ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effect of selected surfactants on the growth characteristics of Gymnodinium breve (1974)
    Springer
    Marine biology 28 (1974), S. 253-259 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth studies of Gymnodinium breve in nutrient enriched and unenriched medium showed that anionic surfactants have the most deleterious effects on initial response, growth rate, and maximum cell numbers as compared with cationic and non-ionics. Degradation rates were determined, and the surfactant with the most favorable rate (C12 alkyl-benzene sulfonate) was further tested. The growth constant, K e , and maximum cell number, N max , decreased with increasing amount of surfactant added to G. breve cultures (enriched sea-water media); a minimum was observed at 12.5 ppb. Above this concentration the values of K e and N max increased to approach control values. This profile was ascribed to the formation of surfactant micelles that are ineffective. The surfactant produced mortality of G. breve (90% mortality versus 12% in untreated samples) in natural red-tide samples, but other algae and zooplankton were undisturbed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388492
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effect of temperature on the proliferation of Gymnodinium breve and Gomphosphaeria aponina (1977)
    Springer
    Marine biology 41 (1977), S. 71-77 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of temperature on the growth and proliferation of two marine microorganisms, the toxigenic dinoflagellate Gymnodinium breve, and a potential bio-control organism, the blue-green alga Gomphosphaeria aponina, was determined by culturing the organisms in thermal gradients established by heating and cooling the opposite ends of an aluminum bar that had been adapted to hold culture tubes. Gradients were linear and stable for the duration of each trial. There was no relationship between variations in light and growth of the organisms. Gymnodinium breve showed optimum growth at 22°C, and proliferated over a range of temperatures (17° to 30°C). Below 17°C cultures of G. breve declined in growth, and at 4°C the organisms died within 5 h. Above 31°C there was rapid decline in viability of cells, and at 33.5°C the organism died within 24 h. Gomphosphaeria aponina showed optimum growth between 24° and 29°C, with a maximum at 27°C. Growth at temperatures greater than 31°C was minimal, but the organism survived. Limitation may be due to repression of the bio-synthesis of an iron-transport compound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00390583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Canonical variables and geodesic fields for the calculus of variations of multiple integrals in parametric form (1968)
    Springer
    Mathematische Zeitschrift 104 (1968), S. 16-27 
    Details
    ISSN: 1432-1823
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01114915
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Comparisons of the feeding activity and diets of male and female cunners Tautogolabrus adspersus (Pisces: Labridae) (1984)
    Springer
    Marine biology 84 (1984), S. 7-11 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The diel distribution of feeding activity during the spawning season was compared for territorial male and female cunners Tautogolabrus adspersus in Conception Bay, Newfoundland, Canada between June and August, 1978. Territorial males feed significantly less often than females and concentrate their feeding activities in the morning, whereas females feed as frequently in the afternoon as in the morning. Based on the contents of alimentary tracts, territorial males, non-territorial males, and females have different diets. Since these three groups share the same habitat, the observed dietary differences probably reflect differences in their foraging behaviour. The relevance of these findings to the concept of ‘time minimizer’ and ‘energy maximizer’ is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394521
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A tetraethylammonium-insensitive inward rectifier K+ channel in müller cells of the turtle (Pseudemys scripta elegans) retina (1994)
    Springer
    The journal of membrane biology 141 (1994), S. 239-245 
    Details
    ISSN: 1432-1424
    Keywords: Retina ; Glial cell ; Potassium channel ; Tetraethylammonium ; Patch clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ion channels present in isolated glial (Müller) cells from the retina of the turtle (Pseudemys scripta elegans) were studied with the patch clamp technique. The predominant conductance in these cells was due to an inward rectifying potassium current. The whole-cell conductance of the inward rectifier was 20.2±1.9 nS (n = 7 cells) in a standard extracellular saline solution (3 mm extracellular potassium). This conductance was dependent on the extracellular potassium concentration, with a 2.88-fold change in conductance per tenfold shift in concentration. The relative permeability sequence to potassium of the inward rectifier was found to be: potassium (1.0) 〉 rubidium (0.7) 〉 ammonium (0.2) 〉 lithium (0.1) = sodium (0.1), which corresponded to the Eisenman sequence IV or V for a strongfield-strength potassium binding site on the channel. The single channel conductance measured in cell-attached patches with potassium chloride (150 mm) in the pipette was 68.5 ± 6.0 pS (n = 3 patches). The inward rectifier current was not blocked by extracellular tetraethylammonium (TEA+, 20 mm), but was blocked by extracellular barium (5 mm) or cesium (5 mm). The TEA+ insensitivity of the inward rectifier potassium channel in Müller cells is unusual, given that this type of channel in most excitable cells is sensitive to micromolar concentrations of this compound, and may be a characteristic of inward rectifier potassium channels that are primarily involved with extracellular potassium regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Human macrophages contain a stretch-sensitive potassium channel that is activated by adherence and cytokines (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 305-315 
    Details
    ISSN: 1432-1424
    Keywords: Potassium channel ; Patch clamp ; Cyto-skeleton ; Cytokine ; Mechanosensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A variety of stimuli, including cytokines and adhesion to surfaces and matrix proteins, can regulate macrophage function, in part through changes in Ca2+-dependent second messengers. While fluctuation in in-tracellular Ca2+ is an important modulator of cellular activation, little attention has been paid to the roles of other ions whose cytoplasmic concentrations can be rapidly regulated by ion channels. To examine the role of ion channels in macrophage function, we undertook patch clamp studies of human culture-derived macrophages grown under serum-free conditions. The major ionic current in these cells was carried by an outwardly rectifying K+ channel, which had a single-channel conductance of 229 pS in symmetrical K+-rich solution and macroscopic whole-cell conductance of 9.8 nS. These channels opened infrequently in resting cells but were activated immediately by (i) adhesion of mobile cells onto a substrate, (ii) stretch applied to isolated membrane patches in Ca2+-free buffers, (iii) intracellular Ca2+ (EC50 of 0.4 μm), and (iv) the cytokine IL-2. Furthermore, barium and 4-aminopyridine, blockers of this channel, altered the organization and structure of the cytoskeletal proteins actin, tubulin and vimentin. These cytoskeletal changes were associated with reversible alteration to the morphology of the cells. Thus, we have identified an outwardly rectifying K+ channel that appeared to be involved in cytokine and adherence-mediated macrophage activation, and in the maintenance of cytoskeletal integrity and cell shape.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234528
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Paramylon synthesis by Euglena gracilis photoheterotrophically grown under low O2 pressure (1981)
    Springer
    Planta 153 (1981), S. 6-13 
    Details
    ISSN: 1432-2048
    Keywords: Aerophily (micro-) ; Chloroplasts ; Euglena ; Mitochondria ; Paramylon synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Special culture conditions for Euglena gracilis Z and ZR are described. They induce interactions between the chloroplast and mitochondrial metabolisms leading to paramylon synthesis. When grown in continuous light under pure nitrogen and in the presence of lactate as the sole carbon source, sugar synthesis occurs during the first 24 h of culture with the participation of both mitochondria (using lactate) and of chloroplasts (fixing CO2 from lactate decarboxylation). The activities of ribulose bisphosphate carboxylase, phosphoenolpyruvate carboxylase, and phosphoenolpyruvate carboxykinase are very high and mitochondria and chloroplasts develop then a common network of vesicles in which paramylon grains can be seen. Electron micrographs demonstrate membrane continuity between the two types of organelles. Occasionally the mitochondrial matrix and the chloroplast stroma are separated by only a unit membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Targeting of oleosins to the oil bodies of oilseed rape (Brassica napus L.) (1993)
    Springer
    Planta 189 (1993), S. 24-29 
    Details
    ISSN: 1432-2048
    Keywords: Brassica (protein targeting) ; Oil body ; Oleosin (in-vitro translation) ; Protein targeting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Oleosins of Brassica napus L. (oilseed rape) synthesized by in-vitro translation were found to be very efficiently targeted to microsomal membranes but only poorly translocated to oil bodies or emulsified oil. The use of other bilayer membranes as controls showed that this interaction was specific. The rate of oleosin synthesis in the presence of microsomes was enhanced about threefold, indicative of the involvement of the signal-recognition particle in the targeting process. There is no evidence for the cleavage of the protein during targeting and the protein sequence reveals no consensus cleavage site for the signal peptide. Protection experiments using Proteinase K revealed that about 6 kDa of the protein is exposed on the cytoplasmic side of the ER but the remainder is protected. Carbonate (pH 11) washing of microsomal membranes after in-vitro translation confirmed that oleosins have a domain which remains inserted in the ER rather than the protein being transported completely into the lumen of the ER. These results indicate that oleosins are transported via the ER prior to their accumulation on oil bodies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00201339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The response of Gymnodinium breve to municipal waste materials (1974)
    Springer
    Marine biology 24 (1974), S. 223-228 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The response of the unarmored dinoflagellate Gymnodinium breve, which is the causative organism in catastrophic fish kills along the Florida Gulf coast, to enrichment with selected inorganic nutrients, municipal waste materials, and various detergent components has been determined. The biostimulatory effects of the various enrichments were determined by a modification of the Provisional Algal Assay Procedure of the Joint Industry/Government Task Force on Eutrophication. Inorganic nutrients (orthophosphate, nitrate, and ammonia) were added individually and in combination, and the results were compared to equivalent enrichments with the effluent from a secondary sewage-treatment plant. The maximum cell population, Nmax, attained could be increased 3-fold by the sew-age-treatment plant effluent or by the equivalent combination of inorganic nutrients; individually, however, the inorganic nutrients had no pronounced effect on maximum cell population, Nmax (except for a 30% increase produced by slight orthophosphate enrichment). The results of these studies indiccate that, at concentrations of orthophosphate typical of Florida coastal waters (ca. 0.10 ppm), the growth-promoting potential (as reflected by Nmax) of the medium was a linear function of the ammonia-nitrogen concentration (0.01 to 0.11 ppm). The sewage-treatment plant effluent was presumably low in detergent phosphate, having been obtained from a treatment plant some 6 months after the enactment of a ban on phosphate-containing detergents. Additions of orthophosphate or detergent-phosphate to the treatment-plant effluent did not significantly increase the observed biostimulatory effect of the waste material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391897
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The background primal sketch: An approach for tracking moving objects (1992)
    Springer
    Machine vision and applications 5 (1992), S. 17-34 
    Details
    ISSN: 1432-1769
    Keywords: active contour ; motion tracking ; moving edges ; primal sketch ; robust statistics ; snakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper we present an algorithm that integrates spatial and temporal information for the tracking of moving nonrigid objects. In addition, we obtain outlines of the moving objects. Three basic ingredients are employed in the proposed algorithm, namely, the background primal sketch, the threshold, and outlier maps. The background primal sketch is an edge map of the background without moving objects. If the background primal sketch is known, then edges of moving objects can be determined by comparing the edge map of the input image with the background primal sketch. A moving edge point is modeled as an outlier, that is, a pixel with an edge value differing from the background edge value in the background primal sketch by an amount larger than the threshold in the threshold map at the same physical location. The map that contains all the outliers is called the outlier map. In this paper we present techniques based on robust statistics for determining the background primal sketch, the threshold, and outlier maps. In an ideal situation the outlier map would contain the complete outlines of the moving objects. In practice, the outliers do not form closed contours. The final step of the algorithm employs an edge-guided morphological approach to generate closed outlines of the moving objects. The proposed approach has been tested on sequences of moving human blood cells (neutrophil) as well as of human body motion with encouraging results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01213527
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...