32 research outputs found

    Potential contribution of surface-dwelling Sargassum algae to deep-sea ecosystems in the southern North Atlantic

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    Deep-sea ecosystems, limited by their inability to use primary production as a source of carbon, rely on other sources to maintain life. Sedimentation of organic carbon into the deep sea has been previously studied, however, the high biomass of sedimented Sargassum algae discovered during the VEMA Transit expedition in 2014/2015 to the southern North Atlantic, and its potential as a regular carbon input, has been an underestimated phenomenon. To determine the potential for this carbon flux, a literature survey of previous studies that estimated the abundance of surface water Sargassum was conducted. We compared these estimates with quantitative analyses of sedimented Sargassum appearing on photos taken with an autonomous underwater vehicle (AUV) directly above the abyssal sediment during the expedition. Organismal communities associated to Sargassum fluitans from surface waters were investigated and Sargassum samples collected from surface waters and the deep sea were biochemically analyzed (fatty acids, stable isotopes, C:N ratios) to determine degradation potential and the trophic significance within deep-sea communities. The estimated Sargassum biomass (fresh weight) in the deep sea (0.07 − 3.75 g/m2) was several times higher than that estimated from surface waters in the North Atlantic (0.024 – 0.84 g/m2). Biochemical analysis showed degradation of Sargassum occurring during sedimentation or in the deep sea, however, fatty acid and stable isotope analysis did not indicate direct trophic interactions between the algae and benthic organisms. Thus, it is assumed that components of the deep-sea microbial food web form an important link between the macroalgae and larger benthic organisms. Evaluation of the epifauna showed a diverse nano- micro-, meio, and macrofauna on surface Sargassum and maybe transported across the Atlantic, but we had no evidence for a vertical exchange of fauna components. The large-scale sedimentation of Sargassum forms an important trophic link between surface and benthic production and has to be further considered in the future as a regular carbon input to the deep-sea floor in the North Atlantic

    Operating Cabled Underwater Observatories in Rough Shelf-Sea Environments:A Technological Challenge

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    Cabled coastal observatories are often seen as future-oriented marine technology that enables science to conduct observational and experimental studies under water year-round, independent of physical accessibility to the target area. Additionally, the availability of (unrestricted) electricity and an Internet connection under water allows the operation of complex experimental setups and sensor systems for longer periods of time, thus creating a kind of laboratory beneath the water. After successful operation for several decades in the terrestrial and atmospheric research field, remote controlled observatory technology finally also enables marine scientists to take advantage of the rapidly developing communication technology. The continuous operation of two cabled observatories in the southern North Sea and off the Svalbard coast since 2012 shows that even highly complex sensor systems, such as stereo-optical cameras, video plankton recorders or systems for measuring the marine carbonate system, can be successfully operated remotely year-round facilitating continuous scientific access to areas that are difficult to reach, such as the polar seas or the North Sea. Experience also shows, however, that the challenges of operating a cabled coastal observatory go far beyond the provision of electricity and network connection under water. In this manuscript, the essential developmental stages of the "COSYNA Shallow Water Underwater Node" system are presented, and the difficulties and solutions that have arisen in the course of operation since 2012 are addressed with regard to technical, organizational and scientific aspects.</p

    Biogeochemical relationships between ultrafiltered dissolved organic matter and picoplankton activity in the Eastern Mediterranean Sea

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 57 (2010): 1460-1477, doi:10.1016/j.dsr2.2010.02.015.We targeted the warm, subsurface waters of the Eastern Mediterranean Sea (EMS) to investigate processes that are linked to the chemical composition and cycling of dissolved organic carbon (DOC) in seawater. The apparent respiration of semi-labile DOC accounted for 27 ± 18% of oxygen consumption in EMS mesopelagic and bathypelagic waters; this value is higher than that observed in the bathypelagic open ocean, so the chemical signals that accompany remineralization of DOC may thus be more pronounced in this region. Ultrafiltered dissolved organic matter (UDOM) collected from four deep basins at depths ranging from 2 to 4350 m exhibited bulk chemical (1H-NMR) and molecular level (amino acid and monosaccharide) abundances, composition, and spatial distribution that were similar to previous reports, except for a sample collected in the deep waters of the N. Aegean Sea that had been isolated for over a decade. The amino acid component of UDOM was tightly correlated with apparent oxygen utilization and prokaryotic activity, indicating its relationship with remineralization processes that occur over a large range of timescales. Principal component analyses of relative mole percentages of monomers revealed that oxygen consumption and prokaryotic activity were correlated with variability in amino acid distributions but not well correlated with monosaccharide distributions. Taken together, this study elucidates key relationships between the chemical composition of DOM and heterotrophic metabolism.TBM and AG acknowledge funding from the Hellenic GSRT/European Union (non-EU Grant No180) and SESAME Project (European Commission's Sixth Framework Program, EC Contract No GOCE-036949). TY was supported by the Japanese Society for the Promotion of Science (JSPS) Postdoctoral Fellowship for research abroad and DDC received a fellowship of the University of Groningen. Microbial laboratory work and molecular analyses were supported by a grant of the Earth and Life Science Division of the Dutch Science Foundation (ARCHIMEDES project, 835.20.023) to GJH. DJR and TBM were supported by grants from the Gordon and Betty Moore Foundation and from the C-MORE organization of NSF

    A longitudinal twin family study of the life course and individual development (TWINLIFE): Data collection and instruments of wave 1 face-to-face interviews

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    Brix J, Pupeter M, Rysina A, et al. A longitudinal twin family study of the life course and individual development (TWINLIFE): Data collection and instruments of wave 1 face-to-face interviews. TwinLife Technical Report Series. Vol 05. Bielefeld: Project TwinLife "Genetic and social causes of life chances" (Universität Bielefeld / Universität des Saarlandes); 2017

    Strategy for the management of diabetic macular edema: the European Vitreo-Retinal Society macular edema study

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    Objective. To compare the efficacy of different therapies in the treatment of diabetic macular edema (DME). Design. Nonrandomized, multicenter clinical study. Participants. 86 retina specialists from 29 countries provided clinical information on 2,603 patients with macular edema including 870 patients with DME. Methods. Reported data included the type and number of treatment(s) performed, the pre-and posttreatment visual acuities, and other clinical findings.The results were analyzed by the French INSEE (National Institute of Statistics and Economic Studies). Main Outcome Measures. Mean change of visual acuity and mean number of treatments performed. Results.The change in visual acuity over time in response to each treatment was plotted in second order polynomial regression trend lines. Intravitreal triamcinolone monotherapy resulted in some improvement in vision. Treatmentwith threshold or subthreshold grid laser also resulted in minimal vision gain. Anti-VEGF therapy resulted in more significant visual improvement. Treatment with pars plana vitrectomy and internal limiting membrane (ILM) peeling alone resulted in an improvement in vision greater than that observed with anti-VEGF injection alone. In our DME study, treatment with vitrectomy and ILM peeling alone resulted in the better visual improvement compared to other therapies

    Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease

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    Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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    Facial Rejuvenation with Concentrated Lipograft—A 12 Month Follow-Up Study

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    and stromal vascular fraction cells, which include adipose-derived stem cells (ASC). We hypothesize that the patient’s wrinkle severity scale (WSS) and patient’s satisfaction on the global aesthetic improvement scale (GAIS) can be improved after using concentrated lipoaspirate. Fourteen patients (54 years ± 11.09 years) with volume loss in the midface area underwent waterjet-assisted liposuction (Human Med AG, Schwerin, Germany). Fat was centrifuged in an ACP Double Syringe (Arthrex GmbH, Munich, Germany) using Rotofix 32A centrifuge (Andreas Hettich, GmbH & Co.KG, Tuttlingen, Germany). Homogenization was performed using the double syringe and a 1.4 mm female–female luerlock connector. After a second centrifugation, patients received periorbital (PO) and nasolabial (NL) lipografting. ASC count was performed after enzymatical digestion. Vitality of cells was assessed using a resazurin assay. During long-term follow up (12 months, n = 10), we found a high patient’s satisfaction (GAIS 1+/−0.52) and a good improvement of the WSS during short- and long-term follow-up. The ASC count of processed lipoaspirate was 2.1-fold higher than of unprocessed lipoaspirate (p < 0.001). The difference of ASC in sedimented and simply centrifuged lipoaspirate was also significant (p < 0.05). Facial rejuvenation with concentrated fat graft offers good results concerning objective aesthetic outcome and patient’s satisfaction
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