1,700 research outputs found
Kūkā-Kūlā Symbolik, Metaphorik und Aneignung eines amerikanischen Softdrinks in der arabischen Literatur
Coca-Cola gilt als stark aufgeladenes Symbol, das für Amerika, Kapitalismus, Konsum oder auch Globalisierung stehen kann. Dementsprechend häufig taucht das Getränk an zentralen Punkten in der arabischen Literatur auf. Diese Arbeit untersucht eine Auswahl an Texten von arabischen Autor:innen und analysiert, wie Coca-Cola in diesen Werken dargestellt wird.
Zu Beginn der Kapitel werden Aspekte einer regionalen Kulturgeschichte Coca-Colas nachgezeichnet. Neben der Untersuchung der symbolischen Dimension wird außerdem der metaphorische Gehalt von Coca-Cola analysiert und eine Auseinandersetzung mit verschiedenen literarischen und kulturellen Aneignungsdynamiken unternommen. Wie diese Arbeit herausarbeitet, wird Coca-Cola regelmäßig und auf unterschiedliche Art und Weise in der Literatur sowie in öffentlichen Diskursen aufgegriffen. Ihre Verwendung ist in Hinblick auf ideologische Verortung, Humor, Aneignungsverhältnisse oder Darstellungen von Gender hoch ambivalent. Durch eine detaillierte literarische Analyse Coca-Colas versucht diese Arbeit, neue Perspektiven und Aspekte arabischer Gegenwartsdiskurse zu erschließen
Biological Activities of Aqueous and Organic Extracts from Tropical Marine Sponges
We report on screening tests of 66 extracts obtained from 35 marine sponge species from the Caribbean Sea (Curaçao) and from eight species from the Great Barrier Reef (Lizard Island). Extracts were prepared in aqueous and organic solvents and were tested for hemolytic, hemagglutinating, antibacterial and anti-acetylcholinesterase (AChE) activities, as well as their ability to inhibit or activate cell protein phosphatase 1 (PP1). The most interesting activities were obtained from extracts of Ircinia felix, Pandaros acanthifolium, Topsentia ophiraphidites, Verongula rigida and Neofibularia nolitangere. Aqueous and organic extracts of I. felix and V. rigida showed strong antibacterial activity. Topsentia aqueous and some organic extracts were strongly hemolytic, as were all organic extracts from I. felix. The strongest hemolytic activity was observed in aqueous extracts from P. acanthifolium. Organic extracts of N. nolitangere and I. felix inhibited PP1. The aqueous extract from Myrmekioderma styx possessed the strongest hemagglutinating activity, whilst AChE inhibiting activity was found only in a few sponges and was generally weak, except in the methanolic extract of T. ophiraphidites
Biological activities of ethanolic extracts from deep-sea antarctic marine sponges
We report on the screening of ethanolic extracts from 33 deep-sea Antarctic marine sponges for different biological activities. We monitored hemolysis, inhibition of acetylcholinesterase, cytotoxicity towards normal and transformed cells and growth inhibition of laboratory, commensal and clinically and ecologically relevant bacteria. The most prominent activities were associated with the extracts from sponges belonging to the genus Latrunculia, which show all of these activities. While most of these activities are associated to already known secondary metabolites, the extremely strong acetylcholinesterase inhibitory potential appears to be related to a compound unknown to date. Extracts from Tetilla leptoderma, Bathydorus cf. spinosus, Xestospongia sp., Rossella sp., Rossella cf. racovitzae and Halichondria osculum were hemolytic, with the last two also showing moderate cytotoxic potential. The antibacterial tests showed significantly greater activities of the extracts of these Antarctic sponges towards ecologically relevant bacteria from sea water and from Arctic ice. This indicates their ecological relevance for inhibition of bacterial microfouling
An Emergent Space for Distributed Data with Hidden Internal Order through Manifold Learning
Manifold-learning techniques are routinely used in mining complex
spatiotemporal data to extract useful, parsimonious data
representations/parametrizations; these are, in turn, useful in nonlinear model
identification tasks. We focus here on the case of time series data that can
ultimately be modelled as a spatially distributed system (e.g. a partial
differential equation, PDE), but where we do not know the space in which this
PDE should be formulated. Hence, even the spatial coordinates for the
distributed system themselves need to be identified - to emerge from - the data
mining process. We will first validate this emergent space reconstruction for
time series sampled without space labels in known PDEs; this brings up the
issue of observability of physical space from temporal observation data, and
the transition from spatially resolved to lumped (order-parameter-based)
representations by tuning the scale of the data mining kernels. We will then
present actual emergent space discovery illustrations. Our illustrative
examples include chimera states (states of coexisting coherent and incoherent
dynamics), and chaotic as well as quasiperiodic spatiotemporal dynamics,
arising in partial differential equations and/or in heterogeneous networks. We
also discuss how data-driven spatial coordinates can be extracted in ways
invariant to the nature of the measuring instrument. Such gauge-invariant data
mining can go beyond the fusion of heterogeneous observations of the same
system, to the possible matching of apparently different systems
Radially polarized passively mode-locked thin-disk laser oscillator emitting sub-picosecond pulses with an average output power exceeding the 100 W level
We report on a high-power passively mode-locked radially polarized Yb:YAG thin-disk oscillator providing 125 W of average output power. To the best of our knowledge, this is the highest average power ever reported from a mode-locked radially polarized oscillator without subsequent amplification stages. Mode-locking was achieved by implementing a SESAM as the cavity end mirror and the radial polarization of the LG*01 mode was obtained by means of a circular Grating Waveguide Output Coupler. The repetition rate was 78 MHz. A pulse duration of 0.97 ps and a spectral bandwidth of 1.4 nm (FWHM) were measured at the maximum output power. This corresponds to a pulse energy of 1.6 μJ and a pulse peak power of 1.45 MW. A high degree of radial polarization of 97.3 ± 1% and an M2-value of 2.16 which is close to the theoretical value for the LG*01 doughnut mode were measured
Learning effective stochastic differential equations from microscopic simulations: combining stochastic numerics and deep learning
We identify effective stochastic differential equations (SDE) for coarse
observables of fine-grained particle- or agent-based simulations; these SDE
then provide coarse surrogate models of the fine scale dynamics. We approximate
the drift and diffusivity functions in these effective SDE through neural
networks, which can be thought of as effective stochastic ResNets. The loss
function is inspired by, and embodies, the structure of established stochastic
numerical integrators (here, Euler-Maruyama and Milstein); our approximations
can thus benefit from error analysis of these underlying numerical schemes.
They also lend themselves naturally to "physics-informed" gray-box
identification when approximate coarse models, such as mean field equations,
are available. Our approach does not require long trajectories, works on
scattered snapshot data, and is designed to naturally handle different time
steps per snapshot. We consider both the case where the coarse collective
observables are known in advance, as well as the case where they must be found
in a data-driven manner.Comment: 19 pages, includes supplemental materia
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