Quaternary最新文献

{"title":"A Cryptotephra Layer in Sediments of an Infilled Maar Lake from the Eifel (Germany): First Evidence of Campanian Ignimbrite Ash Airfall in Central Europe","authors":"Fiona Schenk, U. Hambach, Sarah Britzius, D. Veres, F. Sirocko","doi":"10.3390/quat7020017","DOIUrl":"https://doi.org/10.3390/quat7020017","url":null,"abstract":"We analyzed mineralogical characteristics, and major as well as rare earth element concentrations, from a cryptotephra layer in sediments of the infilled maar of Auel (Eifel, Germany). The results of detailed geochemical analyses of clinopyroxenes and their glassy rims from the Auel cryptotephra layer showed that they are similar to those from the thick Campanian Ignimbrite tephra occurrence in a loess section at Urluia (Romania). Both tephras show idiomorphic green clinopyroxenes and formation of distorted grains up to millimeter scale. The cryptotephra in the Auel core has a modelled age of around 39,940 yr b2k in the ELSA-20 chronology, almost identical to the latest 40Ar/39Ar dates for the Campanian Ignimbrite/Y-5 (CI/Y-5) eruption. These observations suggest that parts of the CI/Y-5 ash cloud were transported also northwestward into Central Europe, whereas the main branch of the CI/Y-5 ash plume was transported from southern Italy towards the NE, E, and SE. Based on pollen analyses, we conclude there was no direct effect on vegetation from the CI/Y-5 fallout in the Eifel area. Trees, shrubs, and grasses remained at pre-tephra-airfall levels for roughly 240 years, but changed around 39,700 yr b2k when thermophilic woody plants (e.g., Alnus and Carpinus) disappeared and Artemisia spread. This change in vegetation was well after the Laschamp geomagnetic excursion and also after the GI9 interstadial and quite probably represents the onset of the Heinrich Event 4 (H4) cold spell, when climatic conditions over the North Atlantic, and apparently also in Central Europe, deteriorated sharply.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LOVE Is in the R—Two R Tools for Local Vegetation Reconstruction","authors":"M. Theuerkauf, J. Couwenberg","doi":"10.3390/quat7020018","DOIUrl":"https://doi.org/10.3390/quat7020018","url":null,"abstract":"Pollen deposition in small lakes and peatlands is composed of local pollen deposition arriving from the nearby vegetation and of regional pollen deposition arriving from farther away. The LOVE model aims to reconstruct past vegetation on a small local scale by extracting only the local pollen signal. To this end, pollen deposition from small sites is related to pollen deposition from large lakes with predominantly regional pollen deposition. We here present a new implementation of the LOVE model in the R environment for statistical computing that is more user friendly than existing implementations. It allows more readily application with fossil pollen data and facilitates extensive testing of the approach in simulated landscapes. The LOVE model derives from critical mathematical assumptions that strongly limit its application. We additionally present LOVEoptim as an adjusted approach to local-scale reconstructions. Other than in LOVE, past local plant abundances are approximated using numerical optimization. Tests in a simulated landscape, which is based on true landscape patterns from digital maps, show that both approaches are valid. Due to fewer mathematical assumptions, LOVEoptim is more widely applicable. The modeling results help to better interpret the spatial scale of vegetation reflected in LOVE/LOVEoptim reconstructions.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Middle Pleistocene Hippopotamus from Malagrotta (Latium, Italy): New Data and Future Perspectives","authors":"R. Martino, Fabrizio Marra, María Ríos, L. Pandolfi","doi":"10.3390/quat7010013","DOIUrl":"https://doi.org/10.3390/quat7010013","url":null,"abstract":"The Middle Pleistocene was characterized by the presence in continental Europe of at least two different species of hippopotamus: Hippopotamus antiquus and H. amphibius. Although suspected, the presence of both hippopotamuses in the same geographical area has not yet been proven. The following manuscript describes findings from Malagrotta (Rome, central Italy), dating back to the time span between 0.45 and 0.38 Ma. These findings offer new insights into the Middle Pleistocene period. The fragmented mandible has a slender and low corpus, the humerus is robust with a deltoid tuberosity placed medially on the diaphysis, the unciform shows a facet for the MCIV wider than the one for the MCV and the calcaneum is clepsydra-shaped. The morphological characteristics of the sample are closer to those of H. antiquus, despite the fact that the morphometric measurements are smaller than those of the samples coming from Valdarno (Italy), Untermaßfeld (Germany) or Colle Curti (Italy). Considering all the information, the material from Malagrotta is here attributed to H. cf. antiquus, indicating the survival of the European hippopotamus until at least 0.38 Ma in central Italy. The coexistence of H. amphibius and H. antiquus in the same geographical area is also discussed.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140411927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare Earth Elements in Sediments from the Laptev Sea Shelf: Insight into Sources and Distribution Factors","authors":"A. Ruban, O. Dudarev, M. Rudmin, I. Semiletov","doi":"10.3390/quat7010012","DOIUrl":"https://doi.org/10.3390/quat7010012","url":null,"abstract":"The study of rare earth elements (REEs) in marine sediments is a powerful geochemical tool for determining depositional processes and sediment provenance, as well as for understanding paleoenvironmental changes. In this context, we present REE, some major and trace elements, grain size, and mineralogy data on surface and core sediments, which were collected in different areas of the eastern Laptev Sea Shelf (LSS; Arctic Ocean). The primary objective of this paper was to assess the principal controlling factors influencing REE concentration and their vertical to lateral distribution. The total REE content (ΣREE) ranged from 139 ppm to 239 ppm within the studied sediment samples, predominantly consisting of silt. The normalized REE distribution patterns, based on North American Shale Composite (NASC) standard, exhibited an enrichment in light REE (LREE) when compared to heavy REE (HREE), which is similar to that in Lena River suspended particulate matter. The primary sources of REEs in the eastern LSS were both the suspended particulate matter from the Lena River and sediments originating from the coastal ice complex. The spatial distribution of REEs was primarily contingent upon the distance from sediment sources and prevailing hydrological conditions and was generally characterized by a decrease in REE concentration seaward. There was a moderate positive correlation between ΣREE and mean grain size in the studied surface sediment. However, this relationship was specific only for surface samples and was not found in the sediment cores, indicating that sediment grain size does not play a significant role in the REE vertical distribution. The strong positive correlation between ΣREE and Al, K, Ti, V, Cr, Zr, Hf, and Th suggests that REEs are hosted by not only heavy but also clay minerals. The vertical fluctuations of LREE/HREE, Eu/Eu*, (La/Lu)N can point at variable dominance of one or another REE source for during sediment accumulation.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140419014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Occurrence of Suids in the Post-Olduvai to Pre-Jaramillo Pleistocene of Europe and Implications for Late Villafranchian Biochronology and Faunal Dynamics","authors":"Alessio Iannucci","doi":"10.3390/quat7010011","DOIUrl":"https://doi.org/10.3390/quat7010011","url":null,"abstract":"It has been proposed that suids were absent from Europe during the post-Olduvai to pre-Jaramillo Early Pleistocene (from less than 1.8 to more than 1.2 Ma) and that their “re-appearance” in the late Early Pleistocene would mark the end of the late Villafranchian and the beginning of the Epivillafranchian. Arguments enumerated in favor of this “suid gap” are the lack of suid remains from extensively sampled fossil localities of this age and the high reproductive potential (r-strategy) of suids, which would translate in a high commonness of their remains in the fossil record. However, here it shown that while suids’ reproductive potential is certainly exceptional within artiodactyls, there is no direct relationship between the reproductive strategy and preservation rate of a taxon in the fossil record. In Early Pleistocene localities of Europe and adjoining areas, where suids are present in a fossil assemblage, they are always rare. In terms of number of occurrences (frequency), suids range from being moderately common (~2.0–1.8 Ma) to moderately rare (~1.1–1.0 Ma). Suid material is also described herein from Peyrolles (Issoire, France; reference locality for MNQ 19), a site dated at 1.47 Ma, providing direct evidence for the presence of suids within the purported “suid gap”. The case of suids underlines an important source of caveat in inferring faunal dynamics of the late Early Pleistocene of western Europe—including the dispersal of hominins—i.e., the unequal geographical distribution of the paleontological sites of post-Olduvai to pre-Jaramillo age. Indeed, Peyrolles is the only large mammal site in western Europe located outside the Iberian and Italian Peninsulas reliably dated around 1.5 Ma. In the post-Olduvai to pre-Jaramillo period, there is a paucity of radiometric estimates (or they have too coarse a resolution) and of paleomagnetic excursions detectable in continental deposits. Basically, for this time span, there is a high dependence on biochronological correlations, although, at the same time, these correlations are less reliable—because these are based on a few sites not covering the entire spectrum of environments present in Europe and the sites are not independently dated with methods that outperform biochronology—than those for other periods.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140445267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Quaternary Dynamics of Landscape and Climate in the North of the West Siberian Plain Revealed by Paleoecological Studies of Peat and Lake Sediments","authors":"Tatina Blyakharchuk, Nikita Shefer, Olga Ponomareva, Hong-Chun Li","doi":"10.3390/quat7010001","DOIUrl":"https://doi.org/10.3390/quat7010001","url":null,"abstract":"West Siberian mires covering more than 50% of area in the subarctic are still poorly investigated despite their thick peat sediments suitable for paleogeographic research of past long-term landscape and climatic changes. In this research, a combination of paleoecological methods were used, including the analysis of pollen, spores, diatoms, NPPs, and macrofossils, the measurement of peat humification, and quantitative paleoclimate reconstruction. This multi-proxy approach was applied to study a palsa bog (frost peat heave mound) located in the north of western Siberia on the border of the northern taiga and forest–tundra (65°18′56″ N, 72°52′27″ E). Chronology is based on 21 radiocarbon dates, which were calibrated in CLAM. Studies have shown that sediments of palsa bog Nadym of a 1050 cm thickness were formed both in the Holocene and earlier periods of the Quaternary. Radiocarbon dating worked well for peat sequences (610 cm thick), but failed for underlying lacustrine and mineral sediments (440 cm thick). Numerous remains of salt-water diatoms and exotic Neogene pollen were found in the lacustrine sediments (650–850 cm). The oldest sediments (850–1050 cm) have signs of secondary epicryogenic diagenesis in the form of cryogenic iron-enriched granules. Both lacustrine and bottom sediments contain abundant coniferous pollen. At the same time, spore–pollen complexes dated to the Last Glacial Age were not found in low sediments because of failed dates. To explain this, the authors turn to the hypothesis of glyacioisostatic compensation, according to which the study area was uplifted during the Last Glacial Age and the ancient deposits underwent secondary diagenesis in subaerial conditions. Holocene lacustrine sedimentation began to form about 9800 cal. a BP. These lacustrine sediments turned out to be enriched in redeposited Neogene pollen and diatoms. It was interpreted as an influence of excess humid climate in combination with geological subsidence of landscape in the study area during the Early Holocene. This caused lake formation and introduction of exotic microfossils via surface run-off from higher-relief areas in the catchment. Syngenetic sedimentation in the Nadym section is associated only with peat-mire deposits covering the last 8400 cal. a BP. For this time, the dynamic of vegetation cover and quantitative changes in paleoclimate were reconstructed using spore–pollen, macrofossil, humus, and NPP data as well as the information–statistical method of V.A. Klimanov. The spore–pollen analysis revealed four main phases in the development of vegetation cover: 1. Spruce–birch forests with open meadows and lakes (8400–7600 cal. a BP); 2. Dominance of spruce forests and thawed eutrophic (minerotrophic) mires (7600 to 6500 cal. a BP); 3. Coniferous–birch forests and thawed mesotrophic mires (6500 to 4500 cal. a BP); 4. Birch–pine forests and oligotrophic (ombrotrophic) bogs with permafrost mounds—palsa bogs (approx. the last 4500 years). Quantitati","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138945719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Latest Occurrence of Stephanorhinus hundsheimensis (Rhinocerotidae) in Europe: The Skeletons from the Cova del Rinoceront Site (Castelldefels, Barcelona)","authors":"David García-Fernández, E. Cerdeño, M. Sanz, Joan Daura","doi":"10.3390/quat6040060","DOIUrl":"https://doi.org/10.3390/quat6040060","url":null,"abstract":"New rhino remains recovered from Cova del Rinoceront (Castelldefels, Barcelona) confirm the presence of Stephanorhinus hundsheimensis (Toula, 1902) at the site and the taxon’s persistence until the late Middle–early Upper Pleistocene in Europe, that is, its latest documented occurrence. The three individuals recovered from the site are compared with specimens of other Pleistocene species, including those of S. hemitoechus, S. kirchbergensis and Coelodonta antiquitatis, but their anatomical characteristics (a long skull, moderate occipital elevation, partial nasal septum, and slender zygomatic arch) do not coincide with the latter’s documented features. Certain similarities are found with the most frequently occurring rhinocerotid at that time in the Iberian Peninsula, S. hemitoechus, but the cranial features of the latter differ. The anatomical characteristics of the Cova del Rinoceront individuals coincide most closely with those of S. hundsheimensis (i.e., a high occipital face, with rounded proximolateral angles and oblique lateral borders, as well as the frontoparietal angle, and facial development). Despite the marked overlaps in the general measurements of S. hundsheimensis and S. hemitoechus, many (cranial and postcranial) dimensions of the Cova del Rinoceront individuals coincide more closely with those of the former, although some bone proportions are more similar to those of the latter specimens. Therefore, S. kirchbergensis and C. antiquitatis can be discarded as they tend to be larger, more robust species.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139001369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quaternary Mammals from Central-Western Argentina in the Stratigraphic Context of Southern South America","authors":"E. Cerdeño, Natalia P. Lucero, J. Chiesa","doi":"10.3390/quat6040059","DOIUrl":"https://doi.org/10.3390/quat6040059","url":null,"abstract":"This is an updated contribution to the Quaternary geology and paleontology from central-western Argentina, focused on San Luis Province. It is mostly based on unpublished data; only some fossils had previously been briefly mentioned in broader faunal contexts. The fossil-bearing sediments correspond to eolian and alluvial environments of moderate energy, dominated by sands and sandy silts. They overlie high-energy fluvial cycles and underlie edaphic horizons. They have a wide distribution, and several radiocarbon dates allow their regional correlation. Stratigraphic sequences with the precise origin of fossils allow for the improvement of lithostratigraphic and faunal correlations with the Pampean Region (central and east Argentina; La Pampa and Buenos Aires provinces), where Pleistocene assemblages are better known, but also with central-western (Cuyo Region), northwestern, and northeastern Argentina. Faunal remains correspond to large mammals, represented by xenarthrans (Cingulata and Tardigrada), macraucheniids (Litopterna), gomphotheres (Proboscidea), and equids (Perissodactyla), a typical Pleistocene mixture of native (xenarthrans and litopterns) and immigrant mammals.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138604148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Past and Present Drivers of Karst Formation of Ciénega de El Mangle, Panama","authors":"J. Rivera-Solís, Adolfo Quesada-Román, Fran Domazetović","doi":"10.3390/quat6040058","DOIUrl":"https://doi.org/10.3390/quat6040058","url":null,"abstract":"Tropical coastal karst areas represent dynamic, fragile, and biodiverse environments. Central America’s karst regions have been scarcely studied, with most of the research focused on the northern part of the region and on several larger cave systems. The coastal carbonate zones of the Central American region represent a unique karstic landscape, which, so far, has been insufficiently studied. Therefore, in this paper, we aim to describe the (i) landscape geomorphology and (ii) chemical conditions that define Ciénega de El Mangle in Panama as a distinctive karstic site. Carried geomorphological mapping and the characterization of karstic features have resulted in the identification of the different karstic forms and processes that are present within this unique karstic area. Considering that the chosen karstic study area is located in a marine–coastal fringe on the periphery of a lagoon, it is affected by a combination of several factors and processes, including seawater intrusion (through sinkholes), the formation of conchiferous limestone (CaCO3), and NaCl precipitation related to efflorescence. Due to the seasonally humid tropical climate, the chemical weathering processes are intense, thus forming alkaline soils that are hindering the development of mangrove vegetation. The geomorphology of the area results from intense evaporation combined with an influx of brackish groundwater, due to which a landscape has evolved in the marine–coastal strips, of seasonal tropical climates, that exhibit saline beaches, known as a littoral shott. In total, 24 karstic microdolines have evolved within the shott, of which six represent domical geoforms formed by gradual evaporitic precipitation, while seven other geoforms represent active karstic sinkholes filled with brackish water. These results are key for understanding the past and present climate interactions and conditions that have led to the formation of tropical karst environments.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139211776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Fox from Bajiazui (Qingyang, Central China) and an Update on Early Pleistocene Foxes from China","authors":"Saverio Bartolini-Lucenti, Qigao Jiangzuo, Hao Jiang, Zhaoyu Li, Kun Xie, J. Madurell-Malapeira","doi":"10.3390/quat6040057","DOIUrl":"https://doi.org/10.3390/quat6040057","url":null,"abstract":"(1) Background: despite the fact that nowadays the genus Vulpes Frisch, 1775, is the most diverse among extant Canidae, its fossil record is utterly scarce, especially in the Asian Pliocene. The sparse nature of this record further complicates the reconstruction of the evolutionary scenario to fit these taxa with extant species. The situation seems to change slightly in the Early Pleistocene when two species are recorded: Vulpes alopecoides (Del Campana, 1913) in Europe and Vulpes chikushanensis, Young, 1930, in Asian localities. Unlike the former, which has an extensive record, the remains of the Chinese V. chikushanensis are sporadic and the validity of the taxon has also been questioned. (2) Methods: the study of the specimens from the Early Pleistocene site of Bajiazui (1.8–1.2 Ma, Qingyang, Gansu) in comparison to an extensive sample of Vulpes spp. The Pliocene–Early Pleistocene is relevant for the delimitation of fossil foxes variability; (3) Results: morphologically and morphometrically, the specimens of Bajiazui fit with the specimens of V. chikushanensis from other Chinese localities of the Early Pleistocene, e.g., Longdan (Gansu) and Huiyu (Fangshang), highlighting some difference with the latest Early Pleistocene forms of Jigushan fox; (4) Conclusions: the revision of the Asian fossil record of Vulpes is crucial in our attempt to understand and reconstruct the evolution of carnivoran guild during the late Early Pleistocene (1.8–0.8 Ma). The fox remains from Bajiazui, although fragmentary, add a valuable piece to our knowledge of V. chikushanensis, a species possibly strongly related to the extant Vulpes corsac (Linnaeus, 1768).","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139258111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}