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Artur Chahud Gisele Ferreira Figueiredo Gabriela Sartori Mingatos Mercedes Okumura 《第四纪科学杂志》2021,36(7):1268-1278
The Lapa do Santo archaeological site, located in the Lagoa Santa region, Brazil, represents an important hunter-gatherer occupation dated from the Early and Middle Holocene. Prior studies of archaeofauna dating to this period are few and most of them only provide basic faunal identification with limited information on taphonomic processes. The main goal of this study is to identify the archaeofauna, record the taphonomic processes, and make inferences about its natural (interpreted as the death of the animal in the rockshelter area due to natural causes or due to predation) or anthropic origins. No extinct species (including megamastofauna) were identified. Taxonomic analysis indicated that most faunal remains consist of taxa that may be of mixed origin (natural or anthropic), such as microvertebrates and carnivorous mammals. The Cervidae are the main vertebrate family found in the studied material and these are likely the result of hunting. The Cervidae Ozotoceros support the presence of a fauna that is typical of savannah environments, although the assemblage contains mostly generalist fauna that can thrive in a variety of environments. Very few remains showed clear evidence for taphonomic processes related to human interaction, such as burnt bones. 相似文献
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Filho Hugo Carlos Scheuermann Martins Carlos Guilherme Menezes Ricardo José Wink Dornelles Lucas Eduardo Consoli Nilo Cesar 《Geotechnical and Geological Engineering》2021,39(7):5395-5404
Geotechnical and Geological Engineering - Dispersive soils are susceptible to phenomena of internal and external erosion when in contact with relatively pure water due to its particle’s... 相似文献
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da Silva Fabricio Polifke da Silva Alfredo Silveira da Silva Maria Gertrudes Alvarez Justi Pires Gisele Dornelles 《Natural Hazards》2022,110(1):695-718
Natural Hazards - The ability to forecast extreme precipitation events has become increasingly important over the last decades due to their significant impacts on society and properties. In this... 相似文献
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Marcelo Accioly Teixeira de Oliveira Jorge Luis Porsani Gisele Leite de Lima Vivian Jeske-Pieruschka Hermann Behling 《Quaternary Research》2012,77(3):397-407
Paleoenvironmental interpretation of proxy data derived from peatlands is largely based upon an evolutionary model for ombrotrophic bogs, in which peat accumulates in still environments. Reports on proxies obtained from minerotrophic fens, where hydrologic inputs are variable, are less common. In this study, a highland peatland in southern Brazil is presented through ground penetrating radar (GPR) and sedimentological, palynological and geochronologic data. The radar stratigraphic interpretation suggests a relatively complex history of erosion and deposition at the site since the beginning of Marine Isotope Stage 3 (MIS 3) interstadial period. In spite of this, radar stratigraphic and palynologic interpretations converge. Electromagnetic reflections tend to group in clusters that show lateral coherence and correlate with different sediment types, while pollen grains abound and are well preserved. As a result, the study of minerotrophic fens provides a source of proxies, suggesting that ombrotrophic bogs are not the only reliable source of data in wetlands for palynological analysis. 相似文献
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The effect of temperature‐humidity similarity on Bowen ratios,dimensionless standard deviations,and mass transfer coefficients over a lake 
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下载免费PDF全文 Similarity between heat and water vapor turbulent transport in the Atmospheric Surface Layer has been the basis of many engineering models to calculate surface fluxes, including the widely applied Bowen ratio equation, for a long time. Modernly, it is best understood within the context of Monin‐Obkhov Similarity Theory (MOST). In this work we study similarity between temperature and humidity, the Bowen ratio, and turbulent mass and heat transfer coefficients over a tropical lake in Brazil (Furnas Lake). The analysis was partly based on the concept of ‘Surface flux numbers’ recently proposed to diagnose scalar similarity, and considered wind directions and flux footprints. A period of 50 days of 30‐min. micrometeorological runs was used. Several cases of dissimilar temperature‐humidity behavior were found in the data. Both footprint extent and an aggregate temperature‐humidity Surface flux number turned out to be insufficient to diagnose these situations, but separate flux numbers for each scalar were able to diagnose their individual conformity to MOST. Overall, temperature displayed consistently larger relative variances and fluxes in comparison with humidity. The results highlight the need of careful analysis when measurements are made at sites close to land, when flux footprints may extend over there, indicating the possibility of advection effects. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Clodoveu A. Davis Jr. Gisele L. Pappa Diogo Rennó Rocha de Oliveira Filipe de L. Arcanjo 《Transactions in GIS》2011,15(6):735-751
User interaction in social networks, such as Twitter and Facebook, is increasingly becoming a source of useful information on daily events. The online monitoring of short messages posted in such networks often provides insight on the repercussions of events of several different natures, such as (in the recent past) the earthquake and tsunami in Japan, the royal wedding in Britain and the death of Osama bin Laden. Studying the origins and the propagation of messages regarding such topics helps social scientists in their quest for improving the current understanding of human relationships and interactions. However, the actual location associated to a tweet or to a Facebook message can be rather uncertain. Some tweets are posted with an automatically determined location (from an IP address), or with a user‐informed location, both in text form, usually the name of a city. We observe that most Twitter users opt not to publish their location, and many do so in a cryptic way, mentioning non‐existing places or providing less specific place names (such as “Brazil”). In this article, we focus on the problem of enriching the location of tweets using alternative data, particularly the social relationships between Twitter users. Our strategy involves recursively expanding the network of locatable users using following‐follower relationships. Verification is achieved using cross‐validation techniques, in which the location of a fraction of the users with known locations is used to determine the location of the others, thus allowing us to compare the actual location to the inferred one and verify the quality of the estimation. With an estimate of the precision of the method, it can then be applied to locationless tweets. Our intention is to infer the location of as many users as possible, in order to increase the number of tweets that can be used in spatial analyses of social phenomena. The article demonstrates the feasibility of our approach using a dataset comprising tweets that mention keywords related to dengue fever, increasing by 45% the number of locatable tweets. 相似文献
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Sipunculan taxonomy relies on a limited set of external morphological and internal anatomical characters. In addition, this marine group is characterized by an unusual large number of putatively cosmopolitan species. However, this ‘cosmopolitan’ status could be an artifact of their conserved morphology and the small number of unambiguous taxonomic characters available for delimiting species. Species delimitation can therefore be aided by molecular techniques. We investigated the case of the widespread and common species Sipunculus nudus Linnaeus, 1766 to determine its systematic validity. We analysed the morphology of multiple specimens of S. nudus collected from 11 localities around the world and undertook phylogenetic analyses using molecular sequence data from four genes (28S rRNA, 16S rRNA, histone H3 and cytochrome c oxidase subunit I). High levels of genetic differentiation are present between distantly related populations of the putative species S. nudus. Five distinct lineages were identified by phylogenetic analyses, three of which – the best‐represented populations – can be distinguished morphologically. Our phylogenetic and morphological analyses thus do not favor the cosmopolitan status of S. nudus, suggesting instead that it constitutes a complex of morphologically similar but distinguishable species. 相似文献
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