sphere—or more recently, of plural public spheres—are core elements of communication and media research. A lively and dynamic debate exists about the respective theories, and the approaches employed to do so have diversified in recent years. This special issue of Communication Theory aims to assess the role and future of public sphere(s) theory in digital societies: if, and where, are concepts of the public sphere(s) still useful and needed, which criticisms are (still) valid, which not, which new ones might be necessary, and which concepts need to be developed or elaborated to respond meaningfully to the digital transformation? This editorial introduces the topic of and contributions to the special issue as well as nine theses on the development of public sphere(s) theorizing

Entrapment: an important mechanism to explain the shortwave 3D radiative effect of clouds

Several mechanisms have previously been proposed to explain differences between the shortwave reflectance of realistic cloud scenes computed using the 1D independent column approximation (ICA) and 3D solutions of the radiative transfer equation. When the sun is low in the sky, interception of sunlight by cloud sides tends to increase reflectance relative to ICA estimates that neglect this effect. When the sun is high, 3D radiative transfer tends to make clouds less reflective, which we argue is explained by the mechanism of “entrapment” whereby horizontal transport of radiation beneath a cloud layer increases the chances, relative to the ICA, of light being absorbed by cloud or the surface. It is especially important for multilayered cloud scenes. We describe modifications to the previously described Speedy Algorithm for Radiative Transfer through Cloud Sides (SPARTACUS) to represent different entrapment assumptions, and test their impact on 65 contrasting scenes from a cloud-resolving model. When entrapment is represented explicitly via a calculation of the mean horizontal distance traveled by reflected light, SPARTACUS predicts a mean “3D radiative effect” (the difference in top-of-atmosphere irradiances between 3D and ICA calculations) of 8.1 W m−2 for overhead sun. This is within 2% of broadband Monte Carlo calculations on the same scenes. The importance of entrapment is highlighted by the finding that the extreme assumptions in SPARTACUS of “zero entrapment” and “maximum entrapment” lead to corresponding mean 3D radiative effects of 1.7 and 19.6 W m−2, respectively

Wandel der Kommunikation in der digitalen Gesellschaft: Einführung in das Special Issue zur DACH 21-Dreiländertagung für Kommunikationswissenschaft

Dass die Kommunikationswissenschaft einem kontinuierlichen Wandel unterworfen ist, unterscheidet sie nicht von anderen sozialwissen-schaftlichen Disziplinen. Das liegt nicht zuletzt daran, dass die großen Triebfedern hinter den Wandlungsprozessen überall die gleichen sind. Gesellschaftliche Megatrends wie Globalisierung, Individualisierung und Digitalisierung beeinflussen Politikwissenschaft oder Soziologie genauso wie die Kommunikationswissenschaft. Allerdings – und hier besteht nun doch ein Unterschied – hat insbesondere die Digitalisie-rung für die Kommunikationswissenschaft deutlich unmittelbarere Veränderungen mit sich gebracht als dies in den Nachbardisziplinen der Fall ist. Der Grund dafür ist, dass sie den Gegenstand des Fachs selbst betrifft: Die Digitalisierung der Kommunikation und der Medien führt zu einem Wandel der Art und Weise, wie Informationen in der Gesellschaft hergestellt, vermittelt und genutzt werden. Die daraus resultierenden Entwicklungen, wie z. B. die Möglichkeit der globalen Vernetzung in Sozialen Onlinenetzwerken, über Instant Messenger oder die enorme Ausweitung und Fragmentierung des Medienangebots und seiner Nutzung sind wiederum Phänomene, die aus dem Zusam-menspiel der erwähnten Megatrends resultieren. Kommunikativer Wandel findet allerdings nicht nur langfristig statt, sondern kann sich ebenso kurzfristig, mitunter gar disruptiv vollziehen, wie gerade die Corona-Krise eindrücklich gezeigt hat

Imaging live bee brains using minimally-invasive diagnostic radioentomology

The sensitivity of the honey bee, Apis mellifera L. (Hymeonoptera: Apidae), brain volume and density to behavior (plasticity) makes it a great model for exploring the interactions between experience, behavior, and brain structure. Plasticity in the adult bee brain has been demonstrated in previous experiments. This experiment was conducted to identify the potentials and limitations of MicroCT (micro computed tomograpy) scanning “live” bees as a more comprehensive, non-invasive method for brain morphology and physiology. Bench-top and synchrotron MicroCT were used to scan live bees. For improved tissue differentiation, bees were fed and injected with radiographic contrast. Images of optic lobes, ocelli, antennal lobes, and mushroom bodies were visualized in 2D and 3D rendering modes. Scanning of live bees (for the first time) enabled minimally-invasive imaging of physiological processes such as passage of contrast from gut to haemolymph, and preliminary brain perfusion studies. The use of microCT scanning for studying insects (collectively termed ‘diagnostic radioentomology’, or DR) is increasing. Our results indicate that it is feasible to observe plasticity of the honey bee brain in vivo using diagnostic radioentomology, and that progressive, real-time observations of these changes can be followed in individual live bees. Limitations of live bee scanning, such as movement errors and poor tissue differentiation, were identified; however, there is great potential for in-vivo, non-invasive diagnostic radioentomology imaging of the honey bee for brain morphology and physiology

Mechanically induced cis-to-trans isomerization of carbon–carbon double bonds using atomic force microscopy

Cis-to-trans isomerization of carbon–carbon double bonds can be induced by the application of mechanical force. Using single molecule force spectroscopy by means of atomic force microscopy (AFM) we pulled polymer molecules which contained cis double bonds in the backbone. In the force versus extension profiles of these polymers, a sudden extension increase is observed which is due to the conversion of shorter cis isomers into longer trans isomers. The added length to the polymer results in relaxation in probed force. We find that the isomerization occurs at forces of 800 ± 60 pN, independent of AFM tip and solid substrate chemistries. Investigation of similar polymers which exclusively contained single bonds in the backbone showed no evidence of a similar transition

Gapless Color Superconductivity

We present the dispersion relations for quasiparticle excitations about the color-flavor locked ground state of QCD at high baryon density. In the presence of condensates which pair light and strange quarks there need not be an energy gap in the quasiparticle spectrum. This raises the possibility of gapless color superconductivity, with a Meissner effect but no minimum excitation energy. Analysis within a toy model suggests that gapless color superconductivity may occur only as a metastable phase.Comment: 4 pages, Revtex, eps figures include