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PHYLOGENY OF THE HEXAPODA AND OVARIAN METAMERISM 总被引:3,自引:0,他引:3
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THOMAS DENK FRIÐGEIR GRÍMSSON ZLATKO KVAEK 《Botanical journal of the Linnean Society. Linnean Society of London》2005,149(4):369-417
A large number of plant macrofossils from several Middle to Upper Miocene localities from Iceland have been studied. The fossil material includes four ferns and fern allies, seven conifers, and about 40 species of flowering plants. Betula islandica and Salix gruberi are described as new species. Coniferous twigs previously ascribed to the genus Sequoia are shown to belong to Cryptomeria based on macro‐morphological and epidermal features. Fossil plants from Iceland are compared with coeval fossil taxa from Europe and North America and with living plants. The main finding is that the Miocene flora of Iceland belongs to a widespread Neogene northern hemispheric floral type including plants whose representatives are restricted to East Asia, North America and to western Eurasia at the present time. Previously inferred conspicuous similarities to North American modern equivalents appear to be misleading. The type of vegetation in four plant‐bearing sedimentary formations from the late Mid Miocene to Late Miocene, the 12 Ma Brjánslækur‐Seljá Formation, the 10 Ma Tröllatunga‐Gautshamar Formation, the 9–8 Ma Skarðsströnd‐Mókollsdalur Formation, and the 7–6 Ma Hreðavatn‐Stafholt Formation, corresponds to a humid temperate broadleaved (deciduous)–coniferous mixed forest dominated by Betulaceae, Fagaceae and Acer. Changes in species composition in the sedimentary formations reflect a shift from warm temperate (Cfa climate) to cool temperate (Cfb climate) conditions from the late Mid Miocene to the latest Miocene. This shift was connected to repeated phases of extinction and colonization. Specifically, one set of thermophilic taxa including Magnolia, Liriodendron, Sassafras and Comptonia went extinct between 12 and 10 Ma, and appears to have been replaced by another set of thermophilic taxa in the 10 Ma formation (Juglandaceae aff. Pterocarya/Cyclocarya, Rhododendron ponticum type). The 9–8 and 7–6 Ma formations are characterized by taxa that migrated to Iceland from Europe, such as Fagus gussonii, Betula cristata and Pterocarya fraxinifolia type. Although there is convincing evidence that plants colonized Iceland both from North America and Europe until 12 Ma, migration in the younger formations (9–8, 7–6 Ma) is suggested to have occurred mainly from Europe. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 149 , 369–417. 相似文献
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Proponents of controversial Complementary and Alternative Medicines, such as homeopathy, argue that these treatments can be used with great effect in addition to, and sometimes instead of, ‘conventional’ medicine. In doing so, they accept the idea that the scientific approach to the evaluation of treatment does not undermine use of and support for some of the more controversial CAM treatments. For those adhering to the scientific canon, however, such efficacy claims lack the requisite evidential basis from randomised controlled trials. It is not clear, however, whether such opposition characterises the views of the general public. In this paper we use data from the 2009 Wellcome Monitor survey to investigate public use of and beliefs about the efficacy of a prominent and controversial CAM within the United Kingdom, homeopathy. We proceed by using Latent Class Analysis to assess whether it is possible to identify a sub-group of the population who are at ease in combining support for science and conventional medicine with use of CAM treatments, and belief in the efficacy of homeopathy. Our results suggest that over 40% of the British public maintain positive evaluations of both homeopathy and conventional medicine simultaneously. Explanatory analyses reveal that simultaneous support for a controversial CAM treatment and conventional medicine is, in part, explained by a lack of scientific knowledge as well as concerns about the regulation of medical research. 相似文献
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Abstract The species of Dirhinini from the Indian Subcontinent are revised and a key given to the ten recognized species. These are classified in one genus, Dirhinus Dalman, with two subgenera. Four new species, claviger, deplanatus, pilifer and altispina , are described and seventeen new synonyms (sixteen specific, one generic) proposed. All pertinent biological data are critically reviewed, all host records being from Diptera, especially synanthropic muscoid flies, noxious fruitflies and tachinids. Observations are made on geographic distributions, two species being found to extend from Africa to the Hawaiian Islands. 相似文献
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