Spectroscopic UV/vis limb measurements from aboard the NASA Global Hawk: Implications for the photochemistry and budget of bromine in the tropical tropopause layer

The present thesis reports on the world's first measurements of the second most important ozone-depleting halogen bromine at the entrance to the stratosphere (14 - 18.5 km, theta = 330 - 400 K) over the East and Central Pacific in late winter 2013. The measurements were performed within the NASA-ATTREX project from aboard the unmanned aerial vehicle Global Hawk. For the interpretation of the remote-sensing DOAS measurements of O3, NO2 and BrO, use of complementary measurements of brominated source gases (SGs) and dynamical tracers (e.g. CH3Br, halons, very short-lived species (VSLS), CH4) and model simulations of the chemical transport model (CTM) SLIMCAT/TOMCAT, is made. The agreement of measured and modelled CH4, O3, and NO2 shows that the major dynamicaland photochemical processes are represented well in the CTM. Considering surface concentrations of the brominated organic SGs of in total 20.5 ppt, the measured BrO mixing ratios (0.5 - 9.0 ppt) are well explained. An exception are regions where the contribution of the short-lived CH2Br2 or the partitioning of BrONO2 plays an important role. The present observations confirm previous findings on the formation of BrONO2 of our workgroup. Depending on the flight, a total bromine budget (Bry) in the tropical tropopause layer (TTL) of 20.3 ppt to 22.3 ppt is inferred. For each fligh the contribution to total bromine of the long-lived brominated SGs stays constant (CH3Br + halons = 14.6 ppt), while the amount of VSLS and inorganic bromine varies between 5.7 ppt and 7.7 ppt. Thus, the present observations set a tighter constraint on the role of bromine for ozone depletion in the TTL than previous studies

Productivity and life cycles of plankton and nekton in the coastal upwelling area of the Benguela shelf : trophic and physical-chemical control mechanisms ; cruise No. MSM07, 11.02.2008 – 15.04.2008

Fahrtabschnitt MSM 07/1 Transit Rostock - Las Palmas. Fahrtabschnitt MSM 07/2a Auf der Transitreise zwischen Las Palmas de Canaria und Walfischbai wird die Wirkung unterschiedlicher biogeochemischer Grundbedingungen auf Produktions/ Abbau-Gleichgewichte in den primären Ebenen des pelagischen Ökosystems untersucht. Auf einem Schnitt über den Äquator stehen die physikalischdynamischen Prozesse im äquatorialen Stromsystem im Vordergrund. Vor dem Kunene-Fluß sollen die benthischen Besiedlungsmuster mit funktionellen Mustern der Austauschdynamik zwischen Sediment und Wasser in Beziehung gesetzt werden. Fahrtabschnitt MSM 07/2b Die deutsche IMBER-Initiative (GIMBER) untersucht die Wechselwirkungen zwischen biologischen Ökosystemkomponenten, biogeochemischen und physikalischen Prozessen und menschlichen Einflüssen auf marine Ökosysteme. Im Benguela- Auftrieb wird untersucht, wie Effekte struktureller Unterschiede der primärproduzierenden Gemeinschaft (Flagellaten-/Diatomeen-plankton) weiter in das Nahrungsnetz propagieren und die trophischen Beziehungen in höheren Ebenen beeinflussen. Für wichtige pelagische Gruppen wie Copepoden, Euphausiaceen, gelatinöses Zooplankton, Fischlarven und mesopelagisches Nekton werden mit modernsten Methoden Daten zu Abundanz, Vertikalverteilung, Nahrungsspektren, Trophodynamik und physiologischen Raten erhoben. Sie bilden die Grundlage für trophische und biogeochemische Modelle im Rahmen des geplanten GIMBERProgramms und sollen Aufschluss über zu erwartende Folgen eines Regimewechsels in heimischen Gewässern geben. Synopsis Fahrtabschnitt MSM 07/3 Der dritte Fahrtabschnitt ist besonders auf die Durchführung von physiologischen Experimenten an Bord des Schiffes zugeschnitten. Aufbauend auf die großflächigere hydrographische und planktologische Aufnahme im Untersuchungsgebiet während des vorangegangenen Fahrtabschnittes sowie aktuellen Satellitenbildern zur Temperatur- und Chlorophyll-a Verteilung werden Organismen für die Experimente gefangen. Dabei werden in aussichtsreichen Gebieten kurze, küstennormale Schnitte bearbeitet, auf denen verschiedene Netze mit unterschiedlichsten Maschenweiten zum Einsatz kommen. Verschiedene Gruppen von Plankton werden untersucht: Copepoden, Euphausiaceen und Fischlarven stehen im Mittelpunkt. Über die in-situ Verteilung der Organismen werden Untersuchungen mit einem undulierenden Videoplanktonrekorder (OKI) Auskunft geben. Zum Abschluss der Stationsarbeiten wird ein Süd-Nord-Schnitt auf 11°30´O, der sich von 19 bis 14° S erstrecken soll. Die lange Überfahrt aus dem Untersuchungsgebiet nach Mindelo, Kapverden, wird für intensive physiologische Untersuchungen an Bord genutzt werden.Leg MSM 07/1 Transit Rostock - Las Palmas. Leg MSM 07/2a On transit between Las Palmas de Canaria and Walvis Bay the effect of different biogeochecmical base settings on the production/decomposition-equilibria on the primary levels of the ecosystem will be studied. On a transect across the equator the physical-dynamic processes in the equatorial current system are on the focus. Off the Kunene river mouth benthic colonization patterns are compared with the distribution of functional properties , in this case the exchange dynamics between sediment and water. Leg MSM 07/2b The German IMBER-initiative (GIMBER) concentrates on the study of interactions between biological system components, biogeochemical and physical processes and human impacts on marine ecosystems. In the region of the Benguela upwelling it will be studied how effects of structural differences in the communities of primary producers (flagellates vs. diatoms) will further progagate through the foodweb and regulate throphic interactions on higher levels. Data of abundance, vertical distribution, food spectra, trophodynamics and physiological rates will be recorded for important pelagic target groups like copepods, euphhausids, gelatinous zooplankton, fish larvae and mesopelagic nekton employing state of the art methodology. These data serve as a base for trophic and biogeochemical modelling in the frame of the planned GIMBERprogramme and are supposed to provide information on the expected results of a regime shift in domestic waters. Leg MSM 07/3 The third cruise leg is dedicated especially to the implementation of physiological experiments on board of the ship. Based on the more large scale hydrographical and planktological station work of the cruise legs 2a and 2b as well as on realtime satellite images of sea surface temperature and chlorophyll- a distribution, live organisms in good condition will be caught for the experiments on board. In selected areas, short transects perpendicular to the coast will be performed, and a number of different nets with different mesh sizes will be used. Different taxonomical groups of plankton will be investigated: copepods, euphausiids, and fish larvae are in the focus of these works. An undulating video plankton recorder (OKI) will be used to investigate the in-situ small-scale distribution of planktonic organisms. In continuation of the hydrographical and planktological work done in the area since many years, a South-North transect at 11°3E is planned at the end of the station work, reaching from 19 to 14°S. The passage from the investigation area to Mindelo, Cape Verde, will be used to continue the physiological experiments as long as possible

Defining properties of neural crest-derived progenitor cells from the apex of human developing tooth

The connective tissue of the human tooth arises from cells that are derived from the cranial neural crest and, thus, are termed as "ectomesenchymal cells." Here, cells being located in a pad-like tissue adjacent to the apex of the developing tooth, which we designated the third molar pad, were separated by the microexplant technique. When outgrowing from the explant, dental neural crest-derived progenitor cells (dNC-PCs) adhered to plastic, proliferated steadily, and displayed a fibroblast-like morphology. At the mRNA level, dNC-PCs expressed neural crest marker genes like Sox9, Snail1, Snail2, Twist1, Msx2, and Dlx6. Cytofluorometric analysis indicated that cells were positive for CD49d (alpha4 integrin), CD56 (NCAM), and PDGFRalpha, while negative for CD31, CD34, CD45, and STRO-1. dNC-PCs could be differentiated into neurogenic, chondrogenic, and osteogenic lineages and were shown to produce bone matrix in athymic mice. These results demonstrate that human third molar pad possesses neural crest-derived cells that represent multipotent stem/progenitor cells. As a rather large amount of dNC-PCs could be obtained from each single third molar, cells may be used to regenerate a wide range of tissues within the craniofacial region of humans

Characterization of the stability radius via bifurcation techniques

Robustness of stability of linear time-invariant systems using the relationship between the structured compex stability radius and a prametrized algebraic Riccato equation is analysed. Our approach is based on the observation that the algebraic Riccati equation can bie viewed as a bifurcation problem. It ist proves that the stability radius ist, under certain assumptions, associated with a turning point of the bifurcation problem given by the parametrized algebraic Riccati equation. As a byproduct, the stability radius can be computed via path following. Some numerical examples are presented

Baculovirus-Mediated Expression of Human 65 kDa and 67 kDa Glutamic Acid Decarboxylases in SF9 Insect Cells and Their Relevance in Diagnosis of Insulin-Dependent Diabetes Mellitus

cDNAs coding for the full-length human 65 and 67 kDa glutamic acid decarboxylases (GAD65 and GAD67) were amplified from pancreas and hippocampus cDNA libraries by polymerase chain reaction, respectively. Both cDNAs were inserted into a baculovirus vector which mediated highly efficient expression of the human GAD65 and GAD67 with histidine-hexapeptides as affinity ligands at their C-termini in Spodoptera frugiperda (Sf9) cells. The recombinant GAD proteins were purified to homogeneity by affinity chromatography using a metal-chelating matrix. The infected Sf9 insect cells expressed the recombinant human GAD65 and GAD67 with natural-like conformations, as confirmed by measurement of their enzyme activities as well as their fully restored autoantigenicities. Immunoprecipitation of metabolically labeled infected Sf9 cells demonstrated the autoantigenic potential of the recombinant GAD proteins. The practicability of using recombinant GAD65 and GAD67 derived from the baculovirus expression system for the development of an immunoassay for the diagnosis of insulin-dependent diabetes mellitus is discussed

CAR FOLLOWING MODELS FOR PHENOMENONS ON THE HIGHWAY

Car following models are used to describe the behavior of a number of cars on the road dependent on the distance to the car in front. We introduce a system of ordinary differential equations and perform a theoretical and numerical analysis in order to find solutions that reflect various traffic situations. We present three different variations of the model motivated by reality

Les reseaux hvdc multi-terminaux: des defies multipes en genie electrique high voltage direct current grid multiterminals: many challenges in electrical engineering

Electrical installation using high voltage need to be improve to make the exchanges of power under the sea with security and to connect the offshore sources. Alterative grid show limits in those applications. High voltage direct current (HVDC) installation can be a solution to those cases, if some technological and scientist problem are solved. Challenge are in every level of the electrical engineering work, in the whole system, with the material used, and the way their used. This article introduce the main challenges in the domain of electrical engineering to solve in case of the exploitation of a HVDC grid

Pathogenic Fungi Regulate Immunity by Inducing Neutrophilic Myeloid-Derived Suppressor Cells

Peer reviewedPublisher PD