An in situ instrument for planar O2 optode measurements at benthic interfaces

A new in situ instrument for two‐dimensional mapping of oxygen in coastal sediments is presented. The measuring principle is described, and potential mechanical disturbances, solute and particle smearing associated with the measurements, and calibration routines are evaluated. The first in situ measurements obtained in two different benthic communities are presented. In a shallow photosynthetic sediment (1 m of water depth), an extensive horizontal and temporal variation in the O2 distribution caused by benthic photosynthesis and irrigating fauna was resolved. Repetitive planar optode measurements performed along a transect in central Øresund, Denmark (17 m of water depth) revealed a positive correlation between the apparent O2 penetration depths (OP) measured with a lateral distance <5.0 mm, whereas OP measured with a larger horizontal distance (up to 50 m) were not correlated. Consequently, the OP varied in patches with a characteristic size of 5.0 mm. The instrument described is a powerful new tool for in situ characterization of spatiotemporal variations in O2 distributions within benthic communities. The instrument can be adapted for use at full ocean depths, e.g., on deep‐sea landers or remote operating vehicles

Fiber‐optic oxygen microsensors, a new tool in aquatic biology

A new fiber-optic oxygen microsensor (microoptrode) based on dynamic fluorescence quenching has been developed to measure oxygen gradients in marine sediments and microbial mats. The microoptrodes are fabricated by immobilizing an oxygen-quenchable fluorophore at the tapered tip of an optical fiber. A special optoelectronic system has been designed to measure oxygen with these microoptrodes. It is based on small and cheap optical components and can easily be miniaturized for field applications. In contrast to oxygen microelectrodes, the new oxygen microoptrodes are easy to make, do not consume oxygen, and show no stirring dependence of the signal. In addition, they show excellent long-term stability and storage stability. Hydrogen sulfide, carbon dioxide, and other relevant chemical parameters do not interfere with the measurement. Oxygen profiles in marine sediments obtained from measurements with microoptrodes show good correlation to profiles measured with oxygen microelectrodes

Introduction to the Thematic Section: Expertise and Behaviour: Aspects of Cognitive Translation Studies

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Fast responsive, optical trace level ammonia sensor for environmental monitoring

BACKGROUND: Ammonia is a ubiquitous chemical substance which is created in technical and biological processes and harmful to many different organisms. One specific problem is the toxicity of ammonia in fish at levels of 25 μg/l - a very common issue in today’s aqua culture. In this study we report a development of a fast responsive, optical ammonia sensor for trace concentrations. RESULTS: Different hydrogels have been investigated as host polymers for a pH based sensing mechanism based on fluorescent dyes. A porous hydrophobic fluoropolymer membrane was used as an ion barrier cover layer to achieve a good ammonia permeability. The sensor’s sensitivity towards ammonia as well as crosssensitivity towards pH-value and salinity, and the temperature dependency have been determined. Two different methods to reference fluorescence signals have been employed to eliminate intensity-based measurement drawbacks. CONCLUSION: The presented sensor features high sensitivity and a fast response even at concentrations near 1 ppb. No cross sensitivity towards pH and salinity could be observed and temperature dependency was determined as compensateable. Both referencing approaches prove themselves to be able to provide a simple use of the sensor for in-field applications

Stable optical oxygen sensing materials based on click-coupling of fluorinated platinum(II) and palladium(II) porphyrins—A convenient way to eliminate dye migration and leaching

AbstractNucleophilic substitution of the labile para-fluorine atoms of 2,3,4,5,6-pentafluorophenyl groups enables a click-based covalent linkage of an oxygen indicator (platinum(II) or palladium(II) 5,10,15,20-meso-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin) to the sensor matrix. Copolymers of styrene and pentafluorostyrene are chosen as polymeric materials. Depending on the reaction conditions either soluble sensor materials or cross-linked microparticles are obtained. Additionally, we prepared Ormosil-based sensors with linked indicator, which showed very high sensitivity toward oxygen. The effect of covalent coupling on sensor characteristics, stability and photophysical properties is studied. It is demonstrated that leaching and migration of the dye are eliminated in the new materials but excellent photophysical properties of the indicators are preserved

Synchronous Presentation of a Primary Iliac Lymph Node Plasmacytoma and a Prostate Adenocarcinoma

Synchronous presentation of primary nodal plasmacytoma and prostate cancer is very rare and has not been described in the literature. Here, we report a case of a patient with nodal plasmacytoma whose clinical presentation was suggestive of metastatic prostate cancer in the setting of recently diagnosed prostate cancer. The workup and treatment of both malignancies as well as a possible underlying common pathologic mechanism (IL-6 gene mutation) are discussed

Vom Leben erzählen: Ein Konferenzbericht zu szenischem Lernen und literarischem Verstehen

Schulunterricht als artifizieller Raum ermöglicht Lehr-Lern-Konstellationen, die Laborsituationen ähneln und besondere Schutzräume generieren, zugleich fordert er die Lehrenden heraus, die Lebensweltbezüge der Schülerinnen und Schüler nachvollziehbar und erlebbar in das Geschehen einzubinden und so die Membran zwischen Lebenswirklichkeit und Unterricht für Lernende durchlässig zu gestalten. Wolfgang Klafki profilierte in seinen bildungstheoretischen Studien auch diesen Aspekt unter dem Blickwinkel der zu legitimierenden Auswahl eines Unterrichtsgegenstandes (cf. Klafki 2007: 270ff.). In der Praxis erweist sich diese wichtige und vielseits gestützte Forderung nicht immer und als leicht realisierbar. Mit dem Panel begaben sich Lehrende aus Hochschule und Schule im Rahmen des Deutschen Germanistentages in Bayreuth 2016 gemeinsam und in Anlehnung an Konzepte des ‚artistic research’ bzw. ‚practice as research’ auf die Suche nach Möglichkeiten theatraler Erlebens- und darauf basierender Lehr/-Lernräume im Literaturunterricht. Das Panel richtete sich an theoretisch und praktisch Interessierte, die ihre Auseinandersetzung mit literatur- und theaterdidaktischen und mit theaterpädagogischen Konzepten vor allem im schulischen, aber auch im universitären Literaturunterricht erweitern und vertiefen wollten. Zunächst wurde ein Workshop mit allen Teilnehmenden durchgeführt. Ziel war es, Möglichkeiten der Implementierung alltäglicher Erlebens- und Erfahrenswelten von Schülerinnen und Schülern in den Unterricht vermittels theatraler Lehr-Lernrprozesse praktisch zu erproben und das im Theaterspiel Produzierte wiederum literarischen ..

New highly fluorescent pH indicator for ratiometric RGB imaging of pCO2

A new diketo-pyrrolo-pyrrole (DPP) indicator dye for optical sensing of carbon dioxide is prepared via a simple one step synthesis from commercially available low cost 'Pigment Orange 73'. The pigment is modified via alkylation of one of the lactam nitrogens with a tert-butylbenzyl group. The indicator dye is highly soluble in organic solvents and in polymers and shows pH-dependent absorption (λmax 501 and 572 nm for the protonated and deprotonated forms, respectively) and emission spectra (λmax 524 and 605 nm for the protonated and deprotonated forms, respectively). Both the protonated and the deprotonated forms show high fluorescence quantum yields (Φprot 0.86; Φdeprot 0.66). Hence, colorimetric read-out and ratiometric fluorescence intensity measurements are possible. The emission of the two forms of the indicator excellently matches the response of the green and the red channels of an RGB camera. This enables imaging of carbon dioxide distribution with a simple and low cost optical set-up. The sensor based on the new DPP dye shows very high sensitivity and is particularly promising for monitoring atmospheric levels of carbon dioxide

coupling of a redundant manipulator with a virtual reality environment to enhance human robot cooperation

Abstract The current trend in manufacturing is to obtain a flexible work cell in which human and robot can safely interact and collaborate. Virtual Reality (VR) represents an effective tool capable of simulating such complex systems with a high level of immersion. In order to take advantage of VR technologies to study Human-Robot Cooperation (HRC), a digital model of a redundant manipulator (KUKA LBR iiwa) has been developed starting with kinematic modeling and then coupled with the real robot. This approach allows simulating HRC in several scenarios, to reproduce the safe behavior on the real robot, as well as to train operators