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  • 1
    Electronic Resource
    Electronic Resource
    Pollinator foraging behavior and pollen collection on the floral morphs of tristylous Pontederia cordata L. (1987)
    Springer
    Oecologia 74 (1987), S. 347-351 
    Details
    ISSN: 1432-1939
    Keywords: Pontederia cordata ; Bombus ; Tristyly ; Pollination ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The foraging behavior of the pollinators of tristylous Pontederia cordata was studied to determine if differences in floral morphology would lead to preferential visitation of the floral morphs. Although nectar production is not different in the three floral morphs, differences in the production and size of pollen grains produced by the three anther levels results in the morphs offering variable amounts of resources to pollen-collecting insects. Bumblebees (Bombus spp.) and the solitary bee Melissodes apicata used P. cordata primarily as a nectar source and therefore did not seem to exhibit any morph preference. In contrast, honeybees visited flowers mainly for pollen and preferred to forage on long-level anthers of the short-and mid-styled morphs. An analysis of the composition of corbicular pollen loads indicated that, relative to the frequency of production in the population: 1) honeybees collected an excess of pollen from long-level anthers; 2) bumblebees collected the three types of pollen without any apparent preference; and 3) M. apicata preferentially collected pollen from the short-level anthers — presumably because their proboscides are modified by the presence of tiny hairs. The results suggest that P. cordata in Ontario is serviced by a diverse, unspecialized pollinator fauna which is not co-adapted to the tristylous floral polymorphism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378928
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  • 2
    Electronic Resource
    Electronic Resource
    Changes in the lipid composition and maximisation of the polyunsaturated fatty acid content of three microalgae grown in mass culture (1993)
    Springer
    Journal of applied phycology 5 (1993), S. 71-83 
    Details
    ISSN: 1573-5176
    Keywords: Isochrysis ; lipid ; mariculture ; mass culture ; microalgae ; Nannochloropsis ; nutrition ; Pavlova ; polyunsaturated fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three species of microalgae were grown in mass culture to investigate the influence of culture technique and growth phase on the production of 20:5(n−3) and 22:6(n−3). These polyunsaturated fatty acids (PUFA) are considered to be essential in many marine animals diets for high growth and survival rates. The species of microalgae examined wereNannochloropsis oculata, Pavlova lutheri andIsochrysis sp. (clone T.Iso). All batch cultures (logarithmic and stationary phase) and semi-continuous cultures (logarithmic phase) examined contained high levels of the long-chain (n−3) PUFA, but production could be maximised by harvesting at specific times and growth phases. Maximum cellular content (pg cell-1) of long-chain PUFA was found in logarithmic phase batch cultures ofN. oculata and in stationary phase cultures ofP. lutheri. The cellular content of PUFA in cultures ofIsochrysis sp. did not change significantly with culture technique or growth phase. Alternatively, stationary phase cultures of all three species showed increased proportions (%) and cellular contents of triacylglycerols, and saturated and monounsaturated fatty acids with correspondingly decreased proportions of polar lipids and most PUFA relative to logarithmic phase cultures. The exception was the proportion and cellular content of 22:6(n−3) inP. lutheri which increased with triacylglycerol content. The mass of long-chain (n−3) PUFA per volume of culture was significantly higher in stationary phase cultures due to the higher cell counts per volume. These findings indicate that the opportunity exists to maximise PUFA production by microalgae with the potential to improve animal growth and reduce production costs in mariculture operations and may be of use in the large scale culture and harvesting of microalgae for the biotechnology industry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02182424
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  • 3
    Electronic Resource
    Electronic Resource
    Heterostyly in the Lamiaceae: The case ofSalvia brandegeei (2000)
    Springer
    Plant systematics and evolution 223 (2000), S. 211-219 
    Details
    ISSN: 1615-6110
    Keywords: Heterostyly ; distyly ; zygomorphic flowers ; self-compatibility ; protandry ; geitonogamy ; Lamiaceae ; rare plant species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heterostyly rarely occurs in families with strongly zygomorphic flowers. For this reason Darwin (1877) doubted whether heterostyly would occur in the Lamiaceae and recent reviews have not reported the floral polymorphism in this family. Here we describe distyly in a rare species ofSalvia restricted to bluffs and seaward canyons on Santa Rosa Island (Santa Barbara Co., California) and northwestern Baja California (Mexico).Salvia brandegeei is morphologically distylous with populations composed of equal frequencies of long-and short-styled morphs differing reciprocally in stigma and anther position. Controlled hand pollinations demonstrated no significant differences in the seed set of self, intramorph or intermorph pollinations. Unlike most heterostylous species investigated,S. brandegeei does not possess diallelic incompatibility or ancillary polymorphisms of pollen and stigmas. We propose that the evolution of distyly inS. brandegeei may have been associated with an ecological shift to a new environment in which protandry failed to prevent increased levels of geitonogamy. Heterostyly was then selected because it increased the proficiency of cross-pollination. The origin of distyly in self-compatibleS. brandegeei is consistent with Lloyd and Webb's theoretical model for the evolution of distyly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985280
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  • 4
    Electronic Resource
    Electronic Resource
    Attachment of gelatin films to tissue using argon beam coagulator (1998)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 43 (1998), S. 89-98 
    Details
    ISSN: 0021-9304
    Keywords: gelatin ; films ; tissue ; bonding ; argon beam ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Cross-linked gelatin films were bonded to heart muscle and to lung pleura and parenchyma using the electrical discharge of an argon beam radiofrequency coagulator. The bonds were stable in warm saline buffer for minutes to hours. Bonding was thought to partly occur through a mechanical interlock of film and tissue elements. The interdigitation of tissue and film arose during exposure to the argon beam, which denatured protein constituents of both, and created a fluidized state that rapidly coalesced. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 43: 89-98, 1998
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
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    Choices in the climate commons (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-12-14
    Keywords: Editorials
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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