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
  • 1
    Keywords: Freshwater ecology. ; Marine ecology. ; Biotic communities. ; Population biology. ; Animal culture. ; Conservation biology. ; Ecology . ; Freshwater and Marine Ecology. ; Community and Population Ecology. ; Animal Science. ; Conservation Biology. ; Ecosystems.
    Description / Table of Contents: Introduction. The Lake Charr: Biology, Ecology, Distribution, and Management -- Distribution -- Paleoecology -- Ecological Diversity -- Genetic Diversity -- Habitat -- Movement Ecology and Behavior -- Life History and Population Dynamics -- Trophic Ecology -- Reproduction -- Contaminants and Ecotoxicology -- A General, Life History Based Model for Sustainable Exploitation of Lake Charr across their Range -- Terminology Issues in Lake Charr Early Development.
    Abstract: The lake charr Salvelinus namaycush is a ubiquitous member of cold-water lake ecosystems in previously glaciated regions of northern continental U.S., Alaska, and Canada that often support important commercial, recreational, and subsistence fisheries. The lake charr differs from other charrs by its large size, longevity, iteroparity, top-predator specialization, reduced sexual dimorphism, prevalence of lacustrine spawning, and use of deepwater habitat. The species is remarkably variable in phenotype, physiology, and life history, some of which is reflected in its ecology and genetics, with as many as four morphs or ecotypes co-occurring in a single lake. The lake charr is often the top predator in these systems, but is highly adaptable trophically, and is frequently planktivorous in small lakes. The lake charr by their name highlights their common habitat, lakes both large and small, but often frequents rivers and occasionally moves into the Arctic Ocean. Movement and behaviour of lake charr are motivated by access to cool, well-oxygenated water, foraging opportunities, predator avoidance, and reproduction. Owing to their broad distribution and trophic level, the lake charr serves as a sentinel of anthropogenic change. This volume will provide an up-to-date summary of what is currently known about lake charr from distribution to genetics to physiology to ecology. The book provides a compilation and synthesis of available information on the lake charr, beginning with an updated distribution and a revised treatment of the paleoecology of the species. Understanding of ecological and genetic diversity and movement and behaviour of the species has advanced remarkably since the last major synthesis on the species over 40 years ago. Mid-sections of the book provide detailed accounts of the biology and life history of the species, and later sections are devoted to threats to conservation and fishery management practices used to ensure sustainability. A new standard lake charr-specific terminology is also presented. The book will be a valuable reference text for biologists around the world, ecologists, and fishery managers, and of interest to the angling public.
    Type of Medium: Online Resource
    Pages: XXXVII, 497 p. 107 illus., 71 illus. in color. , online resource.
    Edition: 1st ed. 2021.
    ISBN: 9783030622596
    Series Statement: Fish & Fisheries Series, 39
    DDC: 577.6
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6630-6632 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of the bottom shield on magnetoresistive (MR) head read-back performance was systematically studied by using a spin-stand tester and a magnetic force microscope with magnetoresistive sensitivity map (MSM) capability. Two groups of high density MR heads with identical design, processes and materials, except for their bottom shields, were tested. It was found that the higher the initial permeability of the shield, the smaller the PW50, the steeper the 50% height slope and the smaller the shoulder in the corresponding side of the isolated transition read-back pulse. The MSM images and analysis not only corroborated the spin stand results, but they also gave additional information about the isolated pulse shape and cross-track profile. The MSM was found to be a useful tool in studying the shield effects on isolated pulses as well as their impact on microtrack profiles. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 43 (1978), S. 4885-4887 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 46 (2003), S. 0 
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Mechanisms controlling microbial degradation of dissolved organic matter (DOM) in aquatic environments are poorly understood, although microbes are crucial to global nutrient cycling. Bacterial cell wall components may be one of the keys in understanding the presence of slowly degrading DOM in nature. We found that dominant components of bacterial cell walls (D-amino acids (D-AA), glucosamine (GluA) and diaminopimelic acid (DAPA)) comprised up to 11.4% of the dissolved organic nitrogen in 50 diverse rivers entering the Baltic Sea. Occurrence of DAPA, a characteristic component of Gram-negative (G−) bacteria, in the rivers suggests that G− bacteria rather than Gram-positive (G+) were the major source of the cell wall material. In laboratory studies, the degradation of whole bacterial cells, cell wall material and purified peptidoglycan was studied to characterize degradation of cell wall material by natural aquatic bacteria. Addition of whole killed G− and G+ bacteria to cultures of estuarine bacteria demonstrated fragmentation and loss of cell structure of the G+ bacteria, while the G− bacteria maintained an intact cell shape during the entire 69-day period. In another experiment, estuarine bacteria degraded 39–69% of GluA, D-AA and DAPA in added cell wall material of a representative G− bacterial species during 8 days, as compared to a 72–89% degradation of GluA, D-AA and DAPA in cell material of a G+ bacterial species. When cultures of estuarine bacteria were enriched with purified G− and G+ peptidoglycan (1 mg l−1), at least 49% (G−) and 58% (G+) of D-AA in the peptidoglycan was degraded. No major changes in GluA were obvious. Interpretation of the results was difficult as a portion of the purified peptidoglycan was of similar size to the bacteria and could not be differentiated from cells growing in the cultures. Addition of the purified peptidoglycan stimulated the bacterial growth, and after 6 days the cell density in the enriched cultures was 4-fold higher than in the controls. A regrowth of bacteria after addition of L-broth at 105 days caused a 50- to 75-fold increase in dissolved D-AA and GluA. Most of the D-AA and GluA were taken up during the following 10 days, indicating that cell wall constituents are dynamic compounds. Our results show that a variable portion of peptidoglycan in G− and G+ bacteria can be degraded by natural bacteria, and that peptidoglycan in G− bacteria is more resistant to bacterial attack than that in G+ bacteria. Thus, the presence of cell wall constituents in natural DOM may reflect the recalcitrant nature of especially G− peptidoglycan.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The correlation between the growth rate, rRNA concentration and number of rrna operons was studied in Alcaligenes sp. A2, Pseudomonas fluorescens R2f and Bacillus sp. B1 cells grown exponentially in liquid 1/10 strength tryptic soy broth (1/10 TSB) medium and grown to microcolony (mCFU) size on polycarbonate membrane filters floating on 1/10 TSB. The rRNA concentration was also determined in cells forming mCFUs after incubation on membranes of rhizosphere and bulk soil samples taken from a barley (Hordeum vulgare) microcosm experiment. A protocol for fluorescent in situ hybridization directly on polycarbonate membrane filters combined with confocal laser scanning microscopy and image analysis was used to measure the probing intensity from individual cells within the mCFUs. We found that cells forming mCFU on membranes had a rRNA concentration slightly higher than cells grown in fluid medium. Mean values of growth rates and rRNA concentration measured as a probing intensity per cell area were 0.31, 0.61 and 0.63 h−1 and 52, 63 and 146 units per cell area for Alcaligenes sp. A2, P. fluorescens R2f, and Bacillus sp. B1, respectively, when grown on membranes. The number of rrna operons carried by the three bacteria was determined to be between two to three, four and seven to nine. Alcaligenes sp. A2 which carried only two to three rrna operons had the lowest concentration of rRNA. Furthermore this organism had a lower growth rate compared to P. fluorescens R2f, and Bacillus sp. B1. Although P. fluorescens R2f and Bacillus sp. B1 had the same growth rate, Bacillus sp. B1 expressed a much higher rRNA concentration, which reflected well the high number of rrna operons carried by this bacterium. The mean probing intensity of mCFUs obtained after incubation of rhizosphere and bulk soil samples varied more than four-fold in both environments. The percentage of mCFU forming bacteria expressing a low concentration of rRNA was at least as high in the rhizosphere as in the bulk soil. The rationale behind carrying a high copy number of rrna operons and maintaining high concentrations of rRNA during growth is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Colonization at sugar beet root surfaces by seedling-inoculated biocontrol strain Pseudomonas fluorescens DR54 and native soil bacteria was followed over a period of 3 weeks using a combination of immunofluorescence (DR54-targeting specific antibody) and fluorescence in situ hybridization (rRNA-targeting Eubacteria EUB338 probe) techniques with confocal laser scanning microscopy. The dual staining protocol allowed cellular activity (ribosomal number) to be recorded in both single cells and microcolonies of strain DR54 during establishment on the root. After 2 days, the population density of strain DR54 reached a constant level at the root basis. From this time, however, high cellular activity was only found in few bacteria located as single cells, whereas all microcolony-forming cells occurring in aggregates were still active. In contrast, a low density of strain DR54 was observed at the root tip, but here many of the bacteria located as single cells were active. The native population of soil bacteria, comprising a diverse assembly of morphologically different forms and size classes, initiated colonization at the root basis only after 2 days of incubation. Hence the dual staining protocol allowed direct microscopic studies of early root colonization by both inoculant and native soil bacteria, including their differentiation into active and non-active cells and into single or microcolony-forming cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Highly specific polyclonal antibodies against two Pseudomonas fluorescens strains (DF57 and Ag1), which differed by approximately 10% of their utilizable substrates as tested in Biolog GN plates, were used for in situ labelling of bacterial cells colonizing barley roots grown in sterile soil. By using a confocal laser scanning microscope single bacteria of both strains could be detected on the roots. Seed-inoculated bacteria rapidly colonized the root surface (rhizoplane) by active migration; after 1 day the anterior part of the root was densely covered by bacteria occupying the crevices between epidermal root cells. As the roots became longer, this bacterial population in the rhizoplane formed long strings of closely associated cells. After 7 days, however, the rhizoplane population of string-forming cells was partially detached developing a patchy distribution along the root; a separate population of cells localized in the slime matrix (mucigel) surrounding the root was well developed at this time. Using two different fluorochromes attached to the antibodies, the two strains could be detected simultaneously in co-inoculation experiments. The recordings, however, gave no indications of competition between the two strains during root colonization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 12 (1994), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The unusual longevity of the Escherichia coli ompA transcript is determined by its 5′untranslated region (UTR), which functions In vivo as an mRNA stabilizer. Here we show that this 5′UTR can prolong the lifetime in E. coli of a variety of heterologous mRNAs to which it is Joined, either as a gene fusion or as an operon fusion. Statistical extrapolation suggests that it is quite likely that most E. coli mRNAs could be stabilized in this manner. We conclude that the ompA 5′ UTR impedes a major pathway for mRNA degradation in E. coli and that stabilization by fusion to this UTR does not require translational readthrough of the heterologous mRNA segment by ribosomes that initiate translation at the ompA ribosome-binding site. Additional experiments indicate that the E. coli ribonuclease whose action is slowed by the ompA 5′ UTR is not RNase III.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 413 (2001), S. 272-272 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Most of the world's cod (Gadus morhua) fisheries are now tightly regulated or closed altogether. Being able to link individual fish to their population of origin would assist enormously in policing regulations and in identifying poachers. Here we show that microsatellite genetic markers can be ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract. This paper describes fast and accurate calibration-free adaptive saccade control of a four-degrees-of-freedom binocular camera-head by means of Dynamic Cell Structures (DCS). The approach has been inspired by biology because primates face a similar problem and there is strong evidence that they have solved it in a similar way, i.e., by error feedback learning of an inverse model. Yet the emphasis of this article is not on detailed biological modeling but on how incremental growth of our artificial neural network model up to a prespecified precision results in very small networks suitable for real-time saccade control. Error-feedback-based training of this network proceeds in two phases. In the first phase we use a crude model of the cameras and the kinematics of the head to learn the topology of the input manifold together with a rough approximation of the control function off-line. In contrast to, for example, Kohonen-type adaptation rules, the distribution of neural units minimizes the control error and does not merely mimic the input probability density. In the second phase, the operating phase, the linear output units of the network continue to adapt on-line. Besides our TRC binocular camera-head we use a Datacube image processing system and a Stäubli R90 robot arm for automated training in the second phase. It will be demonstrated that the controller successfully corrects errors in the model and rapidly adapts to changing parameters.
    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...