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  • 1
    Electronic Resource
    Electronic Resource
    INTERREGIONAL ECONOMIC MIGRATION: SOME THEORETICAL CONSIDERATIONS (Part I) (1975)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of regional science 15 (1975), S. 0 
    Details
    ISSN: 1467-9787
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geography , Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1467-9787.1975.tb00915.x
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  • 2
    Electronic Resource
    Electronic Resource
    Feeding rhythmicity in a migratory copepod (Pseudodiaptomus hessei (Mrázek)) (1977)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 7 (1977), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. This paper describes a day/night feeding rhythm in the copepod Pseudodiaptomus hessei in subtropical Lake Sibaya (27°20′ S, 32°40′ E) and examines the origin of this rhythmicity on the basis of field and laboratory observations.Under natural conditions, adult and late copepodite stages (CIV-CV) of this copepod were predominantly benthic during daylight and migrated at dusk into pelagic waters in which they remained until dawn. Pronounced changes in feeding activity (based on the proportion of animals which contained food in the gut) were associated with this transition from a benthic to pelagic distribution; feeding activity was low by day and high at night. The younger copepodite stages (CI-CIII) were less strongly benthic during daylight and showed correspondingly less pronounced diel changes in feeding activity.Laboratory experiments involving concurrent light/dark and continuous dark regimes showed that batches of adult and CIV—CV stages fed throughout 24 h, although faecal pellet production increased with time under both light regimes. The laboratory observations are interpreted as negating the possibility that diel differences observed in the field arose through an endogenous feeding rhythm. The possibility that food resources in near-bottom waters was inadequate to support reasonable feeding activity is rejected on several counts. It is concluded that the feeding rhythm in P. hessei arises from an inferred infaunal distribution during daylight which would preclude filter-feeding activity. The circumstantial evidence supporting this suggestion is given and the suggestion is evaluated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1977.tb01651.x
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  • 3
    Electronic Resource
    Electronic Resource
    Horizontal distribution of the copepod Pseudodiaptomus hessei in subtropical Lake Sibaya (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 8 (1978), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. The horizontal distribution of nauplii, CI-CIII, CIV-Cv and adult stages of the copepod Pseudodiaptomus hessei within the main basin of Lake Sibaya (27° 20′ S, 32° 37′ E) is described on the basis of semi-synoptic cruises on 6 August 1971, 28 January 1972 and 11 February 1972. The distribution observed is considered in relation to variations in food availability and water temperature over this homothermal lake. It is concluded that these factors are not primarily responsible for observed patterns of distribution. Rather, wind-induced currents appear to be of major significance in determining horizontal distribution. Stage-related differences in the nature and extent of horizontal redistribution following severe wind are described. A consideration of the vertical distribution of groups of life-history stages over a diel cycle in relation to the direction and relative strength of currents encountered by the copepods within their respective depth ranges provides an explanation for the differences in horizontal redistribution observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1978.tb01464.x
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  • 4
    Electronic Resource
    Electronic Resource
    The substrate bin—a new sampling device for studying diel vertical migratory movements on to and off lake sediments (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 6 (1976), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The substrate bin, used to study diel migratory movements of the copepod Pseudodiaptomus hessei on to and off bottom interfacial areas is described. It consists essentially of a transparent Perspex box open at its upper end and supported upright within a metal framework. A lid, hinged along one face of the open end of the bin, opens and closes automatically through a simple system of levers as the apparatus is lowered on to or raised off a solid substrate.The apparatus is lowered on to the lake bed where it opens. Diel movements on to or off the shallow layer of bottom substrate enclosed within the bin can be examined by retrieving bins serially at different times.Using this apparatus in conjunction with standard net sampling techniques, clear evidence for an alternation of benthic and pelagic phases during diel cycles was obtained. Notwithstanding an apparent oversampling of the benthic component, the magnitude of which cannot be defined precisely, it is concluded that the apparatus provides a simple and reliable method of sampling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1976.tb01599.x
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  • 5
    Electronic Resource
    Electronic Resource
    The distribution and diel vertical migration of Pseudodiaptomus hessei (Mrázek) (Calanoida: Copepoda) in a subtropical lake in southern Africa (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 6 (1976), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The vertical distribution and diel migratory behaviour of Pseudodiaptomus hessei in a freshwater lake is described. All stages showed a pronounced diel migration.During daylight naupliar and copepodite instars were almost exclusively benthic in shallow areas (〈10m). Copepodite V and adult stages were predominantly benthic even at 40 m. The diurnal vertical distribution pattern implies age-related differences in photosensitivity and a possible depth-regulatory mechanism, based on the existence of differential photosensitivity, is offered to account for day-depth control.Nocturnal vertical distribution, studied approximately fortnightly during 1970–71, showed no clear seasonal variation. Variations in pattern, most obvious in adult instars, correlated with prevalent lunar conditions. Nocturnal or midnight sinking was evident, particularly in post-naupliar stages.Dusk rise and dawn descent were performed at very low light intensities and paralleled changes in light penetration. Dawn descent was less rapid than the dusk rise. An ephemeral dawn rise was sometimes observed but was not a consistent feature of all stages. An endogenous rhythm of locomotor activity was recorded under laboratory conditions. Activity was low during daylight, increased sharply at dusk and then decreased through the night to reach daytime levels at dawn. The stimulus provided by changes in light intensity and/or endogenous activity changes can account for the dusk and dawn movements of P. hessei but a definitive identification of the direct migratory stimulus is not possible. Attention is called to a closer examination of the role of endogenous activity rhythms in vertical migratory behaviour.The possible adaptive value of vertical migration to P. hessei is examined briefly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1976.tb01603.x
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  • 6
    Electronic Resource
    Electronic Resource
    Binding of Aluminum and Aluminum Alizarin to Alginate (1976)
    s.l. : American Chemical Society
    Macromolecules 9 (1976), S. 483-489 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma60051a019
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  • 7
    Electronic Resource
    Electronic Resource
    INTERREGIONAL ECONOMIC MIGRATION: SOME THEORETICAL CONSIDERATIONS (PART II) (1975)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of regional science 15 (1975), S. 0 
    Details
    ISSN: 1467-9787
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geography , Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1467-9787.1975.tb00932.x
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    Paper (German National Licenses)
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  • 8
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    Unknown
    The Obverse Side of Aristophanes (1897)
    London : Periodicals Archive Online (PAO)
    The Contemporary Review. 71 (1897:Jan./June) 662 
    Details
    ISSN: 0010-7565
    Topics: General, Interdisciplinary
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:0274-1897-071-00-000053
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  • 9
    Electronic Resource
    Electronic Resource
    IN VITRO ASSESSMENT AND MECHANISM OF ACTION OF ENVIRONMENTAL POLLUTANTS (1977)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 298 (1977), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1977.tb19260.x
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  • 10
    Electronic Resource
    Electronic Resource
    Stimulation induced depletion of the synaptic vesicles in excitatory motor nerve terminals of the locust,Locusta migratoria L (1978)
    Springer
    Cellular and molecular life sciences 34 (1978), S. 207-208 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural stimulation at high frequency induced gross changes in the ultrastructural properties and depleted the synaptic vesicles in fast axon terminals of locust extensor tibiae muscles. After a 1-h-rest the synaptic vesicle populations recovered and the ultrastructural properties of these recovering neuromuscular junctions closely resembled those of the controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01944680
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