GLORIA

GEOMAR Library Ocean Research Information Access

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
    Schlagwort(e): Hochschulschrift
    Materialart: Online-Ressource
    Seiten: 1 Online-Ressource (142 Seiten = 31MB) , Illustrationen, Graphen
    Ausgabe: Online-Ausgabe 2023
    Sprache: Deutsch
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] The chemokine receptors that mediate HIV-1 entry in cultured cells vary in their tissue distribution. CCR5 is expressed in primary monocyte/macrophages, primary T cells, and granulocyte precursors2'4. CXCR4 is expressed in a broader range of tissues and cell types, including the brain and T cells1. ...
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1573-0417
    Schlagwort(e): transfer functions ; weighted-averagingpartial-least-squares ; summer temperatures ; surfacesediments ; modern training-sets ; Switzerland
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Diatom, chrysophyte cyst, benthic cladocera, planktonic cladocera, and chironomid assemblages were studied in the surface sediments of 68 small lakes along an altitudinal gradient from 300 to 2350 m in Switzerland. In addition, 43 environmental variables relating to the physical limnology, geography, catchment characteristics, climate, and water chemistry were recorded or measured for each lake. The explanatory power of each of these predictor variables for the different biological data-sets was estimated by a series of canonical correspondence analyses (CCA) and the statistical significance of each model was assessed by Monte Carlo permutation tests. A minimal set of environmental variables was found for each biological data-set by a forward-selection procedure within CCA. The unique, independent explanatory power of each set of environmental variables was estimated by a series of CCAs and partial CCAs. Inference models or transfer functions for mean summer (June, July, August) air temperature were developed for each biological data-set using weighted-averaging partial least squares or partial least squares. The final transfer functions, after data screening, have root mean squared errors of prediction, as assessed by leave-one-out cross-validation, of 1.37 °C (chironomids), 1.60 °C (benthic cladocera), 1.62 °C (diatoms), 1.77 °C (planktonic cladocera), and 2.23 °C (chrysophyte cysts).
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Journal of paleolimnology 19 (1998), S. 55-62 
    ISSN: 1573-0417
    Schlagwort(e): Cladocera ; Chironomidae ; subfossil remains ; lake level ; inshore/offshore sediments ; planktonic/littoral ratio
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Water level fluctuations affect the size of the pelagic zone relative to the size of littoral habitats, and thus may influence the relative abundance of remains from planktonic and littoral cladocerans in sediment. The application of this planktonic/littoral ratio for the reconstruction of past water level changes is discussed using examples of: (1) surficial profundal sediments from lakes of different water depths; (2) Holocene variation in a profundal sediment core; (3) horizontal variation in surficial sediments within a lake; and (4) long term variation in an inshore sediment core. The latter seemed to be the most promising application of this ratio. Maximum effects of water depth changes on the lake fauna are expected in the littoral zone. It is, however, difficult to read this effect directly from subfossil cladoceran and chironomid assemblages from inshore sediments as shown by a sediment profile from a site exposed to a long term decrease of water depth.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 1573-0417
    Schlagwort(e): transfer functions ; WA-PLS ; total phosphorus ; trophic state ; eutrophication ; surface sediments ; Switzerland ; diatoms ; cladocera ; chironomids ; chrysophytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Surface sediments from 68 small lakes in the Alps and 9 well-dated sediment core samples that cover a gradient of total phosphorus (TP) concentrations of 6 to 520 μg TP l-1 were studied for diatom, chrysophyte cyst, cladocera, and chironomid assemblages. Inference models for mean circulation log10 TP were developed for diatoms, chironomids, and benthic cladocera using weighted-averaging partial least squares. After screening for outliers, the final transfer functions have coefficients of determination (r2, as assessed by cross-validation, of 0.79 (diatoms), 0.68 (chironomids), and 0.49 (benthic cladocera). Planktonic cladocera and chrysophytes show very weak relationships to TP and no TP inference models were developed for these biota. Diatoms showed the best relationship with TP, whereas the other biota all have large secondary gradients, suggesting that variables other than TP have a strong influence on their composition and abundance. Comparison with other diatom – TP inference models shows that our model has high predictive power and a low root mean squared error of prediction, as assessed by cross-validation.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Monatshefte für Chemie 116 (1985), S. 569-580 
    ISSN: 1434-4475
    Schlagwort(e): Ternary alkaline earth and rare earth metal palladium arsenides, antimonides, and bismuthides ; Crystal structure ; Band structure ; Intermediate valency of Eu compounds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Fifteen compounds of compositionMPd2 Pn 2 (M = alkaline earth or rare earth metal,Pn = As, Sb, Bi) were prepared. TheirGuinier powder patterns show that the arsenides crystallize with the ThCr2Si2 type structure, the bismuthides with the closely related CaBe2Ge2 type structure. The antimonides most likely also have the CaBe2Ge2 structure as is demonstrated by a structure refinement of EuPd2Sb2 from single crystal X ray data (R = 0.039 for 366 independent structure factors and 15 variable parameters). The structure of SrPd2As2 (ThCr2Si2 type) was refined to a residual ofR = 0.020 for 182F values and 9 variables. EuPd2Sb2 is paramagnetic and a metallic conductor. A comparison of the cell volumes suggests intermediate valency for Eu in EuPd2As2. Chemical bonding and especially the reasons for the adoption of the ThCr2Si2 or CaBe2Ge2 type structures by these compounds are discussed. It is suggested that in going from the phosphides to the bismuthides the ThCr2Si2 structure is loosing and the CaBe2Ge2 structure is gaining stability due to decreasing Pd-Pd bonding and increasing Pd-pnictogen bonding. This trend is caused by the increasing size of the pnictogen component.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1573-5117
    Schlagwort(e): cladocera ; sediment analysis ; lake trophy ; bioindication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The cladoceran faunas from 13 northern German lakes (the Plön district) of different trophic levels were analysed using the bosminid and chydorid remains in the surficial sediment as an integrated sample of the total lake fauna. In the dimictic lakes, a shift occurred in the composition of planktonic Cladocera from Bosmina coregoni, including morphs with a mucro, to predominance of Chydorus sphaericus and Bosmina c. thersites as trophic state increased. In the benthic Cladocera (Chydoridae), there was a decrease in species diversity, in the percentages of phytophilous species and in the portion of species that are typical of ‘clear water lakes’, but there was an increase both in the number of mud dwellers and species that are typical of ‘polluted lakes’. No positive correlation was found between mean depth of the lakes and the planktonic/littoral ratio.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Hydrobiologia 103 (1983), S. 235-239 
    ISSN: 1573-5117
    Schlagwort(e): paleolimnology ; cladoceran analysis ; chironomid analysis ; successions ; lake development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the subfossil assemblages of chironomids and cladocerans significant changes were found during the late-glacial and postglacial development of a small, shallow North German lake. The successions observed were obviously not related to eutrophication but to factors such as climatic conditions and lake siltation. The absence of species of the subgenus Eubosmina during postglacial times as well as the predominance of Alonella species among the chydorids was due to the small dimensions of the water body.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Hydrobiologia 101 (1983), S. 247-254 
    ISSN: 1573-5117
    Schlagwort(e): Keratella cochlearis ; morphological variation ; cyclomorphosis ; Lauterborn cycle ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The existence of separated forms within the population of Keratella cochlearis (Gosse) from Lake Plußsee was demonstrated on the basis of a biometric analysis. The morphs cochlearis, hispida and tecta were definitely not connected by transitional forms. Micracantha and tecta were not links of a macracantha-micracantha-tecta-series. Hence, the general validity of Lauterborn-cycles is questioned. In this connection, the taxonomy of this species is also involved, because it is derived from the idea of phenotypic cycles in the sense of Lauterborn.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Hydrobiologia 104 (1983), S. 363-365 
    ISSN: 1573-5117
    Schlagwort(e): rotifers ; population dynamics ; predation ; competition ; species diversity ; Asplanchna ; Keratella
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Extremely high abundance of Asplanchna priodonta led to a decline in the population of the preferred food species, Keratella cochlearis and subsequently, to the extinction of the predator population. Kellicottia longispina was obviously favoured by the predatory losses of the Keratella. Thus, the interactions between Asplanchna and Keratella influenced the zooplankton community structure.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...