ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Capillaria hepatica  (1)
  • Lateral sediment distribution  (1)
  • American Geophysical Union  (1)
  • Springer  (1)
  • 2010-2014  (1)
  • 1980-1984  (1)
Collection
Publisher
  • American Geophysical Union  (1)
  • Springer  (1)
Years
  • 2010-2014  (1)
  • 1980-1984  (1)
Year
  • 1
    ISSN: 1432-1955
    Keywords: Capillaria hepatica ; X-ray attenuation ; Immunization ; Capillaria hepatica ; Röntgenstrahlenaltenuierung ; Immunisierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß von Erstinfektionen mit embryonierten Eiern, von röntgenattenuierten Stadien, von nicht embryonierten Eiern und löslichen Eiextrakten auf Belastungsinfektionen mitCapillaria hepatica wurde untersucht. Die Reproduktivität einer Wurmpopulation aus einer subletalen Belastungsinfektion wurde inMastomys natalensis durch eine 11 Tage vorher gesetzte Erstinfektion mit 50, 150, 400 oder 800 embryonierten Eiern/Tier signifikant reduziert. Ein signifikanter Einfluß von röntgenattenuierten, infektiösen Eiern bzw. von intraperitoneal injizierten, nicht embryonierten Eiern (bei steigenden Dosen über 10 Tage wurde die Eiproduktion normaler Infektionen simuliert) beschränkte sich auf schwache (50 Eier/Tier) Belasnungsinfektionen. Die Kombination attenuierten Infektionsmaterials mit nicht embryonierten Eiern i.p. führte zu keiner gesteigerten Wirkung. In Albinomäusen ließ sich durch vorherige, wiederholte subkutane Injektion von löslichen Eiextrakten die Eiproduktion einer mittleren Belastungsinfektion bis zum 60. Tag p.i. hochsignifikant reduzieren. Die durch Infektionsdosen von 230 embryonierten Eiern/g Körpergewicht beiM. natalensis zwischen dem 20. und 35. Tag p.i. 100% erreichende Mortalität ließ sich durch vorherige Applikation von 50, 150, 400 und 800 Eiern/Tier bei nach 36 und 52 Tagen gesetzten Belastungsinfektionen auf 0–30% reduzieren. Bei Verwendung attenuierten Infektionsmaterials war für einen 70–80% igen Schutz eine wiederholte Vakzinierung notwendig. Die intraperitoneale Injektion von nicht embryonierten Eiern führte bei 40% der Tiere zu einem Schutz. Der Eintritt des Todes verzögerte sich i.d.R. bei vorbehandelten Tieren.
    Notes: Abstract The influence of primary infections with embryonated infective eggs or with X-irradiated infective eggs, and of non-embryonated eggs, and egg homogenate extracts on challenge infections withCapillaria hepatica was investigated. The worm reproductivity was significantly suppressed in a sublethal challenge infection given 11 days after a primary infection ofMastomys natalensis with 50, 150, 400, and 800 eggs per animal. The administration of 600 X-irradiated (2.2 Krd) embryonated eggs 36 days before challenge as well as an intraperitoneal injection of non-embryonated eggs 12, 10, 8, 6, 4, and 2 days before challenge (simulating the egg production of a normal infection) also reduced significantly the egg production of a weak (50 eggs/animal) infection. No effect was observed on a moderate challenge (300 eggs/animal). The effect was not markedly enhanced by the repeated administration of X-irradiated eggs or by the combination of X-irradiated infective eggs and non-embryonated eggs. Immunization of mice with soluble egg extracts resulted in significant reduction of egg production determined 60 days after challenge. Two hundred and thirty eggs ofC. hepatica/g bodyweight proved to be a lethal infection dose forM. natalensis. The animals died between 20 and 35 days after infection. After single infections with 50, 150, 400, or 800 eggs per animal the mortality ofMastomys challenged 36 or 52 days later was reduced to 0–30%. Using X-irradiated embryonated eggs for immunization only repeated administration led to protection in 70 to 80% of the animals. About 40% of the animals could be protected by the intraperitoneal injection of non-embryonated eggs. If death occurred it was delayed. The combination of X-irradiated stages and eggs did not enhance the protection.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C10013, doi:10.1029/2012JC008124.
    Description: Analyses of field observations and numerical model results have identified that sediment transport in the Hudson River estuary is laterally segregated between channel and shoals, features frontal trapping at multiple locations along the estuary, and varies significantly over the spring-neap tidal cycle. Lateral gradients in depth, and therefore baroclinic pressure gradient and stratification, control the lateral distribution of sediment transport. Within the saline estuary, sediment fluxes are strongly landward in the channel and seaward on the shoals. At multiple locations, bottom salinity fronts form at bathymetric transitions in width or depth. Sediment convergences near the fronts create local maxima in suspended-sediment concentration and deposition, providing a general mechanism for creation of secondary estuarine turbidity maxima at bathymetric transitions. The lateral bathymetry also affects the spring-neap cycle of sediment suspension and deposition. In regions with broad, shallow shoals, the shoals are erosional and the channel is depositional during neap tides, with the opposite pattern during spring tides. Narrower, deeper shoals are depositional during neaps and erosional during springs. In each case, the lateral transfer is from regions of higher to lower bed stress, and depends on the elevation of the pycnocline relative to the bed. Collectively, the results indicate that lateral and along-channel gradients in bathymetry and thus stratification, bed stress, and sediment flux lead to an unsteady, heterogeneous distribution of sediment transport and trapping along the estuary rather than trapping solely at a turbidity maximum at the limit of the salinity intrusion.
    Description: This research was funded by a grant from the Hudson River Foundation (#002/07A). D.R. was partially supported by the Office of Naval Research (N00014-08-1-0846).
    Description: 2013-04-17
    Keywords: Estuarine turbidity maximum ; Lateral sediment distribution ; Salinity fronts ; Sediment flux ; Sediment trapping ; Stratification
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...