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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 102 (1989), S. 161-165 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Porichthys notatus is a common benthic fish found along the Pacific coast of North America. It possesses more than 700 small dermal photophores on its head and trunk. When P. notatus collected in Monterey Bay, California, is injected subcutaneously with norepinephrine, the photophores emit a long-lasting luminescence that is readily visible to the dark-adapted eye. The light emission is due to the oxidation of luciferin (substrate) by molecular oxygen, catalyzed by luciferase. In contrast, P. notatus collected in Puget Sound, Washington, is nonluminous, even though the photophores do not differ ultrastructurally from those of the California fish. The inability of the Puget Sound fish to luminesce is due to lack of luciferin in its photophores. Luminescence capability, however, may be induced in the Puget Sound fish by the oral or intraperitoneal administration of a small amount of luciferin from the tiny luminescent marine ostracod crustacean, Vargula hilgendorfii, suggesting that the origin of luciferin in P. notatus may be from the diet. In this study, specimens of P. notatus were collected over the entire known range of the species, between November 1981 and September 1987, and the presence of luciferin in the photophores determined. The results indicate that there are two populations of P. notatus: a luciferin-deficient, nonluminescent population located north of northern California and a luciferin-containing, luminescent population extending south of Cape Mendocino, California, to Baja California, Mexico. At the northern end of the southern population, a mixture of luminescent and nonluminescent P. notatus was found.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 185 (1960), S. 535-536 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Following oral administration of chloramphenicol palmitate, the urine of adult cats and newborn infants was examined by paper chromatography. The solvent system was water-saturated butanol containing 2-5 per cent phenol and 2 per cent pyri-dine1. Strips of Whatman No. 1 paper were used in the ...
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  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] THE article on “War, Science and Citizenship” in NATURE of May 9, and the letter on “Scientific Workers and War” published in the following week have expressed views no doubt widely held among readers of NATURE. Neither, however, gives any adequate suggestion as to how those scientific workers ...
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 543 (1988), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bioluminescent fish Porichthys notatus (plainfin midshipman), has a discontinuous distribution along the Pacific coast of North America. The fish is present from Cape Mendocino southward to Baja California, Mexico, absent off the coast of Oregon, USA, and abundant, northward, in Puget Sound, Washington. Interestingly, the population in Puget Sound lacks the substrate (luciferin) necessary for the luminescence reaction and, despite possessing an otherwise fully functional photophore system, is nonluminescent. The California population of P. notatus is uniformly luminescent south of Monterey Bay, but 15% of the speciments tested from San Francisco Bay and the Gulf of the Farallons have been reported to be nonluminescent. Explanations for nonluminescent midshipman in both Puget Sound and the San Francisco Bay area have focussed on a dietary requirement for luciferin. To gain further insight into reasons for nonluminescence in the San Francisco Bay region, the distribution of bioluminescence in P. notatus was studied from Monterey Bay to Cape Mendocino during 1985. A complex pattern of bioluminescence was found, in which nonluminescent individuals reflected neither a local anomaly in the San Francisco Bay region nor a simple gradient of decreasing luminescence towards the northern end of the range of the California population. Instead, a distinct size-dependent component in luminescence capability of the fish was observed. Aspects of the life history of P. notatus and related factors which might influence the bioluminescence characteristics of this population are discussed.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Human genetics 〈Berlin〉 61 (1982), S. 269-272 
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A stillborn short-limbed platyspondylic dwarf is described. Detailed analysis of the X-ray and histological characteristics of bone and cartilage suggest that this infant represents a previously unreported variant of short-limbed platyspondylic dwarfism. The designation “Luton variant” is suggested.
    Type of Medium: Electronic Resource
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  • 7
    Publication Date: 1995-02-28
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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  • 8
    Publication Date: 1989-09-01
    Description: The marine ostracod Vargula hilgendorfii ejects luciferin and luciferase into seawater to produce a bright luminous cloud. The light is due to the oxidation of luciferin, an imidazopyrazine compound, by molecular oxygen, catalyzed by luciferase. The mechanism of the reaction has been studied extensively and the 60 kcal/mol required for the blue emission have been shown to be derived from the oxidation of luciferin via a dioxetanone intermediate, in which the excited state oxyluciferin bound to luciferase is the emitter. However, only limited information is available regarding the properties of the enzyme. This paper reports the cloning and sequence analysis of the cDNA for Vargula luciferase and the expression of the cDNA in a mammalian cell system. The primary structure, deduced from the nucleotide sequence, consists of 555 amino acid residues in a single polypeptide chain with a molecular weight of 62,171. Two regions of the enzyme show significant amino acid sequence homology with an N-terminal segment of the photoprotein aequorin. The Vargula luciferase gene, which contains a signal sequence for secretion, should be well suited as a reporter in studies of gene expression.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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  • 9
    Publication Date: 2013-06-08
    Description: Because of the limited number of strong-motion records that have measured ground response at large strains, any statistical analyses of seismic site-response models subject to strong ground motions are severely limited by a small number of observations. Recent earthquakes in Japan, including the M w  9.0 Tohoku earthquake of March 2011, have substantially increased the observations of strong-motion records that can be used to compare alternative site-response models at large strains and can subsequently provide insight into the accuracy and precision of site-response models. Using the Kiban-Kyoshin network (KiK-net) downhole array data in Japan, we analyze the accuracy (bias) and variability (precision) resulting from common site-response modeling assumptions, and we identify critical parameters that significantly contribute to the uncertainty in site-response analyses. We perform linear and equivalent-linear site-response analyses at 100 KiK-net sites using 3720 ground motions ranging in amplitude from weak to strong; 204 of these records have peak ground accelerations greater than at the ground surface. We find that the maximum shear strain in the soil profile, the observed peak ground acceleration at the ground surface, and the predominant spectral period of the surface ground motion are the best predictors of where the evaluated models become inaccurate and/or imprecise. The peak shear strains beyond which linear analyses become inaccurate in predicting surface pseudospectral accelerations (PSA; presumably as a result of nonlinear soil behavior) are a function of vibration period and are between 0.01% and 0.1% for periods 〈0.5 s. Equivalent-linear analyses become inaccurate at peak strains of ~0.4% over this range of periods. We find that, for the sites and ground motions considered, site-response residuals at spectral periods 〉0.5 s do not display noticeable effects of nonlinear soil behavior. Online Material: Site-specific information and model residuals at 100 KiK-net stations.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
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  • 10
    Publication Date: 2016-04-07
    Description: Methods that account for site response range in complexity from simple linear categorical adjustment factors to sophisticated nonlinear constitutive models. Seismic-hazard analysis usually relies on ground-motion prediction equations (GMPEs); within this framework site response is modeled statistically with simplified site parameters that include the time-averaged shear-wave velocity to 30 m ( V S 30 ) and basin depth parameters. Because V S 30 is not known in most locations, it must be interpolated or inferred through secondary information such as geology or topography. In this article, we analyze a subset of stations for which V S 30 has been measured to address effects of V S 30 proxies on the uncertainty in the ground motions as modeled by GMPEs. The stations we analyze also include multiple recordings, which allow us to compute the repeatable site effects (or empirical amplification factors [EAFs]) from the ground motions. Although all methods exhibit similar bias, the proxy methods only reduce the ground-motion standard deviations at long periods when compared to GMPEs without a site term, whereas measured V S 30 values reduce the standard deviations at all periods. The standard deviation of the ground motions are much lower when the EAFs are used, indicating that future refinements of the site term in GMPEs have the potential to substantially reduce the overall uncertainty in the prediction of ground motions by GMPEs.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
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