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21.
We generally reviewed the distributions and potential risks of heavy metals, polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in the upper reaches of the Yangtze River based on recent studies. The distribution of heavy metals varied significantly with locations and types of mediums, and contents of some metals exceeded the limits in food. The contents of PAHs in the upper reaches of the Yangtze River were in line with those in the lower reaches. Low molecular weight PAHs were predominant in surface water, while high molecular weight PAHs were predominant in sediments, indicating low molecular PAHs may pose greater risks to aquatic ecosystems. DEHP and DBP were the predominant monomers of PAEs in surface water and sediments, and BBP and DBP ranked first and second respectively in fish bodies. The results of risk assessment also indicated that monomers such as DBP and DnBP had greater risk than DEHP. Over all, heavy metals and organic pollutants were widely distributed in the aquatic environment in the upper reaches of the Yangtze River, which may pose potential risks to the ecosystem. © 2019, Institute of Hydrobiology, Chinese Academy of Sciences. All rights reserved.  相似文献   
22.
《Palaeoworld》2022,31(1):69-85
The Devonian/Carboniferous (D/C) transition is characterized by a major transgressive/regressive cycle which led to a widespread ocean anoxia known as the Hangenberg Black Shale Event (HBSE), as well to a major sea-level fall (Hangenberg Sandstone Event, HSSE), recognized around the world. Both events are known as the Hangenberg Crisis. In order to examine the D/C transition in shallow water environment, the Mighan section in eastern Alborz was studied in terms of conodont biostratigraphy and stable isotope geochemistry. Twenty-five conodont species belonging to seven genera were identified and 5 conodont zones discriminated; namely, the Bispathodus aculeatus aculeatus Zone, Bispathodus costatus Zone, Bispathodus ultimus Zone, Siphonodella praesulcata Zone, costatus-kockeli Interregnum, and the sulcata Zone. Below the Devonian–Carboniferous boundary (DCB), the Hangenberg Black Shale and Hangenberg Sandstone equivalents were recognized, representing the Hangenberg Crisis that highly affected trilobite, ammonoid, brachiopod and conodont faunas at Mighan and worldwide. The kockeli Zone of the latest Famennian is missing at Mighan due to the lack of conodonts, probably related with the major environmental changes linked with the Hangenberg Crisis recognizable worldwide. Carbon isotopes measured of micrites from Mighan indicate a proximal depositional environment of a shallow shelf with terrestrial input and the oxygen isotope values from conodont apatite suggest warm seawater temperatures of tropical and subtropical setting in the study area.  相似文献   
23.
《L'Anthropologie》2019,123(2):345-402
The archaeological site of Eliseevichi 1, located in the Dnieper River Basin, was discovered in 1930 by K.M. Polikarpovich. It is contemporary of Epigravettian occupations of the end of the second half of the upper Pleniglacial (20,000–14,000 years BP). As for the sites of the culture of Mezine (Mezine, Mezhirich, Gontsy and Dobranitchevka), it was interpreted as a specialized camp of hunters, mainly for slaughtering woolly mammoths and fur exploitation. Moreover, mammoth bones have been used to build larger structures than in mezinian sites associated with storage pits, as in Timonovka I, Yudinovo, Yourevitchi, Suponevo and Chulatovo. However, Eliseevichi 1 differs from all other sites by the presence of ivory engraved pieces with zigzag patterns and multiple linear features and the presence of platelets with decorations in the form of fish scales (“churingas”) and the high number of chisels. These features make it a unique case in the Desna Valley. To better understand the activities that have been implemented within the site by human groups, particularly the role of different species, we processed to the zooarchaeological study of the faunal remains from the 1935–1936 excavations. The faunal spectrum is restricted, typical of a cold and dry environment, with Mammuthus primigenius, Rangifer tarandus, Canis lupus, Alopex lagopus rossicus and Ursus arctos. Two skulls were previously identified as being those of dogs. According to the taphonomical study we highlighted a quick and deep burying of bones, which were affected by freeze-thaw alternating, without being highly altered and moved by phenomena of cryoturbation. The woolly mammoth was used for its meat and for its ivory. The many remains of canids are characterized by skinning marks and long bones were sawed. The presence of ocher, ashy areas, crude lithic fragments, could be linked to the treatment of skins. The site of Eliseevichi 1 was probably occupied during winter and summer seasons, several times during a long period. It could have two main functions, not as a habitat but as a specialized site of furskin and bone production.  相似文献   
24.
《L'Anthropologie》2019,123(1):1-18
This paper reports the discovery of a new example of portable art in North-eastern Iberia dating to the Late Upper Palaeolithic (12.250 ± 60 BP). The piece is analysed in relation to the European Palaeolithic art assemblage to determine its significance and how it contributes to our understandings of Palaeolithic artistic practices. Both the motifs depicted (birds and humans) and the patterns of composition (a narrative scene) are unusual in Palaeolithic assemblages. In addition, this new find contributes to filling a geographic gap in the artistic record as evidence of Palaeolithic art is rare in Catalonia. The anatomical features of one of the birds suggest that it is a crane, a species that has been depicted in a limited number of sites, as summarized in this paper. Moreover, there are only three known example of birds and humans interacting in a narrative scene in Palaeolithic art. Exhibiting innovations in media, subject matter and compositional norms, this new find has the potential to change the classic definition of European Upper Palaeolithic art and integrate the region in the artistic trends circulating along Mediterranean Iberia during the Upper Magdalenian.  相似文献   
25.
《L'Anthropologie》2019,123(2):403-422
The Upper Palaeolithic site of Yudinovo is one of the reference sites, located in the Desna River Basin. Multidisciplinary field studies, organized by the Desna mission (MAE RAS) and conducted between 2004 and 2016, have changed the vision existed so far on the structure and character of the Yudinovo site as well as on the duration of its occupations. The researchers found an ancient ford used by mammoths and other big mammals to cross the river, and a water source was one of the main factors in explaining the location of the Yudinovo site. The site has been occupied in a cyclical way for stays of varied duration. It was frequented by Prehistoric Men during the different seasons, and periods of occupation were apparently of different duration. The stratigraphy of the Yudinovo site reveals two major episodes in the evolution of the site. The dating of the lower archaeological layer dates back to 15,000–13,500 BC. J.C., while the upper layer is attributed to the period of 12,500–12,000 BC. The lower layer, which was formed during the major episode of occupation of the site, is rather thin and shows the complex stratigraphic structure. Various areas of activities, evacuation structures, storage areas with mammoth bones are discovered. Some elements of the lower archaeological layer are perfectly correlated with different episodes of sporadic occupation.  相似文献   
26.
27.

Background

Upper arm development in children is different in different ethnic groups. There have been few reports on upper arm circumference (UAC) at different stages of development in children and adolescents in China. The purpose of this study was to provide a reference for growth with weighted assessment of the overall level of development.

Methods

Using a pooled analysis, an authoritative journal database search and reports of UAC, we created a new database on developmental measures in children. In conducting a weighted analysis, we compared reference values for 0~60 months of development according to the World Health Organization (WHO) statistics considering gender and nationality and used Z values as interval values for the second sampling to obtain an exponential smooth curve to analyze the mean, standard deviation, and sites of attachment.

Results

Ten articles were included in the pooled analysis, and these articles included participants from different areas of China. The point of intersection with the WHO curve was 3.5 years with higher values at earlier ages and lower values at older ages. Boys curve was steeper after puberty. The curves in the studies had a merged line compatible. The Z values of exponential smoothing showed the curves were similar for body weight and had a right normal distribution.

Conclusions

The integrated index of UAC in Chinese children and adolescents indicated slightly variations with regions. Exponential curve smoothing was suitable for assessment at different developmental stages.  相似文献   
28.
29.
Two radiolarian assemblages were recovered from upper Norian strata of the Kotel’nyi Island (Russia); the first assemblage, from the Monotis zabaikalica Subzone (lower part of Upper Norian), is represented by Betraccium inornatum Blome, Dumitricaella (?) parva Sugiyama, Ferresium titulense Blome and 24 other species; the second assemblage, from the Monotis subcircularis Subzone (upper part of Upper Norian), is represented by Crucella sp. cf. C. angulosa Carter, Kahlerosphaera acris Bragin, K. sp. cf. K. parvispinosa Kozur & Mostler, Pseudohagiastrum crassum (Carter) and 11 other species. Both assemblages have common taxa with Upper Norian and Rhaetian radiolarian assemblages of British Columbia and they display clear Boreal features: low taxonomic diversity, abundance of taxa known from high-latitude regions, absence or rare presence of taxa known from low-latitude areas. The presence of early representatives of nassellarian genera Droltus and Parahsuum is very distinctive. Six new species are described: Pseudohagiastrum spinosum nov. sp., Cantalum boreale nov. sp., Plafkerium carteri nov. sp., Droltus guttaeformis nov. sp., Laxtorum blomei nov. sp., L. glacialis nov. sp.  相似文献   
30.
We present the rationale for a cross‐disciplinary investigation addressing the ‘Devonian plant hypothesis’ which proposes that the evolutionary appearance of trees with deep, complex rooting systems represents one of the major biotic feedbacks on geochemical carbon cycling during the Phanerozoic. According to this hypothesis, trees have dramatically enhanced mineral weathering driving an increased flux of Ca2+ to the oceans and, ultimately, a 90% decline in atmospheric CO2 levels through the Palaeozoic. Furthermore, experimental studies indicate a key role for arbuscular mycorrhizal fungi in soil–plant processes and especially in unlocking the limiting nutrient phosphorus in soil via Ca‐phosphate dissolution mineral weathering. This suggests co‐evolution of roots and symbiotic fungi since the Early Devonian could well have triggered positive feedbacks on weathering rates whereby root–fungal P release supports higher biomass forested ecosystems. Long‐standing areas of uncertainty in this paradigm include the following: (1) limited fossil record documenting the origin and timeline of the evolution of tree‐sized plants through the Devonian; and (2) the effects of the evolutionary advance of trees and their in situ rooting structures on palaeosol geochemistry. We are addressing these issues by integrating palaeobotanical studies with geochemical and mineralogical analyses of palaeosol sequences at selected sites across eastern North America with a particular focus on drill cores from Middle Devonian forests in Greene County, New York State.  相似文献   
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