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  • Life and Medical Sciences  (2)
  • Acoustics  (1)
  • Bloom timing  (1)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 149 (1991), S. 9-17 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Although the precise intracellular function(s) of the polyamines remain incompletely defined, a myraid of evidence now shows that the polyamines must accumulate or be maintained at a specific intracellular concentration in order for all mammalian cells to grow or divide. The initial step in polyamine biosynthesis normally involves the decarboxylation of ornithine by the enzyme ornithine decaboxylase (ODCase E.C. 4.1.1.17) to yield putrescine. Increases in the steady-state level of intracellular ornithine have been reported to markedly alter the accumulation of the polyamines following stimulation of Reuber H35 Hepatoma cells with 12-O-tetradecanoylphorbol-β-acetate (TPA) in the presence of serum (Wu and Byus:(Biochem. Biophys. Acta 804:89-99, 1984)) Wu et al.: (Cancer Res. 41:3384-3391, 1981). We wished to determine whether or not incubation of H35 hepatoma cells with exogenous ornithine would result in a stimulation of DNA synthesis following treatment with the mitogens TPA and insulin. For these studies, H35 cells were maintained under serum-free conditions for 2-3 days in order to obtain synchronous cultures suitable for analysis of the level of DNA synthesis. Cultures treated in this manner were highly viable, maintained similar growth rates, and possessed the equivalent levels of intracellular ornithine and polyamines as the serum-containing cultures. Arginine levels, however, were approximately twofold higher following culture under serum-restricted conditions for 3 days. The addition of exogenous ornithine (0.5 mM) was accompanied by a 4-5-fold increase in intracellular steady-state ornithine levels and by a 6-8-fold increase in the presence of TPA and ornithine. In a manner identical to the serum-containing cultures (Wu and Byus (1984)) the addition of TPA and exogenous ornithine to the serum-free cells caused a dose-dependent increase in intracellular putrescine (up to 5-fold) and a concomitant decrease in ODC activity in comparison to stimulation with TPA alone. The addition of TPA led to a 3-5-fold increase in the incorporation of tritiated thymidine into DNA. In the presence of exogenous ornithine, TPA-induced DNA synthesis was further stimulated more than twofold in a dose-dependent manner. Insulin (10-10-10-8 M) proved to be more efficacious as a mitogen in the H35 cells and led to greater stimulation of DNA synthesis than TPA. Insulin alone also resulted in a higher steady-state level of ornithine and putrescine in comparison with TPA alone. However, ornithine addition to the culture medium was not accompanied by any further increase in the insulin-mediated elevation in DNA synthesis. The data is discussed in relation to the selective ability of mitogens to alter the flux through extracellular and intracellular pools of ornithine as required to supply sufficient polyamines to support maximal rates of DNA synthesis. The results furthers support the suggestion that the high levels of intracellular putrescine observed following TPA + ornithine might enhance any of a number of the specific or unique transductive events employed by TPA, in comparison with insulin, which lead to the synthesis of DNA.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 457-471 
    ISSN: 0730-2312
    Keywords: coated vesicles ; acetylcholine receptors ; AP180 ; myotube ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Monoclonal antibodies were generated to vesicular membranes of clathrin coated vesicles enriched for acetylcholinesterase (AChE). One of these, C172, recognizes vesicles which accumulate in muscle cells around nuclei associated with acetylcholine receptor AChR clusters. Immunoblots of muscle extracts and brain purified clathrin coated vesicles show that C172 recognizes a 100 kd band in muscle, but a 180 kd band in brain. Western blots of purified AP180 protein stained with the two antibodies AP180.1 and C172 displayed the same staining pattern. Tryptic digests probed with peptide antibodies (PS26 and PS27) generated to known sequences of AP180 were used to map the epitope for C172 within the brain AP180 sequence. On immunoblots of digested AP180, all AP180 antibodies and C172 recognized a 100 kd tryptic fragment, however only C172 recognized a smaller 60 kd. Our results suggest that the C172 epitope is located within amino acids 305-598 of the AP180 sequence. Confocal fluorescence microscopy of myoblasts and myotubes stained with the C172 antibody gives a punctate immunofluorescence pattern. Myoblasts stained with C172 revealed a polarized distribution of vesicles distinct from that observed when cells are stained with γ adaptin antibody which is known to localize to trans Golgi network. Myotubes stained with C172 antibody reveal a linear array of vesicular staining. Quantitative analysis of C172 reactive vesicles revealed a significant increase in number of vesicles present around the nuclei associated with the acetylcholine receptor clusters. These vesicles did not colocalize with the Golgi cisternae. These results indicate that a protein with homology to the neuron-specific coated vesicle protein AP180, is present in muscle cells associated with vesicles showing significant concentration around postsynaptic nuclei present in close proximity to AChR clusters. J. Cell. Biochem. 68:457-471, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
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  • 3
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Continental Shelf Research 102 (2015): 47-61, doi:10.1016/j.csr.2015.04.005.
    Description: The spring phytoplankton bloom on the US Northeast Continental Shelf is a feature of the ecosystem production cycle that varies annually in timing, spatial extent, and magnitude. To quantify this variability, we analyzed remotely-sensed ocean color data at two spatial scales, one based on ecologically defined sub-units of the ecosystem (production units) and the other on a regular grid (0.5°). Five units were defined: Gulf of Maine East and West, Georges Bank, and Middle Atlantic Bight North and South. The units averaged 47×103 km2 in size. The initiation and termination of the spring bloom were determined using change-point analysis with constraints on what was identified as a bloom based on climatological bloom patterns. A discrete spring bloom was detected in most years over much of the western Gulf of Maine production unit. However, bloom frequency declined in the eastern Gulf of Maine and transitioned to frequencies as low as 50% along the southern flank of the Georges Bank production unit. Detectable spring blooms were episodic in the Middle Atlantic Bight production units. In the western Gulf of Maine, bloom duration was inversely related to bloom start day; thus, early blooms tended to be longer lasting and larger magnitude blooms. We view this as a phenological mismatch between bloom timing and the “top-down” grazing pressure that terminates a bloom. Estimates of secondary production were available from plankton surveys that provided spring indices of zooplankton biovolume. Winter chlorophyll biomass had little effect on spring zooplankton biovolume, whereas spring chlorophyll biomass had mixed effects on biovolume. There was evidence of a “bottom up” response seen on Georges Bank where spring zooplankton biovolume was positively correlated with the concentration of chlorophyll. However, in the western Gulf of Maine, biovolume was uncorrelated with chlorophyll concentration, but was positively correlated with bloom start and negatively correlated with magnitude. This observation is consistent with both a “top-down” mechanism of control of the bloom and a “bottom-up” effect of bloom timing on zooplankton grazing. Our inability to form a consistent model of these relationships across adjacent systems underscores the need for further research.
    Keywords: Spring bloom ; US Northeast Shelf ; Zooplankton biomass ; Bloom timing ; Climate
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Format: application/msword
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  • 4
    Publication Date: 2022-10-26
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Capotondi, A., Jacox, M., Bowler, C., Kavanaugh, M., Lehodey, P., Barrie, D., Brodie, S., Chaffron, S., Cheng, W., Dias, D. F., Eveillard, D., Guidi, L., Iudicone, D., Lovenduski, N. S., Nye, J. A., Ortiz, I., Pirhalla, D., Buil, M. P., Saba, V., Sheridan, S., Siedlecki, S., Subramanian, A., de Vargas, C., Di Lorenzo, E., Doney, S. C., Hermann, A. J., Joyce, T., Merrifield, M., Miller, A. J., Not, F., & Pesant, S. Observational needs supporting marine ecosystems modeling and forecasting: from the global ocean to regional and coastal systems. Frontiers in Marine Science, 6, (2019): 623, doi:10.3389/fmars.2019.00623.
    Description: Many coastal areas host rich marine ecosystems and are also centers of economic activities, including fishing, shipping and recreation. Due to the socioeconomic and ecological importance of these areas, predicting relevant indicators of the ecosystem state on sub-seasonal to interannual timescales is gaining increasing attention. Depending on the application, forecasts may be sought for variables and indicators spanning physics (e.g., sea level, temperature, currents), chemistry (e.g., nutrients, oxygen, pH), and biology (from viruses to top predators). Many components of the marine ecosystem are known to be influenced by leading modes of climate variability, which provide a physical basis for predictability. However, prediction capabilities remain limited by the lack of a clear understanding of the physical and biological processes involved, as well as by insufficient observations for forecast initialization and verification. The situation is further complicated by the influence of climate change on ocean conditions along coastal areas, including sea level rise, increased stratification, and shoaling of oxygen minimum zones. Observations are thus vital to all aspects of marine forecasting: statistical and/or dynamical model development, forecast initialization, and forecast validation, each of which has different observational requirements, which may be also specific to the study region. Here, we use examples from United States (U.S.) coastal applications to identify and describe the key requirements for an observational network that is needed to facilitate improved process understanding, as well as for sustaining operational ecosystem forecasting. We also describe new holistic observational approaches, e.g., approaches based on acoustics, inspired by Tara Oceans or by landscape ecology, which have the potential to support and expand ecosystem modeling and forecasting activities by bridging global and local observations.
    Description: This study was supported by the NOAA’s Climate Program Office’s Modeling, Analysis, Predictions, and Projections (MAPP) Program through grants NA17OAR4310106, NA17OAR4310104, NA17OAR4310108, NA17OAR4310109, NA17OAR4310110, NA17OAR4310111, NA17OAR4310112, and NA17OAR4310113. This manuscript is a product of the NOAA/MAPP Marine Prediction Task Force. The Tara Oceans consortium acknowledges support from the CNRS Research Federation FR2022 Global Ocean Systems Ecology and Evolution, and OCEANOMICS (grant agreement ‘Investissement d’Avenir’ ANR-11-BTBR-0008). This is article number 95 of the Tara Oceans consortium. MK and SD acknowledge support from NASA grant NNX14AP62A “National Marine Sanctuaries as Sentinel Sites for a Demonstration Marine Biodiversity Observation Network (MBON)” funded under the National Ocean Partnership Program (NOPP RFP NOAA-NOS-IOOS-2014-2003803 in partnership between NOAA, BOEM, and NASA), and the NOAA Integrated Ocean Observing System (IOOS) Program Office. WC, IO, and AH acknowledge partial support from the Joint Institute for the Study of the Atmosphere and Ocean (JISAO) under NOAA Cooperative Agreement NA15OAR4320063, Contribution No. 2019-1029. This study received support from the European H2020 International Cooperation project MESOPP (Mesopelagic Southern Ocean Prey and Predators), grant agreement no. 692173.
    Keywords: Marine ecosystems ; Modeling and forecasting ; Seascapes ; Genetics ; Acoustics
    Repository Name: Woods Hole Open Access Server
    Type: Article
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