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
  • Springer  (119)
  • American Physical Society (APS)
  • American Meteorological Society (AMS)
  • 1995-1999  (52)
  • 1980-1984  (67)
Collection
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 52 (1996), S. 757-761 
    ISSN: 1420-9071
    Keywords: Vasculogenesis ; angiogenesis ; muscle ; embryonic ; metabolites ; fibroblast growth factor (FGF) ; chorioallantoic membrane (CAM)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Normal and pathological formation of blood vessels is of considerable interest both in terms of basic scientific processes and clinical applications. Angiogenic events in the adult are likely to represent persistence of developmental mechanisms, and embryos are therefore a suitable experimental model for these processes. Among embryonic tissues, muscle is particularly appropriate for investigation, since it is highly vascularised from early stages. There are a number of competing explanations of how this process is controlled. Bioassays offer advantages over conventional molecular localisation techniques, in that they reveal the presence of active processed forms of the molecules under study, rather than non-processed forms, or non-translated meassages. Using these techniques, we report here that embryonic chick muscle, taken from the stages at which blood vessels are forming, produces an angiogenic activity on the chick chorioallantoic membrane (CAM), and transforms NR6 cells in soft agar. Basic fibroblast growth factor (bFGF) is shown to be angiogenic on the CAM in the same way, and also transforms NR6 cells (NR6 cells lack functional epidermal growth factor/transforming growth factor-a receptors, and are believed to respond only to bFGF in this way). Anti-bFGF removes the transforming activity of the embryonic muscle. We conclude that this represents evidence that embryonic chick muscle is producing an FGF-like molecule which is capable of acting as an angiogenic agent at the appropriate times in development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The RT1.C region has recently been defined genetically as a third region of the rat major histocompatibility system, RT1, and has been shown to code for cell-surface antigens with restricted tissue distribution (present on lymphocytes and absent from red blood cells and liver) and for target antigens of unrestricted cytotoxic T lymphocytes. Immunoprecipitation with C-antigen-specific alioantisera and SDS-PAGE analysis, reveal that C-region products are glycoproteins composed of molecules of 40 500–43 000 and 12 500 molecular weight, respectively. Thus, the RT1.B region, which codes for class II molecules, is flanked by RT1 regions which determine class I molecules (as defined biochemically), which are either expressed ubiquitously (RT1.A antigens) or in a restricted manner (RT1.C products). The homology to H-2Qa antigens is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Artificial intelligence review 9 (1995), S. 129-146 
    ISSN: 1573-7462
    Keywords: natural language ; multimedia ; human-computer interaction ; communication modalities ; dialogue ; generation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In the late Eighties the Natural Language Processing community began appreciating the role of multimodality in interactive systems. Intelligent multimodal systems are systems that integrate natural language (generally so far keyboard-based input, shortly also voice) with other media such as gestures in input or graphics in output. The perspective of what can be called visible interactive communication is discussed and considered as a possible new modality of natural language, after the spoken and the written ones. This should not be confused with the type of hypermedia that are now being developed. There, basically, the interface space is finite, even if one dimension may be added. Here the infinite creativity of human language is potentially preserved as the fundamental communication instrument.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experiments in fluids 2 (1984), S. 89-93 
    ISSN: 1432-1114
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A laser doppler anemometer (LDA) was used to measure local dispersion coefficients of particles in turbulent flow. The experimental set-up is described along with the data acquisition equipment and processing procedures. Results for 5 μ particles dispersing from a point source in pipe flow are shown. A second estimate for the diffusivity was obtained from mean square dispersion measurements.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 645-646 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A cold working steel was coated both with high temperature CVD (TiN) and moderate temperature CVD (Ti[C,N]). AES depth profiles show a significant difference at the interface, where a thin oxide layer remains detectable at deposition temperatures of 750 °C. It could be shown that an impedance signal at a frequency of 13 MHz is well suited to detect the early stages of the growth of a CVD coating.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 42 (1996), S. 352-353 
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 41 (1995), S. 612-615 
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract G and C-chromosome banding techniques have been used to compare the structure of the karyotype in a variety of colubrid and boid snakes. The comparison of G-band patterns indicates that while some band sequences have been conserved, either as whole chromosomes or entire arms, there is also evidence of considerable rearrangement especially in the smaller chromosomes. In the colubrid Elaphe subocularis there is also evidence that there has been a relocation of the centromere on chromosome 2 without any accompanying inversion in the sequence of G-bands. Finally, G-banding has facilitated the demonstration of a simple pericentric inversion distinguishing the Z and W chromosomes in Acrantophis dumereli. This represents the first report of differentiated sex chromosomes in a boid snake. The combined banding data thus indicates that snake chromosomes are certainly not lacking in variability. The use of C-banding to detect constitutive heterochromatin has confirmed that in some boids and colubrids macrochromosomes have been derived from microchromosomes by the additions of heterochromatin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 74 (1982), S. 85-93 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and X-Ray microanalytical aspects of primary biliary cirrhosis were analysed and compared to those of normal liver. Electron microscopic studies showed a significant increase of dense lipofuscin-like granules in PBC compared to the hepatocytes of normal liver (665%). These granules (0.3–2.7 μm in diameter) were formed by the association of primary lysosomes and lipid droplets. X-Ray microanalysis of these structures showed the presence of Calcium, Phosphorus, Potassium, Chlorine, Sulphur, Aluminium and Copper. The coexistence of Sulphur with other mineral elements suggests the occurence of metalloproteins binding these elements. These findings provide evidence that intralysosomal sequestration of mineral elements, especially copper protects the hepatocytes from cytotoxic effects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-1939
    Keywords: Nitrogen isotope discrimination ; Cape floristic region ; Fynbos ; Strandveld ; Acacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study examines the impacts of woody, N2-fixing invasive Acacia spp. on the patterns of nutrient cycling in two invaded ecosystems of differing nutrient status in the Cape floristic region. Patterns of soil nutrient mineralization were measured by a field incubation method while the significance of the fixation process in altering nutrient cycling was assessed by the δ15N natural abundance technique. The results confirm earlier reports that invasion by woody shrubs results in organic matter and nutrient enrichment of surface soils of both ecosystems. However, patterns of nutrient availability (phosphorus and nitrogen) were not necessarily enhanced. In the more fertile strandveld both phosphorus and nitrogen (significant at P〈0.10) showed trends towards enhanced annual mineralization rates upon invasion, while in the low nutrient fynbos system only phosphorus followed this trend. It is unclear whether this differential response is a consequence of plant- or soil-derived feedbacks on the decomposition processes in each system. The δ15N values of the soils from the invaded sites of both ecosystems indicated a strong influence of the alien species on the soil nitrogen component. However, as with other studies of natural ecosystems, the contribution of nitrogen from fixation could not be readily quantified with the δ15N natural abundance method because of problems in selecting suitable non-N2-fixing reference plants. A technique of disrupting nodule structure and function, by fumigation with O2, to obtain the δ15N value of a non-N2-fixing speciment of the study species was tried and found to overcome some of the problems associated with the lack of suitable reference plants. With this technique it was possible to detect the almost total dependence of A. saligna on N2-fixation in the fynbos soils with their low nitrogen mineralization rates. In the strandveld ecosystem with much higher soil nitrogen release rates A. cyclops was only partly dependent on fixation (about half) for its nitrogen. The nutrient enrichment of both ecosystems and trends towards enhanced rates of nutrient mineralization could have profound implications on the long-term success of alien invader clearing operations and the restoration of the indigenous flora at these sites.
    Type of Medium: Electronic Resource
    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...