GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (8)
  • Springer  (4)
  • ELSEVIER SCIENCE BV  (3)
  • Springer Science and Business Media LLC  (1)
Document type
  • Articles  (8)
Publisher
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Geometriae dedicata 79 (2000), S. 299-320 
    ISSN: 1572-9168
    Keywords: symplectic module ; symplectic module of convex type ; invariant cone ; Lie algebra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper we give a classification of a certain class of semisimple symplectic structures, more precisely all symplectic structures Ω for which a symplectic module (V,Ω) is of convex type. This classification then leads to a classification of Lie algebras with invariant cones and at most one dimensional center.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archiv der Mathematik 51 (1988), S. 496-499 
    ISSN: 1420-8938
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    HNO 47 (1999), S. 1074-1088 
    ISSN: 1433-0458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Nachdem die Prinzipien der Tympanoplastik durch Moritz [46], Wullstein [63] und Zöllner [67] vorgestellt und international anerkannt wurden und Wullstein selbst 1952 Spalthauttransplantate als Trommelfellersatz inaugurierte, wurde die Verwendung von Faszie als Trommelfellersatz 1957 von Unterberger [58], 1960 von H. Heermann [24] und 1963 von Kley [38] vorgeschlagen. Andere autologe mesodermale Gewebearten vie Vene (Shea 1960 [52]) und Periost (Agazzi 1960 [2]) konnten sich ebensowenig durchsetzten wie homologes Trommelfell (Betow 1970 [6]) oder lyophilisierte Dura (Gerhardt und Mahler 1970 [17]). Faszie des musculus temporalis ist somit das international etablierte und am häufigsten verwendete Transplantatmaterial zum Trommelfellersatz in der Mikrochirurgie des Mittelohres.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Semigroup forum 61 (2000), S. 57-85 
    ISSN: 1432-2137
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: G/H be an irreducible globally hyperbolic semisimple symmetric space, and let S⊆G be a subsemigroup containing H not isolated in S. We show that if S o ≠ 0 then there are H-invariant minimal and maximal cones C min⊆C max in the tangent space at the origin such that H exp C min⊆S⊆HZ K (a)expC max. A double coset decomposition of the group G in terms of Cartan subspaces and the group H is proved. We also discuss the case where G/H is of Cayley type.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    ELSEVIER SCIENCE BV
    In:  EPIC3Journal of Sea Research, ELSEVIER SCIENCE BV, ISSN: 1385-1101
    Publication Date: 2017-02-02
    Description: As the determinant of solute and particle fluxes through sediments, quantifying sediment permeability is vital step in understanding of the exchange phenomena between the water column and sediment as permeability determines the mode and intensity of solute and particle fluxes. Reliable estimates of sediment permeability are therefore a constraint on the accurate implementation of benthic biogeochemical models. This is particularly true for the North Sea, as field data are scarce and available grain-size-based models fail to represent the full range of sediment types. In this study, we combine measurements of sediment permeability and grain size analysis with a generic permeability model to establish a high-resolution permeability map of the sediment in the German Bight (North Sea). Our results show a good agreement between model-based prediction and measurements of permeability, even for a wide range of permeability values.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    facet.materialart.
    Unknown
    ELSEVIER SCIENCE BV
    In:  EPIC3Journal of Sea Research, ELSEVIER SCIENCE BV, ISSN: 1385-1101
    Publication Date: 2021-01-26
    Description: Denitrification on continental margins and in coastal sediments is a major sink of reactive N in the present nitrogen cycle and a major ecosystem service of eutrophied coastal waters. We analyzed the nitrate removal in surface sediments of the Elbe estuary, Wadden Sea, and adjacent German Bight (SE North Sea) during two seasons (spring and summer) along a eutrophication gradient ranging from a high riverine nitrate oncentrations at the Elbe Estuary to offshore areas with low nitrate concentrations. The gradient encompassed the full range of sediment types and organic carbon concentrations of the southern North Sea. Based on nitrate penetration depth and concentration gradient in the porewater we estimated benthic nitrate consumption rates assuming either diffusive transport in cohesive sediments or advective transport in permeable sediments. For the latter we derived a mechanistic model of porewater flow. During the peak nitrate discharge of the river Elbe in March, the highest rates of diffusive nitrate uptake were observed in muddy sediments (up to 2.8 mmol m−2 d−1). The highest advective uptake rate in that period was observed in permeable sediment and was tenfold higher (up to 32 mmol m−2 d−1). The intensity of both diffusive and advective nitrate consumption dropped with the nitrate availability and thus decreased from the Elbe estuary towards offshore stations, and were further decreased during late summer (minimum nitrate discharge) compared to late winter (maximum nitrate discharge). In summary, our rate measurements indicate that the permeable sediment accounts for up to 90% of the total benthic reactive nitrogen consumption in the study area due to the high efficiency of advective nitrate transport into permeable sediment. Extrapolating the averaged nitrate consumption of different sediment classes to the areas of Elbe Estuary, Wadden Sea and eastern German Bight amounts to an N-loss of 3.1 ∗ 106 mol N d−1 from impermeable, diffusion-controlled sediment, and 5.2 ∗ 107 mol N d−1 from permeable sediment with porewater advection.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    ELSEVIER SCIENCE BV
    In:  EPIC3Earth-Science Reviews, ELSEVIER SCIENCE BV, 221(103803), ISSN: 0012-8252
    Publication Date: 2022-08-21
    Description: Benthic organisms and their bioturbation activities have a profound effect on a multitude of sediment properties. While many studies have already explored benthic impacts at small temporal and spatial scales, little is known on how the small-scale effects accumulate and interactively guide large-scale (km-scale) morphological evolution. Here we firstly summarize the most important processes of benthos affecting sediment stability and then explore existing biomorphodynamic modeling studies both at small- and large-scales. In general, microbenthos (body size 〈0.1 mm) mainly stabilizes sediments while meio- (0.1–1 mm) and macrobenthos (〉1 mm) may stabilize or destabilize sediments. Among all types of sediment, fine-grained fraction (silt and clay) is most sensitive to the impact of benthos. Benthic organisms have the capability to mediate sediment transport and sedimentation patterns beyond their habitats on the long-term and over a large-scale. However, so far, numerical models evaluating benthic impact are limited to explorative studies and have not reached a stage where they can be used for predictive modeling. The barriers hindering a further development of biomorphodynamic models include not only limited understanding of fundamental biological/bio-physical processes affecting morphological development and dynamic feedback loops among them but also a shortage of data for model calibration and confirmation of simulation results. On the other hand, thriving for higher model complexity does not necessarily lead to better performance. Before conducting biomorphodynamic modeling, researchers must figure out which questions can be answered in a meaningful sense with simulation results that can be compared with observations and which level of modeling complexity is sufficient for that purpose.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , NonPeerReviewed
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2023-12-16
    Description: Microbial composition and diversity in marine sediments are shaped by environmental, biological, and anthropogenic processes operating at different scales. However, our understanding of benthic microbial biogeography remains limited. Here, we used 16S rDNA amplicon sequencing to characterize benthic microbiota in the North Sea from the top centimeter of 339 sediment samples. We utilized spatially explicit statistical models, to disentangle the effects of the different predictors, including bottom trawling intensity, a prevalent industrial fishing practice which heavily impacts benthic ecosystems. Fitted models demonstrate how the geographic interplay of different environmental and anthropogenic drivers shapes the diversity, structure and potential metabolism of benthic microbial communities. Sediment properties were the primary determinants, with diversity increasing with sediment permeability but also with mud content, highlighting different underlying processes. Additionally, diversity and structure varied with total organic matter content, temperature, bottom shear stress and bottom trawling. Changes in diversity associated with bottom trawling intensity were accompanied by shifts in predicted energy metabolism. Specifically, with increasing trawling intensity, we observed a transition toward more aerobic heterotrophic and less denitrifying predicted metabolism. Our findings provide first insights into benthic microbial biogeographic patterns on a large spatial scale and illustrate how anthropogenic activity such as bottom trawling may influence the distribution and abundances of microbes and potential metabolism at macroecological scales.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...