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  • 1
    Electronic Resource
    Electronic Resource
    Torsional oscillation patterns in photospheric magnetic features (1993)
    Springer
    Solar physics 143 (1993), S. 19-39 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We analyzed 689 high-resolution magnetograms taken daily with the NSO Vacuum Telescope on Kitt Peak from 1975 to 1991. Motions in longitude on the solar surface are determined by a one-dimensional crosscorrelation analysis of consecutive day pairs. The main sidereal rotation rate of small magnetic features is best fit byω = 2.913(±0.004) − 0.405(±0.027) sin2 φ − 0.422(±0.030) sin4 φ, in µrad s−1, whereφ is the latitude. Small features and the large-scale field pattern show the same general cycle dependence; both show a torsional oscillation pattern. Alternating bands of faster and slower rotation travel from higher latitudes toward the equator during the solar cycle in such a way that the faster bands reach the equator at cycle minimum. For the magnetic field pattern, the slower bands coincide with larger widths of the crosscorrelations (corresponding to larger features) and also with zones of enhanced magnetic flux. Active regions thus rotate slower than small magnetic features. This magnetic torsional oscillation resembles the pattern derived from Doppler measurements, but its velocities are larger by a factor of more than 1.5, it lies closer to the equator, and it leads the Doppler pattern by about two years. These differences could be due to different depths at which the different torsional oscillation indicators are rooted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619094
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  • 2
    Electronic Resource
    Electronic Resource
    Reproductive success in the Caribbean octocoral Briareum asbestinum (1992)
    Springer
    Marine biology 114 (1992), S. 157-163 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract For most sessile marine invertebrates the number of offspring produced by an individual is often determined indirectly from counts of eggs present, with the assumption that all or most become viable offspring. Few field data on the actual number of offspring produced per individual (reproductive success) have been reported. We examined reproductive success in the octocoral, Briareum asbestinum (Pallas), by measuring embryo densities on 40 female colonies on two reefs (Pinnacles and House reefs) in the San Blas Islands, Panama from 1986 to 1988. The percentage of female colonies with mature eggs which subsequently released embryos was low, ranging from 46.6% in 1986 to 5.0% in 1988. Reproductive success was significantly different between reefs. Pinnacles reef had significantly more successful colonies (those releasing embryos) than House reef in all three years and significantly higher embryo densities in 1986 and 1987. There was a significant positive correlation between female reproductive success and the density and proximity of nearby males in both 1986 and 1987. In addition, fertile female branches placed 25 cm away from male branches produced significantly more embryos than female branches placed 50 cm away. In 1988 two groups of female branches were placed at distances of 〈50 cm and 5 m from four large male colonies at Pinnacles reef. Of the 20 female branches placed 5 m from the males none released embryos while 35% (7 of 20 branches) of the branches 〈50cm from males released embryos. These data indicate that simple counts of mature eggs present within female colonics prior to the reproductive season provide a poor estimate of reproductive success in B. ashestinum and that female reproductive success is positively influenced by the close proximity of males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00350865
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  • 3
    Electronic Resource
    Electronic Resource
    DNA fingerprints of a gorgonian coral: a method for detecting clonal structure in a vegetative species (1992)
    Springer
    Marine biology 114 (1992), S. 317-325 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal reproduction, a common life history strategy among sessile marine invertebrates, can lead to high local abundances of one to a few genotypes in a population. Analysis of the clonal structure of such populations can provide insight into the ecological and evolutionary history of the population, but requires markers that can identify individual genets. Forensic and demographic studies have demonstrated that DNA fingerprinting can provide markers that are unique for an individual genotype. We have generated DNA fingerprints for over 70 colonies of the clonal gorgonian, Plexaura A (Plexaura sp. A) collected from June 1990 through July 1991 in the San Blas Islands, Panama. DNA fingerprints within a singic individual were identical and fingerprinting resolved multiple genotypes within and among reefs. On one reef in the San Blas Islands, Panama, 59% of the colonies sampled were of one genotype and this genotype was not found on any other sampled reefs. A previous study using tissue grafts identified 13 putative clones on these reefs, while DNA fingerprints of the same colonies differentiated 17 genotypes. The present study demonstrates the utility of DNA fingerprinting for distinguishing clones and for identifying clonal structure of marine invertebrate populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349534
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  • 4
    Electronic Resource
    Electronic Resource
    Meridional flow of small photospheric magnetic features (1993)
    Springer
    Solar physics 147 (1993), S. 207-223 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We study the meridional flow of small magnetic features, using high-resolution magnetograms taken from 1978 to 1990 with the NSO Vacuum Telescope on Kitt Peak. Latitudinal motions are determined by a two-dimensional crosscorrelation analysis of 514 pairs of consecutive daily observations from which active regions are excluded. We find a meridional flow of the order of 10 m s−1, which is poleward in each hemisphere, increases in amplitude from 0 at the equator, reaches a maximum at mid-latitude, and slowly decreases poleward. The average observed meridional flow is fit adequately by an expansion of the formM (θ) = 12.9(±0.6) sin(2θ) + 1.4(±0.6) sin(4θ), in m s−1 whereθ is the latitude and which reaches a maximum of 13.2 m s−1 at 39°. We also find a solar-cycle dependence of the meridional flow. The flow remains poleward during the cycle, but the amplitude changes from smaller-than-average during cycle maximum to larger-than-average during cycle minimum for latitudes between about 15° and 45°. The difference in amplitude between the flows at cycle minimum and maximum depends on latitude and is about 25% of the grand average value. The change of the flow amplitude from cycle maximum to minimum occurs rapidly, in about one year, for the 15–45° latitude range. At the highest latitude range analyzed, centered at 52.5°, the flow is more poleward-than-average during minimumand maximum, and less at other times. These data show no equatorward migration of the meridional flow pattern during the solar cycle and no significant hemispheric asymmetry. Our results agree with the meridional flow and its temporal variation derived from Doppler data. They also agree on average with the meridional flow derived from the poleward migration of the weak large-scale magnetic field patterns but differ in the solar-cycle dependence. Our results, however, disagree with the meridional flow derived from sunspots or plages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690713
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  • 5
    Electronic Resource
    Electronic Resource
    Mandibular gland secretions of the male beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher (Hymenoptera: Sphecidae) (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 27-37 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus crabroniformis ; Philanthus barbatus ; Philanthus pulcher ; Hymenoptera ; Sphecidae ; beewolf ; mandibular glands ; pheromones ; semiochemicals ; mass spectrometry ; infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The composition of the territorial marking pheromones from mandibular glands of males of the beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher have been determined. The structures of the components were elucidated by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major compound ofP. crabroniformis is isopropyl tetradecanoate, with somewhat lesser amounts of 2-tridecanone, 3-methyl-3-butenyl tetradecanoate, and 92∶8 (Z)∶(E)-11-eicosen-1-ol. The major compounds ofP. barbatus are ethyl tetradecanoate and hexadecanal, which are present in approximately a 60∶40 ratio. These two compounds comprise over 95% of the neutral lipids. Also present in lesser amounts are ethyl dodecanoate, tetradecanal, hexadecan-1-ol, a Δ x -octadecen-1-ol, and octadecan-1-ol. The major compounds ofP. pulcher are ethyl (Z)-7-hexadecenoate and geranylgeraniol acetate, which comprise nearly 90% of the neutral lipid fraction, with smaller amounts of tetradecanal, pentadecanal, and ethyl hexadecanoate; trace amounts of Δ x hexadecenal, hexadecanal, and octadecanal are also present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00997162
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  • 6
    Electronic Resource
    Electronic Resource
    Actin in penetration pegs of the fungal rice blast pathogen,Magnaporthe grisea (1992)
    Springer
    Protoplasma 168 (1992), S. 20-26 
    Details
    ISSN: 1615-6102
    Keywords: Appressoria ; Freeze substitution ; Immunofluorescence ; Plant disease ; Phalloidin ; Pyricularia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The penetration peg is the structure used byMagnaporthe grisea to pierce the surface of rice leaves or very hard nonbiodegradable substrates. Penetration pegs produced by appressoria in vitro were examined by electron microscopy and immunofluorescence microscopy using various fluorophore labeled anti-actins. Freeze-substitution preparation of appressoria at early stages of substrate penetration showed that peg cytoplasm consisted primarily of a zone of exclusion, excluding even ribosomes, and was continuous with a similar region in the appressorium. Apical vesicles were, however, observed in short, presumably elongating pegs. Immunofluorescence microscopy was used to demonstrate binding of a monoclonal anti-actin to penetration peg cytoplasm, following “permeabilization” of appressoria by means of a brief sonication. Occasional filaments and ca. 300 nm diameter plaques were labeled in appressorial cytoplasm. Western blot analysis of germ tube extracts showed that the monoclonal probe bound predominantly to a single band with a molecular weight similar to that of rabbit muscle actin. Preincubation of the antibody with actin virtually eliminated peg labeling. We conclude that the penetration peg contains actin which may play a role in the formation of the zone of exclusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01332647
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  • 7
    Electronic Resource
    Electronic Resource
    Rotation rates of small magnetic features from two- and one-dimensional cross-correlation analyses (1993)
    Springer
    Solar physics 145 (1993), S. 1-10 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present results of an analysis of 628 high-resolution magnetograms taken daily with the NSO Vacuum Telescope on Kitt Peak from 1975 to 1991. Motions in longitude on the solar surface are determined by a two-dimensional cross-correlation analysis of consecutive day pairs. We find that the measured rotation rate of small magnetic features, i.e., excluding active regions, is in excellent agreement with the results of the previous one-dimensional analysis of the same data (Komm, Howard, and Harvey, 1993). The polynomial fits show magnetic torsional oscillations, i.e., a more rigid rotation during cycle maximum and a more differential rotation during cycle minimum, but with smaller amplitudes than the one-dimensional analysis. The full width at half maximum of the cross-correlations is almost constant over latitude which shows that the active regions are effectively excluded. The agreement between the one- and two-dimensional cross-correlation analyses shows that the two different techniques are consistent and that the large-scale motions can be divided into rotational and meridional components that are not affected by each other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00627979
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  • 8
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    Torsional oscillation patterns in photospheric magnetic features (1993)
    Springer
    Details
    Publication Date: 1993-01-01
    Print ISSN: 0038-0938
    Electronic ISSN: 1573-093X
    Topics: Physics
    Published by Springer
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  • 9
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    Meridional flow of small photospheric magnetic features (1993)
    Springer
    Details
    Publication Date: 1993-10-01
    Print ISSN: 0038-0938
    Electronic ISSN: 1573-093X
    Topics: Physics
    Published by Springer
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  • 10
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    Tracking of Coronal White-Light Events by Texture (2010)
    Springer
    Details
    Publication Date: 2010-01-20
    Print ISSN: 0038-0938
    Electronic ISSN: 1573-093X
    Topics: Physics
    Published by Springer
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