Substantial near-infrared radiation-driven photosynthesis of chlorophyll f-containing cyanobacteria in a natural habitat

© Kühl et al. Far-red absorbing chlorophylls are constitutively present as chlorophyll (Chl) d in the cyanobacterium Acaryochloris marina, or dynamically expressed by synthesis of Chl f, red-shifted phycobiliproteins and minor amounts of Chl d via far-red light photoacclimation in a range of cyanobacteria, which enables them to use near-infrared-radiation (NIR) for oxygenic photosynthesis. While the biochemistry and molecular physiology of Chl f-containing cyanobacteria has been unraveled in culture studies, their ecological significance remains unexplored and no data on their in situ activity exist. With a novel combination of hyperspectral imaging, confocal laser scanning microscopy, and nanoparticle-based O2 imaging, we demonstrate substantial NIR-driven oxygenic photosynthesis by endolithic, Chl f-containing cyanobacteria within natural beachrock biofilms that are widespread on (sub)tropical coastlines. This indicates an important role of NIR-driven oxygenic photosynthesis in primary production of endolithic and other shaded habitats

Mapping the absence : A theological critique of posthumanist influences in marketing and consumer research

In this study, we critically examine the ongoing adoption of various posthumanist influences into the fields of marketing and consumer research from a theological perspective. By conducting a theological-historical assessment, we propose that it is not posthuman notions of human/technology relations, nor their broader context in the emerging non-representational paradigms, that mark radically new disruptions in the continuing restructuring of the disciplines of marketing and consumer research. Instead, we argue that what is taking place is an implicit adherence to a contemporary form of age-old Christian dogma. As a radical conjecture, we thus propose that an identification of certain similarities between Christian dogma and the grounds for various posthumanist frameworks suggest that posthuman thought may well herald the global dissemination of a far more elusive, authoritarian, and hegemonic system than that which posthumanists typically claim to have abandoned. Consequently, we elaborate on implications to developments in marketing thought.Peer reviewe

Evaluation of Ebselen-azadioxatriangulenium as redox-sensitive fluorescent intracellular probe and as indicator within a planar redox optode

Redox homeostasis is essential for cellular survival and is therefore tightly regulated. Visualizing changes in the local redox state is essential for detecting oxidative stress, especially with the help of red, long emission lifetime probes. We synthesized a new reversible, redox-sensitive fluorescent probe, ebselen-azadioxatriangulenium (Ebselen-ADOTA), and characterized its potential use for intra- and extracellular redox sensing. The probe consists of a photostable triangulenium-based fluorophore (emission maximum at 564 nm) modulated by a redox-active ebselen motif. The reduced form only shows around 1/10 of the emission intensity of the oxidized form. The Ebselen-ADOTA probe exhibited reversible oxidation and reduction in solution under extracellular conditions. In addition, Ebselen-ADOTA can visualize an increase in oxidative stress within anaerobic bacteria when exposing them to air, the probe did not readily respond to changes in the redox environment inside mammalian cells, probably due to unfavorable localization, aggregation or binding to cysteine containing proteins. When incorporated inside a polymer matrix (hydrogel D4 mixed with poly(acrylic acid)), the probe showed a rapid and fully reversible response to redox changes, thus enabling the preparation of a redox-sensitive optode

The Array Control and Data Acquisition System of the Cherenkov Telescope Array

International audienceThe Cherenkov Telescope Array (CTA) project is the initiative to build the next-generation gamma-ray observatory. With more than 100 telescopes planned to be deployed at two sites, CTA is one of the largest astronomical facilities under construction. The Array Control and Data Acquisition (ACADA) system will be the central element of on-site CTA Observatory operations. The mission of the ACADA system is to manage and optimize the telescope array operations at each of the CTA sites. To that end, ACADA will provide all necessary means for the efficient execution of observations, and for the handling of the several Gb/s of data generated by each individual CTA telescope. The ACADA system will contain a real-time analysis pipeline, dedicated to the automatic generation of science alert candidates as data are being acquired. These science alerts, together with external alerts arriving from other scientific installations, will permit ACADA to modify ongoing observations at sub-minute timescales in order to study high-impact scientific transient phenomena. This contribution describes the challenges, architecture, design principles, and development status of the ACADA system