75 research outputs found

    Biology and biogeochemistry of the eastern mediterranean sea : research vessel Meteor, cruise No. M71 ; 11. Dez. 2006 - 04. Feb. 2007

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    Die METEOR-Fahrt 71 umfasst 3 biologisch und biogeochemisch orientierte Fahrtabschnitte mit insgesamt 50 Schiffstagen im östlichen Mittelmeer und hat folgende Ziele: Der Abschnitt METEOR 71-1 dient der physikalischen, biogeochemischen und biologischen Probengewinnung im Bereich der Anaximander Mountains. Es gibt nur einige wenige Seeberge im östlichen Mittelmeeres, die weitgehend isoliert vom ĂŒbrigen Ozean sind und in einer Region liegen, die sich durch ein im Vergleich zum Weltozean sehr warmes Tiefenwasser von rund 14 °C auszeichnet. Hauptziel der Untersuchungen an einem Gipfel der Anaximander Mountains ist die Beantwortung der Frage, ob sich ein Seeberg-Ökosystem in einer oligotrophen Region mit warmen Tiefenwasser in Bezug auf seinen Einfluß auf das umgebende Strömungs- und NĂ€hrstoffregime, die ProduktivitĂ€t und Verteilung der Nahrungsketten, sowie in Bezug auf die GrĂ¶ĂŸe der „Sphere of interference“, das heißt dem Einflußbereich des Seamounts auf den umgebenden Wasserkörper, Ă€hnlich verhĂ€lt wie entsprechende Erhebungen im Nordostatlantik. Die Expedition METEOR 71-2 beschĂ€ftigt sich mit der BiodiversitĂ€t in der Tiefsee des östlichen Mittelmeeres und ihren Steuerungsfaktoren (Tiefe, KĂŒstenabstand, NahrungsverfĂŒgbarkeit). Zum einen geht es um eine möglichst vollstĂ€ndige Erfassung der Artenzusammensetzung in zwei Referenzregionen durch Vielfachbeprobung an der selben Stelle, zum anderen um die Unterschiede des Arteninventars und des Artenreichtums in AbhĂ€ngigkeit von der Tiefe und vom KĂŒstenabstand. Die Arbeitsgebiete von jeweils 17 sm x 5 sm sind das Ierapetra-Becken sĂŒdlich Kreta. (> 4000m Tiefe) und ein Gebiet der gleichen GrĂ¶ĂŸe weiter sĂŒdlich (2800 m Tiefe doppelter Abstand zur KĂŒste).Die Untersuchungen berĂŒcksichtigen alle Grössenklassen des Benthos (Mega-, Macro-, Meiound Nanofauna), um Gemeinsamkeiten und Unterschiede in der AbhĂ€ngigkeit der BiodiversitĂ€t von Ökofaktoren zu erkennen. Damit sollen die Struktur und die Funktion der Lebensgemeinschaften am Ă€ußerst oligotrophen Tiefseeboden des levantinischen Beckens besser und detaillierter verstanden werden. Arbeiten der Expedition METEOR 71-3 zielen auf die KlĂ€rung der Frage, ob im heutigen Mittelmeer Phosphatverlust und unvollstĂ€ndige Nitratnutzung, oder Stickstoff-Fixierung im ultraoligotrophen östlichen Mittelmeer fĂŒr isotopisch abgereicherte d15N Signaturen von Sedimenten und Schwebstoffen verantwortlich sind. Ein Nebenziel ist die Gewinnung zusĂ€tzlicher OberflĂ€chensedimente, um die Datenbasis fĂŒr Eichungen des UKÂŽ37-Index und AbschĂ€tzung der NĂ€hrstoffakkumulationsraten in Sedimenten im Mittelmeers zu verbessern. Dazu werden auf Schnitten durch das östliche Mittelmeer NĂ€hrstoffprofile beprobt, Proben fĂŒr Messungen der 15N/14N-VerhĂ€ltnisse in Nitrat, gelöstem organischem Stickstoff, in Sinkstoffen und OberflĂ€chensedimenten gewonnen, Untersuchungen des Phytoplanktons sowie Messungen von N2-Fixierungsraten durchgefĂŒhrt. Weiter werden molekulare Techniken eingesetzt, um das Vorhandensein und die Transkription der nifH-Gene fĂŒr das Nitrogenase-Enzym diazotropher Organismen zu ĂŒberprĂŒfen. Die Methoden zielen auf das nifHGen und seine Transkripte und geben Aufschluss ĂŒber das Potential fĂŒr Stickstofffixierung. Die Ergebnisse werden zeigen, ob das Gen aktiv in der Plankton-Gemeinschaft transkribiert wird. Ferne wird mit der DNA Sequenzanalyse neben der Anwesenheit auch die DiversitĂ€t der diazotrophen Organismen etabliert. Schließlich wird im Verlauf der Fahrt an einer Station im Rhodos-Becken eine Sedimentfalle ausgebracht.Meteor expedition 71 has a total of 50 ship days on 3 individual legs. Research is directed towards investigations into deep-sea biology and biogeochemistry of the eastern Mediterra-nean Sea. Goals of the individual legs are: Leg Meteor M71/1 focuses on physical, biogeochemical and biological sampling at the Anaximander Mountains. There are only very few seamount-like structures in the eastern Mediterranean. They are fairly isolated from the world ocean and are located in a region with exceptionally high temperatures of 14 °C in the deep-water layers. The primary goal of the studies at one peak of the Anaximander Mountains is to assess if a seamount ecosystem in an oligotrophic region with a warm deep-water layer is comparable with similar topographic feature in the NEAtlantic, which have been studied within the EU funded project OASIS. In particular, we plan to study if these systems in different oceanographic regimes have similar impacts on the current field and on the particle flux, and if they are similar with regard to their productivity, the distribution of their food webs and their sphere of interference, i.e. the extention of the space which is affected by seamount processes. Leg METEOR 71-2 studies the biodiversity of the deep sea in the eastern Mediterranean Sea and controlling factors (water depth, distance to land, nutrient availability). One goal is to assess the species composition in two reference fields through repeated sampling of the sea floor. The second goal is to map differences in assemblages and species richness in relation to water depth and distance from land. The two reference fields of 17nm x 5 nm are located in the Ierapetra-Deep south of Crete (water depth >4000 m) and an area of the same size located furhter south (water depth 2800m double distance to the coast)The on-board investigations extend to all size classes of benthic organisms (mega-, macro-, meio-, and nanofauna) in order to search for similarities and differences that determine biodiversity and its relationship with ecosystem boundary conditions. This work will result in an improved and detailed understanding of ecosystem structure and functioning in an ultraoligotrophic sea floor region of the Eastern Mediterranean. Work on M71-3 aims to answer the question whether phosphate loss and incomplete utilisation of nitrate on the one hand, or dinitrogen fixation on the other hand are responsible for unusual nutrient ratios in the water column of the eastern Mediterranean Sea. We also seek to find the reason for unusually depleted 15N/14N ratios in dissolved nitrate, suspended matter and surface sediments of that oligotrophic ocean basin. During a total of 18 days of ship time on r/v METEOR, Leg 3 OF M71 will perfom water column and surface sediment work in the eastern Mediterranean Sea (Heraklion-Istanbul). Stations will be aligned on one E-W and two N-S transects and will sample all major basins and water masses. We will analyse water samples for nutrients, and will determine the stable nitrogen isotope composition of dissolved nitrate, suspended matter, and surface sediments. In addition, phytoplankton samples will be taken and experiments will be carried out to determine N2 fixation rates, genetic expressions of nitrogen fixation, and the composition of microbial and algal assemblages. One mooring of sediment traps (Rhodes Gyre) will be deployed and recovered after one year to monitor changes in particle flux and its isotopic signature over a seasonal cycle. An ancillary goal is to sample surface sediments for determinations of diagenetic effects on the 15N/14N signal in combination with analyses of amino acid degradation and calibration of the alkenone unsaturation index UK’ 37

    Research vessel Meteor, cruise no. 48 : 6 July - 3 November 2000

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    Die fĂŒnf Abschnitte der Meteor-Reise 48 fĂŒhren in die Zone der Ostrandzirkulation des SĂŒdost-Atlantiks und verknĂŒpfen ozeanografische, biologische, geologische und chemische Arbeiten im Bereich des Auftriebsgebietes vor der sĂŒdwest-afrikanischen KĂŒste sowie im Pelagial des Angolabeckens und des Kapbeckens. Die Arbeiten konzentrieren sich auf · die BiodiversitĂ€t von Benthosgemeinschaften in Tiefseebecken, · biogeochemische StoffkreislĂ€ufe und kurzskalige holozĂ€ne Klimavariationen im Auftriebsgebiet vor Namibia, · die Dynamik des Angola Domes und des Benguelastromes und die Entstehung des SĂŒdĂ€quatorialen Gegenstroms im Atlantik, · die Verteilungen von Spurenelementen und natĂŒrlichen Radionukliden im Auftriebsgebiet vor Namibia, · den Einfluss mesoskaliger physikalischer Strukturen und Prozesse auf die Produktion des Zooplanktons im nördlichen Benguela-Auftriebssystem.The five legs of Meteor cruise 48 lead into the eastern boundary circulation of the south-eastern Atlantic, combining oceanographical, biological, geological, and chemical work in the upwelling area off the coast of Namibia and the pelagic region of the Angola and the Cape basin. Studies focus on · biodiversity of the benthos community in deep sea basins, · biogeochemical cycles and short-scale holocene climate variations in the Namibia upwelling region, · dynamics of the Angola dome and the Benguela current, and the formation of the southequatorial contercurrent in the Atlantic, · distributions of (essential) trace elements and natural radionuclides in the Namibia upwelling region · the influence of mesoscale physical structures/processes on the production of zooplankton in the northern Benguela upwelling system

    The impact of intertidal areas on the carbonate system of the southern North Sea

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    The coastal ocean is strongly affected by ocean acidification because of its shallow water depths, low volume, and the closeness to terrestrial dynamics. Earlier observations of dissolved inorganic carbon (DIC) and total alkalinity (TA) in the southern part of the North Sea, a northwest European shelf sea, revealed lower acidification effects than expected. It has been assumed that anaerobic degradation and subsequent TA release in the adjacent back-barrier tidal areas (Wadden Sea) in summertime is responsible for this phenomenon. In this study the exchange rates of TA and DIC between the Wadden Sea tidal basins and the North Sea and the consequences for the carbonate system in the German Bight are estimated using a 3D ecosystem model. The aim of this study is to differentiate the various sources contributing to observed high summer TA in the southern North Sea. Measured TA and DIC in the Wadden Sea are considered as model boundary conditions. This procedure acknowledges the dynamic behaviour of the Wadden Sea as an area of effective production and decomposition of organic material. According to the modelling results, 39 Gmol TA yr−1 were exported from the Wadden Sea into the North Sea, which is less than a previous estimate but within a comparable range. The interannual variabilities in TA and DIC, mainly driven by hydrodynamic conditions, were examined for the years 2001–2009. Dynamics in the carbonate system are found to be related to specific weather conditions. The results suggest that the Wadden Sea is an important driver for the carbonate system in the southern North Sea. On average 41 % of TA inventory changes in the German Bight were caused by riverine input, 37 % by net transport from adjacent North Sea sectors, 16 % by Wadden Sea export, and 6 % were caused by internal net production of TA. The dominant role of river input for the TA inventory disappears when focusing on TA concentration changes due to the corresponding freshwater fluxes diluting the marine TA concentrations. The ratio of exported TA versus DIC reflects the dominant underlying biogeochemical processes in the Wadden Sea. Whereas aerobic degradation of organic matter played a key role in the North Frisian Wadden Sea during all seasons of the year, anaerobic degradation of organic matter dominated in the East Frisian Wadden Sea. Despite the scarcity of high-resolution field data, it is shown that anaerobic degradation in the Wadden Sea is one of the main contributors of elevated summer TA values in the southern North Sea

    Impact of meteorological conditions on airborne fine particle composition and secondary pollutant characteristics in urban area during winter-time

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    The assessment of airborne fine particle composition and secondary pollutant characteristics in the case of Augsburg, Germany, during winter (31 January–12 March 2010) is studied on the basis of aerosol mass spectrometry (3 non-refractory components and organic matter, 3 positive matrix factorizations (PMF) factors), particle size distributions (PSD, 5 size modes, 5 PMF factors), further air pollutant mass concentrations (7 gases and VOC, black carbon, PM10, PM2.5) and meteorological measurements, including mixing layer height (MLH), with one-hourly temporal resolution. Data were subjectively assigned to 10 temporal phases which are characterised by different meteorological influences and air pollutant concentrations. In each phase hierarchical clustering analysis with the Ward method was applied to the correlations of air pollutants, PM components, PM source contributions and PSD modes and correlations of these data with all meteorological parameters. This analysis resulted in different degrees of sensitivities of these air pollutant data to single meteorological parameters. It is generally found that wind speed (negatively), MLH (negatively), relative humidity (positively) and wind direction influence primary pollutant and accumulation mode particle (size range 100–500 nm) concentrations. Temperature (negatively), absolute humidity (negatively) and also relative humidity (positively) are relevant for secondary compounds of PM and particle (PM2.5, PM10) mass concentrations. NO, nucleation and Aitken mode particle and the fresh traffic aerosol concentrations are only weakly dependent on meteorological parameters and thus are driven by emissions. These daily variation data analyses provide new, detailed meteorological influences on air pollutant data with the focus on fine particle composition and secondary pollutant characteristics and can explain major parts of certain PM component and gaseous pollutant exposure

    SmartAQnet: remote and in-situ sensing of urban air quality

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    our time. However, it is very difficult for many cities to take measures to accommodate today’s needs concerning e.g. mobility, housing and work, because a consistent fine-granular data and information on causal chains is largely missing. This has the potential to change, as today, both large-scale basic data as well as new promising measuring approaches are becoming available. The project “SmartAQnet”, funded by the German Federal Ministry of Transport and Digital Infrastructure (BMVI), is based on a pragmatic, data driven approach, which for the first time combines existing data sets with a networked mobile measurement strategy in the urban space. By connecting open data, such as weather data or development plans, remote sensing of influencing factors, and new mobile measurement approaches, such as participatory sensing with low-cost sensor technology, “scientific scouts” (autonomous, mobile smart dust measurement device that is auto-calibrated to a high-quality reference instrument within an intelligent monitoring network) and demand-oriented measurements by light-weight UAVs, a novel measuring and analysis concept is created within the model region of Augsburg, Germany. In addition to novel analytics, a prototypical technology stack is planned which, through modern analytics methods and Big Data and IoT technologies, enables application in a scalable way

    SmartAQnet 2020: A New Open Urban Air Quality Dataset from Heterogeneous PM Sensors

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    The increasing attention paid to urban air quality modeling places higher requirements on urban air quality datasets. This article introduces a new urban air quality dataset—the SmartAQnet2020 dataset—which has a large span and high resolution in both time and space dimensions. The dataset contains 248,572,003 observations recorded by over 180 individual measurement devices, including ceilometers, Radio Acoustic Sounding System (RASS), mid- and low-cost stationary measuring equipment equipped with meteorological sensors and particle counters, and low-weight portable measuring equipment mounted on different platforms such as trolley, bike, and UAV

    Epidemic Microclusters of Blood-Culture Proven Sepsis in Very-Low-Birth Weight Infants: Experience of the German Neonatal Network

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    INTRODUCTION: We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010. METHODS: Thirty-seven centers participated in GNN; 23 centers enrolled ≄50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same bacterial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gram-negative rods and Enterococcus spp. RESULTS: In our cohort, 12/2110 (0.6%) infants were documented with an early-onset sepsis and 235 late-onset sepsis episodes (≄72 h of age) occurred in 203/2110 (9.6%) VLBW infants. In 182/235 (77.4%) late-onset sepsis episodes gram-positive bacteria were documented, while coagulase negative staphylococci were found to be the most predominant pathogens (48.5%, 95%CI: 42.01-55.01). Candida spp. and gram-negative bacilli caused 10/235 (4.3%, 95%CI: 1.68% -6.83%) and 43/235 (18.5%) late-onset sepsis episodes, respectively. Eleven microclusters of blood-culture proven sepsis were detected in 7 hospitals involving a total 26 infants. 16/26 cluster patients suffered from Klebsiella spp. sepsis. The median time interval between the first patient's Klebsiella spp. sepsis and cluster cases was 14.1 days (interquartile range: 1-27 days). First patients in the cluster, their linked cases and sporadic sepsis events did not show significant differences in short term outcome parameters. DISCUSSION: Microclusters of infection are an important phenomenon for late-onset sepsis. Most gram-negative cluster infections occur within 30 days after the first patient was diagnosed and Klebsiella spp. play a major role. It is essential to monitor epidemic microclusters of sepsis in surveillance networks to adapt clinical practice, inform policy and further improve quality of care

    SmartAQnet – neuer smarter Weg zur rĂ€umlichen Erfassung von Feinstaub

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    Mit dem Forschungsprojekt SmartAQnet wird ein smarter Weg zur rĂ€umlichen Bestimmung von Feinstaub untersucht und am Modellstandort Augsburg erprobt. Forschungsansatz ist die Erfassung und ZusammenfĂŒhrung unterschiedlicher QualitĂ€ten von Feinstaubmesswerten mit Fernerkundungsdaten. Feinstaubmesswerte können hierbei von Jedermann (z. B. mit Ultra-Low-Cost-Sensoren) bis hin zu offiziellen Messnetzen (mit hochprĂ€ziser Messtechnik) in die Datenarchitektur eingespeist werden. Eine neuartige Internet-of-Things-Analyseplattform soll Daten zur Anwendung sowohl fĂŒr Planer als auch fĂŒr den BĂŒrger bieten, welche der nachhaltigen Gesundheitsvorsorge dienen können (z. B. App fĂŒr eine luftqualitĂ€tsbezogene Navigation)
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