GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Hybrid of pikeperch, Sander lucioperca L. and Volga perch, S. volgense (Gmelin) (2004)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 35 (2004), S. 0 
    Details
    ISSN: 1365-2109
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2109.2004.01088.x
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Cryopreservation of Sperm of Farmed European Eel Anguilla anguilla (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 35 (2004), S. 0 
    Details
    ISSN: 1749-7345
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Sexual maturation and sperm release were induced in farmed European eels Anguilla anguilla kept exclusively in fresh water by using two dosages of human chorion gonadotropin (100 International Unit (IU)-Group one and 250 IU/individual per week-Group two). Sperm release took over 13 wk in both groups. The quality of sperm was investigated on the eighth, ninth, and tenth wk. The average cell densities were 0.94 ± 0.4 × 1010 (Group one) and 0.93 to. ± 0.6 × 1010 (Group two) spermatozoa/mL. The estimated motility of eel sperm was 33, 55, and 49% on the eighth, ninth, and tenth wk of treatment, respectively. The estimated average motility of samples selected for cryopreservation was 73 ± 10%, while the post-thaw motility of cryopreserved samples was 36 ± 11%. The extender originally developed for common carp sperm crypreservation together with methanol as cryoprotectant was found suitable for the cryopreservation of European eel sperm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1749-7345.2004.tb01078.x
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Following the Artificially Induced Eel Maturation Process by Means of In Vivo CT Scanning (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 35 (2004), S. 0 
    Details
    ISSN: 1749-7345
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Artificially induced maturation of 10 male eels Anguilla anguilla L. weighing 170 ± 30-3 g was followed for 6 wk with in vivo CT scanning in a repeated manner. Since testis tissue has a well defined X-ray density value, the volumetric development could be described. Parallel with this process, a strong decrease of the abdominal fat volume was measured and depicted with the applied surface smoothing method. As an affect of the hCG treatment (250 IU/week per eel) at the third wk, the testis could clearly be recognized on the images. From that time the average testis volume values of the 10 eels were 4,975, 6345, 11,583 and 14,553 mmJ respectively. At the sixth wk, the relative testis volume in the abdomen was 25%. In the fillet a characteristic shift (from -10 to -20 Hounsfield units) of the density histogram towards the fat interval was detected. The average density value of the fillet was found to be zero; this was supported furthermore by the histological analysis of the fillet (fat to muscle rate 0.35-0.40). On the basis of the above findings, the applied CT scanning method was proven to be suitable to follow in vivo the maturation process of male eels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1749-7345.2004.tb01077.x
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    facet.materialart.
    Unbekannt
    The evolution of thecideide microstructures and textures: traced from Triassic to Holocene (2021)
    Details
    Publikationsdatum: 2021-07-21
    Beschreibung: Thecideide brachiopods are an anomalous group of invertebrates. In this study, we discuss the evolution of thecideide brachiopods from the Triassic to the Holocene and base our results and conclusions on microstructure and texture measurements gained from electron backscatter diffraction (EBSD). In fossil and Recent thecideide shells, we observe the following mineral units: (1) nanometric to small granules; (2) acicles; (3) fibres; (4) polygonal crystals; and (5) large roundish crystals. We trace for thecideide shells the change of mineral unit characteristics such as morphology, size, orientation, arrangement and distribution pattern. Triassic thecideide shells contain extensive sections formed of fibres interspersed with large, roundish crystals. Upper Cretaceous to Pleistocene thecideide hard tissues consist of a matrix of minute to small grains reinforced by acicles and small polygonal crystals. Recent thecideide species form their shell of mineral units that show a wide range of shapes, sizes and arrangements. We find from Late Triassic to Recent a gradual decrease in mineral unit size, regularity of mineral unit morphology and orientation and the degree of calcite co‐orientation. While crystallite co‐orientation is the highest for fibrous microstructures, it is strikingly low for taxa that form their shell out of nanogranular to acicular mineral units. Our results indicate that Upper Jurassic species represent transitional forms between ancient taxa with fibrous shells and Recent forms that construct their shells of acicles and granules. We attribute the observed changes in microstructure and texture to be an adaptation to a different habitat and lifestyle associated with cementation to hard substrates.
    Beschreibung: H2020 Marie Skłodowska‐Curie Actions http://dx.doi.org/10.13039/100010665
    Beschreibung: WOA Institution: LUDWIG‐MAXIMILIANS‐UNIVERSITAET MUNCHEN
    Schlagwort(e): 560 ; Brachiopoda ; calcite crystals ; calcite fibre ; EBSD ; shell microstructure evolution ; thecideides
    Materialart: article
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    CITATION GEO-LEO
  • 5
    facet.materialart.
    Unbekannt
    Ocean acidification during the early Toarcian extinction event: Evidence from boron isotopes in brachiopods (2020)
    GSA (Geological Society of America)
    Details
    Publikationsdatum: 2023-02-08
    Beschreibung: The loss of carbonate production during the Toarcian Oceanic Anoxic Event (T-OAE, ca. 183 Ma) is hypothesized to have been at least partly triggered by ocean acidification linked to magmatism from the Karoo-Ferrar large igneous province (southern Africa and Antarctica). However, the dynamics of acidification have never been directly quantified across the T-OAE. Here, we present the first record of temporal evolution of seawater pH spanning the late Pliensbachian and early Toarcian from the Lusitanian Basin (Portugal) reconstructed on the basis of boron isotopic composition (δ11B) of brachiopod shells. δ11B declines by ~1‰ across the Pliensbachian-Toarcian boundary (Pl-To) and attains the lowest values (~12.5‰) just prior to and within the T-OAE, followed by fluctuations and a moderately increasing trend afterwards. The decline in δ11B coincides with decreasing bulk CaCO3 content, in parallel with the two-phase decline in carbonate production observed at global scales and with changes in pCO2 derived from stomatal indices. Seawater pH had declined significantly already prior to the T-OAE, probably due to the repeated emissions of volcanogenic CO2. During the earliest phase of the T-OAE, pH increased for a short period, likely due to intensified continental weathering and organic carbon burial, resulting in atmospheric CO2 drawdown. Subsequently, pH dropped again, reaching the minimum in the middle of the T-OAE. The early Toarcian marine extinction and carbonate collapse were thus driven, in part, by ocean acidification, similar to other Phanerozoic events caused by major CO2 emissions and warming.
    Materialart: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 6
    facet.materialart.
    Unbekannt
    The evolution of thecideide microstructures and textures: traced from Triassic to Holocene (2021)
    Wiley
    Details
    Publikationsdatum: 2024-02-07
    Beschreibung: Thecideide brachiopods are an anomalous group of invertebrates. In this study, we discuss the evolution of thecideide brachiopods from the Triassic to the Holocene and base our results and conclusions on microstructure and texture measurements gained from electron backscatter diffraction (EBSD). In fossil and Recent thecideide shells, we observe the following mineral units: (1) nanometric to small granules; (2) acicles; (3) fibres; (4) polygonal crystals; and (5) large roundish crystals. We trace for thecideide shells the change of mineral unit characteristics such as morphology, size, orientation, arrangement and distribution pattern. Triassic thecideide shells contain extensive sections formed of fibres interspersed with large, roundish crystals. Upper Cretaceous to Pleistocene thecideide hard tissues consist of a matrix of minute to small grains reinforced by acicles and small polygonal crystals. Recent thecideide species form their shell of mineral units that show a wide range of shapes, sizes and arrangements. We find from Late Triassic to Recent a gradual decrease in mineral unit size, regularity of mineral unit morphology and orientation and the degree of calcite co‐orientation. While crystallite co‐orientation is the highest for fibrous microstructures, it is strikingly low for taxa that form their shell out of nanogranular to acicular mineral units. Our results indicate that Upper Jurassic species represent transitional forms between ancient taxa with fibrous shells and Recent forms that construct their shells of acicles and granules. We attribute the observed changes in microstructure and texture to be an adaptation to a different habitat and lifestyle associated with cementation to hard substrates.
    Materialart: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 7
    facet.materialart.
    Unbekannt
    Immunosenescence in vertebrates and invertebrates (2013)
    BioMed Central
    Details
    Publikationsdatum: 2013-04-03
    Beschreibung: There is an established consensus that it is primarily the adaptive arm of immunity, and the T cell subset in particular, that is most susceptible to the deleterious changes with age known as "immunosenescence". Can we garner any clues as to why this might be by considering comparative immunology and the evolutionary emergence of adaptive and innate immunity? The immune system is assumed to have evolved to protect the organism against pathogens, but the way in which this is accomplished is different in the innate-vs-adaptive arms, and it is unclear why the latter is necessary. Are there special characteristics of adaptive immunity which might make the system more susceptible to age-associated dysfunction? Given recent accumulating findings that actually there are age-associated changes to innate immunity and that these are broadly similar in vertebrates and invertebrates, we suggest here that it is the special property of memory in the adaptive immune system which results in the accumulation of cells with a restricted receptor repertoire, dependent on the immunological history of the individual's exposures to pathogens over the lifetime, and which is commonly taken as a hallmark of "immunosenescence". However, we further hypothesize that this immunological remodelling per se does not necessarily convey a disadvantage to the individual (ie. is not necessarily "senescence" if it is not deleterious). Indeed, under certain circumstances, or potentially even as a rule, this adaptation to the individual host environment may confer an actual survival advantage.
    Digitale ISSN: 1742-4933
    Thema: Medizin
    Publiziert von BioMed Central
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    PAPER CURRENT
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...