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1.
Sydney Parkinson, aged 18, was Sir Joseph Banks' private assistant and artist on Captain Cook's first voyage around the world. Parkinson died on the voyage. Among his effects delivered to his brother Stanfield were drawings and notes which the latter published as a journal. Included in it is a chapter on the economic plants of Tahiti, and most of them are given scientific names, some of which were new. In 1941 Fosberg adopted two of them to form names which were new combinations under Artocarpus , and Inocarpus . The writer now indicates that Parkinson's names of 1773 were mononomials, hence invalid, but that in the German edition of 1774, edited by Herr "Z", the names are valid binomials. For the two plants mentioned, the authorship of the combinations is revised.  相似文献   
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Abstract The aims of this work were to discover the distribution within the C4 grass Spartina anglica of a PEP carboxylase which is very unstable during and after extraction, and to determine whether this unstable form occurs in other members of the genus. In S. anglica, only the leaf contains an unstable PEP carboxylase. Within the leaf only the major one of two isoenzymes is unstable, and this is located in the mesophyll cells. The unstable isoenzyme is inactivated during extraction and storage unless protected by bovine serum albumin or Triton X-100, and is inactivated in assay mixtures at optimum pH in the absence of PEP. Evidence is presented that inactivation is not due to degradation or inhibition during extraction and storage. The enzyme from leaves of Spartina species taxonomically closely related to S. anglica is also very unstable during and after extraction, but that from less closely related species is much more stable.  相似文献   
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Employing genetic theory as an analog, the paper argues that when the concept of culture is separated from the concept of society, anthropology can be shown to have depended for culture-change theory on a genetic model, which predicts pre-Columbian contact between the Old and New World, a prediction which is supported by a growing list of cultural parallels . [prehistoric transpacific contact, culture, society, culture change, scientific explanation]  相似文献   
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Analysis of 1,063 stomach contents from 39 species of sea snakesindicates that about one-third of the shallow, warm, marine,Indo-Australian fish families are preyed upon by sea snakes.Families of eels and gobies are taken by the greatest numbersof snake species. Most species of sea snakes feed on fish familieswhose members are relatively sedentary, dwelling along the bottom,within burrows or reef crevices. With one exception, a fishegg-eating specialization found uniquely in the Aipysurus-Emydocephaluslineage, the dietary habits of sea snakes cannot be categorizedaccording to the snakes' three phylogenetic lineages. Eels,mullet-like, rabbitfish-like and goby-like fish forms are takenby all three lineages. Two or three snake species are generalists,and numerous ones specialize on eels, goby-like fish or catfish.There are differences among sea snake species in the relationshipbetween snake neck girth and the maximum diameter of the prey;in the relationships of both snake gape measurements and fanglength, to the type of prey taken; and in the relationship ofsnake shape and body proportions to the prey selected. Severalmodes of feeding have been observed among sea snakes: feedingin nooks and crannies in the bottom or in reefs, cruising nearthe bottom, and feeding in drift lines. Analysis of percentdigestion of stomach contents and projections backward to thetimes of prey capture provides evidence for feeding periodicity.The greatest amount of diet overlap is for two species of seasnakes which do not both occur at the same locality. Where speciesdo co-occur, diet overlap index values are lower. The numbersof species present as well as their relative abundances varyamong localities as does the relative importance of generalists,eel-eaters, egg-eaters and other specialized feeders.  相似文献   
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Pure samples of the antheridiogen of Anemia phyllitidis (AAn) were tested for their ability to affect the growth of dwarf corn (d5) and lettuce seedlings, and to influence α-amylase production by barley half-seeds. Stimulation of dwarf corn growth and barley amylase production was, on a molar basis, from 1/2 to 1/250 that given by GA3. In lettuce, AAn had a synergistic effect with low levels of GA3; alone, AAn was inhibitory or ineffective. Therefore, in addition to having a close chemical resemblance to gibberellin, AAn induces similar, but not identical physiological responses in flowering plants as well as ferns.  相似文献   
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Irisin was first identified in muscle cells. We detected irisin immunoreactivity in various organs of the crested porcupine (Hystrix cristata). In the epidermis, irisin immunoreactivity was localized mainly in stratum basale, stratum spinosum and stratum granulosum layers; immunoreactivity was not observed in the stratum corneum. In the dermis, irisin was found in the external and internal root sheath, cortex and medulla of hair follicles, and in sebaceous glands. Irisin immunoreactivity was found in the neural retina and skeletal muscle fibers associated with the eye. The pineal and thyroid glands also exhibited irisin immunoreactivity.  相似文献   
8.
A method is proposed for estimating the proportion of CO2 ofrespiration derived from the PPP and the TCAC by measuring thespecific activity of the respired CO2 and those of its precursorsin the tissue. In practice the specific activity of C-1 of G-6-Pand of the carboxyl carbon atoms of pyruvate and malate havebeen taken as the precursors. To apply this method there mustbe good evidence that these compounds are not in ‘pools’in the cell. In air in the sliced pea cotyledon 25–40% of the respiredCO2 arose from the PPP. In both 10% CO2 in air and in 2% O2 in N there was a showingin the rate of respiration and a large increase in the proportionof the CO2 deriving from the PPP. It is argued that in eachcase the cause of this was different. Key words: Carbon dioxide, Respiration, Pisum Sativum, Pentose-phosphate pathway  相似文献   
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Background

Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries. Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. The first successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.

Results

This study demonstrates that atypical scrapie has distinct clinical, pathological and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.

Conclusions

Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage.  相似文献   
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