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  • 1995-1999  (3)
  • 1965-1969  (7)
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  • 1
    Electronic Resource
    Electronic Resource
    Patterns of spiral tip motion in cardiac tissues (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 8 (1998), S. 137-148 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In support of the spiral wave theory of reentry, simulation studies and animal models have been utilized to show various patterns of spiral wave tip motion such as meandering and drifting. However, the demonstration of these or any other patterns in cardiac tissues have been limited. Whether such patterns of spiral tip motion are commonly observed in fibrillating cardiac tissues is unknown, and whether such patterns form the basis of ventricular tachycardia or fibrillation remain debatable. Using a computerized dynamic activation display, 108 episodes of atrial and ventricular tachycardia and fibrillation in isolated and intact canine cardiac tissues, as well as in vitro swine and myopathic human cardiac tissues, were analyzed for patterns of nonstationary, spiral wave tip motion. Among them, 46 episodes were from normal animal myocardium without pharmacological perturbations, 50 samples were from normal animal myocardium, either treated with drugs or had chemical ablation of the subendocardium, and 12 samples were from diseased human hearts. Among the total episodes, 11 of them had obvious nonstationary spiral tip motion with a life span of 〉2 cycles and with consecutive reentrant paths distinct from each other. Four patterns were observed: (1) meandering with an inward petal flower in 2; (2) meandering with outward petals in 5; (3) irregularly concentric in 3 (core moving about a common center); and (4) drift in 1 (linear core movement). The life span of a single nonstationary spiral wave lasted no more than 7 complete cycles with a mean of 4.6±4.3, and a median of 4.5 cycles in our samples. Conclusion: (1) Patently evident nonstationary spiral waves with long life spans were uncommon in our sample of mostly normal cardiac tissues, thus making a single meandering spiral wave an unlikely major mechanism of fibrillation in normal ventricular myocardium. (2) A tendency toward four patterns of nonstationary spiral tip motion was observed. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.166294
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  • 2
    Electronic Resource
    Electronic Resource
    Minimal Defined Media for Vegetative Growth of the Acrasian Polysphondylium pallidum WS-320 (1966)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Polysphondylium pallidum WS-320 grows indefinitely as vegetative amebae in a liquid medium where (a) substrates comprise sucrose, glycerol, acetate, lactate, citrate, and glutamate; (b) essential nutrients (riboflavin, lysine, glycine, and possibly several other amino acids that may be essential) are supplied. The growth thus supported (2 × 106 cells/ml) is more than doubled by provision of a mixture of crude fatty acids, an acid hydrolysate of casein supplemented with B vitamins, purines, pyrimidines, and fat-soluble antioxidants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1966.tb01888.x
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  • 3
    Electronic Resource
    Electronic Resource
    Tracer Experiments in Feeding Littoral Foraminifera (1966)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Tracer technic has proved to be an excellent tool in the study of predator-prey relationships among the foraminifera. More than fifty axenic species of protists including diatoms, dinoflagellates, chlorophytes, chrysophytes, cyanophytes, bacteria and yeasts were tested as potential food for Allogromia sp (NF), A. laticollaris, Am. monia beccarii, Quinqueloculina spp, Rosalina floridana, Anomalina sp, Elphidium sp, Spiroloculina hyalina, Globigerina bulloides, and Globorotalia truncatulinoides. Although many types of potential food are present in the environment, foraminifera select only certain organisms. The yeasts, cyanophytes, dinoflagellates, chrysophytes and most bacteria tested were not eaten. Selected species of diatoms, chlorophytes and bacteria were eaten in large quantity. Three additional factors affect feeding: the “age” of the food organism, the “age” of the foraminifer or its position in the life cycle, and the concentration of the food. Feeding by foraminifera on most food is erratic below a concentration of 103 organisms and is approximately directly proportional to concentration within a range of 103-106 organisms per 10 ml experimental tube. A natural bloom of Protelphidium tisburyensis was analyzed. A high concentration of 6 species of diatoms characterized the community. A “bloom”-feeder hypothesis for foraminiferal nutrition is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1966.tb01978.x
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  • 4
    Electronic Resource
    Electronic Resource
    Prolonged Culture of the Voracious Flagellate Peranema in Antioxidant-Containing Media (1966)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Peranema trichophorum remained vigorous at least a year in milk-lecithin media and 3 months in a nearly defined autoclavable biphasic agar medium fortified with the fat-soluble antioxidant butylated hydroxytoluene. The only undefined substance in the present “defined” medium is crude soybean lecithin; 0.001% lecithin suffices in the presence of a mixture of long-chain saturated and unsaturated fatty acids. Linoleic acid may be indispensable. Histidine is an absolute requirement as well as a favored substrate. Cholesterol, not ergosterol, satisfied the sterol requirement. Voracity is retained in these media as shown by engorgement on plastic latex particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1966.tb01877.x
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  • 5
    Electronic Resource
    Electronic Resource
    Cytological Observations on Two Planktonic Foraminifera, Globigerina bulloides d'Orbigny, 1826, and Globigerinoides ruber (d'Orbigny, 1839) Cushman, 1927 (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Globigerina bulloides and Globigerinoides ruber, two pelagic foraminifera from the North Atlantic, were fixed in modified Zenker or Bouin solutions directly after collection and studied cytochemically. They have two unusual organelles: a vesicular system and an organelle provisionally named a “cryptosome.” The vesicular system occurs chiefly in the newest formed chambers and consists of a pair of intertwined tubules with helical fine structure which terminate in a bouquet of approximately 20 vesicles or loops. The function of this system is unknown. The detailed morphology of the vesicular system is different in each species. The cryptosome is a structure which varies greatly in its morphology. It is better developed in G. bulloides than it is in G. ruber. At times a cryptosome may occupy up to 2/3 of the protoplasm of a chamber. In Himes-Moriber-stained preparations crypto-somes stain with naphthol yellow S and contain within them an azure A-Schiff staining spongy reticulum. Both of the pelagic foraminifera studied are heterokaryotic. Agamonts of G. ruber may have a graded series of nuclear sizes but those of G. bulloides typically have a single somatic nucleus. The zooxanthellae of G. ruber are similar to Symbiodinium microadriaticum and may collectively occupy almost 4/5 the volume of a chamber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03253.x
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  • 6
    Electronic Resource
    Electronic Resource
    Quantitative Studies on the Growth of Allogromia laticollaris (Foraminifera) (1969)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 16 (1969), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The growth and reproduction of Allogromia laticollaris was studied. More schizozoites were generally produced in mixtures of food organisms than on single algal foods. In the presence of moderate numbers of bacteria, cultures with Phaeodactylum tricornutum, Chlorococcum sp., Nannochloris sp., and an unidentified chlorophyte (BL-1), added singly, were also highly productive. Schizogony was the dominant asexual form of reproduction. Binary fission and cytotomy also occurred in bacterized otherwise unfed controls. 35S and 32P are convenient labels for measuring growth of A. laticollaris when introduced into the system in the range of 1 × 104 - 1 × 105 dpm/ml (32P specific activity ∼ 2.03 MCi/g; 35S specific activity ∼ 95 μCi/g). Small allogromiids grew faster than did larger ones. By means of the Taylor series modification of the classical least-squares method, a continuous life-cycle representation was calculated for A. laticollaris for the conditions of the experiment. Four points of cell volume growth were maxima for reproduction: 1.0 × 107μ per organism for curve I; 2.2 × 107μ3 and 1.2 × 107μ3 for curve II; and 6.7 × 107μ3 for curve III.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1969.tb02286.x
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  • 7
    Electronic Resource
    Electronic Resource
    Apparent Indispensability of Bacteria in Foraminiferan Nutrition (1969)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 16 (1969), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Bacteria were required for the sustained reproduction of 4 species of foraminifera in gnotobiotic culture. None of the species of algae tested, singly or in combination, supported continuous reproduction of the foraminifera in bacteria-free gnotobiotic culture. It is inferred that bacteria have some nutritional factor required by the foraminifera that is either unavailable or unavailable in sufficient quantity in an exclusively algal diet.Gnotobiotic clones of Quinqueloculina lata, Spiroloculina hyalina, Rosalina leei, and Allogromia laticollaris were established on bacteria + algae (usually 1 or 2 species). In balanced gnotobiotic cultures neither light nor foraminiferan density (organisms/ml) were limiting. As cultures aged, pH shifted and limited growth. When waste products were removed by washing, reproductive rates were higher.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1969.tb02303.x
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  • 8
    Electronic Resource
    Electronic Resource
    Algal Flagellate Symbiosis in the Foraminifer Archaias (1969)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 16 (1969), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A symbiotic alga from the foraminifer Archaias angulatus was isolated axenically. Algae from crushed hosts were coccoid and highly vacuolated; division stages within an envelope were common. Biflagellate motile piriform organisms predominated in newly transferred cultures and were gradually replaced by the coccoid, highly vacuolated stage. Incorporation of 14C label in intact Archaias was greatest for organisms fed and incubated in light. Starved symbiotized organisms incubated in the light incorporated ∼30% as much label as fed counterparts, There was no obvious difference in 45Ca incorporation between fed and starved organisms. Light significantly enhanced calcification. The Archaias symbiont infected Rosalina leei but not Quinqueloculina spp.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1969.tb02235.x
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  • 9
    Electronic Resource
    Electronic Resource
    TULP1 mutation in two extended Dominican kindreds with autosomal recessive Retinitis pigmentosa (1998)
    [s.l.] : Nature Publishing Group
    Nature genetics 18 (1998), S. 177-179 
    Details
    ISSN: 1546-1718
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] The RP14 autosomal recessive Retinitis pigmentosa (arRP) locus has been mapped to a 2cM region of chromosome 6p21.3 (refs 1–3). TULP1 (the gene encoding tubby-like protein 1) is a candidate target for the disease mutation because it maps to the RP14 minimum genetic region and because a ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/ng0298-177
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  • 10
    Electronic Resource
    Electronic Resource
    The product of hedgehog autoproteolytic cleavage active in local and long-range signalling (1995)
    [s.l.] : Nature Publishing Group
    Nature 374 (1995), S. 363-366 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] To characterize the signalling molecules produced from the uncleaved Hh precursor U, we determined the site of autoproteolysis and the structures of the cleaved products using a purified Hh protein from a bacterial source. This purified protein, His6C, contains primarily carboxy-terminal sequences ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/374363a0
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