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Marine biology and biological oceanography are two disciplinary subfields that have long struggled with their definitions. Should marine biology simply be considered a part of biology that takes place in the marine environment or is it a distinct entity, with conceptual problems and methodological approaches all its own? Similarly, biological oceanography could be seen as a necessary adjunct to physical and chemical oceanography or it could be defined more as an extension of biology into the marine realm. In the United States, these issues were directly addressed from the mid 1950s through the mid 1960s in a series of events that shed light on how marine biologists came to a working definition of their field that provided a broad methodological tent for practitioners and, at the same time, allied the field to oceanography during a period in which exploration of uncharted areas drew considerable funding from the post-WWII federal agencies charged with keeping American science at the forefront.  相似文献   

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Results are presented from archaeobotanical analyses carried out in ‘The Mirror Pit’, a rectangular pit, situated in the city of Ferrara, in Emilia Romagna—Northern Italy. The study is part of wider research focused on the Mediaeval period of this city. The pit belongs to a building which was in use from the second half of 14th to the end of 15th century a.d. The pit itself was filled with domestic rubbish during a few years in the middle of the 15th century. The layers were preserved by waterlogging and are therefore extraordinarily rich in organic remains and artifacts, among which was the beautiful spherical mirror which gave its name to the pit. Approximately 256,000 well-preserved seeds and fruits belonging to 98 species or carpological types were identified in 12 l of sediment from the different layers. Ficus carica, Brassica rapa subsp. rapa/subsp. sylvestris and Vitis vinifera subsp. vinifera prevailed. Many cultivated plants and weeds were present, together with a smaller number of wild plants of wet environments and woodlands. Altogether they provided much new information on the diet (cultivated and wild fruits, cereals and pulses, vegetables, spices and medicinal/fibre/oil plants) of the middle to upper class inhabitants of a city in Northern Italy during the Renaissance period. The records also yielded evidence of domestic activities such as winemaking, oil making, mustard making and other kitchen practices.  相似文献   

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Macroscopic charred remains of Spinacia oleracea L. (Amaranthaceae) have been found in the Pyrenean village of Montaillou, France, in several contexts of a house dated to the end 12th–mid 13th century a.d. This is the first archaeobotanical record of this vegetable in France and the earliest European archaeobotanical material so far found. The paper presents the morphological criteria used for identifying the charred remains of the species. After a review of archaeobotanical finds in Europe, hypotheses on the economic status of this vegetable, which is unknown as a wild plant in Europe, are discussed with reference to medieval written and illuminated sources and to archaeological deposits. It appears that Spinacia was first introduced into France from Moorish Spain where it was cultivated at least since the 11th century. The French evidence of Spinacia thus represents a milestone in the history and geographic diffusion of this vegetable into temperate Europe.  相似文献   

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On April 17-18th 2013,the 4th meeting of the Mérieux Chinese Research Network was held in Wuhan,an event organized by Institut Mérieux,together with the Wuhan Institute of Virology,Chinese Academy of Sciences,Huangzhong University of Science and Technology,and the Chinese Society for Microbiology.  相似文献   

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This paper was written in honor of Dr. Noriyuki Satoh who was awarded A.O. Kowalewsky medal, an international prize of the St. Petersburg Society of Naturalists. We congratulate and thank this eminent zoologist for his outstanding scientific achievements, for his life’s work in the discipline founded by A.O. Kowalewsky. Published in Russian in Ontogenez, 2006, Vol. 37, No. 6, pp. 474–477. The text was submitted by the authors in English.  相似文献   

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The concept of pilot pseudopodia is reconsidered 30 years after its inauguration (Gerisch, G., Hülser, D., Malchow, D., Wick, U., 1975. Cell communication by periodic cyclic-AMP pulses. Phil. Trans. R. Soc. Lond. B 272, 181-192). The original hypothesis stated that protruding pseudopodia serve as dynamic sensory organelles that aid a cell in perceiving variations of chemoattractant concentration and, consequently, in navigation during chemotaxis. This influential idea is reevaluated in the light of recent findings about the mechanisms governing chemotactic cell motility, morphology and dynamics of pseudopodia, and about molecular constituents and regulators of pseudopod extension and retraction. It is proposed that stimulation by a chemoattractant modulates speed of pseudopod protrusion and thereby increases cell elongation. Elongation further enhances chemotactic sensitivity of the cell to shallow chemoattractant gradients, reinforces cell polarization, and finally leads to suppression of lateral pseudopodia and continuation of cell migration in the gradient direction.  相似文献   

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The names of organisms have major impacts on the geopolitical world. The current state of flux in the taxonomy of the genera Cryptosporidium and Giardia illustrates the effects that names can have on environmental and governmental policy. Taxonomy remains a vital science that is very much alive in the application of modern methods for describing morphologically cryptic species.  相似文献   

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The complete sequence of rice centromere 8 reveals a small amount of centromere-specific satellite sequence in blocks interrupted by retrotransposons and other repetitive DNA, in an arrangement that is strikingly similar in overall size and content to other centromeres of multicellular eukaryotes.  相似文献   

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Have you ever wondered why professionals have so many complicated names for things? Two reasons come to mind: efficient communication, but also 'show'. Connecting with a wider audience means learning to tread the fine line between perfect accuracy and being understood.  相似文献   

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The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to 'step' increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement. We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman's correlation was used to relate site stress to growth-rate changes. Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates. Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions.  相似文献   

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