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Adriana García Brian G. Jones Bryan E. Chenhalland Colin V. Murray-Wallace 《Alcheringa: An Australasian Journal of Paleontology》2013,37(4):507-518
The palaeobiota from a middle to late Holocene succession in Tom Thumbs Lagoon, N.S.W., Australia, reflects a range of environmental conditions caused by sea-level changes and active estuarine sedimentation. At the base of the succession (~ ?0.4 m AHD) a thin bed, containing molluscs dated at 6.7 ka B.P. by radiocarbon and amino acid racemisation, and foraminifers is indicative of open estuarine conditions. From +0.35 m AHD towards the top of the sequence the charophyte Lamprothamnium succinctum occurs in subrecent deposits. This species is characterised here by statistical measurements, and new characters are described and illustrated. The charophytes record a drop in sea level and the establishment of a lower salinity artificial wetland. The investigation has also established that decalcification in charophytes can be related to acidification produced by the release of organic acids, aggravated after 1928 by anthropogenic pollution. 相似文献
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An interdisciplinary approach involving analysis of plant macrofossils, pollen and soil micro morphology in combination with large-scale stripping of top soil, was applied in order to get a comprehensive understanding of pre-historic settlement, farming economy and land-use in Østfold, SE Norway. Investigations of 25 sites lead to two distinctive results: 1) A time-space perspective on usages of plants, and 2) Identification of agrarian activities in a relict field. Studies of these topics have hitherto been limited for this region. The results add fresh and essential knowledge to pre-historic times in Østfold and make a significant contribution to the understanding to these topics in neighbouring regions. 相似文献
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Zooarchaeologists have often employed studies of bone fracture morphology as a means of understanding past human cultural activity, and various methodological approaches have been developed for analyzing archaeological broken bone assemblages. It is widely understood that bones degrade over time, however, few studies have attempted to define and quantify the rate at which bones degrade and fracture morphologies change. This study examines degradation in frozen bones (−20 °C) and bones exposed to hot (40 °C) dry conditions. These two simulated environmental conditions represent extreme real-world climates, and allow for an actualistic understanding of the rates of degradation that bones experience in nature. When frozen, bones degrade slowly but significantly, and demonstrate measurable differences in samples frozen for 1, 10, 20, 40, and 60 weeks. In hot, dry conditions, bones degrade very quickly, and demonstrate measurable differences after 1, 3, 7, 14, and 21 days. These data allow for a more detailed understanding of the relationship between the cultural and natural processes that result in bone fracture, and the time period during which bones can be expected to maintain fresh fracture characteristics. This research also has implications for understanding human subsistence and survival strategies and for interpreting the archaeological record. 相似文献
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Nicholas J. Wade 《Journal of the history of the neurosciences》2013,22(1):26-28
At the end of the nineteenth century, Ludwig Edinger completed the first comparative survey of the microscopic anatomy of vertebrate brains. He is regarded as the founder of the field of comparative neuroanatomy. Modern commentators have misunderstood him to have espoused an anti-Darwinian linear view of brain evolution, harkening to the metaphysics of the scala naturae. This understanding arises, in part, from an increasingly contested view of nineteenth-century morphology in Germany. Edinger did espouse a progressionist, though not strictly linear, view of forebrain evolution, but his work also provided carefully documented evidence that brain stem structures vary in complexity independently from one another and across species in a manner that is not compatible with linear progress. This led Edinger to reject progressionism for all brain structures other than the forebrain roof, based on reasoning not too dissimilar from those his successors used to dismiss it for the forebrain roof. 相似文献
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城市形态学主要是指对城市的物质肌理、以及塑造其各种形式的人、社会经济和自然过程的研究。本文在对城市形态相关概念进行界定基础上,回顾了国外城市形态学的研究历程、三大主要流派的特点与成就,并以英、德、美、法等国当代城市形态学研究文献为基础,对该学科的当前进展进行了综述,最后提出我国相关研究存在的问题,以及国外城市形态研究所具有的重要启示与借鉴。 相似文献
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This essay sheds new light on the meaning and measurement of compactness—one of the most intriguing and least‐understood properties of geographic shapes. We articulate a unified theoretical foundation for the study of shape compactness that rests on two simple observations: First, that the circle is the most compact of shapes. And second, that there are 10—and possibly more—distinct geometrical properties of the circle that make it the most compact of shapes. We introduce these 10 properties, illustrate them with real‐world examples and define indices associated with these properties that can be calculated using a geographic information system. 相似文献
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《Interdisciplinary science reviews : ISR》2013,38(1):12-34
AbstractD’Arcy Thompson’s views on the forms of biomaterials are assessed in the light of current thinking on biomorphology in selected areas of biology. It is clear that his guiding concepts — that biological materials are structured in response to physical forces, and that the biological and abiotic realms share many common features — remain valid. Advances in the physical and biological sciences are discussed, from quantum mechanics and molecular biology to liquid crystalline materials and macroscopic forms. These reveal Thompson’s clear-sighted view of the role of physical and mathematical sciences in biology, as well as his blind-spots. 相似文献
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LI, Y.J., HAN, G., NEL, A. REN, D., PANG, H. & LIU. X.L., September 2012. A new fossil petalurid dragonfly (Odonata: Petaluroidea: Aktassiidae) from the Cretaceous of China. Alcheringa 36, 321–324. ISSN 0311-5518. The new petalurid species Pseudocymatophlebia boda is described from Lower Cretaceous strata of Inner Mongolia, China. It provides additional morphological characters for this genus, which has been previously recorded from the Lower Cretaceous of England. Together with Aktassia, it is the second aktassiid genus with a very wide distribution, even though this family remains known only from Eurasia. Furthermore, a new name, Brachaktassia gen. nov., is proposed to replace the brachiopod genus Aktassia Popov, 1976. 相似文献