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  • 1
    Electronic Resource
    Electronic Resource
    Patterns of fusimotor innervation by γ-efferents in cat peroneus tertius (1983)
    Springer
    Experimental brain research 51 (1983), S. 146-152 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindles ; γ-Efferents ; Fusmotor innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pattern of γ-efferent innervation of the muscle spindle was investigated in the peroneus tertius muscle of the cat. A number of spindle group Ia afferents were isolated and monitored during tetanic stimulation of isolated γ-axons. The sample was dominated by efferents producing a static fusimotor effect on the afferent. An individual static axon normally projected to less than five but at times as many as seven muscle spindles. Each spindle normally received innervation from three to five static γ-efferents but occasionally up to eight. The number of spindles innervated by a static γ-axon was directly related to the efferent axonal conduction velocity. For each experiment, a probability distribution of the number of fusimotor effects was constructed from all available connections between the muscle spindles and static γ-efferents considered in matrices of four afferents and four efferents. This distribution was then compared to a random binomial distribution. In each of the ten experiments, statistically significant differences (p〈0.01) were noted between the experimental and random distributions. In order to interpret such deviations from the random distributions, similar analyses were performed on various combinations of afferents and efferents in simulated sets displaying grouping of effects. It was concluded that the observed differences between experimental and random distributions may be produced by a grouping of fusimotor innervation limited to a small set of spindles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236812
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  • 2
    Electronic Resource
    Electronic Resource
    Histochemical evidence for the existence of skeletofusimotor (β) innervation in the primate (1982)
    Springer
    Experimental brain research 46 (1982), S. 186-190 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindles ; Skeletofusimotor efferents ; \ Innervation ; Glycogen depletion ; Primate motor control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A total of ten a motor axons which innervated the peroneus brevis muscle were isolated in two cynomolgus monkeys. In each experiment, the isolated α axons were stimulated collectively to deplete glycogen from their muscle units. The muscle was then frozen quickly, cut serially, and stained for glycogen. Of the 52 muscle spindles that were examined, zones of glycogen depletion were found in the intrafusal fibres of 32 spindles. The glycogen-depleted motor units included both fast-twitch and slow-twitch types. Depleted zones were observed in all three types of intrafusal muscle fibres. It was concluded that skeletofusimotor (β) efferents were among the stimulated motor axons. This finding constitutes the first anatomical evidence for the existence of β innervation in the primate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237175
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  • 3
    Electronic Resource
    Electronic Resource
    Exsolution in ‘stoichiometric’ mullite (1976)
    [s.l.] : Nature Publishing Group
    Nature 264 (1976), S. 736-738 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] In the course of a study of solid solution in mullite a number of occurrences of rocks with coexisting sillimanite and mullite were found5. The most obvious way that this could come about would be if reactions (1) or (2) had not gone to completion: 3Al2SiO5-〉3Al2O3. 2SiO2+SiO2 2Al2SiO5+Al203 ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/264736a0
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  • 4
    Electronic Resource
    Electronic Resource
    Petrology and geochemistry of Cambrian boninites and low-Ti andesites from Heathcote, Victoria (1985)
    Springer
    Contributions to mineralogy and petrology 91 (1985), S. 93-104 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract In the Heathcote Greenstone Belt of central Victoria, a sequence of boninites and low-Ti andesites is overlain and intruded by tholeiitic basalts with affinities to backarc basin basalts. Two suites of boninites have been identified: one (Type A) with Ti/Zr ratios of 63±4, (La/Yb)N of 2–3 and HREE 5 times chondritic levels. The other suite (Type B) overlies Type A boninites and has Ti/Zr ratios of 23±3 and lower TiO2 and HREE contents (2–3 × chondrite), but shows significantly greater LREE enrichment, with (La/Yb)N greater than 5. Fractionation within both suites was largely controlled by the low-Ca pyroxenes protoenstatite and enstatite. Plagioclase-phyric low-Ti, high-Mg andesites occur in fault contact with the boninites, and have Ti/Zr and (La/Yb)N ratios very close to those of Type B boninites, but at higher absolute abundances of TiO2 and HREE. They are not related to either boninite suite by any realistic fractionation scheme, but originated from the same source as Type B boninites by approximately half the degree of partial melting that generated the boninites. Type A boninites could have been generated when LILE-enriched hydrous fluids derived from a subducted slab invaded depleted, clinopyroxene-poor lherzolite at depths less than 30 km, and initiated H2O-undersaturated partial melting. In a later partial melting event at similar depths, continued influx of metasomatic fluids into by now highly-depleted peridotite could have generated Type B boninites and low-Ti andesites. The presence of boninites and low-Ti andesites in the Cambrian Heathcote and Mount Wellington Greenstone Belts in southeastern Australia suggests that the early history of the Lachlan Foldbelt took place in a subduction-related, intraoceanic setting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429431
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  • 5
    Electronic Resource
    Electronic Resource
    Boninites, komatiites and ophiolitic basalts (1979)
    [s.l.] : Nature Publishing Group
    Nature 280 (1979), S. 550-553 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The rare Phanerozoic rock type boninite petrographically resembles Archaean basaltic komatiites and the range of boninite compositions overlaps that of basaltic komatiites. Quench amphibole and hydrous glass in the groundmass of boninites confirm earlier ideas that they may be the products of ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/280550a0
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  • 6
    Electronic Resource
    Electronic Resource
    Permo–Triassic and Jurassic 40 Ar– 39 Ar ages from Greek ophiolites and associated rocks (1979)
    [s.l.] : Nature Publishing Group
    Nature 279 (1979), S. 788-790 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The breakup of a continental area in what is now the Othris region began in early Mesozoic time1. It is believed to be contemporaneous with the formation of picrites, wehrlites, dolerites, pillow lavas, tuffs and the deposition of associated cherts and dolomites assigned to the Agrilia Formation2. ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/279788a0
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  • 7
    Electronic Resource
    Electronic Resource
    Palaeogene komatiites from Gorgona Island (1979)
    [s.l.] : Nature Publishing Group
    Nature 278 (1979), S. 545-546 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Mineral composition: quenched coarse olivine blades up to 5 cm long and 1 mm thick dominate the spinifex texture. The blades are Fo90-9i with narrow edges of Fo85_86. Clinopyroxenes and plagioclases are restricted to the interstitial groundmass (Fig. 1). High-aluminium calcic pyroxenes exhibit ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/278545a0
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  • 8
    Electronic Resource
    Electronic Resource
    Blaubleibender covellite and its relationship to normal covellite (1977)
    Springer
    Contributions to mineralogy and petrology 60 (1977), S. 209-217 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Both natural and synthetic samples of blaubleibender (blue-remaining) covellite have been studied by reflected light microscopy, electron probe microanalysis and electron microscopy and diffraction. The natural sample of composition Cu1.20S has a √19a × √19a superstructure based on the hexagonal coveilite subcell (side a). The synthetic sample of composition Cu1.10S has a 2√7 a × 2 √7a superstructure. In both cases the phases are homogeneous. The evidence suggests that the recognition of two distinct types of blaubleibender covellite may be an oversimplification, and that a series of metastable superstructures based on the covellite structure may exist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00372282
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  • 9
    Electronic Resource
    Electronic Resource
    Boninite petrogenesis and alteration history: constraints from stable isotope compositions of boninites from Cape Vogel, New Caledonia and Cyprus (1986)
    Springer
    Contributions to mineralogy and petrology 93 (1986), S. 222-226 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract δ 18O values of unaltered olivine and pyroxene phenocrysts in boninites from several areas range from 5.8 to 7.4 and indicate that the source for most boninites is more 18O-rich than MORBs and other oceanic basalts. The source for oxygen and other major elements is most likely a refractory portion of the mantle having a δ 18O value of up to 7.0 to which must be added a small amount of H2O-rich fluid to induce partial melting. This fluid, which is derived from subducted crust, is the vehicle for LREEs including Nd. The variable, normally low ɛ Nd values typical of boninites do not correlate with the δ 18O values. Post eruptive exchange of oxygen in the glass of boninites with that of sea water at low temperatures (〈150° C) produces δ 18O values of 〉10 in optically fresh glass. Hydration of the glass has increased the water contents of most boninites from estimated magmatic values of 1–2 wt% to 2–4 wt% and produced δD values of 〈 −80, which may be lower than the original magmatic δD values. In contrast to most submarine pillow basalts, the magmatic volatile composition of boninite lavas has been extensively modified as a result of post eruptive interaction with seawater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00371324
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  • 10
    Electronic Resource
    Electronic Resource
    Petrology and origin of primitive lavas from the Troodos ophiolite, Cyprus (1985)
    Springer
    Contributions to mineralogy and petrology 89 (1985), S. 239-255 
    Details
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Parental magmas to the Troodos ophiolite are characterised by low TiO2 and Al2O3 and high SiO2. Extremely fresh and chemically primitive (high MgO) rocks are found within the Upper Pillow Lavas and along the Arakapas Fault Belt of Cyprus and contain forsteritic olivine±enstatite and groundmass clinopyroxene set in glass or plagioclase, with accessory magnesiochromite and sometimes hornblende. They are quartz-normative and may have originally contained up to 3 wt% H2O. Geochemically, there are three distinct groups of primitive lavas, based on TiO2 and Zr contents but also reflected by CaO, Na2O and REE abundances. These groups cannot be related by crystal fractionation and are considered to have been generated by incremental melting of a variably depleted source region. The parental magma to the least depleted group (Group I) was that of the major portion of the Troodos plutonic complex and is similar to those postulated for other “low-Ti” ophiolites. Chemically it has close affinities with komatiitic basalts. The most depleted lavas (Group III) all have U-shaped REE profiles and variable 143Nd/ 144Nd ratios, interpreted in terms of metasomatism of the source region by an incompatible element-enriched component which was probably derived from a subducted slab. These lavas represent an intermediate step in the development of boninite series rocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00379457
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