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  • 1
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations were made on the horizontal distribution of certain invertebrates on the walls and floor of the upper chamber of the Gatún Lock system of the Panama Canal. The hydroid Cordylophora caspia (Pallas) and the gastrophod Neritina usnea Röding extended the full length of the chamber; the oligochaete Marionina sp. was confined to the upper half of the chamber (adjacent to Gatún Lake), and the amphipod Gitanopsis tortugae? Shoemaker, the isopod Munna sp. and the bivalve Mytilopsis sallei (Recluz) to the lower half; the sponge Trochospongilla leidii (Bowerbank) was distributed from the upper end to near the lower end of the chamber. A peculiar wedge-shaped distribution of T. leidii is thought to be a response to the influence of slight increases in salinity. Morphological observations on T. leidii are presented.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 20 (1973), S. 78-87 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cuticular differentiations on the body surface and the pharyngeal armature of adult Tubiluchus corallicola van der Land were examined with the scanning electron microscope. The morphology of abdominal tumuli, flosculi and tubuli, and of pectinate teeth and fimbrillae on the pharynx is described, and an attempt is made to interpret their functional properties. Taking into account the structural details, relative size, and topographic arrangement in relevance to interaction with the interstitial environment, we assume that tumuli are protective, flosculi chemoreceptive, and tubuli adhesive, and that the pharyngeal armature is a scraping mechanism for feeding on epigrowth on sand grains.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 21 (1973), S. 144-162 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cliona lampa Laubenfels (Porifera: Hadromerida), a common burrowing organism in Bermuda, has been used to study the method of sponge penetration into calcareous objects. To progress beyond the results obtained by previous authors, electron-microscope techniques, in addition to light-microscope observations, were employed. Burrowing patterns, fine structure of the tissue-substratum interface and of calcareous fragments removed by sponge activity are described on the basis of scanning electron microscopy. Cell types and cytological features have been identified by light and transmission electron microscope. One cell type of archeocyte origin is demonstrated; it carves out chips of calcium carbonate (and conchiolin) by means of filopodial extensions and etching secretions. The cells undergo plasmolysis during this process; the substratum chips are expelled through the exhalent canal system. It is calculated that only 2 to 3% of the eroded material is removed in solution.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 49 (1978), S. 147-159 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Experimental etching with hydrofluoric acid indicated that silica deposition occurs in a recognizable pattern in common sponge microscleres. The postdepositional alteration of these spicules has previously been generally unrecognized or misinterpreted in the literature. Early stages of postdepositional etching of sponge spicules were observed in the acid insoluble fraction of sediments from the West Atlantic barrier reef near Carrie Bow Cay, Belize. Preliminary data on silica distribution in the Belize barrier reef show that concentrations in fine sediment (〈0.25 mm) increase landward of the main reef tract. Sponge spicules are the main component of particulate silica in sediments of the reef and fore-reef where sponge populations abound, whereas grains prevail in the back-reef lagoon deposits. Recycling of locally dissolved silica appears to be important for the growth of many off-shore reef sponges.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Protein S-100 – Kinderherzchirurgie – kardiopulmonaler Bypass – Neugeborene – Kleinkinder ; Key words protein – S-100 – pediatric cardiac surgery – cardiopulmonary bypass – newborn, infants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The use of a biochemical marker for the early identification of cerebral injury associated with the corrective surgery of congential heart disease could possibly be of great diagnostic and prognostic value. S-100, a specific glia brain cell protein, may be released into serum following brain cell damage. The aim of this study was to investigate the levels of this biochemical marker in infants before and after corrective cardiac surgery by means of cardiopulmonary bypass (CPB). 42 newborns and infants were enrolled in this study. Blood samples were collected just before and immediately after CPB, and then again 2, 24, and 48 h postoperatively. The S-100 protein serum concentrations were analyzed using a commercially-available radioimmune kit. Peak values of S-100 were found immediately after surgery and during the first 2 h postoperatively, decreasing thereafter on the 2nd postoperative day to preoperative values (p 〈0.001). Newborn showed higher peak values (0,36 μg/l) than infants (0,95 μg/l). Newborns also had higher preoperative S-100-values than infants. A significant correlation was found between the peak values of S-100 and the age of the studied infants (r =–0,74; p 〈0.0001), and the minimal rectal temperature during CPB (r =–0,67; p = 0,0004). In conclusion: elevated S-100 serum values after cardiac surgery may provide information on ostensibly incurred cerebral injury. Neonates with cyanotic congenital heart disease showed significantly higher levels of Serum S-100 protein than older infants undergoing corrective cardiac surgery beyond the neonatal period. Follow-up studies are necessary to evaluate the significant prognostic value of this biochemical marker in the brain.
    Notes: Zusammenfassung Die Früherkennung und Prävention von zerebralen Schäden, die im Zusammenhang mit den herzchirurgischen Korrekturoperationen angeborener Herzfehler mit Hilfe des kardiopulmonalen Bypasses (CPB) im Neugeborenen- und Kleinkindesalter auftreten, ist von besonderer prognostischer und therapeutischer Bedeutung. Wir untersuchen daher prospektiv die Kinetik der Serumkonzentration von S-100, einem glia- und schwannzellspezifischen Protein, bei Kindern vor und nach Korreturoperationen mit Hilfe des CPB. Methoden: Es wurden bei 42 Kindern (16 Neugeborene und 26 Kleinkinder) intra- und postoperativ Blutproben entnommen und mit Hilfe eines kommerziell erhältlichen Radioimmunassays (Sangtec Mediacal AB, Bromma, Schweden) die S-100-Konzentration im Serum bestimmt. Bei allen Kindern wurde die Korrekturoperation mit Hilfe des full-flow-CPB in tiefer bis moderater Hypothermie durchgeführt. Ergebnisse: Bei allen Patienten fanden sich signifikant erhöhte Werte (p = 0,001) während der ersten 24 postoperativen Stunden, die sich jedoch innerhalb 72 Stunden den präopertiv bestimmten Werten anglichen. Bei den Neugeborenen wurden höhere Maximalwerte bestimmt (3,6μg/l) als bei den Kleinkindern (0,95 μg/l), sie wiesen auch höhere präoperative Werte auf. Es zeigte sich eine negative Korrelation zwischen dem maximalen S-100-Wert und dem Alter (r =–0,74; p 〈0,0001), dem Gewicht (r =–0,72; p = 0,002) und der minimalen rektalen Temperatur (r =–0,67; P = 0,0004) der Kinder während CPB. Schlußfolgerung: Der Nachweis von S-100-Serum und somit das Übertreten von S-100 aus dem Zytoplasma der Astrozyten im Blut kann möglicherweise ein Zeichen für auftretende zerebrale Schäden sein. S-100 könnte daher als ein früh-biochemischer Marker genutzt werden. Beeinflussende Faktoren der S-100-Serum-Konzentration sind Alter, Körpergewicht, Länge des kardiopulmonalen Bypasses und Grad der Hypothermie.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-0975
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.
    Type of Medium: Electronic Resource
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