Pathos und Passion: Ikonen des Fotojournalismus in bildwissenschaftlicher Tradition

Die Medienikone, als Bildform der Moderne und Synthese von Tradition und Innovation, konnte erst im Zusammenspiel mit den Massenmedien entstehen. Einzelnen Bildern, meist fotografischer Natur, gelingt es dabei aus der Masse an täglich produzierten Bildern hervorzustechen, die Aufmerksamkeit der Medien und des Publikums gleichermaßen zu fesseln und durch massenhafte Verbreitung, Reproduktion und Reinszenierung den Status einer Medienikone zu erlangen. Dabei befindet sich die Medienikone bis heute im ständigen Wandel: Technische Neuerungen, Digitalisierung, Virtualisierung und veränderte Bildwahrnehmung beeinflussen den Ikonisierungsprozess. Trotz dieser Veränderungen orientieren sich ihre gestalterischen Mittel oftmal ans althergebrachten Mustern und Motiven, die einen langen bildwissenschaftlichen Vorlauf besitzen. Speziell Ikonen des Fotojournalismus machen sich diese Rückbezuge zu vertrauten Darstellungsformen zu nutzen. Diese Anschlussfähigkeit ist oftmals sogar der Schlüssel zu ihrem Erfolg. Anhand von drei Ikonen des Fotojournalismus wird in diesem Beitrag die Konnektivität moderner Medienikonen zu etablierten kunsthistorischen Darstellungsformen beispielhaft nachvollzogen und ihre Bedeutung für den Ikonisierungsprozess herausgearbeitet.The media icon, as an image form of modernity and synthesis of tradition and innovation, could only emerge in the interaction with the mass media. Individual images, mostly of a photographic nature, succeed in standing out from the mass of images produced daily, capturing the attention of the media and the public alike, and attaining the status of a media icon through mass distribution, reproduction, and re-staging. At the same time, the media icon is still in a constant state of flux today: technical innovations, digitization, virtualization, and changes in image perception influence the iconization process. Despite these changes, their creative means are often based on traditional patterns and motifs that have a long history in image science. Icons of photojournalism in particular make use of these references back to familiar forms of representation. This connectivity is often the key to their success. Using three icons of photojournalism as examples, this article traces the connectivity of modern media icons to established art-historical forms of representation and elaborates their significance for the iconization process

Towards the resolution of the e+e- --> Nbar N puzzle

We discuss the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to the threshold, in particular the fact that sigma(e+e- --> nbar n) is somewhat greater than sigma(e+e- --> pbar p). We discuss an interpretation in terms of a two-step process, via an intermediate coherent isovector state serving as an intermediary between e+e- and the baryon-antibaryon system. We provide evidence that the isovector channel dominates both e+e- --> pions and from Nbar N annihilation at rest, and show that the observed ratio of sigma(e+e- --> nbar n)/sigma(e+e- --> pbar p) can be understood quantitatively in this picture.Comment: Invited talk at the Int. Workshop "Light-cone Physics: Particles and Strings", Trento, Sept. 3-11, 200

Baryon-antibaryon annihilation in the Skyrme model

The dynamics of Skyrmion-anti-Skyrmion annihilations in 3+1 dimensions is examined by the numerical integration of the classical Hamilton equations of motion. The baryon number is found to disappear extremely rapidly, close to the causal limit, while the energy distribution still remains concentrated in the annihilation region. The emission of pion waves emitted by the annihilation process is investigated

A Non-Perturbative Treatment of the Pion in the Linear Sigma-Model

Using a non-perturbative method based on the selfconsistent Quasi-particle Random-Phase Approximation (QRPA) we describe the properties of the pion in the linear $\sigma$-model. It is found that the pion is massless in the chiral limit, both at zero- and finite temperature, in accordance with Goldstone's theorem.Comment: To appear in Nucl.Phys. A, 16 pages, 2 Postscript figure

Mouse model for acute Epstein-Barr virus infection

Epstein-Barr Virus (EBV) infects human B cells and drives them into continuous proliferation. Two key viral factors in this process are the latent membrane proteins LMP1 and LMP2A, which mimic constitutively activated CD40 receptor and B-cell receptor signaling, respectively. EBV-infected B cells elicit a powerful T-cell response that clears the infected B cells and leads to life-long immunity. Insufficient immune surveillance of EBV-infected B cells causes life-threatening lymphoproliferative disorders, including mostly germinal center (GC)-derived B-cell lymphomas. We have modeled acute EBV infection of naive and GC B cells in mice through timed expression of LMP1 and LMP2A. Although lethal when induced in all B cells, induction of LMP1 and LMP2A in just a small fraction of naive B cells initiated a phase of rapid B-cell expansion followed by a proliferative T-cell response, clearing the LMP-expressing B cells. Interfering with T-cell activity prevented clearance of LMP-expressing B cells. This was also true for perforin deficiency, which in the human causes a life-threatening EBV-related immunoproliferative syndrome. LMP expression in GC B cells impeded the GC reaction but, upon loss of T-cell surveillance, led to fatal B-cell expansion. Thus, timed expression of LMP1 together with LMP2A in subsets of mouse B cells allows one to study major clinically relevant features of human EBV infection in vivo, opening the way to new therapeutic approaches

Level Density of a Bose Gas and Extreme Value Statistics

We establish a connection between the level density of a gas of non-interacting bosons and the theory of extreme value statistics. Depending on the exponent that characterizes the growth of the underlying single-particle spectrum, we show that at a given excitation energy the limiting distribution function for the number of excited particles follows the three universal distribution laws of extreme value statistics, namely Gumbel, Weibull and Fr\'echet. Implications of this result, as well as general properties of the level density at different energies, are discussed.Comment: 4 pages, no figure

Level density of a Fermi gas: average growth and fluctuations

We compute the level density of a two--component Fermi gas as a function of the number of particles, angular momentum and excitation energy. The result includes smooth low--energy corrections to the leading Bethe term (connected to a generalization of the partition problem and Hardy--Ramanujan formula) plus oscillatory corrections that describe shell effects. When applied to nuclear level densities, the theory provides a unified formulation valid from low--lying states up to levels entering the continuum. The comparison with experimental data from neutron resonances gives excellent results.Comment: 4 pages, 1 figur

The dynamics of an omnidirectional pendulum harvester

The pendulum applied to the field of mechanical energy harvesting has been studied extensively in the past. However, systems examined to date have largely comprised simple pendulums limited to planar motion and to correspondingly limited degrees of excitational freedom. In order to remove these limitations and thus cover a broader range of use, this paper examines the dynamics of a spherical pendulum with translational support excitation in three directions that operate under generic forcing conditions. This system can be modelled by two generalised coordinates. The main aim of this work is to propose an optimisation procedure to select the ideal parameters of the pendulum for an experimental programme intended to lead to an optimised pre-prototype. In addition, an investigation of the power take-off and its effect on the dynamics of the pendulum is presented with the help of Bifurcation diagrams and Poincaré sections

Dynamics of an omnidirectional pendulum energy harvester : a comparative analysis between numerical and experimental results

The spherical pendulum is a mathematically interesting model that has been studied extensively in the past. In the field of energy harvesting however, the pendulum energy harvesters are generally confined to planar motions. This minimisation of the available degrees of freedom potentially limits the areas of application of the energy harvester, and certainly its overall capability. In this work an omnidirectional pendulum energy harvester is proposed in the form of a two degree of freedom system which has the potential to harvest energy from motions along the three axes of translation and from the three corresponding rotations about those axes. The dynamics of such an energy harvester are examined experimentally for different power take-off modes and are subsequently compared to numerical predictions from an analytical model. An optimal operational point is proposed for the harvester and it is shown how an up-sweep and down-sweep of the excitation frequency can significantly broaden the operational range of the energy harvester by up to 130%