Ten key issues in modern flow chemistry

Ten essentials of synthesis in the flow mode, a new enabling technology in organic chemistry, are highlighted as flashlighted providing an insight into current and future issues and developments in this field. © The Royal Society of Chemistry 2011

"Enabling Technologien" in der organischen Synthese : induktives Heizen und Durchflussreaktionen ; Totalsynthese von Millingtonine A

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The Supermassive Black Hole and Double Nucleus of the Core Elliptical NGC 5419

We obtained adaptive-optics assisted SINFONI observations of the central regions of the giant elliptical galaxy NGC5419 with a spatial resolution of 0.2 arcsec (≈55 pc). NGC5419 has a large depleted stellar core with a radius of 1.58 arcsec (430 pc). HST and SINFONI images show a point source located at the galaxy\u27s photocentre, which is likely associated with the low-luminosity AGN previously detected in NGC5419. Both the HST and SINFONI images also show a second nucleus, off-centred by 0.25 arcsec (≈70 pc). Outside of the central double nucleus, we measure an almost constant velocity dispersion of σ∼350 km/s. In the region where the double nucleus is located, the dispersion rises steeply to a peak value of ∼420 km/s. In addition to the SINFONI data, we also obtained stellar kinematics at larger radii from the South African Large Telescope. While NGC5419 shows low rotation (v\u3c50 km/s), the central regions (inside ∼4rb) clearly rotate in the opposite direction to the galaxy\u27s outer parts. We use orbit-based dynamical models to measure the black hole mass of NGC5419 from the kinematical data outside of the double nuclear structure. The models imply MBH=7.2+2.7−1.9×109 M⊙. The enhanced velocity dispersion in the region of the double nucleus suggests that NGC5419 possibly hosts two supermassive black holes at its centre, separated by only ≈70 pc. Yet our measured MBH is consistent with the black hole mass expected from the size of the galaxy\u27s depleted stellar core. This suggests, that systematic uncertainties in MBH related to the secondary nucleus are small

Mit Spot Farming zur nachhaltigen Intensivierung in der Pflanzenproduktion

Die Landwirtschaft steht vor umwälzenden Veränderungen, die sich aus verschiedenen Herausforderungen ökologischer, ökonomischer und gesellschaftlicher Art ergeben. Mit einer Fortschreibung des aktuellen technischen Entwicklungspfades werden diese zukünftig nicht zu meistern sein. Daraus resultiert die Notwendigkeit, das System Pflanzenbau sowie die zur verfahrenstechnischen Ausgestaltung notwendigen Prozesse grundlegend auf den Prüfstand zu stellen, um zu der geforderten nachhaltigen Intensivierung landwirtschaftlicher Produktion zu kommen. Vor diesem Hintergrund wird das Anforderungsprofil für eine zukünftige Pflanzenproduktion definiert, sich daraus ergebende Herausforderungen formuliert und einzelne Aspekte eines alternativen Produktionssystems betrachtet, wie mit Hilfe moderner Technik neue Wege in der Pflanzenproduktion ermöglicht werden könnten. Dabei liegt der Fokus darauf, zunächst einmal die Grundansprüche der Kulturpflanze sowie weitere übergeordnete Anforderungen und Restriktionen insbesondere im Hinblick auf Strukturen zu befriedigen, um dann darauf aufbauend die erforderliche Verfahrenstechnik für eine teilflächenspezifische Bewirtschaftung abzuleiten. Dies steht im Gegensatz zur bisherigen Praxis, bei der u.a. auch die technische Entwicklung zur uniformen Bewirtschaftung immer größer werdender Schläge geführt hat

Episodic warming of near-bottom waters under the Arctic sea ice on the central Laptev Sea shelf

A multiyear mooring record (2007–2014) and satellite imagery highlight the strong temperature variability and unique hydrographic nature of the Laptev Sea. This Arctic shelf is a key region for river discharge and sea ice formation and export and includes submarine permafrost and methane deposits, which emphasizes the need to understand the thermal variability near the seafloor. Recent years were characterized by early ice retreat and a warming near-shore environment. However, warming was not observed on the deeper shelf until year-round under-ice measurements recorded unprecedented warm near-bottom waters of +0.6°C in winter 2012/2013, just after the Arctic sea ice extent featured a record minimum. In the Laptev Sea, early ice retreat in 2012 combined with Lena River heat and solar radiation produced anomalously warm summer surface waters, which were vertically mixed, trapped in the pycnocline, and subsequently transferred toward the bottom until the water column cooled when brine rejection eroded stratification

Ocean Colour remote sensing in the Southern Laptev Sea: evaluation and applications

Enhanced permafrost warming and increased arctic river discharges have heightened concern about the input of terrigeneous matter into Arctic coastal waters. We used optical operational satellite data from the Ocean Colour sensor MERIS onboard the ENVISAT satellite mission for synoptic monitoring of the pathways of terrigeneous matter in the southern Laptev Sea. MERIS satellite data from 2006 on to 2011 were processed using the Case2Regional Processor, C2R, installed in the open-source software ESA BEAM-VISAT. Since optical remote sensing using Ocean Colour satellite data has seen little application in Siberian Arctic coastal and shelf waters, we assess the applicability of the calculated MERIS parameters with surface water sampling data from the Russian-German ship expeditions LENA2010 and TRANSDRIFT-XVII taking place in August and September 2010 in the southern Laptev Sea. The surface waters of the southern Laptev Sea are characterized by low transparencies, due to turbid river water input, terrestrial input by coastal erosion, resuspension events and, therefore, high background concentrations of Suspended Particulate Matter, SPM, and coloured Dissolved Organic Matter, cDOM. The mapped calculated optical water parameters, such as the first attenuation depth, Z90, the attenuation coefficient, k, and Suspended Particulate Matter, SPM, visualize resuspension events that occur in shallow coastal and shelf waters indicating vertical mixing events. The mapped optical water parameters also visualize that the hydrography of the Laptev Sea is dominated by frontal meanders with amplitudes up to 30 km and eddies and filaments with diameters up to 100 km that prevail throughout the ice-free season. The meander crests, filaments and eddy-like structures that become visible through the mapped MERIS C2R parameters indicate enhanced vertical and horizontal transport energy for the transport of terrigenous and living biological matter in the surface waters during the ice-free season

Diversity of Rhodopirellula and related planctomycetes in a North Sea coastal sediment employing carB as molecular marker.

Rhodopirellula is an abundant marine member of the bacterial phylum Planctomycetes. Cultivation studies revealed the presence of several closely related Rhodopirellula species in European coastal sediments. Because the 16S rRNA gene does not provide the desired taxonomic resolution to differentiate Rhodopirellula species, we performed a comparison of the genomes of nine Rhodopirellula strains and six related planctomycetes and identified carB, coding for the large subunit of carbamoylphosphate synthetase, as a suitable molecular marker. In this study, we investigated the diversity of Rhodopirellula in coastal intertidal surface sediments of Sylt island, North Sea, using the 16S rRNA and carB genes as molecular markers. The carB clone and pyrosequencing libraries revealed the presence of 12 species of Rhodopirellula and of 66 species in closely related undescribed genera, a diversity that was not detected with a 16S rRNA gene library. This study demonstrates that the carB gene is a powerful molecular marker for detecting Rhodopirellula species in the environment and may be used for the taxonomic evaluation of new strains