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Sample records for early late pleistocene

  1. Late Pleistocene climate drivers of early human migration

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    Timmermann, Axel; Friedrich, Tobias

    2016-10-01

    On the basis of fossil and archaeological data it has been hypothesized that the exodus of Homo sapiens out of Africa and into Eurasia between ~50-120 thousand years ago occurred in several orbitally paced migration episodes. Crossing vegetated pluvial corridors from northeastern Africa into the Arabian Peninsula and the Levant and expanding further into Eurasia, Australia and the Americas, early H. sapiens experienced massive time-varying climate and sea level conditions on a variety of timescales. Hitherto it has remained difficult to quantify the effect of glacial- and millennial-scale climate variability on early human dispersal and evolution. Here we present results from a numerical human dispersal model, which is forced by spatiotemporal estimates of climate and sea level changes over the past 125 thousand years. The model simulates the overall dispersal of H. sapiens in close agreement with archaeological and fossil data and features prominent glacial migration waves across the Arabian Peninsula and the Levant region around 106-94, 89-73, 59-47 and 45-29 thousand years ago. The findings document that orbital-scale global climate swings played a key role in shaping Late Pleistocene global population distributions, whereas millennial-scale abrupt climate changes, associated with Dansgaard-Oeschger events, had a more limited regional effect.

  2. Hominin teeth from the early Late Pleistocene site of Xujiayao, Northern China.

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    Xing, Song; Martinón-Torres, María; Bermúdez de Castro, Jose María; Wu, Xiujie; Liu, Wu

    2015-02-01

    It is generally accepted that from the late Middle to the early Late Pleistocene (∼340-90 ka BP), Neanderthals were occupying Europe and Western Asia, whereas anatomically modern humans were present in the African continent. In contrast, the paucity of hominin fossil evidence from East Asia from this period impedes a complete evolutionary picture of the genus Homo, as well as assessment of the possible contribution of or interaction with Asian hominins in the evolution of Homo sapiens and Homo neanderthalensis. Here we present a comparative study of a hominin dental sample recovered from the Xujiayao site, in Northern China, attributed to the early Late Pleistocene (MIS 5 to 4). Our dental study reveals a mosaic of primitive and derived dental features for the Xujiayao hominins that can be summarized as follows: i) they are different from archaic and recent modern humans, ii) they present some features that are common but not exclusive to the Neanderthal lineage, and iii) they retain some primitive conformations classically found in East Asian Early and Middle Pleistocene hominins despite their young geological age. Thus, our study evinces the existence in China of a population of unclear taxonomic status with regard to other contemporary populations such as H. sapiens and H. neanderthalensis. The morphological and metric studies of the Xujiayao teeth expand the variability known for early Late Pleistocene hominin fossils and suggest the possibility that a primitive hominin lineage may have survived late into the Late Pleistocene in China. Copyright © 2014 Wiley Periodicals, Inc.

  3. Early human symbolic behavior in the Late Pleistocene of Wallacea

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    Brumm, Adam; Hakim, Budianto; Ramli, Muhammad; Sumantri, Iwan; Burhan, Basran; Saiful, Andi Muhammad; Siagian, Linda; Suryatman; Sardi, Ratno; Jusdi, Andi; Abdullah; Mubarak, Andi Pampang; Hasliana; Hasrianti; Oktaviana, Adhi Agus; Adhityatama, Shinatria; van den Bergh, Gerrit D.; Aubert, Maxime; Zhao, Jian-xin; Huntley, Jillian; Li, Bo; Roberts, Richard G.; Saptomo, E. Wahyu; Perston, Yinika; Grün, Rainer

    2017-01-01

    Wallacea, the zone of oceanic islands separating the continental regions of Southeast Asia and Australia, has yielded sparse evidence for the symbolic culture of early modern humans. Here we report evidence for symbolic activity 30,000–22,000 y ago at Leang Bulu Bettue, a cave and rock-shelter site on the Wallacean island of Sulawesi. We describe hitherto undocumented practices of personal ornamentation and portable art, alongside evidence for pigment processing and use in deposits that are the same age as dated rock art in the surrounding karst region. Previously, assemblages of multiple and diverse types of Pleistocene “symbolic” artifacts were entirely unknown from this region. The Leang Bulu Bettue assemblage provides insight into the complexity and diversification of modern human culture during a key period in the global dispersal of our species. It also shows that early inhabitants of Sulawesi fashioned ornaments from body parts of endemic animals, suggesting modern humans integrated exotic faunas and other novel resources into their symbolic world as they colonized the biogeographically unique regions southeast of continental Eurasia. PMID:28373568

  4. Continuity versus discontinuity of the human settlement of Europe between the late Early Pleistocene and the early Middle Pleistocene. The mandibular evidence

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    Bermúdez de Castro, José María; Martinón-Torres, María; Rosell, Jordi; Blasco, Ruth; Arsuaga, Juan Luís; Carbonell, Eudald

    2016-12-01

    One of the most interesting aspects of the settlement of Europe is the possible continuity or discontinuity of the populations living in this continent during the Early and Middle Pleistocene. In this paper we present an analysis of the mandibular fossil record from four important Pleistocene European sites, Gran Dolina-TD6-2 (Sierra de Atapuerca), Mauer, Arago, and Atapuerca-Sima de los Huesos. We focus this study in the recognition of key derived mandibular features that may be useful to assess the relationship among the populations represented at these sites. In order to make an approach to the ecological scenario, we also present a short review and discussion of the archaeological and paleoenvironmental evidences at that time. Our results suggest that probably there was a demographic discontinuity between the late Early Pleistocene populations (MIS 21-MIS 19), and those dated to the MIS 15. Hybridization between residents and new settlers cannot be discarded. However, some features of the Gran Dolina-TD6 hominins point to some relationship between the population represented in this site (probably dated to the MIS 21) and the European Middle Pleistocene and early Late Pleistocene populations. A hypothetical scenario is presented in order to understand this apparent contradiction with the model of discontinuity.

  5. Paleosoils and pedogenic calcretes formations in Fray Bentos (Oligocene - early miocene) Raigon (late pliocene and middle pleistocene) and Libertad (early - middle pleistocene)

    International Nuclear Information System (INIS)

    Tofalo, O.; Morras, H.; Sanchez-Bettucci, L.

    2012-01-01

    The Fray Bentos formation is composed by loessic deposits based on paleosoils and pedogenic calcretes (Oligocene - early miocene). In this deposits are tubular and lamellar formations which would have been formed in arid climates.The fluvial origen of Raigon Formation, (late pliocene and middle pleistocene) presents a paleosoil roof which is generated under a subhumid climate.The Libertad Formation during the glacial intervals consisted of loess deposits

  6. Dietary traits of the late Early Pleistocene Bison menneri (Bovidae, Mammalia) from its type site Untermassfeld (Central Germany) and the problem of Pleistocene 'wood bison'

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    van Asperen, Eline N.; Kahlke, Ralf-Dietrich

    2017-12-01

    Over the course of the Early and early Middle Pleistocene, a climatic cooling trend led to the partial opening up of landscapes in the western Palaearctic. This led to a gradual replacement of browsers by grazers, whilst some herbivore species shifted their diet towards including more grass. Wear patterns of herbivore cheek teeth can inform our understanding of the timing and extent of this change and indicate levels of dietary plasticity. One of the indicator species of the faunal turnover is the first large-sized form of bison in the Palaearctic, Bison menneri. The dental mesowear of the palaeopopulation from the species' late Early Pleistocene type site of Untermassfeld in Central Germany and the Late Pleistocene B. priscus from Taubach, both from habitat mosaics of forested habitats and more open landscapes, have a mixed feeder profile similar to that of North American wood bison, which has a distinct preference for open habitats but occasionally consumes a high amount of browse as a fall-back food. In contrast, the grazer mesowear signature of early Middle Pleistocene B. schoetensacki voigtstedtensis from Voigtstedt indicates these animals likely did not regularly feed in the densely forested area around the site. The mesowear of B. schoetensacki from Süssenborn, in a more open environment, is similar to that of extant European bison. Both Pleistocene and extant bison are grazers to mixed feeders with relatively high tolerance of a suboptimal browsing diet. None of these species can be regarded as true 'wood bison'.

  7. Preliminary Study of Late Pleistocene to Early Holocene Plant Food Strategies in China

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    Hayashi Tang, M.; Liu, X.; Fritz, G.; Zhao, Z.

    2017-12-01

    In recent decades, studies on the domestication and early cultivation of seed crops have contributed significantly to how we understand human-plant interactions, and their impact on human social organisation and the environment. It is becoming clear, however, that plants have been critical to the human diet for much longer and in more diverse ways than previously assumed. This paper is a preliminary attempt at identifying and addressing early prehistoric plant food strategies in China. In particular, very little is known about the use of vegetatively propagated plants, despite their significant representation in modern crops. Many ingredients of Chinese medicine are also roots and tubers (or vegetative storage organs, VSOs). Unlike seed crops, however, we lack a systematic criterion for examining diagnostic characters of different VSO taxa in the archaeological record. To address this issue, we characterized commonly consumed and historically significant VSOs in China, by studying experimentally charred modern samples under the optical microscope and scanning electron microscope. We then compared the characteristics of these modern VSO samples against plant remains from Late Pleistocene to early Holocene archaeological sites in China, such as Zengpiyan (Guangxi), Zhaoguodong (Guizhou), and Jiahu (Henan) sites. We found that different taxa of VSOs can be differentiated by using multiple lines of evidence, including: shape and size of various cells, texture and arrangement of cell walls, as well as anatomical arrangements of organs, especially the vascular bundles. Though identification can be difficult when fragile cell structures have collapsed or deteriorated, more robust features are often preserved for diagnosis. Our results suggest that the potential for studying the role of vegetatively propagated plants in early human-environmental interactions is overlooked, and can be expanded significantly with further investment in their systematic identification.

  8. Late Pleistocene to early Holocene environmental changes on Store Koldewey, coastal north-east Greenland

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    Martin Klug

    2016-12-01

    Full Text Available A lake sediment sequence from southern Store Koldewey, north-east Greenland, has been investigated using a multidisciplinary approach, including geophysical, geochemical, biogeochemical, biological and sedimentological methods. Chronological constraints are provided by accelerator mass spectrometry (AMS 14C dating of bulk sediment and complemented with published water moss ages. The record consists of three major sediment units. Their individual structural, textural, geophysical and geochemical characteristics indicate variable input of sediment and meltwater due to variable proximity of the ice margin and therefore reflect the growth and decay of a local glacier during the late Weichselian. Radiocarbon dating of bulk sediment samples from the lowermost unit gave ages of 42 to 34 calibrated thousand years (cal Ky B.P. and indicates that this material is redeposited in the lake basin during or after the ice advance at the end of the Pleistocene. Increased meltwater and sediment input from a retreating ice margin following the Younger Dryas is indicated by the occurrence of a sandy to gravely section. Fine-grained and laminated sediments were deposited during the Pleistocene–Holocene transition and indicate calm sedimentation conditions with an ice margin outside of the lake catchment. The reoccurrence of coarse sediments during the early Holocene may indicate increased meltwater input in response to the cold spell at about 9.3 Kya with increased snow accumulation rather than fluctuations of local glaciers. The dating results furthermore show that AMS 14C dating of bulk sediment samples deposited during glacier decay in High Arctic environments can give problematic ages.

  9. Late Pleistocene and Early Holocene Rock Art from the Mongolian Altai: The Material and its Cultural Implications

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    Esther Jacobson-Tepfer

    2013-09-01

    Full Text Available Rock-pecked images from the northern Mongolian Altai attest to the presence of human communities within the high valleys of that region during the Late Pleistocene and Early Holocene. The material provides evidence that is hitherto largely missing from the archaeological record of that region. This paper reviews the rock art, its find sites and larger physical contexts and uses evidence from paleoenvironmental studies to propose dating and cultural significance. The material is compared with other sites said to have Paleolithic imagery from Mongolia and the adjoining Russian Altai. The body of presented material offers a major resource for the study of early hunter-gatherer communities at the interface of Central and North Asia.

  10. A reassessment of the early archaeological record at Leang Burung 2, a Late Pleistocene rock-shelter site on the Indonesian island of Sulawesi

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    Brumm, Adam; Hakim, Budianto; Ramli, Muhammad; Aubert, Maxime; van den Bergh, Gerrit D.; Li, Bo; Burhan, Basran; Saiful, Andi Muhammad; Siagian, Linda; Sardi, Ratno; Jusdi, Andi; Said, Abdullah; Mubarak, Andi Pampang; Moore, Mark W.; Roberts, Richard G.; Zhao, Jian-xin; McGahan, David; Jones, Brian G.; Perston, Yinika; Szabó, Katherine; Mahmud, M. Irfan; Westaway, Kira; [Unknown], Jatmiko; Saptomo, E. Wahyu; van der Kaars, Sander; Grün, Rainer; Wood, Rachel; Dodson, John; Morwood, Michael J.

    2018-01-01

    This paper presents a reassessment of the archaeological record at Leang Burung 2, a key early human occupation site in the Late Pleistocene of Southeast Asia. Excavated originally by Ian Glover in 1975, this limestone rock-shelter in the Maros karsts of Sulawesi, Indonesia, has long held

  11. Using provenance of terrigenous sediment to reconstruct the Agulhas Leakage during the Early and Late Pleistocene

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    Pearson, B.; Franzese, A. M.

    2017-12-01

    instance, for the Early Pleistocene ( 1.3 - 1.5 Ma), K-Ar model ages correlate with shipboard measurements of natural gamma radiation, which show approximate 41 kyr periodicity.

  12. Liquefaction along Late Pleistocene to early Holocene Faults as Revealed by Lidar in Northwest Tasmania, Australia

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    Webb, J.; Gardner, T.

    2016-12-01

    In northwest Tasmania well-preserved mid-Holocene beach ridges with maximum radiocarbon ages of 5.25 ka occur along the coast; inland are a parallel set of lower relief beach ridges of probable MIS 5e age. The latter are cut by northeast-striking faults clearly visible on LIDAR images, with a maximum vertical displacement (evident as difference in topographic elevation) of 3 m. Also distinct on the LIDAR images are large sand boils along the fault lines; they are up to 5 m in diameter and 2-3 m high and mostly occur on the hanging wall close to the fault traces. Without LIDAR it would have been almost impossible to distinguish either the fault scarps or the sand boils. Excavations through the sand boils show that they are massive, with no internal structure, suggesting that they formed in a single event. They are composed of well-sorted, very fine white sand, identical to the sand in the underlying beach ridges. The sand boils overlie a peaty paleosol; this formed in the tea-tree swamp that formerly covered the area, and has been offset along the faults. Radiocarbon dating of the buried organic-rich paleosol gave ages of 14.8-7.2 ka, suggesting that the faulting is latest Pleistocene to early Holocene in age; it occurred prior to deposition of the mid-Holocene beach ridges, which are not offset. The beach ridge sediments are up to 7 m thick and contain an iron-cemented hard pan 1-3 m below the surface. The water table is very shallow and close to the ground surface, so the sands of the beach ridges are mostly saturated. During faulting these sands experienced extensive liquefaction. The resulting sand boils rose to a substantial height of 2-3 m, probably possibly reflecting the elevation of the potentiometric surface within the confined part of the beach ridge sediments below the iron-cemented hard pan. Motion on the faults was predominantly dip slip (shown by an absence of horizontal offset) and probably reverse, which is consistent with the present-day northwest

  13. Simple technologies and diverse food strategies of the Late Pleistocene and Early Holocene at Huaca Prieta, Coastal Peru.

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    Dillehay, Tom D; Goodbred, Steve; Pino, Mario; Vásquez Sánchez, Víctor F; Tham, Teresa Rosales; Adovasio, James; Collins, Michael B; Netherly, Patricia J; Hastorf, Christine A; Chiou, Katherine L; Piperno, Dolores; Rey, Isabel; Velchoff, Nancy

    2017-05-01

    Simple pebble tools, ephemeral cultural features, and the remains of maritime and terrestrial foods are present in undisturbed Late Pleistocene and Early Holocene deposits underneath a large human-made mound at Huaca Prieta and nearby sites on the Pacific coast of northern Peru. Radiocarbon ages indicate an intermittent human presence dated between ~15,000 and 8000 calendar years ago before the mound was built. The absence of fishhooks, harpoons, and bifacial stone tools suggests that technologies of gathering, trapping, clubbing, and exchange were used primarily to procure food resources along the shoreline and in estuarine wetlands and distant mountains. The stone artifacts are minimally worked unifacial stone tools characteristic of several areas of South America. Remains of avocado, bean, and possibly cultivated squash and chile pepper are also present, suggesting human transport and consumption. Our new findings emphasize an early coastal lifeway of diverse food procurement strategies that suggest detailed observation of resource availability in multiple environments and a knowledgeable economic organization, although technologies were simple and campsites were seemingly ephemeral and discontinuous. These findings raise questions about the pace of early human movement along some areas of the Pacific coast and the level of knowledge and technology required to exploit maritime and inland resources.

  14. Late Pleistocene dune activity in the central Great Plains, USA

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    Mason, J.A.; Swinehart, J.B.; Hanson, P.R.; Loope, D.B.; Goble, R.J.; Miao, X.; Schmeisser, R.L.

    2011-01-01

    Stabilized dunes of the central Great Plains, especially the megabarchans and large barchanoid ridges of the Nebraska Sand Hills, provide dramatic evidence of late Quaternary environmental change. Episodic Holocene dune activity in this region is now well-documented, but Late Pleistocene dune mobility has remained poorly documented, despite early interpretations of the Sand Hills dunes as Pleistocene relicts. New optically stimulated luminescence (OSL) ages from drill cores and outcrops provide evidence of Late Pleistocene dune activity at sites distributed across the central Great Plains. In addition, Late Pleistocene eolian sands deposited at 20-25 ka are interbedded with loess south of the Sand Hills. Several of the large dunes sampled in the Sand Hills clearly contain a substantial core of Late Pleistocene sand; thus, they had developed by the Late Pleistocene and were fully mobile at that time, although substantial sand deposition and extensive longitudinal dune construction occurred during the Holocene. Many of the Late Pleistocene OSL ages fall between 17 and 14 ka, but it is likely that these ages represent only the later part of a longer period of dune construction and migration. At several sites, significant Late Pleistocene or Holocene large-dune migration also probably occurred after the time represented by the Pleistocene OSL ages. Sedimentary structures in Late Pleistocene eolian sand and the forms of large dunes potentially constructed in the Late Pleistocene both indicate sand transport dominated by northerly to westerly winds, consistent with Late Pleistocene loess transport directions. Numerical modeling of the climate of the Last Glacial Maximum has often yielded mean monthly surface winds southwest of the Laurentide Ice Sheet that are consistent with this geologic evidence, despite strengthened anticyclonic circulation over the ice sheet. Mobility of large dunes during the Late Pleistocene on the central Great Plains may have been the result of

  15. Late Pliocene - Early Pleistocene paleoenvironmental reconstruction based on stable isotope compositions of Stephanorhinus sp. and Mammut sp. teeth

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    Szabó, Péter; Kovács, János; Kocsis, László; Gasparik, Mihály; Vennemann, Torsten; Demény, Attila; Virág, Attila

    2014-05-01

    Stable isotope measurements of skeletal apatite from herbivorous mammals are often used to provide information on the terrestrial paleoenvironment and paleoclimate. In this study fossil teeth of Stephanorhinus Kretzoi 1942 (rhinoceros) and Mammut Blumenbach 1799 (mastodon), amongst others, were investigated from the Carpathian Basin. According to the biostratigraphy, the age of the samples has a range from Late Pliocene to Early Pleistocene. Reconstructing paleoclimate and paleoenvironment of this era is important as it can be an analogue for the future climate. Oxygen and carbon isotopic compositions were measured from the tooth enamel, because it is believed to be the most resistant to diagenetic alteration (e.g., Kohn & Cerling, 2002). The carbon isotopic composition in the carbonate fraction of apatite can be related to the diet of the animal (Kohn & Cerling, 2002). Hence, it can reflect the photosynthetic pathway (C3 or C4) of the plants consumed by these herbivores. The δ18O values were determined in the phosphate fraction of apatite. In the case of large mammals that are obligate drinkers, the δ18O values closely track those of the environmental water (Bryant & Froelich, 1995). Knowing the δ18O values of environmental water and relating it to local precipitation, the mean annual temperature (MAT) of the site can be calculated (Dansgaard, 1964). The δ13C values range from -10 to -15 o (VPDB). The result clearly shows that these animals consumed C3 plants. Most of the δ13C values indicate mixed grassland-open woodland rather than a closed canopy forest. Although there is variation in the δ18O values (mean 14.2 ± 1.0 o VSMOW, n=17), most of the samples would support a MAT range of 8-12 ° C. This is in good agreement with other proxies for the localities and time period (Kovács et al., 2013). Bryant, D.J. & Froelich, P.N. (1995) A model of oxygen-isotope fractionation in bodywater of large-mammals. Geochimica et Cosmochimica Acta 59, 4523

  16. A new record of late Pliocene-early Pleistocene aeolian loess-red clay deposits from the western Chinese Loess Plateau and its palaeoenvironmental implications

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    Zan, Jinbo; Fang, Xiaomin; Zhang, Weilin; Yan, Maodu; Zhang, Dawen

    2018-04-01

    The loess-red clay sequences in northern China provide high-resolution terrestrial records of Asian monsoon evolution and aridification of the Asian interior. To date, however, aeolian deposits of late Pliocene-early Pleistocene age (3.5-2.4 Ma) have only rarely been reported from the western Chinese Loess Plateau (CLP), which significantly hinders our understanding of the distribution of aeolian deposits and the palaeoenvironmental evolution of the region. Here, we present magnetostratigraphic, lithologic and magnetic susceptibility results for two recently-drilled boreholes from the north bank of Baxie River, central Linxia Basin, which are highly correlative with those of the loess-red clay deposits spanning the interval from 3.6 to 2.4 Ma in the eastern CLP. Our results provide the first direct evidence for the occurrence of late Pliocene-early Pleistocene aeolian deposits in the western CLP and provide new insights into the distribution of aeolian deposits in northern China. The spatial coherence of the magnetic susceptibility fluctuations further indicates that magnetic susceptibility is a powerful tool for stratigraphic correlation of late Pliocene aeolian deposits in the western CLP. In addition, our results demonstrate that erosional events may have occurred in the early or middle Pleistocene, and they may provide new insights into the reasons for the absence of loess-red clay deposits from 3.5 to 2.4 Ma in most parts of the western CLP.

  17. A reassessment of the early archaeological record at Leang Burung 2, a Late Pleistocene rock-shelter site on the Indonesian island of Sulawesi

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    Hakim, Budianto; Ramli, Muhammad; Aubert, Maxime; van den Bergh, Gerrit D.; Li, Bo; Burhan, Basran; Saiful, Andi Muhammad; Siagian, Linda; Sardi, Ratno; Jusdi, Andi; Abdullah; Mubarak, Andi Pampang; Moore, Mark W.; Roberts, Richard G.; Zhao, Jian-xin; McGahan, David; Jones, Brian G.; Perston, Yinika; Szabó, Katherine; Mahmud, M. Irfan; Westaway, Kira; Jatmiko; Saptomo, E. Wahyu; van der Kaars, Sander; Grün, Rainer; Wood, Rachel; Dodson, John

    2018-01-01

    This paper presents a reassessment of the archaeological record at Leang Burung 2, a key early human occupation site in the Late Pleistocene of Southeast Asia. Excavated originally by Ian Glover in 1975, this limestone rock-shelter in the Maros karsts of Sulawesi, Indonesia, has long held significance in our understanding of early human dispersals into ‘Wallacea’, the vast zone of oceanic islands between continental Asia and Australia. We present new stratigraphic information and dating evidence from Leang Burung 2 collected during the course of our excavations at this site in 2007 and 2011–13. Our findings suggest that the classic Late Pleistocene modern human occupation sequence identified previously at Leang Burung 2, and proposed to span around 31,000 to 19,000 conventional 14C years BP (~35–24 ka cal BP), may actually represent an amalgam of reworked archaeological materials. Sources for cultural materials of mixed ages comprise breccias from the rear wall of the rock-shelter–remnants of older, eroded deposits dated to 35–23 ka cal BP–and cultural remains of early Holocene antiquity. Below the upper levels affected by the mass loss of Late Pleistocene deposits, our deep-trench excavations uncovered evidence for an earlier hominin presence at the site. These findings include fossils of now-extinct proboscideans and other ‘megafauna’ in stratified context, as well as a cobble-based stone artifact technology comparable to that produced by late Middle Pleistocene hominins elsewhere on Sulawesi. PMID:29641524

  18. Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling

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    J. Etourneau

    2012-09-01

    Full Text Available The global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS, off Namibia, where it is known as the Matuyama Diatom Maximum (MDM. Our study focuses on a new diatom silicon isotope (δ30Si record covering the MDM in the BUS. Unexpectedly, the variations in δ30Si signal follow biogenic opal content, whereby the highest δ30Si values correspond to the highest biogenic opal content. We interpret the higher δ30Si values during the MDM as a result of a stronger degree of silicate utilisation in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Late Pliocene/Early Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO2 to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO2 release to the atmosphere, led to further enhanced atmospheric CO2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling.

  19. A New Tephrochronology for Early Diverse Stone Tool Technologies and Long-Distance Raw Material Transport in the Middle-Late Pleistocene Kapthurin Formation, East Africa.

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    Blegen, N.; Jicha, B.

    2017-12-01

    The Middle to Late Pleistocene (780-10 ka) of East Africa records significant behavioral change, the earliest fossils of Homo sapiens and the dispersals of our species across and out of Africa. Studying human evolution in the Middle to Late Pleistocene thus requires an extensive and precise chronology relating the appearances of various behaviors preserved in archaeological sequences to aspects of hominin biology and evidence of past environments preserved in the fossils and geological sequences. Tephrochronology provides the chronostratigraphic resolution to achieve this through correlation and dating of volcanic ashes. The tephrochronology of the Kapthurin Formation presented here, based on tephra correlations and 40Ar/ 39Ar dates, provides new ages between 396.3 ± 3.4 ka and 465.3 ± 1.0 ka for nine sites showing some of the earliest evidence of diverse blade and Levallois methods of core reduction. These are >110 kyr older than previously known in East Africa. New 40Ar/ 39Ar dates provide a refined age of 222.5 ± 0.6 ka for early evidence of long-distance obsidian transport at the Sibilo School Road Site. Long-distance tephra correlation between the Baringo and Lake Victoria basins also provides a new date of 100 ka for the Middle Stone Age site of Keraswanin. By providing new or older dates for 11 sites containing several important aspects of hominin behavior and extending the chronology of the Kapthurin Formation forward by 130,000 years, the tephrochronology presented here contributes one of the longest and most refined chronostratigraphic frameworks relevant to modern human evolution. In conjunction with recent archaeological and paleoenvironmental data, this tephrochronology provides the foundation to understand the process of modern human behavioral evolution through the East African Middle and Late Pleistocene as it relates to biological and paleoenvironmental circumstances.

  20. Dinoflagellate cysts and the paleoenvironment of Late-Pliocene early-pleistocene deposits of Brittany, Northwest France

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    Morzadec-Kerfourn, Marie Thérèse

    The marine Pliocene facies of the Redon clay is widely distributed in the western part of Brittany. the decrease in the abundance of Tertiary pollen towards the top of the deposits, coupled with the increase of pollen of boreal forest taxa and the development of Ericaceae and Poaceae indicates a Late-Pliocene age. The occurrence of the transgression maximum is recorded in calcareous beds which contain the highest concentration of microforaminiferal linings and dinoflagellate cysts. Hystrichokolpoma rigaudae and Melitasphaeridium choanophorum, along with Achomosphaera andalousiensis and Operculodinium israelianum make up these aseemblages. The presence of dinoflagellate cyst assemblages with estuarine and neritic affinities but with an occasional oceanic form, indicates sedimentation in coastal waters with a neritic influence. The paleotopography exerts a control on the altitudinal distribution of the Redon clays in the western part of Brittany to the west of the Rennes Basin. The Pliocene-Pleistocene dinoflagelate cyst assemblages of southern England and northwestern france show a remarkable degree of homogeneity in their composition, chiefly expressed in the apparent contradictory association of A. andalousensis and O. israelianum that suggest sedimentation in an unusual type of environment which arose in the context of climatic change and sea-level variations at that time.

  1. A Late Pleistocene sea level stack

    OpenAIRE

    Spratt Rachel M; Lisiecki Lorraine E

    2016-01-01

    Late Pleistocene sea level has been reconstructed from ocean sediment core data using a wide variety of proxies and models. However, the accuracy of individual reconstructions is limited by measurement error, local variations in salinity and temperature, and assumptions particular to each technique. Here we present a sea level stack (average) which increases the signal-to-noise ratio of individual reconstructions. Specifically, we perform principal componen...

  2. The origin and disappearance of the late Pleistocene-early Holocene short-lived coastal wetlands along the Carmel coast, Israel

    Science.gov (United States)

    Sivan, Dorit; Greenbaum, Noam; Cohen-Seffer, Ronit; Sisma-Ventura, Guy; Almogi-Labin, Ahuva

    The formation of short-lived backswamps along the Carmel coast of Israel coincides with the rapid global sea-level rise during the late Pleistocene-early Holocene transition. The current study shows that the wetland phenomena originated around 10,000 yr ago and dried up shortly before the local Pre-Pottery Neolithic humans settled on the wetland dark clay sediments 9430 cal yr BP. Palaeontological and stable-isotope data were used in this study to elucidate previously published sedimentological reconstruction obtained from a core drilled into the western trough of the Carmel coastal plain. The water body contained typical brackish calcareous fauna, with variable numerical abundance and low species richness of ostracods and foraminifera. The δ 18O and δ 13C of the ostracod Cyprideis torosa show close similarity to the present Pleistocene coastal aquifer isotopic values. This study therefore concludes that the wetlands were shallow-water bodies fed by groundwater, with no evidence of sea-water mixing. It seems that they developed as the result of high groundwater levels, transportation of sediments landward, and deposition of sand bars at the paleo-river mouths. It is still not fully understood why these wetlands deteriorated abruptly and disappeared within less than 1000 yr.

  3. A new tephrochronology for early diverse stone tool technologies and long-distance raw material transport in the Middle to Late Pleistocene Kapthurin Formation, East Africa.

    Science.gov (United States)

    Blegen, Nick; Jicha, Brian R; McBrearty, Sally

    2018-05-09

    The Middle to Late Pleistocene (780-10 ka) of East Africa records evidence of significant behavioral change, early fossils of Homo sapiens, and the dispersals of our species across and out of Africa. Studying human evolution in this time period thus requires an extensive and precise chronology relating behavioral evidence from archaeological sequences to aspects of hominin biology and evidence of past environments from fossils and geological sequences. Tephrochronology provides the chronostratigraphic resolution to achieve this through correlation and dating of volcanic ashes. The tephrochronology of the Kapthurin Formation presented here, based on tephra correlations and 40 Ar/ 39 Ar dates, provides new ages between 395.6 ± 3.5 ka and 465.3 ± 1.0 ka for nine sites showing diverse blade and Levallois methods of core reduction. These are >110 kyr older than previously known in East Africa. New 40 Ar/ 39 Ar dates provide a refined age of 222.5 ± 0.6 ka for early evidence of long-distance (166 km) obsidian transport at the Sibilo School Road Site. A tephra correlation between the Baringo and Victoria basins also provides a new date of ∼100 ka for the Middle Stone Age site of Keraswanin. By providing new and older dates for 11 sites containing several important aspects of hominin behavior and extending the chronology of the Kapthurin Formation forward by ∼130,000 years, the tephrochronology presented here contributes one of the longest and most refined chronostratigraphic frameworks of Middle through Late Pleistocene East Africa. This tephrochronology thus provides the foundation to understand the process of modern human behavioral evolution as it relates to biological and paleoenvironmental circumstances. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Fossils in Late Cretaceous to early Palaeocene flint nodules embedded in pleistocene glaciofluvial sediments near Fukov (Děčín District, Northern Bohemia)

    Czech Academy of Sciences Publication Activity Database

    Pokorný, R.; Kaše, J.; Kvaček, J.; Zágoršek, K.; Kočí, T.; Žítt, Jiří

    2012-01-01

    Roč. 68, 3/4 (2012), s. 119-131 ISSN 0036-5343 Institutional support: RVO:67985831 Keywords : Erratic boulders * Flint * Glaciofluvial sediments * Late Cretaceous * Northern Bohemia * Palaeocene * Pleistocene glaciation * Taphocoenosis Subject RIV: DB - Geology ; Mineralogy http://www.nm.cz/publikace/archiv.php?id=4&rok=68&kcislu=3-4&f_=Zobrazit

  5. Limestone percussion tools from the late Early Pleistocene sites of Barranco León and Fuente Nueva 3 (Orce, Spain).

    Science.gov (United States)

    Barsky, Deborah; Vergès, Josep-María; Sala, Robert; Menéndez, Leticia; Toro-Moyano, Isidro

    2015-11-19

    In recent years, there is growing interest in the study of percussion scars and breakage patterns on hammerstones, cores and tools from Oldowan African and Eurasian lithic assemblages. Oldowan stone toolkits generally contain abundant small-sized flakes and their corresponding cores, and are characterized by their structural dichotomy of heavy- and light-duty tools. This paper explores the significance of the lesser known heavy-duty tool component, providing data from the late Lower Pleistocene sites of Barranco León and Fuente Nueva 3 (Orce, Spain), dated 1.4-1.2 Myr. Using quantitative and qualitative data from the large-sized limestone industries from these two major sites, we present a new methodology highlighting their morpho-technological features. In the light of the results, we discuss the shortfalls of extant classificatory methods for interpreting the role of percussive technology in early toolkits. This work is rooted in an experimental program designed to reproduce the wide range of percussion marks observed on the limestone artefacts from these two sites. A visual and descriptive reference is provided as an interpretative aid for future comparative research. Further experiments using a variety of materials and gestures are still needed before the elusive traces yield the secrets of the kinds of percussive activities carried out by hominins at these, and other, Oldowan sites. © 2015 The Author(s).

  6. Millennial-scale climate variations in western Mediterranean during late Pleistocene-early Holocene: multi-proxy analyses from Padul peatbog (southern Iberian Peninsula)

    Science.gov (United States)

    Camuera, Jon; Jiménez-Moreno, Gonzalo; José Ramos-Román, María; García-Alix, Antonio; Jiménez-Espejo, Francisco; Toney, Jaime L.; Anderson, R. Scott; Kaufman, Darrell; Bright, Jordon; Sachse, Dirk

    2017-04-01

    Padul peatbog, located in southern Iberian Peninsula (western Mediterranean region) is a unique area for palaeoenvironmental studies due to its location, between arid and temperate climates. Previous studies showed that the Padul peatbog contains a continuous record of the last ca. 0.8-1 Ma, so it is an extraordinary site to identify glacial-interglacial phases as well as Heinrich and D-O events, linked to orbital- and suborbital-scale variations. In 2015, a new 42 m long core was taken from this area, providing an excellent sediment record probably for the last ca. 300,000 years. This study is focused on the paleoenvironmental and climatic reconstruction of the late Pleistocene and the early Holocene (ca. from 50,000 to 9,500 cal. yrs BP), using AMS 14C and AAR dating, high-resolution pollen analysis, lithology, continuous XRF-scanning, X-ray diffraction, magnetic susceptibility and organic geochemistry. These different proxies provide information not only about the regional environment change but also about local changes in the conditions of the Padul lake/peatbog due to variations in water temperature, pH or nutrients.

  7. Equatorial Pacific peak in biological production regulated by nutrient and upwelling during the late Pliocene/early Pleistocene cooling

    Directory of Open Access Journals (Sweden)

    J. Etourneau

    2013-08-01

    Full Text Available The largest increase in export production in the eastern Pacific of the last 5.3 Myr (million years occurred between 2.2 and 1.6 Myr, a time of major climatic and oceanographic reorganization in the region. Here, we investigate the causes of this event using reconstructions of export production, nutrient supply and oceanic conditions across the Pliocene–Pleistocene in the eastern equatorial Pacific (EEP for the last 3.2 Myr. Our results indicate that the export production peak corresponds to a cold interval marked by high nutrient supply relative to consumption, as revealed by the low bulk sedimentary 15N/14N (δ15N and alkenone-derived sea surface temperature (SST values. This ∼0.6 million year long episode of enhanced delivery of nutrients to the surface of the EEP was predominantly initiated through the upwelling of nutrient-enriched water sourced in high latitudes. In addition, this phenomenon was likely promoted by the regional intensification of upwelling in response to the development of intense Walker and Hadley atmospheric circulations. Increased nutrient consumption in the polar oceans and enhanced denitrification in the equatorial regions restrained nutrient supply and availability and terminated the high export production event.

  8. Possible linkage between supernovae, increased terrestrial lightning, and wildfire activity in the Late Miocene and Early Pleistocene

    Science.gov (United States)

    Thomas, B. C.; Feulner, G.; Melott, A. L.; Kirsten, T.; von Bloh, W.

    2017-12-01

    Radioisotopes from deep-sea deposits show that Earth was affected by nearby supernovae about 2.5 and 8 million years ago. Recent modelling work shows that high-energy particles from these events resulted in greatly enhanced ionization of the troposphere. This could have led to an increase in wildfires via more frequent lightning. Here we show that published data on global fire activity from charcoal records reveal a marked increase in wildfires around the times of the supernova explosions. We use a dynamic global vegetation model to assess the impact of increased lightning frequency on vegetation patterns, finding a patchy global decrease in tree cover. Regionally, vegetation changes are particularly pronounced in western North America, the Mediterranean, Central Asia, Northern Indochina, subtropical South America, Africa and Australia, and notably East Africa, in agreement with empirical evidence for a global shift towards savannas during the Pleistocene. Our results demonstrate that moderately nearby supernovae have the potential to affect life on Earth even if they are too distant to initiate a mass extinction. Finally, we note that the shift from forest to savannah biomes in the East African Rift Valley region has been tentatively linked to hominin evolution in this region.

  9. CANIS LUPUS (MAMMALIA, CANIDAE FROM THE LATE PLEISTOCENE DEPOSIT OF AVETRANA (TARANTO, SOUTHERN ITALY

    Directory of Open Access Journals (Sweden)

    DAVIDE F.BERTÈ

    2014-11-01

    Full Text Available Here we described the remains of Canis lupus from the bed 8 of Avetrana karst filling (Late Pleistocene; Taranto, Southern Italy. The studied specimens are larger than those collected from the early Late Pleistocene Apulian localities and those referred to the recent Italian wolf. Moreover, the remains from Avetrana are morphometrically close to Canis lupus maximus from France and to C. lupus collected from Central and Northern Italian localities, chronologically related to MIS 2 and MIS 3. Morphologically, the studied specimens slightly differ from both C. l. maximus and other Pleistocene Apulian wolves. The dimensional differences between the Avetrana wolves and those collected from the other early Late Pleistocene Apulian localities could be explained through a spread of a large-sized morphotype from the Northern Italy.

  10. Transitional changes in microfossil assemblages in the Japan Sea from the Late Pliocene to Early Pleistocene related to global climatic and local tectonic events

    Science.gov (United States)

    Itaki, Takuya

    2016-12-01

    Many micropaleontological studies based on data from on-land sections, oil wells, and deep-sea drilling cores have provided important information about environmental changes in the Japan Sea that are related to the global climate and the local tectonics of the Japanese Islands. Here, major changes in the microfossil assemblages during the Late Pliocene to Early Pleistocene are reviewed. Late Pliocene (3.5-2.7 Ma) surface-water assemblages were characterized mainly by cold-temperate planktonic flora and fauna (nannofossils, diatoms, radiolarians, and planktonic foraminifera), suggesting that nutrient-rich North Pacific surface waters entered the Japan Sea via northern straits. The common occurrence of Pacific-type deep-water radiolarians during this period also suggests that deep water from the North Pacific entered the Japan Sea via the northern straits, indicating a sill depth >500 m. A weak warm-water influence is recognized along the Japanese coast, suggesting a small inflow of warm water via a southern strait. Nannofossil and sublittoral ostracod assemblages record an abrupt cooling event at 2.75 Ma that correlates with the onset of the Northern Hemisphere glaciation. Subsequently, cold intermediate- and deep-water assemblages of ostracods and radiolarians increased in abundance, suggesting active ventilation and the formation of the Japan Sea Proper Water, associated with a strengthened winter monsoon. Pacific-type deep-water radiolarians also disappeared around 2.75 Ma, which is attributed to the intermittent occurrence of deep anoxic environments and limited migration from the North Pacific, resulting from the near-closure or shallowing of the northern strait by a eustatic fall in sea level and tectonic uplift of northeastern Japan. A notable reduction in primary productivity from 2.3 to 1.3 Ma also suggests that the nutrient supply from the North Pacific was restricted by the near-closure of the northern strait. An increase in the abundance of subtropical

  11. Late Pleistocene and Holocene mammal extinctions on continental Africa

    Science.gov (United States)

    Faith, J. Tyler

    2014-01-01

    Understanding the cause of late Quaternary mammal extinctions is the subject of intense debate spanning the fields of archeology and paleontology. In the global context, the losses on continental Africa have received little attention and are poorly understood. This study aims to inspire new discussion of African extinctions through a review of the extinct species and the chronology and possible causes of those extinctions. There are at least 24 large mammal (> 5 kg) species known to have disappeared from continental Africa during the late Pleistocene or Holocene, indicating a much greater taxonomic breadth than previously recognized. Among the better sampled taxa, these losses are restricted to the terminal Pleistocene and early Holocene, between 13,000 and 6000 yrs ago. The African extinctions preferentially affected species that are grazers or prefer grasslands. Where good terrestrial paleoenvironmental records are present, extinctions are associated with changes in the availability, productivity, or structure of grassland habitats, suggesting that environmental changes played a decisive role in the losses. In the broader evolutionary context, these extinctions represent recent examples of selective taxonomic winnowing characterized by the loss of grassland specialists and the establishment of large mammal communities composed of more ecologically flexible taxa over the last million years. There is little reason to believe that humans played an important role in African extinctions.

  12. Size variation in early human mandibles and molars from Klasies River, South Africa: comparison with other middle and late Pleistocene assemblages and with modern humans.

    Science.gov (United States)

    Royer, Danielle F; Lockwood, Charles A; Scott, Jeremiah E; Grine, Frederick E

    2009-10-01

    Previous studies of the Middle Stone Age human remains from Klasies River have concluded that they exhibited more sexual dimorphism than extant populations, but these claims have not been assessed statistically. We evaluate these claims by comparing size variation in the best-represented elements at the site, namely the mandibular corpora and M(2)s, to that in samples from three recent human populations using resampling methods. We also examine size variation in these same elements from seven additional middle and late Pleistocene sites: Skhūl, Dolní Vestonice, Sima de los Huesos, Arago, Krapina, Shanidar, and Vindija. Our results demonstrate that size variation in the Klasies assemblage was greater than in recent humans, consistent with arguments that the Klasies people were more dimorphic than living humans. Variation in the Skhūl, Dolní Vestonice, and Sima de los Huesos mandibular samples is also higher than in the recent human samples, indicating that the Klasies sample was not unusual among middle and late Pleistocene hominins. In contrast, the Neandertal samples (Krapina, Shanidar, and Vindija) do not evince relatively high mandibular and molar variation, which may indicate that the level of dimorphism in Neandertals was similar to that observed in extant humans. These results suggest that the reduced levels of dimorphism in Neandertals and living humans may have developed independently, though larger fossil samples are needed to test this hypothesis.

  13. Transient nature of late Pleistocene climate variability.

    Science.gov (United States)

    Crowley, Thomas J; Hyde, William T

    2008-11-13

    Climate in the early Pleistocene varied with a period of 41 kyr and was related to variations in Earth's obliquity. About 900 kyr ago, variability increased and oscillated primarily at a period of approximately 100 kyr, suggesting that the link was then with the eccentricity of Earth's orbit. This transition has often been attributed to a nonlinear response to small changes in external boundary conditions. Here we propose that increasing variablility within the past million years may indicate that the climate system was approaching a second climate bifurcation point, after which it would transition again to a new stable state characterized by permanent mid-latitude Northern Hemisphere glaciation. From this perspective the past million years can be viewed as a transient interval in the evolution of Earth's climate. We support our hypothesis using a coupled energy-balance/ice-sheet model, which furthermore predicts that the future transition would involve a large expansion of the Eurasian ice sheet. The process responsible for the abrupt change seems to be the albedo discontinuity at the snow-ice edge. The best-fit model run, which explains almost 60% of the variance in global ice volume during the past 400 kyr, predicts a rapid transition in the geologically near future to the proposed glacial state. Should it be attained, this state would be more 'symmetric' than the present climate, with comparable areas of ice/sea-ice cover in each hemisphere, and would represent the culmination of 50 million years of evolution from bipolar nonglacial climates to bipolar glacial climates.

  14. Determining Late Pleistocene to Early Holocene deglaciation of the Baltic Ice Lake through sedimentological core sample analysis of IODP Site M0064

    Science.gov (United States)

    Kelly, A. L.; Passchier, S.

    2016-12-01

    This study investigates the deglaciation history of the Scandinavian Ice Sheet (SIS) within the Baltic Sea's Hanö Bay from the Late Pleistocene to the Holocene using samples from International Ocean Discovery Program (IODP) Site M0064. The research aims to understand how the speed of deglaciation influences Baltic Ice Lake (BIL) drainage patterns and relative sea level changes on a high-resolution timescale. Glacial history of the SIS has been studied through glacial till analysis, surface exposure dating, and modeling, encompassing its most recent deglaciation 20-14ka BP, and suggests ice retreated from the project site 16.7ka BP. Between 17 and 14ka BP global sea level rose 4 meters per century, accompanied by a dramatic increase in atmospheric carbon. This period of rapid sea level rise and global warming is a valuable analog for understanding the Earth's current and projected climate. This project uses particle size analysis to better understand the late-glacial depositional environment in Hanö Bay, and ICP-OES geochemical analysis for evidence pertaining to changing sediment provenance and bottom water oxygenation in the BIL. Diamicton is present between 47 and 9 mbsf in Hole M0064D. At 8 mbsf, the sediment exhibits a prominent upward transition from well-laminated cm-scale grey to more thinly laminated reddish brown rhythmites. With calculated Al/Ti ratios, we find that there is not much provenance change in the sequence, however we see fluctuations in Mn/Al ratios, implying shifts in sediment color may be chemical, possibly indicating redox changes in the water column during sediment deposition. Although we find that particle size in the varve sequence does not change, this factor may be driving chemical fluctuations in the diamicton. These results increase the understanding of ice retreat, paleocirculation and relative sea level changes in the Baltic Sea at the onset of the last deglaciation.

  15. Early pleistocene sediments at Great Blakenham, Suffolk, England

    Science.gov (United States)

    Gibbard, P. L.; Allen, P.; Field, M. H.; Hallam, D. F.

    Detailed investigation of a fine sediment sequence, the College Farm Silty Clay Member, that overlies the Creeting Sands (Early Pleistocene) in Suffolk, is presented. The sedimentary sequence is thought to represent a freshwater pool accumulation in a small coastal embayment. Palaeobotanical investigation of the sediment indicates that it accumulated during the late temperate substage of a temperate (interglacial) event. The occurrence of Tsuga pollen, associated with abundant remains of the water fern Azolla tegeliensis indicate that the deposits are of Early Pleistocene age and are correlated with a later part of the Antian-Bramertonian Stage. Correlation with Tiglian TO substage in The Netherlands' sequence is most likely. The sediments' normal palaeomagnetic polarity reinforces the biostratigraphical correlation.

  16. Canyon Creek: A late Pleistocene vertebrate locality in interior Alaska

    Science.gov (United States)

    Weber, Florence R.; Hamilton, Thomas D.; Hopkins, David M.; Repenning, Charles A.; Haas, Herbert

    1981-09-01

    The Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000-17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf. O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode.

  17. Late Middle Pleistocene hominin teeth from Panxian Dadong, South China.

    Science.gov (United States)

    Liu, Wu; Schepartz, Lynne A; Xing, Song; Miller-Antonio, Sari; Wu, Xiujie; Trinkaus, Erik; Martinón-Torres, María

    2013-05-01

    The hominin teeth and evidence of hominin activities recovered from 1991 to 2005 at the Panxian Dadong site in South China are dated to the late Middle Pleistocene (MIS 8-6 or ca. 130-300 ka), a period for which very little is known about the morphology of Asian populations. The present study provides the first detailed morphometric description and comparisons of four hominin teeth (I(1), C1, P(3) and P3) from this site. Our study shows that the Panxian Dadong teeth combine archaic and derived features that align them with Middle and Upper Pleistocene fossils from East and West Asia and Europe. These teeth do not display any typical Neanderthal features and they are generally more derived than other contemporaneous populations from Asia and Africa. However, the derived traits are not diagnostic enough to specifically link the Panxian Dadong teeth to Homo sapiens, a common problem when analyzing the Middle Pleistocene dental record from Africa and Asia. These findings are contextualized in the discussion of the evolutionary course of Asian Middle Pleistocene hominins, and they highlight the necessity of incorporating the Asian fossil record in the still open debate about the origin of H. sapiens. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Origin of late pleistocene formation water in Mexican oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Birkle, P. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    2004-07-01

    . For wellhead samples, a 20 liter-sampling-reagent was previously filled with N{sub 2}-gas for the collection and phase separation of the pressurized gas-water-crude oil mixture. No differences in {sup 14}C-concentrations were detected applying, both, conventional and AMS-techniques. In contradiction to the expected 'fossil age' of reservoir water as part of a stagnant hydraulic system, measured {sup 14}C-concentrations between 0.89 pmC and 31.86 pmC indicate a late Pleistocene-early Holocene, regional event for the infiltration of surface water into the reservoir. The variety in water mineralization from meteoric (TDS{sub max} = 0.5 g/l) to hyper-saline composition (TDS{sub max} = 338 g/l) is not caused by halite dissolution from adjacent salt domes, as shown by elevated Br/Cl ratios. In contrary, the linear correlation between {sup 18}O and Cl values reflect varying mixing proportions of two components - meteoric water and evaporated seawater. Instead of water/rock-interaction, evaporation of seawater at the surface prior to infiltration represents the principal process for fluid enrichment in {sup 18}O and chlorine, with maximum values of 17.2 %o and 228 g/l, respectively. The young residence time of formation water in Mexican oil reservoirs implies following: - The common assumption of 'hydraulically-frozen' reservoirs is not correct, as main descending fluid migration occurred during glacial period. Probably, major infiltration processes are related to periods with climatic changes and increased humidity - as observed for the adjacent Yucatan region in SE-Mexico during early-mid Holocene (6,000 yr BP) (Metcalfe et al. 2000) - with the probable transgression of Mexican Gulf seawater into the recent Mexican coastal plain. - The common hypothesis of hydrocarbon maturation within Jurassic organic-rich layers, and its subsequent expulsion and migration into Cretaceous/Tertiary sedimentary units must be expanded by a last-step-process: As glacial

  19. Snapshots of the Greenland ice sheet configuration in the Pliocene to early Pleistocene

    DEFF Research Database (Denmark)

    Solgaard, Anne M.; Reeh, Niels; Japsen, Peter

    2011-01-01

    The geometry of the ice sheets during the Pliocene to early Pleistocene is not well constrained. Here we apply an ice-flow model in the study of the Greenland ice sheet (GIS) during three extreme intervals of this period constrained by geological observations and climate reconstructions. We study...... the extent of the GIS during the Mid-Pliocene Warmth (3.3-3.0 Ma), its advance across the continental shelf during the late Pliocene to early Pleistocene glaciations (3.0-2.4 Ma) as implied by offshore geological studies, and the transition from glacial to interglacial conditions around 2.4 Ma as deduced...... the variability of the GIS during the Pliocene to early Pleistocene and underline the importance of including independent estimates of the GIS in studies of climate during this period. We conclude that the GIS did not exist throughout the Pliocene to early Pleistocene, and that it melted during interglacials even...

  20. The late Middle Pleistocene hominin fossil record of eastern Asia: synthesis and review.

    Science.gov (United States)

    Bae, Christopher J

    2010-01-01

    Traditionally, Middle Pleistocene hominin fossils that cannot be allocated to Homo erectus sensu lato or modern H. sapiens have been assigned to different specific taxa. For example, in eastern Asia, these hominin fossils have been classified as archaic, early, or premodern H. sapiens. An increasing number of Middle Pleistocene hominin fossils are currently being assigned to H. heidelbergensis. This is particularly the case for the African and European Middle Pleistocene hominin fossil record. There have been suggestions that perhaps the eastern Asian late Middle Pleistocene hominins can also be allocated to the H. heidelbergensis hypodigm. In this article, I review the current state of the late Middle Pleistocene hominin fossil record from eastern Asia and examine the various arguments for assigning these hominins to the different specific taxa. The two primary conclusions drawn from this review are as follows: 1) little evidence currently exists in the eastern Asian Middle Pleistocene hominin fossil record to support their assignment to H. heidelbergensis; and 2) rather than add to the growing list of hominin fossil taxa by using taxonomic names like H. daliensis for northeast Asian fossils and H. mabaensis for Southeast Asian fossils, it is better to err on the side of caution and continue to use the term archaic H. sapiens to represent all of these hominin fossils. What should be evident from this review is the need for an increase in the quality and quantity of the eastern Asian hominin fossil data set. Fortunately, with the increasing number of large-scale multidisciplinary paleoanthropological field and laboratory research projects in eastern Asia, the record is quickly becoming better understood. Copyright © 2010 Wiley-Liss, Inc.

  1. A NEW EARLY PLEISTOCENE BIRD ASSOCIATION FROM PIETRAFITTA (PERUGIA, CENTRAL ITALY

    Directory of Open Access Journals (Sweden)

    GILDA ZUCCHETTA

    2003-11-01

    Full Text Available We here present che preliminary results of the analysis of the fossil bird assemblages found in the lignite deposits of the Pietrafitta Mine (Perugia, Central Italy. A rich vertebrate association, mainly mammals, has been retrieved in Pietrafitta, which is the richest local fauna of the Farneta Faunal Unit (late Villafranchian, early Pleistocene. Avian remains of Podicipedidae, Ardeidae, Phalacrocoracidae, Anatidae, Phasianidae and Rallidae have been identified, for most of which Pietrafitta represents the earliest occurrence in Italy. The Pietrafitta fossil bird association is the first Italian bird assemblage of the Early Pleistocene and seems to be one of the most important ones for the early Pleistocene in Europe, especially because it contains mainly aquatic birds, often rare in many other European deposits. 

  2. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA

    OpenAIRE

    Stephen J. Jacquemin; Jun A. Ebersole; William C. Dickinson; Charles N. Ciampaglio

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (?10,000 to 30,000 years B.P.) lead...

  3. Global Implications of late Pleistocene Megafaunal Extinctions in the Holarctic

    Science.gov (United States)

    Cooper, Alan; Turney, Chris

    2017-04-01

    Improved resolution data from radiocarbon, climate and ancient DNA studies of megafauna and humans is providing the first ability to disentangle the roles of climate change and human impact in the Late Pleistocene megafaunal extinctions. In the Holarctic we find that megafaunal populations underwent repeated local or global extinctions apparently associated with abrupt, centennial to millennial duration warming events (Dansgaard-Oeschger interstadials). Importantly, the extinction events took place both before and after the arrival of modern humans in the landscape. Here we look at the possible role of human activity in Holarctic and suggest it may be through the disruption of metapopulation processes which stabilize ecosystems and may have evolved to provide resilience to rapid and frequent climate shifts in the past. The observed relationship between climate and humans on megafaunal populations may provide a model for global extinction. Fortunately in this regard, the rapid movement of the first Native Americans throughout both American continents during the Last Deglaciation provides a powerful and unique model system for testing the competing roles on extinction because the opposing climate trends in each hemisphere at the time. Here we show that while megafaunal extinctions were associated with warming trends in both cases, the out-of-phase climate patterns caused the sequence and timing of events to be mirrored, providing a unique high-resolution view of the interactions of human colonization and rapid climate change on megafaunal ecosystems, with implications for future warming scenarios. References: Cooper, A., Turney, C., Hughen, K.A., Brook, B.W., McDonald, H.G., Bradshaw, C.J.A., 2015. Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover. Science 349, 602-606. Metcalf, J.L., Turney, C., Barnett, R., Martin, F., Bray, S.C., Vilstrup, J.T., Orlando, L., Salas-Gismondi, R., Loponte, D., Medina, M., De Nigris, M., Civalero, T., Fern

  4. Ancient DNA reveals that bowhead whale lineages survived Late Pleistocene climate change and habitat shifts

    DEFF Research Database (Denmark)

    Foote, Andrew David; Kaschner, Kristin; Schultze, Sebastian E.

    2013-01-01

    that a true Arctic species, the bowhead whale (Balaena mysticetus), shifted its range and tracked its core suitable habitat northwards during the rapid climate change of the Pleistocene-Holocene transition. Late Pleistocene lineages survived into the Holocene and effective female population size increased...

  5. Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation

    International Nuclear Information System (INIS)

    Stübner, Konstanze; Grin, Elena; Hidy, Alan J.; Schaller, Mirjam; Gold, Ryan D.

    2017-01-01

    Glacial chronologies provide insight into the evolution of paleo-landscapes, paleoclimate, topography, and the erosion processes that shape mountain ranges. In the Pamir of Central Asia, glacial morphologies and deposits indicate extensive past glaciations, whose timing and extent remain poorly constrained. Geomorphic data and 15 new "1"0Be exposure ages from moraine boulders and roches moutonnées in the southwestern Pamir document multiple Pleistocene glacial stages. The oldest exposure ages, View the MathML source113 ± 10ka, underestimate the age of the earliest preserved glacial advance and imply that the modern relief of the southwestern Pamir (peaks at ~5000–6000 m a.s.l.; valleys at ~2000–3000 m a.s.l.) already existed in the late Middle Pleistocene. Younger exposure ages (~40–80 ka, ~30 ka) complement the existing Central Asian glacial chronology and reflect successively less extensive Late Pleistocene glaciations. The topography of the Pamir and the glacial chronologies suggest that, in the Middle Pleistocene, an ice cap or ice field occupied the eastern Pamir high-altitude plateau, whereas westward flowing valley glaciers incised the southwestern Pamir. Since the Late Pleistocene deglaciation, the rivers of the southwestern Pamir adjusted to the glacially shaped landscape. As a result, localized rapid fluvial incision and drainage network reorganization reflect the transient nature of the deglaciated landscape.

  6. Late Pleistocene glacial fluctuations in Cordillera Oriental, subtropical Andes

    Science.gov (United States)

    Martini, Mateo A.; Kaplan, Michael R.; Strelin, Jorge A.; Astini, Ricardo A.; Schaefer, Joerg M.; Caffee, Marc W.; Schwartz, Roseanne

    2017-09-01

    The behavior of subtropical glaciers during Middle to Late Pleistocene global glacial maxima and abrupt climate change events, specifically in Earth's most arid low-latitude regions, remains an outstanding problem in paleoclimatology. The present-day climate of Cordillera Oriental, in arid northwestern Argentina, is influenced by shifts in subtropical climate systems, including the South American Summer Monsoon. To understand better past glacier-subtropical climates during the global Last Glacial Maximum (LGM, 26.5-19 ka) and other time periods, we combined geomorphic features with forty-two precise 10Be ages on moraine boulders and reconstructed paleo-equilibrium line altitudes (ELA) at Nevado de Chañi (24°S) in the arid subtropical Andes. We found a major glacial expansion at ∼23 ± 1.6 ka, that is, during the global LGM. Additional glacial expansions are observed before the global LGM (at ∼52-39 ka), and after, at 15 ± 0.5 and 12 ± 0.6 ka. The ∼15 ka glacial event was found on both sides of Chañi and the ∼12 ka event is only recorded on the east side. Reconstructed ELAs of the former glaciers exhibit a rise from east to west that resembles the present subtropical climate trajectory from the Atlantic side of the continent; hence, we infer that this climate pattern must have been present in the past. Based on comparison with other low-latitude paleoclimate records, such as those from lakes and caves, we infer that both temperature and precipitation influenced past glacial occurrence in this sector of the arid Andes. Our findings also imply that abrupt deglacial climate events associated with the North Atlantic, specifically curtailed meridional overturning circulation and regional cooling, may have had attendant impacts on low subtropical Southern Hemisphere latitudes, including the climate systems that affect glacial activity around Nevado de Chañi.

  7. Early and late motherhood

    DEFF Research Database (Denmark)

    Christoffersen, Mogens; Lausten, Mette

    2009-01-01

    The study investigates parental child rearing methods, structural factors relating to the family during adolescence geographic segregation, individual resource deficits and social background of first time late live births among 32 to 37 years old women and compare to teenagers before becoming...... economic and social gradient for first-time teenage mothers. Teenagers who had experienced family separation or who were formerly in out-of-home care in particular had an increased risk of early childbearing. Results showed that teenage mothers were in every respect in a more disadvantaged position than...

  8. Expansion of the known distribution of Asiatic mouflon (Ovis orientalis) in the Late Pleistocene of the Southern Levant

    Science.gov (United States)

    Yeomans, Lisa; Martin, Louise; Richter, Tobias

    2017-08-01

    Wild sheep (Ovis orientalis) bones recovered from the Natufian site of Shubayqa 1 demonstrate a wider distribution of mouflon in the Late Pleistocene of the Southern Levant than previously known. Early Epipalaeolithic sites are common in the limestone steppe region of eastern Jordan but have yielded only a handful of caprine bones that cannot be identified to species level and few faunal remains from excavated Late Epipalaeolithic sites have been reported. Analysis of animal bone from Shubayqa 1 suggests a significant population of wild sheep could be found concentrated in the basalt desert environment of eastern Jordan during the Late Pleistocene, especially where higher rainfall over the Jebel Druze provided more water. A population of wild sheep was still present in the Pre-Pottery Neolithic A when the nearby site of Shubayqa 6 was occupied. Hunting of diverse, locally available resources including wild sheep at the end of the Pleistocene illustrates the flexible and adaptive exploitation strategies that hunter-forager groups engaged in. This provides further evidence to the increasing body of data showing the creative and opportunistic approach of terminal Pleistocene groups allowing continued occupation even in more marginal environments in a period of environmental change.

  9. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA.

    Science.gov (United States)

    Jacquemin, Stephen J; Ebersole, Jun A; Dickinson, William C; Ciampaglio, Charles N

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  10. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2 in Colbert County, Alabama, USA

    Directory of Open Access Journals (Sweden)

    Stephen J. Jacquemin

    2016-02-01

    Full Text Available The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P. leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL. Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus and a single extinct (Harelip Sucker Moxostoma lacerum taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  11. BIOCHRONOLOGY OF SELECTED MAMMALS, MOLLUSCS AND OSTRACODS FROM THE MIDDLE PLIOCENE TO THE LATE PLEISTOCENE IN ITALY. THE STATE OF THE ART

    Directory of Open Access Journals (Sweden)

    E. GLIOZZI

    1997-11-01

    Full Text Available The Authors have elaborated four range charts of mammalian (large and micro, molluscs and fresh-water and brackish ostracodes faunas, for the selected Plio-Pleistocene fossiliferous localities of the Italy. A new Mammal Age (Aurelian correlatable to late Middle and Late Pleistocene has been defined. Inside this age two Faunal Units (Torre in Pietra and Vitinia have been defined as characteristic for Early and Middle Aurelian, while no gisements have been chosen for the late Aurelian. Biochronological units are calibrated on magnetostratigraphic and isotopic scales and by radiometric datings.    

  12. Lineage-specific late pleistocene expansion of an endemic subtropical gossamer-wing damselfly, Euphaea formosa, in Taiwan

    Directory of Open Access Journals (Sweden)

    Huang Jen-Pan

    2011-04-01

    Full Text Available Abstract Background Pleistocene glacial oscillations have significantly affected the historical population dynamics of temperate taxa. However, the general effects of recent climatic changes on the evolutionary history and genetic structure of extant subtropical species remain poorly understood. In the present study, phylogeographic and historical demographic analyses based on mitochondrial and nuclear DNA sequences were used. The aim was to investigate whether Pleistocene climatic cycles, paleo-drainages or mountain vicariance of Taiwan shaped the evolutionary diversification of a subtropical gossamer-wing damselfly, Euphaea formosa. Results E. formosa populations originated in the middle Pleistocene period (0.3 Mya and consisted of two evolutionarily independent lineages. It is likely that they derived from the Pleistocene paleo-drainages of northern and southern Minjiang, or alternatively by divergence within Taiwan. The ancestral North-central lineage colonized northwestern Taiwan first and maintained a slowly growing population throughout much of the early to middle Pleistocene period. The ancestral widespread lineage reached central-southern Taiwan and experienced a spatial and demographic expansion into eastern Taiwan. This expansion began approximately 30,000 years ago in the Holocene interglacial period. The ancestral southern expansion into eastern Taiwan indicates that the central mountain range (CMR formed a barrier to east-west expansion. However, E. formosa populations in the three major biogeographic regions (East, South, and North-Central exhibit no significant genetic partitions, suggesting that river drainages and mountains did not form strong geographical barriers against gene flow among extant populations. Conclusions The present study implies that the antiquity of E. formosa's colonization is associated with its high dispersal ability and larval tolerance to the late Pleistocene dry grasslands. The effect of late Pleistocene

  13. Using obsidian transfer distances to explore social network maintenance in late Pleistocene hunter-gatherers.

    Science.gov (United States)

    Pearce, Eiluned; Moutsiou, Theodora

    2014-12-01

    Social behaviour is notoriously difficult to study archaeologically and it is unclear how large the networks of prehistoric humans were, or how they remained connected. Maintaining social cohesion was crucial for early humans because social networks facilitate cooperation and are imperative for survival and reproduction. Recent hunter-gatherer social organisation typically comprises a number of nested layers, ranging from the nuclear family through to the ~1500-strong ethnolinguistic tribe. Here we compare maximum obsidian transfer distances from the late Pleistocene with ethnographic data on the size of the geographic areas associated with each of these social grouping layers in recent hunter-gatherers. The closest match between the two is taken to indicate the maximum social layer within which contact could be sustained by Pleistocene hominins. Within both the (sub)tropical African and Subarctic biomes, the maximum obsidian transfer distances for Pleistocene modern humans (~200km and ~400km respectively) correspond to the geographic ranges of the outermost tribal layer in recent hunter-gatherers. This suggests that modern humans could potentially sustain the cohesion of their entire tribe at all latitudes, even though networks are more dispersed nearer the poles. Neanderthal obsidian transfer distances (300km) indicate that although Neanderthal home ranges are larger than those of low latitude hominins, Neanderthals travelled shorter distances than modern humans living at the same high latitudes. We argue that, like modern humans, Neanderthals could have maintained tribal cohesion, but that their tribes were substantially smaller than those of contemporary modern humans living in similar environments. The greater time taken to traverse the larger modern human tribal ranges may have limited the frequency of their face-to-face interactions and thus necessitated additional mechanisms to ensure network connectivity, such as the exchange of symbolic artefacts

  14. Oleistocene mammals in the late-early Holocene in Santa Lucia river basin (Uruguay southern)

    International Nuclear Information System (INIS)

    Ubilla, M.; Perea, D.; Corona, A.; Rinderknecht, A.; Sanchez, A.

    2012-01-01

    This work is about the fossileferous outcrops belongs to the late Pleistocene - early Holocene in Santa Lucia River. It enable to analyse the last records of megafauna vertebrate extinctions (olistecene mammals) with the climate conditions / environment

  15. MicroEcos: Micro-Scale Explorations of Large-Scale Late Pleistocene Ecosystems

    Science.gov (United States)

    Gellis, B. S.

    2017-12-01

    Pollen data can inform the reconstruction of early-floral environments by providing data for artistic representations of what early-terrestrial ecosystems looked like, and how existing terrestrial landscapes have evolved. For example, what did the Bighorn Basin look like when large ice sheets covered modern Canada, the Yellowstone Plateau had an ice cap, and the Bighorn Mountains were mantled with alpine glaciers? MicroEcos is an immersive, multimedia project that aims to strengthen human-nature connections through the understanding and appreciation of biological ecosystems. Collected pollen data elucidates flora that are visible in the fossil record - associated with the Late-Pleistocene - and have been illustrated and described in botanical literature. It aims to make scientific data accessible and interesting to all audiences through a series of interactive-digital sculptures, large-scale photography and field-based videography. While this project is driven by scientific data, it is rooted in deeply artistic and outreach-based practices, which include broad artistic practices, e.g.: digital design, illustration, photography, video and sound design. Using 3D modeling and printing technology MicroEcos centers around a series of 3D-printed models of the Last Canyon rock shelter on the Wyoming and Montana border, Little Windy Hill pond site in Wyoming's Medicine Bow National Forest, and Natural Trap Cave site in Wyoming's Big Horn Basin. These digital, interactive-3D sculpture provide audiences with glimpses of three-dimensional Late-Pleistocene environments, and helps create dialogue of how grass, sagebrush, and spruce based ecosystems form. To help audiences better contextualize how MicroEcos bridges notions of time, space, and place, modern photography and videography of the Last Canyon, Little Windy Hill and Natural Trap Cave sites surround these 3D-digital reconstructions.

  16. Early Pleistocene occurrence of Acheulian technology in North China

    Science.gov (United States)

    Li, Xingwen; Ao, Hong; Dekkers, Mark J.; Roberts, Andrew P.; Zhang, Peng; Lin, Shan; Huang, Weiwen; Hou, Yamei; Zhang, Weihua; An, Zhisheng

    2017-01-01

    Acheulian tools with their associated level of cognizance heralded a major threshold in the evolution of hominin technology, culture and behavior. Thus, unraveling occurrence ages of Acheulian technology across different regions worldwide constitutes a key aspect of understanding the archeology of early human evolution. Here we present a magneto-cyclochronology for the Acheulian assemblage from Sanmenxia Basin, Loess Plateau, North China. Our results place a sequence of stable normal and reversed paleomagnetic polarities within a regional lithostratigraphic context. The Acheulian assemblage is dated to be older than the Matuyama-Brunhes boundary at 0.78 Ma, and is found in strata that are probably equivalent to a weak paleosol subunit within loess layer L9 in the Chinese loess-paleosol sequence, which corresponds to marine isotope stage (MIS) 23, a relatively subdued interglacial period with age range of ∼0.89-0.92 Ma. This age of ∼0.9 Ma implies that Acheulian stone tools were unambiguously present in North China during the Early Pleistocene. It distinctly enlarges the geographic distribution of Acheulian technology and brings its occurrence in North China back into the Early Pleistocene, which is contemporaneous with its first emergence in Europe. Combined with other archeological records, the larger area over which Acheulian technology existed in East Asia during the terminal Early Pleistocene has important implications for understanding early human occupation of North China.

  17. A critical evaluation of the evidence for multiple Late Pleistocene eruptions of Laacher See Volcano

    DEFF Research Database (Denmark)

    Zernack, Anke Verena; Hoggard, Christian Steven; Sauer, Florian Rudolf

    The c. 12,900 BP Plinian eruption of Laacher See Volcano is one of the largest known volcanic events of the Late Pleistocene in the Northern Hemisphere. It buried proximal areas under tens of meters of pyroclastic flow, surge and fallout deposits and deposited a widespread tephra layer across much...... of dispersal of the products from varying eruptive stages and some sites even report two distinct Laacher See Tephra layers that have been interpreted as evidence of a precursor eruption. In order to assess the potential for multiple Late Pleistocene eruptions of Laacher See Volcano, we have compiled...

  18. Late Pleistocene Stratigraphy and Palaeobotany of the Isles of Scilly

    Science.gov (United States)

    Scourse, J. D.

    1991-12-01

    A re-evaluation of the Pleistocene stratigraphy of the Isles of Scilly has enabled the formal definition of eight lithostratigraphic units of member status grouped into two formations. A chronology of events has been provided by radiocarbon (14C) determinations, optical and thermoluminescene (TL) dates. Intersite correlations have been strengthened by palynology, which has aided palaeoenvironmental reconstruction. The defined units have been incorporated into two lithostratigraphic models, one for the `northern' (glacial) Scillies and one for the `southern' (extra-glacial) Scillies. Raised beach sediments of the Watermill Sands and Gravel in the southern Scillies are overlain by the Porthloo Breccia, a unit of soliflucted material derived exclusively from the weathering of local granite. Organic sequences at Carn Morval, Watermill Cove, Porth Askin, Porth Seal and Bread and Cheese Cove occur within the Porthloo Breccia, and are interpreted as the infillings of ponds associated with active solifluction. Radiocarbon determinations from these organic sediments are critical because they pre-date units associated with a glacial event. The 14C determinations indicate deposition of the organic material between 34500-800+885 (Q-2410) and 21500-800+890 (Q-2358) years BP and provide a maximum age for the glacial event and the first radiometric dates for the coastal `head' sediments of southwest England. The pollen assemblages from these organic sites all record open grassland vegetation, and represent the earliest vegetational record for the Scillies. High Pinus values are interpreted as evidence of climatic deterioration. In the southern Scillies, the Porthloo Breccia is overlain by the Old Man Sandloess, a coarse aeolian silt with subdominant fine sand, TL-dated to 18600-3700+3700 years (QTL-ld and lf; Wintle 1981) and optically dated to 20000-7000+7000 and 26000-9000+10000 years (two samples; 738al and 741al; Smith et al. 1990). This material occurs in a variety of facies

  19. Signatures of Late Pleistocene fluvial incision in an Alpine landscape

    Science.gov (United States)

    Leith, Kerry; Fox, Matthew; Moore, Jeffrey R.

    2018-02-01

    Uncertainty regarding the relative efficacy of fluvial and glacial erosion has hindered attempts to quantitatively analyse the Pleistocene evolution of alpine landscapes. Here we show that the morphology of major tributaries of the Rhone River, Switzerland, is consistent with that predicted for a landscape shaped primarily by multiple phases of fluvial incision following a period of intense glacial erosion after the mid-Pleistocene transition (∼0.7 Ma). This is despite major ice sheets reoccupying the region during cold intervals since the mid-Pleistocene. We use high-resolution LiDAR data to identify a series of convex reaches within the long-profiles of 18 tributary channels. We propose these reaches represent knickpoints, which developed as regional uplift raised tributary bedrock channels above the local fluvial baselevel during glacial intervals, and migrated upstream as the fluvial system was re-established during interglacial periods. Using a combination of integral long-profile analysis and stream-power modelling, we find that the locations of ∼80% of knickpoints in our study region are consistent with that predicted for a fluvial origin, while the mean residual error over ∼100 km of modelled channels is just 26.3 m. Breaks in cross-valley profiles project toward the elevation of former end-of-interglacial channel elevations, supporting our model results. Calculated long-term uplift rates are within ∼15% of present-day measurements, while modelled rates of bedrock incision range from ∼1 mm/yr for low gradient reaches between knickpoints to ∼6-10 mm/yr close to retreating knickpoints, typical of observed rates in alpine settings. Together, our results reveal approximately 800 m of regional uplift, river incision, and hillslope erosion in the lower half of each tributary catchment since 0.7 Ma.

  20. Early Pleistocene aquatic resource use in the Turkana Basin.

    Science.gov (United States)

    Archer, Will; Braun, David R; Harris, Jack W K; McCoy, Jack T; Richmond, Brian G

    2014-12-01

    Evidence for the acquisition of nutritionally dense food resources by early Pleistocene hominins has implications for both hominin biology and behavior. Aquatic fauna may have comprised a source of highly nutritious resources to hominins in the Turkana Basin at ∼1.95 Ma. Here we employ multiple datasets to examine the issue of aquatic resource use in the early Pleistocene. This study focuses on four components of aquatic faunal assemblages (1) taxonomic diversity, (2) skeletal element proportion, (3) bone fragmentation and (4) bone surface modification. These components are used to identify associations between early Pleistocene aquatic remains and hominin behavior at the site of FwJj20 in the Koobi Fora Fm. (Kenya). We focus on two dominant aquatic species: catfish and turtles. Further we suggest that data on aquatic resource availability as well as ethnographic examples of aquatic resource use complement our observations on the archaeological remains from FwJj20. Aquatic food items provided hominins with a valuable nutritional alternative to an exclusively terrestrial resource base. We argue that specific advantages afforded by an aquatic alternative to terrestrial resources include (1) a probable reduction in required investment of energy relative to economic return in the form of nutritionally dense food items, (2) a decrease in the technological costs of resource acquisition, and (3) a reduced level of inter-specific competition associated with carcass access and an associated reduction of predation risk relative to terrestrial sources of food. The combined evidence from FwJj20 suggests that aquatic resources may have played a substantial role in early Pleistocene diets and these resources may have been overlooked in previous interpretations of hominin behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

    Science.gov (United States)

    Wu, Xiu-Jie; Xing, Song; Trinkaus, Erik

    2013-01-01

    We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF) in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao) site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right) parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen). In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

  2. An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

    Directory of Open Access Journals (Sweden)

    Xiu-Jie Wu

    Full Text Available We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen. In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

  3. Late Pleistocene and Holocene landscape formation in a gully catchment area in Northern Hesse, Germany

    DEFF Research Database (Denmark)

    Döhler, Susanne; Damm, Bodo; Terhorst, Birgit

    2015-01-01

    the differentiation between Pleistocene and Holocene landforms. Radiocarbon and optically stimulated luminescence dating are applied to add numerical data to the relative ages of the sediments and landforms. The gully channels are oriented along Pleistocene depressions that are built up of periglacial cover beds...... and intercalated reworked loess. As the gully channels cut through the periglacial cover beds, especially the upper layer, the gully system is of Holocene age. At least two phases of gully erosion are identified in the alluvial fan sediments. The initial gully erosion is dated to the time span between the Late......Permanent gully channels under forest are common geomorphological features in Central European low mountain areas. In the Rehgraben/Fuchslöchergraben gully catchment in Northern Hesse, Germany the Late Pleistocene landscape formation is reconstructed based on periglacial cover beds. In addition...

  4. Evidences of climatic variations during Late Pleistocene- Holocene in the eastern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S; Borole, D.V.; Gujar, A; Mascarenhas, A; Mislankar, P.G.; Rao, Ch.M.

    Based upon the variations of clay minerals, sediment texture, heavy mineral assemblage and sup(230)Th excess in the Late Pleistocene sediments of a hemipelagic core from the eastern Bay of Bengal (2713 m water depth), 35 cm and 73-78 cm levels...

  5. External auditory exostoses in the Xuchang and Xujiayao human remains: Patterns and implications among eastern Eurasian Middle and Late Pleistocene crania.

    Science.gov (United States)

    Trinkaus, Erik; Wu, Xiu-Jie

    2017-01-01

    In the context of Middle and Late Pleistocene eastern Eurasian human crania, the external auditory exostoses (EAE) of the late archaic Xuchang 1 and 2 and the Xujiayao 15 early Late Pleistocene human temporal bones are described. Xujiayao 15 has small EAE (Grade 1), Xuchang 1 presents bilateral medium EAE (Grade 2), and Xuchang 2 exhibits bilaterally large EAE (Grade 3), especially on the right side. These cranial remains join the other eastern Eurasian later Pleistocene humans in providing frequencies of 61% (N = 18) and 58% (N = 12) respectively for archaic and early modern human samples. These values are near the upper limits of recent human frequencies, and they imply frequent aquatic exposure among these Pleistocene humans. In addition, the medial extents of the Xuchang 1 and 2 EAE would have impinged on their tympanic membranes, and the large EAE of Xuchang 2 would have resulted in cerumen impaction. Both effects would have produced conductive hearing loss, a serious impairment in a Pleistocene foraging context.

  6. Mineralogical evidence of reduced East Asian summer monsoon rainfall on the Chinese loess plateau during the early Pleistocene interglacials

    Science.gov (United States)

    Meng, Xianqiang; Liu, Lianwen; Wang, Xingchen T.; Balsam, William; Chen, Jun; Ji, Junfeng

    2018-03-01

    The East Asian summer monsoon (EASM) is an important component of the global climate system. A better understanding of EASM rainfall variability in the past can help constrain climate models and better predict the response of EASM to ongoing global warming. The warm early Pleistocene, a potential analog of future climate, is an important period to study EASM dynamics. However, existing monsoon proxies for reconstruction of EASM rainfall during the early Pleistocene fail to disentangle monsoon rainfall changes from temperature variations, complicating the comparison of these monsoon records with climate models. Here, we present three 2.6 million-year-long EASM rainfall records from the Chinese Loess Plateau (CLP) based on carbonate dissolution, a novel proxy for rainfall intensity. These records show that the interglacial rainfall on the CLP was lower during the early Pleistocene and then gradually increased with global cooling during the middle and late Pleistocene. These results are contrary to previous suggestions that a warmer climate leads to higher monsoon rainfall on tectonic timescales. We propose that the lower interglacial EASM rainfall during the early Pleistocene was caused by reduced sea surface temperature gradients across the equatorial Pacific, providing a testable hypothesis for climate models.

  7. Sedimentary architecture and chronostratigraphy of a late Quaternary incised-valley fill: A case study of the late Middle and Late Pleistocene Rhine system in the Netherlands

    Science.gov (United States)

    Peeters, J.; Busschers, F. S.; Stouthamer, E.; Bosch, J. H. A.; Van den Berg, M. W.; Wallinga, J.; Versendaal, A. J.; Bunnik, F. P. M.; Middelkoop, H.

    2016-01-01

    This paper describes the sedimentary architecture, chronostratigraphy and palaeogeography of the late Middle and Late Pleistocene (Marine Isotope Stage/MIS 6-2) incised Rhine-valley fill in the central Netherlands based on six geological transects, luminescence dating, biostratigraphical data and a 3D geological model. The incised-valley fill consists of a ca. 50 m thick and 10-20 km wide sand-dominated succession and includes a well-developed sequence dating from the Last Interglacial: known as the Eemian in northwest Europe. The lower part of the valley fill contains coarse-grained fluvio-glacial and fluvial Rhine sediments that were deposited under Late Saalian (MIS 6) cold-climatic periglacial conditions and during the transition into the warm Eemian interglacial (MIS 5e-d). This unit is overlain by fine-grained fresh-water flood-basin deposits, which are transgressed by a fine-grained estuarine unit that formed during marine high-stand. This ca. 10 m thick sequence reflects gradual drowning of the Eemian interglacial fluvial Rhine system and transformation into an estuary due to relative sea-level rise. The chronological data suggests a delay in timing of regional Eemian interglacial transgression and sea-level high-stand of several thousand years, when compared to eustatic sea-level. As a result of this glacio-isostatic controlled delay, formation of the interglacial lower deltaic system took only place for a relative short period of time: progradation was therefore limited. During the cooler Weichselian Early Glacial period (MIS 5d-a) deposition of deltaic sediments continued and extensive westward progradation of the Rhine system occurred. Major parts of the Eemian and Weichselian Early Glacial deposits were eroded and buried as a result of sea-level lowering and climate cooling during the early Middle Weichselian (MIS 4-3). Near complete sedimentary preservation occurred along the margins of the incised valley allowing the detailed reconstruction presented

  8. The British Lower Palaeolithic of the early Middle Pleistocene

    Science.gov (United States)

    Hosfield, Robert

    2011-06-01

    The archaeology of Britain during the early Middle Pleistocene (MIS 19-12) is represented by a number of key sites across eastern and southern England. These sites include Pakefield, Happisburgh 1, High Lodge, Warren Hill, Waverley Wood, Boxgrove, Kent's Cavern, and Westbury-sub-Mendip, alongside a 'background scatter' lithic record associated with the principal river systems (Bytham, pre-diversion Thames, and Solent) and raised beaches (Westbourne-Arundel). Hominin behaviour can be characterised in terms of: preferences for temperate or cool temperate climates and open/woodland mosaic habitats (indicated by mammalian fauna, mollusca, insects, and sediments); a biface-dominated material culture characterised by technological diversity, although with accompanying evidence for distinctive core and flake (Pakefield) and flake tool (High Lodge) assemblages; probable direct hunting-based subsistence strategies (with a focus upon large mammal fauna); and generally locally-focused spatial and landscape behaviours (principally indicated by raw material sources data), although with some evidence of dynamic, mobile and structured technological systems. The British data continues to support a 'modified short chronology' to the north of the Alps and the Pyrenees, with highly sporadic evidence for a hominin presence prior to 500-600 ka, although the ages of key assemblages are subject to ongoing debates regarding the chronology of the Bytham river terraces and the early Middle Pleistocene glaciations of East Anglia.

  9. Large Late Pleistocene landslides from the marginal slope of the Flysch Carpathians

    Czech Academy of Sciences Publication Activity Database

    Pánek, T.; Hartvich, Filip; Jankovská, Vlasta; Klimeš, Jan; Tábořík, Petr; Bubík, M.; Smolková, V.; Hradecký, J.

    2014-01-01

    Roč. 11, č. 6 (2014), s. 981-992 ISSN 1612-510X R&D Projects: GA MŠk LM2010008 Institutional support: RVO:67985891 ; RVO:67985939 Keywords : fossil landslide * radiocarbon dating * electrical resistivity tomography * pollen analysis * Late Pleistocene * Flysch Carpathians * Marine Isotope Stage 3 Subject RIV: DE - Earth Magnetism, Geodesy, Geography; EF - Botanics (BU-J) Impact factor: 2.870, year: 2014

  10. Sedimentologic and paleontologic study of the southeast coast of Buenos Aires province, Argentina: A late Pleistocene Holocene paleoenvironmental reconstruction

    Science.gov (United States)

    Aramayo, S. A.; Téllez, B. Gutiérrez; Schillizzi, R. A.

    2005-10-01

    A paleoenvironmental reconstruction of the southeast coast of Buenos Aires province, Argentina, is made mainly on the basis of paleontological and paleoichnological studies, supported by sedimentological analyses and radiocarbon dating. Continental late Pleistocene and continental, transitional, and marine Holocene stratigraphic units are identified. The former comprises fossil mammals and ichnites of 16000-12,000 BP. The continental early Holocene time, ca. 8100 BP, is represented by an interdune paleoenvironment in which shallow brackish ponds were colonized by diatoms, fish, rodents, and birds. A transitional paleoenvironment in the middle Holocene—6930-6570 BP—is recorded by deposits formed by estuarine crabs. During the late Holocene, between 5000 and 4800 BP, a marine transgression was recorded by a rich mollusc fauna.

  11. Cheek tooth morphology and ancient mitochondrial DNA of late Pleistocene horses from the western interior of North America: Implications for the taxonomy of North American Late Pleistocene Equus.

    Directory of Open Access Journals (Sweden)

    Christina I Barrón-Ortiz

    Full Text Available Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to the end-Pleistocene extinction. Based on the morphological and molecular data analyzed, a caballine (Equus ferus and a non-caballine (E. conversidens species were identified from different localities across most of the Western Interior. A second non-caballine species (E. cedralensis was recognized from southern localities based exclusively on the morphological analyses of the cheek teeth. Notably the separation into caballine and non-caballine species was observed in the Bayesian phylogenetic analysis of ancient mtDNA as well as in the geometric morphometric analyses of the upper and lower premolars. Teeth morphologically identified as E. conversidens that yielded ancient mtDNA fall within the New World stilt-legged clade recognized in previous studies and this is the name we apply to this group. Geographic variation in morphology in the caballine species is indicated by statistically different occlusal enamel patterns in the specimens from Bluefish Caves, Yukon Territory, relative to the specimens from the other geographic regions. Whether this represents ecomorphological variation and/or a certain degree of geographic and genetic isolation of these Arctic populations requires further study.

  12. Early and Late Retirement Exits

    Science.gov (United States)

    Brougham, Ruby R.; Walsh, David A.

    2009-01-01

    The current study proposes that personal need fulfillment (relatedness, generativity, identity, growth, and finances) predicts early and late retirement intentions. The personal needs of 160 full-time older employees were measured by personal goals, job satisfactions, job characteristics, and intrinsic motivation. Results suggest that the personal…

  13. Reconstruction of Late Pleistocene Paleoenvironments using bulk geochemistry of paleosols from the Lake Victoria Region

    Science.gov (United States)

    Beverly, Emily J.; Peppe, Daniel J.; Driese, Steven G.; Blegen, Nick; Faith, J. Tyler; Tryon, Christian A.; Stinchcomb, Gary E.

    2017-11-01

    The impact of changing environments on the evolution and dispersal of Homo sapiens is highly debated, but few data are available from equatorial Africa. Lake Victoria is the largest freshwater lake in the tropics and is currently a biogeographic barrier between the eastern and western branches of the East African Rift. The lake has previously desiccated at 17 ka and again at 15 ka, but little is known from this region prior to the Last Glacial Maximum. The Pleistocene terrestrial deposits on the northeast coast of Lake Victoria (94 to 36 ka) are ideal for paleoenvironmental reconstructions where volcaniclastic deposits (tuffs), fluvial deposits, tufa, and paleosols are exposed, which can be used to reconstruct Critical Zones (CZ) of the past (paleo-CZs). The paleo-CZ is a holistic concept that reconstructs the entire landscape using geologic records of the atmosphere, hydrosphere, lithosphere, biosphere, and pedosphere (the focus of this study). New paleosol-based mean annual precipitation (MAP) proxies from Karungu, Rusinga Island, and Mfangano Island indicate an average MAP of 750108 mm yr-1 (CALMAG), 800182 mm yr-1 (CIA-K), and 1010228 mm yr-1 (PPM1.0) with no statistical difference throughout the 11 m thick sequence. This corresponds to between 54 and 72% of modern precipitation. Tephras bracketing these paleosols have been correlated across seven sites, and sample a regional paleo-CZ across a 55 km transect along the eastern shoreline of the modern lake. Given the sensitivity of Lake Victoria to precipitation, it is likely that the lake was significantly smaller than modern between 94 ka and 36 ka. This would have removed a major barrier for the movement of fauna (including early modern humans) and provided a dispersal corridor across the equator and between the rifts. It is also consistent with the associated fossil faunal assemblage indicative of semi-arid grasslands. During the Late Pleistocene, the combined geologic and paleontological evidence suggests a

  14. Reconstruction of Late Pleistocene Paleoenvironments Using Bulk Geochemistry of Paleosols from the Lake Victoria Region

    Directory of Open Access Journals (Sweden)

    Emily J. Beverly

    2017-11-01

    Full Text Available The impact of changing environments on the evolution and dispersal of Homo sapiens is highly debated, but few data are available from equatorial Africa. Lake Victoria is the largest freshwater lake in the tropics and is currently a biogeographic barrier between the eastern and western branches of the East African Rift. The lake has previously desiccated at ~17 ka and again at ~15 ka, but little is known from this region prior to the Last Glacial Maximum. The Pleistocene terrestrial deposits on the northeast coast of Lake Victoria (94–36 ka are ideal for paleoenvironmental reconstructions where volcaniclastic deposits (tuffs, fluvial deposits, tufa, and paleosols are exposed, which can be used to reconstruct Critical Zones (CZ of the past (paleo-CZs. The paleo-CZ is a holistic concept that reconstructs the entire landscape using geologic records of the atmosphere, hydrosphere, lithosphere, biosphere, and pedosphere (the focus of this study. New paleosol-based mean annual precipitation (MAP proxies from Karungu, Rusinga Island, and Mfangano Island indicate an average MAP of 750 ± 108 mm year−1 (CALMAG, 800 ± 182 mm year−1 (CIA-K, and 1,010 ± 228 mm year−1 (PPM1.0 with no statistical difference throughout the 11 m thick sequence. This corresponds to between 54 and 72% of modern precipitation. Tephras bracketing these paleosols have been correlated across seven sites, and sample a regional paleo-CZ across a ~55 km transect along the eastern shoreline of the modern lake. Given the sensitivity of Lake Victoria to precipitation, it is likely that the lake was significantly smaller than modern between 94 and 36 ka. This would have removed a major barrier for the movement of fauna (including early modern humans and provided a dispersal corridor across the equator and between the rifts. It is also consistent with the associated fossil faunal assemblage indicative of semi-arid grasslands. During the Late Pleistocene, the combined geologic and

  15. The Late Pleistocene distribution of vicuñas (Vicugna vicugna) and the “extinction” of the gracile llama (“Lama gracilis”): New molecular data

    Science.gov (United States)

    Weinstock, Jaco; Shapiro, Beth; Prieto, Alfredo; Marín, Juan Carlos; González, Benito A.; Gilbert, M. Thomas P.; Willerslev, Eske

    2009-07-01

    We present the results of a palaeogenetic analysis of two Late Pleistocene camelids originating in southern Chile. Our analysis of two mitochondrial DNA fragments (control region and cytochrome b gene) reveals that these specimens do not belong to an extinct taxon, but rather to extant vicuña ( Vicugna vicugna), whose modern distribution is restricted to the extreme elevations of the Andes, more than 3500 km to the north of where these specimens originated. Our results also suggest fossil specimens from Patagonia that are currently assigned to the extinct taxon Lama gracilis, may actually belong to V. vicugna, implying a continuous distribution of the latter from the southern tip of South America to the Andes during the Final Pleistocene. The haplotypes of both specimens are not present in modern populations, suggesting a loss of genetic diversity concomitant with the contraction of the vicuña geographical distribution during the Final Pleistocene or early Holocene.

  16. Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

    Science.gov (United States)

    Kupczik, Kornelius; Hublin, Jean-Jacques

    2010-11-01

    Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. People of the ancient rainforest: late Pleistocene foragers at the Batadomba-lena rockshelter, Sri Lanka.

    Science.gov (United States)

    Perera, Nimal; Kourampas, Nikos; Simpson, Ian A; Deraniyagala, Siran U; Bulbeck, David; Kamminga, Johan; Perera, Jude; Fuller, Dorian Q; Szabó, Katherine; Oliveira, Nuno V

    2011-09-01

    Batadomba-lena, a rockshelter in the rainforest of southwestern Sri Lanka, has yielded some of the earliest evidence of Homo sapiens in South Asia. H. sapiens foragers were present at Batadomba-lena from ca. 36,000 cal BP to the terminal Pleistocene and Holocene. Human occupation was sporadic before the global Last Glacial Maximum (LGM). Batadomba-lena's Late Pleistocene inhabitants foraged for a broad spectrum of plant and mainly arboreal animal resources (monkeys, squirrels and abundant rainforest snails), derived from a landscape that retained equatorial rainforest cover through periods of pronounced regional aridity during the LGM. Juxtaposed hearths, palaeofloors with habitation debris, postholes, excavated pits, and animal and plant remains, including abundant Canarium nutshells, reflect intensive habitation of the rockshelter in times of monsoon intensification and biome reorganisation after ca. 16,000 cal BP. This period corresponds with further broadening of the economic spectrum, evidenced though increased contribution of squirrels, freshwater snails and Canarium nuts in the diet of the rockshelter occupants. Microliths are more abundant and morphologically diverse in the earliest, pre-LGM layer and decline markedly during intensified rockshelter use on the wane of the LGM. We propose that changing toolkits and subsistence base reflect changing foraging practices, from shorter-lived visits of highly mobile foraging bands in the period before the LGM, to intensified use of Batadomba-lena and intense foraging for diverse resources around the site during and, especially, following the LGM. Traces of ochre, marine shell beads and other objects from an 80 km-distant shore, and, possibly burials reflect symbolic practices from the outset of human presence at the rockshelter. Evidence for differentiated use of space (individual hearths, possible habitation structures) is present in LGM and terminal Pleistocene layers. The record of Batadomba-lena demonstrates

  18. Paleolimnological reconstruction of environmental variability during the Late Pleistocene and Holocene in the south-east Baltic region

    Science.gov (United States)

    Kublitskiy, Iurii; Subetto, Dmitriy; Druzhinina, Olga; Kulkova, Marianna; Arslanov, Khikmatula

    2016-04-01

    Kamyshovoe Lake : history of vegetation during late Pleistocene and early Holocene (Kaliningrad District, Russia). Baltica, 28 (2). (in press). Kublitskiy, I., Subetto, D., Kulkova, M., Druzhinina, O., Arslanov, Kh., 2015. Analysis of the climatic changes at the Late Pleistocene and the Holocene based on palaeolimnological studies of the Kamyshovoe Lake (Kaliningrad Region). Proceeding of the IX Russian conference on Quaternary Research (Irkutsk, 15-20 September 2015) [In Russian].

  19. Human influence on distribution and extinctions of the late Pleistocene Eurasian megafauna.

    Science.gov (United States)

    Pushkina, Diana; Raia, Pasquale

    2008-06-01

    Late Pleistocene extinctions are of interest to paleontological and anthropological research. In North America and Australia, human occupation occurred during a short period of time and overexploitation may have led to the extinction of mammalian megafauna. In northern Eurasia megafaunal extinctions are believed to have occurred over a relatively longer period of time, perhaps as a result of changing environmental conditions, but the picture is much less clear. To consider megafaunal extinction in Eurasia, we compare differences in the geographical distribution and commonness of extinct and extant species between paleontological and archaeological localities from the late middle Pleistocene to Holocene. Purely paleontological localities, as well as most extinct species, were distributed north of archaeological sites and of the extant species, suggesting that apart from possible differences in adaptations between humans and other species, humans could also have a detrimental effect on large mammal distribution. However, evidence for human overexploitation applies only to the extinct steppe bison Bison priscus. Other human-preferred species survive into the Holocene, including Rangifer tarandus, Equus ferus, Capreolus capreolus, Cervus elaphus, Equus hemionus, Saiga tatarica, and Sus scrofa. Mammuthus primigenius and Megaloceros giganteus were rare in archaeological sites. Carnivores appear little influenced by human presence, although they become rarer in Holocene archaeological sites. Overall, the data are consistent with the conclusion that humans acted as efficient hunters selecting for the most abundant species. Our study supports the idea that the late Pleistocene extinctions were environmentally driven by climatic changes that triggered habitat fragmentation, species range reduction, and population decrease, after which human interference either by direct hunting or via indirect activities probably became critical.

  20. Synchronous genetic turnovers across Western Eurasia in Late Pleistocene collared lemmings.

    Science.gov (United States)

    Palkopoulou, Eleftheria; Baca, Mateusz; Abramson, Natalia I; Sablin, Mikhail; Socha, Paweł; Nadachowski, Adam; Prost, Stefan; Germonpré, Mietje; Kosintsev, Pavel; Smirnov, Nickolay G; Vartanyan, Sergey; Ponomarev, Dmitry; Nyström, Johanna; Nikolskiy, Pavel; Jass, Christopher N; Litvinov, Yuriy N; Kalthoff, Daniela C; Grigoriev, Semyon; Fadeeva, Tatyana; Douka, Aikaterini; Higham, Thomas F G; Ersmark, Erik; Pitulko, Vladimir; Pavlova, Elena; Stewart, John R; Węgleński, Piotr; Stankovic, Anna; Dalén, Love

    2016-05-01

    Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D. torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next-generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D. torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50 000 years. The observation of repeated extinctions across such a vast geographical range indicates large-scale changes in the steppe-tundra environment in western Eurasia during the last glaciation. All Holocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D. torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D. groenlandicus and D. richardsoni were recovered from a Late Pleistocene site in south-western Canada. This suggests that D. groenlandicus had a more southern and D. richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex

  1. LATE PLEISTOCENE RODENTS (MAMMALIA: RODENTIA FROM THE BARANICA CAVE NEAR KNJAZEVAC (EASTERN SERBIA: SYSTEMATICS AND PALAEOECOLOGY

    Directory of Open Access Journals (Sweden)

    KATARINA BOGICEVIC

    2011-07-01

    Full Text Available Baranica is a cave in the Balkan mountain range in the eastern part of Serbia. It contains four layers of sediments of Quaternary age. The Upper Pleistocene deposits (layers 2-4 have yielded a rich and diverse assemblage of vertebrate fauna, including fish, amphibians, reptiles, birds, and small and large mammals. In this work, preliminary results of a study of the rodent fauna from the Upper Pleistocene deposits of the Baranica Cave (Knjazevac, eastern Serbia are presented. The fossil material comes from the 1995 archaeological excavation. The remains of 10 rodent species are described herein: Spermophilus cf. citelloides, Castor fiber, Sicista subtilis, Cricetulus migratorius, Cricetus cricetus, Mesocricetus newtoni, Apodemus ex gr. sylvaticus-flavicollis, Spalax leucodon, Dryomys nitedula, and Muscardinus avellanarius. Along with eight vole species, this makes altogether 18 species of rodents found in this locality. Both layers 2 and 4 (layer 3 is very poor in fossils have yielded a rodent fauna typical for the cold periods of the Late Pleistocene on the Balkan Peninsula, with a prevalence of open and steppe inhabitants, but some forest dwellers were also present. The assemblages from these layers are similar, but there are some differences in the composition of the fauna, which may indicate a slight shift towards drier conditions. They have also been compared to rodent associations from some Serbian and Bulgarian localities of the same age and their similarities and differences are discussed. SHORT NOTE-NOTA BREVE

  2. The late Pleistocene glacial sequence in the middle Maruia valley, southeast Nelson, New Zealand

    International Nuclear Information System (INIS)

    Mabin, M.C.G.

    1983-01-01

    Glacial and fluvioglacial landforms and deposits preserved in the middle reaches of the Maruia valley, southeast Nelson, New Zealand, record the activity of the Maruia glacier during the late Pleistocene Otira Glaciation. Five advances are recognised, from oldest to youngest: Creighton 1, 2, 3, and the Reid Stream 1, 2 advances. There was an interstadial interval between the Creighton 3 and Reid Stream 1 advances. The Reid Stream 1 advance occurred shortly after 14 800 years B.P. (NZ536, old T/sub 0.5/). (auths)

  3. U-series component dating for late pleistocene basalt Longgang, Jilin province

    International Nuclear Information System (INIS)

    Yu Fusheng; Yuan Wanming; Han Song

    2003-01-01

    Longgang volcanic swarm belongs to one of volcanic areas which have been active since modern times. In view of multiple eruptions during histories, it is very important to determine age of every eruption for evaluating volcanic hazards. The alkaline basalt samples taken from Dayizishan and diaoshuihu are analyzed by U-series component method, after magnetic separation. The ages of the two samples are (71 ± 9) ka, (106 ± 13) ka before presence, respectively. These data indicate that there exist intensively eruptive activities during late Pleistocene

  4. Phylogeography of the Alcippe morrisonia (Aves: Timaliidae: long population history beyond late Pleistocene glaciations

    Directory of Open Access Journals (Sweden)

    Li Shouhsien

    2009-06-01

    Full Text Available Abstract Background The role of Pleistocene glacial oscillations in current biodiversity and distribution patterns varies with latitude, physical topology and population life history and has long been a topic of discussion. However, there had been little phylogeographical research in south China, where the geophysical complexity is associated with great biodiversity. A bird endemic in Southeast Asia, the Grey-cheeked Fulvetta, Alcippe morrisonia, has been reported to show deep genetic divergences among its seven subspecies. In the present study, we investigated the phylogeography of A. morrisonia to explore its population structure and evolutionary history, in order to gain insight into the effect of geological events on the speciation and diversity of birds endemic in south China. Results Mitochondrial genes cytochrome b (Cytb and cytochrome c oxidase I (COI were represented by 1236 nucleotide sites from 151 individuals from 29 localities. Phylogenetic analysis showed seven monophyletic clades congruent with the geographically separated groups, which were identified as major sources of molecular variance (90.92% by AMOVA. TCS analysis revealed four disconnected networks, and that no haplotype was shared among the geographical groups. The common ancestor of these populations was dated to 11.6 Mya and several divergence events were estimated along the population evolutionary history. Isolation by distance was inferred by NCPA to be responsible for the current intra-population genetic pattern and gene flow among geographical groups was interrupted. A late Pleistocene demographic expansion was detected in the eastern geographical groups, while the expansion time (0.2–0.4 Mya was earlier than the Last Glacial Maximum. Conclusion It is proposed that the complicated topology preserves high genetic diversity and ancient lineages for geographical groups of A. morrisonia in China mainland and its two major islands, and restricts gene exchange during

  5. Revision of the early Middle Pleistocene bears (Ursidae, Mammalia) of Central Europe, with special respect to possible co-occurrence of spelaeoid and arctoid lineages

    Czech Academy of Sciences Publication Activity Database

    Wagner, J.; Čermák, Stanislav

    2012-01-01

    Roč. 87, č. 3 (2012), s. 461-496 ISSN 1214-1119 Institutional research plan: CEZ:AV0Z30130516 Keywords : Ursus deningeri * U. arctos, * Late Biharian * Early Toringian * Middle Pleistocene Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.141, year: 2012 http://www.geology.cz/bulletin/fulltext/1354_Wagner.pdf

  6. Modeling the imprint of Milankovitch cycles on early Pleistocene ice volume

    Science.gov (United States)

    Roychowdhury, R.; DeConto, R.; Pollard, D.

    2017-12-01

    Global climate during Quaternary and Late Pliocene (present-3.1 Ma) is characterized by alternating glacial and interglacial conditions. Several proposed theories associate these cycles with variations in the Earth's orbital configuration. In this study, we attempt to address the anomalously strong obliquity forcing in the Late Pliocene/Early Pleistocene ice volume records (41 kyr world), which stands in sharp contrast to the primary cyclicity of insolation, which is at precessional periods (23 kyr). Model results from GCM simulations show that at low eccentricities (e0.015), precessional response is important, and the insolation metrics vary out-of-phase between the two hemispheres. Using simulations from a GCM-driven ice sheet model, we simulate time continuous ice volume changes from Northern and Southern Hemispheres. Under eccentricities lower than 0.015, ice sheets in both hemispheres respond only to obliquity cycle, and grow and melt together (in-phase). If the ice sheet is simulated with eccentricity higher than 0.015, both hemispheres become more sensitive to precessional variation, and vary out-of-phase with each other, which is consistent with proxy observations from the late Pleistocene glaciations. We use the simulated ice volumes from 2.0 to 1.0 ma to empirically calculate global benthic δ18O variations based on the assumption that relationships between collapse and growth of ice-sheets and sea level is linear and symmetric and that the isotopic signature of the individual ice-sheets has not changed with time. Our modeled global benthic δ18O values are broadly consistent with the paleoclimate proxy records such as the LR04 stack.

  7. The diversity and biogeography of late Pleistocene birds from the lowland Neotropics

    Science.gov (United States)

    Steadman, David W.; Oswald, Jessica A.; Rincón, Ascanio D.

    2015-05-01

    The Neotropical lowlands sustain the world's richest bird communities, yet little that we know about their history is based on paleontology. Fossils afford a way to investigate distributional shifts in individual species, and thus improve our understanding of long-term change in Neotropical bird communities. We report a species-rich avian fossil sample from a late Pleistocene tar seep (Mene de Inciarte) in northwestern Venezuela. A mere 175 identified fossils from Mene de Inciarte represent 73 species of birds, among which six are extinct, and eight others no longer occur within 100 km. These 14 species consist mainly of ducks (Anatidae), snipe (Scolopacidae), vultures/condors (Vulturidae), hawks/eagles (Accipitridae), and blackbirds (Icteridae). Neotropical bird communities were richer in the late Pleistocene than today; their considerable extinction may be related to collapse of the large mammal fauna at that time. The species assemblage at Mene de Inciarte suggests that biogeographic patterns, even at continental scales, have been remarkably labile over short geological time frames. Mene de Inciarte is but one of 300 + tar seeps in Venezuela, only two of which have been explored for fossils. We may be on the cusp of an exciting new era of avian paleontology in the Neotropics.

  8. Fossil woods of Detarioideae subfamily (Fabaceae) from El Palmar Formation (Late Pleistocene) in South America

    Science.gov (United States)

    Ramos, R. Soledad; Brea, Mariana; Kröhling, Daniela M.

    2017-11-01

    The main aim of the present paper is to describe the first Detarioideae fossil woods from El Palmar Formation (Late Pleistocene) in the Uruguay River Basin (Entre Ríos, Argentina). This study is based on five silicified wood specimens preserved in fluvial deposits, which were transported from their growth site. Two new genera and species are described: Paraoxystigma concordiensis gen. nov and sp. nov. has medium-sized vessels, paratracheal axial parenchyma, heterocellular and multiseriate rays, and diffuse axial canals similar in size and shape to vessels, and Gossweilerodendroxylon palmariensis gen. nov and sp. nov. has medium-sized vessels, alternate intervessel pits, paratracheal and apotracheal axial parenchyma, homocellular and uni to-multiseriate rays, and small diffuse axial canals. These Detarioideae fossil records in south-eastern South America support the existence of a very old relationship with the extant West African forests. Eco-anatomical features observed in these fossil woods, along with the climatic information available from the Nearest Living Relatives (NLRs) comparison, suggest warm and humid climatic conditions for the upper-middle basin of the Uruguay River during some periods of the Late Pleistocene.

  9. Late Pleistocene ecological, environmental and climatic reconstruction based on megafauna stable isotopes from northwestern Chilean Patagonia

    Science.gov (United States)

    González-Guarda, Erwin; Domingo, Laura; Tornero, Carlos; Pino, Mario; Hernández Fernández, Manuel; Sevilla, Paloma; Villavicencio, Natalia; Agustí, Jordi

    2017-08-01

    Stable isotope analyses have been performed on the bioapatite (δ13C; δ18O) and collagen (δ13C; δ15N) of four late Pleistocene South American megafaunal taxa (Notiomastodon platensis, Equus andium, cf. Hemiauchenia paradoxa and Xenarthra indet.) to evaluate paleoclimatic and paleoenvironmental conditions as well as paleoecological features of this time period. The analyzed megafauna was found at several locations in the northwestern Chilean Patagonia (38°-42°S, 74°-71°W). The bioapatite δ13C values indicated the presence of C3 vegetation ranging from forestal to woodland areas. The collagen δ15N values pointed to temperate and humid ecosystems, and to the consumption of shrubs, trees, grasses and sedges. Mean annual temperatures estimated from bioapatite δ18OPO4 values show a similarity to modern temperatures and suggested that the megafauna under study may have lived during warm stages (interstadials) of the late Pleistocene. When comparing our results with those obtained from other South American regions, we find that the diet of this particular Chilean megafauna appears to have been more influenced by resource availability than by the potential dietary range of the taxa.

  10. A Pathological Late Pleistocene canid from San Sidero (Italy): implications for social- and feeding-behaviour

    Science.gov (United States)

    Iurino, Dawid Adam; Fico, Rosario; Petrucci, Mauro; Sardella, Raffaele

    2013-03-01

    Evidence of diseases on vertebrate fossil bones can provide detailed information on many aspects of extinct animals. This study focused on pathological craniodental remains (left maxilla and dentary) referred to the canid Cuon alpinus unearthed from a Late Pleistocene karst filling deposit at San Sidero (Apulia, southern Italy). These fossils show clear evidence of a chronic periodontitis that caused the animal's death. Clinical diagnosis of the disease and the timing of its development have been defined on the basis of a veterinary odontostomatology approach, in addition to radiographic and tomographic techniques. From the initiation of the infection until death, a time span of at least 6 months occurred, and three main steps have been defined: (1) the bacterial infections of the buccal cavity turning into severe periodontitis, (2) the fracture of the lower carnassial and (3) the loss of teeth due to the worsening infection that deformed and/or eroded maxillary and mandibular bones and enlarged alveoli. The analysis of the palaeopathology also provides information about the biomechanics of the bite, on the feeding behaviour and on the relationships of injured members in a pack of Late Pleistocene canids.

  11. Rodent burrows in late Pleistocene paleosols at Korean Palaeolithic sites and their implications for paleoclimate changes

    Science.gov (United States)

    Lim, H.; Park, S.; Lee, J.; Lee, Y.

    2013-12-01

    Rodent burrows are commonly found at many Paleolithic archaeological sites in Korea. They are nearly straight in horizontal view and gently inclined in lateral view. Burrow diameters are mostly 7 - 10cm, and burrow length may reach a few meters. Vertical penetration depths are generally about 1 m from the surface, and the thickness of the burrow-bearing layer is about 1-2 m. Although no remains (bones, teeth, claws, and coprolites) were found within burrows, they are interpreted to have been produced by rodent-like mammals (probably ground squirrels) based on the size and architecture. According to the previous study, the age of these burrows was constrained to be between ca. 40,000 and 25,000 yr BP by tephrochronology, radiocarbon and optically stimulated luminescence dating results (Lim et al., 2007). However, little is known about the reason why these burrows have disappeared after late Pleistocene time. For this question, two explanations can be considered: extinction or migration. Since same kinds of burrows are still found in the high-latitude regions, such as Mongolia and North America, the possibility of extinction can be ruled out. Therefore, migration seems to be the most likely explanation. Our results show that the destruction of habitat caused by climate change during this period is the main reason for the northward migration of burrowing animals. This study suggests that rodent burrows found in the late Pleistocene paleosols can provide useful information on paleoclimate and paleoenvironmental changes.

  12. Earthquake-induced soft-sediment deformation structures in Late Pleistocene lacustrine deposits of Issyk-Kul lake (Kyrgyzstan)

    Science.gov (United States)

    Gladkov, A. S.; Lobova, E. U.; Deev, E. V.; Korzhenkov, A. M.; Mazeika, J. V.; Abdieva, S. V.; Rogozhin, E. A.; Rodkin, M. V.; Fortuna, A. B.; Charimov, T. A.; Yudakhin, A. S.

    2016-10-01

    This paper discusses the composition and distribution of soft-sediment deformation structures induced by liquefaction in Late Pleistocene lacustrine terrace deposits on the southern shore of Issyk-Kul Lake in the northern Tien Shan mountains of Kyrgyzstan. The section contains seven deformed beds grouped in two intervals. Five deformed beds in the upper interval contain load structures (load casts and flame structures), convolute lamination, ball-and-pillow structures, folds and slumps. Deformation patterns indicate that a seismic trigger generated a multiple slump on a gentle slope. The dating of overlying subaerial deposits suggests correlation between the deformation features and strong earthquakes in the Late Pleistocene.

  13. Reconsideration of the systematics of the Early Pleistocene Cervavitus (Cervidae, Artiodactyla, Mammalia

    Directory of Open Access Journals (Sweden)

    Dong, W.

    2011-12-01

    Full Text Available Cervavitus were usually found from the Late Miocene and Pliocene deposits in East Europe, Middle Asia and North China, but they were found recently in many Early Pleistocene localities in southern China. The latter resulted in the discussion of their systematic status between Cervavitus and Cervus. Here we show the Early Pleistocene forms from southern China are morphometrically more similar to northern China Cervavitus species, and the cladistic analysis shows that the southern China forms are closer to classic Cervavitus species than Cervus and that also proves their systematic status in Cervavitus rather than in Cervus. Cervavitus originated in Moldovan forests of East Europe in the late Vallesian (MN10 from a brachyodont and holometacarpal ancestor with two/three-tined antlers and Palaeomeryx fold and evolved into C. novorossiae. It dispersed into West Europe forests in the earliest Turolian and further west to France in the Ruscinian. It dispersed into northern China forests in the early Turolian and represented by C. shanxius. The great quantity of C. shanxius specimens with brachyodont teeth and complete lateral metacarpals implies the arid Loess Plateau of today was a humid forested region in the Late Miocene. C. shanxius migrated southwards in the Plio-Pleistocene probably due to the drying environment in northern China with uplifting of Himalayas and evolved into C. ultimus and C. fenqii, which survived in southern China until the Early Pleistocene (MNQ18.La revisión sistemática de Cervivatus sugiere que deriva del principal clado de los cérvidos posteriores a los muntiacinos, e implica que Procervulinae, Dicrocerinae y la primeras formas de Munticiacinae serían holometacarpales, como también lo es Cervivatus, originario en los bosques de Moldavia (Europa del Este durante el Vallesiense final (MN 10, a partir de un antecesor braquiodonto y holometacarpal, con astas con dos o tres candiles y pliegue paleomerícido, y que da lugar a

  14. Direct radiocarbon dates for Vindija G1 and Velika Pećina Late Pleistocene hominid remains

    Science.gov (United States)

    Smith, Fred H.; Trinkaus, Erik; Pettitt, Paul B.; Karavanić, Ivor; Paunović, Maja

    1999-01-01

    New accelerator mass spectrometry radiocarbon dates taken directly on human remains from the Late Pleistocene sites of Vindija and Velika Pećina in the Hrvatsko Zagorje of Croatia are presented. Hominid specimens from both sites have played critical roles in the development of current perspectives on modern human evolutionary emergence in Europe. Dates of ≈28 thousand years (ka) before the present (B.P.) and ≈29 ka B.P. for two specimens from Vindija G1 establish them as the most recent dated Neandertals in the Eurasian range of these archaic humans. The human frontal bone from Velika Pećina, generally considered one of the earliest representatives of modern humans in Europe, dated to ≈5 ka B.P., rendering it no longer pertinent to discussions of modern human origins. Apart from invalidating the only radiometrically based example of temporal overlap between late Neandertal and early modern human fossil remains from within any region of Europe, these dates raise the question of when early modern humans first dispersed into Europe and have implications for the nature and geographic patterning of biological and cultural interactions between these populations and the Neandertals. PMID:10535913

  15. Middle Pleistocene protein sequences from the rhinoceros genus Stephanorhinus and the phylogeny of extant and extinct Middle/Late Pleistocene Rhinocerotidae.

    Science.gov (United States)

    Welker, Frido; Smith, Geoff M; Hutson, Jarod M; Kindler, Lutz; Garcia-Moreno, Alejandro; Villaluenga, Aritza; Turner, Elaine; Gaudzinski-Windheuser, Sabine

    2017-01-01

    Ancient protein sequences are increasingly used to elucidate the phylogenetic relationships between extinct and extant mammalian taxa. Here, we apply these recent developments to Middle Pleistocene bone specimens of the rhinoceros genus Stephanorhinus . No biomolecular sequence data is currently available for this genus, leaving phylogenetic hypotheses on its evolutionary relationships to extant and extinct rhinoceroses untested. Furthermore, recent phylogenies based on Rhinocerotidae (partial or complete) mitochondrial DNA sequences differ in the placement of the Sumatran rhinoceros ( Dicerorhinus sumatrensis ). Therefore, studies utilising ancient protein sequences from Middle Pleistocene contexts have the potential to provide further insights into the phylogenetic relationships between extant and extinct species, including Stephanorhinus and Dicerorhinus . ZooMS screening (zooarchaeology by mass spectrometry) was performed on several Late and Middle Pleistocene specimens from the genus Stephanorhinus , subsequently followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to obtain ancient protein sequences from a Middle Pleistocene Stephanorhinus specimen. We performed parallel analysis on a Late Pleistocene woolly rhinoceros specimen and extant species of rhinoceroses, resulting in the availability of protein sequence data for five extant species and two extinct genera. Phylogenetic analysis additionally included all extant Perissodactyla genera ( Equus , Tapirus ), and was conducted using Bayesian (MrBayes) and maximum-likelihood (RAxML) methods. Various ancient proteins were identified in both the Middle and Late Pleistocene rhinoceros samples. Protein degradation and proteome complexity are consistent with an endogenous origin of the identified proteins. Phylogenetic analysis of informative proteins resolved the Perissodactyla phylogeny in agreement with previous studies in regards to the placement of the families Equidae, Tapiridae, and

  16. Loess deposition and Paleolithic human activity in late Pleistocene in North China

    Science.gov (United States)

    Zhang, D.

    2013-12-01

    Loess is one of the best geological records in the world for reconstruction of paleoenvironment. Loess deposited widely in North China in Quaternary, composing the famous Chinese Loess Plateau where loess sections could be as thick as 200 m. In these thick loess profiles, various archaeological remains including human fossils are found across the Chinese Loess Plateau, which indicates the aeolian loess deposition provides a good preservation environment for archaeological remains or the environment when loess is deposited in North China is favorable for human subsistence. Therefore, well developed loess studies using conventional methods such as grain size, magnetism, carbonate contents, TOC and biological or chemical methods like pollen, phytolith, stable isotopes, could provide important information for archaeologists about site formation process, human subsistence environment and human adaptation behaviors. This study focuses on late Pleistocene environment change and human adaptation in Chinese Western Loess Plateau. Over fifty Paleolithic sites were found buried in loess sections in two small rive catchments about 400 km2 in Chinese Western Loess Plateau in this study. Based on the well loess study in this region, the ages of most of the sites could be easily assumed in the field, which were usually confirmed by later radiocarbon or OSL dating results. Paleoenvironment of human subsistence is reconstructed using pollen, grain size, magnetism studies on the loess profiles producing archaeological remains. The chronological framework built with absolute dating results and loess-paleosol sequence comparison shows that humans first appear in the study area during warm and humid MIS5, may have abandoned the area in cold MIS4, reappeared in cool but humid MIS3 and continued thereafter, even extremely cold and dry LGM. A comprehensive study of 3727 pieces of stone artifacts shows that small-flake-tool industry is dominant through most of the late Pleistocene and

  17. El registro más completo de un Hoplophorini (Xenarthra: Glyptodontidae para los Pisos/Edades Chapadmalalense-Marplatense (Plioceno tardío-Pleistoceno temprano The most complete record of a Hoplophorini (Xenarthra: Glyptodontidae for the Chapadmalalan-Marplatan Stages (Late Pliocene-Early Pleistocene

    Directory of Open Access Journals (Sweden)

    Alfredo E Zurita

    2011-06-01

    by Paraglyptodon chapadmalensis (Ameghino in Rovereto, a fossil guide of the Upper Chapadmalalan Stage, and the Plohophorini Plohophorus figuratus Ameghino. On the other hand, the "Hoplophorinae" Hoplophorini are glyptodonts that have its first records during the Huayquerian (late Miocene and "Araucanian" Stages (late Miocene-early Pliocene, but they are almost absents during the Chapadmalalan-Marplatan Stages (Pliocene-early Pleistocene. Later, the Hoplophorini (Neosclerocalyptus Paula Couto are, together with Glyptodon Owen, the most common South American Pleistocene Glyptodontidae. In this contribution we report the first record of a Chapadmalalan Hoplophorini, assigned to the genus Eosclerocalyptus C. Ameghino (Eosclerocalyptus cf. E. lineatus, coming from the Mar del Plata locality, Buenos Aires province (Argentina. This new material, represented by a complete dorsal carapace, was exhumed from the upper section of the Chapadmalalan Formation. From a morphological perspective, this dorsal carapace shows an intermediate size between E. tapinocephalus Cabrera, E. proximus (Moreno & Mercerat and Neosclerocalyptus Paula Couto. Together with cf. Paraglyptodon chapadmalensis and Plohophorus figuratus Ameghino those records represents the most entire Pliocene Glyptodontidae known and, in addition, it partially complete the stratigraphical distribution of the Glyptodontidae Hoplophorini.

  18. Continuity or discontinuity in the European Early Pleistocene human settlement: the Atapuerca evidence

    Science.gov (United States)

    Bermúdez de Castro, José María; Martinón-Torres, María; Blasco, Ruth; Rosell, Jordi; Carbonell, Eudald

    2013-09-01

    The nature, timing, pattern, favourable circumstances and impediments of the human occupation of the European continent during the Early Pleistocene are hot topics in Quaternary studies. In particular, the problem of the (dis) continuity of the settlement of Europe in this period is an important matter of discussion, which has been approached in the last decade from different points of view. The Gran Dolina (TD) and Sima del Elefante (TE) cave sites in the Sierra de Atapuerca, (Spain) include large and quasi-continuous stratigraphic sequences that stretch back from at least 1.2 million years ago (Ma) to the Matuyama/Brunhes boundary. The archaeological and paleontological record from these sites can help to test different hypotheses about the character of the human settlement in this region and period. Furthermore, the TD6 level has yielded a large collection of human fossil remains attributed to Homo antecessor. According to different geochronological methods, as well as to paleomagnetic and biostratigraphical analyses, these hominins belong to an age range of 0.96-0.80 Ma. Unfortunately, the finding in 2007 of some human fossil remains in the TE9 level, dated to about 1.22 Ma, was not enough to conclude whether H. antecessor had deep roots in the European Early Pleistocene. A set of derived features of H. antecessor shared with both the Neanderthal lineage and modern humans suggests that this species is related, and not far, from the most recent common ancestor (MRCA) of Homo neanderthalensis and Homo sapiens. If we assume that there was a lineal biological relationship between the TE9 and TD6 hominins, we should reconsider many of the conclusions achieved in previous paleontological and genetic studies. In addition, we would be obliged to build a highly complicated paleogeographical scenario for the origin of the MRCA. Although continuity in the settlement of Europe during the entire late Early Pleistocene is not discarded (e.g. in refuge areas), it seems that

  19. Direct evidence for human reliance on rainforest resources in late Pleistocene Sri Lanka.

    Science.gov (United States)

    Roberts, Patrick; Perera, Nimal; Wedage, Oshan; Deraniyagala, Siran; Perera, Jude; Eregama, Saman; Gledhill, Andrew; Petraglia, Michael D; Lee-Thorp, Julia A

    2015-03-13

    Human occupation of tropical rainforest habitats is thought to be a mainly Holocene phenomenon. Although archaeological and paleoenvironmental data have hinted at pre-Holocene rainforest foraging, earlier human reliance on rainforest resources has not been shown directly. We applied stable carbon and oxygen isotope analysis to human and faunal tooth enamel from four late Pleistocene-to-Holocene archaeological sites in Sri Lanka. The results show that human foragers relied primarily on rainforest resources from at least ~20,000 years ago, with a distinct preference for semi-open rainforest and rain forest edges. Homo sapiens' relationship with the tropical rainforests of South Asia is therefore long-standing, a conclusion that indicates the time-depth of anthropogenic reliance and influence on these habitats. Copyright © 2015, American Association for the Advancement of Science.

  20. Testing the correlation of fragmented pollen records of the middle and late Pleistocene temperate stages

    DEFF Research Database (Denmark)

    Kuneš, Petr; Odgaard, Bent Vad

    Quaternary temperate stages have long been described based on changing pollen abundances of various tree taxa in lacustrine sediments. Later, attempts have been made to assign such biostratigraphic units to distinct marine isotope stages (MIS). Existing continuous chronosequences from Southern...... records depends on site-to-site correlations. This comparison has often been performed on a visual basis, lacking clearly defined protocols and statements of underlying assumptions. Here I test the correlation of well and poorly known pollen records of the middle- and late-Pleistocene temperate stages...... from Northern-Central Europe and evaluate the usefulness of several numerical techniques. TWINSPAN analysis identifies groups of temperate stages based on presence/absence of their indicative taxa and may be useful for distinguishing between older and younger interglacials. Site-to-site sequence...

  1. Late Pleistocene sedimentation: A case study of the central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Borole, D

    -Sea Research 1, Vol 40, No 4, pp 761-775, 1993 0967-0637/93 $6 00 + 0 00 Printed m Great Britain © 1993 Pergamon Press Lid Late Pleistocene sedimentation: a case study of the central Indian Ocean Basin D. V. BOROLE* (Recetved 26 August 1988, in revised... 26 + 0 11 4 10 + 0.20 1 30 + 0 10 5 03 20-25 1 10 + 0.07 3 60 + 0.14 1 08 ___ 0 09 5 3 30-35 1 51 + 0.10 3.28 + 0 34 1.10 + 0.15 5 3 65-70 1.08 + 0 05 3 20 + 0.23 0 97 + 0.09 4 38 80-85 0 81 + 0 05 1 80 + 0.12 0 63 + 0 06 4 37 Conanued 766 D V...

  2. The earliest settlers of Mesoamerica date back to the late Pleistocene.

    Directory of Open Access Journals (Sweden)

    Wolfgang Stinnesbeck

    Full Text Available Preceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining the terminus ante quem for the pelvis to 11311±370 y BP. However, the skeleton might be considerable older, probably as old as 13 ky BP as indicated by the speleothem stable isotope data. The Chan Hol individual confirms a late Pleistocene settling of Mesoamerica and represents one of the oldest human osteological remains in America.

  3. Bone accumulation by leopards in the Late Pleistocene in the Moncayo massif (Zaragoza, NE Spain.

    Directory of Open Access Journals (Sweden)

    Víctor Sauqué

    Full Text Available Eating habits of Panthera pardus are well known. When there are caves in its territory, prey accumulates inside them. This helps to prevent its kill from being stolen by other predators like hyenas. Although the leopard is an accumulator of bones in caves, few studies have been conducted on existing lairs. There are, however, examples of fossil vertebrate sites whose main collecting agent is the leopard. During the Late Pleistocene, the leopard was a common carnivore in European faunal associations. Here we present a new locality of Quaternary mammals with a scarce human presence, the cave of Los Rincones (province of Zaragoza, Spain; we show the leopard to be the main accumulator of the bones in the cave, while there are no interactions between humans and leopards. For this purpose, a taphonomic analysis is performed on different bone-layers of the cave.

  4. Late Pleistocene lithostratigraphy and sequences in the southwestern Mesopotamia (Argentina): Evidences of the last interglacial stage

    Science.gov (United States)

    Ernesto, Brunetto; Soledad, Ferrero Brenda; Ignacio, Noriega Jorge

    2015-03-01

    The aim of this paper is to show the stratigraphic record of the Late Pleistocene corresponding to the distal region of the Paraná River basin. It displays sedimentological, paleontological and geochronological evidences that characterise the last interglacial-glacial cycle. In particular, strong environmental records are shown for the Last Interglacial Stage (LIS). Salto Ander Egg Formation (SAEF) is defined as a new lithostratigraphic unit representative of the Late Pleistocene in southwestern Mesopotamia. This unit is formed of complex fluvial deposits, which contains a heterogeneous collection of sub-environments, of ages ranging from 120 to 60 ky BP. The clast-supported gravel facies containing sparse boulders indicate high flow during a humid climate. The large and middle-scale architectures of fluvial sedimentary bodies evidence the relationship between the sediment accommodation and the sea level oscillations. Three sub-sequences identified in the succession suggest a transgressive trend during the MIS5e, a highstand stage in MIS5c, and a minor transgressive cycle during MIS3. A Brazilian faunal association collected at the bottom of the sequence and sedimentological interpretations display wet and warm climatic conditions, typical of tropical or subtropical environments. Such environmental conditions are characteristic of the maximum of the last interglacial stage (MIS5e) and show a signal stronger than the signal of the current interglacial stage. All these data show a direct correlation between the increases of paleodischarges and the elevation of the sea level. The whole sequence is completed with transitional swampy deposits, accumulated probably during the MIS3/MIS2 transition, and the typical loess of the Tezanos Pinto Formation, mantled during the Last Maximum Glacial.

  5. Shoreline deposits and diagenesis resulting from two Late Pleistocene highstands near +5 and +6 metres, Durban, South Africa

    Science.gov (United States)

    Cooper, J.A.G.; Flores, R.M.

    1991-01-01

    In exposures of Pleistocene rocks on the east coast of South Africa, eight sedimentary facies were distinguished on the basis of petrology, grain size, internal structures and field relationships. These are interpreted as deposits of surf zone, breaker zone, swash zone, backbeach, boulder beach and dune environments. Three phases of deposition and diagenesis are recognized. As a result of the stabilising effect of pre-existing coastal facies, the deposits from successive sea level stands are stacked vertically in a narrow coast-normal strip. Early cementation prevented erosion of the deposits during subsequent transgressions. Deposition of subsequent facies took place on an existing coastal dune (Facies 1). A terrace was cut into this dune at a sea level 4.5 to 5 m above present. At this sea level, clastic shoreline sediments were deposited which make up the main sedimentary sequence exposed (Facies 2-7). The steep swash zone, coarse grain size, and comparison with modern conditions in the study area indicate clastic deposition on a high-energy, wave-dominated, microtidal coastline. Vertical stacking of progressively shallower water facies indicates progradation associated with slightly regressive conditions, prior to stranding of the succession above sea level. During a subsequent transgression to 5.5 or 6 m above present sea level, a second terrace was cut across the existing facies, which by then were partly lithified. A boulder beach (Facies 8) deposited on this terrace is indicative of high wave energy and a rocky coastline, formed by existing cemented coastal facies. Comparison with dated deposits from other parts of the South African coast suggest a Late Pleistocene age for Facies 2-8. Deposition was terminated by subsequent regression and continuing low sea levels during the remainder of the Pleistocene. Cementation of the facies took place almost entirely by carbonate precipitation. The presence of isopachous fibrous cements suggests early cementation of

  6. Trophic interactions between larger crocodylians and giant tortoises on Aldabra Atoll, Western Indian Ocean, during the Late Pleistocene.

    Science.gov (United States)

    Scheyer, Torsten M; Delfino, Massimo; Klein, Nicole; Bunbury, Nancy; Fleischer-Dogley, Frauke; Hansen, Dennis M

    2018-01-01

    Today, the UNESCO World Heritage Site of Aldabra Atoll is home to about 100 000 giant tortoises, Aldabrachelys gigantea , whose fossil record goes back to the Late Pleistocene. New Late Pleistocene fossils (age ca . 90-125 000 years) from the atoll revealed some appendicular bones and numerous shell fragments of giant tortoises and cranial and postcranial elements of crocodylians. Several tortoise bones show circular holes, pits and scratch marks that are interpreted as bite marks of crocodylians. The presence of a Late Pleistocene crocodylian species, Aldabrachampsus dilophus , has been known for some time, but the recently found crocodylian remains presented herein are distinctly larger than those previously described. This indicates the presence of at least some larger crocodylians, either of the same or of a different species, on the atoll. These larger crocodylians, likely the apex predators in the Aldabra ecosystem at the time, were well capable of inflicting damage on even very large giant tortoises. We thus propose an extinct predator-prey interaction between crocodylians and giant tortoises during the Late Pleistocene, when both groups were living sympatrically on Aldabra, and we discuss scenarios for the crocodylians directly attacking the tortoises or scavenging on recently deceased animals.

  7. New evidences on the presence of Stegomastodon platensis Ameghino, 1888, Proboscidea: Gomphotheriidae, in the Late Pleistocene of Central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Labarca, R.; Alberdi, M.T.; Prado, J.L.; Mansilla, P.; Mourgues, F.A.

    2016-07-01

    This paper contextualizes, describes and taxonomically assigned cranial and dental Gomphotheriidae materials from the El Trebal 1, late Pleistocene form central Chile. Starting from metric and morphological variables fossils are included in Stegomastodon platensis. Taxonomic implications of this finding as well as some regional paleoenvironmental history are discussed. (Author)

  8. A cave response to environmental changes in the Late Pleistocene: a study of Budimirica Cave sediments, Macedonia

    Czech Academy of Sciences Publication Activity Database

    Temovski, M.; Pruner, Petr; Hercman, H.; Bosák, Pavel

    2016-01-01

    Roč. 69, č. 3 (2016), s. 307-316 ISSN 1330-030X Institutional support: RVO:67985831 Keywords : cave sediments * palaeoenvironmental changes * Late Pleistocene * Budimirica Cave * Macedonia Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.595, year: 2016 http://www. geologia -croatica.hr/ojs/index.php/GC

  9. Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada

    Science.gov (United States)

    Longstaffe, Fred J.; Zazula, Grant

    2018-01-01

    A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0–1 ‰) in δ13C of modern Yukon grasses. A major change (~2–10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time. PMID:29447202

  10. The late Pleistocene environment of the Eastern West Beringia based on the principal section at the Main River, Chukotka

    DEFF Research Database (Denmark)

    Kuzmina, Svetlana A.; Sher, Andrei V.; Edwards, Mary E.

    2011-01-01

    Chukotka is a key region for understanding both Quaternary environmental history and transcontinental migrations of flora and fauna during the Pleistocene as it lies at the far eastern edge of Asia bordering the Bering Sea. The now submerged land bridge is the least understood region of Beringia...... yet the most critical to understanding migrations between the Old and New Worlds. The insect fauna of the Main River Ledovy Obryv (Ice Bluff) section, which is late Pleistocene in age (MIS 3-2), is markedly different from coeval faunas of areas further to the west, as it is characterized by very few...

  11. Compilation of information on the climate and evaluation of the hydrochemical and isotopic composition during Late Pleistocene and Holocene

    International Nuclear Information System (INIS)

    Andersson, Cecilia

    1998-01-01

    This report summarises and evaluates some of the existing information on the Late Pleistocene and Holocene climates, i.e. the last 130 000 years. An estimation of the conditions at the Aespoe island (southeast Sweden) has also been made during this time span. The knowledge about Late Pleistocene (Eemian Interglacial and Weichselian glacial) is not yet fully understood. There are still a lot of assumptions concerning this period and more information is needed to be able to establish the climatic conditions. This is not the case for the Weichselian deglaciation and the present interglacial, Holocene, for which the environmental conditions are quite certain. It has been concluded, however, that the Eemian climatic development probably was similar to the Holocene but perhaps somewhat warmer and more humid. The Eemian Baltic Sea level was probably also higher than the present Baltic Sea level and there was a connection between it and the White Sea in the northeast. Aespoe was probably situated below sea level during the greater part of Eemian. Not much is known about the last glacial period, the Weichselian glaciation, until the final deglaciation. The ice sheet during Early Weichselian was probably mostly concentrated to the Scandinavian mountain area and in northern Scandinavia. At least two intervals with higher temperatures have been recorded, the Broerup and Odderade interstadials. The Middle Weichselian substage is characterised by fluctuations, melting and re-advances. Aespoe was probably not glaciated until the middle or latter part of Middle Weichselian. The maximum extension of the Weichselian ice sheet occurred in Late Weichselian, around 20 to 18 ka BP, which was succeeded by the final deglaciation. The retreat of the Weichselian ice sheet is described by for example end moraines and glacial varved clay. The Aespoe area was glaciated until 12 500 BP. Huge quantities of glacial meltwater was released into the Baltic basin as the ice receded. Due to different

  12. Compilation of information on the climate and evaluation of the hydrochemical and isotopic composition during Late Pleistocene and Holocene

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Cecilia [Intera KB (Sweden)

    1998-01-01

    This report summarises and evaluates some of the existing information on the Late Pleistocene and Holocene climates, i.e. the last 130 000 years. An estimation of the conditions at the Aespoe island (southeast Sweden) has also been made during this time span. The knowledge about Late Pleistocene (Eemian Interglacial and Weichselian glacial) is not yet fully understood. There are still a lot of assumptions concerning this period and more information is needed to be able to establish the climatic conditions. This is not the case for the Weichselian deglaciation and the present interglacial, Holocene, for which the environmental conditions are quite certain. It has been concluded, however, that the Eemian climatic development probably was similar to the Holocene but perhaps somewhat warmer and more humid. The Eemian Baltic Sea level was probably also higher than the present Baltic Sea level and there was a connection between it and the White Sea in the northeast. Aespoe was probably situated below sea level during the greater part of Eemian. Not much is known about the last glacial period, the Weichselian glaciation, until the final deglaciation. The ice sheet during Early Weichselian was probably mostly concentrated to the Scandinavian mountain area and in northern Scandinavia. At least two intervals with higher temperatures have been recorded, the Broerup and Odderade interstadials. The Middle Weichselian substage is characterised by fluctuations, melting and re-advances. Aespoe was probably not glaciated until the middle or latter part of Middle Weichselian. The maximum extension of the Weichselian ice sheet occurred in Late Weichselian, around 20 to 18 ka BP, which was succeeded by the final deglaciation. The retreat of the Weichselian ice sheet is described by for example end moraines and glacial varved clay. The Aespoe area was glaciated until 12 500 BP. Huge quantities of glacial meltwater was released into the Baltic basin as the ice receded. Due to different

  13. Late Pleistocene songbirds of Liang Bua (Flores, Indonesia); the first fossil passerine fauna described from Wallacea

    Science.gov (United States)

    Sutikna, Thomas; Saptomo, Wahyu; Jatmiko; Wasisto, Sri; Tocheri, Matthew W.; Mayr, Gerald

    2017-01-01

    Background Passerines (Aves: Passeriformes) dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene–Holocene deposits (∼190 ka to present day). Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence. Methods We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines. Results At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos), the Australasian Bushlark (Mirafra javanica), a friarbird (Philemon sp.), and the Pechora Pipit (Anthus cf. gustavi). Discussion These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres) and a grassbird (Megalurus sp.). Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp.), giant storks (Leptoptilos robustus), komodo dragons (Varanus komodoensis), and probably H. floresiensis as well. PMID:28828271

  14. Late Pleistocene songbirds of Liang Bua (Flores, Indonesia; the first fossil passerine fauna described from Wallacea

    Directory of Open Access Journals (Sweden)

    Hanneke J.M. Meijer

    2017-08-01

    Full Text Available Background Passerines (Aves: Passeriformes dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene–Holocene deposits (∼190 ka to present day. Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence. Methods We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines. Results At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos, the Australasian Bushlark (Mirafra javanica, a friarbird (Philemon sp., and the Pechora Pipit (Anthus cf. gustavi. Discussion These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres and a grassbird (Megalurus sp.. Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp., giant storks (Leptoptilos robustus, komodo dragons (Varanus komodoensis, and probably H. floresiensis as well.

  15. Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes, central Mexico

    Science.gov (United States)

    Macias, J.L.; Garcia, P.A.; Arce, J.L.; Siebe, C.; Espindola, J.M.; Komorowski, J.C.; Scott, K.

    1997-01-01

    This field guide describes a five day trip to examine deposits of Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes in central Mexico. We will discuss the stratigraphy, petrology, and sedimentological characteristics of these deposits which provide insights into the eruptive history, type of volcanic activity, and transport and emplacement mechanisms of pyroclastic materials. These parameters will allow us to discuss the kinds of hazards and the risk that they pose to populations around these volcanoes. The area to be visited is tectonically complex thus we will also discuss the location of the volcanoes with respect to the tectonic environment. The first four days of the field trip will be dedicated to Nevado de Toluca Volcano (19 degrees 09'N; 99 degrees 45'W) located at 23 km. southwest of the City of Toluca, and is the fourth highest peak in the country, reaching an elevation of 4,680 meters above sea level (m.a.s.l.). Nevado de Toluca is an andesitic-dacitic stratovolcano, composed of a central vent excavated upon the remains of older craters destroyed by former events. Bloomfield and Valastro, (1974, 1977) concluded that the last cycle of activity occurred nearly equal 11,600 yr. ago. For this reason Nevado de Toluca has been considered an extinct volcano. Our studies, however, indicate that Nevado de Toluca has had at least two episodes of cone destruction by sector collapse as well as several explosive episodes including plinian eruptions and dome-destruction events. These eruptions occurred during the Pleistocene but a very young eruption characterized by surge and ash flows occurred ca. 3,300 yr. BP. This new knowledge of the volcano's eruptive history makes the evaluation of its present state of activity and the geological hazards necessary. This is important because the area is densely populated and large cities such as Toluca and Mexico are located in its proximity.

  16. Late Pleistocene flank collapse of Zempoala volcano (Central Mexico) and the role of fault reactivation

    Science.gov (United States)

    Arce, José Luis; Macías, Rodolfo; García Palomo, Armando; Capra, Lucia; Macías, José Luis; Layer, Paul; Rueda, Hernando

    2008-11-01

    Zempoala is an extinct Pleistocene (˜ 0.7-0.8 Ma) stratovolcano that together with La Corona volcano (˜ 0.9 Ma) forms the southern end of the Sierra de las Cruces volcanic range, Central Mexico. The volcano consists of andesitic and dacitic lava flows and domes, as well as pyroclastic and epiclastic sequences, and has had a complex history with several flank collapses. One of these collapses occurred during the late Pleistocene on the S-SE flank of the volcano and produced the Zempoala debris avalanche deposit. This collapse could have been triggered by the reactivation of two normal fault systems (E-W and NE-SW), although magmatic activity cannot be absolutely excluded. The debris avalanche traveled 60 km to the south, covers an area of 600 km 2 and has a total volume of 6 km 3, with a calculated Heim coefficient (H/L) of 0.03. Based on the textural characteristics of the deposit we recognized three zones: proximal, axial, and lateral distal zone. The proximal zone consists of debris avalanche blocks that develop a hummocky topography; the axial zone corresponds with the main debris avalanche deposit made of large clasts set in a sandy matrix, which transformed to a debris flow in the lateral distal portion. The deposit is heterolithologic in composition, with dacitic and andesitic fragments from the old edifice that decrease in volume as bulking of exotic clasts from the substratum increase. Several cities (Cuernavaca, Jojutla de Juárez, Alpuyeca) with associated industrial, agricultural, and tourism activities have been built on the deposit, which pose in evidence the possible impact in case of a new event with such characteristics, since the area is still tectonically active.

  17. Presencia de Antifer ultra Ameghino (=Antifer niemeyeri Casamiquela (Artiodactyla, Cervidae en el Pleistoceno tardío-Holoceno temprano de Chile central (30-35°S Presence of Antifer ultra Ameghino (=Antifer niemeyeri Casamiquela in the late Pleistocene-early Holocene of Central Chile (30-35°S

    Directory of Open Access Journals (Sweden)

    Rafael Labarca E

    2011-01-01

    Full Text Available El presente trabajo discute el estatus taxonómico de la especie Antifer niemeyeri Casamiquela, 1984, definida a partir de astas completas procedentes de la laguna Taguatagua y la quebrada de Quereo (Pleistoceno tardío-Holoceno temprano, en Chile central (30-35°S. Se concluye, a partir de un estudio morfológico y morfométrico detallado, que Antifer niemeyeri debe ser considerado sinónimo de Antifer ultra Ameghino, 1889 dados los caracteres anatómicos compartidos con esta especie. Los resultados amplían la distribución geográfica del taxón, que previamente se registraba en Argentina, Uruguay y sur de Brasil, y confirman su biocrón para el Pleistoceno tardío-Holoceno temprano (edad Lu-janense, aun cuando las fechas radiocarbónicas de Chile central (ca. 9.900 años 14C AP corresponden a las más tardías para la especie. A la luz de la evidencia paleoclimática disponible, se vincula A ultra durante el Pleistoceno de Chile central a ambientes cálidos y abiertos. Considerando estos requerimientos, se discute su posible vía de ingreso al actual territorio chileno a través de corredores ubicados hacia el sur del macizo andino, y su coexistencia con Hippocamelus bisulcus Molina, 1782. De acuerdo a la información estratigráfica y paleoambiental, se postula que ambas especies habrían sido alopátridas, por lo menos en el área de estudio.This paper discusses the taxonomic status of Antifer niemeyeri Casamiquela, 1984, defined from complete antlers from Taguatagua lake and Quereo canyon, both located in central Chile (30-35°S. From a detailed morphological and moiphometrical study, it is concluded that Antifer niemeyeri should be considered synonymous with Antifer ultra Ameghino, 1889, due to the anatomical characters shared between both forms. These results expand the geographical distribution of this taxa previously recorded in Argentina, Uruguay and southern Brazil, confirming their late Pleistocene-early Holocene biochron, in spite

  18. Seasonality of the late Pleistocene Dawson tephra and exceptional preservation of a buried riparian surface in central Yukon Territory, Canada

    Science.gov (United States)

    Froese, Duane G.; Zazula, Grant D.; Reyes, Alberto V.

    2006-07-01

    The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25,300C yr BP, near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early spring. Multiple, fining-upward tephra-rich ice beds are interpreted as remnants of surface icings, which presently are common in the region during spring. A buried in situ riparian meadow, preserved below the icing and tephra, consists of abundant tufted hair grass ( Deschampsia caespitosa), with interspersed horsetails ( Equisetum cf. palustre) and mosses. Detrital plant remains and preserved in situ grass inflorescences entombed in the icing had expelled their fruits, consistent with a late season surface when the icing was active. The extraordinary thickness of Dawson tephra in central Yukon likely reflects reworking of a winter-deposited tephra by snow melt in the spring following the eruption, indicating that the primary thickness may be overestimated at valley-bottom sites. Winter deposition of the tephra may have, in part, minimized the terrestrial ecological impacts of the eruption on zonal "steppe-tundra" vegetation through the retransportation of tephra from hillslopes to the riparian areas, where the tephra became incorporated into local fluvial systems.

  19. Reconstructing the climate states of the Late Pleistocene with the MIROC climate model

    Science.gov (United States)

    Chan, Wing-Le; Abe-Ouchi, Ayako; O'ishi, Ryouta; Takahashi, Kunio

    2014-05-01

    The Late Pleistocene was a period which lasted from the Eemian interglacial period to the start of the warm Holocene and was characterized mostly by widespread glacial ice. It was also a period which saw modern humans spread throughout the world and other species of the same genus, like the Neanderthals, become extinct. Various hypotheses have been put forward to explain the extinction of Neanderthals, about 30,000 years ago. Among these is one which involves changes in past climate and the inability of Neanderthals to adapt to such changes. The last traces of Neanderthals coincide with the end of Marine Isotope Stage 3 (MIS3) which was marked by large fluctuations in temperature and so-called Heinrich events, as suggested by geochemical records from ice cores. It is thought that melting sea ice or icebergs originating from the Laurentide ice sheet led to a large discharge of freshwater into the North Atlantic Ocean during the Heinrich events and severely weakened the Atlantic meridional overturning circulation, with important environmental ramifications across parts of Europe such as sharp decreases in temperature and reduction in forest cover. In order to assess the effects of past climate change on past hominin migration and on the extinction of certain species, it is first important to have a good understanding of the past climate itself. In this study, we have used three variants of MIROC (The Model for Interdisciplinary Research on Climate), a global climate model, for a time slice experiment within the Late Pleistocene: two mid-resolution models (an atmosphere model and a coupled atmosphere-ocean model) and a high-resolution atmosphere model. To obtain a fuller picture, we also look at a cool stadial state as obtained from a 'freshwater hosing' coupled-model experiment, designed to mimic the effects of freshwater discharge in the North Atlantic. We next use the sea surface temperature response from this experiment to drive the atmosphere models. We discuss

  20. Stratigraphic Reconstruction of a Late Pleistocene Cypress Forest Discovered on the Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Gonzalez Rodriguez, S. M.; Bentley, S. J.; Obelcz, J.; Truong, J. T.; DeLong, K. L.; Xu, K.; Harley, G. L.; Reese, C. A.; Caporaso, A.; Shen, Z.

    2017-12-01

    A previously buried bald cypress forest (Taxodium distichum) was discovered on the continental shelf, offshore of Orange Beach, Alabama, USA, in 20 m water depth. The forest was possibly exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position in a trough located in the northern Gulf of Mexico continental shelf seafloor. We are investigating the local stratigraphy, paleo-landscape, and mode of forest preservation of this unique site. In August 2015 and July 2016, submersible vibracores (18 in total) were collected. Core analysis included: bulk density and imaging via Geotek multi sensor core logger, sediment grain size, structure, and organic content via loss-on-ignition. Selected samples have been dated using 14C and optically stimulated luminescence (OSL) methods. Multibeam and CHIRP subbottom bathymetry provide context for litho- and chrono-stratigraphy of the site. Integration of core lithostratigraphy and modern shelf bathymetry reveal Holocene transgressive sands blanketing diverse sedimentary facies that are truncated by the late Pleistocene-early Holocene ravinement. Deposits below the ravinement surface include interbedded sand and mud (exact age unknown, but possibly pertaining to a shallow marine environment), overlying a floodplain/swamp facies of woody debris, peat, and mud (provisionally dated by 14C to 41-45 ka). These units grade laterally into paleosols that appear to be 10-15 ka older, based on recently obtained preliminary OSL dates. Occurrence of paleosols and swamp deposits of broadly similar age and elevation suggests that the ancient landscape possessed topographic relief that allowed wetland and upland habitats to develop in close proximity. These new OSL dates enhance our initial hypothesis that floodplain aggradation in the area was a key factor that might have allowed forest preservation. The timing of temporary sea level rises (SLR) ca. 40 and 60 ka. with our 14C and preliminary OSL dates, suggests that floodplain

  1. The Pliocene initiation and Early Pleistocene volcanic disruption of the palaeo-Gediz fluvial system, Western Turkey

    NARCIS (Netherlands)

    Maddy, D.; Demir, T.; Bridgland, D.R.; Veldkamp, A.; Stemerdink, C.; Schriek, van der T.; Schreve, D.

    2007-01-01

    In this paper, we report our latest observations concerning a Pliocene and Early Pleistocene record from Western Turkey. The sedimentary sequence described comprises the fluvial deposits of an Early Pleistocene palaeo-Gediz river system and its tributaries prior to the onset of volcanism around Kula

  2. Reconstruction of a semi-arid late Pleistocene paleocatena from the Lake Victoria region, Kenya

    Science.gov (United States)

    Beverly, Emily J.; Driese, Steven G.; Peppe, Daniel J.; Arellano, L. Nicole; Blegen, Nick; Faith, J. Tyler; Tryon, Christian A.

    2015-11-01

    The effect of changing environment on the evolution of Homo sapiens is heavily debated, but few data are available from equatorial Africa prior to the last glacial maximum. The Karungu deposits on the northeast coast of Lake Victoria are ideal for paleoenvironmental reconstructions and are best studied at the Kisaaka site near Karunga in Kenya (94 to > 33 ka) where paleosols, fluvial deposits, tufa, and volcaniclastic deposits (tuffs) are exposed over a 2 km transect. Three well-exposed and laterally continuous paleosols with intercalated tuffs allow for reconstruction of a succession of paleocatenas. The oldest paleosol is a smectitic paleo-Vertisol with saline and sodic properties. Higher in the section, the paleosols are tuffaceous paleo-Inceptisols with Alfisol-like soil characteristics (illuviated clay). Mean annual precipitation (MAP) proxies indicate little change through time, with an average of 764 ± 108 mm yr- 1 for Vertisols (CALMAG) and 813 ± 182 to 963 ± 182 mm yr- 1 for all paleosols (CIA-K). Field observations and MAP proxies suggest that Karungu was significantly drier than today, consistent with the associated faunal assemblage, and likely resulted in a significantly smaller Lake Victoria during the late Pleistocene. Rainfall reduction and associated grassland expansion may have facilitated human and faunal dispersals across equatorial East Africa.

  3. The timing of Late Pleistocene glaciation at Mount Wilhelm, Papua New Guinea

    Science.gov (United States)

    Mills, Stephanie; Barrows, Timothy; Hope, Geoff; Pillans, Brad; Fifield, Keith

    2016-04-01

    The highlands of New Guinea were the most extensively glaciated area in the Asian tropical region during the Late Pleistocene. Evidence for glaciation is widespread on most of the mountain peaks above ~3500 m. Glacial landforms include both valley and ice cap forms, but the timing of glaciation remains constrained to only a few local areas. This paper focuses on Mount Wilhelm, which is situated in the central southern region of Papua New Guinea at 5.78°S and is the highest peak (4510 m a.s.l.) We focus on a south easterly valley (Pindaunde Valley) emanating from the peak, where large moraines indicate the maximum ice extent of a valley glacier ~5 km long. Within this extensive moraine complex, recessional moraines document the retreat of the glacier towards the summit region. In order to determine the timing of deglaciation, we collected samples for surface exposure dating using 36Cl and 10Be from diorite boulders positioned on moraine crests. The ages indicate that maximum ice extent was attained during the last glacial maximum (LGM) and that ice remained near its maximum extent until after 15 ka but persisted at higher elevations almost until the Holocene. These results are similar to those described from Mt Giluwe to the northwest of Mount Wilhelm, where an ice cap reached its maximum extent at the LGM and remained there for around 3-4,000 years. This indicates that full glacial conditions were only brief in this region of the tropics.

  4. Late Pleistocene paleohydrology near the boundary of the Sonoran and Chihuahuan Deserts, southeastern Arizona, USA

    Science.gov (United States)

    Pigati, Jeffery S.; Bright, Jordon E.; Shanahan, Timothy M.; Mahan, Shannon

    2009-01-01

    Ground-water discharge (GWD) deposits form in arid environments as water tables rise and approach or breach the ground surface during periods of enhanced effective precipitation. Where preserved, these deposits contain information on the timing and elevation of past ground-water fluctuations. Here we report on the investigation of a series of GWD deposits that are exposed in discontinuous outcrops along a ???150-km stretch of the San Pedro Valley in southeastern Arizona, near the boundary of the Sonoran and Chihuahuan Deserts. Chronologic, isotopic, geochemical, faunal assemblage (ostracodes and gastropods), and sedimentological evidence collectively suggest that the elevation of the regional water table in the valley rose in response to a change in climate ???50 ka ago and remained relatively high for the next ???35 ka before falling during the B??lling-Aller??d warm period, rebounding briefly during the Younger Dryas cold event, and falling again at the onset of the Holocene. The timing of these hydrologic changes coincides closely with variations in ??18O values of calcite from a nearby speleothem to the west and changes in lake levels at pluvial Lake Cochise to the east. Thus, in southeastern Arizona, the assumption that changes in climate are reflected in all aspects of the hydrologic cycle of a region simultaneously is validated. The timing of these changes also broadly coincides with variations in the GISP2 ??18O record, which supports the hypothesis that atmospheric teleconnections existed between the North Atlantic and the deserts of the American Southwest during the late Pleistocene.

  5. Optically stimulated luminescence age controls on late Pleistocene and Holocene coastal lithosomes, North Carolina, USA

    Science.gov (United States)

    Mallinson, D.; Burdette, K.; Mahan, S.; Brook, G.

    2008-01-01

    Luminescence ages from a variety of coastal features on the North Carolina Coastal Plain provide age control for shoreline formation and relative sea-level position during the late Pleistocene. A series of paleoshoreline ridges, dating to Marine Isotope Stage (MIS) 5a and MIS 3 have been defined. The Kitty Hawk beach ridges, on the modern Outer Banks, yield ages of 3 to 2??ka. Oxygen-isotope data are used to place these deposits in the context of global climate and sea-level change. The occurrence of MIS 5a and MIS 3 shorelines suggests that glacio-isostatic adjustment (GIA) of the study area is large (ca. 22 to 26??m), as suggested and modeled by other workers, and/or MIS 3 sea level was briefly higher than suggested by some coral reef studies. Correcting the shoreline elevations for GIA brings their elevation in line with other sea-level indicators. The age of the Kitty Hawk beach ridges places the Holocene shoreline well west of its present location at ca. 3 to 2??ka. The age of shoreline progradation is consistent with the ages of other beach ridge complexes in the southeast USA, suggesting some regionally contemporaneous forcing mechanism. ?? 2007 University of Washington.

  6. Late to middle Pleistocene Arctic glacial history implied from a sedimentary record from the Northwind Ridge

    Science.gov (United States)

    Liu, Y.; Dong, L.; Shi, X.; Zhu, A.

    2017-12-01

    Abstract: Sediment core ARC6-C21 collected from the Northwind Ridge, western Arctic Ocean, covers the late to middle Quaternary (Marine Isotope Stages (MIS) 1-11), as estimated by correlation to earlier proposed Arctic Ocean stratigraphies and AMS14C dating of the youngest sediments. Detailed examination of the elemental composition of sediment along with grain size in core ARC6-C21 provides important new information about sedimentary environments and provenance. We use increased contents of coarse debris as an indicator of glacier collapse events at the margins of the western Arctic Ocean, and identify the provenance of these events from geochemical composition. Notably, peaks of MgO and CaO, including large dropstones, presumably track the Laurentide Ice Sheet (LIS) discharge events to the Arctic Ocean. Major LIS inputs occurred during the stratigraphic intervals estimated as MIS 3, intra-MIS 5 and 7 events, MIS 8, and MIS 10. Inputs from the East Siberian Ice Sheet (ESIS) and/or Eurasia Ice Sheet (EIS)are inferred from peaks of SiO2, K2O and Na2O associated with coarse sediment. Major ESIS and/or EIS sedimentary events occurred in the intervals estimated as MIS 2, MIS 4, MIS 6, MIS 8 and MIS 10. Keywords: Sediment core, Pleistocene, western Arctic Ocean, geochemistry, grain size, sediment provenance, glaciations

  7. Paleoecological and climatic implications of stable isotope results from late Pleistocene bone collagen, Ziegeleigrube Coenen, Germany

    Science.gov (United States)

    Wißing, Christoph; Matzerath, Simon; Turner, Elaine; Bocherens, Hervé

    2015-07-01

    Climatic and ecological conditions during Marine Oxygen Isotope Stage (MIS) 3 are complex and the impact of cold spells on the ecosystems in Central Europe still needs to be investigated thoroughly. Ziegeleigrube Coenen (ZC) is a late Pleistocene MIS 3 locality in the Lower Rhine Embayment of Germany, radiocarbon-dated to > 34 14C ka BP. The site yielded a broad spectrum of mammal species. We investigated the carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope signatures of bone collagen, since these are valuable tools in characterizing ecological niches, environmental conditions and aspects of climate and mobility. By comparison with pre- and post-Last Glacial Maximum (LGM) sites in Central Europe we show that ZC belongs in a cold event of MIS 3 and was climatically more similar to post-LGM sites than to pre-LGM sites. However, the trophic structure resembled that of typical pre-LGM sites in Belgium. This cold event in MIS 3 changed the bottom of the foodweb, but do not seem to have had a direct impact on the occurrence of the mammalian species and their ecological distribution. Apparently the (mega-) faunal community could adapt also to harsher environmental conditions during MIS 3.

  8. Radiolarian Indices of Paleoproductivity Variation in the late Pleistocene Benguela Upwelling System, ODP Site 1084

    Science.gov (United States)

    Bittniok, B. B.; Lazarus, D. B.; Diester-Haass, L.; Billups, K.; Meyers, P.

    2006-12-01

    Changes in export productivity play a significant role in ocean carbon budgets and global climate change. Proxies for export productivity can be difficult to interpret: benthic foraminifera accumulation rates (BFAR) can be affected by carbonate dissolution in organic-carbon rich sediments; bulk opal can be affected by silica limitation of source waters. Recent work (Lazarus et al. 2006; Mar. Micropal.) has shown that a new index based on radiolarian faunal changes (WADE ratio) correlates well to total organic carbon (TOC) values from the same samples over the long term (latest Miocene-Recent) history of productivity in the Benguela Upwelling System (BUS). We present new data on variation in export productivity proxies (WADE, TOC, carbonate, radiolarian opal, BFAR) for the last glacial-interglacial cycle from ODP Site 1084, located just offshore from the main coastal upwelling cells of the BUS. Our age model, from mean Quaternary sedimentation rates (Leg 175 Scientific Results), is in accordance with cyclic variation in other climate sensitive parameters (carbonate and color reflectance). Although opal content and radiolarian preservation is only moderate in our samples, WADE values vary significantly and suggest higher productivity during the last glacial, in accordance with current interpretations of BUS history. Radiolarian opal accumulation is also higher during the last glacial, suggesting that silica limitation (opal paradox) conditions did not dominate over this time period. Similar results for bulk opal have been reported from late Quaternary piston cores from the more northerly Congo upwelling region (Schneider et al, 1997; Paleoc.). We conclude that WADE ratios are a useful proxy for late Pleistocene productivity in the BUS at glacial- interglacial time scales.

  9. Late Pleistocene deglaciation chronology in the NW of the Iberian Peninsula using cosmic-ray produced 21Ne in quartz

    International Nuclear Information System (INIS)

    Fernandez Mosquera, D.; Marti, K.; Romani, J.R. Vidal; Weigel, A.

    2000-01-01

    Late Pleistocene glaciations in the NW Iberian Peninsula over Serra de Queixa and Serra de Xures, all with granite substrata, were studied by mass spectrometry using cosmogenic 21 Ne. Rock cores were drilled in glacial polished surfaces and push-moraine boulders, and were analyzed to determine their integral exposure time to cosmic rays. First results, which are consistent with the relative geomorphologic model estimates, allow the identification of at least three different glacial stages, with the latest terminating about 15 ka BP

  10. Connection of the Late Paleolithic archaeological sites of the Chuya depression with geological evidence of existence of the Late Pleistocene ice-dammed lakes

    Science.gov (United States)

    Agatova, A. R.; Nepop, R. K.

    2017-07-01

    The complexity of the age dating of the Pleistocene ice-dammed paleolakes in the Altai Mountains is a reason why geologists consider the Early Paleolithic archaeological sites as an independent age marker for dating geological objects. However, in order to use these sites for paleogeographic reconstructions, their locations, the character of stratification, and the age of stone artifacts need to be comprehensively studied. We investigate 20 Late Paleolithic archaeological sites discovered in the Chuya depression of the Russian Altai (Altai Mountains) with the aim of their possible use for reconstructions of the period of development of the Kurai-Chuya glacio-limnosystem in the Late Neopleistocene. The results of our investigation show that it is improper to use the Paleolithic archaeological sites for the dating of the existence period and the draining time of ice-dammed lakes of the Chuya Depression in the modern period of their study owing to a lack of quantitative age estimates, a wide age range of possible existence of these sites, possible redeposition of the majority of artifacts, and their surface occurrence. It is established that all stratified sites where cultural layers are expected to be dated in the future lie above the uppermost and well-expressed paleolake level (2100 m a.s.l.). Accordingly, there are no grounds to determine the existence time of shallower paleolakes. Since the whole stone material collected below the level of 2100 m a.s.l. is represented by surface finds, it is problematic to use these artifacts for absolute geochronology. The Late Paleolithic Bigdon and Chechketerek sites are of great interest for paleogeographic reconstructions of ice-dammed lakes. The use of iceberg rafting products as cores is evidence that these sites appeared after the draining of a paleolake (2000 m a.s.l.). At this time, the location of these archaeological sites on the slope of the Chuya Depression allows one to assume the existence of a large lake as deep

  11. Late Pleistocene to Holocene environmental changes as recorded in the sulfur geochemistry of coastal plain sediments, southwestern Taiwan

    Science.gov (United States)

    Chen, Y.-G.; Liu, J.C.-L.; Shieh, Y.-N.; Liu, T.-K.

    2004-01-01

    A core, drilled at San-liao-wan in the southwestern coastal plain of Taiwan, has been analyzed for total sulfur contents, isotopic values, as well as ratios of pyritic sulfur to organic carbon. Our results demonstrate a close relationship between late Pleistocene sea-level change and the proxies generated in this study. The inorganic sulfur contents indicate that at our study site, the Holocene transgression started at ???11 ka and remained under seawater for thousands of years until the late Holocene, corresponding to a depth of 20 m in the study core. The uppermost 20 m of core shows relatively high total organic carbon (TOC) and ??34S of inorganic sulfur, suggesting a transitional environment such as muddy lagoon or marsh, before the site turned into a modern coastal plain. In the lower part of the core, at depths of 110-145 m (corresponding ages of ???12-30 ka), low sulfur contents are recorded, probably indicating fluvial sediments deposited during the oceanic isotope stage (OIS) 2, a sea-level lowstand. The lower part of the core, roughly within OIS 3, records at least two transgressions, although the transgressional signals may be somewhat obscured by subsequent weathering. The reworked origin of organic matter reported in previous studies is confirmed by our organic sulfur data; however, the marine organic source was periodically dominant. The modern high sulfate concentrations in pore water have no correlation to the other sulfur species in the sediments, probably indicating that the sulfate migrated into the site subsequent to early diagenesis. ?? 2003 Elsevier Ltd. All rights reserved.

  12. Late Pleistocene Megafaunal Extinction Consistent With YDB Impact Hypothesis at Younger Dryas Onset

    Science.gov (United States)

    Kennett, J. P.; Kennett, D. J.

    2008-12-01

    At least 35 mammal and 19 bird genera became extinct across North America near the end of the Pleistocene. Modern increases in stratigraphic and dating resolution suggest that this extinction occurred relatively rapidly near 12.9 ka (11 radiocarbon kyrs). Within the context of a long-standing debate about its cause, Firestone et al., (2007) proposed that this extinction resulted from an extraterrestrial (ET) impact over North America at 12.9 ka. This hypothesis predicts that the extinction of most of these animals should have occurred abruptly at 12.9 ka. To test this hypothesis, we have critically examined radiocarbon ages and the extinction stratigraphy of these taxa. From a large data pool, we selected only radiocarbon dates with low error margins with a preference for directly dated biological materials (e.g., bone, dung, etc.) and modern chemical purification techniques. A relatively small number of acceptable dates indicate that at least 16 animal genera and several other species became extinct close to 12.9 ka. These taxa include the most common animals of the late Pleistocene such as horses, camels, and mammoths. Also, the remains of extinct taxa are reportedly found up to, but not above, the base of a widely distributed carbon-rich layer called the black mat. This stratum forms an abrupt, major biostratigraphic boundary at the Younger Dryas onset (12.9 ka), which also contains multiple ET markers comprising the impact layer (the YDB). Surviving animal populations were abruptly reduced at the YDB (e.g., Bison), with major range restrictions and apparent evolutionary bottlenecks. The abruptness of this major extinction is inconsistent with the hypotheses of human overkill and climatic change. We argue that extinction ages older than 12.9 ka for many less common species result from the Signor-Lipps effect, but the impact hypothesis predicts that as new dates are acquired, they will approach ever closer to 12.9 ka. The megafaunal extinction is strongly

  13. The lithic industry of Sima del Elefante (Atapuerca, Burgos, Spain) in the context of Early and Middle Pleistocene technology in Europe.

    Science.gov (United States)

    de Lombera-Hermida, Arturo; Bargalló, Amèlia; Terradillos-Bernal, Marcos; Huguet, Rosa; Vallverdú, Josep; García-Antón, Maria-Dolores; Mosquera, Marina; Ollé, Andreu; Sala, Robert; Carbonell, Eudald; Rodríguez-Álvarez, Xosé-Pedro

    2015-05-01

    This paper presents the lithic assemblages documented at Sima del Elefante (TE) and their importance in the context of the Early and Middle Pleistocene human occupation of Europe. We also study changes in human behaviour within the context of the palaeoenvironmental evolution of the Sierra de Atapuerca. This site has characteristics that are of great value for the study of human evolution. The lower levels of TE (Units TE7-TE14) are an essential reference for understanding the early stages of the colonization of Europe. The TE9c level has provided stone tools (Mode 1), faunal remains, and human fossils dated to 1.22 Ma (millions of years ago). Moreover, this is one of the few European sites with a stratigraphic sequence that includes remains of human occupations predating the Jaramillo subchron (Early Pleistocene) and from the Late Middle Pleistocene (Units TE18-TE19). Despite this, the presence of archaeologically sterile units (TE15-17) prevents us from establishing a continuous relationship between the Early and Middle Pleistocene human settlements and, consequently, between their technological and behavioural differences. We can, however compare the technological and palaeoeconomic strategies adopted by different species of hominins during two key phases of the occupation of Europe. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Spatial prediction of the variability of early pleistocene subsurface sediments in the Netherlands part 2: geochemistry

    NARCIS (Netherlands)

    Huisman, D.J.; Weijers, J.P.; Dijkshoorn, L.; Veldkamp, A.

    2000-01-01

    We started a geochemical mapping campaign in the Early Pleistocene fluviatile Kedichem Formation in the Netherlands in order to meet the demand for more information about subsurface sediment compositions. Geochemical data were collected during a sampling campaign, and about 600 samples from the

  15. Spatial prediction of the variability of Early Pleistocene subsurface sediments in the Netherlands - Part 2 : Geochemistry

    NARCIS (Netherlands)

    Huisman, D.J.; Weijers, J.P.; Dijkshoorn, L.; Veldkamp, A.

    2000-01-01

    We started a geochemical mapping campaign in the Early Pleistocene fluviatile Kedichem Formation in the Netherlands in order to meet the demand for more information about subsurface sediment compositions. Geochemical data were collected during a sampling campaign, and about 600 samples from the

  16. Two Late Pleistocene climate-driven incision/aggradation rhythms in the middle Dnieper River basin, west-central Russian Plain

    DEFF Research Database (Denmark)

    Panin, Andrei; Adamiec, Grzegorz; Buylaert, Jan-Pieter

    2017-01-01

    Pleistocene - Holocene climate cycle. The following events were detected. (1) Late MIS 5 - early MIS 4: aggradation of Terrace T1 following the deep incision at the end of MIS 6. (2) Late MIS 4 (40-30 ka): incision into Terrace T1 below the present-day river, formation of the main scarp in the bottom...... of the valley between Terrace T1 and Terrace T0/Floodplain levels. (3) MIS 2: aggradation of Terrace T0, lateral migrations of a shallow braided channel located few meters above the present-day river since ∼25 ka through the LGM. (4) 18-13 ka: incision into Terrace T0 below the modern river. Multiple...

  17. Implications of the avian fauna for paleoecology in the Early Pleistocene of the Iberian Peninsula.

    Science.gov (United States)

    Sánchez-Marco, A

    1999-01-01

    The aim of this paper is to reconstruct the landscape and climate during the formation of the Lower Pleistocene TD6 layer at Gran Dolina, Atapuerca. Habitat preferences and phenetic behavioural spectra of fossil birds are reconstructed using comparisons of fossil bird assemblages with modern avian communities. This method is based upon the phenology (seasonality and breeding status) of each species for both the fossil association and modern communities. The results indicate that more open country and wetter conditions prevailed during the early Pleistocene than were previously inferred. Copyright 1999 Academic Press.

  18. Tanque Loma, a new late-Pleistocene megafaunal tar seep locality from southwest Ecuador

    Science.gov (United States)

    Lindsey, Emily L.; Lopez R., Eric X.

    2015-01-01

    Fossil deposits in the petroleum-rich sediments of the Santa Elena Peninsula in southwestern Ecuador contain some of the largest and best-preserved assemblages of Pleistocene megafaunal remains known from the neotropics, and thus represent an opportunity to greatly expand our knowledge of Pleistocene paleoecology and the extinction of Quaternary megafauna in this region. This paper reports data from excavations at Tanque Loma, a late-Pleistocene locality on the Santa Elena Peninsula that preserves a dense assemblage of megafaunal remains in hydrocarbon-saturated sediments along with microfaunal and paleobotanical material. The megafauna bones are concentrated in and just above a ˜0.5 m thick asphaltic layer, but occur sparsely and with poorer preservation up to 1 m above this deposit. Several meters of presumed-Holocene sediments overlying the megafauna-bearing strata are rich in bones of microvertebrates including birds, squamates, and rodents. These are interpreted as raptor assemblages. While over 1000 megafaunal bones have been identified from the Pleistocene strata at Tanque Loma, more than 85% of these remains pertain to a single species, the giant ground sloth Eremotherium laurillardi. Only five other megafauna taxa have been identified from this site, including Glossotherium cf. tropicorum, Holmesina occidentalis, cf. Notiomastodon platensis, Equus (Amerhippus) c.f. santaeelenae, and a cervid tentatively assigned to cf. Odocoileus salinae based on body size and geography. No carnivores have yet been identified from Tanque Loma, and microvertebrate remains are extremely rare in the Pleistocene deposits, although terrestrial snail shells and fragmented remains of marine invertebrates are occasionally encountered. Accelerator Mass Spectrometry radiocarbon dates on Eremotherium and cf. Notiomaston bones from within and just above the asphaltic layer yielded dates of ˜17,000 - 23,500 radiocarbon years BP. Taken together, the taxonomic composition, taphonomy

  19. Late Pleistocene - Holocene development of the Tista megafan (West Bengal, India): 10Be cosmogenic and IRSL age constraints

    Science.gov (United States)

    Abrahami, Rachel; Huyghe, Pascale; van der Beek, Peter; Lowick, Sally; Carcaillet, Julien; Chakraborty, Tapan

    2018-04-01

    The Himalayan proximal foreland is characterized by Quaternary megafans, of which the formational mechanisms remain debated. The Tista megafan spreads over more than 16,000 km2 from the mountain front, where it is strongly incised, to the confluence of the Tista River with the Jamuna/Brahmaputra River, and stores sediments produced in the Sikkim Himalaya. We propose a scenario for the late Pleistocene - Holocene development of the Tista megafan based on new 10Be cosmogenic and Infra-Red Stimulated Luminescence (IRSL) age constraints, and discuss the main potential controls on its evolution. We suggest that two distal lobes developed successively downstream from a common proximal lobe. Deposition in the proximal lobe took place since at least ∼135 ka and incision began at 3.7-0.7+1.0 ka. The western distal lobe of the megafan was deposited early in the history of the megafan, when the Sikkim Himalaya catchment was drained by a tributary of the Ganga River, and was abandoned in the early Holocene (10-11 ka). The eastern, recent (active. Approximately synchronous incision between terraces in the hinterland and megafan surfaces suggests that incision propagated rapidly through the system. Our data do not evidence a direct link between incicion and tectonic processes. Aggradation and incision episodes appear more compatible with a climatic control, through changes in monsoon intensity and associated sediment flux. Depositional episodes in the Tista megafan, as elsewhere in the Himalaya and its foreland, appear to correlate with periods of strong monsoon precipitation and associated high sediment flux toward the foreland. Abandonment and incision of megafan surfaces and hinterland terraces appear associated to both the onset and the ending of phases of strong monsoon precipitation, during which the balance between water and sediment discharge changes rapidly.

  20. Palynological evidence for vegetation patterns in the Transvaal (South Africa during the late Pleistocene and Holocene

    Directory of Open Access Journals (Sweden)

    L. Scott

    1983-11-01

    Full Text Available Palynological evidence relating to the nature of Late Quaternary vegetation types and plant migrations in the Transvaal is briefly summarized. It is suggested that, after an early temperate, relatively moist phase and a subsequent relatively dry phase lasting until about 25 000 yr B.P., a vegetation-type with ericaceous elements developed. It resembled belts presently occurring above the treeline and was possibly widespread over the plains of the Transvaal during the last glacial maximum period. In the central parts of the province, warm semi-arid savanna subsequently expanded during the early Holocene and was followed by a more broad-leafed type of woodland in the late Holocene. This change probably resulted from slightly wetter and, at times, also slightly warmer and cooler conditions.

  1. A lacustrine record from Lop Nur, Xinjiang, China: Implications for paleoclimate change during Late Pleistocene

    Science.gov (United States)

    Chao, L.; Zicheng, P.; Dong, Y.; Weiguo, L.; Zhaofeng, Z.; Jianfeng, H.; Chenlin, C.

    2009-01-01

    Climate variability during the Late Pleistocene is studied from the proxies in core CK-2 drilled from the Luobei Depression (91??03???E, 40??47???N), Lop Nur in the eastern Tarim Basin, Xinjiang, China. Geophysical and geochemical properties, including magnetic susceptibility, granularity, chroma, carbonate content, loss on ignition and trace elements, have been determined to reconstruct the environmental evolution of the area during 32-9 ka BP. The chronology is established by uranium-thorium disequilibrium dating techniques. Our data suggest four paleoclimate stages, indicating glacial variations between cold-humid and warm-arid environments. A period of extreme humidity occurred during 31,900-19,200 yr BP is attributed the last glacial maximum (LGM). The period was followed by a warm-arid episode during 19,200-13,500 yr BP. Then a cold-humid interval during 13,500-12,700 yr BP may correspond to another cooling phases at high latitudes of the Northern Hemisphere. The last stage from 12,700 to 9000 yr BP has a trend that the climate turned warm and arid. The Lop Nur region is characterized by particularly humid stadials and arid interstadials. The climate variability in Lop Nur was constrained by global climate change because it is correlated with Dansgaard-Oeschger and Heinrich events, which were observed at the northern high latitudes. The synchroneity of the palaeoclimatic events suggested that cold air activity at the northern high latitudes was the most important factor that influenced the climate evolution in the Lop Nur region. A probable mechanism that involves the migration of westerly winds is proposed to interpret this synchroneity. ?? 2008 Elsevier Ltd.

  2. A Stratigraphic Pollen Record from a Late Pleistocene Cypress Forest, Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Reese, A.; Harley, G. L.; DeLong, K. L.; Bentley, S. J.; Xu, K.; Gonzalez Rodriguez, S. M.; Truong, J. T.; Obelcz, J.; Caporaso, A.

    2017-12-01

    Stratigraphic pollen analysis was performed on a layer of preserved peat found near the bottom of a 4.75m vibracore taken in 18m of water off the coast of Orange Beach, Alabama. The core was taken from a site where the remains of a previously buried bald cypress (Taxodium distichum) forest was discovered after wave action, likely from Hurricane Ivan in 2004, scoured and removed the overlying Holocene/late Pleistocene sand sheet. Many of the cypress stumps found at the site are still in growth position, and rooted in the preserved terrestrial soils below. Radiocarbon dating of the peat recovered in core DF1 suggests that the sediment is likely Marine Isotope Stage 3 (MIS 3), or earlier. We hypothesize that the site was quickly buried and preserved by floodplain aggradation associated with sea-level rise that occurred near the end of MIS 3. This rare find provides an opportunity to study in situ fossil pollen from a glacial refugium in the Northern Gulf of Mexico. Pollen results from the lowermost sections within the peat layer show an assemblage consistent with a bald cypress/tupelo gum (Nyssa aquatica) backwater. This is eventually replaced by a more open, possibly brackish, environment, dominated by grasses (Poaceae) and sedges (Cyperaceae). During this change however, there is a brief but very interesting period where the pollen assemblage is likely analogous to the modern day Atlantic Coastal Plain Blackwater Levee/Bar Forests of North and South Carolina. In this modern assemblage, as well as the core samples, birch (Betula), oak (Quercus) and bald cypress are the dominant taxa, along with a strong presence of alder (Alnus), grasses and sedges. We hypothesize that these bar forests formed on areas of higher ground, which resulted from floodplain aggradation that accompanied sea level rise at the end of MIS 3.

  3. Geochemical Characterization of Late Pleistocene and Holocene Tephra Layers from the Basin of Mexico, Central Mexico

    Science.gov (United States)

    Ortega-Guerrero, Beatriz; Newton, Anthony J.

    1998-07-01

    In order to aid palaeoenvironmental research of Late Pleistocene and Holocene deposits of central Mexico, tephra layers collected from the sediments of the Texcoco and Chalco sub-basins, in the southern part of the Basin of Mexico, are geochemically characterized and used as stratigraphic markers. The tephra layers range in composition from basaltic andesites to rhyolites and are calc-alkaline. The tephras range in age from >34,000 to ca. 2600 14C yr B.P. New names are used informally to designate correlated tephras. The Tlahuac tephra is present in Chalco, at a depth of 18 m; in the southeastern part of Texcoco, at a depth of around 10 m; and at the Tlapacoya archaeological site, where it had been mistakenly described as basaltic. This basalt-andesite tephra is dated to at least 34,000 14C yr B.P. The Tlapacoya 1 tephra is dated to between 15,020 ± 450 and 14,430 ± 190 yr B.P. and is present in all Chalco sections. The Tlapacoya 2 tephra corresponds to the previously described "pomez gruesa con fragmentos de andesita" (ca. 14,400 yr B.P.) and is present in all Chalco and Texcoco sections. The likely source of these three tephras is the volcano Popocatepetl. Tephra II at Chalco dates to 12,520 ± 135 yr B.P. and correlates with the Upper Toluca Pumice from Nevado de Toluca volcano. These represent the first geochemical glass-shard analysis of tephras from the Basin of Mexico, and so further research is necessary before a reliable tephrochronology can be established.

  4. TERRESTRIAL EFFECTS OF NEARBY SUPERNOVAE IN THE EARLY PLEISTOCENE

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B. C.; Engler, E. E. [Department of Physics and Astronomy, Washburn University, Topeka, KS 66621 (United States); Kachelrieß, M. [Institutt for fysikk, NTNU, Trondheim (Norway); Melott, A. L. [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Overholt, A. C. [Department of Science and Mathematics, MidAmerica Nazarene University, Olathe, KS 66062 (United States); Semikoz, D. V., E-mail: brian.thomas@washburn.edu [APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, F-119 75205 Paris (France)

    2016-07-20

    Recent results have strongly confirmed that multiple supernovae happened at distances of ∼100 pc, consisting of two main events: one at 1.7–3.2 million years ago, and the other at 6.5–8.7 million years ago. These events are said to be responsible for excavating the Local Bubble in the interstellar medium and depositing {sup 60}Fe on Earth and the Moon. Other events are indicated by effects in the local cosmic ray (CR) spectrum. Given this updated and refined picture, we ask whether such supernovae are expected to have had substantial effects on the terrestrial atmosphere and biota. In a first look at the most probable cases, combining photon and CR effects, we find that a supernova at 100 pc can have only a small effect on terrestrial organisms from visible light and that chemical changes such as ozone depletion are weak. However, tropospheric ionization right down to the ground, due to the penetration of ≥TeV CRs, will increase by nearly an order of magnitude for thousands of years, and irradiation by muons on the ground and in the upper ocean will increase twentyfold, which will approximately triple the overall radiation load on terrestrial organisms. Such irradiation has been linked to possible changes in climate and increased cancer and mutation rates. This may be related to a minor mass extinction around the Pliocene-Pleistocene boundary, and further research on the effects is needed.

  5. Early- versus Late-Onset Dysthymia

    Science.gov (United States)

    Sansone, Lori A.

    2009-01-01

    In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared to those with late-onset dysthymia, early-onset patients are more likely to harbor psychiatric comorbidity both on Axis I and II, exhibit less psychological resilience, and have more prominent family loadings for mood disorders. These findings suggest that this distinction is meaningful and that the early-onset subtype of dysthymia is more difficult to effectively treat. PMID:20049145

  6. The first finding of Asian black bear (Carnivora, Ursidae, Ursus (Euarctos) thibetanus G. Cuvier, 1823) in the Late Pleistocene of northern Eurasia.

    Science.gov (United States)

    Kosintsev, P A; Tiunov, M P; Gimranov, D O; Panov, V S

    2016-11-01

    An M1 tooth of Asian black bear (Ursus (Euarctos) thibetanus G. Cuvier, 1823) was found in deposits of the Tetyukhinskaya cave (Middle Sikhote-Alin, 44°35'N, 135°36'E). This finding is the first reliable evidence of Asian black bear's presence in Pleistocene of Primorye. Its morphological and morphometric descriptions are given. The period of inhabitation of U. (E.) thibetanus determined based on the radiocarbon date obtained during the study of the tooth, is 39 874 ± 133 BP (NSK-850, UGAMS-21786), which corresponds to the middle of Marine Isotope Stage 3 (MIS 3) of Late Pleistocene. The composition of ancient theriofauna indicates the existence of wide variety of landscapes in Primorye in the middle of Late Pleistocene. A refugium of forest fauna, in which species of taiga, nemoral, and Central Asian mountain-forest theriocomplexes were present, was located in southern Primorye in Late Pleistocene.

  7. Preliminary Facies Reconstruction of a Late Pleistocene Cypress Forest Discovered on the Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Gonzalez Rodriguez, S. M.; Bentley, S. J.; DeLong, K. L.; Xu, K.; Caporaso, A.; Obelcz, J. B.; Harley, G. L.; Reese, C. A.; Truong, J. T.

    2016-12-01

    We are investigating the origin and preservation of an ancient bald cypress forest (Taxodium distichum) discovered on the continental shelf seafloor, offshore of Gulf Shores, Alabama, USA, in 20 m water depth. The forest was likely buried in the late Pleistocene, possibly exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position with little evidence of decay before recent marine exposure. Radiocarbon analyses show that the forest age is near (and in some cases beyond) the limits of 14C dating, at least 41-45 ky BP. In August 2015 and July 2016, submersible vibracores (up to 5 m in length) were collected. Ongoing core analyses include: organic content (loss on ignition), granulometry, and core logging using a Geotek Multi Sensor Core Logger to generate imagery, bulk density, and x-ray fluorescence data. To bolster 14C analyses, cores collected in 2016 are presently being dated using optically stimulated luminescence. Local stratigraphy consists of a surface facies of Holocene transgressive sands, underlain by possible estuarine sediments of interbedded sand and mud (potentially Holocene or Pleistocene), overlying a swamp or delta plain facies (likely Pleistocene) containing woody debris and mud. Deeper woody facies are thought to include the soil horizons of the ancient cypress forest. Cores collected in 2016 revealed a Pleistocene paleosol beneath Holocene sands in a nearby trough. Elevation differences between swamp and paleosol horizons will be evaluated from bathymetric and subbottom data, to help characterize the preserved ancient landscape. Initial interpretation based on close proximity of Pleistocene swamp and oxidized paleosol sediments, and regional geomorphic gradients suggest that this relatively diverse assemblage of facies developed up to tens of km from the glacial-age coastline, and relatively rapid burial prevented erosion by coastal processes during the Holocene transgression thus preserving the tree stumps and wood debris.

  8. Pollen analyses of Pleistocene hyaena coprolites from Montenegro and Serbia

    Directory of Open Access Journals (Sweden)

    Argant Jacqueline

    2007-01-01

    Full Text Available The results of pollen analyses of hyaena coprolites from the Early Pleistocene cave of Trlica in northern Montenegro and the Late Pleistocene cave of Baranica in southeast Serbia are described. The Early Pleistocene Pachycrocuta brevirostris, and the Late Pleistocene Crocuta spelaea are coprolite-producing species. Although the pollen concentration was rather low, the presented analyses add considerably to the much-needed knowledge of the vegetation of the central Balkans during the Pleistocene. Pollen extracted from a coprolite from the Baranica cave indicates an open landscape with the presence of steppe taxa, which is in accordance with the recorded conditions and faunal remains. Pollen analysis of the Early Pleistocene samples from Trlica indicate fresh and temperate humid climatic conditions, as well as the co-existence of several biotopes which formed a mosaic landscape in the vicinity of the cave.

  9. The medial pterygoid tubercle in the Atapuerca Early and Middle Pleistocene mandibles: evolutionary implications.

    Science.gov (United States)

    Bermúdez de Castro, José-María; Quam, Rolf; Martinón-Torres, María; Martínez, Ignacio; Gracia-Téllez, Ana; Arsuaga, Juan Luís; Carbonell, Eudald

    2015-01-01

    Numerous studies have attempted to identify the presence of uniquely derived (autoapomorphic) Neandertal features. Here, we deal with the medial pterygoid tubercle (MTP), which is usually present on the internal face of the ascending ramus of Neandertal specimens. Our study stems from the identification of a hypertrophied tubercle in ATD6-96, an Early Pleistocene mandible recovered from the TD6 level of the Atapuerca-Gran Dolina site and attributed to Homo antecessor. Our review of the literature and study of numerous original fossil specimens and high quality replicas confirm that the MTP occurs at a high frequency in Neandertals (ca. 89%) and is also present in over half (ca. 55%) of the Middle Pleistocene Sima de los Huesos (SH) hominins. In contrast, it is generally absent or minimally developed in other extinct hominins, but can be found in variable frequencies (Pleistocene and recent H. sapiens samples. The presence of this feature in ATD6-96 joins other traits shared by H. antecessor, the SH hominins and Neandertals. Since the TD6 hominins have been attributed either to MIS 21 or to MIS 25, it seems that a suite of assumed derived Neandertal features appeared in the Early Pleistocene, and they should be interpreted as synapomorphies shared among different taxa. We suggest that H. antecessor, the SH hominins and Neandertals shared a common ancestor in which these features appeared during the Early Pleistocene. The presence of the MTP in taxa other than H. neanderthalensis precludes this feature from being a Neandertal autapomorphy. © 2014 Wiley Periodicals, Inc.

  10. Acinonyx pardinensis (Carnivora, Felidae) from the Early Pleistocene of Pantalla (Italy): predatory behavior and ecological role of the giant Plio-Pleistocene cheetah

    Science.gov (United States)

    Cherin, Marco; Iurino, Dawid Adam; Sardella, Raffaele; Rook, Lorenzo

    2014-03-01

    The site of Pantalla (central Italy) yielded a rich late Villafranchian (Early Pleistocene) faunal assemblage, which includes some well-preserved large mammal skulls. We describe here two nearly complete crania and a left hemimandible of Acinonyx pardinensis from this locality, representing the most complete cranial material of this species in Europe. These finds allowed us to define more clearly the craniodental morphology of A. pardinensis. Similarly to the forms from North Africa and China, the giant cheetah from Pantalla has a more generalized skull than the living Acinonyx jubatus, showing some primitive, pantherine-like features such as the less domed dorsal outline of the cranium, the more developed sagittal and nuchal crests and the less bowed zygomatic arches. High-resolution CT scans of the specimens were used to obtain the first 3D model of a cranium with articulated mandible of A. pardinensis. Starting from the insertion areas on this model we reconstructed the jaw muscles of the Pantalla felid, confirming its affinities with pantherine felines. In the light of the musculoskeletal skull anatomy and the average body mass (about 80 kg), it is likely that A. pardinensis could kill large prey through a hunting strategy more similar to pantherine cats than to the living cheetah.

  11. Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

    Science.gov (United States)

    Brown, Kyle S.; Oestmo, Simen; Pereira, Telmo; Ranhorn, Kathryn L.; Schoville, Benjamin J.; Marean, Curtis W.

    2017-01-01

    There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5–6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, ‘place provisioning’, longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS

  12. The first hominin from the early Pleistocene paleocave of Haasgat, South Africa.

    Science.gov (United States)

    Leece, A B; Kegley, Anthony D T; Lacruz, Rodrigo S; Herries, Andy I R; Hemingway, Jason; Kgasi, Lazarus; Potze, Stephany; Adams, Justin W

    2016-01-01

    Haasgat is a primate-rich fossil locality in the northeastern part of the Fossil Hominid Sites of South Africa UNESCO World Heritage Site. Here we report the first hominin identified from Haasgat, a partial maxillary molar (HGT 500), that was recovered from an ex situ calcified sediment block sampled from the locality. The in situ fossil bearing deposits of the Haasgat paleokarstic deposits are estimated to date to slightly older than 1.95 Ma based on magnetobiostratigraphy. This places the hominin specimen at a critical time period in South Africa that marks the last occurrence of Australopithecus around 1.98 Ma and the first evidence of Paranthropus and Homo in the region between ∼2.0 and 1.8 Ma. A comprehensive morphological evaluation of the Haasgat hominin molar was conducted against the current South African catalogue of hominin dental remains and imaging analyses using micro-CT, electron and confocal microscopy. The preserved occlusal morphology is most similar to Australopithecus africanus or early Homo specimens but different from Paranthropus. Occlusal linear enamel thickness measured from micro-CT scans provides an average of ∼2.0 mm consistent with Australopithecus and early Homo. Analysis of the enamel microstructure suggests an estimated periodicity of 7-9 days. Hunter-Schreger bands appear long and straight as in some Paranthropus, but contrast with this genus in the short shape of the striae of Retzius. Taken together, these data suggests that the maxillary fragment recovered from Haasgat best fits within the Australopithecus-early Homo hypodigms to the exclusion of the genus Paranthropus. At ∼1.95 Ma this specimen would either represent another example of late occurring Australopithecus or one of the earliest examples of Homo in the region. While the identification of this first hominin specimen from Haasgat is not unexpected given the composition of other South African penecontemporaneous site deposits, it represents one of the few hominin

  13. The first hominin from the early Pleistocene paleocave of Haasgat, South Africa

    Directory of Open Access Journals (Sweden)

    AB Leece

    2016-05-01

    Full Text Available Haasgat is a primate-rich fossil locality in the northeastern part of the Fossil Hominid Sites of South Africa UNESCO World Heritage Site. Here we report the first hominin identified from Haasgat, a partial maxillary molar (HGT 500, that was recovered from an ex situ calcified sediment block sampled from the locality. The in situ fossil bearing deposits of the Haasgat paleokarstic deposits are estimated to date to slightly older than 1.95 Ma based on magnetobiostratigraphy. This places the hominin specimen at a critical time period in South Africa that marks the last occurrence of Australopithecus around 1.98 Ma and the first evidence of Paranthropus and Homo in the region between ∼2.0 and 1.8 Ma. A comprehensive morphological evaluation of the Haasgat hominin molar was conducted against the current South African catalogue of hominin dental remains and imaging analyses using micro-CT, electron and confocal microscopy. The preserved occlusal morphology is most similar to Australopithecus africanus or early Homo specimens but different from Paranthropus. Occlusal linear enamel thickness measured from micro-CT scans provides an average of ∼2.0 mm consistent with Australopithecus and early Homo. Analysis of the enamel microstructure suggests an estimated periodicity of 7–9 days. Hunter–Schreger bands appear long and straight as in some Paranthropus, but contrast with this genus in the short shape of the striae of Retzius. Taken together, these data suggests that the maxillary fragment recovered from Haasgat best fits within the Australopithecus—early Homo hypodigms to the exclusion of the genus Paranthropus. At ∼1.95 Ma this specimen would either represent another example of late occurring Australopithecus or one of the earliest examples of Homo in the region. While the identification of this first hominin specimen from Haasgat is not unexpected given the composition of other South African penecontemporaneous site deposits, it represents

  14. Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea

    Science.gov (United States)

    Barrows, T.T.; Hope, G.S.; Prentice, M.L.; Fifield, L.K.; Tims, S.G.

    2011-01-01

    The Mt Giluwe shield volcano was the largest area glaciated in Papua New Guinea during the Pleistocene. Despite minimal cooling of the sea surface during the last glacial maximum, glaciers reached elevations as low as 3200 m. To investigate changes in the extent of ice through time we have re-mapped evidence for glaciation on the southwest flank of Mt Giluwe. We find that an ice cap has formed on the flanks of the mountain on at least three, and probably four, separate occasions. To constrain the ages of these glaciations we present 39 new cosmogenic 36Cl exposure ages complemented by new radiocarbon dates. Direct dating of the moraines identifies that the maximum extent of glaciation on the mountain was not during the last glacial maximum as previously thought. In conjunction with existing potassium/argon and radiocarbon dating, we recognise four distinct glacial periods between 293-306 ka (Gogon Glaciation), 136-158 ka (Mengane Glaciation), centred at 62 ka (Komia Glaciation) and from >20.3-11.5 ka (Tongo Glaciation). The temperature difference relative to the present during the Tongo Glaciation is likely to be of the order of at least 5 ??C which is a minimum difference for the previous glaciations. During the Tongo Glaciation, ice was briefly at its maximum for less than 1000 years, but stayed near maximum levels for nearly 4000 years, until about 15.4 ka. Over the next 4000 years there was more rapid retreat with ice free conditions by the early Holocene. ?? 2011 Elsevier Ltd.

  15. Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse.

    Science.gov (United States)

    Orlando, Ludovic; Ginolhac, Aurélien; Zhang, Guojie; Froese, Duane; Albrechtsen, Anders; Stiller, Mathias; Schubert, Mikkel; Cappellini, Enrico; Petersen, Bent; Moltke, Ida; Johnson, Philip L F; Fumagalli, Matteo; Vilstrup, Julia T; Raghavan, Maanasa; Korneliussen, Thorfinn; Malaspinas, Anna-Sapfo; Vogt, Josef; Szklarczyk, Damian; Kelstrup, Christian D; Vinther, Jakob; Dolocan, Andrei; Stenderup, Jesper; Velazquez, Amhed M V; Cahill, James; Rasmussen, Morten; Wang, Xiaoli; Min, Jiumeng; Zazula, Grant D; Seguin-Orlando, Andaine; Mortensen, Cecilie; Magnussen, Kim; Thompson, John F; Weinstock, Jacobo; Gregersen, Kristian; Røed, Knut H; Eisenmann, Véra; Rubin, Carl J; Miller, Donald C; Antczak, Douglas F; Bertelsen, Mads F; Brunak, Søren; Al-Rasheid, Khaled A S; Ryder, Oliver; Andersson, Leif; Mundy, John; Krogh, Anders; Gilbert, M Thomas P; Kjær, Kurt; Sicheritz-Ponten, Thomas; Jensen, Lars Juhl; Olsen, Jesper V; Hofreiter, Michael; Nielsen, Rasmus; Shapiro, Beth; Wang, Jun; Willerslev, Eske

    2013-07-04

    The rich fossil record of equids has made them a model for evolutionary processes. Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr BP). Our data represent the oldest full genome sequence determined so far by almost an order of magnitude. For comparison, we sequenced the genome of a Late Pleistocene horse (43 kyr BP), and modern genomes of five domestic horse breeds (Equus ferus caballus), a Przewalski's horse (E. f. przewalskii) and a donkey (E. asinus). Our analyses suggest that the Equus lineage giving rise to all contemporary horses, zebras and donkeys originated 4.0-4.5 million years before present (Myr BP), twice the conventionally accepted time to the most recent common ancestor of the genus Equus. We also find that horse population size fluctuated multiple times over the past 2 Myr, particularly during periods of severe climatic changes. We estimate that the Przewalski's and domestic horse populations diverged 38-72 kyr BP, and find no evidence of recent admixture between the domestic horse breeds and the Przewalski's horse investigated. This supports the contention that Przewalski's horses represent the last surviving wild horse population. We find similar levels of genetic variation among Przewalski's and domestic populations, indicating that the former are genetically viable and worthy of conservation efforts. We also find evidence for continuous selection on the immune system and olfaction throughout horse evolution. Finally, we identify 29 genomic regions among horse breeds that deviate from neutrality and show low levels of genetic variation compared to the Przewalski's horse. Such regions could correspond to loci selected early during domestication.

  16. Late Pleistocene and Holocene Hydroclimate Variability in the Tropical Andes from Alpine Lake Sediments, Cordillera de Mérida, Venezuela

    Science.gov (United States)

    Larsen, D. J.; Abbott, M. B.; Polissar, P. J.

    2014-12-01

    The tropics play a major role in the global hydrologic cycle and changes to tropical rainfall patterns have critical implications for water resources and ecosystem dynamics over large geographic scales. In tropical South America, late Pleistocene and Holocene precipitation variability has been documented in geologic records and associated with numerous external and internal variables, including changes in summer insolation, South American summer monsoon strength, Pacific Ocean sea surface temperatures, continental moisture recycling, and other climate processes. However, there are few records from the northern hemisphere tropical Americas, a key region for understanding interhemispheric linkages and the drivers of tropical hydroclimate variability. Here, we present a ~13 ka record of coupled hydroclimate and environmental changes from Laguna Brava, a small (~0.07 km2), hydrologically closed lake basin situated at 2400 m asl in the Cordillera de Mérida, Venezuela. Sediment cores collected from varying water depths and proximity to shore are placed in a chronologic framework using radiocarbon ages from terrestrial macrofossils, and analyzed for a suite of physical, bulk geochemical, and stable isotopic parameters. Compound specific hydrogen isotope (D/H) measurements of terrestrial plant waxes (long-chain n-alkanes) show a sharp increase in the late Pleistocene, followed by a long-term trend toward more negative values that suggest a ~20‰ decrease in the D/H ratios of South American tropical precipitation during the Holocene. This pattern is consistent in sign and magnitude to other South American precipitation reconstructions from both hemispheres, indicating interhemispheric similarities in tropical hydroclimate variability. Superimposed on this continent-scale trend are changes in moisture balance and environmental conditions in the Venezuelan Andes. We reconstruct these parameters at Laguna Brava at multidecadal and centennial resolution and evaluate this

  17. Drainage system inversion in the Guadalentin Depression during the Late Pleistocene-Holocene (Murcia, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Calmel-Avila, M.; Silva, P. G.; Bardaji, T.; Goy, J. L.; Zazo, C.

    2009-07-01

    This article presents the results of studies conducted in the central sector of Guadalentin depression (Murcia) for the abnormal accumulation (more than 17 m) of Pleistocene and Holocene deposits upstream of Romeral tectonic threshold (Librilla). {sup 1}4C dating. ruins and archaeological sites, together with its stratigraphic analysis show that the three sequences that constitute the Holocene detrital filling of the Depression, prograded are superimposed on the upper Pleistocene travertine upstream from the confluence of the River Guadalentin the Rambla de Librilla. Between Librilla and threshold Romeral Holocene deposits only appear along the left bank (15-17m). By contrast the right side shows significant lifting of the Pleistocene travertine up area Romeral threshold, where the substrate allora Neogene. (Author) 11 refs.

  18. Late Pleistocene dust dynamics and pedogenesis in Southern Eurasia - Detailed insights from the loess profile Toshan (NE Iran)

    Science.gov (United States)

    Vlaminck, Stefan; Kehl, Martin; Rolf, Christian; Franz, Sven Oliver; Lauer, Tobias; Lehndorff, Eva; Frechen, Manfred; Khormali, Farhad

    2018-01-01

    In southern Eurasia recurrent phases of aridization, dust source extension and enhanced Aeolian sedimentation alternated with moister intervals, promoting reduced deflation areas and dust accumulation in the context of late Pleistocene climate changes. Weathering and soil forming intensity in this greater region are, hence, mainly governed by fluctuations in the balance between dust supply and moisture availability. Among the hitherto known sections, the Toshan loess-soil sequence (LPS) represents a key site due to the quality of the record and the multitude of available data giving detailed insights into the timing and magnitude of dust accumulation and soil formation of the region. To elucidate these dynamics for much of the past 130.000 years bulk mineralogical and geochemical data are presented supplemented by a high resolution magnetic susceptibility record and by the results of a detailed micromorphological study of loess at Toshan. The last interglacial Luvisol/Phaeozem-like (∼MIS 5e) and the early glacial interstadial steppic palaeosols (∼MIS 5 c and a) are characterized by gradually increasing grain-size and decreasing degrees in decomposition of micaceous and mafic minerals. Pronounced feldspar weathering is detected in the last interglacial and modern soils only, which formed under reduced or absent dust deposition on penultimate and last glacial loess, respectively (postsedimentary). The overall pedosedimentary conditions correspond to large scale trends of increasing drought, dust accumulation and wind strength in southern Eurasia in relation to decreasing moisture availability towards the early Pleniglacial (∼MIS 4), causing soil formation under ongoing dust deposition (synsedimentary). Similar intervals of synsedimentary soil formation are recorded during the interglacial/interstadial-stadial transitions of the early glacial and during pleniglacial (∼MIS 4 to 2) interstadials. The latter are marked by gradual increases in magnetic

  19. Probe into the origin, development and evolution model of shelf desertizational environment in the last stage of Late Pleistocene

    Science.gov (United States)

    Yu, Hong-Jun; Liu, Jing-Pu; Shan, Qiu-Mei

    1998-12-01

    Based on study of China's shelf paleoenvironment, this paper summarises the definition of shelf desertization that occurred in the last stage of Late Pleistocene, and discusses the background of its formation and evolution process. Study of shallow layer profiler records and core data revealed that cold-dry aeolian erosion was the major exogenic force on the exposed shelf. Under the prevailing paleo-winter monsoon, part of the exposed marine stratum disintegrated into sand and then desertization occurred. The fine sediments were blown away and deposited on the leeward to form derivative loess deposits.

  20. Ancient DNA analyses exclude humans as the driving force behind late Pleistocene musk ox (Ovibos moschatus) population dynamics

    DEFF Research Database (Denmark)

    Campos, Paula; Willerslev, Eske; Sher, Andrei

    2010-01-01

    The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived......, as it was the geographic origin of all samples studied and held a large diverse population until local extinction at approximately 45,000 radiocarbon years before present ((14)C YBP). Subsequently, musk ox genetic diversity reincreased at ca. 30,000 (14)C YBP, recontracted at ca. 18,000 (14)C YBP, and finally recovered...

  1. Late Pleistocene and Holocene activity of the Atacazo-Ninahuilca Volcanic Complex (Ecuador)

    NARCIS (Netherlands)

    Hidalgo, Silvana; Monzier, Michel; Almeida, Eduardo; Chazot, Gilles; Eissen, Jean-Philippe; van der Plicht, Johannes; Hall, Minard L.

    2008-01-01

    The Atacazo-Ninahuilca Volcanic Complex (ANVC) is located in the Western Cordillera of Ecuador, 10 km southwest of Quito. At least six periods of Pleistocene to Holocene activity (N1 to N6) have been preserved in the geologic record as tephra fallouts and pyroclastic flow deposits. New field data,

  2. Small mammal diversity loss in response to late-Pleistocene climatic change.

    Science.gov (United States)

    Blois, Jessica L; McGuire, Jenny L; Hadly, Elizabeth A

    2010-06-10

    Communities have been shaped in numerous ways by past climatic change; this process continues today. At the end of the Pleistocene epoch about 11,700 years ago, North American communities were substantially altered by the interplay of two events. The climate shifted from the cold, arid Last Glacial Maximum to the warm, mesic Holocene interglacial, causing many mammal species to shift their geographic distributions substantially. Populations were further stressed as humans arrived on the continent. The resulting megafaunal extinction event, in which 70 of the roughly 220 largest mammals in North America (32%) became extinct, has received much attention. However, responses of small mammals to events at the end of the Pleistocene have been much less studied, despite the sensitivity of these animals to current and future environmental change. Here we examine community changes in small mammals in northern California during the last 'natural' global warming event at the Pleistocene-Holocene transition and show that even though no small mammals in the local community became extinct, species losses and gains, combined with changes in abundance, caused declines in both the evenness and richness of communities. Modern mammalian communities are thus depauperate not only as a result of megafaunal extinctions at the end of the Pleistocene but also because of diversity loss among small mammals. Our results suggest that across future landscapes there will be some unanticipated effects of global change on diversity: restructuring of small mammal communities, significant loss of richness, and perhaps the rising dominance of native 'weedy' species.

  3. A remarkable collection of Late Pleistocene reindeer (Rangifer tarandus) remains from Woerden (The Netherlands)

    NARCIS (Netherlands)

    van Kolfschoten, Thijs; van der Jagt, Inge; Beeren, Zoe; Argiti, Vasiliki; van der Leije, Judith; van Essen, Hans; Busschers, Freek S.; Stoel, Pieter; van der Plicht, Hans

    2011-01-01

    Woerden, in the central part of The Netherlands, is a locality where the amateur-archaeologist Pieter Stoel collected several thousands of fossil mammalian remains of Pleistocene age. The stratigraphically-mixed assemblage includes a broad variety of taxa including species that are indicative of

  4. First record of Smilodon fatalis Leidy, 1868 (Felidae, Machairodontinae) in the extra-Andean region of South America (late Pleistocene, Sopas Formation), Uruguay: Taxonomic and paleobiogeographic implications

    Science.gov (United States)

    Manzuetti, Aldo; Perea, Daniel; Ubilla, Martín; Rinderknecht, Andrés

    2018-01-01

    The Felidae are known in South America from the Ensenadan Stage/Age onwards. Among them, machairodonts of the genus Smilodon stand out. Three species are recognized, and all three are present on the continent: S. gracilis from the early-middle Pleistocene in north-east Venezuela; S. fatalis, found only in Lujanian sediments on the west side of the Andes (north-west of Peru and south-west of Ecuador); and S. populator, which inhabited the eastern part of the Andes during the Ensenadan and Lujanian. This distribution has led to the suggestion that the last two felids were allopatric during the Lujanian. Here, we report the first evidence of S. fatalis in the eastern part of the continent (Sopas Formation, late Pleistocene of Uruguay), based on an almost complete skull. This finding not only enlarges its distribution in South America but questions the idea of allopatric distribution. It also adds a new component to the mammalian predator trophic level of Uruguay, with the capacity to predate large South American herbivores and megaherbivores. A revision of materials previously assigned to S. populator in the extra-Andean zone of South America will be required.

  5. Climatic fluctuations as a significant contributing factor for volcanic collapses. Evidence from Mexico during the Late Pleistocene

    Science.gov (United States)

    Capra, L.; Bernal-Uruchurtu, J. P.; Carrasco, G.

    2013-05-01

    Climate oscillations have significantly contributed to the planet's evolution, including volcanic activity. Major glaciations have been considered not only as a triggering mechanism for large magmatic eruptions but also inducing volcano instability. Generally, volcano instability can be inferred from detailed volcanological and structural studies of a volcano and its associated depositional sequence, but the triggering mechanism has been always difficult to infer. In this paper, we present evidence of how climatic variations during the Late Pleistocene could have forced sector collapses of the main Mexican stratovolcanoes and enhanced the mobility of associated massive flows inducing the transformation of debris avalanche into debris flows. In particular, the climatic record based on atmospheric moisture content from robustly dated lake record from Guatemala and a U/Th dated speleothem from New Mexico are used here as indicators of summer and winter precipitation. Depositional sequences associated with Late Pleistocene sector collapses of Volcan de Colima, Nevado de Toluca, Citlaltepetl (Pico de Orizaba) and Cofre de Perote volcanoes are here analyzed. Comparing the timing of the event with the climatic record, a combination of summer and/or winter pluvial conditions could have forced and triggered the failure of already unstable volcanoes, even during glacier advances (as for the Citlaltepetl event). Independently of the main cause of the volcano instability (magmatic or tectonic) it is important to highlight that the climatic factor played an important role in enhancing the volcano instability and promoted the lateral transformation of debris avalanches, which under dry conditions would have affected more limited areas.

  6. New radiocarbon dates for terminal Pleistocene and early Holocene settlements in West Turkana, northern Kenya

    Science.gov (United States)

    Beyin, Amanuel; Prendergast, Mary E.; Grillo, Katherine M.; Wang, Hong

    2017-07-01

    The Turkana Basin in northern Kenya is located in an environmentally sensitive region along the eastern African Rift system. Lake Turkana's sensitivity to fluctuations in precipitation makes this an ideal place to study prehistoric human adaptations during key climatic transitions. Here we present eleven radiocarbon dates from two recently excavated sites in West Turkana, Kokito 01 and Kokito 02. The sites span the Pleistocene-Holocene transition, a time of fluctuating lake levels and novel cultural responses within the region. Several scenarios are laid out for the interpretation of site chronologies, and these are discussed with reference to the terminal Pleistocene and early Holocene chronological record for the region. Given the paucity of well-dated sites from this timespan in the Turkana Basin, the new radiocarbon dates are an important step toward establishing human settlement history and associated cultural developments in the region.

  7. Early and late arrhythmogenic effects of doxorubicin.

    Science.gov (United States)

    Kilickap, Saadettin; Barista, Ibrahim; Akgul, Ebru; Aytemir, Kudret; Aksoy, Sercan; Tekuzman, Gulten

    2007-03-01

    To determine the incidence of early and late arrhythmogenic effects of doxorubicin-containing chemotherapy regimens. A prospective study including 29 patients who were treated with doxorubicin-containing regimens. Cardiac evaluation was based on 24-hour electrocardiographic monitorization (Holter), which was performed during the first cycle of doxorubicin-containing regimens, as well as after the last cycle of chemotherapy. The mean age of the patients was 45.8 +/- 15.1 (range 18-69). Holter records obtained during the first cycle of treatment revealed varying arrhythmias in 19 patients (65.5%) and in 18 (62.1%) patients after completion of therapy. One patient presented with syncope and both Mobitz Type 2 atrioventricular block and complete atrioventricular block were demonstrated. The patient subsequently underwent permanent pacemaker implantation. Doxorubicin may result in arrhythmias both in early and late periods of treatment. These arrhythmias are rarely life threatening.

  8. Late Pleistocene leopards across Europe - northernmost European German population, highest elevated records in the Swiss Alps, complete skeletons in the Bosnia Herzegowina Dinarids and comparison to the Ice Age cave art

    Science.gov (United States)

    Diedrich, Cajus G.

    2013-09-01

    European leopard sites in Europe demonstrate Early/Middle Pleistocene out of Africa lowland, and Late Pleistocene Asian alpine migrations being driven by climatic changes. Four different European Pleistocene subspecies are known. The final European Late Pleistocene “Ice Age leopard” Panthera pardus spelaea (Bächler, 1936) is validated taxonomically. The skull shows heavy signs of sexual dimorphism with closest cranial characters to the Caucasian Panthera pardus ciscaucasica (Persian leopard). Late Pleistocene leopards were distributed northernmost, up to S-England with the youngest stratigraphic records by skeletons and cave art in the MIS 2/3 (about 32,000-26,000 BP). The oldest leopard painting left by Late Palaeolithics (Aurignacians/Gravettians) in the Chauvet Cave (S-France) allows the reconstruction of the Ice Age leopard fur spot pattern being close to the snow or Caucasian leopards. The last Ice Age glacial leopard habitat was the mountain/alpine boreal forest (not mammoth steppe lowland), where those hunted even larger prey such as alpine game (Ibex, Chamois). Into some lairs, those imported their prey by short-term cave dwelling (e.g. Baumann's Cave, Harz Mountains, Germany). Only Eurasian Ice Age leopards specialized, similar as other Late Pleistocene large felids (steppe lions), on cave bear predation/scavenging partly very deep in caves. In Vjetrenica Cave (Dinarid Mountains, Bosnia Herzegovina), four adult leopards (two males/two females) of the MIS 3 were found about two km deep from the entrance in a cave bear den, near to one cave bear skeleton, that remained articulated in its nest. Leopards died there, partly being trapped by raising water levels of an active ponor stream, but seem to have been killed possibly either, similar as for lions known, in battles with cave bears in several cave bear den sites of Europe (e.g. Baumann's Cave, Wildkirchli Cave, Vjetrenica Cave). At other large cave sites, with overlap of hyena, wolf and dhole dens at

  9. Early- versus Late-Onset Systemic Sclerosis

    Science.gov (United States)

    Alba, Marco A.; Velasco, César; Simeón, Carmen Pilar; Fonollosa, Vicent; Trapiella, Luis; Egurbide, María Victoria; Sáez, Luis; Castillo, María Jesús; Callejas, José Luis; Camps, María Teresa; Tolosa, Carles; Ríos, Juan José; Freire, Mayka; Vargas, José Antonio; Espinosa, Gerard

    2014-01-01

    Abstract Peak age at onset of systemic sclerosis (SSc) is between 20 and 50 years, although SSc is also described in both young and elderly patients. We conducted the present study to determine if age at disease onset modulates the clinical characteristics and outcome of SSc patients. The Spanish Scleroderma Study Group recruited 1037 patients with a mean follow-up of 5.2 ± 6.8 years. Based on the mean ± 1 standard deviation (SD) of age at disease onset (45 ± 15 yr) of the whole series, patients were classified into 3 groups: age ≤30 years (early onset), age between 31 and 59 years (standard onset), and age ≥60 years (late onset). We compared initial and cumulative manifestations, immunologic features, and death rates. The early-onset group included 195 patients; standard-onset group, 651; and late-onset, 191 patients. The early-onset group had a higher prevalence of esophageal involvement (72% in early-onset compared with 67% in standard-onset and 56% in late-onset; p = 0.004), and myositis (11%, 7.2%, and 2.9%, respectively; p = 0.009), but a lower prevalence of centromere antibodies (33%, 46%, and 47%, respectively; p = 0.007). In contrast, late-onset SSc was characterized by a lower prevalence of digital ulcers (54%, 41%, and 34%, respectively; p < 0.001) but higher rates of heart conduction system abnormalities (9%, 13%, and 21%, respectively; p = 0.004). Pulmonary hypertension was found in 25% of elderly patients and in 12% of the youngest patients (p = 0.010). After correction for the population effects of age and sex, standardized mortality ratio was shown to be higher in younger patients. The results of the present study confirm that age at disease onset is associated with differences in clinical presentation and outcome in SSc patients. PMID:24646463

  10. Geographic and temporal trends in proboscidean and human radiocarbon histories during the late Pleistocene

    Science.gov (United States)

    Ugan, Andrew; Byers, David

    2007-12-01

    The causes of large animal extinctions at the end of the Pleistocene remain a hotly debated topic focused primarily on the effects of human over hunting and climate change. Here we examine multiple, large radiocarbon data sets for humans and extinct proboscideans and explore how variation in their temporal and geographic distributions were related prior to proboscidean extinction. These data include 4532 archaeological determinations from Europe and Siberia and 1177 mammoth and mastodont determinations from Europe, Siberia, and North America. All span the period from 45,000 to 12,000 calendar years BP. We show that while the geographic ranges of dated human occupations and proboscidean remains overlap across the terminal Pleistocene of the Old World, the two groups remain largely segregated and increases in the frequency of human occupations do not coincide with declines in proboscidean remains. Prior to the Last Glacial Maximum (LGM; ca 21,000 years BP), archaeological 14C determinations increase slightly in frequency worldwide while the frequency of dated proboscidean remains varies depending on taxon and location. After the LGM, both sympatric and allopatric groups of humans and proboscideans increase sharply as climatic conditions ameliorate. Post-LGM radiocarbon frequencies among proboscideans peak at different times, also depending upon taxon and location. Woolly mammoths in Beringia reach a maximum and then decline beginning between 16,000 and 15,500 years BP, woolly mammoths in Europe and Siberia ca 14,500 and 13,500 BP, and Columbian mammoth and American mastodont only after 13,000 BP. Declines among woolly mammoths appear to coincide with the restructuring of biotic communities following the Pleistocene-Holocene transition.

  11. Didelphidae marsupials (Mammalia, Didelphimorphia from the Late Pleistocene deposit of the Gruta dos Moura Cave, northern Brazil

    Directory of Open Access Journals (Sweden)

    Patricia Villa Nova

    2015-03-01

    Full Text Available The present study acknowledges the diversity of fossil marsupials from the Gruta dos Moura cave, as well as environmental and climatic aspects during the Quaternary. The results show that this is the largest diversity of Pleistocene marsupials recorded in a single cave: Didelphis albiventris, D. aurita, Gracilinanus agilis, G. microtarsus, Marmosa murina, Monodelphis brevicaudata, M. domesticaand Sairadelphys tocantinensis. Furthermore, the described specimens are also part of the only fossil assemblage unequivocally referable to the late Pleistocene. Paleontological studies suggest an intimate association with dry and open environments with high abundance of water sources. Since most of the identified taxa are characteristic of open forests and gallery forests, this could represent the actual environment around the Gruta dos Moura cave. Recent studies identified sympatric occurrences between species from open and dry environments and species from humid forests that were identified among our material and are characteristic of humid regions. Therefore, these species could inhabit gallery forests and capons, or even ecotones, inside a dry and open environment. Moreover, the extinction of Sairadelphyscould also indicate that the climatic and environmental conditions changed or that the past environment was more heterogeneous than the current environment of the region.

  12. Dama roberti, a new species of deer from the early Middle Pleistocene of Europe, and the origins of modern fallow deer

    Science.gov (United States)

    Breda, Marzia; Lister, Adrian M.

    2013-06-01

    The ancestry of the modern fallow deer, Dama dama, has been tentatively traced back to Pliocene/Early Pleistocene forms referred to 'Pseudodama', characterized by unpalmated three- or four-point antlers. By the late Middle Pleistocene, Dama with palmated antlers appears, as Dama dama clactoniana. However, fallow deer from the interim period, the early Middle Pleistocene, are poorly-known. A new specimen from Pakefield (Suffolk, UK), represented by a portion of cranium with a substantial part of both antlers plus a mandible and scapula, is the most complete medium-sized deer specimen from the British early Middle Pleistocene (ca 700 ka). The position and orientation of the basal tine, together with dental characters and mandibular morphology, are typical of fallow deer. The narrow palmation is reminiscent of D. dama clactoniana, but the lack of palmation tines is unique. Moreover, the lack of second (and third) tines in an adult specimen differs from both D. dama dama and D. d. clactoniana, being a primitive character shared with the last representatives of 'Pseudodama' which, on the other hand, has a circular beam lacking any palmation. This combination of features justifies the erection of a new species provisionally placed within the genus Dama, Dama roberti n. sp. Another specimen, from Soleilhac (Auvergne, France), represented by portions of the two antlers, a mandible and a tibia, shares antler morphology with the Pakefield specimen and can be ascribed to the same new species. Isolated antler and dental remains from coeval British sites are tentatively ascribed to D. roberti n. sp. The new species has implications for the ancestry of modern fallow deer.

  13. Discontinuity of human presence at Atapuerca during the early Middle Pleistocene: a matter of ecological competition?

    Science.gov (United States)

    Rodríguez-Gómez, Guillermo; Mateos, Ana; Martín-González, Jesús Angel; Blasco, Ruth; Rosell, Jordi; Rodríguez, Jesús

    2014-01-01

    Increasing evidence suggests that the European human settlement is older than 1.2 Ma. However, there is a fierce debate about the continuity or discontinuity of the early human settlement of Europe. In particular, evidence of human presence in the interval 0.7-0.5 Ma is scarce in comparison with evidence for the previous and later periods. Here, we present a case study in which the environmental conditions at Sierra de Atapuerca in the early Middle Pleistocene, a period without evidence of human presence, are compared with the conditions in the previous period, for which a relatively intense human occupation is documented. With this objective in mind, the available resources for a human population and the intensity of competition between secondary consumers during the two periods are compared using a mathematical model. The Gran Dolina site TD8 level, dated to 0.7-0.6 Ma, is taken as representative of the period during which Atapuerca was apparently not occupied by humans. Conditions at TD8 are compared with those of the previous period, represented by the TD6-2 level, which has yielded abundant evidence of intense human occupation. The results show that survival opportunities for a hypothetical human population were lower at TD8 than they were at TD6-2. Increased resource competition between secondary consumers arises as a possible explanation for the absence of human occupation at Atapuerca in the early Middle Pleistocene.

  14. First accelerator mass spectrometry {sup 14}C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, T.W. Jr.; Semken, H.A. Jr.; Graham, R.W.; Klippel, W.F.; Markova, A.; Smirnov, N.G.; Southon, J.

    1999-10-01

    Worldwide late Pleistocene terrestrial mammal faunas are characterized by stratigraphic associations of species that now have exclusive geographic ranges. These have been interpreted as either taphonomically mixed or representative of communities that no longer exist. Accelerator mass spectrometry {sup 14}C dates (n = 60) on single bones of stratigraphically associated fossil micromammals from two American and two Russian sites document for the first time that currently allopatric mammals occurred together between 12,000 and 22,000 yr B.P. on two continents. The existence of mammal communities without modern analogs demonstrates that Northern Hemisphere biological communities are ephemeral and that many modern biomes are younger than 12 ka. Future climate change may result in new nonanalog communities.

  15. Sequence stratigraphy and environmental background of the late Pleistocene and Holocene occupation in the Southeast Primor'ye (the Russian Far East)

    Science.gov (United States)

    Chlachula, Jiri; Krupyanko, Alexander A.

    2016-06-01

    The paper presents the results of Quaternary palaeoecology and geoarchaeology studies in the Zerkal'naya Basin, with new insights about sequenced natural shifts during the prehistoric occupation of this marginally explored NE Asian maritime territory. The Basin is part of the continental drainage system and the main physiographic and biotic corridor for peopling of the transitive coastal interior SE Primor'ye Region. The Final Pleistocene and Holocene environmental (biotic and abiotic) proxy records from the Upper/Final Palaeolithic to early historical sites document a dynamic climate change with vegetation cover transformations within riverine and mountain valley ecosystems of the Russian Far East. Most of the archaeological sites located on the low terraces and bedrock promontories along the main river channel and its tributary streams suggest traditional hunter gathered lifestyles based on seasonal salmon-fishing supplemented by pastoral economy. Tundra-forests with larch trees, dwarf birch thickets and polypod ferns from the basal stratigraphic units of the late Last Glacial occupation sites associated with the Upper Palaeolithic micro-blade and bifacial stone tool traditions (14C-dated to 19,000-12,000 cal yrs BP) indicate rather pronounced conditions and much lower MAT comparing today. Following a final Pleistocene cooling event, a major climate warming marked the onset of Holocene accompanied by a regional humidity increase promoting the formation of a mixed broadleaved-coniferous oak-dominant taiga, and culminating in the mid-Holocene Climatic Optimum. The appearance of mosaic parklands ca. 5,000-4,000 cal yrs BP. may be partly attributed to the expansion of the Far Eastern Neolithic cultures practicing forest clearance for pastures and dwellings. A progressing landscape opening indicated by the spread of light-demanding thickets and birch-dominated riverine biotopes with Artemisia suggests a further vegetation cover transformation during the late Neolithic

  16. REINTERPRETATION OF THE LATE PLEISTOCENE INGARANO CAVE DEPOSIT BASED ON THE FOSSIL BIRD ASSOCIATION (APULIA, SOUTH-EASTERN ITALY

    Directory of Open Access Journals (Sweden)

    CLAUDIA BEDETTI

    2007-11-01

    Full Text Available We present a study of Late Pleistocene fossil bird remains from Ingarano (Apulia, SE Italy, based on the revision of previously published material and the study of unpublished fossils bones. New field observations make it possible to simplify the stratigraphy of the deposit compared to previous work. The systematic study of the fossil bird bones revealed the presence of 15 taxa, including two hypothetical ones: Circus aeruginosus, Buteo rufinus, Aquila chrysaëtos, Falco columbarius, Falco cherrug, Alectoris graeca, Perdix perdix, Columba livia, Otus scops, Nyctea scandiaca, Nyctea scandiaca vel Bubo bubo, Athene noctua, Pyrrhocorax graculus, Pyrrhocorax pyrrhocorax, Corvus corone, Corvus corone vel Corvus frugilegus, Corvus corax. Our detailed study also helps improve the taphonomical interpretation of the deposit: the remains from the lower layers were accumulated after mammalian predator activity and were transported over short distances, while the ones from the upper layers show sings of intense transport, such as fractures and surface abrasion. Two different bird assemblages were recognized, respectively from the lowermost and the upper layers of the clastic succession exposed in the Ingarano deposit; this difference is also confirmed by the fossil mammal remains. The systematic study makes it possible to make palaeoenvironmental and palaeoclimatic reconstructions: both assemblages indicate open environments, and the taxa of the lower layers indicate the presence of woods and wetlands with colder characteristics, while birds of the upper layers indicate drier and warmer conditions. This analysis, and the dating established through geochemical analyses and study of lithic artefacts, lead us to date the formation of the Ingarano deposit to the Late Pleistocene, in particular to the MIS 3. The presence of a layer dated to the MIS 2 at the base of the succession indicated in previous works cannot be confirmed. 

  17. Late Pleistocene glacial stratigraphy of the Kumara-Moana region, West Coast of South Island, New Zealand

    Science.gov (United States)

    Barrows, Timothy T.; Almond, Peter; Rose, Robert; Keith Fifield, L.; Mills, Stephanie C.; Tims, Stephen G.

    2013-08-01

    On the South Island of New Zealand, large piedmont glaciers descended from an ice cap on the Southern Alps onto the coastal plain of the West Coast during the late Pleistocene. The series of moraine belts and outwash plains left by the Taramakau glacier are used as a type section for interpreting the glacial geology and timing of major climatic events of New Zealand and also as a benchmark for comparison with the wider Southern Hemisphere. In this paper we review the chronology of advances by the Taramakau glacier during the last or Otira Glaciation using a combination of exposure dating using the cosmogenic nuclides 10Be and 36Cl, and tephrochronology. We document three distinct glacial maxima, represented by the Loopline, Larrikins and Moana Formations, separated by brief interstadials. We find that the Loopline Formation, originally attributed to Oxygen Isotope Chronozone 4, is much younger than previously thought, with an advance culminating around 24,900 ± 800 yr. The widespread late Pleistocene Kawakawa/Oruanui tephra stratigraphically lies immediately above it. This Formation has the same age previously attributed to the older part of the Larrikins Formation. Dating of the Larrikins Formation demonstrates there is no longer a basis for subdividing it into older and younger phases with an advance lasting about 1000 years between 20,800 ± 500 to 20,000 ± 400 yr. The Moana Formation represents the deposits of the last major advance of ice at 17,300 ± 500 yr and is younger than expected based on limited previous dating. The timing of major piedmont glaciation is restricted to between ˜25,000 and 17,000 yr and this interval corresponds to a time of regionally cold sea surface temperatures, expansion of grasslands at the expense of forest on South Island, and hemisphere wide glaciation.

  18. The three-quarter power scaling of extinction risk in Late Pleistocene mammals, and a new theory of the size selectivity of extinction

    NARCIS (Netherlands)

    Polishchuk, L.

    2010-01-01

    Questions: What is the pattern of body mass versus extinction risk in the Late Pleistocene extinctions of mammals, both qualitatively and quantitatively? Are there patterns that relate extinction risk to the well-known allometries of body mass with population density or population growth rate?

  19. Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of southern California: Implications for understanding the paleoenvironment of the Late Pleistocene

    Science.gov (United States)

    The Rancho La Brea Tar Pits is the world’s richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironm...

  20. An Arctic perspective on dating Mid-Late Pleistocene environmental history

    DEFF Research Database (Denmark)

    Alexanderson, Helena; Backman, Jan; Cronin, Thomas M.

    2014-01-01

    we discuss, from an Arctic perspective, methods and correlation tools that are commonly used to date Arctic Pleistocene marine and terrestrial events. We review the state of the art of Arctic geochronology, with focus on factors that affect the possibility and quality of dating, and support...... this overview by examples of application of modern dating methods to Arctic terrestrial and marine sequences. Event stratigraphy and numerical ages are important tools used in the Arctic to correlate fragmented terrestrial records and to establish regional stratigraphic schemes. Age control is commonly provided...... of these proxies reveal cyclical patterns that provide a basis for astronomical tuning. Recent advances in dating technology, calibration and age modelling allow for measuring smaller quantities of material and to more precisely date previously undatable material (i.e. foraminifera for 14C, and single...

  1. Giant seismites and megablock uplift in the East African Rift: evidence for Late Pleistocene large magnitude earthquakes.

    Science.gov (United States)

    Hilbert-Wolf, Hannah Louise; Roberts, Eric M

    2015-01-01

    In lieu of comprehensive instrumental seismic monitoring, short historical records, and limited fault trench investigations for many seismically active areas, the sedimentary record provides important archives of seismicity in the form of preserved horizons of soft-sediment deformation features, termed seismites. Here we report on extensive seismites in the Late Quaternary-Recent (≤ ~ 28,000 years BP) alluvial and lacustrine strata of the Rukwa Rift Basin, a segment of the Western Branch of the East African Rift System. We document examples of the most highly deformed sediments in shallow, subsurface strata close to the regional capital of Mbeya, Tanzania. This includes a remarkable, clastic 'megablock complex' that preserves remobilized sediment below vertically displaced blocks of intact strata (megablocks), some in excess of 20 m-wide. Documentation of these seismites expands the database of seismogenic sedimentary structures, and attests to large magnitude, Late Pleistocene-Recent earthquakes along the Western Branch of the East African Rift System. Understanding how seismicity deforms near-surface sediments is critical for predicting and preparing for modern seismic hazards, especially along the East African Rift and other tectonically active, developing regions.

  2. A warm thermal enclave in the late Pleistocene of the south-eastern United States.

    Science.gov (United States)

    Russell, Dale A; Rich, Fredrick J; Schneider, Vincent; Lynch-Stieglitz, Jean

    2009-05-01

    Physical and biological evidence supports the probable existence of an enclave of relatively warm climate located between the Southern Appalachian Mountains and the Atlantic Ocean in the United States during the Last Glacial Maximum. The region supported a mosaic of forest and prairie habitats inhabited by a "Floridian" ice-age biota. Plant and vertebrate remains suggest an ecological gradient towards Cape Hatteras (35 degreesN) wherein forests tended to replace prairies, and browsing proboscideans tended to replace grazing proboscideans. Beyond 35 degreesN, warm waters of the Gulf Stream were deflected towards the central Atlantic, and a cold-facies biota replaced "Floridian" biota on the Atlantic coastal plain. Because of niche diversity and relatively benign climate, biodiversity may have been greater in the south-eastern thermal enclave than in other unglaciated areas of North America. However, the impact of terminal Pleistocene megafaunal extinctions may also have been shorter and more severe in the enclave than further north. A comparison with biotic changes that occurred in North America approximately 55 million years (ma) ago at the Paleocene-Eocene Thermal Maximum suggests that similar processes of change took place under both ice-house and greenhouse climates.

  3. Late Pleistocene Climate Events and The Origin of Agriculture In SW Asia

    Science.gov (United States)

    Rossignol-Strick, M.

    In the Eastern Mediterranean sea, the climate succession of the last deglaciation is documented and dated in marine cores by the d18-O variation of foraminiferal cal- cite and pollen records. The Last Glacial Maximum is identified by a large abundance of grass pollen from a prairie-type vegetal cover with low annual precipitation in the mountainous north and east borderlands of the sea, where the pollen mainly origi- nates. During the first phase of the last deglaciation, the Bolling/Allerod chronozone, the moisture availability increases and makes possible the spread of a deciduous for- est, as shown by the increasing pollen abundance of the deciduous oak. The cold and arid Younger Dryas is identified by a reversal to semi-desert conditions, with the in- crease of sage-brush (Artemisia) and the saline-tolerant Chenopodiaceae. The climate of the earliest Holocene is Optimum for at least 3000 years (9000-6000yr BP), with the largest spread of the deciduous forest at low-middle elevations signalling wet sum- mers and of the Pistacia woodland at low elevations signalling mild, no-frost winters. This is the time when the most recent sapropel deposited in the eastern Mediterranean under anoxic bottom conditions generated by a surface lid of lower salinity due to the concomitant largest floods of the Nile River fed by the strongest African monsoon rains in the Ethiopian Highlands. In SW Asia, the pollen records of lakes and marshes have been correlated with those of the marine cores, thereby obtaining a robust time-frame. In that area, the archaeo- logical data of human settlements are independently dated by 14C. Thus the archaeo- logical succession can be securely set against the well-dated climatic succession. The Late Palaeolithic populations of SW Asia were wandering hunter-gatherers in the prairies of the Last Glacial Maximum, where they already collected wild wheat, barley and fruit. With the Bolling/Allerod wetter and warmer climate, they began to settle in

  4. Two Late Pleistocene climate-driven incision/aggradation rhythms in the middle Dnieper River basin, west-central Russian Plain

    Science.gov (United States)

    Panin, Andrei; Adamiec, Grzegorz; Buylaert, Jan-Pieter; Matlakhova, Ekaterina; Moska, Piotr; Novenko, Elena

    2017-06-01

    In valleys of the River Seim and its tributaries in the middle Dnieper basin (west-central Russian Plain), two low terraces (T1, 10-16 m, and T0, 5-7 m above the river) and a floodplain (2-4 m) with characteristic large and small palaeochannels exist. A range of field and laboratory techniques was applied and ∼30 new numerical ages (OSL and 14C dates) were obtained to establish a chronology of incision and aggradation events that resulted in the current valley morphology. Two full incision/aggradation rhythms and one additional aggradation phase from the previous rhythm were recognized in the Late Pleistocene - Holocene climate cycle. The following events were detected. (1) Late MIS 5 - early MIS 4: aggradation of Terrace T1 following the deep incision at the end of MIS 6. (2) Late MIS 4 (40-30 ka): incision into Terrace T1 below the present-day river, formation of the main scarp in the bottom of the valley between Terrace T1 and Terrace T0/Floodplain levels. (3) MIS 2: aggradation of Terrace T0, lateral migrations of a shallow braided channel located few meters above the present-day river since ∼25 ka through the LGM. (4) 18-13 ka: incision into Terrace T0 below the modern river. Multiple-thread channels concentrated in a single flow that at some places formed large meanders. In the period 15-13 ka, high floods that rose above the present-day floods left large levees and overbank loams on Terrace T0. (5) Younger Dryas - Holocene transition: aggradation up to the modern channel level, transformation of large Late Glacial to small Holocene meanders. The established incision/aggradation rhythms are believed to be manifested over the Central Russian Plain outside the influence of ice sheets in the north and base level changes in the south. The two-phase deepening of the valley occurred in the last quarter of the last glacial epoch but can not be attributed directly to the glacial-interglacial transition. Both the detected incision events correspond to relatively

  5. Late Pleistocene Age Model for Site U1460, Perth Basin, SW Australian Shelf: Implications for Leeuwin Current History

    Science.gov (United States)

    Christensen, B. A.; Takayanagi, H.; Petrick, B.; Ishiwa, T.; Henderiks, J.; Groeneveld, J.; Mamo, B. L.; De Vleeschouwer, D.; Auer, G.; Deik, H.; Fulthorpe, C.; Gallagher, S. J.; McHugh, C.; Reuning, L.; Yokoyama, Y.

    2017-12-01

    The Leeuwin Current (LC) exerts an important control on modern Australian climate, but its onset is not well defined. The LC is the only southward flowing eastern boundary current. Driven by a pressure gradient set up in the Indonesian Throughflow, its warm waters support reefs to 29°S. It is seasonally controlled south of the Western Cape. Determination of the onset of the LC was a major objective of IODP Expedition 356. Expedition 356 drilling on the western Australian margin provides an opportunity to explore depositional patterns and timing in the region influenced by the current. Site U1460 was drilled in 214.5 m w.d. (Gallagher et al., 2017). Integrated calcareous nannofossil and planktonic foraminiferal biostratigraphy places the upper 86.5 m firmly within the late Pleistocene. However, the glacial- interglacial stratigraphy is uncertain because of the complexity of this shelfal depositional environment. Here we present a likely late Pleistocene stratigraphy based on integrated geochemical and paleontological datasets. A benthic foraminifer (Uvigerina peregrina) stable isotope record provides the foundation for the age model and the data are supported by SST estimates based on Tex86 and alkenones. Our age model places MIS 16 between 104 and 99 m-CSF-A, followed by an expanded MIS 15 section (99 - 50 m-CSF-A). We correlate the interval from 50 - 5 m-CSF-A with MIS 14 to MIS 8, with the largest magnitude glacial events (MIS 12, MIS 6) either condensed or represented as depositional hiatuses. A Recent 14C date at 0.34 mbsf constrains the interval from 2 - 0.5 m-CSF-A to MIS 4-3, which is in good agreement with the base of common Emiliania huxleyi (0.09 Ma) at 2.13 m-CSF-A. Thus MIS 5 is equivalent to the interval from 5 to 2 m-CSF-A. The expanded MIS 15 section follows a geometric change from slope to prograding shelf. It is associated with a shift to infaunal benthic foraminiferal assemblages, abundant sponge spicules, and a reduction in CaCO3%, suggesting

  6. A Late Pleistocene linear dune dam record of aeolian-fluvial dynamics at the fringes of the northwestern Negev dunefield

    Science.gov (United States)

    Roskin, Joel; Bookman, Revital; Friesem, David; Vardi, Jacob

    2017-04-01

    The paper presents a late Pleistocene aeolian-fluvial record within a linear dune-like structure that partway served as a dune dam. Situated along the southern fringe of the northwestern Negev desert dunefield (Israel) the structure's morphology, orientation, and some of its stratigraphic units partly resemble adjacent west-east extending vegetated linear dunes. Uneven levels of light-colored, fine-grained fluvial deposits (LFFDs) extend to the north and south from the flanks of the studied structure. Abundant Epipalaeolithic sites line the fringes of the LFFDs. The LFFD microstructures of fine graded bedding and clay blocky peds indicate sorting and shrinking of saturated clays in transitional environments between low energy flows to shallow standing water formed by dunes damming a mid-sized drainage system. The structure's architecture of interchanging units of sand with LFFDs indicates interchanging dominances between aeolian sand incursion and winter floods. Sand mobilization associated with powerful winds during the Heinrich 1 event led to dune damming downstream of the structure and within the structure to in-situ sand deposition, partial fluvial erosion, reworking of the sand, and LFFD deposition. Increased sand deposition led to structure growth and blockage of its drainage system that in turn accumulated LFFD units up stream of the structure. Extrapolation of current local fluvial sediment yields indicate that LFFD accretion up to the structure's brim occurred over a short period of several decades. Thin layers of Geometric Kebaran (c. 17.5-14.5 ka cal BP) to Harifian (12-11 ka BP) artifacts within the structure's surface indicates intermittent, repetitive, and short term camping utilizing adjacent water along a timespan of 4-6 kyr. The finds directly imply that the NW Negev LFFDs formed in dune-dammed water bodies which themselves were formed following events of vegetated linear dune elongation. LFFD accumulation persisted as a result of dune dam

  7. Depositional Architecture of Late Pleistocene-Holocene Coastal Alluvial-fan System in the Coastal Range, Taiwan

    Science.gov (United States)

    Chen, S. T.; Chen, W. S.

    2016-12-01

    Since late Pleistocene, the Coastal Range (Philippine Sea plate) collided and overridden on the Central Range (Eurasian Plate) along the Longitudinal Valley Fault. Therefore, the Coastal Range is exposed widely the late Pleistocene-Holocene marine and fluvial terraces caused by the tectonic uplift. Based on the estimation of paleosea-level elevations (Δh), depositional paleodepth, altitude distribution of Holocene deposits (D), altitude of outcrops (H), and 14C dating of marine deposits (t), the uplift rate (=(Δh+H +d-D)/t) is about 5-10 mm/yr in the southern Coastal Range. In this study, we suggest through field logging that the deposits can be divided into alluvial, foreshore (intertidal), shoreface, and offshore environments. In Dulan area in the southern Coastal Range, the uplift rate was 6-7 mm/yr during 16,380-10,000 cal yr BP and 3-4 mm/yr after 7,000 cal yr BP. Results from the Dulan Coastal alluvial-fan system can be divided into five depositional stages: (1) 16,380-14,300 cal yr BP: The rate of global sea level rise (SLR) has averaged about 6-7 mm/yr, similar to the tectonic uplift rate. In this stage, the bedrock was eroded and formed a wide wave-cut platform. (2) 14,300-10,000 cal yr BP: SLR of about 14 mm/yr that was faster than tectonic uplift rate of 6-7 mm/yr. As a result of transgression, the beach-lagoon deposits about 5 m thick were unconformably overlain on the wave-cut platform. (3) 10,000-8,200 cal yr BP: The ongoing sea level rise (SLR: 11 mm/yr), the lagoon deposits were overlain by an offshore slump deposits representing a gradual deepening of the depositional environment. (4) 8,200-7,930 cal yr BP (SLR: 6-7 mm/yr): The tectonic uplift rate may occur at similar SLR. The alluvial-fan deposits have prograded over the shallow marine deposits. (5) After 7,000 cal yr BP (SLR: 1-0 mm/yr): SLR was much slower than tectonic uplift rate of 3-4 mm/yr. Thus, Holocene marine terraces are extensively developed in the coastal region, showing that the

  8. Distribution of late Pleistocene ice-rich syngenetic permafrost of the Yedoma Suite in east and central Siberia, Russia

    Science.gov (United States)

    Grosse, Guido; Robinson, Joel E.; Bryant, Robin; Taylor, Maxwell D.; Harper, William; DeMasi, Amy; Kyker-Snowman, Emily; Veremeeva, Alexandra; Schirrmeister, Lutz; Harden, Jennifer

    2013-01-01

    This digital database is the product of collaboration between the U.S. Geological Survey, the Geophysical Institute at the University of Alaska, Fairbanks; the Los Altos Hills Foothill College GeoSpatial Technology Certificate Program; the Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany; and the Institute of Physical Chemical and Biological Problems in Soil Science of the Russian Academy of Sciences. The primary goal for creating this digital database is to enhance current estimates of soil organic carbon stored in deep permafrost, in particular the late Pleistocene syngenetic ice-rich permafrost deposits of the Yedoma Suite. Previous studies estimated that Yedoma deposits cover about 1 million square kilometers of a large region in central and eastern Siberia, but these estimates generally are based on maps with scales smaller than 1:10,000,000. Taking into account this large area, it was estimated that Yedoma may store as much as 500 petagrams of soil organic carbon, a large part of which is vulnerable to thaw and mobilization from thermokarst and erosion. To refine assessments of the spatial distribution of Yedoma deposits, we digitized 11 Russian Quaternary geologic maps. Our study focused on extracting geologic units interpreted by us as late Pleistocene ice-rich syngenetic Yedoma deposits based on lithology, ground ice conditions, stratigraphy, and geomorphological and spatial association. These Yedoma units then were merged into a single data layer across map tiles. The spatial database provides a useful update of the spatial distribution of this deposit for an approximately 2.32 million square kilometers land area in Siberia that will (1) serve as a core database for future refinements of Yedoma distribution in additional regions, and (2) provide a starting point to revise the size of deep but thaw-vulnerable permafrost carbon pools in the Arctic based on surface geology and the distribution of cryolithofacies types at high spatial

  9. Postprandial dysmetabolism: Too early or too late?

    Science.gov (United States)

    Pappas, Christos; Kandaraki, Eleni A; Tsirona, Sofia; Kountouras, Dimitrios; Kassi, Georgia; Diamanti-Kandarakis, Evanthia

    2016-07-01

    Postprandial dysmetabolism is a postprandial state characterized by abnormal metabolism of glucose and lipids and, more specifically, of elevated levels of glucose and triglyceride (TG) containing lipoproteins. Since there is evidence that postprandial dysmetabolism is associated with increased cardiovascular mortality and morbidity, due to macro- and microvascular complications, as well as with conditions such as polycystic ovary syndrome (PCOS) and non-alcoholic fatty liver disease (NAFLD), it is recommended that clinicians be alert for early detection and management of this condition. Management consists of a holistic approach including dietary modification, exercise and use of hypoglycemic and hypolipidemic medication aiming to decrease the postprandial values of circulating glucose and triglycerides. This review aims to explain glucose and lipid homeostasis and the impact of postprandial dysmetabolism on the cardiovascular system as well as to offer suggestions with regard to the therapeutic approach for this entity. However, more trials are required to prevent or reverse early and not too late the actual tissue damage due to postprandial dysmetabolism.

  10. Reconstructing Early Pleistocene (1.3 Ma) terrestrial environmental change in western Anatolia: Did it drive fluvial terrace formation?

    NARCIS (Netherlands)

    Veldkamp, A.; Candy, I.; Jongmans, A.G.; Maddy, D.; Demir, T.; Schoorl, J.M.; Schreve, D.; Stemerdink, C.; Schriek, van der T.

    2015-01-01

    A terrestrial environmental reconstruction of an Early Pleistocene landscape from western Anatolia is presented. The basis of this reconstruction is a sedimentary stack comprising fluvial and colluvial slope deposits. Contained within this stack is a sequence comprising two massive laminar calcretes

  11. Land-sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    NARCIS (Netherlands)

    Donders, Timme; Van Helmond, Niels A.G.M.; Verreussel, Roel; Munsterman, Dirk; Veen, Johan Ten; Speijer, Robert P.; Weijers, Johan W.H.; Sangiorgi, Francesca; Peterse, Francien; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.; Lourens, Lucas; Kuhlmann, Gesa; Brinkhuis, Henk

    2018-01-01

    We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (ĝ1/4 2.6-1.8ĝ€Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of

  12. Reconstructing the migration patterns of late Pleistocene mammals from northern Florida, USA

    Science.gov (United States)

    Hoppe, Kathryn A.; Koch, Paul L.

    2007-11-01

    We used analyses of the strontium isotope ( 87Sr/ 86Sr) ratios of tooth enamel to reconstruct the migration patterns of fossil mammals collected along the Aucilla River in northern Florida. Specimens date to the late-glacial period and before the last glacial maximum (pre-LGM). Deer and tapir displayed low 87Sr/ 86Sr ratios that were similar to the ratios of Florida environments, which suggest that these taxa did not migrate long distance outside of the Florida region. Mastodons, mammoths, and equids all displayed a wide range of 87Sr/ 86Sr ratios. Some individuals in each taxon displayed low 87Sr/ 86Sr ratios that suggest they ranged locally, while other animals had high 87Sr/ 86Sr ratios that suggest they migrated long distances (> 150 km) outside of the Florida region. Mastodons were the only taxa from this region that provided enough well-dated specimens to compare changes in migration patterns over time. Pre-LGM mastodons displayed significantly lower 87Sr/ 86Sr ratios than late-glacial mastodons, which suggests that late-glacial mastodons from Florida migrated longer distances than their earlier counterparts. This change in movement patterns reflects temporal changes in regional vegetation patterns.

  13. Replicating the Ice-Volume Signal of the Early Pleistocene with a Complex Earth System Model

    Science.gov (United States)

    Tabor, C. R.; Poulsen, C. J.; Pollard, D.

    2013-12-01

    Milankovitch theory proposes high-latitude summer insolation intensity paces the ice ages by controlling perennial snow cover amounts (Milankovitch, 1941). According to theory, the ~21 kyr cycle of precession should dominate the ice-volume records since it has the greatest influence on high-latitude summer insolation. Modeling experiments frequently support Milankovitch theory by attributing the majority of Northern Hemisphere high-latitude summer snowmelt to changes in the cycle of precession (e.g. Jackson and Broccoli, 2003). However, ice-volume proxy records, especially those of the Early Pleistocene (2.6-0.8 Ma), display variability with a period of ~41 kyr (Raymo and Lisiecki, 2005), indicative of insolation forcing from obliquity, which has a much smaller influence on summer insolation intensity than precession. Several hypotheses attempt to explain the discrepancies between Milkankovitch theory and the proxy records by invoking phenomena such as insolation gradients (Raymo and Nisancioglu, 2003), hemispheric offset (Raymo et al., 2006; Lee and Poulsen, 2009), and integrated summer energy (Huybers, 2006); however, all of these hypotheses contain caveats (Ruddiman, 2006) and have yet to be supported by modeling studies that use a complex GCM. To explore potential solutions to this '41 kyr problem,' we use an Earth system model composed of the GENESIS GCM and Land Surface model, the BIOME4 vegetation model, and the Pennsylvania State ice-sheet model. Using an asynchronous coupling technique, we run four idealized transient combinations of obliquity and precession, representing the orbital extremes of the Pleistocene (Berger and Loutre, 1991). Each experiment is run through several complete orbital cycles with a dynamic ice domain spanning North America and Greenland, and fixed preindustrial greenhouse-gas concentrations. For all orbital configurations, model results produce greater ice-volume spectral power at the frequency of obliquity despite significantly

  14. A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient

    Directory of Open Access Journals (Sweden)

    L. E. Lisiecki

    2010-05-01

    Full Text Available The fact that the deep-ocean benthic δ13C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in Southern Ocean overturning. This study re-evaluates the implications of changes in benthic δ13C gradients by comparing Pacific Deep Water (PDW δ13C measurements with the values expected for the null hypothesis that PDW ventilation sources remained unchanged throughout the Late Pleistocene. The δ13C compositions of PDW, Northern Component Water (NCW and Southern Component Water (SCW are estimated from regional benthic δ13C stacks of 3–6 sites. Changes in PDW δ13C and PDW-SCW δ13C gradients over the past 800 kyr are found to be well described by a constant mixture of 60% NCW and 40% SCW plus a constant Pacific remineralization offset of −0.5‰. Thus, a change in PDW ventilation cannot be inferred solely on the basis of changes in the Pacific-South Atlantic benthic δ13C gradient.

  15. Conceptual hydrochemical model of late Pleistocene aquifers at the Samario-Sitio Grande petroleum reservoir, Gulf of Mexico, Mexico

    International Nuclear Information System (INIS)

    Birkle, Peter; Angulo, Maricela

    2005-01-01

    Carbon-14 concentrations between 0.83 and 11.79 pmC of formation water from the Activo Samaria-Sitio Grande petroleum reservoir in SE-Mexico, extracted from 3500 to 4500 m.b.s.l., indicate a common infiltration event of surface water during the late Pleistocene period. Mixing of two components - meteoric water and seawater, previously evaporated at the surface - explain the widespread mineralization (TDI = 15-257 g/L) of Na-Cl and Na-Ca-Cl type reservoir water. Statistical discrimination by clustering and a heterogeneous chemical-isotopic fluid composition indicate the existence of 4 different water types as part of local aquifer systems, which are separated by normal and thrust faults. Tectonic horst and graben structures show an ambiguous, individual hydraulic behaviour - as permeable conduits and/or as impermeable barriers, causing the local limitation of aquifer extent. The recent increase of water production in petroleum wells is not related to the injection of surface water, but the long-term extraction of oil reserves is modifying the original position and flow direction of the reservoir aquifers. The rise of the initial groundwater level reflects the final stage of an exhausted petroleum reservoir with coning effects of underlying aquifer systems. The flexible change towards superior production intervals could represent a feasible technique to avoid the abrupt closure of invaded production wells

  16. The role of cryptotephra in refining the chronology of Late Pleistocene human evolution and cultural change in North Africa

    Science.gov (United States)

    Barton, R. N. E.; Lane, C. S.; Albert, P. G.; White, D.; Collcutt, S. N.; Bouzouggar, A.; Ditchfield, P.; Farr, L.; Oh, A.; Ottolini, L.; Smith, V. C.; Van Peer, P.; Kindermann, K.

    2015-06-01

    Sites in North Africa hold key information for dating the presence of Homo sapiens and the distribution of Middle Stone Age (MSA), Middle Palaeolithic (MP) and Later Stone Age (LSA) cultural activity in the Late Pleistocene. Here we present new and review recently published tephrochronological evidence for five cave sites in North Africa with long MSA/MP and LSA cultural sequences. Four tephra horizons have been identified at the Haua Fteah (Cyrenaica, Libya). They include cryptotephra evidence for the Campanian Ignimbrite (CI) eruption dating to ˜39 ka that allows correlation with other Palaeolithic sequences in the eastern Mediterranean and as far north as Russia. Cryptotephra have also been recorded from the Moroccan sites of Taforalt, Rhafas and Dar es-Soltane 1. At Taforalt the geochemical composition suggests a provenance in the Azores, while examples from Sodmein (Egypt) appear to derive from central Anatolia and another unknown source. In these latter examples chemical compositional data from relevant proximal volcanic centres is currently lacking so the identification of tephra in layers of known age and cultural association provides the first reliable age determinations for distal volcanic events and their geographical extent. The future potential for tephrochronological research in North Africa is also discussed.

  17. Conceptual hydrochemical model of late Pleistocene aquifers at the Samario-Sitio Grande petroleum reservoir, Gulf of Mexico, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Birkle, Peter [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Av. Reforma 113, Col. Palmira, Cuernavaca, Mor., 62490 (Mexico)]. E-mail: birkle@iie.org.mx; Angulo, Maricela [PEMEX - Exploracion y Produccion, Diseno de Explotacion Cactus-Nispero Sitio Grande, Zona Industrial S/N, Reforma, Chiapas (Mexico)

    2005-06-15

    Carbon-14 concentrations between 0.83 and 11.79 pmC of formation water from the Activo Samaria-Sitio Grande petroleum reservoir in SE-Mexico, extracted from 3500 to 4500 m.b.s.l., indicate a common infiltration event of surface water during the late Pleistocene period. Mixing of two components - meteoric water and seawater, previously evaporated at the surface - explain the widespread mineralization (TDI = 15-257 g/L) of Na-Cl and Na-Ca-Cl type reservoir water. Statistical discrimination by clustering and a heterogeneous chemical-isotopic fluid composition indicate the existence of 4 different water types as part of local aquifer systems, which are separated by normal and thrust faults. Tectonic horst and graben structures show an ambiguous, individual hydraulic behaviour - as permeable conduits and/or as impermeable barriers, causing the local limitation of aquifer extent. The recent increase of water production in petroleum wells is not related to the injection of surface water, but the long-term extraction of oil reserves is modifying the original position and flow direction of the reservoir aquifers. The rise of the initial groundwater level reflects the final stage of an exhausted petroleum reservoir with coning effects of underlying aquifer systems. The flexible change towards superior production intervals could represent a feasible technique to avoid the abrupt closure of invaded production wells.

  18. Across the Gap: Geochronological and Sedimentological Analyses from the Late Pleistocene-Holocene Sequence of Goda Buticha, Southeastern Ethiopia

    Science.gov (United States)

    Asrat, Asfawossen; Bahain, Jean-Jacques; Chapon, Cécile; Douville, Eric; Fragnol, Carole; Hernandez, Marion; Hovers, Erella; Leplongeon, Alice; Martin, Loïc; Pleurdeau, David; Pearson, Osbjorn; Puaud, Simon; Assefa, Zelalem

    2017-01-01

    Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications of these observations, sedimentological analyses combined with optically stimulated luminescence (OSL) were conducted. The OSL data now extend the radiocarbon chronology up to 63 ± 7 ka; they also confirm the existence of the chronological gap between 24.8 ± 2.6 ka and 7.5 ± 0.3 ka. The sedimentological analyses suggest that the origin and mode of deposition were largely similar throughout the whole sequence, although the anthropic and faunal activities increased in the younger levels. Regional climatic records are used to support the sedimentological observations and interpretations. We discuss the implications of the sedimentological and dating analyses for understanding cultural processes in the region. PMID:28125597

  19. Compton Composites Late in the Early Universe

    Directory of Open Access Journals (Sweden)

    Frederick Mayer

    2014-07-01

    Full Text Available Beginning roughly two hundred years after the big-bang, a tresino phase transition generated Compton-scale composite particles and converted most of the ordinary plasma baryons into new forms of dark matter. Our model consists of ordinary electrons and protons that have been bound into mostly undetectable forms. This picture provides an explanation of the composition and history of ordinary to dark matter conversion starting with, and maintaining, a critical density Universe. The tresino phase transition started the conversion of ordinary matter plasma into tresino-proton pairs prior to the the recombination era. We derive the appropriate Saha–Boltzmann equilibrium to determine the plasma composition throughout the phase transition and later. The baryon population is shown to be quickly modified from ordinary matter plasma prior to the transition to a small amount of ordinary matter and a much larger amount of dark matter after the transition. We describe the tresino phase transition and the origin, quantity and evolution of the dark matter as it takes place from late in the early Universe until the present.

  20. Uranium/thorium dating of late Pleistocene peat deposits in N.W. Europe.

    NARCIS (Netherlands)

    Heijnis, Hendrik

    1992-01-01

    Dating of peat by means of uranium series disequilibrium (230-Th/234-U, also known as UTD) with special emphasis on dating the early Weichselian interstadial and last interglacial peats in north western Europe, is the subject of this study. ... Zie: Introduction

  1. Pollen evidence for late pleistocene bering land bridge environments from Norton Sound, Northeastern Bering Sea, Alaska

    Science.gov (United States)

    Ager, T.A.; Phillips, R.L.

    2008-01-01

    After more than half a century of paleoenvironmental investigations, disagreements persist as to the nature of vegetation type and climate of the Bering land bridge (BLB) during the late Wisconsin (Sartan) glacial interval. Few data exist from sites on the former land bridge, now submerged under the Bering and Chukchi Seas. Two hypotheses have emerged during the past decade. The first, based on pollen data from Bering Sea islands and adjacent mainlands of western Alaska and Northeast Siberia, represents the likely predominant vegetation on the Bering land bridge during full-glacial conditions: graminoid-herb-willow tundra vegetation associated with cold, dry winters and cool, dry summer climate. The second hypothesis suggests that dwarf birch-shrub-herb tundra formed a broad belt across the BLB, and that mesic vegetation was associated with cold, snowier winters and moist, cool summers. As a step towards resolving this controversy, a sediment core from Norton Sound, northeastern Bering Sea was radiocarbon dated and analyzed for pollen content. Two pollen zones were identified. The older, bracketed by radiocarbon ages of 29,500 and 11,515 14C yr BP, contains pollen assemblages composed of grass, sedge, wormwood, willow, and a variety of herb (forb) taxa. These assemblages are interpreted to represent graminoid-herb-willow tundra vegetation that developed under an arid, cool climate regime. The younger pollen zone sediments were deposited about 11,515 14C yr BP, when rising sea level had begun to flood the BLB. This younger pollen zone contains pollen of birch, willow, heaths, aquatic plants, and spores of sphagnum moss. This is interpreted to represent a Lateglacial dwarf birch-heath-willow-herb tundra vegetation, likely associated with a wetter climate with deeper winter snows, and moist, cool summers. This record supports the first hypothesis, that graminoid-herb-willow tundra vegetation extended into the lowlands of the BLB during full glacial conditions of the

  2. The late Pleistocene to Holocene palaeogeographic evolution of the Porto Conte area: Clues for a better understanding of human colonization of Sardinia and faunal dynamics during the last 30 ka

    NARCIS (Netherlands)

    Palombo, M.R.; Antonioli, F.; Lo Presti, V.; Mannino, M.A.; Melis, R.T.; Orru, P.; Stocchi, P.; Talamo, S.; Quarta, G.; Calcagnile, L.; Deiana, G.; Altamura, S.

    2017-01-01

    The timing of the colonization of Sardinia by mammalian fauna and anatomically modern humans (AMH) is currently under debate. The understanding of the geological and palaeoclimatological conditions that characterized the Late Pleistocene and the Holocene is essential to investigate colonization

  3. Long-term climate record inferred from early-middle Pleistocene amphibian and squamate reptile assemblages at the Gran Dolina Cave, Atapuerca, Spain.

    Science.gov (United States)

    Blain, Hugues-Alexandre; Bailon, Salvador; Cuenca-Bescós, Gloria; Arsuaga, Juan Luis; Bermúdez de Castro, José Maria; Carbonell, Eudald

    2009-01-01

    The Gran Dolina cave site is famous for having delivered some of the oldest hominin remains of Western Europe (Homo antecessor, ca. 960 ka). Moreover, the evidence of lithic industries throughout the long vertical section suggests occupation on the part of hominins from the latest early Pleistocene (levels TD3/4, TD5, and TD6) to the late middle Pleistocene (level TD10). The Gran Dolina Sondeo Sur (TDS) has furnished a great number of small-vertebrate remains; among them some 40,000 bones are attributed to amphibians and squamates. Although they do not differ specifically from the extant herpetofauna of the Iberian Peninsula, the overlap of their current distribution areas (= mutual climatic range method) in Spain can provide mean annual temperatures (MAT), the mean temperatures of the coldest (MTC) and warmest (MTW) months, and mean annual precipitation (MAP) estimations for each sub-level, and their change can be studied throughout the sequence. Results from the squamate and amphibian study indicate that during hominin occupation the MAT (10-13 degrees C) was always slightly warmer than at present in the vicinity of the Gran Dolina Cave, and the MAP (800-1000mm) was greater than today in the Burgos area. Climatic differences between "glacial" and "interglacial" phases are poorly marked. Summer temperatures (MTW) show stronger oscillations than winter temperatures (MTC), but seasonality remains almost unchanged throughout the sequence. These results are compared with those for large mammals, small mammals, and pollen analysis, giving a scenario for the palaeoclimatic conditions that occurred during the early to middle Pleistocene in Atapuerca, and hence a scenario for the hominins that once lived in the Sierra de Atapuerca.

  4. Evidence for Late Pleistocene uplift at the Somma-Vesuvius apron near Pompeii

    Science.gov (United States)

    Marturano, Aldo; Aiello, Giuseppe; Barra, Diana

    2011-05-01

    Detailed stratigraphic and micropalaeontological analyses of samples from boreholes at the Somma-Vesuvius apron, between Pompeii and the sea, allowed reconstruction of Late Quaternary palaeoenvironmental evolution of the Sarno coastal plain. In all, 116 samples were recovered from seven boreholes drilled from 2-10 m a.s.l. to 16.5-26 m b.s.l. Microfossil assemblages, with special regard to benthic foraminifers and ostracods, were used to reconstruct the depositional palaeoenvironment. Fossil remains show that all the pre-79 AD fossiliferous sediments from 2 to - 24 m a.s.l. were deposited in shallow marine waters for a long time despite an appreciable sea level rise. The data indicate alternation of both shallow marine and subaerial conditions during the last ~ 15 kyr, evidencing ground uplift of the area of about 75 m at a rate of ~ 5 mm/year. Marine sediment accumulation (~ 6 m/kyr) and tectonic uplift long offset the sea level rise, and as a consequence, submerged areas remained the same as well.

  5. The Early vs. Late Infantile Strabismus Surgery Study: Monitoring Report

    NARCIS (Netherlands)

    H.J. Simonsz (Huib)

    1995-01-01

    textabstractAbstract: The Early vs. Late Infantile Strabismus Surgery Study Group is a group of strabismologists and orthoptists who investigate whether early or late surgery is preferable in infantile strabismus, in a non-randomized, prospective, multi-center trial. Infants between six and 18

  6. Ancient inland human dispersals from Myanmar into interior East Asia since the Late Pleistocene.

    Science.gov (United States)

    Li, Yu-Chun; Wang, Hua-Wei; Tian, Jiao-Yang; Liu, Li-Na; Yang, Li-Qin; Zhu, Chun-Ling; Wu, Shi-Fang; Kong, Qing-Peng; Zhang, Ya-Ping

    2015-03-26

    Given the existence of plenty of river valleys connecting Southeast and East Asia, it is possible that some inland route(s) might have been adopted by the initial settlers to migrate into the interior of East Asia. Here we analyzed mitochondrial DNA (mtDNA) HVS variants of 845 newly collected individuals from 14 Myanmar populations and 5,907 published individuals from 115 populations from Myanmar and its surroundings. Enrichment of basal lineages with the highest genetic diversity in Myanmar suggests that Myanmar was likely one of the differentiation centers of the early modern humans. Intriguingly, some haplogroups were shared merely between Myanmar and southwestern China, hinting certain genetic connection between both regions. Further analyses revealed that such connection was in fact attributed to both recent gene flow and certain ancient dispersals from Myanmar to southwestern China during 25-10 kya, suggesting that, besides the coastal route, the early modern humans also adopted an inland dispersal route to populate the interior of East Asia.

  7. Parapneumonic pleural effusion: early versus late thoracoscopy

    Directory of Open Access Journals (Sweden)

    Rodrigo Romualdo Pereira

    2017-07-01

    Full Text Available ABSTRACT Objective: To evaluate the best time to perform thoracoscopy for the treatment of complicated parapneumonic pleural effusion in the fibrinopurulent phase in patients ≤ 14 years of age, regarding the postoperative evolution and occurrence of complications. Methods: This was a retrospective comparative study involving patients with parapneumonic pleural effusion presenting with septations or loculations on chest ultrasound who underwent thoracoscopy between January of 2000 and January of 2013. The patients were divided into two groups: early thoracoscopy (ET, performed by day 5 of hospitalization; and late thoracoscopy (LT, performed after day 5 of hospitalization. Results: We included 60 patients, 30 in each group. The mean age was 3.4 years; 28 patients (46.7% were male; and 47 (78.3% underwent primary thoracoscopy (no previous simple drainage. The two groups were similar regarding gender, age, weight, and type of thoracoscopy (p > 0.05 for all. There was a significant difference between the ET and the LT groups regarding the length of the hospital stay (14.5 days vs. 21.7 days; p < 0.001. There were also significant differences between the groups regarding the duration of fever in days; the total number of days from admission to the initiation of drainage; and the total number of days with the drain in place. Eight patients (13.6% had at least one post-thoracoscopy complication, there being no difference between the groups. There were no deaths. Conclusions: Performing ET by day 5 of hospitalization was associated with shorter hospital stays, shorter duration of drainage, and shorter duration of fever, although not with a higher frequency of complications, requiring ICU admission, or requiring blood transfusion.

  8. Glacial chronology and palaeoclimate in the Bystra catchment, Western Tatra Mountains (Poland) during the Late Pleistocene

    Science.gov (United States)

    Makos, Michał; Rinterknecht, Vincent; Braucher, Régis; Żarnowski, Michał

    2016-02-01

    Deglaciation chronology of the Bystra catchment (Western Tatra Mountains) has been reconstructed based on 10Be exposure age dating. Fourteen rock samples were collected from boulders located on three moraines that limit the horizontal extent of the LGM maximum advance and the Lateglacial recessional stage. The oldest preserved, maximum moraine was dated at 15.5 ± 0.8 ka, an age that could be explained more likely by post-depositional erosion of the moraine. Such scenario is supported by geomorphologic and palaeoclimatological evidence. The younger cold stage is represented by well-preserved termino-lateral moraine systems in the Kondratowa and Sucha Kasprowa valleys. The distribution of the moraine ridges in both valleys suggest a complex history of deglaciation of the area. The first Late-glacial re-advance (LG1) was followed by a cold oscillation (LG2), that occurred at around 14.0 ± 0.7-13.7 ± 1.2 ka. Glaciers during both stages had nearly the same horizontal extent, however, their thickness and geometry changed significantly, mainly due to local climatic conditions triggered by topography, controlling the exposition to solar radiation. The LG1 stage occurred probably during the pre-Bølling cold stage (Greenland Stadial 2.1a), however, the LG2 stage can be correlated with the cooling at around 14 ka during the Greenland Interstadial 1 (GI-1d - Older Dryas). This is the first chronological evidence of the Older Dryas in the Tatra Mountains. The ELA of the maximum Bystra glacier was located at 1480 m a.s.l. in accordance with the ELA in the High Tatra Mountains during the LGM. During the LG1 and LG2 stages, the ELA in the catchment rose up to 1520-1530 m a.s.l. and was located approximately 100-150 m lower than in the eastern part of the massif. Climate modelling results show that the Bystra glacier (maximum advance) could have advanced in the catchment when mean annual temperature was lower than today by 11-12 °C and precipitation was reduced by 40-60%. This

  9. Sedimentary Evolution of Marginal Ganga Foreland Basin during the Late Pleistocene

    Science.gov (United States)

    Ghosh, R.; Srivastava, P.; Shukla, U. K.

    2017-12-01

    Ganga foreland basin, an asymmetrical basin, was formed as result of plate-plate collision during middle Miocene. A major thrust event occurred during 500 ka when upper Siwalik sediments were uplifted and the modern Ganga foreland basin shifted towards craton, making a more wide and deep basin. The more distal part of this basin, south of axial river Yamuna, records fluvial sedimentary packages that helps to understand dynamics of peripheral bulge during the late Quaternary. Sedimentary architecture in conjunction with chemical index of alteration (CIA), paleocurrent direction and optically stimulated dating (OSL) from 19 stratigraphic sections helped reconstructing the variations in depositional environments vis-à-vis climate change and peripheral bulge tectonics. Three major units (i) paleosol; (ii) cratonic gravel; (iii) interfluve succession were identified. The lower unit-I showing CIA values close to 70-80 and micro-morphological features of moderately well-developed pedogenic unit that shows development of calcrete, rhizoliths, and mineralized organic matter in abundance. This is a regional paleosols unit and OSL age bracketed 200 ka. This is unconformably overlain by unit-II, a channelized gravel composed of sub-angular to sub-rounded clasts of granite, quartz, quartzite, limestone and calcrete. The gravel have low CIA value up to 55, rich in vertebrate fossil assemblages and mean paleocurrent vector direction is NE, which suggesting deposition by a fan of a river draining craton into foreland. This unit is dated between 100 ka and 54 ka. The top unit-III, interfluve succession of 10-15 m thick is composed of dark and light bands of sheet like deposit of silty clay to clayey silt comprises sand lenses of red to grey color and displaying top most OSL age is 12 ka. The basal mature paleosol signifies a humid climate developed under low subsidence rate at >100 ka. After a hiatus represented by pedogenic surface deposition of unit-II (gravel) suggests uplift

  10. Organic Matter Contents and Paleoproductivity Variation Within Late Pleistocene Japan Sea/East Sea Sediments: Results from IODP Expedition 346

    Science.gov (United States)

    Black, H. D.; Anderson, W. T., Jr.

    2017-12-01

    Inorganic and organic matter concentrations as well as the stable isotopes of nitrogen and organic carbon are presented for continuous sedimentary sequences collected during Integrated Ocean Drilling Program (IODP) Expedition 346 in the Japan Sea/East Sea in 2013. During major glacioeustatic sea level changes, the paleoceanographic conditions within the Japan Sea/East Sea widely vary due to the shallow, narrow straights connecting the sea to surrounding waters limiting an influx of oceanic currents. During glacial sea level low-stands the sea can be nearly isolated, creating a highly-stratified water column and hypoxic to anoxic bottom water conditions. Meanwhile during sea level high-stands, the Tsushima Warm Current (TWC) flows into the sea bringing warmer, nutrient-rich inputs, leading to vertical mixing and oxic conditions. This study aims to better understand the role of orbital cycling within the organic matter and stable isotope contents of these Late Pleistocene sediments. A total of 192 samples were analyzed each for %CaCO3, %TOC, δ13C, %N, and δ15N from two Expedition 346 sampling sites (U1426 and U1427) during the last 430,000 years and statistical analyses were completed using wavelet and time series analyses. Carbonate concentration ranges from 0-44.3%, total organic carbon 0.2 to 6.4%, δ13C -25.8 to -19.6‰, %N 0.04 to 0.4%, and δ15N 3.8 to 13.1‰. These results are well correlated with b* color values of the sediment and generally show increased productivity during interglacial periods, likely through increased vertical mixing and deepwater ventilation, when compared to glacial periods within the Japan Sea/East Sea when the sea may be partially isolated.

  11. Late Pleistocene and Holocene meltwater events in the western Arctic Ocean

    Science.gov (United States)

    Poore, R.Z.; Osterman, L.; Curry, W.B.; Phillips, R.L.

    1999-01-01

    Accelerator mass spectrometer 14C dated stable isotope data from Neogloboquadrina pachyerma in cores raised from the Mendeleyev Ridge and slope provide evidence for significant influx of meltwater to the western Arctic Ocean during the early part of marine oxygen isotope stage 1 (OIS 1) and during several intervals within OIS 3. The strongest OIS 3 meltwater event occurred before ca. 45 ka (conventional radiocarbon age) and was probably related to the deglaciation at the beginning of OIS 3. Major meltwater input to the western Arctic Ocean during the last deglaciation coincides closely with the maximum rate of global sea-level rise as determined from the Barbados sea-level record, demonstrating a strong link between the global record and changes in the central Arctic Ocean. OIS 2, which includes the last glacial maximum, is very condensed or absent in the cores. Abundance and ??13C values for N. pachyderma in the middle part of OIS 3 are similar to modern values, indicating high productivity and seasonal ice-free areas along the Arctic margin at that time. These records indicate that the Arctic Ocean was a source of heat and moisture to the northern polar atmosphere during parts of OIS 3.

  12. A Late Pleistocene clockwise rotation phase of Zakynthos (Greece) and implications for the evolution of the western Aegean arc

    NARCIS (Netherlands)

    Duermeijer, C.E.; Krijgsman, W.; Langereis, C.G.; Meulenkamp, J.E.; Triantaphyllou, M.V.; Zachariasse, W.J.

    1999-01-01

    Palaeomagnetic measurements have been carried out on Eocene to Pleistocene sediments on the Ionian island of Zakynthos, NW Greece. Magnetostratigraphic constraints, biostratigraphic analyses of planktonic foraminifera and calcareous nannofossils provide a reliable time frame for these deposits.

  13. Pleistocene mitochondrial genomes suggest a single major dispersal of non-Africans and a Late Glacial population turnover in Europe

    Czech Academy of Sciences Publication Activity Database

    Posth, C.; Renaud, G.; Mittnik, A.; Drucker, D. G.; Rougier, H.; Cupillard, Ch.; Valentin, F.; Thevenet, C.; Furtwängler, A.; Wissing, Ch.; Francken, M.; Malina, M.; Bolus, M.; Lari, M.; Gigli, E.; Capecchi, G.; Crevecoeur, I.; Beauval, C.; Flas, D.; Germonpré, M.; Plicht van der, J.; Cottiaux, R.; Gély, B.; Ronchitelli, A.; Wehrberger, K.; Grigorescu, D.; Svoboda, Jiří; Semal, P.; Caramelli, D.; Bocherens, H.; Harvati, K.; Conard, N. J.; Haak, W.; Powell, A.; Krause, J.

    2016-01-01

    Roč. 26, March 21 (2016), s. 827-833 ISSN 0960-9822 Institutional support: RVO:68081758 Keywords : mitochondrial genome * Pleistocene * Europe Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 8.851, year: 2016

  14. Early- and Late-Onset Inherited Erythromelalgia

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-08-01

    Full Text Available A genotype-phenotype relationship at the clinical, cellular and molecular levels is shown in a case of erythromelalgia of relatively late onset, in a study at Yale University School of Medicine, and centers in China.

  15. Late-Pleistocene evolution of the East Mediterranean shallow continental shelf of north-central Israel

    Science.gov (United States)

    Shtienberg, Gilad; Dix, Justin; Waldmann, Nicolas; Makovsky, Yizhaq; Bookman, Revital; Roskin, Joel; Bialik, Or; Golan, Arik; Sivan, Dorit

    2016-04-01

    . This approach allowed us to investigate the relationship between the lithological units and sea-level change and thus enable the reconstruction of the coastal evolution over the last ˜130 ka. This reconstruction suggests that the stratigraphy is dominated by a sea level lowstand during which aeolian, fluvial and paleosol sediments were deposited in a terrestrial environment. The coastal-terrestrial landscape was flooded by the early to middle Holocene transgression. The results of this study provide a valuable framework for future national strategic shallow-water infrastructure construction and also for the possible locations of past human settlements in relation to coastal evolution through time.

  16. The ESR dating of fossil enamel samples from palaeo-anthropological and Palaeolithic sites of Early Pleistocene

    International Nuclear Information System (INIS)

    Chen Qi; Chen Tiemei; Li Jiuqiang

    1999-01-01

    The following problems regarding the ESR dating of fossil enamel samples from palaeo-anthropological and Palaeolithic sites of Early Pleistocene are discussed: 1) the applicability of exponential fitting in the additive method for reliable AD determination; 2) the thermo-stability of the g = 2.0018 line of hydroxyapatite and its influence on apparent ESR ages; 3) the right selection of U-uptake models; and 4) the effect of high U-content in enamel on the ESR ages. It is concluded that the ESR-EU ages of Early Pleistocene enamel samples can only be regarded as the lower limit of the true ages if no appropriate corrections for the factors discussed above are made

  17. Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the late(?) Pleistocene

    Science.gov (United States)

    Winograd, Isaac Judah; Doty, Gene C.

    1980-01-01

    Knowledge of the magnitude of water-table rise during Pleistocene pluvial climates, and of the resultant shortening of groundwater flow path and reduction in unsaturated zone thickness, is mandatory for a technical evaluation of the Nevada Test Site (NTS) or other arid zone sites as repositories for high-level or transuranic radioactive wastes. The distribution of calcitic veins filling fractures in alluvium, and of tufa deposits between the Ash Meadows spring discharge area and the Nevada Test Site indicates that discharge from the regional Paleozoic carbonate aquifer during the Late( ) Pleistocene pluvial periods may have occurred at an altitude about 50 meters higher than at present and 14 kilometers northeast of Ash Meadows. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of groundwater base level, suggest possible rises in potentiometric level in the carbonate aquifer of about -90 meters beneath central Frenchman Flat. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters and might even be 10 meters lower than modern levels. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late( ) Pleistocene preclude utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met as this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and long groundwater flow paths characterized the region during the Wisconsin Stage and probably throughout the Pleistocene Epoch and are likely to so characterize it during future glacial periods. (USGS)

  18. Recurrence of water bodies in the hyperarid core of the Atacama Desert - New insights into the Late Pleistocene paleoclimate history of Northern Chile

    Science.gov (United States)

    Diederich, J. L.; Wennrich, V.; Fernández Galego, E.; Ritter, B.; Brill, D.; Niemann, K.; Rolf, C.; Melles, M.

    2017-12-01

    The Atacama Desert of northern Chile is regarded as the driest desert on Earth. Although still controversially discussed, overall arid to hyperarid conditions in the Atacama are thought to have persisted at least since the early Miocene, but were frequently punctuated by pluvial phases. The knowledge of past changes in humidity is strongly hampered by the fact that sediment records from the central Atacama Desert, which enable longer-scale precipitation reconstructions, are rare and mostly restricted to the Miocene/Pliocene or the late Pleistocene <50 kyrs. In this study, we focus on a sediment record from the hyperarid core of the Atacama Desert, derived from a tectonically blocked clay pan in the Coastal Cordillera (20°04'33.64"S, 69°55'01.75"W). This clay pan `Huara' has been initially investigated by a geophysical survey in spring 2015, followed by drilling of a short core (HU-III) covering the uppermost 4 m of sediment. Initial results of the ground penetrating radar (GPR) and horizontal to vertical (H/V) spectral ratio measurements indicate well-stratified sediment bodies in the basin with a maximum sediment infill of 30 ± 4 m. The chronology of core HU-III was established by a combination of optically stimulated luminescence (OSL) and paleomagnetic dating. The sedimentological and geochemical data of core HU-III as well as it's sediment geophysical properties indicate the primary accumulation of fine-grained sediments over the past ca. 50 kyrs, interpreted to be deposited under arid conditions with only sporadic precipitation. Intercalated coarser horizons indicate several periods of semiarid climate conditions, causing multiple phases of local alluvial deposition from the interior catchment area into the clay pan. The results are in agreement with a cosmogenic nuclide study from an adjacent meander system, indicating that the whole sediment sequence of the Huara clay pan covers the regional climate history of the past 500 - 700 kyrs.

  19. Late Pleistocene-Holocene Activity of the Strike-slip Xianshuihe Fault Zone, Tibetan Plateau, Inferred from Tectonic Landforms

    Science.gov (United States)

    Lin, A.; Yan, B.

    2017-12-01

    Knowledges on the activity of the strike-slip fault zones on the Tibetan Plateau have been promoted greatly by the interpretation of remote sensing images (Molnar and Tapponnier, 1975; Tapponnier and Molnar, 1977). The active strike-slip Xianshuihe-Xiaojiang Fault System (XXFS), with the geometry of an arc projecting northeastwards, plays an important role in the crustal deformation of the Tibetan Plateau caused by the continental collision between the Indian and Eurasian plates. The Xianshuihe Fault Zone (XFZ) is located in the central segment of the XXFS and extends for 370 km, with a maximum sinistral offset of 60 km since 13‒5 Ma. In this study, we investigated the tectonic landforms and slip rate along the central segment of the left-lateral strike-slip XFZ. Field investigations and analysis of ttectonic landforms show that horizontal offset has been accumulated on the topographical markers of different scales that developed since the Last Glacial Maximum (LGM). The central segment of the XFZ is composed of three major faults: Yalahe, Selaha, and Zheduotang faults showing a right-stepping echelon pattern, that is characterized by systematical offset of drainages, alluvial fans and terrace risers with typical scissoring structures, indicating a structural feature of left-lateral strike-slip fault. Based on the offset glacial morphology and radiocarbon dating ages, we estimate the Late Pleistocene-Holocene slip rate to be 10 mm/yr for the central segment of the XFZ, which is consistent with that estimated from the GPS observations and geological evidence as reported previously. Across the central segment of the XFZ, the major Selaha and Zheduotang faults participate a slip rate of 5.8 mm/yr and 3.4 mm/yr, respectively. Detailed investigations of tectonic landforms are essential for the understanding the activity of active faults. Our findings suggest that the left-lateral slipping of the XFZ partitions the deformation of eastward extrusion and northeastward

  20. Discussion on the Regional Paleotemperature Evolution since the Late Pleistocene in the Loess Plateau with GDGT as an Index

    Science.gov (United States)

    Yingchun, S.

    2017-12-01

    It is an effective way to understand the modern climate and predict the future climate trend by using the geological substitute indicators to reconstruct the past climate. In recent years, scientists have begun to apply Glycerol dialkyl glycerol tetraethers (GDGTs) to reconstruct paleoclimate and many proxies about ancient air temperature based on GDGTs have been proposed, even the empirical formulas used for China have also been established. In this paper, five loess-paleosol sequences spanning the Late Pleistocene from the Loess Plateau have been used to examine the effectiveness of the formulas as well as to discuss the regional evolution of the ancient temperature of the plateau. The results are as follows: (1) The relative content of iGDGT is higher than that of bGDGT in all Loess sections, and that of each compound follows relatively fixed regularity. Seen from the geographical distribution, the relative content of GDGT in southernmost sections is the highest, which in the northernmost is the smallest. (2) In the last interglacial period, from the northern part to the southern part of the Loess Plateau, the mean annual air temperature (MAAT) of northern Jingbian was 14°, central Luochuan was up to 15°, and southern Weinan was nearly 18°. And at the end of the last glacial period the temperature, where LC and WN located, dropped to 13.5°. Along the east-west direction of the Plateau, in the last interglacial period, the MAAT of western Qin'an secion was 13°, and that of central Baoji and eastern Weinan was about 18°. To the end of the last glacial period, the MAAT decreased to the lowest, Weinan 13.5°, Baoji 14.5°, while Qin'an 10.8°. (3)In contrast to the magnetic susceptibility index, the curves of GDGT MAAT have great similarity with the magnetic susceptibility curve, but it is obvious that there are phase differences between them. That may be indicating that the temperature rise was before the onset of the East-Asian summer monsoon in the Plateau

  1. Early and late synovectomy of the knee in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Jensen, C M; Poulsen, S; Ostergren, M

    1991-01-01

    was reduced and range of motion was unchanged. Total knee alloplasty (TKA) was performed in one knee among the patients who underwent early synovectomy, while reoperation with TKA had been performed in 12 out of 28 knees after late synovectomy. It is concluded that early synovectomy is indicated when medical...... treatment has failed. Late synovectomy must be regarded as a palliative procedure in order to postpone TKA....

  2. Early- versus Late-Onset Dysthymia: A Meaningful Clinical Distinction?

    OpenAIRE

    Sansone, Randy A.; Sansone, Lori A.

    2009-01-01

    In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared ...

  3. The small mammals (Eulipotyphla, Chiroptera, Rodentia and Lagomorpha from the Late Pleistocene site of the cave of El Castillo (Cantabria, Spain

    Directory of Open Access Journals (Sweden)

    C. Sesé

    2018-01-01

    Full Text Available The micromammals remains from the Late Pleistocene site of the cave of El Castillo studied here in detail, came from the Aurignacian levels 18b and 18c (dated in 40.000-45.000 BP, level 19, and the Musterian levels 20b, 20c, 20d, 20e (dated in 41.000-49.000 BP, 21a and 21b. The micromammal association is the following: Erinaceus europaeus, Crocidura russula, Sorex coronatus, Sorex minutus, Neomys fodiens, Talpa europaea, Galemys pyrenaicus, cf. Miniopterus schreibersii, Chiroptera indet., Pliomys lenki, Microtus arvalis – Microtus agrestis, Microtus lusitanicus, Microtus oeconomus, Chionomys nivalis, Arvicola terrestris, Apodemus sylvaticus – Apodemus flavicollis and Lepus sp. Most of these species are in the present fauna of Cantabria, except Pliomys lenki that got extinct in the last third of the Upper Pleistocene, and Microtus oeconomus that disappeared from the Iberian Peninsula during the Holocene, in historical times, and is nowadays present in northern Euroasiatic regions. There is a great continuity of most of the taxa in all the levels. The faunal association seems to indicate a mainly open environment, in general with wet meadows (and few dry meadows, with good vegetation cover in the soil, with perhaps also some tree-covered areas, and some watercourses. The thermophiles indicators are very scarce, which could indicate that the climate could be a lesser temperate than other Upper Pleistocene periods and the present-day climate in the area.

  4. Oldest human occupation of Wallacea at Laili Cave, Timor-Leste, shows broad-spectrum foraging responses to late Pleistocene environments

    Science.gov (United States)

    Hawkins, Stuart; O'Connor, Sue; Maloney, Tim Ryan; Litster, Mirani; Kealy, Shimona; Fenner, Jack N.; Aplin, Ken; Boulanger, Clara; Brockwell, Sally; Willan, Richard; Piotto, Elena; Louys, Julien

    2017-09-01

    The Wallacea Archipelago provides an extraordinary laboratory for the study of human colonisation and adaptation, yet few detailed archaeological studies have been conducted in the region that span the earliest phase of human settlement. Laili Cave, in northern Timor-Leste, preserves the oldest human occupation in this insular region with a cultural sequence spanning 11,200 to 44,600 cal BP. Small-bodied vertebrates and invertebrates were recovered to the lowest excavated levels, associated with highly concentrated stone artefacts. We report on human behavioural adaptations within the context of Pleistocene environments and changing landscapes using zooarchaeological, stone artefact, bathymetric, and experimental isotopic analyses. Results indicate that Pleistocene humans used the abundant local chert liberally and engaged in mobile broad-spectrum exploitation of invertebrates and fishes from marine, estuarine, and freshwater environments within close proximity of Laili Cave. The faunal assemblage indicates heterogeneous but relatively stable environments during the late Pleistocene. Variability in subsistence strategies over time appears to be a response to changing landscapes and concomitant local resources. This record contrasts with marine specialisations evident from other sites in Timor-Leste and within the broader Wallacean region.

  5. ANÁLISIS FUNCIONALES EN ARTEFACTOS LÍTICOS DE GRUPOS CAZADORES-RECOLECTORES EN REGIONES TROPICALES DURANTE LA TRANSICIÓN PLEISTOCENO FINAL-HOLOCENO TEMPRANO: EL ABRIGO SANTA MARTA, CHIAPAS, MÉXICO (Functional Analysis of Lithic Artifacts of Hunter-Gatherer Groups in Tropical Regions During the Late Pleistocene-Early Holocene Transition: Santa Marta's Shelter, Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Patricia Pérez Martínez

    2018-03-01

    Full Text Available Los análisis funcionales vieron la luz en la década de los sesenta con la publicación de la Tecnología Prehistórica de Semenov (1964, desde entonces se ha realizado un gran número de investigaciones para dilucidar actividades de subsistencia a partir de la funcionalidad de los artefactos. Desafortunadamente, en México pocos han sido los trabajos enfocados a este tipo de análisis (Elizalde y Mandujano 2000; Lewenstein 1990; Mirambell 1964. En el presente estudio se analizaron microscópicamente 36 artefactos líticos con el objetivo de caracterizar los micropulidos e inferir la funcionalidad de estos conjuntos asociados a grupos cazadores-recolectores procedentes de contextos de la transición Pleistoceno-Holoceno (13130-12671 cal. AP. ENGLISH: Use-wear studies began in the 1960s with Semenov’s publication entitled Prehistoric Technology (1964. Since then, a great number of investigations have been carried out to elucidate subsistence activities based on the functionality of the artifacts. Unfortunately, in Mexico few studies have focused on this type of analysis (Elizalde & Mandujano 2000; Lewenstein 1990; Mirambell 1964. In the present study, 36 lithic artifacts associated with hunter-gatherer groups from Pleistocene-Holocene transition contexts (13130–12671 cal. AP were analyzed microscopically with the aim of characterizing micropolishes and inferring functionality.

  6. Abnormal carbonate diagenesis in Holocene-late Pleistocene sapropel-associated sediments from the Eastern Mediterranean; Evidence from Emiliania huxleyi coccolith morphology

    DEFF Research Database (Denmark)

    Crudeli, D.; Young, J.R.; Erba, E.

    2004-01-01

    In studying the Holocene-late Pleistocene record of the Eastern Mediterranean, considerable Emiliania huxleyi size/shape variation not clearly assignable to primary or secondary calcification was observed. Accordingly, different morphotypes were distinguished by light microscope (LM). A subsequent......, but also that they show effects of carbonate precipitation and dissolution much more clearly than other coccoliths. The relative abundances of the different LM-morphotypes were used to define an E. huxleyi overgrowth index (EXO) that qualitatively estimates carbonate precipitation/dissolution on coccoliths...

  7. Palaeovegetation dynamics of an ecotone forest-savanna in southern Brazilian Amazon during the late Pleistocene and Holocene based on carbon isotopes of soil organic matter

    International Nuclear Information System (INIS)

    Pessenda, L.C.R.; Gouveia, S.E.M.; Freitas, H.A. de; Bendassoli, J.A.; Gomes, B.M.; Aravena, R.; Ribeiro, A.S.; Boulet, R.

    2002-01-01

    This study was carried out in the Brazilian southern Amazon region (Rondonia state and Humaita, southern Amazon state). Carbon isotope data on soil organic matter have been collected along an ecosystem transect of about 750 km that includes a savanna, a wooded savanna (cerrado), a tropical semideciduous forest (cerradao), a forest transition type and a tropical forest. The main objective is to evaluate the expansion-regression dynamics of these vegetation units in relation to climate changes during the Late Pleistocene (Late Glacial) and Holocene. Large ranges in δ 13 values were observed in soil organic matter collected from profiles in the savanna (-27 to -14 per mille and forest regions (-26 to -19 per mille) reflecting changing distribution of 13 C-depleted C 3 forest and 13 C enriched C 4 savanna vegetation in response to climate change. 14 C data of humin fraction and buried charcoal indicate that the organic matter in these soils is at least 17,000 years BP at 300-cm depth. In this period, the entire ecosystem transect are characterized by δ 13 C soil depth profiles, generated typically by C 3 plants (forest), inferring a humid climate in the southern Amazon region after the end of last glaciation. 13 C data also indicate that C 4 plants (grasses) have influenced significantly the vegetation at the transitional forest and the cerrado sites of southern Rondonia state and two distinct points in the forest ecosystem in the southern Amazon state. These typical C 4 type isotopic signatures probably reflect a drier climate during about 9000-8000 yr BP to 3000 yr BP and the savanna and wooded savanna expansion in distinct points of the transect. The 13 C records representing the 3000 yr show an expansion of the forest, due to a climatic improvement, in areas previously occupied by savanna vegetation. This study adds to the mounting evidence that extensive forested areas existed in the Amazon during the last glacial and that savanna vegetation expanded in response

  8. Cognitive advantages and disadvantages in early and late bilinguals.

    Science.gov (United States)

    Pelham, Sabra D; Abrams, Lise

    2014-03-01

    Previous research has documented advantages and disadvantages of early bilinguals, defined as learning a 2nd language by school age and using both languages since that time. Relative to monolinguals, early bilinguals manifest deficits in lexical access but benefits in executive function. We investigated whether becoming bilingual after childhood (late bilinguals) can produce the cognitive advantages and disadvantages typical of early bilinguals. Participants were 30 monolingual English speakers, 30 late English-Spanish bilinguals, and 30 early Spanish-English bilinguals who completed a picture naming task (lexical access) and an attentional network task (executive function). Late and early bilinguals manifested equivalent cognitive effects in both tasks, demonstrating lexical access deficits and executive function benefits. These findings provide support for the hypothesis that cognitive effects associated with bilingualism arise as the result of proficient, habitual use of 2 languages and not of developmental changes associated with becoming bilingual during childhood.

  9. New Constraints on Late Pleistocene - Holocene Slip Rates and Seismic Behavior Along the Panamint Valley Fault Zone, Eastern California

    Science.gov (United States)

    Hoffman, W.; Kirby, E.; McDonald, E.; Walker, J.; Gosse, J.

    2008-12-01

    buried by the debris-flow lobe, exhibit progressively larger displacement (up to 10-12 m). Well-preserved bar and swale morphology, incipient varnishing of surface boulders, and weak soil development all suggest that this surface is Late Holocene in age. We are working to confirm this inference, but if correct, it suggests that this fault system may have experienced ~3-4 events in the relatively recent past. Finally, preliminary surface ages from even older surfaces along this portion of the fault zone place limits on the slip rate over Late Pleistocene time. Cosmogenic 10Be surface clast dating of an alluvial surface with well-developed pavement and moderate soil development near Happy Canyon suggests a surface age of 30-35 kyr. We are working to refine this estimate with new dating and soil characterization, but our preliminary reconstructions of displacement of this surface across the two primary fault strands are consistent with slip rates that exceed ~3 mm/yr. Overall, these results are consistent with the inference that the Panamint Valley fault zone is the primary structure that accomplishes transfer of right-lateral shear across the Garlock Fault.

  10. Late Pleistocene and Holocene-Age Columbia River Sediments and Bedforms: Hanford Reach Area, Washington - Part 2

    Energy Technology Data Exchange (ETDEWEB)

    K.R. Fecht, T.E. Marceau

    2006-03-28

    This report presents the results of a geologic study conducted on the lower slopes of the Columbia River Valley in south-central Washington. The study was designed to investigate glaciofluvial and fluvial sediments and bedforms that are present in the river valley and formed subsequent to Pleistocene large-scale cataclysmic flooding of the region.

  11. Genetic consequences of population expansions and contractions in the common hippopotamus (Hippopotamus amphibius) since the Late Pleistocene

    DEFF Research Database (Denmark)

    Stoffel, Céline; Dufresnes, Christophe; Okello, John B A

    2015-01-01

    Over the past two decades, an increasing amount of phylogeographic work has substantially improved our understanding of African biogeography, in particular the role played by Pleistocene pluvial-drought cycles on terrestrial vertebrates. However, still little is known on the evolutionary history...

  12. Subglacial bed conditions during Late Pleistocene glaciations and their impact on ice dynamics in the southern North Sea

    NARCIS (Netherlands)

    Passchier, S.; Laban, C.; Mesdag, C.S.; Rijsdijk, K.F.

    2010-01-01

    Changes in subglacial bed conditions through multiple glaciations and their effect on ice dynamics are addressed through an analysis of glacigenic sequences in the Upper Pleistocene stratigraphy of the southern North Sea basin. During Elsterian (MIS 12) ice growth, till deposition was subdued when

  13. So Close, yet So Far Away: Early vs. Late Dropouts

    Science.gov (United States)

    Ma, Yanli; Cragg, Kristina M.

    2013-01-01

    While some students drop out early in their academic career, others drop out close to completion. What similarities and differences exist between these early and late dropouts? Using a sample 3,520 first-time, full-time (FTFT) students seeking a bachelor's degree at a state university, this study employs multinomial logistic regression to model…

  14. Late Miocene-Pleistocene evolution of a Rio Grande rift subbasin, Sunshine Valley-Costilla Plain, San Luis Basin, New Mexico and Colorado

    Science.gov (United States)

    Ruleman, C.A.; Thompson, R.A.; Shroba, R.R.; Anderson, M.; Drenth, B.J.; Rotzien, J.; Lyon, J.

    2013-01-01

    The Sunshine Valley-Costilla Plain, a structural subbasin of the greater San Luis Basin of the northern Rio Grande rift, is bounded to the north and south by the San Luis Hills and the Red River fault zone, respectively. Surficial mapping, neotectonic investigations, geochronology, and geophysics demonstrate that the structural, volcanic, and geomorphic evolution of the basin involves the intermingling of climatic cycles and spatially and temporally varying tectonic activity of the Rio Grande rift system. Tectonic activity has transferred between range-bounding and intrabasin faults creating relict landforms of higher tectonic-activity rates along the mountain-piedmont junction. Pliocene–Pleistocene average long-term slip rates along the southern Sangre de Cristo fault zone range between 0.1 and 0.2 mm/year with late Pleistocene slip rates approximately half (0.06 mm/year) of the longer Quaternary slip rate. During the late Pleistocene, climatic influences have been dominant over tectonic influences on mountain-front geomorphic processes. Geomorphic evidence suggests that this once-closed subbasin was integrated into the Rio Grande prior to the integration of the once-closed northern San Luis Basin, north of the San Luis Hills, Colorado; however, deep canyon incision, north of the Red River and south of the San Luis Hills, initiated relatively coeval to the integration of the northern San Luis Basin.Long-term projections of slip rates applied to a 1.6 km basin depth defined from geophysical modeling suggests that rifting initiated within this subbasin between 20 and 10 Ma. Geologic mapping and geophysical interpretations reveal a complex network of northwest-, northeast-, and north-south–trending faults. Northwest- and northeast-trending faults show dual polarity and are crosscut by north-south– trending faults. This structural model possibly provides an analog for how some intracontinental rift structures evolve through time.

  15. Early and Late Rate of Force Development

    DEFF Research Database (Denmark)

    Andersen, Lars L; Andersen, Jesper L; Zebis, Mette K

    2010-01-01

    The objective of this study is to investigate the potentially opposing influence of qualitative and quantitative muscular adaptations in response to high-intensity resistance training on contractile rate of force development (RFD) in the early (<100 ms) and later phases (>200 ms) of rising muscle...

  16. Early Pleistocene archaeological occurrences at the Feiliang site, and the archaeology of human origins in the Nihewan Basin, North China.

    Directory of Open Access Journals (Sweden)

    Shuwen Pei

    Full Text Available The Early Pleistocene archaeological evidence from the fluvio-lacustrine sequence of the Nihewan Basin (North China offers an excellent opportunity to explore early human evolution and behavior in a temperate setting in East Asia, following the earliest 'Out of Africa'. Here we present the first comprehensive study of the Feiliang (FL site, with emphasis on the archaeological sequence, site integrity, and stone artifact assemblages. Magnetostratigraphic dating results show that early humans occupied the site ca. 1.2 Ma. Archaeological deposits were buried rapidly in primary context within shallow lake margin deposits, with only minor post-depositional disturbance from relatively low energy hydraulic forces. The FL lithic assemblage is characterized by a core and flake, Oldowan-like or Mode 1 technology, with a low degree of standardization, expedient knapping techniques, and casually retouched flakes. The bone assemblage suggests that hominin occupation of the FL site was in an open habitat of temperate grassland with areas of steppe and water. The main features of the FL assemblage are discussed in the context of the early Pleistocene archaeology of Nihewan, for which an assessment of current and future research is also presented.

  17. Contemporaneous trace and body fossils from a late Pleistocene Lakebed in Victoria, Australia, allow assessment of bias in the fossil record.

    Science.gov (United States)

    Camens, Aaron Bruce; Carey, Stephen Paul

    2013-01-01

    The co-occurrence of vertebrate trace and body fossils within a single geological formation is rare and the probability of these parallel records being contemporaneous (i.e. on or near the same bedding plane) is extremely low. We report here a late Pleistocene locality from the Victorian Volcanic Plains in south-eastern Australia in which demonstrably contemporaneous, but independently accumulated vertebrate trace and body fossils occur. Bite marks from a variety of taxa are also present on the bones. This site provides a unique opportunity to examine the biases of these divergent fossil records (skeletal, footprints and bite marks) that sampled a single fauna. The skeletal record produced the most complete fauna, with the footprint record indicating a markedly different faunal composition with less diversity and the feeding traces suggesting the presence, amongst others, of a predator not represented by either the skeletal or footprint records. We found that the large extinct marsupial predator Thylacoleo was the only taxon apparently represented by all three records, suggesting that the behavioral characteristics of large carnivores may increase the likelihood of their presence being detected within a fossil fauna. In contrast, Diprotodon (the largest-ever marsupial) was represented only by trace fossils at this site and was absent from the site's skeletal record, despite its being a common and easily detected presence in late Pleistocene skeletal fossil faunas elsewhere in Australia. Small mammals absent from the footprint record for the site were represented by skeletal fossils and bite marks on bones.

  18. High resolution magnetostratigraphy and raio-isotope dating of early Pleistocene lake sediments from southern Armenia

    NARCIS (Netherlands)

    Kirscher, U.; Bruch, A.A.; Gabrielyan, I.; Scharrer, S.; Kuiper, K.F.; Bachtadse, V.

    2014-01-01

    The Pleistocene geology of Armenia is dominated by widespread occurrence of sediments recording recurring rapid and drastic changes of the environmental conditions during at least the last 2 million years. These sediments, predominantly diatomites, contain a huge variety of various fossil remains,

  19. Sedimentation and erosion processes in Middle to Late Pleistocene sequences exposed in the brickyard of Langenlois/Lower Austria

    DEFF Research Database (Denmark)

    Thiel, Christine; Terhorst, Birgit; Jaburová, Iva

    2011-01-01

    The correlation of sedimentary and pedogenetic processes in Lower Austria is difficult due to significant discontinuities and local variability in soil formation. This hampers landscape reconstruction at a regional scale. However, at a local scale distinct landscape formation processes represented...... by a shift from fluvial to aeolian deposition can be observed in the brickyard of Langenlois, Lower Austria. Sedimentological and mineralogical analyses in combination with palaeontological finds suggest that the fluvial deposition took place during the Middle Pleistocene. This attribution is confirmed...... in Austria; it indicates a Middle Pleistocene interglacial period. The low degree of weathering as well as Cryosols found in the loess sequence point to loess accumulation during the Last Glacial; the dating results (35–55 ka) indicate prolonged loess deposition. No signs of pedogenesis could be found...

  20. Land-sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    Science.gov (United States)

    Donders, Timme H.; van Helmond, Niels A. G. M.; Verreussel, Roel; Munsterman, Dirk; ten Veen, Johan; Speijer, Robert P.; Weijers, Johan W. H.; Sangiorgi, Francesca; Peterse, Francien; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.; Lourens, Lucas; Kuhlmann, Gesa; Brinkhuis, Henk

    2018-03-01

    We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (˜ 2.6-1.8 Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG) in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial-interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS) 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST), vegetation, relative sea level, and coastal influence.During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct warm-cold alterations are

  1. Land–sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    Directory of Open Access Journals (Sweden)

    T. H. Donders

    2018-03-01

    Full Text Available We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (∼ 2.6–1.8 Ma multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial–interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST, vegetation, relative sea level, and coastal influence.During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct

  2. Geologic Setting and Preservation of a Late Pleistocene Bald Cypress Forest Discovered on the Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Gonzalez Rodriguez, S. M.; Bentley, S. J.; DeLong, K. L.; Xu, K.; Harley, G. L.; Reese, C. A.; Obelcz, J.

    2016-02-01

    Following landfall of Hurricane Ivan in 2004, a previously buried bald cypress forest (Taxodium distichum) was discovered on the continental shelf seafloor, offshore of Orange Beach, Alabama, USA, in 20 m of water. The forest is preserved as stumps in life position with little evidence of decay and large pieces of trunks, roots, and branches. Analysis shows the forest is older than can be dated with conventional C-14 methods. Comparison of Pleistocene sea level curves with the study area depth suggests that the forest developed and was likely buried during marine isotope stage 3 or 4, or perhaps older stages. Condition of sampled wood suggests that the forest was buried and preserved in anoxic sediments for millennia, prior to recent exhumation. To better understand the puzzling geological conditions that could allow forest preservation during sea level fall and shelf exposure spanning >30,000 years, submersible vibracores (to 6 m length) and geophysical data (swath bathymetry, sidescan, and chirp subbottom) were collected in August 2015. Cores are being analyzed using a Geotek Multi Sensor Core Logger, granulometric and sediment composition analyses, and a wide range of paleoenvironmental observations. This presentation focuses on the geological setting and mode of forest preservation. Preliminary analysis of sediment types and stratigraphy in cores shows that the local stratigraphy is broadly consistent with previous regional shelf-stratigraphic studies, consisting of (top to bottom) a surface layer of Holocene transgressive sands (to 3 m thick) unconformably overlying Pleistocene terrestrial and coastal deposits. However, the Pleistocene lithofacies (fluvial, backswamp, or possibly delta plain muds) differ considerably in both depositional environment and degree of environmental preservation compared to previous studies. Ongoing analysis will focus on elucidating the succession of events that allows preservation of this unique Pleistocene sedimentary archive.

  3. Early versus Late Parenteral Nutrition in Critically Ill Children.

    Science.gov (United States)

    Fivez, Tom; Kerklaan, Dorian; Mesotten, Dieter; Verbruggen, Sascha; Wouters, Pieter J; Vanhorebeek, Ilse; Debaveye, Yves; Vlasselaers, Dirk; Desmet, Lars; Casaer, Michael P; Garcia Guerra, Gonzalo; Hanot, Jan; Joffe, Ari; Tibboel, Dick; Joosten, Koen; Van den Berghe, Greet

    2016-03-24

    Recent trials have questioned the benefit of early parenteral nutrition in adults. The effect of early parenteral nutrition on clinical outcomes in critically ill children is unclear. We conducted a multicenter, randomized, controlled trial involving 1440 critically ill children to investigate whether withholding parenteral nutrition for 1 week (i.e., providing late parenteral nutrition) in the pediatric intensive care unit (ICU) is clinically superior to providing early parenteral nutrition. Fluid loading was similar in the two groups. The two primary end points were new infection acquired during the ICU stay and the adjusted duration of ICU dependency, as assessed by the number of days in the ICU and as time to discharge alive from ICU. For the 723 patients receiving early parenteral nutrition, parenteral nutrition was initiated within 24 hours after ICU admission, whereas for the 717 patients receiving late parenteral nutrition, parenteral nutrition was not provided until the morning of the 8th day in the ICU. In both groups, enteral nutrition was attempted early and intravenous micronutrients were provided. Although mortality was similar in the two groups, the percentage of patients with a new infection was 10.7% in the group receiving late parenteral nutrition, as compared with 18.5% in the group receiving early parenteral nutrition (adjusted odds ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66). The mean (±SE) duration of ICU stay was 6.5±0.4 days in the group receiving late parenteral nutrition, as compared with 9.2±0.8 days in the group receiving early parenteral nutrition; there was also a higher likelihood of an earlier live discharge from the ICU at any time in the late-parenteral-nutrition group (adjusted hazard ratio, 1.23; 95% CI, 1.11 to 1.37). Late parenteral nutrition was associated with a shorter duration of mechanical ventilatory support than was early parenteral nutrition (P=0.001), as well as a smaller proportion of patients

  4. Pliocene to early Middle Pleistocene ursine bears in Europe: a taxonomic overview

    Czech Academy of Sciences Publication Activity Database

    Wagner, Jan

    2010-01-01

    Roč. 179, - (2010), s. 197-215 ISSN 1802-6842 R&D Projects: GA ČR GA205/09/0184; GA AV ČR IAA300130701 Institutional research plan: CEZ:AV0Z30130516 Keywords : Ursus * taxonomy * Pliocene * Pleistocene Subject RIV: DB - Geology ; Mineralogy http://www.nm.cz/publikace/publikace-download.php?name=File1&dir=archiv&table=tabPublikaceArchiv&id=2796

  5. A Cost-effectiveness Analysis of Early vs Late Tracheostomy.

    Science.gov (United States)

    Liu, C Carrie; Rudmik, Luke

    2016-10-01

    The timing of tracheostomy in critically ill patients requiring mechanical ventilation is controversial. An important consideration that is currently missing in the literature is an evaluation of the economic impact of an early tracheostomy strategy vs a late tracheostomy strategy. To evaluate the cost-effectiveness of the early tracheostomy strategy vs the late tracheostomy strategy. This economic analysis was performed using a decision tree model with a 90-day time horizon. The economic perspective was that of the US health care third-party payer. The primary outcome was the incremental cost per tracheostomy avoided. Probabilities were obtained from meta-analyses of randomized clinical trials. Costs were obtained from the published literature and the Healthcare Cost and Utilization Project database. A multivariate probabilistic sensitivity analysis was performed to account for uncertainty surrounding mean values used in the reference case. The reference case demonstrated that the cost of the late tracheostomy strategy was $45 943.81 for 0.36 of effectiveness. The cost of the early tracheostomy strategy was $31 979.12 for 0.19 of effectiveness. The incremental cost-effectiveness ratio for the late tracheostomy strategy compared with the early tracheostomy strategy was $82 145.24 per tracheostomy avoided. With a willingness-to-pay threshold of $50 000, the early tracheostomy strategy is cost-effective with 56% certainty. The adaptation of an early vs a late tracheostomy strategy depends on the priorities of the decision-maker. Up to a willingness-to-pay threshold of $80 000 per tracheostomy avoided, the early tracheostomy strategy has a higher probability of being the more cost-effective intervention.

  6. The Cova des Pas de Vallgornera (Llucmajor, Mallorca: a singular deposit bearing an exceptional well preserved Early Pleistocene vertebrate fauna

    Directory of Open Access Journals (Sweden)

    Pere Bover

    2014-05-01

    Full Text Available The Cova des Pas de Vallgornera is the longest cave of Mallorca (Balearic Islands, Western Mediterranean and one of the 30 longest caves in the world. The exploration of one of the galleries allowed the discovery of a fossiliferous deposit of vertebrate remains in a remarkable preservation state. The fossil faunal complex found in this gallery is composed of up to 5 mammalian species (Myotragus aff. kopperi, Hypnomys onicensis, Nesiotites aff. ponsi, Rhinolophus aff. mehelyi and Pipistrellus sp., at least 14 bird species (among them two Mallorcan endemic taxa: Pica mourerae and Athene vallgornerensis, one reptile (Podarcis aff. lilfordi and one amphibian (Discoglossus sp.. This faunal composition is similar to the one recorded in the Pedrera de s’Ònix, a well known deposit from the Early Pleistocene of Mallorca, and shared morphological characteristics between taxa of both deposits suggest that the chronology of the Cova des Pas de Vallgornera should be considered Early Pleistocene as well. Both taxonomical analysis and chronology of this fauna furnished information on some speleological aspects of the cave.

  7. Early Pleistocene human hand phalanx from the Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain).

    Science.gov (United States)

    Lorenzo, Carlos; Pablos, Adrián; Carretero, José Miguel; Huguet, Rosa; Valverdú, Josep; Martinón-Torres, María; Arsuaga, Juan Luis; Carbonell, Eudald; Bermúdez de Castro, José María

    2015-01-01

    In this study, a new Early Pleistocene proximal hand phalanx (ATE9-2) from the Sima del Elefante cave site (TE - Sierra de Atapuerca, Spain), ascribed to Homo sp., is presented and comparatively described in the context of the evolution of the genus Homo. The ATE9-2 specimen is especially important because of the paucity of hand bones in the human fossil record during the Early Pleistocene. The morphological and metrical analyses of the phalanx ATE9-2 indicate that there are no essential differences between it and comparator fossil specimens for the genus Homo after 1.3 Ma (millions of years ago). Similar to Sima de los Huesos and Neandertal specimens, ATE9-2 is a robust proximal hand phalanx, probably reflecting greater overall body robusticity in these populations or a higher gracility in modern humans. The age of level TE9 from Sima del Elefante and morphological and metrical studies of ATE9-2 suggest that the morphology of the proximal hand phalanges and, thus, the morphology of the hand could have remained stable over the last 1.2-1.3 Ma. Taking into account the evidence recently provided by a metacarpal from Kaitio (Kenya) from around 1.42 Ma, we argue that modern hand morphology is present in the genus Homo subsequent to Homo habilis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. ON THE PALEOFAUNA INVERTEBRATES (MOLLUSCA, ARTROPODA; INSECTA OF DIATOMITE DEPOSITS OF SHAMB–1 LOCALITY (SISIAN SUITE, EARLY PLEISTOCENE, ARMENIA

    Directory of Open Access Journals (Sweden)

    М. A. Маrjanyan

    2016-01-01

    Full Text Available Aim. The study of fossil insects from diatomaceous sediments of Shamb-1 locality of Sisian Suite (Early Pleistocene. The collection of fossils plants and animals of Institute of Botany of NAS RA and authors' findings served as material for study.Methods. The material is processed and prepared for study by conventional methods in paleontology for prints and fossils of insects from diatomaceous sediments. There are 654 samples studied: 2 samples were with mollusks’ imprints and 652 samples with imprints of insects, from which preserved marks on 291samples allowed to identify them up to order, family, genus and species.Results. The studied material refers to the Mollusca and Arthropoda (Insecta types. Insects are represented by species of orders Orthoptera (2 fam., Homoptera (1 fam., Heteroptera (2 fam., Coleoptera (15 fam., Hymenoptera (2 fam., Diptera (1 fam.. Coleopteras dominate among them and are presented with following species of the family – Carabidae, Dytiscidae, Hydrophilidae, Histeridae, Staphylinidae, Silphidae, Elateridae, Buprestidae, Lampyridae, Scarabaeidae, Chrysomelidae, Tenebrionidae, Coccinellidae, Cerambycidae, Curculionidae.Main conclusions. An analysis of the taxonomic composition of paleofauna was done, which corresponds to the recent fauna and with considering modern ecological characteristics of systematical groups and species. In the investigated location of Shamb-1 a version is suggested about the palaeolandscapes and palaeoclimate in the Early Pleistocene.

  9. Late Pleistocene sea-level changes recorded in tidal and fluvial deposits from Itaubal Formation, onshore portion of the Foz do Amazonas Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Isaac Salém Alves Azevedo Bezerra

    Full Text Available ABSTRACTThe Pleistocene deposits exposed in the Amapá Coastal Plain (onshore portion of the Foz do Amazonas Basin, northeastern South America were previously interpreted as Miocene in age. In this work, they were named as "Itaubal Formation" and were included in the quaternary coastal history of Amazonia. The study, through facies and stratigraphic analyses in combination with optically stimulated luminescence (single and multiple aliquot regeneration, allowed interpreting this unit as Late Pleistocene tidal and fluvial deposits. The Itaubal Formation, which unconformably overlies strongly weathered basement rocks of the Guianas Shield, was subdivided into two progradational units, separated by an unconformity related to sea-level fall, here named as Lower and Upper Units. The Lower Unit yielded ages between 120,600 (± 12,000 and 70,850 (± 6,700 years BP and consists of subtidal flat, tide-influenced meandering stream and floodplain deposits, during highstand conditions. The Upper Unit spans between 69,150 (± 7,200 and 58,150 (± 6,800 years BP and is characterized by braided fluvial deposits incised in the Lower Unit, related to base-level fall; lowstand conditions remained until 23,500 (± 3,000 years BP. The studied region was likely exposed during the Last Glacial Maximum and then during Holocene, covered by tidal deposits influenced by the Amazon River.

  10. NEW FOSSIL VERTEBRATE REMAINS FROM SAN GIOVANNI DI SINIS (LATE PLEISTOCENE, SARDINIA: THE LAST MAUREMYS (REPTILIA, TESTUDINES IN THE CENTRAL MEDITERRANEAN

    Directory of Open Access Journals (Sweden)

    FRANCESCO CHESI

    2007-07-01

    Full Text Available New fossil vertebrates from the most representative Upper Pleistocene section (Tyrrhenian, MIS 5e of the outcrop of San Giovanni di Sinis (Oristano, Sardinia are here reported and described. The fossils, although scarce and fragmentary, document the occurrence of a terrapin (Mauremys sp. and the endemic Sardinian deer (Praemegaceros cazioti. Significant is the occurrence of the terrapin because it is the youngest representative of the genus in the central Mediterranean area where it is extinct at present. The Late Pleistocene extinction of Mauremys in Italy follows the same pattern of other Mediterranean reptiles, in being in some cases delayed on the islands. A comparison of the modern range of Mauremys and that of the pond turtle, Emys, as well as of their past ranges as evidenced by the fossil record, might suggest that some sort of thermophily (at least during pre-hatching stages characterized the former taxon and is responsible for its past and present distribution. SHORT NOTE

  11. Mobile ICT use in early adopter vs. late majority countries

    DEFF Research Database (Denmark)

    Gimpel, Gregory; Sudzina, Frantisek; Petrovcikova, Katarina

    2016-01-01

    The rapid global diffusion of smartphones has not been uniform. This study uses Triandis’ theory of interpersonal behaviour to investigate what drives smartphone use in early adopter (USA) versus late majority (Slovakia) countries. By surveying both current and potential owners, we also revisit K...

  12. Geomagnetic modulation of the late Pleistocene cosmic-ray flux as determined by 10Be from Blake Outer Ridge marine sediments

    International Nuclear Information System (INIS)

    McHargue, L.R.; Donahue, D.; Damon, P.E.; Sonett, C.P.; Biddulph, D.; Burr, G.

    2000-01-01

    The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20-60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10 Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10 Be in the authigenic fraction of the sediments from Blake Ridge closely correlates with the inverse of the variance in the paleointensity of the geomagnetic field. The 10 Be signal lags, up to 1000 years of sedimentation, the measured paleointensity of the sediments. In contrast, the data from several other elements, some climatically sensitive, and from beryllium show relationship neither to 10 Be nor to the paleomagnetic data. The relationship between 10 Be concentration and the dipole field intensity (M/M o ) as measured in the sediments is consistent with theoretical models

  13. The late Pleistocene horned crocodile Voay robustus (Grandidier & Vaillant, 1872 from Madagascar in the Museum für Naturkunde Berlin

    Directory of Open Access Journals (Sweden)

    C. Bickelmann

    2009-02-01

    Full Text Available Crocodylian material from late Pleistocene localities around Antsirabe, Madagascar, stored in the collection of the Museum für Naturkunde, Berlin, was surveyed. Several skeletal elements, including skull bones, vertebrae, ribs, osteoderms, and limb bones from at least three large individuals could be unambiguously assigned to the genus Voay Brochu, 2007. Furthermore, the simultaneous occurrence of Voay robustus Grandidier & Vaillant, 1872 and Crocodylus niloticus Laurenti, 1768 in Madagascar is discussed. Voay robustus and Crocodylus niloticus are systematically separate but similar in stature and size, which would make them direct rivals for ecological resources. Our hypothesis on the extinction of the species Voay, which was endemic to Madagascar, suggests that C. niloticus invaded Madagascar only after V. robustus became extinct. doi:10.1002/mmng.200800007

  14. The Late Pleistocene-Holocene community development in Central and SE-Europe in direct fossil record: scope of the approach, common patterns and inter-regional differences.

    Science.gov (United States)

    Horacek, Ivan; Lozek, Vojen

    2010-05-01

    The information provided by modern instrumental approaches (molecular phylogeography, ancient DNA analyses, large scale radiocarbon datings etc.) refined the knowledge on Late Quaternary faunal development and range history of particular taxa in essential way. Nevertheless, the direct fossil record remains still an essential substrate in study of that topics, and to reveal all the information, that it may provide, and integrate it with the outputs of the other approaches presents one of the essential aim of the present meeting. Unfortunately, the immediate use of fossil record for the paleoecologic and paleobiogeographic inferences is often limited by its fragmentarity (both in temporal and spatial respects), taphonomic influences and/or locally specific post-sedimentary effects which all may bias it in a considerable degree. Hence, each particular record is to be carefully reexamined in respect to all factor which may bias it - unfortunately, often it is not too easy to respond that task, particularly when the record is retrived from secondary sources. It should also be remembered that the records representing narrow time slices without a robust lithostratigraphic context do not provide any information on the historical and contextual setting of the respective faunal situation. Such information that is essential for reconstructions of paleobiogeography of community development and similar locally-sensitive phenomena can only be retrived from the continuous sedimentary series which establish the sequence of particular faunal events by direct superposition. A sufficiently dense network of such series provides than a possibility of direct inter-regional comparisons and a high resolution information on the paleobiogeography of the Late Pleistocene-Holocene rearrangements of mammalian communities, local variation in history of particular species and its community context. We illustrate productivity of such approach on with aid of the fossil record obtained from

  15. Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of Southern California: implications for understanding the paleoenvironment of the Late Pleistocene.

    Directory of Open Access Journals (Sweden)

    Anna R Holden

    Full Text Available The Rancho La Brea Tar Pits is the world's richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironemental indicators due to their narrow climate restrictions and life cycles. Our goal was to examine fossil material that included insect-plant associations, and thus an even higher potential for significant paleoenviromental data. Micro-CT scans of two exceptionally preserved leafcutter bee nest cells from the Rancho La Brea Tar Pits in Los Angeles, California reveal intact pupae dated between ∼23,000-40,000 radiocarbon years BP. Here identified as best matched to Megachile (Litomegachile gentilis Cresson (Hymenoptera: Megachilidae based on environmental niche models as well as morphometrics, the nest cells (LACMRLP 388E document rare preservation and life-stage. The result of complex plant-insect interactions, they offer new insights into the environment of the Late Pleistocene in southern California. The remarkable preservation of the nest cells suggests they were assembled and nested in the ground where they were excavated. The four different types of dicotyledonous leaves used to construct the cells were likely collected in close proximity to the nest and infer a wooded or riparian habitat with sufficient pollen sources for larval provisions. LACMRLP 388E is the first record of fossil Megachile Latreille cells with pupae. Consequently, it provides a pre-modern age location for a Nearctic group, whose phylogenetic relationships and biogeographic history remain poorly understood. Megachile gentilis appears to respond to climate change as it has expanded its distribution across elevation gradients over time as estimated by habitat suitability comparisons between low and high elevations; it currently inhabits mesic habitats which occurred at a lower

  16. The Palos Verdes Fault offshore southern California: late Pleistocene to present tectonic geomorphology, seascape evolution and slip rate estimate based on AUV and ROV surveys

    Science.gov (United States)

    Brothers, Daniel S.; Conrad, James E.; Maier, Katherine L.; Paull, Charles K.; McGann, Mary L.; Caress, David W.

    2015-01-01

    The Palos Verdes Fault (PVF) is one of few active faults in Southern California that crosses the shoreline and can be studied using both terrestrial and subaqueous methodologies. To characterize the near-seafloor fault morphology, tectonic influences on continental slope sedimentary processes and late Pleistocene to present slip rate, a grid of high-resolution multibeam bathymetric data, and chirp subbottom profiles were acquired with an autonomous underwater vehicle (AUV) along the main trace of PVF in water depths between 250 and 600 m. Radiocarbon dates were obtained from vibracores collected using a remotely operated vehicle (ROV) and ship-based gravity cores. The PVF is expressed as a well-defined seafloor lineation marked by subtle along-strike bends. Right-stepping transtensional bends exert first-order control on sediment flow dynamics and the spatial distribution of Holocene depocenters; deformed strata within a small pull-apart basin record punctuated growth faulting associated with at least three Holocene surface ruptures. An upper (shallower) landslide scarp, a buried sedimentary mound, and a deeper scarp have been right-laterally offset across the PVF by 55 ± 5, 52 ± 4 , and 39 ± 8 m, respectively. The ages of the upper scarp and buried mound are approximately 31 ka; the age of the deeper scarp is bracketed to 17–24 ka. These three piercing points bracket the late Pleistocene to present slip rate to 1.3–2.8 mm/yr and provide a best estimate of 1.6–1.9 mm/yr. The deformation observed along the PVF is characteristic of strike-slip faulting and accounts for 20–30% of the total right-lateral slip budget accommodated offshore Southern California.

  17. Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of Southern California: implications for understanding the paleoenvironment of the Late Pleistocene.

    Science.gov (United States)

    Holden, Anna R; Koch, Jonathan B; Griswold, Terry; Erwin, Diane M; Hall, Justin

    2014-01-01

    The Rancho La Brea Tar Pits is the world's richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironemental indicators due to their narrow climate restrictions and life cycles. Our goal was to examine fossil material that included insect-plant associations, and thus an even higher potential for significant paleoenviromental data. Micro-CT scans of two exceptionally preserved leafcutter bee nest cells from the Rancho La Brea Tar Pits in Los Angeles, California reveal intact pupae dated between ∼23,000-40,000 radiocarbon years BP. Here identified as best matched to Megachile (Litomegachile) gentilis Cresson (Hymenoptera: Megachilidae) based on environmental niche models as well as morphometrics, the nest cells (LACMRLP 388E) document rare preservation and life-stage. The result of complex plant-insect interactions, they offer new insights into the environment of the Late Pleistocene in southern California. The remarkable preservation of the nest cells suggests they were assembled and nested in the ground where they were excavated. The four different types of dicotyledonous leaves used to construct the cells were likely collected in close proximity to the nest and infer a wooded or riparian habitat with sufficient pollen sources for larval provisions. LACMRLP 388E is the first record of fossil Megachile Latreille cells with pupae. Consequently, it provides a pre-modern age location for a Nearctic group, whose phylogenetic relationships and biogeographic history remain poorly understood. Megachile gentilis appears to respond to climate change as it has expanded its distribution across elevation gradients over time as estimated by habitat suitability comparisons between low and high elevations; it currently inhabits mesic habitats which occurred at a lower elevation during

  18. Starting lithium prophylaxis early v. late in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2014-01-01

    BACKGROUND: No study has investigated when preventive treatment with lithium should be initiated in bipolar disorder. AIMS: To compare response rates among patients with bipolar disorder starting treatment with lithium early v. late. METHOD: Nationwide registers were used to identify all patients...... with a diagnosis of bipolar disorder in psychiatric hospital settings who were prescribed lithium during the period 1995-2012 in Denmark (n = 4714). Lithium responders were defined as patients who, following a stabilisation lithium start-up period of 6 months, continued lithium monotherapy without being admitted...... to hospital. Early v. late intervention was defined in two ways: (a) start of lithium following first contact; and (b) start of lithium following a diagnosis of a single manic/mixed episode. RESULTS: Regardless of the definition used, patients who started lithium early had significantly decreased rates of non...

  19. Tectonic and sedimentary evolution of the late Miocene-Pleistocene Dali Basin in the southeast margin of the Tibetan Plateau : Evidences from anisotropy of magnetic susceptibility and rock magnetic data

    NARCIS (Netherlands)

    Li, Shihu; Deng, Chenglong; Paterson, Greig A.; Yao, Haitao; Huang, Sheng; Liu, Chengying; He, Huaiyu; Pan, Yongxin; Zhu, Rixiang

    2014-01-01

    The Cenozoic Dali Basin, located at the northeast of Diancang Shan and south of the first bend of Yangtze River, is tectonically controlled by the Dali fault system in the southeast margin of the Tibetan Plateau. The basin is filled with late Miocene to Pleistocene fluviolacustrine sediments, which

  20. Sweet vernal grasses (Anthoxanthum) colonized African mountains along two fronts in the Late Pliocene, followed by secondary contact, polyploidization and local extinction in the Pleistocene.

    Science.gov (United States)

    Tusiime, Felly Mugizi; Gizaw, Abel; Wondimu, Tigist; Masao, Catherine Aloyce; Abdi, Ahmed Abdikadir; Muwanika, Vincent; Trávníček, Pavel; Nemomissa, Sileshi; Popp, Magnus; Eilu, Gerald; Brochmann, Christian; Pimentel, Manuel

    2017-07-01

    High tropical mountains harbour remarkable and fragmented biodiversity thought to a large degree to have been shaped by multiple dispersals of cold-adapted lineages from remote areas. Few dated phylogenetic/phylogeographic analyses are however available. Here, we address the hypotheses that the sub-Saharan African sweet vernal grasses have a dual colonization history and that lineages of independent origins have established secondary contact. We carried out rangewide sampling across the eastern African high mountains, inferred dated phylogenies from nuclear ribosomal and plastid DNA using Bayesian methods, and performed flow cytometry and AFLP (amplified fragment length polymorphism) analyses. We inferred a single Late Pliocene western Eurasian origin of the eastern African taxa, whose high-ploid populations in one mountain group formed a distinct phylogeographic group and carried plastids that diverged from those of the currently allopatric southern African lineage in the Mid- to Late Pleistocene. We show that Anthoxanthum has an intriguing history in sub-Saharan Africa, including Late Pliocene colonization from southeast and north, followed by secondary contact, hybridization, allopolyploidization and local extinction during one of the last glacial cycles. Our results add to a growing body of evidence showing that isolated tropical high mountain habitats have a dynamic recent history involving niche conservatism and recruitment from remote sources, repeated dispersals, diversification, hybridization and local extinction. © 2017 John Wiley & Sons Ltd.

  1. K-Ar Geochronology and isotopic composition of the late oligocene- early miocene Ancud volcanic complex, Chiloe

    International Nuclear Information System (INIS)

    Munoz B, Jorge; Duhart O, Paul; Farmer, G. Lang; Stern, Charles R

    2001-01-01

    The Ancud Volcanic Complex (Gally and Sanchez , 1960) forms a portion of the Mid-Tertiary Coastal Magmatic Belt which outcrops in the area of northern Chiloe island. Main exposures occur at Ancud, Punta Polocue, Punihuil, Pumillahue, Tetas de Teguaco and Bahia Cocotue. The Ancud Volcanic Complex consists of basaltic to basaltic andesites lava flows and volcanic necks and rhyolitic pyroclastic flows and vitric domes. Previous studies indicate a Late Oligocene-Early Miocene age (Garcia et al., 1988; Stern and Vergara, 1992; Munoz et al., 2000). The Ancud Volcanic Complex covers and intrudes Palaeozoic-Triassic metamorphic rocks and is partially covered by an early to middle Miocene marine sedimentary sequence known as Lacui Formation (Valenzuela, 1982) and by Pleistocene glacial deposits (Heusser, 1990). At Punihuil locality, lava flows are interbedded with the lower part of the marine sedimentary sequence, which includes significant amounts of redeposited pyroclastic components. Locally, the presence of hyaloclastic breccias suggests interaction of magma with marine water (au)

  2. Lymphoscintigraphy and breast cancer: early and/or late image?

    International Nuclear Information System (INIS)

    Rousseau, C.; Campion, L.; Curtet, C.; Classe, J.M.; Dravet, F.; Fiche, M.; Sagan, C.; Chatal, J.F.; Resche, I.

    2001-01-01

    As the performance of early (H+1 to 4) and late (D1) lympho-scintigraphic images raises organisational problems in outpatient surgery for breast cancer, only early images are generally obtained. The present study evaluated whether two series of images are better than one and defined the advantages of both methodologies On hundred and eighteen patients with infiltrating breast carcinoma (T0, T1 and T2) were included in the study : 87 in group A (early and late images) and 31 in group B (only early images). All patients received two peritumoral injections of 99m Tc-sulphur colloid: 15-18 MBq (group A) and < 15 MBq (group B). During the operation, the patent blue technique was associated with radioactivity detection. The two groups were comparable for histological type and tumour size and localization. Successful localisation of sentinel-nodes on early lympho-scintigraphic images was significantly greater for group B. The sensitivity of early lymphoscintigraphy increased by 10% during the study. Sentinel node detection by the isotopic method alone or the two methods combined was comparable for both groups. In radioactivity detection, the count rate for sentinel nodes versus background (contralateral breast) was superposable for the two groups. During the learning phase, two series of images gave a definite advantage. Subsequently, lymphoscintigraphy performed at + 2 h was sufficient (the results for the two groups became superposable). (author)

  3. Leaf wax biomarker reconstruction of Early Pleistocene hydrological variation during hominin evolution in West Turkana, Kenya

    Science.gov (United States)

    Lupien, R.; Russell, J. M.; Cohen, A. S.; Feibel, C. S.; Beck, C.; Castañeda, I. S.

    2016-12-01

    Climate change is thought to play a critical role in human evolution; however, this hypothesis is difficult to test due to a lack of long, high-quality paleoclimate records from key hominin fossil locales. To address this issue, we examine Plio-Pleistocene lake sediment drill cores from East Africa that were recovered by the Hominin Sites and Paleolakes Drilling Project, an international effort to study the environment in which our hominin ancestors evolved and dispersed. With new data we test various evolutionary hypotheses, such as the "variability selection" hypothesis, which posits that high-frequency environmental variations selected for generalist traits that allowed hominins to expand into variable environments. We analyzed organic geochemical signals of climate in lake cores from West Turkana, Kenya, which span 1.87-1.38 Ma and contain the first fossils from Homo erectus. In particular, we present a compound-specific hydrogen isotopic analysis of terrestrial plant waxes (δDwax) that records regional hydrology. The amount effect dominates water isotope fractionation in the tropics; therefore, these data are interpreted to reflect mean annual rainfall, which affects vegetation structure and thus, hominin habitats. The canonical view of East Africa is that climate became drier and increasingly felt high-latitude glacial-interglacial cycles during the Plio-Pleistocene. However, the drying trend seen in some records is not evident in Turkana δDwax, signifying instead a climate with a steady mean state. Spectral and moving variance analyses indicate paleohydrological variations related to both high-latitude glaciation (41 ky cycle) and local insolation-forced monsoons (21 ky cycle). An interval of particularly high-amplitude rainfall variation occurs at 1.7 Ma, which coincides with the intensification of the Walker Circulation. These results identify high- and low-latitude controls on East African paleohydrology during Homo erectus evolution. In particular, the

  4. Systematics and paleobiogeography of .i.Sardolagus obscurus./i. n. gen. n. sp. (Leporidae, Lagomorpha) from the early Pleistocene of Sardinia

    Czech Academy of Sciences Publication Activity Database

    Angelone, Ch.; Čermák, Stanislav; Moncunill-Solé, B.; Quintana, J.; Tuveri, C.; Arca, M.; Kotsakis, T.

    2018-01-01

    Roč. 92, č. 3 (2018) ISSN 0022-3360 Institutional support: RVO:67985831 Keywords : Sardolagus obscurus n. gen. n. sp. * Leporidae * early Pleistocene * Sardinia * systematics Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Paleontology Impact factor: 1.591, year: 2016

  5. Brain size and encephalization in early to Mid-Pleistocene Homo.

    Science.gov (United States)

    Rightmire, G Philip

    2004-06-01

    Important changes in the brain have occurred during the course of human evolution. Both absolute and relative size increases can be documented for species of Homo, culminating in the appearance of modern humans. One species that is particularly well-represented by fossil crania is Homo erectus. The mean capacity for 30 individuals is 973 cm(3). Within this group there is substantial variation, but brain size increases slightly in specimens from later time periods. Other Middle Pleistocene crania differ from those of Homo erectus. Characters of the facial skeleton, vault, and cranial base suggest that fossils from sites such as Arago Cave in France, the Sima de los Huesos in Spain, Bodo in Ethiopia, Broken Hill in Zambia, and perhaps Dali in China belong to the taxon Homo heidelbergensis. Ten of these mid-Quaternary hominins have brains averaging 1,206 cm(3) in volume, and many fall beyond the limits of size predicted for Homo erectus of equivalent age. When orbit height is used to construct an index of relative brain size, it is apparent that the (significant) increase in volume documented for the Middle Pleistocene individuals is not simply a consequence of larger body mass. Encephalization quotient values confirm this finding. These changes in absolute and relative brain size can be taken as further corroborative evidence for a speciation event, in which Homo erectus produced a daughter lineage. It is probable that Homo heidelbergensis originated in Africa or western Eurasia and then ranged widely across the Old World. Archaeological traces indicate that these populations differed in their technology and behavior from earlier hominins. Copyright 2003 Wiley-Liss, Inc.

  6. HANDICRAFT IN LATE BRONZE-EARLY IRON AGE IN NAKHCHIVAN

    OpenAIRE

    Toğrul HALİLOV

    2012-01-01

    The article handicraft have been learnt in the Nakhchivan late bronze-early iron age. It was defined that pottery wasone of the ancient craftsmanship areas in Nakhichivan. At that time Nakhichivan, as well as the other regions of Azerbaijan, was an important centre of craftsmanship. The pottery products differed from one another in their size, shape, ornaments on them, the material the were made of and the technology. The pottery products made by Nakhichivan potters were divided into two grou...

  7. How do you manage early or late clock-ins? .

    Science.gov (United States)

    Marlowe, Cathy L

    2013-08-01

    My current practice has historically been very strict with hourly employees. The workday is 8:30 a.m. to 5 p.m. for most employees. They are to clock in and out at exactly those times unless overtime has been approved. (Staff working with late patients are exempt.) My business manager is constantly fighting over clock-ins 15 to 20 minutes early or late, with similar clock-outs. Staff may have a stop to make and would like to make up those 15 minutes. We do grant paid time off in an initial minimum block of 30 minutes to assist with some of this. ... The issue is not overtime, as we're well aware that we have to pay for it when appropriate. It's simply to streamline our policy and make it fair. ... I'm looking for practice policies that deal with employee variances from the 8 a.m. to 4:30 p.m. clock-ins. For example, someone wants to come in 30 minutes early in order to leave 30 minutes early for an appointment. Or someone comes in 22 minutes late due to traffic and wants either to make it up or to take the minimal half-hour paid-time-off time.

  8. Functioning in early and late stages of schizophrenia

    Directory of Open Access Journals (Sweden)

    Leonardo Gazzi Costa

    2014-12-01

    Full Text Available INTRODUCTION: Schizophrenia is frequently associated with a debilitating course and prominent impairment in social and occupational functioning. Although the criteria for classification into stages have not been defined in the literature, illness duration and functioning seem to be good candidates.OBJECTIVE:To compare functioning of patients with schizophrenia at different stages of the disease (early vs. late and healthy sex- and age-matched controls.METHODS: This double-blinded, case-controlled study included 79 individuals: 23 patients with schizophrenia diagnosed up to 5 years earlier; 19 patients with schizophrenia diagnosed at least 20 years earlier; and healthy matched controls. Diagnoses were established using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV Axis I Disorder. Functioning was assessed using the Functioning Assessment Short Test (FAST.RESULTS: Patients in the early stage had significantly higher scores than healthy controls in total FAST and in autonomy, occupational functioning, cognitive functioning and interpersonal relationships. Individuals in the late stage had significantly poorer functioning than controls in all domains. The comparison of functioning between the two groups of patients revealed no significant differences, except in occupational functioning, in which late stage patients had a poorer performance.CONCLUSION: Functioning impairment in schizophrenia tends to remain stable despite illness duration. Therefore, functioning should be effectively assessed at an early stage, as illness duration alone may not be the most reliable criterion to stage patients with schizophrenia.

  9. Early and late surgical site infections in ear surgery.

    Science.gov (United States)

    Bastier, P L; Leroyer, C; Lashéras, A; Rogues, A-M; Darrouzet, V; Franco-Vidal, V

    2016-04-01

    A retroauricular approach is routinely used for treating chronic otitis media. The incidence of surgical site infections after ear surgery is around 10% in contaminated or dirty procedures. This observational prospective study describes surgical site infections after chronic otitis media surgery with the retroauricular approach and investigated their potential predictive factors. This observational prospective study included patients suffering from chronic otitis media and eligible for therapeutic surgery with a retroauricular approach. During follow-up, surgical site infections were defined as "early" if occurring within 30 days after surgery or as "late" if occurring thereafter. The data of 102 patients were analysed. Concerning early surgical site infections, four cases were diagnosed (3.9%) and a significant association was found with preoperative antibiotic therapy, wet ear at pre-operative examination, class III (contaminated) in the surgical wound classification, NNIS (National Nosocomial Infection Surveillance) index > 1, and oral post-operative antibiotic use. Seven late surgical site infections were diagnosed (7.1%) between 90 and 160 days after surgery and were significantly correlated to otorrhoea during the 6 months before surgery, surgery duration ≤60 minutes, canal wall down technique and use of fibrin glue. Surgical site infections after chronic otitis media surgery seem to be associated with factors related to the inflammatory state of the middle ear at the time of surgery in early infections and with chronic inflammation in late infections. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

  10. Bottom water production variability in the Ross Sea slope during the Late-Pleistocene-Holocene as revealed by benthic foraminifera and sediment geochemistry

    Science.gov (United States)

    Asioli, A.; Langone, L.; Tateo, F.; Giannossi, M. L.; Giglio, F.; Summa, V.; Piva, A.; Ridente, D.; Trincardi, F.

    2009-04-01

    The Antarctic area produces bottom waters that ventilate the vast majority of the deep basins in the rest of the world ocean. The rate of formation in the source area and the strength of these cold bottom waters affect their flow toward the equator and are key factors affecting the Global Thermohaline Circulation during modern and past climate conditions. We present the results of a multidisciplinary study carried out on a core collected in 2377m of water depth on the slope off the Drygalski Basin (Ross Sea), along the modern path of the bottom waters. The goal of this research is to detect a qualitative signal of possible changes in the rate of bottom water production during the Late Pleistocene-Holocene by integrating micropaleontological and geochemical proxies. The micropaleontological signal is represented by the quantitative and qualitative variations of the agglutinated benthic foraminifera assemblages, while the amount of TOC, nitrogen, δ13C, δ15N, biogenic silica, CaCO3 in the sediment, along with the bulk rock mineralogy, provide information on the paleoproductivity and allow reconstruction of changes in the paleocirculation. The chronology is supported by 14C AMS datings on organic matter. Although this study is still in progress, the results obtained allow the following observations: 1) the Holocene sequence includes a major turnover around 8-8.5 calib kyr BP, leading to reduced nutrient utilization, probably reflecting an increased nutrient supply induced by an enhanced Upper Circumpolar Deep Water upwelling; 2) within this general context, the total concentration of benthic foraminifera preserved in the fossil component records millennial scale cycles of variable amplitude after 8.5 calib kyr BP and to present time. This oscillatory trend is paralleled by other parameters, such as the magnetic susceptibility, the dry density, the sheet silicates and the δ15N; 3) minima in foraminifera concentration reflect relatively increased dissolution, weaker

  11. Steppe lion remains imported by Ice Age spotted hyenas into the Late Pleistocene Perick Caves hyena den in northern Germany

    Science.gov (United States)

    Diedrich, Cajus G.

    2009-05-01

    Upper Pleistocene remains of the Ice Age steppe lion Panthera leo spelaea (Goldfuss, 1810) have been found in the Perick Caves, Sauerland Karst, NW Germany. Bones from many hyenas and their imported prey dating from the Lower to Middle Weichselian have also been recovered from the Perick Cave hyena den. These are commonly cracked or exhibit deep chew marks. The absence of lion cub bones, in contrast to hyena and cave bear cub remains in the Perick Caves, and other caves of northern Germany, excludes the possibility that P. leo spelaea used the cave for raising cubs. Only in the Wilhelms Cave was a single skeleton of a cub found in a hyena den. Evidence of the chewing, nibbling and cracking of lion bones and crania must have resulted from the importation and destruction of lion carcasses (4% of the prey fauna). Similar evidence was preserved at other hyena den caves and open air sites in Germany. The bone material from the Perick and other Central European caves points to antagonistic hyena and lion conflicts, similar to clashes of their modern African relatives.

  12. East-west genetic differentiation in Musk Ducks (Biziura lobata) of Australia suggests late Pleistocene divergence at the Nullarbor Plain

    Science.gov (United States)

    Guay, P.-J.; Chesser, R.T.; Mulder, R.A.; Afton, A.D.; Paton, D.C.; McCracken, K.G.

    2010-01-01

    Musk Ducks (Biziura lobata) are endemic to Australia and occur as two geographically isolated populations separated by the Nullarbor Plain, a vast arid region in southern Australia. We studied genetic variation in Musk Duck populations at coarse (eastern versus western Australia) and fine scales (four sites within eastern Australia). We found significant genetic structure between eastern and western Australia in the mtDNA control region (??ST = 0. 747), one nuclear intron (??ST = 0.193) and eight microsatellite loci (FST = 0.035). In contrast, there was little genetic structure between Kangaroo Island and adjacent mainland regions within eastern Australia. One small population of Musk Ducks in Victoria (Lake Wendouree) differed from both Kangaroo Island and the remainder of mainland eastern Australia, possibly due to genetic drift exacerbated by inbreeding and small population size. The observed low pairwise distance between the eastern and western mtDNA lineages (0.36%) suggests that they diverged near the end of the Pleistocene, a period characterised by frequent shifts between wet and arid conditions in central Australia. Our genetic results corroborate the display call divergence and Mathews' (Austral Avian Record 2:83-107, 1914) subspecies classification, and confirm that eastern and western populations of Musk Duck are currently isolated from each other. ?? 2010 Springer Science+Business Media B.V.

  13. 230Th/234U dates of late Pleistocene corals from Kita- and Minami-Diato Island, Okinawa, Japan

    International Nuclear Information System (INIS)

    Omura, Akio; Iwata, Hideki; Ota, Yoko; Koba, Motoharu; Kawana, Toshio.

    1991-01-01

    Alpha spectrometric Th-230/U-234 dating was applied to 50 Pleistocene corals from Kita- and Minami-Daito Islands, both have been well known as the noteworthy representatives of raised atolls. The Th-230/U-234 dates ranged from 113±6 to 133±6 ka (123±1 ka on average) in the autochthonous corals from Kita-, and from 111±5 to 159±10 ka (123±1 ka on average) in those from Minami-Daito Island, intimating that the fringing reefs have been developed during the high sea level stand of the last interglacial maximum. These dates are correlative to the oxygen isotope stage 5e. The upper limit of occurrence of the dated autochthonous corals was 8.1 m in Kita- and 11 m in Minami-Daito Island. Besides, the somewhat younger dates corresponding to OIS-5a or 5c were obtained from some allochthonous corals in a detrital limestone unit in Kita-Daito Island. However, hermatypic corals were alive, forming small scale reefs in shallow sea around Kita-Daito Island. The former shoreline was proved by the presence of raised surf bench at some localities, where the dated autochthonous corals were collected. (K.I.)

  14. Early versus late traumatic cataract surgery and intraocular lens implantation.

    Science.gov (United States)

    Tabatabaei, S A; Rajabi, M B; Tabatabaei, S M; Soleimani, M; Rahimi, F; Yaseri, M

    2017-08-01

    PurposeTo determine the proper time for traumatic cataract surgery after open globe injuries.SettingFarabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.DesignRandomized clinical trial.Patients and methodsIn a randomized clinical trial, 30 eyes with traumatic cataract after open globe injury with IOL implantation underwent early (in the first week after the trauma) and 30 eyes underwent late cataract surgery (from the first to second month after the trauma). We excluded patients who were under 12-year-old. All patients were visited at 1 week, 4 weeks, 12 weeks, and 6 months after surgery. In each visit, patients were examined regarding visual acuity, intraocular pressure (IOP), anterior chamber inflammation, IOL position, and posterior synechiae. In addition, posterior segment evaluation and fundoscopy were performed. Intraoperative complication including posterior capsular rupture, anterior vitrectomy, and zonulysis as well as the site of IOL implantation were documented and post-operative complications including raised IOP, anterior chamber inflammation, visual axis opacity, posterior synechiae, subluxation of IOL, and IOL pigment deposition were listed.ResultsBest-corrected visual acuity 6 months after surgery was not different between the two groups. Also in early cataract surgery group, the rate of posterior capsular rupture was not significantly higher than the late surgery group (P=0.069). On the other hand, zonulysis was significantly higher in the late procedure group (P=0.039). Other complications including anterior vitrectomy, raised IOP, anterior chamber inflammation, visual axis opacity, posterior synechiae, subluxation of IOL, and IOL pigment deposition were not different in the two groups.ConclusionsEarly and late traumatic cataract surgery and IOL implantation after open globe injuries, have no significant difference regarding the post-surgical BCVA and prominent intraoperative and post-operative complications.

  15. Late pliocene-pleistocene expansion of C4 vegetation in semiarid East Asia linked to increased burning : Geology

    NARCIS (Netherlands)

    Zhou, B.; Shen, C.; Sun, W.; Bird, M.; Ma, W.; Taylor, D.; Liu, W.; Peterse, F.; Yi, W.; Zheng, H.

    2014-01-01

    Plants using the C4 photosynthetic pathway, commonly tropical and subtropical grasses, increased in abundance in East Asia during the late Cenozoic. Determining the exact timing and likely factors leading to this major vegetation change requires region-specific studies. Here variations in pyrogenic

  16. Anthropogenic Origin of Siliceous Scoria Droplets from Pleistocene and Holocene Archeaological Sites in Northern Syria

    DEFF Research Database (Denmark)

    Thy, Peter; Willcox, George; Barfod, Gry

    2015-01-01

    Siliceous scoria droplets, measuring from 1 to 10 mm, from one late Pleistocene and four early Holocene archaeological sites in northern Syria are compared to similar droplets previously suggested to be the result of a cosmic impact at the onset of the Younger Dryas global cooling event. The !ndi......Siliceous scoria droplets, measuring from 1 to 10 mm, from one late Pleistocene and four early Holocene archaeological sites in northern Syria are compared to similar droplets previously suggested to be the result of a cosmic impact at the onset of the Younger Dryas global cooling event...

  17. Pedogenic carbonate stable isotopic evidence for wooded habitat preference of early Pleistocene tool makers in the Turkana Basin.

    Science.gov (United States)

    Quinn, Rhonda L; Lepre, Christopher J; Feibel, Craig S; Wright, James D; Mortlock, Richard A; Harmand, Sonia; Brugal, Jean-Philip; Roche, Hélène

    2013-07-01

    The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ(13)CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ(13)CVPDB values of lithic archaeological sites with paleosol δ(13)CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover

  18. Preliminary Micropaleontological Investigation of a Preserved, Late Pleistocene Cypress Forest on the Northern Gulf of Mexico Inner Shelf

    Science.gov (United States)

    Truong, J. T.; DeLong, K. L.; Bentley, S. J.; Xu, K.; Harley, G. L.; Reese, A.; Gonzalez, S.; Obelcz, J.; Caporaso, A.

    2017-12-01

    Exposed at the bottom of a trough 13 km offshore Orange Beach, AL on the Gulf of Mexico (GOM) shelf in 18 m water depth are exceptionally preserved in situ bald cypress (Taxodium distichum) stumps. Preserved seeds (T. distichum, Cephalanthus occidentalis, Hibiscus lasiocarpos, Liquidambar styraciflua) discovered in core catcher samples illustrate the exceptional preservation of the site. Woody debris samples have come back radiocarbon dead with an exception to samples located in the upper peat layer with 14C ages from 37,350-41,830 years BP. Optically stimulated luminescence and 14C dates, in combination with GOM eustatic sea level curves, suggest the forest was located 30 m above the paleoshoreline. How the forest remained preserved during subaerial exposure of the continental shelf through the Last Glacial Maximum lowstand until ensuing Holocene sea level transgression remains unknown. The R/V Coastal Profiler collected 7 vibracores from the study site in 2015 and an additional 11 in 2016. A single core (DF1) contains facies identified as the Holocene Mississippi-Alabama-Florida sand sheet, a transitional facies of interbedded sand and mud, and a basal floodplain facies in which the stumps reside. This study seeks to identify the location of the Pleistocene-Holocene unconformity and to assist in stratigraphy of the area. Foraminiferal assemblages found within the transitional facies are of a shallow marine environment that suggests Holocene in age. It is hypothesized that a pulse of sea level rise during Marine Isotope Stages 3-4 caused subsequent rapid aggradation of the paleovalley system allowing for preservation through >30 kyrs of subaerial exposure. One of the ultimate goals of this study is to serve as a guide for identification of other possible sites along the gulf coast.

  19. Taphonomy and palaeoecology of the late Pleistocene to middle Holocene small mammal succession of El Harhoura 2 cave (Rabat-Témara, Morocco).

    Science.gov (United States)

    Stoetzel, Emmanuelle; Marion, Lucile; Nespoulet, Roland; El Hajraoui, Mohammed Abdeljalil; Denys, Christiane

    2011-01-01

    The relationship between local and global climatic variations and the origin and dispersal of Homo sapiens in Africa is complex, and North Africa may have played a major role in these events. In Morocco, very few studies are specifically dedicated to small fossil vertebrates, and neither taphonomic nor palaeoecological studies have been undertaken on these taxa, particularly in archaeological contexts. The late Pleistocene to middle Holocene succession of El Harhoura 2 cave, situated in the region of Témara, yields an exceptionally rich small vertebrate assemblage. We present the results of a first systematic, taphonomic, and palaeoecological study of the small mammals from Levels 1 to 8 of El Harhoura 2. The absence of bone sorting and polishing, as well as the presence of significant traces of digestion indicate that the small mammal bones were accumulated in the cave by predators and that no water transport occurred. Other traces observed on the surface of bones consist mainly of root marks and black traces (micro-organisms or more probably manganese) which affected the majority of the material. The percentage of fragmentation is very high in all stratigraphic levels, and the post-depositional breakage (geologic and anthropogenic phenomena) obscure the original breakage patterns of bones by predators. According to the ecology of the different species present in the levels of El Harhoura 2, and by taking into account possible biases highlighted by the taphonomic analysis, we reconstruct the palaeoenvironmental evolution in the region. For quantitative reconstructions we used two indices: the Taxonomic Habitat Index (THI) and the Gerbillinae/Murinae ratio. Late Pleistocene accumulations were characterised by a succession of humid (Levels 3, 4a, 6, and 8) and arid (Levels 2?, 5, and 7) periods, with more or less open landscapes, ending in an ultimate humid and wooded period during the middle Holocene (Level 1). We discuss particular limits of our results and

  20. Early versus late tracheostomy in cardiovascular intensive care patients.

    Science.gov (United States)

    Puentes, Wilfredo; Jerath, Angela; Djaiani, George; Cabrerizo Sanchez, Rosa; Wąsowicz, Marcin

    2016-01-01

    Benefits of tracheostomy have been well established. Most of the literature, refers these benefits to general intensive care population, excluding cardiac surgery or including only small number of these patients. On the other hand, there is no clear definition describing the proper time to perform the procedure and defining what are potential benefits of early compared to late tracheostomy. This retrospective cohort aims to assess the potential benefits of early tracheostomy on post-operative outcomes, length of stay and post-tracheostomy complications within cardiac surgical population. After obtaining REB approval, we conducted a retrospective chart review in a single, tertiary care institution, identifying patients who underwent tracheostomy after cardiac surgery from 1999 to 2006. Time-to-tracheostomy was defined as "early" if tracheostomy. 32 (22%) patients underwent early tracheostomy and 115 (78%) late tracheostomy. Incidence of atrial fibrillation (31.2% vs 61.7%; P = 0.003), kidney dysfunction (6.3% vs 27.2%; P=0.015) and kidney failure 18.8% vs 43.5%; P = 0.013) were lower in the early tracheostomy group. There were no differences on post tracheostomy infection or presence of acute respiratory distress syndrome. Both the ICU and hospital length of stay were significantly shorter in early tracheostomy group, 21.5 (ET) vs 36.9 (LT) days and 37.5 (ET) vs 57.6 (LT) days respectively. There were no differences in mortality between groups. There are significant benefits in reduction of postoperative morbidities with overall shorter ICU and hospital stay. These benefits may promote faster patient rehabilitation with reduced healthcare costs.

  1. Virtual reconstruction of the Early Pleistocene mandible ATD6-96 from Gran Dolina-TD6-2 (Sierra De Atapuerca, Spain).

    Science.gov (United States)

    Bermúdez de Castro, José María; Martín-Francés, Laura; Modesto-Mata, Mario; Martínez de Pinillos, Marina; Martinón-Torres, María; García-Campos, Cecilia; Carretero, José Miguel

    2016-04-01

    In this report, we present a further study of the late Early Pleistocene ATD6-96 human mandible, recovered from the TD6-2 level of the Gran Dolina cave site (Sierra de Atapuerca, northern Spain) and attributed to Homo antecessor. ATD6-96 consists of a left half of a gracile mandible of an adult individual with the premolars and molars in place that is broken at the level of the lateral incisor-canine septum. The present analysis is based on a virtual reconstruction of the whole mandible by means of computed tomography (CT). We have reconstructed the symphysis using information from a modern human sample, as well as from a wide sample composed of several Homo specimens. This research has allowed us to record new variables with taxonomic and phylogenetic interest. We have estimated the length/width index of the alveolar arcade, as well as the percentage of the arcade length with regard to the total length. The latter confirms that ATD6-96 shares with all African and Asian Homo species a primitive structural pattern, as it was established in previous studies. In constrast, the length/width index of the alveolar arcade in the H. antecessor specimen is close to the mean values of Neandertals and the Atapuerca-Sima de los Huesos hominins. H. antecessor is derived regarding the shape of the mandibular alveolar arcade within the genus Homo and points to an early divergence from contemporaneous African populations. Our results also ratify the affinities of H. antecessor with Neanderthals, although the precise relationship with this lineage needs further research. © 2015 Wiley Periodicals, Inc.

  2. Early versus late diagnosis in community-acquired bacterial meningitis

    DEFF Research Database (Denmark)

    Bodilsen, J; Brandt, C T; Sharew, A

    2018-01-01

    OBJECTIVES: To examine clinical characteristics and outcome of patients with late diagnosis of community-acquired bacterial meningitis (CABM). METHODS: We conducted a chart review of all adults with proven CABM in three centres in Denmark from 1998 through to 2014. Patients were categorized...... as early diagnosis of CABM immediately on admission, or late diagnosis if CABM was not listed in referral or admission records and neither lumbar puncture nor antibiotic therapy for meningitis was considered immediately on admission. We used modified Poisson regression analysis to compute adjusted relative...... differences (p 65 years (56/113, 50% versus 67/245, 27%), neck stiffness (35/97, 36% versus 183/234, 78%), concomitant pneumonia (26/113, 23% versus 26/245, 11%), and meningococcal meningitis (6/113, 5% versus 52/245, 21%). These variables...

  3. The morphology and distribution of submerged reefs in the Maui-Nui Complex, Hawaii: New insights into their evolution since the Early Pleistocene

    Science.gov (United States)

    Faichney, Iain D.E.; Webster, James M.; Clague, David A.; Kelley, Chris; Applegate, Bruce; Moore, James G.

    2009-01-01

    Reef drowning and backstepping have long been recognised as reef responses to sea-level rise on subsiding margins. During the Late Pleistocene (~500–14 ka) Hawaiian reefs grew in response to rapid subsidence and 120 m 100 kyr sea-level cycles, with recent work on the submerged drowned reefs around the big island of Hawaii, and in other locations from the last deglacial, providing insight into reef development under these conditions. In contrast, reefs of the Early Pleistocene (~1.8–0.8 Ma) remain largely unexplored despite developing in response to significantly different 60–70 m 41 kyr sea-level cycles. The Maui-Nui Complex (MNC — forming the islands of Maui, Molokai, Lanai and Kahoolawe), provides a natural laboratory to study reef evolution throughout this time period as recent data indicate the reefs grew from 1.1 to 0.5 Ma. We use new high resolution bathymetric and backscatter data as well as sub-bottom profiling seismic data and field observations from ROV and submersible dives to make a detailed analysis of reef morphology and structure around the MNC. We focus specifically on the south-central region of the complex that provides the best reef exposure and find that the morphology of the reefs varies both regionally and temporally within this region. Barrier and pinnacle features dominate the steeper margins in the north of the study area whilst broad backstepping of the reefs is observed in the south. Within the Au'au channel in the central region between the islands, closely spaced reef and karst morphology indicates repeated subaerial exposure. We propose that this variation in the morphology and structure of the reefs within the MNC has been controlled by three main factors; the subsidence rate of the complex, the amplitude and period of eustatic sea-level cycles, and the slope and continuity of the basement substrate. We provide a model of reef development within the MNC over the last 1.2 Ma highlighting the effect that the interaction

  4. Late Pleistocene dune-sourced alluvial fans in coastal settings: Sedimentary facies and related processes (Mallorca, Western Mediterranean)

    Science.gov (United States)

    Pomar, F.; del Valle, L.; Fornós, J. J.; Gómez-Pujol, L.

    2018-05-01

    Aeolian-alluvial sedimentary interaction results in the formation of deposits characterized by typical alluvial sedimentary structures, but is composed of conspicuous amounts of aeolian sediments. The literature on this topic is limited and most works relate more with continental aeolian dunes or fluvial dune interference with fan bodies. Furthermore, there is a lack of examples of aeolian-alluvial sedimentary interference in coastal settings. In the western Mediterranean, there are many Pleistocene alluvial fan deposits built up partly by sediment originating from coastal dunes dismantled by alluvial streams. Very often, these deposits show a continuous sedimentary sequence through which we can derive the contribution and predominance of coastal, alluvial-colluvial and aeolian processes and their controls on landscape formation. This is an outstanding feature within coastal systems since it shows marine sediments reworked and integrated within coastal dune fields by aeolian transport, and the latter built up into alluvial fan bodies. In this sense, aeolian-alluvial interaction is the geomorphic-sedimentary expression of the coexistence and overlapping of alluvial and aeolian environments resulting in deposits sharing sedimentary features from both environments. The aim of this paper is to unravel the contribution of coastal dunes in the construction of alluvial fans bodies and identify the main sedimentary facies that constitute these deposits, as well as their climatic controls. For this reason, Es Caló fan (northern Mallorca) has been selected due to its well-exposed deposits exhibiting the alternation of aeolian, alluvial and colluvial deposits. Sedimentological and stratigraphic analyses based on 33 logs and complementary analyses demonstrate that most of the facies constituting the fan body are made up completely of marine bioclastic sands. These deposits record an alluvial fan sedimentary environment characterized by sediments inputs that do not proceed

  5. HMPAO-SPECT during epileptic seizures: Early and late images

    International Nuclear Information System (INIS)

    Overbeck, B.; Gruenwald, F.; Bockisch, A.; Biersack, H.J.; Reinke, U.; Gratz, K.F.

    1990-01-01

    For presurgical evaluation of epilepsy a 44-year old patient with complex-partial seizures underwent HMPAO-SPECT. The morphology of the seizures, the MRI-scan, psychometry and ictal as well as interictal EEGs showed a left temporal origin of the seizures. Early images were obtained 20 min and late images 24 h following injection. On both scans a marked hyperperfusion was observed in the left temporal area. A crossed cerebellar diaschisis was also seen on both SPECTs. It could be shown that during ictal examinations there is no bloodflow-dependent wash-out from brain tissue. (orig.) [de

  6. Environmental change during the Late Berriasian - Early Valanginian: a prelude to the late Early Valanginian carbon-isotope event?

    Science.gov (United States)

    Morales, Chloé; Schnyder, Johann; Spangenberg, Jorge; Adatte, Thierry; Westermann, Stephane; Föllmi, Karl

    2010-05-01

    The Valanginian period is well known for a positive excursion in marine and terrestrial δ13C records, which has been interpreted as the consequence of a major perturbation in the global carbon cycle (Lini et al., 1992; Erba et al., 2004). In contrast to the positive δ13C excursions of the Early Aptian and latest Cenomanian, marine organic-rich sediments have only been recognized from a few localities (van de Schootbrugge et al., 2003; Reboulet et al., 2003; Gröcke et al., 2005; Westermann et al., in press). The δ13C excursion began in the late Early Valanginian (campylotoxus ammonite zone) and gradually ended during the Late Valanginian. It is associated with a phase of widespread carbonate-platform drowning on the shelf (Föllmi et al., 1994) and a decline in calcareous nannofossils in the pelagic realm (Erba et al., 2004). As a triggering mechanism, numerous authors invoke the formation of the Parañà-Etendeka flood basalt. The correlation of this episode with the Valanginian δ13C event depends, however, on the absolute ages attributed to the Valanginian stage. The recent geological timescale by Ogg et al. (2008) shows that the major eruptional phase occurred during the Late Valanginian. This may imply that the late Early Valanginian δ13C event resulted from a combination of different factors. Important paleoenvironmental change occurred already in the latest Berriasian and earliest Valanginian, prior to the positive δ13C excursion. An increase in nutrient input near the onset of the δ13C excursion (campylotoxus ammonite zone), which may be considered as a trigger of the carbon cycle perturbation, has been identified in different studies, (Hennig, 2003; Duchamp-Alphonse et al., 2007; Bornemann & Mutterlose, 2008). Heterozoan faunal associations became dominant since the Early Valanginian on the northern Tethyan Helvetic platform and may indicate the beginning of sea-water eutrophication (Föllmi et al., 2007). Clay assemblages in the Tethys and Western

  7. Response of alluvial systems to Late Pleistocene climate changes recorded by environmental magnetism in the Añavieja Basin (Iberian Range, NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Oliva-Urcia, B.; Muñoz, A.; Larrasoaña, J.C.; Luzon, A.; Perez, A.; Gonzalez, A.; Jiang, Z.; Liu, Q.; Roman-Berdi, T.

    2016-07-01

    Environmental magnetic proxies were analyzed in a relatively monotonous, ~25.3m thick alluvial sedimentary sequence drilled in the Añavieja Basin (NE Spain). Results from the core AÑ2 suggest that the concentrationdependent magnetic parameters mainly reflect variations in the content of detrital magnetite, sourced in the catchment rocks and soils of the basin, via changes in the dynamics of alluvial fans due to temperature changes in the northern hemisphere during the Late Pleistocene. The correspondence between the magnetic proxies and the temperature variations in the North Atlantic region (NGRIP curve) indicates that higher (lower) concentrations and finer (coarser) magnetite grains coincide with warm (cold) periods. We propose that during cold periods, a sparser vegetation cover favored the incoming of higher energy runoff bearing coarser sediments to the basin that are relatively impoverished in magnetite. In contrast, during warm periods, the wider distribution of the vegetation cover associated with the lower runoff energy lead to finer, magnetite-richer sediment input to the basin. Maghemite, presumably of pedogenic origin, appears to be present also in the studied alluvial sediments. Further studies are necessary to unravel its palaeoclimatic significance. (Author)

  8. A rhinocerotid-dominated megafauna at the MIS6-5 transition: The late Middle Pleistocene Coc Muoi assemblage, Lang Son province, Vietnam

    Science.gov (United States)

    Bacon, Anne-Marie; Antoine, Pierre-Olivier; Huong, Nguyen Thi Mai; Westaway, Kira; Tuan, Nguyen Anh; Duringer, Philippe; Zhao, Jian-xin; Ponche, Jean-Luc; Dung, Sam Canh; Nghia, Truong Huu; Minh, Tran Thi; Son, Pham Thanh; Boyon, Marc; Thuy, Nguyen Thi Kim; Blin, Amandine; Demeter, Fabrice

    2018-04-01

    Little is known about the ecosystems in the north of the Indochinese peninsula at the Middle-Late Pleistocene transition. In this paper, we analyzed the new fauna from Coc Muoi cave, Lang Son province, northeast Vietnam. In comparison with other well-documented faunas from the region, that of Coc Muoi is distinguished by the predominance of rhinoceroses among diverse large-bodied herbivores. The results of the OSL and pIR-IRSL dating of the cave sediments and U-series dating of flowstones indicate a potential age range of 148-117 ka for the fauna (MIS6-5). The analysis of age-at-death distributions of rhinoceroses, wild cattle, sambar deer, and wild pig, does not show any apparent selectivity of age classes. We also focused our study on rhinoceroses, tapirs, and wild cattle by analyzing the prevalence of hypoplastic defects on deciduous and permanent teeth, in an attempt to assess the health status of the taxa during their first years of growth. The health status of large-bodied herbivores (kouprey and rhinoceros) reveals the importance of stressors (biotic and abiotic) in the rainforest environment during a period of marked climatic transition (MIS6-5) in comparison with other MIS5-4 well-documented faunas from the region.

  9. A draft de novo genome assembly for the northern bobwhite (Colinus virginianus reveals evidence for a rapid decline in effective population size beginning in the Late Pleistocene.

    Directory of Open Access Journals (Sweden)

    Yvette A Halley

    Full Text Available Wild populations of northern bobwhites (Colinus virginianus; hereafter bobwhite have declined across nearly all of their U.S. range, and despite their importance as an experimental wildlife model for ecotoxicology studies, no bobwhite draft genome assembly currently exists. Herein, we present a bobwhite draft de novo genome assembly with annotation, comparative analyses including genome-wide analyses of divergence with the chicken (Gallus gallus and zebra finch (Taeniopygia guttata genomes, and coalescent modeling to reconstruct the demographic history of the bobwhite for comparison to other birds currently in decline (i.e., scarlet macaw; Ara macao. More than 90% of the assembled bobwhite genome was captured within 14,000 unique genes and proteins. Bobwhite analyses of divergence with the chicken and zebra finch genomes revealed many extremely conserved gene sequences, and evidence for lineage-specific divergence of noncoding regions. Coalescent models for reconstructing the demographic history of the bobwhite and the scarlet macaw provided evidence for population bottlenecks which were temporally coincident with human colonization of the New World, the late Pleistocene collapse of the megafauna, and the last glacial maximum. Demographic trends predicted for the bobwhite and the scarlet macaw also were concordant with how opposing natural selection strategies (i.e., skewness in the r-/K-selection continuum would be expected to shape genome diversity and the effective population sizes in these species, which is directly relevant to future conservation efforts.

  10. Errors in the Production of Adult Early and Late Bilinguals

    Directory of Open Access Journals (Sweden)

    Teresa Lee

    2014-08-01

    Full Text Available This study examines the grammatical knowledge of adult second language (L2 learners and heritage speakers. Given the differences in the mode and age of acquisition between L2 learners (late bilinguals and heritage speakers (early bilinguals, the question arises as to whether and how these groups differ from each other in their knowledge of Korean. To address this question, the present study looks at the production of Korean relative clauses by three groups of learners (26 L2 learners, 11 simultaneous bilinguals, and 38 early sequential bilinguals. The results of a written production task showed that all three groups made similar types of errors such as those involving the use of incorrect word order and case markers. Yet differences were also observed in the nature of errors made by these three groups. Based on the findings, pedagogical implications are drawn for classroom instruction.

  11. Are osseous artefacts a window to perishable material culture? Implications of an unusually complex bone tool from the Late Pleistocene of East Timor.

    Science.gov (United States)

    O'Connor, S; Robertson, G; Aplin, K P

    2014-02-01

    We report the discovery of an unusually complex and regionally unique bone artefact in a Late Pleistocene archaeological assemblage (c. 35 ka [thousands of years ago]) from the site of Matja Kuru 2 on the island of Timor, in Wallacea. The artefact is interpreted as the broken butt of a formerly hafted projectile point, and it preserves evidence of a complex hafting mechanism including insertion into a shaped or split shaft, a complex pattern of binding including lateral stabilization of the cordage within a bilateral series of notches, and the application of mastic at several stages in the hafting process. The artefact provides the earliest direct evidence for the use of this combination of hafting technologies in the wider region of Southeast Asia, Wallacea, Melanesia and Australasia, and is morphologically unparallelled in deposits of any age. By contrast, it bears a close morphological resemblance to certain bone artefacts from the Middle Stone Age of Africa and South Asia. Examination of ethnographic projectile technology from the region of Melanesia and Australasia shows that all of the technological elements observed in the Matja Kuru 2 artefact were in use historically in the region, including the unusual feature of bilateral notching to stabilize a hafted point. This artefact challenges the notion that complex bone-working and hafting technologies were a relatively late innovation in this part of the world. Moreover, its regional uniqueness encourages us to abandon the perception of bone artefacts as a discrete class of material culture, and to adopt a new interpretative framework in which they are treated as manifestations of a more general class of artefacts that more typically were produced on perishable raw materials including wood. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  12. Quartz and K-feldspar luminescence dating of sedimentation in the North Bohai coastal area (NE China) since the late pleistocene

    Science.gov (United States)

    Li, Yan; Shang, Zhiwen; Tsukamoto, Sumiko; Tamura, Toru; Yi, Liang; Wang, Hong; Frechen, Manfred; Li, Jianfen; Jiang, Xingyu

    2018-02-01

    In this study, luminescence dating of core sediments from the North Bohai Coast (China) was applied to provide a high-resolution chronological constraint, on a better understanding of the Holocene marine-terrestrial interaction. The studied sedimentary sequence contains a terrigenous deposit, a transgressive deposit and a prograding deltaic succession; all are believed to have formed during the late Pleistocene. To establish a reliable luminescence chronology, the luminescence signals of ten samples were investigated in order to quantify the degree of bleaching. This approach involved the use of quartz OSL, K-feldspar infrared stimulated luminescence (IRSL) and post-IR IRSL (pIRIR) ages. The resulting data were then compared with radiocarbon ages. The quartz OSL signals were well-bleached for all the samples, and the feldspar pIRIR150 and pIRIR225 signals yielded reliable ages for the pre-Holocene deposits but overestimated ages for late Holocene deposits (input. Rapid deltaic progradation with high sedimentation rates over the last millennia, was revealed by the quartz OSL age results. This was supported by historical records for this section of the coastline. Episodic deposition around 700 years ago most likely triggered by frequent flooding events, was highlighted by the clustered OSL ages. While the sediment increment was 2.7 × 104 m3 a-1 for the period of ∼6-1 ka, this increased considerably to 9.1 × 106 m3 a-1 during the rapid progradation of the last millennium. The increase appears related to winter monsoon enhancement and human activity during the last 1000 years.

  13. Comparison of Geochemical, Grain-Size, and Magnetic Proxies for Rock Flour and Ice- Rafted Debris in the Late Pleistocene Mono Basin, CA

    Science.gov (United States)

    Zimmerman, S. H.; Hemming, S. R.; Kent, D. V.

    2008-12-01

    Advance and retreat of mountain glaciers are important indicators of climate variability, but the most direct proxy record, mapping and dating of moraines, is by nature discontinous. The Sierra Nevada form the western boundary of the Mono Lake basin, and the proximity of the large Pleistocene lake to the glacial canyons of the Sierra presents a rare opportunity to examine glacial variability in a continuous, well-dated lacustrine sequence. We have applied a geochemical proxy for rock flour to the glacial silts of the late Pleistocene Wilson Creek Formation, but because it is time- and sample-intensive, another method is required for a high-resolution record. Previous microscopic examination, thermomagnetic measurements, XRD analysis, and new isothermal remnant magnetization (IRM) acquisition curves show that the magnetic mineralogy is dominated by fine-grained, unaltered magnetite. Bulk measurements show strong susceptibility (mean ~ 16 x 10- 6 m3/kg) and remanent magnetization (mean IRM ~ 10-2 Am2/kg) compared to diluting components (carbonate, smectite, rhyolitic ash). The Wilson Creek type section sediments also contain a coarse lithic fraction, quantified by counting the >2cm clasts in outcrop and the >425 μm fraction in the bulk sediment. Susceptibility, IRM, and ARM (anhysteretic remnant magnetization) are quite similar throughout the type section, with the abundance of coarse lithic fraction correlative to the ratio k/IRM. Because the magnetic fraction of the rock flour is fine-grained magnetite, IRM should capture the changes in concentration of flour through time, and the major features of the (low-resolution) geochemical flour proxy record are identifiable in the IRM record. Flux-correction of the IRM results in a rock flour proxy record with major peaks between 36 and 48 ka, similar to a rock flour record from neighboring Owens Lake. This regional glacial signal contrasts with peaks in coarse lithics between 58 and 68 ka in the Wilson Creek record

  14. Geothermal properties and groundwater flow estimated with a three-dimensional geological model in a late Pleistocene terrace area, central Japan

    Science.gov (United States)

    Funabiki, A.; Takemura, T.; Hamamoto, S.; Komatsu, T.

    2012-12-01

    1. Introduction The ground source heat pump (GSHP) is a highly efficient and renewable energy technology for space heating and cooling, with benefits that include energy conservation and reductions in greenhouse gas emissions. One result of the huge Tohoku-oki earthquake and tsunami and the subsequent nuclear disasters is that GSHPs are receiving more attention from the media and they are being introduced by some local governments. Heat generated by underground GSHP installation, however, can pollute the geothermal environment or change groundwater flow patterns . In this study, we estimated possible effects from the use of GSHPs in the Tokyo area with a three-dimensional (3D) geological model. 2. Geological model The Tokyo Metropolitan Area is surrounded by the Late Pleistocene terraces called the Musashino uplands. The terrace surfaces are densely populated residential areas. One of these surfaces, the Shimosueyohi surface, formed along the Tama River during the last deglacial period. The CRE-NUCHS-1 core (Funabiki et al., 2011) was obtained from this surface, and the lithology, heat transfer coefficients, and chemical characteristics of the sediments were analyzed. In this study, we used borehole log data from a 5 km2 area surrounding the CRE-NUCHS-1 core site to create a 3D geological model. In this area, the Pleistocene Kazusa Group is overlain by terrace gravels and a volcanic ash layer called the Kanto Loam. The terrace gravels occur mainly beneath the Kanda, Kitazawa, and Karasuyama rivers , which flow parallel to the Tama River, whereas away from the rivers , the Kanto Loam directly overlies the Kazusa Group sediments. 3. Geothermal disturbance and groundwater flow Using the geological model, we calculated the heat transfer coefficients and groundwater flow velocities in the sediments. Within the thick terrace gravels, which are at relatively shallow depth (8-20 m), heat transfer coefficients were high and groundwater flow was relatively fast. The amount

  15. Middle to Late Pleistocene multi-proxy record of environmental response to climate change from the Vienna Basin, Central Europe (Austria)

    Science.gov (United States)

    Salcher, Bernhard C.; Frank-Fellner, Christa; Lomax, Johanna; Preusser, Frank; Ottner, Franz; Scholger, Robert; Wagreich, Michael

    2017-10-01

    Tectonic basins can represent valuable archives of the environmental history. Presented here are the stratigraphy and multi-proxy analyses of two adjacent alluvial fans in the Quaternary active parts of the Vienna Basin, situated at the interface of the Atlantic, European continental and Mediterranean climate. Deposits comprise a sequence of coarse-grained fluvial deposits intercalated by laterally extensive horizons of pedogenically altered fine sediments. To establish palaeoenvironmental reconstructions, fine-grained sequences from a drill core and outcrop data were analysed according to its malacofauna, palaeopedology, susceptibility and sedimentology. The chronological framework is provided by 38 luminescence ages and supported by geomagnetic polarity investigations. Distinct warm periods each associated with a geomagnetic excursion, are recorded in three pedocomplexes formed during the Last Interglacial and two earlier interglacial periods, indicted to correlate with Marine Isotope Stage (MIS) 9 and MIS 11, respectively. Environmental conditions during the early last glacial period (MIS 5, c. 100-70 ka) are reconstructed from mollusc-shell rich overbank fines deposited along a former channel belt, covered by massive sheetflood deposits during MIS 2. Analysed warm phases suggest strong variations in humidity, ranging from steppe to forest dominated environments. The study presents one of the few numerically dated Middle Pleistocene multi-proxy records and one of the most comprehensive malacological datasets covering the early phases of last glacial period of continental Europe.

  16. Early versus late initiation of epidural analgesia for labour.

    Science.gov (United States)

    Sng, Ban Leong; Leong, Wan Ling; Zeng, Yanzhi; Siddiqui, Fahad Javaid; Assam, Pryseley N; Lim, Yvonne; Chan, Edwin S Y; Sia, Alex T

    2014-10-09

    Pain during childbirth is arguably the most severe pain some women may experience in their lifetime. Epidural analgesia is an effective form of pain relief during labour. Many women have concerns regarding its safety. Furthermore, epidural services and anaesthetic support may not be available consistently across all centres. Observational data suggest that early initiation of epidural may be associated with an increased risk of caesarean section, but the same findings were not seen in recent randomised controlled trials. More recent guidelines suggest that in the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labour. The choice of analgesic technique, agent, and dosage is based on many factors, including patient preference, medical status, and contraindications. There is no systematically reviewed evidence on the maternal and foetal outcomes and safety of this practice. This systematic review aimed to summarise the effectiveness and safety of early initiation versus late initiation of epidural analgesia in women. We considered the obstetric and fetal outcomes relevant to women and side effects of the treatments, including risk of caesarean section, instrumental birth and time to birth. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (12 February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (January 1966 to February 2014), Embase (January 1980 to February 2014) and reference lists of retrieved studies. We included all randomised controlled trials involving women undergoing epidural labour analgesia that compared early initiation versus late initiation of epidural labour analgesia. Two review authors independently assessed trials for inclusion, extracted the data and assessed the trial quality. Data were checked for accuracy. We included nine studies with a total of 15,752 women.The overall risk of bias of

  17. Reconstruction of Equilibrium Line Altitudes of Nevado Coropuna Glaciers (Southern Peru) from the Late Pleistocene to the present

    Science.gov (United States)

    Úbeda, J.; Palacios, D.; Vázquez, L.

    2009-04-01

    The Nevado Coropuna (15°31'S-72°39'W) is a volcanic complex located 200 km NE of the city of Arequipa, in the Southern Peruvian Andes. The summit area in the complex is covered with a glacier system formed by dozens of branches descending in all directions totaling many km2 in surface area. The study of the volcanic complex and its glaciers is of great interest because it is the main water reserve for tens of thousands of people, because of the risk scenario created by the presence of ice masses on a volcano with relatively recent activity, and because it constitutes an excellent geoindicator of the effects of climate change on ice masses in the western mountain chain of the Central Andes. This research aims to analyze glacier evolution using as geoindicators variations in glacier surface and equilibrium line altitudes (ELAs), defining deglaciation rates based on those variations and preparing forecasts with them on when the ice masses might disappear if the same rates were to occur in the future. In addition, a first estimation is attempted of the chronologies of the last phase of volcanic activity and the last phase of maximum glacier advance that can be attributed to the Late Glacial or Last Glacial Maximum periods. To achieve these aims, digital topography with 50m contour interval, two orthophotos of the central section of the Coropuna complex (15-6-1955 and 21-10-1986), an ASTER satellite image (12-11-2007) and geomorphological mapping of the volcanic complex created in a previous phase of the research (Ubeda, 2007) were integrated into a Geographical Information System (GIS). The GIS was used to determine the global extent of the glacier system, and in more detail, that of two groups (NE and SE) in 1955, 1986 and 2007. Using the geomorphological cartography as a basis, the extent of the glaciers during their last advance in the Little Ice Age (LIA) and their last maximum advance were calculated. Next, surface areas for all phases were calculated using

  18. Before the Emergence of Homo sapiens: Overview on the Early-to-Middle Pleistocene Fossil Record (with a Proposal about Homo heidelbergensis at the subspecific level)

    Science.gov (United States)

    Manzi, Giorgio

    2011-01-01

    The origin of H. sapiens has deep roots, which include two crucial nodes: (1) the emergence and diffusion of the last common ancestor of later Homo (in the Early Pleistocene) and (2) the tempo and mode of the appearance of distinct evolutionary lineages (in the Middle Pleistocene). The window between 1,000 and 500 thousand years before present appears of crucial importance, including the generation of a new and more encephalised kind of humanity, referred to by many authors as H. heidelbergensis. This species greatly diversified during the Middle Pleistocene up to the formation of new variants (i.e., incipient species) that, eventually, led to the allopatric speciation of H. neanderthalensis and H. sapiens. The special case furnished by the calvarium found near Ceprano (Italy), dated to 430–385 ka, offers the opportunity to investigate this matter from an original perspective. It is proposed to separate the hypodigm of a single, widespread, and polymorphic human taxon of the Middle Pleistocene into distinct subspecies (i.e., incipient species). The ancestral one should be H. heidelbergensis, including specimens such as Ceprano and the mandible from Mauer. PMID:21716742

  19. Facies associations, depositional environments and stratigraphic framework of the Early Miocene-Pleistocene successions of the Mukah-Balingian Area, Sarawak, Malaysia

    Science.gov (United States)

    Murtaza, Muhammad; Rahman, Abdul Hadi Abdul; Sum, Chow Weng; Konjing, Zainey

    2018-02-01

    Thirty-five stratigraphic section exposed along the Mukah-Selangau road in the Mukah-Balingian area have been studied. Sedimentological and palynological data have been integrated to gain a better insight into the depositional architecture of the area. Broadly, the Mukah-Balingian area is dominated by fluvial, floodplain and estuarine related coal-bearing deposits. The Balingian, Begrih and Liang formations have been described and interpreted in terms of seven facies association. These are: FA1 - Fluvial-dominated channel facies association; FA2 - Tide-influenced channel facies association; FA3 - Tide-dominated channel facies association; FA4 - Floodplain facies association; FA5 - Estuarine central basin-mud flats facies association; FA6 - Tidal flat facies association and FA7 - Coastal swamps and marshes facies association. The Balingian Formation is characterised by the transgressive phase in the base, followed by a regressive phase in the upper part. On the basis of the occurrence of Florscheutzia trilobata with Florscheutzia levipoli, the Early to Middle Miocene age has been assigned to the Balingian Formation. The distinct facies pattern and foraminifera species found from the samples taken from the Begrih outcrop imply deposition in the intertidal flats having pronounced fluvio-tidal interactions along the paleo-margin. Foraminiferal data combined with the pronounced occurrence of Stenochlaena laurifolia suggest at least the Late Miocene age for the Begrih Formation. The internal stratigraphic architecture of the Liang Formation is a function of a combination of sea level, stable tectonic and autogenic control. Based on stratigraphic position, the Middle Pliocene to Pleistocene age for the Liang Formation is probable. The Balingian, Begrih and Liang formations display deposits of multiple regressive-transgressive cycles while the sediments were derived from the uplifted Penian high and Rajang group.

  20. New ESR/U-series data for the early Middle Pleistocene site of Isernia la Pineta, Italy

    International Nuclear Information System (INIS)

    Shao Qingfeng; Bahain, Jean-Jacques; Falgueres, Christophe; Peretto, Carlo; Arzarello, Marta; Minelli, Antonella; Thun Hohenstein, Ursula; Dolo, Jean-Michel; Garcia, Tristan; Frank, Norbert; Douville, Eric

    2011-01-01

    Located in Southern Italy, the Early Palaeolithic site of Isernia la Pineta has provided numerous palaeontological remains and artefacts in well-defined fluvio-lacustrine sequence. The normal magnetization of the main archaeological layer t3a and 39 Ar/ 40 Ar date of 610 ± 10 (2σ) ka, obtained from the immediately overlaying geological level, put the Isernia assemblage in the first part of the Middle Pleistocene. Previous ESR/U-series analyses of Isernia fossil teeth have displayed both recent U-uptake and severe underestimation of the ESR/U-series dates in comparison with the 39 Ar/ 40 Ar age. In order to identify the cause of this age underestimation, new analyses were realized in the present study on four bovid teeth directly recovered from the archaeological surface t3a. The ESR/U-series dates obtained were once again strongly underestimated, with an error weighted mean age of 435 ± 24 (1σ) ka. These too young dates could be associated to a change of the environmental γ-dose rate during the geological history of the Isernia site, related to the revealed recent U-uptake into the palaeontological remains of the archaeological level. If we consider that this dose rate change was coeval with a wet interglacial period and taking the 39 Ar/ 40 Ar age as geochronological reference, simulations with two dose rate steps indicate that this change could be correlated with marine isotopic stage 7 (MIS 7).

  1. New ESR/U-series data for the early Middle Pleistocene site of Isernia la Pineta, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Shao Qingfeng, E-mail: shao@mnhn.fr [Departement de Prehistoire du Museum National d' Histoire Naturelle, UMR 7194 CNRS, 1 rue Rene Panhard, F-75013 Paris (France); Bahain, Jean-Jacques; Falgueres, Christophe [Departement de Prehistoire du Museum National d' Histoire Naturelle, UMR 7194 CNRS, 1 rue Rene Panhard, F-75013 Paris (France); Peretto, Carlo; Arzarello, Marta; Minelli, Antonella; Thun Hohenstein, Ursula [Dipartimento di Biologia ed Evoluzione, Universita di Ferrara, C.so Ercole I d' Este 32, I-44121 Ferrara (Italy); Dolo, Jean-Michel; Garcia, Tristan [CEA, LIST, Laboratoire National Henri Becquerel, F-91191 Gif-sur-Yvette cedex (France); Frank, Norbert; Douville, Eric [Laboratoire des Sciences du Climat et de l' Environnement, LSCE/IPSL, UMR 8212 CNRS-CEA-UVSQ, Domaine du CNRS, F-91198 Gif/Yvette cedex (France)

    2011-09-15

    Located in Southern Italy, the Early Palaeolithic site of Isernia la Pineta has provided numerous palaeontological remains and artefacts in well-defined fluvio-lacustrine sequence. The normal magnetization of the main archaeological layer t3a and {sup 39}Ar/{sup 40}Ar date of 610 {+-} 10 (2{sigma}) ka, obtained from the immediately overlaying geological level, put the Isernia assemblage in the first part of the Middle Pleistocene. Previous ESR/U-series analyses of Isernia fossil teeth have displayed both recent U-uptake and severe underestimation of the ESR/U-series dates in comparison with the {sup 39}Ar/{sup 40}Ar age. In order to identify the cause of this age underestimation, new analyses were realized in the present study on four bovid teeth directly recovered from the archaeological surface t3a. The ESR/U-series dates obtained were once again strongly underestimated, with an error weighted mean age of 435 {+-} 24 (1{sigma}) ka. These too young dates could be associated to a change of the environmental {gamma}-dose rate during the geological history of the Isernia site, related to the revealed recent U-uptake into the palaeontological remains of the archaeological level. If we consider that this dose rate change was coeval with a wet interglacial period and taking the {sup 39}Ar/{sup 40}Ar age as geochronological reference, simulations with two dose rate steps indicate that this change could be correlated with marine isotopic stage 7 (MIS 7).

  2. The early and middle Pleistocene archaeological record of Greece : current status and future prospects

    NARCIS (Netherlands)

    Tourloukis, Vangelis

    2010-01-01

    By applying a fieldwork-based, geoarchaeological approach, Tourloukis examines in this study the evidence from Greece within the framework of the earliest occupation of Europe. Although the Greek Peninsula lies within a core area of early hominin movements between Africa and Europe but also within

  3. Pleistocene Palaeoart of Asia

    Directory of Open Access Journals (Sweden)

    Robert G. Bednarik

    2013-06-01

    Full Text Available This comprehensive overview considers the currently known Pleistocene palaeoart of Asia on a common basis, which suggests that the available data are entirely inadequate to form any cohesive synthesis about this corpus. In comparison to the attention lavished on the corresponding record available from Eurasia’s small western appendage, Europe, it is evident that Pleistocene palaeoart from the rest of the world has been severely neglected. Southern Asia, in particular, holds great promise for the study of early cognitive development of hominins, and yet this potential has remained almost entirely unexplored. Asia is suggested to be the key continent in any global synthesis of ‘art’ origins, emphasising the need for a comprehensive pan-continental research program. This is not just to counter-balance the incredible imbalance in favour of Europe, but to examine the topic of Middle Pleistocene palaeoart development effectively.

  4. ­Orbital-scale variations in Indo-Pacific hydroclimate during the mid- to late Pleistocene from Lake Towuti, Indonesia

    Science.gov (United States)

    Russell, J. M.; Vogel, H.; Bijaksana, S.; Melles, M.

    2016-12-01

    The Indo-Pacific region plays a critical role in the Earth's climate system. Changes in local insolation, greenhouse gas concentrations, ice volume, and local sea level are all hypothesized to exert a dominant control on Indo-Pacific hydroclimate, yet existing records from the region are generally short and exhibit fundamental differences in orbital-scale patterns that limit our understanding of the regional climate responses to orbital-scale forcings. In 2015 we conducted an ICDP drilling program on Lake Towuti, located near the equator in central Indonesia, one of the only terrestrial sedimentary archives in the region that continuously spans multiple glacial-interglacial cycles. We recovered over 1,000 meters of core including cores though the entire sediment sequence to bedrock. Previously published organic geochemical reconstructions of vegetation from relatively short, 60 kyr long piston from Lake Towuti exhibit strong drying during the Last Glacial Maximum, indicating that central Indonesian hydroclimate is sensitive to forcing from high-latitude ice-sheets. New, inorganic geochemical and mineralogical reconstructions of lake level also indicate a strong half-precessional climate signal during the last 60 kyr in which lake level highstands occur during austral and boreal summer insolation maxima, suggesting that equatorial rainfall varies in response to remote (likely subtropical) insolation forcing of the Asian monsoons. However, the short length of these records limits our understanding of the regional hydroclimatic response to the full range of global climate boundary conditions experienced during the late Quaternary. This presentation will discuss results from the last 60 kyr and present new geochemical reconstructions from the upper 100 m of core from Lake Towuti, dated using magnetic paleointensity, tephrachronology, and optically-stimulated luminescence to span the last 500 kyr BP.

  5. Fossil amphibians and reptiles from Tegelen (Province of Limburg) and the early Pleistocene palaeoclimate of The Netherlands

    Science.gov (United States)

    Villa, Andrea; Blain, Hugues-Alexandre; van den Hoek Ostende, Lars W.; Delfino, Massimo

    2018-05-01

    Few Quaternary herpetofaunas have been recovered from The Netherlands. Among these, the one coming from the early Pleistocene site of the Russel-Tiglia-Egypte pit near Tegelen is of particular interest, because it is the type locality of the recently described, last western European palaeobatrachid anuran, Palaeobatrachus eurydices. The large number of fossil remains of amphibians and reptiles found in the pit are representative of a very diverse fauna, including at least 17 taxa: Triturus gr. T. cristatus, Lissotriton sp., Pelobates fuscus, Bufo bufo, Bombina sp., Pelophylax sp., Rana sp., Hyla gr. H. arborea, Pelodytes sp., Mauremys sp., Lacerta sp., Lacertidae indet., Anguis gr. A. fragilis, cf. Pseudopus sp., "colubrines" indet., Natrix natrix and Vipera sp. Emys orbicularis, previously reported from a different Tegelen pit, is not present in this assemblage. Palaeoclimatic conditions reconstructed based on the herpetofaunistic association indicate a humid subtropical climate (Cfa according to the Köppen-Geiger classification of climates) for Tegelen during the TC5 section of the Tiglian, with low, but fairly regular rainfalls during the year. Mean annual temperature was 13.4 ± 0.3 °C and mean annual precipitation was 542 ± 50 mm. Moreover, three dry months were present during summer and early autumn, resulting in a much drier climate than the one present at Tegelen today. Nevertheless, the occurrence of the water-dwelling P. eurydices suggests the persistence of suitable permanent water bodies during the whole year, and the survival of this taxon in this part of Europe might have been allowed by the generally humid climate.

  6. Spain as an emergency air traffic hub during volcanic air fall events? Evidence of past volcanic ash air fall over Europe during the late Pleistocene

    Science.gov (United States)

    Hardiman, Mark; Lane, Christine; Blockley, Simon P. E.; Moreno, Ana; Valero-Garcés, Blas; Ortiz, José E.; Torres, Trino; Lowe, John J.; Menzies, Martin A.

    2010-05-01

    Past volcanic eruptions often leave visible ash layers in the geological record, for example in marine or lake sedimentary sequences. Recent developments, however, have shown that non-visible volcanic ash layers are also commonly preserved in sedimentary deposits. These augment the record of past volcanic events by demonstrating that past ash dispersals have been more numerous and widely disseminated in Europe than previously appreciated. The dispersal ‘footprints' of some large late Pleistocene European eruptions are examined here in the light of the recent Eyjafjallajökull eruption. For example, the Vedde Ash which was erupted from Iceland around 12 thousand years ago, delivered distal (and non-visible) glass deposits as far south as Switzerland and as far east as the Ural Mountains in Russia, with an overall European distribution remarkably similar to the dominant tracks of the recent Eyjafjallajökull plumes. The Eyjafjallajökull eruption has demonstrated that relatively small amounts of distal volcanic ash in the atmosphere can seriously disrupt aviation activity, with attendant economic and other consequences. It has raised fundamental questions about the likelihood of larger or more prolonged volcanic activity in the near future, and the possibility of even more serious consequences than those experienced recently. Given that there are several other volcanic centres that could cause such disruption in Europe (e.g. Campania and other volcanic centres in Italy; Aegean volcanoes), a key question is whether there are parts of Europe less prone to ash plumes and which could therefore operate as emergency air traffic hubs during times of ash dispersal. Although not generated to answer this question, the recent geological record might provide a basis for seeking the answer. For example, four palaeo-records covering the time frame of 8 - 40 Ka BP that are geographically distributed across Spain have been examined for non-visible distal ash content. All four have

  7. The challenge of dating Early Pleistocene fossil teeth by the combined uranium series-electron spin resonance method: the Venta Micena palaeontological site (Orce, Spain)

    International Nuclear Information System (INIS)

    Duval, M.; Falgueres, Ch.; Bahain, J.J.; Shao, Q.; Grun, R.; Aubert, M.; Hellstrom, J.; Dolo, J.M.; Agusti, J.; Martinez-Navarro, B.; Palmqvist, P.; Toro-Moyano, I.

    2011-01-01

    The palaeontological site of Venta Micena (Orce, Andalusia, Spain) lies in the eastern sector of the Guadix-Baza basin, one of the best documented areas in Europe for Plio-Pleistocene bio-stratigraphy. The combination of bio-chronological and palaeo-magnetic results, combined with the radiometric data obtained for Atapuerca Sima del Elefante, indicated that the Venta Micena stratum was formed between the Jaramillo and Olduvai palaeo-magnetic events, most likely between 1.22 and 1.77 Ma. Five fossil teeth from two outcrops (sites A and B) were selected to assess the potential of combined uranium series-electron spin resonance (US-ESR) dating of Early Pleistocene sites. Although the US-ESR results of the first outcrop showed a large scatter between the three teeth, the mean age of 1.37 ± 0.24 Ma can be considered a reasonable age estimate for Venta Micena. The mean ESR age of 0.62 ± 0.03 Ma obtained for site B seems to be a severe underestimation when compared with the independent age control. This underestimation is attributed to a relative recent U-mobilization event that led to some U-leaching. The results show that any ESR age calculations of old samples are extremely sensitive to variations in the measured 230 Th/ 234 U ratios in dental tissues. Although the results demonstrate that ESR can in principle be applied to Early Pleistocene sites, they also reveal the complexity of dating such old teeth. It is necessary to continue research in several directions, such as study of the behaviour of ESR signals in old teeth and understanding recent U-mobilization processes, to improve the reliability of the combined US-ESR dating method applied to Early Pleistocene times, a period for which the number of available numerical dating techniques is very limited. (authors)

  8. An Enduring Shell Artefact Tradition from Timor-Leste: Oliva Bead Production from the Pleistocene to Late Holocene at Jerimalai, Lene Hara, and Matja Kuru 1 and 2.

    Directory of Open Access Journals (Sweden)

    Michelle C Langley

    Full Text Available In this paper, we describe 485 Oliva spp. shell beads recovered from four archaeological cave sites Jerimalai, Lene Hara, Matja Kuru 1, and Matja Kuru 2, located in Timor-Leste, Island Southeast Asia. While Pleistocene-aged examples of modified marine shells used for personal ornamentation are common in African and Eurasian assemblages, they are exceedingly rare in Southeast Asia, leading some researchers to suggest that these Modern Human societies were less complex than those found further west. In Timor-Leste, the lowest Oliva bead to be recovered was directly dated to ca. 37,000 cal. BP, making it the oldest piece of personal ornamentation in Southeast Asia. Morphometric, taphonomic, use wear, and residue analyses of these beads alongside modern reference specimens, and experimentally made examples indicate that the Oliva shells were modified to be strung consecutively (as in a necklace, and while their mode of production changed remarkably little over the thousands of years they were utilised, an increase in their deposition around 6,000 cal. BP suggests that there was a change in their use coinciding with sea-level stabilisation. These tiny beads demonstrate that early Island Southeast Asian societies produced the same kinds of symbolic material culture we have come to expect from the more intensively studied African/Eurasian region, and that limited sampling and poor recovery methods have biased our perspectives of this region.

  9. The genetic structure of the mountain forest butterfly Erebia euryale unravels the late Pleistocene and postglacial history of the mountain coniferous forest biome in Europe.

    Science.gov (United States)

    Schmitt, Thomas; Haubrich, Karola

    2008-05-01

    The distribution of the mountain coniferous forest biome in Europe throughout time is not sufficiently understood. One character species of this habitat type is the large ringlet, Erebia euryale well reflecting the extension of this biome today, and the genetic differentiation of this species among and within mountain systems may unravel the late Pleistocene history of this habitat type. We therefore analysed the allozyme pattern of 381 E. euryale individuals from 11 populations in four different European mountain systems (Pyrenees, Alps, Carpathians, Rila). All loci analysed were polymorphic. The mean F(ST) over all samples was high (20%). Furthermore, the mean genetic distance among samples was quite high (0.049). We found four different groups well supported by cluster analyses, bootstraps and hierarchical variance analyses: Pyrenees, western Alps, eastern Alps and southeastern Europe (Carpathians and Rila). The genetic diversity of the populations was highest in the southeastern European group and stepwise decreased westwards. Interestingly, the populations from Bulgaria and Romania were almost identical; therefore, we assume that they were not separated by the Danube Valley, at least during the last ice age. On the contrary, the differentiation among the three western Alps populations was considerable. For all these reasons, we assume that (i) the most important refugial area for the coniferous mountain forest biome in Europe has been located in southeastern Europe including at least parts of the Carpathians and the Bulgarian mountains; (ii) important refugial areas for this biome existed at the southeastern edge of the Alps; (iii) fragments of this habitat types survived along the southwestern Alps, but in a more scattered distribution; and (iv) relatively small relicts have persisted somewhere at the foothills of the Pyrenees.

  10. Record of late Pleistocene glaciation and deglaciation in the southern Cascade Range. I. Petrological evidence from lacustrine sediment in Upper Klamath Lake, southern Oregon

    Science.gov (United States)

    Reynolds, R.L.; Rosenbaum, J.G.; Rapp, J.; Kerwin, M.W.; Bradbury, J.P.; Colman, S.; Adam, D.

    2004-01-01

    Petrological and textural properties of lacustrine sediments from Upper Klamath Lake, Oregon, reflect changing input volumes of glacial flour and thus reveal a detailed glacial history for the southern Cascade Range between about 37 and 15 ka. Magnetic properties vary as a result of mixing different amounts of the highly magnetic, glacially generated detritus with less magnetic, more weathered detritus derived from unglaciated parts of the large catchment. Evidence that the magnetic properties record glacial flour input is based mainly on the strong correlation between bulk sediment particle size and parameters that measure the magnetite content and magnetic mineral freshness. High magnetization corresponds to relatively fine particle size and lower magnetization to coarser particle size. This relation is not found in the Buck Lake core in a nearby, unglaciated catchment. Angular silt-sized volcanic rock fragments containing unaltered magnetite dominate the magnetic fraction in the late Pleistocene sediments but are absent in younger, low magnetization sediments. The finer grained, highly magnetic sediments contain high proportions of planktic diatoms indicative of cold, oligotrophic limnic conditions. Sediment with lower magnetite content contains populations of diatoms indicative of warmer, eutrophic limnic conditions. During the latter part of oxygen isotope stage 3 (about 37-25 ka), the magnetic properties record millennial-scale variations in glacial-flour content. The input of glacial flour was uniformly high during the Last Glacial Maximum, between about 21 and 16 ka. At about 16 ka, magnetite input, both absolute and relative to hematite, decreased abruptly, reflecting a rapid decline in glacially derived detritus. The decrease in magnetite transport into the lake preceded declines in pollen from both grass and sagebrush. A more gradual decrease in heavy mineral content over this interval records sediment starvation with the growth of marshes at the margins

  11. Vegetation dynamics during the late Pleistocene in the Barreirinhas region, Maranhão State, northeastern Brazil, based on carbon isotopes in soil organic matter

    Science.gov (United States)

    Pessenda, Luiz Carlos Ruiz; Ribeiro, Adauto de Souza; Gouveia, Susy Eli Marques; Aravena, Ramon; Boulet, Rene; Bendassolli, José Albertino

    2004-09-01

    The study place is in the Barreirinhas region, Maranhão State, northeastern Brazil. A vegetation transect of 78 km was studied among four vegetation types: Restinga (coastal vegetation), Cerrado (woody savanna), Cerradão (dense woody savanna), and Forest, as well as three forested sites around Lagoa do Caçó, located approximately 10 km of the transect. Soil profiles in this transect were sampled for δ13C analysis, as well as buried charcoal fragments were used for 14C dating. The data interpretation indicated that approximately between 15,000 and ˜9000 14C yr B.P., arboreal vegetation prevailed in the whole transect, probably due to the presence of a humid climate. Approximately between ˜9000 and 4000-3000 14C yr B.P., there was the expansion of the savanna, probably related to the presence of drier climate. From ˜4000-3000 14C yr B.P. to the present, the results indicated an increase in the arboreal density in the area, due to the return to a more humid and probably similar climate to the present. The presence of buried charcoal fragments in several soil depths suggested the occurrence of palaeofires during the Holocene. The vegetation dynamic inferred in this study for northeastern Brazil is in agreement with the results obtained in areas of Amazon region, based on pollen analysis of lake sediments and carbon isotope analysis of soil organic matter (SOM), implying than similar climatic conditions have affected these areas during the late Pleistocene until the present.

  12. Fault Slip Partitioning in the Eastern California Shear Zone-Walker Lane Belt: Pliocene to Late Pleistocene Contraction Across the Mina Deflection

    Science.gov (United States)

    Lee, J.; Stockli, D.; Gosse, J.

    2007-12-01

    Two different mechanisms have been proposed for fault slip transfer between the subparallel NW-striking dextral- slip faults that dominant the Eastern California Shear Zone (ECSZ)-Walker Lane Belt (WLB). In the northern WLB, domains of sinistral-slip along NE-striking faults and clockwise block rotation within a zone of distributed deformation accommodated NW-dextral shear. A somewhat modified version of this mechanism was also proposed for the Mina deflection, southern WLB, whereby NE-striking sinistral faults formed as conjugate faults to the primary zone of NW-dextral shear; clockwise rotation of the blocks bounding the sinistral faults accommodated dextral slip. In contrast, in the northern ECSZ and Mina deflection, domains of NE-striking pure dip-slip normal faults, bounded by NW-striking dextral-slip faults, exhibited no rotation; the proposed mechanism of slip transfer was one of right-stepping, high angle normal faults in which the magnitude of extension was proportional to the amount of strike-slip motion transferred. New geologic mapping, tectonic geomorphologic, and geochronologic data from the Queen Valley area, southern Mina deflection constrain Pliocene to late Quaternary fault geometries, slip orientations, slip magnitudes, and slip rates that bear on the mechanism of fault slip transfer from the relatively narrow northern ECSZ to the broad deformation zone that defines the Mina deflection. Four different fault types and orientations cut across the Queen Valley area: (1) The NE-striking normal-slip Queen Valley fault; (2) NE-striking sinistral faults; (3) the NW-striking dextral Coyote Springs fault, which merges into (4) a set of EW-striking thrust faults. (U-Th)/He apatite and cosmogenic radionuclide data, combined with magnitude of fault offset measurements, indicate a Pliocene to late Pleistocene horizontal extension rate of 0.2-0.3 mm/yr across the Queen Valley fault. Our results, combined with published slip rates for the dextral White Mountain

  13. Personality differences in early versus late suicide attempters.

    Science.gov (United States)

    Lewitzka, Ute; Denzin, Sebastian; Sauer, Cathrin; Bauer, Michael; Jabs, Burkhard

    2016-08-09

    Suicidality is an individual behaviour caused by a complex framework of internal and external factors. The predictive values of personality traits for a suicide attempt have been demonstrated, especially in conjunction with Cloninger's TCI and impulsivity. Two issues remain unsolved, namely whether these traits alter over time after a suicide attempt, and how they may be influenced by depressive symptoms. We studied two patient cohorts: one sample of 81 patients after a suicide attempt no longer than 3 months previously (SA early) and another sample of 32 patients whose attempt had taken place more than 6 months previously (SA late). We carried out structured interviews with these subjects addressing diagnosis (MINI), suicidality (Scale for suicide ideation), depression (HAMD-17), temperament and character inventory (TCI), and impulsivity (BIS-10). Data analysis was done using SPSS 16.0. Our two groups did not differ significantly in sociodemographics or suicidality. However, patients in the SA early group were significantly more depressed (p impulsivity (p suicide attempt. Further investigations are necessary to verify our results, ideally in longitudinal studies with larger, carefully-described cohorts. It would be also clinically important to investigate the influence of therapeutic strategies on the variability of personality traits and their impact on suicidal behavior.

  14. Shedding light on the Early Pleistocene of TD6 (Gran Dolina, Atapuerca, Spain): The technological sequence and occupational inferences.

    Science.gov (United States)

    Mosquera, Marina; Ollé, Andreu; Rodríguez-Álvarez, Xose Pedro; Carbonell, Eudald

    2018-01-01

    This paper aims to update the information available on the lithic assemblage from the entire sequence of TD6 now that the most recent excavations have been completed, and to explore possible changes in both occupational patterns and technological strategies evidenced in the unit. This is the first study to analyse the entire TD6 sequence, including subunits TD6.3 and TD6.1, which have never been studied, along with the better-known TD6.2 Homo antecessor-bearing subunit. We also present an analysis of several lithic refits found in TD6, as well as certain technical features that may help characterise the hominin occupations. The archaeo-palaeontological record from TD6 consists of 9,452 faunal remains, 443 coprolites, 1,046 lithic pieces, 170 hominin remains and 91 Celtis seeds. The characteristics of this record seem to indicate two main stages of occupation. In the oldest subunit, TD6.3, the lithic assemblage points to the light and limited hominin occupation of the cave, which does, however, grow over the course of the level. In contrast, the lithic assemblages from TD6.2 and TD6.1 are rich and varied, which may reflect Gran Dolina cave's establishment as a landmark in the region. Despite the occupational differences between the lowermost subunit and the rest of the deposit, technologically the TD6 lithic assemblage is extremely homogeneous throughout. In addition, the composition and spatial distribution of the 12 groups of lithic refits found in unit TD6, as well as the in situ nature of the assemblage demonstrate the high degree of preservation at the site. This may help clarify the nature of the Early Pleistocene hominin occupations of TD6, and raise reasonable doubt about the latest interpretations that support the ex situ character of the assemblage as a whole.

  15. Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications

    Science.gov (United States)

    Qiang, Xiaoke; Xu, Xinwen; Zhao, Hui; Fu, Chaofeng

    2018-05-01

    The ferrimagnetic iron sulfide greigite (Fe3S4) occurs widely in sulfidic lacustrine and marine sedimentary environments. Knowledge of its formation and persistence is important for both magnetostratigraphic and paleoenvironmental studies. Although the formation mechanism of greigite has been widely demonstrated, the sedimentary environments associated with greigite formation in lakes, especially on relatively long timescales, are poorly understood. A long and continuous sequence of Pleistocene lacustrine sediments was recovered in the Heqing drill core from southwestern China, which provides an outstanding record of continental climate and environment. Integrated magnetic, geochemical, and paleoclimatic analysis of the lacustrine sequence provides an opportunity to improve our understanding of the environmental controls on greigite formation. Rock magnetic and scanning electron microscope analyses of selected samples from the core reveal that greigite is present in the lower part of the core (part 1, 665.8-372.5 m). Greigite occurs throughout this interval and is the dominant magnetic mineral, irrespective of the climatic state. The magnetic susceptibility (χ) record, which is mainly controlled by the concentration of greigite, matches well with variations in the Indian Summer Monsoon (ISM) index and total organic carbon (TOC) content, with no significant time lag. This indicates that the greigite formed during early diagenesis. In greigite-bearing intervals, with the χ increase, Bc value increase and tends to be stable at about 50 mT. Therefore, we suggest that χ values could estimate the variation of greigite concentration approximately in the Heqing core. Greigite favored more abundant in terrigenous-rich and organic-poor layers associated with weak summer monsoon which are characterized by high χ values, high Fe content, high Rb/Sr ratio and low TOC content. Greigite enhancement can be explained by variations in terrigenous inputs. Our studies demonstrate

  16. Late Tharsis tectonic activity and implications for Early Mars

    Science.gov (United States)

    Bouley, S.; Baratoux, D.; Paulien, N.; Missenard, Y.; Saint-Bezar, B.

    2017-12-01

    Constraining the timing of Tharsis volcanism is critical to understanding the planet's evolution including its climate, surface environment and mantle dynamics. The tectonic history of the Tharsis bulge was previously documented from the distribution and ages of related tectonic features [1]. Here we revisit the ages of 7493 Tharsis-related tectonic features based on their relationship with stratigraphic units defined in the new geological map [2]. Conversely to previous tectonic mapping [1], which suggested that Tharsis growth was nearly achieved during the Noachian, we find a protracted growth of Tharsis during the Hesperian. Faulting at Tempe Terra, Claritas and Coracis Fossae and Thaumasia Planum confirms that tectonic deformation started during the Noachian. Accumulated tectonic deformation was maximum in the Early Hesperian for compressional strain (Solis, Lunae and Ascuris Planum) and extended over time from Noachian to Amazonian for extensional strain (Noctis Labyrinthus and Fossae, Sinai Planum and Tractus, Ulysses and Fortuna fossae, Alba Patera). This new scenario is consistent with a protracted growth of Tharsis dome during the Hesperian and with the timing a large Tharsis-driven true polar wander post-dating the incision of Late Noachian/Hesperian valley networks[3]. References:[1] Anderson et al. JGR-Planets 106, E9, 20,563-20,585 (2001).[2] Tanaka, K.L. et al. Geologic map of Mars (2014). [3] Bouley et al. Nature doi:10.1038 (2016)

  17. Parkinson's disease therapy: treatment of early and late disease

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Purpose To summarize the current strategies for the treatment of early and late Parkinson's disease (PD). Data sources The presented guidelines are based on the review of the literature as well as the author's extensive experience with the treatment of 7000 patients with PD over the past 25 years. Results An analysis of reported data as well as personal experience suggest that while young patients seem to have a slower progression of the disease, they are at a higher risk for developing levodopa induced complications, such as motor fluctuations and dyskinesias. It is, therefore, prudent practice to delay levodopa therapy, particularly in younger patients, until the PD symptoms become troublesome and interfere with social or occupational functioning. Other strategies, such as the use of deprenyl, amantadine, trihexyphenidyl and dopamine agonists, should be employed before instituting levodopa therapy. Entacopone and dopamine agonists are useful in smoothing out levodopa related motor fluctuations. Surgical interventions, such as pallidotomy and pallidal or subthalamic deep brain stimulation, are effective therapeutic strategies, but should be reserved only for patients in whom optimal medical therapy fails to provide satisfactory control of symptoms. Conclusion The medical and surgical treatment of patients with PD must be individualized and tailored to the needs of the individual patient.

  18. Late Carboniferous and Early Permian algal microflora (Liuzhou, South China)

    Energy Technology Data Exchange (ETDEWEB)

    Li Chun (Nanjing Inst. of Geology and Paleontology, Nanjing (China)); Mamet, B. (Montreal Univ., PQ (Canada))

    1993-03-01

    Paleozoic algae are important contributors to the formation of carbonate sediments. A study was conducted to compare an Upper Carboniferous-Lower Permian carbonate succession of South China with what is generally observed in the Tethys Sea and North America. The sequence studied was in the Maping Limestone at the Loutishan section in Liuzhou, with some additional information derived from the Maping Limestone at Shangxinping and from the Chuanshan Limestone at Yuhuangshan and in the Nanjing Hills. In the Late Carboniferous, the beresellid algae are important builders and the Tubiphytes-Archaeolithophyllum community is locally replaced by a Tubiphytes-Ungdarella association. Early Permian oncolites were formed by complex Osagia, then by Esmerella. The Asselian Sphaeroschwagerina fauna is underlined by the outburst of epimastoporid dasycladales and phylloid Anchicodiaceae. Microcodium is observed at the contact of the Sphaeroschwagerina moelleri/sphaerica Zones. The overlying and paraconformable Chihsia Limestone is characterized by a Gymnocodium-Gyroporella-Mizzia flora. In most cases, the base of the fusulinid zones, therefore, coincides with an important local floristic change. 72 refs., 4 figs.

  19. Early and Late Onset Side Effects of Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Francesco Borgia

    2018-01-01

    Full Text Available Photodynamic Therapy (PDT is a non-invasive treatment successfully used for neoplastic, inflammatory and infectious skin diseases. One of its strengths is represented by the high safety profile, even in elderly and/or immuno-depressed subjects. PDT, however, may induce early and late onset side effects. Erythema, pain, burns, edema, itching, desquamation, and pustular formation, often in association with each other, are frequently observed in course of exposure to the light source and in the hours/days immediately after the therapy. In particular, pain is a clinically relevant short-term complication that also reduces long-term patient satisfaction. Rare complications are urticaria, contact dermatitis at the site of application of the photosensitizer, and erosive pustular dermatosis. Debated is the relationship between PDT and carcinogenesis: the eruptive appearance of squamous cell carcinoma (SCC in previously treated areas has been correlated to a condition of local and/or systemic immunosuppression or to the selection of PDT-resistant SCC. Here we review the literature, with particular emphasis to the pathogenic hypotheses underlying these observations.

  20. The association between mid-facial morphology and climate in northeast Europe differs from that in north Asia: Implications for understanding the morphology of Late Pleistocene Homo sapiens.

    Science.gov (United States)

    Evteev, Andrej A; Movsesian, Alla A; Grosheva, Alexandra N

    2017-06-01

    The climate of northeastern Europe is likely to resemble in many ways Late Pleistocene periglacial conditions in Europe, but there have been relatively few studies exploring the association between climate and morphology in the mid-face of modern northeastern European populations. To fill this gap, we sampled 540 male skulls from 22 European and Near Eastern groups, including 314 skulls from 11 populations from northeastern Europe, to test for possible climate-morphology association at the continental scale. Our results found a moderate and highly significant association (R = 0.48, p = 0.0013, Mantel test) between sets of 23 mid-facial measurements and eight climatic variables. A partial least squares analysis revealed this association to be mostly driven by differences between groups from northeastern Europe and populations from the Mediterranean and the Caucasus. Matrices of between-group genetic distances based on Y-chromosome and mtDNA markers, as well as cranial non-metric and geographic distance matrices, were used to control for the possible influence of shared population history. Irrespective of which measure of neutral between-population distances is taken into account, the association between cranial variables and climate remains significant. The pattern of association between climate and morphology of the mid-face in western Eurasia was then compared to that in east and north Asia. Although differences between the two were found, there were also similarities that support existing functional interpretations of morphology for the bony parts of the upper airways. Last, in a preliminary analysis using a reduced set of measurements, mid-facial morphology of several Upper Paleolithic European Homo sapiens specimens was found to be more similar to groups from northern and northeastern Europe than to southern European populations. Thus, the population of northeastern Europe rather than east and north Asian groups should be used as a model when studying

  1. Rapid anthropogenic response to short-term aeolian-fluvial palaeoenvironmental changes during the Late Pleistocene-Holocene transition in the northern Negev Desert, Israel

    Science.gov (United States)

    Roskin, Joel; Katra, Itzhak; Agha, Nuha; Goring-Morris, A. Nigel; Porat, Naomi; Barzilai, Omry

    2014-09-01

    transient ‘window' of improved local aeolian-fluvial palaeoenvironmental conditions during the Late Pleistocene-Holocene transition, but don't necessarily point to a wetter or drier palaeoclimate.

  2. Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

    Energy Technology Data Exchange (ETDEWEB)

    Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2016-01-01

    Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed the dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late

  3. Discussion of "Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California" (Schumann et al., 2016. Geomorphology, 268: 322-340)

    Science.gov (United States)

    Pinter, Nicholas; Hardiman, Mark; Scott, Andrew C.; Anderson, R. Scott

    2018-01-01

    Schumann et al. (2016) presented a field assessment of late Pleistocene to Holocene fluvial sediments preserved in the valleys of Santa Rosa Island, California. This is a rigorous study, based on stratigraphic descriptions of 54 sections and numerous radiocarbon ages. The paper makes important contributions that we would like to highlight, but other parts of the paper rely upon overly simplistic interpretations that lead to misleading conclusions. In one case, a conclusion of the Schumann et al. paper has important management implications for Santa Rosa Island and similar locations, compelling us to discuss and qualify this conclusion.

  4. Recycling of Badger/Fox Burrows in Late Pleistocene Loess by Hyenas at the Den Site Bad Wildungen-Biedensteg (NW, Germany): Woolly Rhinoceros Killers and Scavengers in a Mammoth Steppe Environment of Europe

    OpenAIRE

    Diedrich, Cajus

    2013-01-01

    The Late Pleistocene (MIS 5c-d) Ice Age spotted hyena open air den and bone accumulation site Bad Wildungen-Biedensteg (Hesse, NW, Germany) represents the first open air loess fox/badger den site in Europe, which must have been recycled by Crocuta crocuta spelaea (Goldfuss, 1823) as a birthing den. Badger and fox remains, plus remains of their prey (mainly hare), have been found within the loess. Hyena remains from that site include parts of cub skeletons which represent 10% of the megafauna ...

  5. The Alleret Maar lacustrine sequence (French Massif Central): a 150 ka long early-middle Pleistocene continental paleoenvironmental record.

    Science.gov (United States)

    Nomade, S.; Pastre, J.; Guillou, H.; Gauthier, A.; Scaillet, S.

    2008-12-01

    Lacustrine maar sequences of the French Massif Central are of great interest for paleoclimatic and paleoenvironmental reconstructions of mid-latitudes Quaternary continental environments. In particular, the western Velay region yields exceptional sequences spanning the last 450 ka (Reille et al., J. Quat. Sci. 2000). However, older sequences remain largely unknown despite the presence of interbedded alkaline tephras allowing precise absolute radiochronological control of many lacustrine squences. The Alleret maar is a 1500 m wide phreatomagmatic crater that provides a long lacustrine sequence (41 m). The upper part of this sequence (AL2 core, 14.6 m) was studied between 2005 and 2006 (Pastre et al., C. R. Acad Sci, 2007). A 39Ar/40Ar date (557 ± 5ka) obtained from an interbedded tephra layer located at 7m as well as the associated pollen data attribute the beginning of this sequence to the MIS 15. Thanks to the AL3 core recovered in 2005 (40.6 m, CNRS Meudon) several new tephra layers were discovered in the bottom part of this lacustrine sequence. Three new 39Ar/40Ar ages (single crystal analyses) from trachytic tephra layers were obtained at the LSCE Argon Laboratory (France). These layers are located at -30.2, -36.2 and -39.2m. Ages obtained relative to the ACR-2 flux standard (1,201Ma, Kuiper et al., Science, 2008) range from 692 ± 6 ka (MSWD: 2.3, n=18) for the youngest (-30.2m) to 726 ± 9Ka Ka (MSWD: 2.2, n=12) for the lowest tephra located at -39.2m. These new dates indicate a relatively homogeneous deposition rate of 3.5cm/ka and that the last 10 meters cover the MIS 17-MIS18 period. According to these current radiochronological data the complete lacustrine sequence last more than 150ka. Ongoing sedimentary and pollen studies will allow to extend the paleoenvironmental and paleoclimatic records of the French Massif Central towards the beginning of the early middle Pleistocene.

  6. The Protocol for the Early vs. Late Infantile Strabismus Surgery Study

    NARCIS (Netherlands)

    H.J. Simonsz (Huib)

    1993-01-01

    textabstractAbstract. The Early vs. Late Infantile Strabismus SurgerY Study Group is a group of strabismologists and orthoptists who investigate whether early or late surgery is preferable in infantile strabismus, in a non-randomized, prospective, multi-centre trial. Infants between 6 and 18 months

  7. The paleoclimate of the Kazanian (early Late Permian) world

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G.T. (Chevron Oil Field Research Co., La Habra, CA (USA)); Peoples, C.J. (Texas A and M Univ., College Station (USA))

    1990-05-01

    The Kazanian (early Late Permian, 258-253 m.y.) marked the onset of a unique interval in the Phanerozoic, distinguished by a classic end-member case of continental assembly, the megacontinent Pangaea. Compilation of biostratigraphic and lithofacies data indicate a warm, extensively arid world, largely ice free, and characterized by the onset of atmospheric conditions that were exceedingly stressful to the biosphere, the worst of the eon. Using Chevron's version of the Community Climate model, the authors report here on two Kazanian paleoclimate seasonal simulations, one using 200 ppm CO{sub 2} and the other with 2,000 ppm CO{sub 2}. The authors consider the knowledge of plate assembly back to the Permian accurate enough to allow employment of a seasonal model. Simulation of a warmer Earth with an elevated greenhouse effect (modeled as CO{sub 2}) fits the observed geology and isotope signals. The increased CO{sub 2} experiment warmed the entire planet with the greatest increases north of 50{degree} latitude and least changes in the tropics. The warming caused the poleward retreat of sea ice in both hemispheres. Precipitation and evaporation increased, but runoff was confined to areas of very intense rainfall. Monsoons are limited to the southern hemisphere, associated with the western Tethys sea and the eastern equatorial Panthalassa ocean. Extreme southeastern Pangaea (northern Australia) was a focus of precipitation throughout the year. Precipitation occurred in the higher latitudes (50-55{degree}) on the western coast, of Pangaea where storm tracks make landfall. High evaporation rates characterized the restricted Permian (US), Zechstein, and Perm (Soviet Union) basins, a time of evaporite, deposition. Interior Pangaea at middle to high latitudes endured frigid winters ({minus}40{degree}C) and torrid summers (60{degree}C).

  8. The presence of Ursus ex gr. minimus-thibetanus in the late villányian and its position among the Pliocene and Pleistocene black bears in Europe

    Czech Academy of Sciences Publication Activity Database

    Wagner, Jan; Čermák, Stanislav; Horáček, I.

    -, č. 4 (2011), s. 39-58 ISSN 1771-1150 R&D Projects: GA ČR GA205/09/0184 Institutional research plan: CEZ:AV0Z30130516 Keywords : Black bear * MN17 * Ursus aff. thibetanus * Villány 3 * Central Europe - Hungary * Ursus * Pleistocene * Pliocene Subject RIV: DB - Geology ; Mineralogy

  9. Geochemical characterization of the middle and late Pleistocene alluvial fan-dominated infill of the northern part of the Weihe Basin, Central China

    NARCIS (Netherlands)

    Rits, Daniël S.; Beets, Christiaan J.; Prins, Maarten A.; van Balen, Ronald T.; Troelstra, Simon R.; Luo, Chao; Wang, B.; Li, Xiaoqiang; Zhou, Jie; Zheng, Hongbo

    2017-01-01

    Major reorganizations in climate and tectonic regime occurred in East Asia during the Pleistocene, resulting in large-scale environmental changes. In this paper a detailed geochemical and mineralogical record of these changes is presented from a distal alluvial fan sedimentary sequence in the

  10. Optimisation of irrigation regime for early potatoes, late cauliflower, early cabbage and celery

    International Nuclear Information System (INIS)

    Zavadil, J.

    2006-01-01

    The paper deals with optimisation of threshold suction pressure of soil water on light soils for early potatoes, early cabbage, late cauliflower and celery on the basis of results from small-plot field experiments with differentiated irrigation regimes. Threshold suction pressures of soil water were identical for all crops: 15 kPa in treatment I, 30 kPa in treatment II, 60 kPa in treatment III, and 120 kPa in treatment IV. Precipitation, air temperature and relative humidity, global solar radiation, wind speed and direction were measured by an automated meteorological station. Reference and actual evapotranspirations were determined for the experimental crops according to FAO Paper No. 56 and by means of a biological curve (BC) in 2003-2005. To compare these two methods of calculation of actual evapotranspiration the soil moisture balance was found out. The optimum threshold suction pressure was 30 kPa for early potatoes, late cauliflower and cabbage and 15 kPa for celery. The seasonal irrigation depths determined on the basis of soil moisture balance, in which the crop evapotranspiration (ETc) was calculated either according to FAO 56 or by the BC, were substantially different from the really achieved irrigation depths with optimal suction pressure. The really achieved values were near to the depths calculated by the BC for potatoes, while for cauliflower, cabbage and celery they were similar to the depths calculated by the FAO 56 methodology. The theoretical irrigation depths calculated by the BC method sometimes differed substantially from those based on FAO 56. These differences were maximal for cauliflower and celery and minimal for cabbage. They decreased with decreasing irrigation depths. (author)

  11. Childhood abuse and late-life depression: Mediating effects of psychosocial factors for early- and late-onset depression.

    Science.gov (United States)

    Wielaard, Ilse; Hoyer, Mathijs; Rhebergen, Didi; Stek, Max L; Comijs, Hannie C

    2018-03-01

    Childhood abuse makes people vulnerable to developing depression, even in late life. Psychosocial factors that are common in late life, such as loneliness or lack of a partner, may explain this association. Our aim was to investigate whether the association between childhood abuse and depression in older adults can be explained by psychosocial factors. Cross-sectional data were derived from the Netherlands Study of Depression in Older Persons (aged 60-93), including 132 without lifetime depression, 242 persons with an early-onset depression (Childhood abuse (yes/no) and a frequency-based childhood abuse index were included. Multinomial regression and multivariable mediation analyses were used to examine the association between childhood abuse and the onset of depression, and the influence of loneliness, social network, and partner status. Multinomial regression analyses showed a significant association between childhood abuse and the childhood abuse index with early- and late-onset depression. Multivariable mediation analyses showed that the association between childhood abuse and early-onset depression was partly mediated by social network size and loneliness. This was particularly present for emotional neglect and psychological abuse, but not for physical and sexual abuse. No psychosocial mediators were found for the association between childhood abuse and late-onset depression. A smaller social network and feelings of loneliness mediate the association between childhood abuse and early-onset depression in older adults. Our findings show the importance of detecting childhood abuse as well as the age at depression onset and mapping of relevant psychosocial factors in the treatment of late-life depression. Copyright © 2018 John Wiley & Sons, Ltd.

  12. PLIO-PLEISTOCENE FOSSIL VERTEBRATES OF MONTE TUTTAVISTA (OROSEI, EASTERN SARDINIA, ITALY, AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    LAURA ABBAZZI

    2004-11-01

    Full Text Available The preliminary results of the analisys of fossil vertebrate remains from 19 fissure fillings in the karst network at Monte Tuttavista (Orosei, NMoro are reported. about 80 taxa, among fishes, amphibians, reptiles, birds and mammals have been recognised.These remains document the evolution of vertebrate assemblages in the Sardinian insular domain, during a time interval apparently spanning the Late Pliocene to Late Pleistocene or Holocene. A succession of at least four populating complexes has been identified which document the vertebrate colonisation phases from the Italian mainland and the following periods of insularity. Indeed, the occurrence of endemic taxa such as the murid Rhagapodemus minor, the primate Macaca cf. M. majori and the caprine Nesogoral, suggest some fissure fillings date to a phase close to the Plio/Pleistocene boundary since these taxa occur at the Sardinian locality Capo Figari I which has been dated to about 1.8 Ma. However, the presence of the "hunting-hyaena" Chasmaporthetes, never reported before in Sardinia, could suggest that the beginning of the vertebrate record of Monte Tuttavista is older, given that this carnivore is documented in European Middle Pliocene-Early Pleistocene localities. The vertebrate assemblages that document the most recent migratory phases in the karst network of Monte Tuttavista are characterised by the occurrence of the endemic megalocerine cervid Praemegaceros cazioti and the arvicolid Tyrrhenicola henseli which are comparable with those occurring in other Late Pleistocene and early Holocene Sardinian sites.

  13. Factor analysis of symptom profile in early onset and late onset OCD.

    Science.gov (United States)

    Grover, Sandeep; Sarkar, Siddharth; Gupta, Gourav; Kate, Natasha; Ghosh, Abhishek; Chakrabarti, Subho; Avasthi, Ajit

    2018-04-01

    This study aimed to assess the factor structure of early and late onset OCD. Additionally, cluster analysis was conducted in the same sample to assess the applicability of the factors. 345 participants were assessed with Yale Brown Obsessive Compulsive Scale symptom checklist. Patients were classified as early onset (onset of symptoms at age ≤ 18 years) and late onset (onset at age > 18 years) OCD depending upon the age of onset of the symptoms. Factor analysis and cluster analysis of early-onset and late-onset OCD was conducted. The study sample comprised of 91 early onset and 245 late onset OCD subjects. Males were more common in the early onset group. Differences in the frequency of phenomenology related to contamination related, checking, repeating, counting and ordering/arranging compulsions were present across the early and late onset groups. Factor analysis of YBOCS revealed a 3 factor solution for both the groups, which largely concurred with each other. These factors were named as hoarding and symmetry (factor-1), contamination (factor-2) and aggressive, sexual and religious factor (factor-3). To conclude this study shows that factor structure of symptoms of OCD seems to be similar between early-onset and late-onset OCD. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Soluble human leukocyte antigen-G isoforms in maternal plasma in early and late pregnancy

    DEFF Research Database (Denmark)

    Rizzo, Roberta; Andersen, Anita Sylvest; Lassen, Michael Rud

    2009-01-01

    -G generated by specific HLA-G transcripts, have been investigated early [median of 16.4 weeks of gestation (GW)] and late (median: 38.9 GW) in pregnancy in an original cohort of 580 pregnant Caucasian women. RESULTS: Lower concentrations of sHLA-G1 were found late in pregnancy (>32 GW) in a group of women...

  15. Maternal serum copeptin concentrations in early- and late-onset pre-eclampsia

    Directory of Open Access Journals (Sweden)

    Abdullah Tuten

    2015-08-01

    Conclusion: Our results suggest that copeptin levels might be useful in the evaluation of the severity of pre-eclampsia. However, copeptin might be involved in early- rather than late-onset pre-eclampsia.

  16. Nonvascular contribution to ecosystem NPP in a subarctic heath during early and late growing season

    DEFF Research Database (Denmark)

    Campioli, Matteo; Samson, Roeland; Michelsen, Anders

    2009-01-01

    significant when vascular plants are less active and ecosystems act as a source of carbon (C). To clarify these dynamics, nonvascular and vascular aboveground NPP was compared for a subarctic heath during two contrasting periods of the growing season, viz. early-mid summer and late summer-early autumn...... measurements of shoot length increase. Vascular NPP was determined by harvesting shrub and herb apical growth and considering production due to stem secondary growth of shrubs. Hylocomium splendens and Pleurozium schreberi showed highest biomass growth in late summer, whereas for D. elongatum this occurred...... weight m-2 d-1, in early and late summer, respectively, whereas in the same periods vascular NPP was 3.6 and 1.1 g dry weight m-2 d-1. The contribution of nonvascular NPP to total aboveground NPP was therefore minor in early summer but substantial in late summer, when 25% of the C accumulated...

  17. Early versus late surgical drainage for obstructive pancreatitis in an experimental model

    NARCIS (Netherlands)

    Lamme, B.; Boermeester, M. A.; Straatsburg, I. H.; van Buijtenen, J. M.; Boerma, D.; Offerhaus, G. J. A.; Gouma, D. J.; van Gulik, T. M.

    2007-01-01

    BACKGROUND: Chronic pancreatitis (CP) is characterized by intractable abdominal pain, and pancreatic exocrine and endocrine dysfunction. This study investigated whether early surgical drainage of pancreatic duct obstruction leads to improved recovery of pancreatic function compared with late

  18. Cognitive Advantages and Disadvantages in Early and Late Bilinguals

    Science.gov (United States)

    Pelham, Sabra D.; Abrams, Lise

    2014-01-01

    Previous research has documented advantages and disadvantages of early bilinguals, defined as learning a 2nd language by school age and using both languages since that time. Relative to monolinguals, early bilinguals manifest deficits in lexical access but benefits in executive function. We investigated whether becoming bilingual "after"…

  19. The southernmost record of a large erethizontid rodent (Hystricomorpha: Erethizontoidea) in the Pleistocene of South America: Biogeographic and paleoenvironmental implications

    Science.gov (United States)

    Vezzosi, Raúl I.; Kerber, Leonardo

    2018-03-01

    The South American porcupines (Erethizontidae) are included in two genera: Chaetomys and Coendou. The latter is a very speciose taxon, with about 13 living species. During at least the late Pliocene-early Pleistocene, erethizontids immigrated to Central and North America during the Great American Biotic Interchange. Although some Pleistocene fossils have been reported, the Quaternary history of this clade is still understudied. The only known extinct species is Coendou magnus. In this work, a fossil of a porcupine is reported from an Upper Pleistocene fluvial sedimentary sequence cropping out in the Northern Pampa geomorphological region, Santa Fe Province, Argentina. Despite this group having different living forms widely distributed in South American Neotropical woodland habitats, the Pleistocene occurrences of Erethizontidae are scarce and limited to Upper Pleistocene deposits from Bolivia, Brazil, and Uruguay. Currently, the specimen here reported represents the only Pleistocene porcupine from Argentina with a stratigraphical context. The morphological characters as well as the dimensions indicate that it is close to the Pleistocene erethizontid Coendou magnus. In this context, the presence of this erethizontid in such a southern locality, together with other taxa recorded from this site and the associated geological and paleoenvironmental evidence, indicates subtropical conditions, compared with the current conditions, which may have allowed a southern displacement of taxa more related to woodlands and xeric subtropical environments.

  20. Patterns of depression, anxiety symptoms and coping styles among early and late adolescent students

    International Nuclear Information System (INIS)

    Yaqoob, N.; Khan, M.A.

    2014-01-01

    To compare the depression, anxiety symptoms and coping styles among early and late adolescent students. Study Design: Cross-sectional. Place and Duration of study: Study was carried out at University of the Punjab, Lahore from 17 February to 31st August 2010. Methods: A purposive sample of 600 students (boys=300; girls=300) was divided into two age groups; early adolescents (13-15 years) and late adolescents (16-18 years). Participants were administered beck anxiety inventory, beck depression inventory-II and coping strategies questionnaire. Data was analyzed on SPSS14 version using independent sample t test. Results: The overall results of the study indicated that early adolescents exhibit more depression and anxiety symptoms as compared to the late adolescents. Moreover, early and late adolescents each attempt to cope with stressors in a variety of ways as active practical coping styles were more utilized by late adolescents. On the other hand, religious focused and avoidance focused coping styles were mostly used by the early adolescents. Besides, there was no significant group difference on active distractive coping styles. Conclusion: The current study revealed that significant changes during adolescence may affect adaptive processes and have implications for intervention efforts aimed to reduce the negative effects of stress during this period. The findings also suggest early and late adolescents each attempt to cope with stressors in a variety of ways that become more diverse and adaptive with development through the adolescent years. (author)

  1. Size and shape stasis in late Pleistocene mammals and birds from Rancho La Brea during the Last Glacial-Interglacial cycle

    Science.gov (United States)

    Prothero, Donald R.; Syverson, Valerie J.; Raymond, Kristina R.; Madan, Meena; Molina, Sarah; Fragomeni, Ashley; DeSantis, Sylvana; Sutyagina, Anastasiya; Gage, Gina L.

    2012-11-01

    Conventional neo-Darwinian theory views organisms as infinitely sensitive and responsive to their environments, and considers them able to readily change size or shape when they adapt to selective pressures. Yet since 1863 it has been well known that Pleistocene animals and plants do not show much morphological change or speciation in response to the glacial-interglacial climate cycles. We tested this hypothesis with all of the common birds (condors, golden and bald eagles, turkeys, caracaras) and mammals (dire wolves, saber-toothed cats, giant lions, horses, camels, bison, and ground sloths) from Rancho La Brea tar pits in Los Angeles, California, which preserves large samples of many bones from many well-dated pits spanning the 35,000 years of the Last Glacial-Interglacial cycle. Pollen evidence showed the climate changed from chaparral/oaks 35,000 years ago to snowy piñon-juniper forests at the peak glacial 20,000 years ago, then back to the modern chaparral since the glacial-interglacial transition. Based on Bergmann's rule, we would expect peak glacial specimens to have larger body sizes, and based on Allen's rule, peak glacial samples should have shorter and more robust limbs. Yet statistical analysis (ANOVA for parametric samples; Kruskal-Wallis test for non-parametric samples) showed that none of the Pleistocene pit samples is statistically distinct from the rest, indicating complete stasis from 35 ka to 9 ka. The sole exception was the Pit 13 sample of dire wolves (16 ka), which was significantly smaller than the rest, but this did not occur in response to climate change. We also performed a time series analysis of the pit samples. None showed directional change; all were either static or showed a random walk. Thus, the data show that birds and mammals at Rancho La Brea show complete stasis and were unresponsive to the major climate change that occurred at 20 ka, consistent with other studies of Pleistocene animals and plants. Most explanations for such

  2. Late Pleistocene steppe lion Panthera leo spelaea (Goldfuss, 1810) footprints and bone records from open air sites in northern Germany - Evidence of hyena-lion antagonism and scavenging in Europe

    Science.gov (United States)

    Diedrich, Cajus G.

    2011-07-01

    Bone remains and a trackway of Pantheraichnus bottropensis nov. ichg. ichnsp. of the Late Pleistocene lion Panthera leo spelaea ( Goldfuss, 1810) have been recovered from Bottrop and other open air sites in northern Germany. Some of these bones are from open air hyena den sites. A relative high proportion of lion bones (20%) exhibit bite, chew or nibble marks, or bone crushing and nibbling caused by a large carnivore. Repeated patterns of similar bone damage have been compared to bone remains found at hyena dens in gypsum karst areas and cave sites in northern Germany. Ice Age spotted hyenas have been the main antagonists and the main scavengers on lion carcasses. The remains appear to have been imported often by hyenas into their communal dens, supporting the theory of strong hyena-lion antagonism, similar to the well documented antagonism between modern African lions and spotted hyenas. Most of the lion bones from the open air hyena den at Bottrop are probably a result of such antagonism, as are the rare remains of these carnivores found within large hyena prey bone accumulations along the Pleistocene rivers. The Emscher River terrace also has the largest quantity of hyena remains from open air river terrace sites in northern Germany. Their cub remains, and incomplete chewed prey bones from mammoths and woolly rhinoceroses, typical of hyena activity, underline the character of these sites as cub-raising and communal dens, where their prey was accumulated along the riverbanks in a similar manner to modern African hyenas.

  3. Evidence of Late Palaeocene-Early Eocene equatorial rain forest ...

    Indian Academy of Sciences (India)

    Prakash

    2009-11-02

    Nov 2, 2009 ... influx of CO2 during early Cenozoic times (Kent and Muttoni. 2008), besides ... Palaeocene – Eocene lignite and coal deposits of India. .... journey of the Indian subcontinent and massive outpouring ..... ice age (Plana 2004).

  4. Early and late endocrine effects in pediatric central nervous system diseases.

    Science.gov (United States)

    Aslan, Ivy R; Cheung, Clement C

    2014-01-01

    Endocrinopathies are frequently linked to central nervous system disease, both as early effects prior to the disease diagnosis and/or late effects after the disease has been treated. In particular, tumors and infiltrative diseases of the brain and pituitary, such as craniopharyngioma, optic pathway and hypothalamic gliomas, intracranial germ cell tumor, and Langerhans cell histiocytosis, can present with abnormal endocrine manifestations that precede the development of neurological symptoms. Early endocrine effects include diabetes insipidus, growth failure, obesity, and precocious or delayed puberty. With improving prognosis and treatment of childhood brain tumors, many survivors experience late endocrine effects related to medical and surgical interventions. Chemotherapeutic agents and radiation therapy can affect the hypothalamic-pituitary axes governing growth, thyroid, gonadal, and adrenal function. In addition, obesity and metabolic alterations are frequent late manifestations. Diagnosing and treating both early and late endocrine manifestations can dramatically improve the growth, well-being, and quality of life of patients with childhood central nervous system diseases.

  5. An analysis of the differences between early and late preeclampsia with severe hypertension.

    Science.gov (United States)

    Li, X L; Guo, P L; Xue, Y; Gou, W L; Tong, M; Chen, Q

    2016-01-01

    Preeclampsia is clinically divided into early onset and late onset preeclampsia based on the gestational age at delivery. Although the diagnostic criteria are the same in each subgroup of preeclampsia, it has been suggested that the maternal and perinatal mortalities of early onset and late onset preeclampsia are different. However, studies that compare clinical parameters or laboratory biomarkers between early onset and late onset preeclampsia are limited. Data on 177 women with early or late preeclampsia with severe hypertension were collected from a University Teaching Hospital from January 2010 to January 2011 and analysed. Data included all the clinical parameters and laboratory biomarkers of liver and renal function. 63 women and 114 women were diagnosed with early and late preeclampsia with severe hypertension, respectively. There was no difference in the maternal age and the incidence of clinical symptoms including edema, vision disturbance, severe headache and stillbirth between two groups. There was a decrease in alkaline phosphatase levels in early preeclampsia with severe hypertension but other markers of liver function were not altered. However, renal function including blood urea nitrogen, creatinine and uric acid were significantly higher in early preeclampsia with severe hypertension. Umbilical artery systolic velocity/diastolic velocity ratio was significantly higher in early preeclampsia with severe hypertension. Our data demonstrates that the laboratory biomarkers of renal function differ between early and late preeclampsia with severe hypertension. The severity of renal dysfunction correlated with the time of delivery in preeclampsia with severe hypertension. Copyright © 2015 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

  6. Effect of early vs. late tracheostomy on clinical outcomes in critically ill pediatric patients.

    Science.gov (United States)

    Lee, J-H; Koo, C-H; Lee, S-Y; Kim, E-H; Song, I-K; Kim, H-S; Kim, C-S; Kim, J-T

    2016-10-01

    Few studies investigated the optimal timing for tracheostomy and its influence on the clinical outcomes in critically ill pediatric patients. This study evaluated the differences in clinical outcomes between early and late tracheostomy in pediatric intensive care unit (ICU) patients. We assessed 111 pediatric patients. Patients who underwent a tracheostomy within 14 days of mechanical ventilation (MV) were assigned to the early tracheostomy group, whereas those who underwent tracheostomy after 14 days of MV were included in the late tracheostomy group. Clinical outcomes, including mortality, duration of MV, length of ICU and hospital stays, and incidence of ventilator-associated pneumonia (VAP) were compared between the groups. Of the 111 pediatric patients, 61 and 50 were included in the early and late tracheostomy groups, respectively. Total MV duration and the length of ICU and hospital stay were significantly longer in the late tracheostomy group than in the early tracheostomy group (all P tracheostomy was 2.6 and 3.8 in the early and late tracheostomy groups, respectively. There were no significant differences in mortality rate between the groups. No severe complications were associated with tracheostomy itself. Tracheostomy performed within 14 days after the initiation of MV was associated with reduced duration of MV and length of ICU and hospital stay. Although there was no effect on mortality rate, children may benefit from early tracheostomy without severe complications. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  7. Early and Late Recurrent Epistaxis Admissions: Patterns of Incidence and Risk Factors.

    Science.gov (United States)

    Cohen, Oded; Shoffel-Havakuk, Hagit; Warman, Meir; Tzelnick, Sharon; Haimovich, Yaara; Kohlberg, Gavriel D; Halperin, Doron; Lahav, Yonatan

    2017-09-01

    Objective Epistaxis is a common complaint, yet few studies have focused on the incidence and risk factors of recurrent epistaxis. Our objective was to determine the patterns of incidence and risk factors for recurrent epistaxis admission (REA). Study Design Case series with chart review. Settings Single academic center. Subjects and Methods The medical records of patients admitted for epistaxis between 1999 and 2015 were reviewed. The follow-up period was defined as 3 years following initial admission. REAs were categorized as early (30 days) and late (31 days to 3 years) following initial admission. Logistic regression was used to identify potential predictors of REAs. Results A total of 653 patients were included. Eighty-six patients (14%) had REAs: 48 (7.5%) early and 38 (6.5%) late. Nonlinear incidence curve was demonstrated for both early and late REAs. Based on logistic regression, prior nasal surgery and anemia were independent risk factors for early REAs. According to multivariate analysis, thrombocytopenia was significantly associated with late REAs. Conclusion Early and late REAs demonstrate different risk predictors. Knowledge of such risk factors may help in risk stratification for this selected group of patients. All patients at risk should be advised on possible preventive measures. Patients at risk for early REA may benefit from a more proactive approach.

  8. Correlates and prevalence of hypogonadism in patients with early- and late-onset type 2 diabetes.

    Science.gov (United States)

    Li, Y; Zhang, M; Liu, X; Cui, W; Rampersad, S; Li, F; Lin, Z; Yang, P; Li, H; Sheng, C; Cheng, X; Qu, S

    2017-07-01

    This study aims to compare the prevalence of hypogonadism between male patients with early-onset type 2 diabetes mellitus (T2DM) and late-onset type 2 diabetes. A total of 122 male patients with early-onset T2DM (diagnosis age ≤40 years) and 100 male patients with late-onset T2DM (diagnosis age >40 years) were recruited from our in-patient department between 1 January 2013 and 28 December 2015. Serum FSH, LH, testosterone, lipid profile, uric acid, HbA1c, and beta-cell function were determined in blood samples. The diagnosis of hypogonadism was based on the levels of LH, FSH, and total testosterone. The mean onset age was 29.86 ± 6.31 and 54.47 ± 9.97 years old in the early-onset group and late-onset group, respectively. Compared with late-onset T2DM, those with early-onset T2DM had a higher proportion of new-onset diabetes, were more likely to be obese, and had worse glycemic control, lipid control, and lower sex hormone-binding globulin (SHBG). The prevalence of hypogonadism was much higher in the early-onset group than in the late-onset group (48.0% vs. 26.7%, p hypogonadism in the early-onset group and late-onset group were 44.3% and 25.0%, respectively (p hypogonadism was higher in the patients with early-onset T2DM than that of late-onset T2DM. This prevalence might be attributable to greater obesity, worse lipid control, and lower SHBG levels in those patients. © 2017 American Society of Andrology and European Academy of Andrology.

  9. Late lessons from early warnings: science, precaution, innovation

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss

    2013-01-01

    of chemical and technological innovations, and highlight a number of systemic problems. The 'Late Lessons Project' illustrates how damaging and costly the misuse or neglect of the precautionary principle can be, using case studies and a synthesis of the lessons to be learned and applied to maximising...... rather than present specific estimates for these costs. Making the best use of environmental science and modelling helps to make environmental protection and precaution a priority. Producing cost estimates should not be left to economists alone, but should rather be seen as a starting point for a broader...... discussion, featuring also the relevant expertise in health, ecology, demography, modelling and science. Well researched estimates, based on interdisciplinary collaboration, can strengthen some of those scattered and diffuse interests, which during the ordinary processes of policy-making have difficulty...

  10. Understanding the Characteristics of Early and Late Adopters of Technology

    DEFF Research Database (Denmark)

    Tobbin, Peter Ebo; Adjei, Joseph K.

    2012-01-01

    on the existing literature on consumer innovativeness is thus presented. The model is tested via a survey instrument from a population of earlier adopters of mobile money services in Ghana and analyzed using ANOVA and independent sample t-test techniques in SPSS. The results showed that early adopters...

  11. Early and Late Language Start at Private Schools in Turkey

    Science.gov (United States)

    Cepik, Saban; Sarandi, Hedayat

    2012-01-01

    This study examines the interaction effect of age in L2 attainment. It explores whether success in foreign language learning at early childhood grades varies depending on age. It also addresses the beliefs of foreign language teachers regarding the variables under review. Eighty-three 11 year-old language learners who started learning English at…

  12. Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish.

    Science.gov (United States)

    Ingley, Spencer J; Johnson, Jerald B

    2016-03-01

    How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time. © 2016 The Author(s).

  13. Tocuila Mammoths, Basin of Mexico: Late Pleistocene-Early Holocene stratigraphy and the geological context of the bone accumulation

    Science.gov (United States)

    Gonzalez, Silvia; Huddart, David; Israde-Alcántara, Isabel; Dominguez-Vazquez, Gabriela; Bischoff, James

    2014-07-01

    We report new stratigraphic, tephrochronology and dating results from the Tocuila Mammoth site in the Basin of Mexico. At the site there is evidence for a thin meteorite airburst layer dated between 10,878 and 10,707 cal BC at the onset of the Younger Dryas (YD) cool period. The Upper Toluca Pumice (UTP) tephra marker, caused by a Plinian eruption of the Nevado de Toluca volcano, dated from 10,666 to 10,612 cal BC, is above that layer. The eruption must have caused widespread environmental disruption in the region with evidence of extensive reworking and channelling by the Lake Texcoco shoreline and contributed to the widespread death and/or extinction of megafaunal populations, as suggested by earlier authors, but the new work reinforces the view that both catastrophic events must have caused large environmental disruption in a short time period of around two hundred years. There is no evidence for megafauna (mammoths, sabre toothed cats, camels, bison, glyptodonts) after the UTP volcanic event and subsequent lahars in the Basin of Mexico. At Tocuila, although there are some in situ tephra markers in nearshore lake sediments, such as the Great Basaltic Ash (GBA) and the UTP Ash, there is evidence of much reworking of several tephra populations in various combinations. The mammoth bone accumulation is reworked in a lahar sequence (volcanic mudflow) derived from several source sediments but associated with the major UTP Plinian eruption. Paleoindian populations were also present in the Basin of Mexico during the YD period, where several Paleoindian skeletons were found associated with the UTP ash deposits, e.g. Metro Man, Chimalhuacan Man and Tlapacoya Man.

  14. Preventability of early vs. late readmissions in an academic medical center.

    Directory of Open Access Journals (Sweden)

    Kelly L Graham

    Full Text Available It is unclear if the 30-day unplanned hospital readmission rate is a plausible accountability metric.Compare preventability of hospital readmissions, between an early period [0-7 days post-discharge] and a late period [8-30 days post-discharge]. Compare causes of readmission, and frequency of markers of clinical instability 24h prior to discharge between early and late readmissions.120 patient readmissions in an academic medical center between 1/1/2009-12/31/2010.Sum-score based on a standard algorithm that assesses preventability of each readmission based on blinded hospitalist review; average causation score for seven types of adverse events; rates of markers of clinical instability within 24h prior to discharge.Readmissions were significantly more preventable in the early compared to the late period [median preventability sum score 8.5 vs. 8.0, p = 0.03]. There were significantly more management errors as causative events for the readmission in the early compared to the late period [mean causation score [scale 1-6, 6 most causal] 2.0 vs. 1.5, p = 0.04], and these errors were significantly more preventable in the early compared to the late period [mean preventability score 1.9 vs 1.5, p = 0.03]. Patients readmitted in the early period were significantly more likely to have mental status changes documented 24h prior to hospital discharge than patients readmitted in the late period [12% vs. 0%, p = 0.01].Readmissions occurring in the early period were significantly more preventable. Early readmissions were associated with more management errors, and mental status changes 24h prior to discharge. Seven-day readmissions may be a better accountability measure.

  15. Early rising children are more active than late risers

    Directory of Open Access Journals (Sweden)

    Jun Kohyama

    2007-01-01

    Full Text Available Jun KohyamaDepartment of Pediatrics, Tokyo Kita Shakai Hoken Hospital, Tokyo, JapanBackground: A low level of physical activity impacts mental as well as physical health. This study investigated the daily lifestyle habits that affect physical activity in young children.Methods: The relationship between physical activity, assessed by means of a Mini-Mitter Actiwatch device, and observed daily lifestyle habits was analyzed for 204 children, aged 12 to 40 months (average: 22.6 months, for whom 6-consecutive-day data from both the Actiwatch and sleep log were obtained.Results: An older age, male gender, and early waking time showed significant positive correlations with physical activity level. Multiple regression analysis revealed that these three variables were significant predictors of physical activity.Conclusion: Promoting an early rising time is suggested to be an important element of cultivating good health in young children.Keywords: physical activity, children, actigraphy, morning light

  16. Final Pleistocene and Early Holocene at Sitio do Meio, Piauí, Brazil: Stratigraphy and comparison with Pedra Furada

    Directory of Open Access Journals (Sweden)

    Giulia Aimola

    2014-09-01

    Full Text Available English: Sitio do Meio, in southern Piaui, Brazil, is the second rock shelter presenting fully Pleistocene dates and artefacts after Pedra Furada.  Despite the anthropogenic origin of Pedra Furada artefacts has been questioned, SDM has better chances to be accepted by the scientific community because of the absence of the most relevant stone breaking agents in this kind of site, i.e. waterfalls. This paper presents a critical revision of the history of excavations (1980-2000, stratigraphy, chronology, and the archaeological content of the site (sector 2. At least 98 stone tools have been identified and described, all of them being older than 12,500 BP, i.e. belonging to the Upper Pleistocenic phase of Pedra Furada 3, as defined in the close reference site. The lithic industry of Serra Talhada phase (lower Holocene is also presented and compared with paleoindian sites of North-Eastern and Central Brazil.French:Le Sitio do meio, dans le  Piaui méridional (Brésil est le deuxième abri sous roche de la région ayant livré des dates pléistocènes en dehors du site de la Pedra Furada. L'article présente une révision critique des fouilles (1980-2000, la chronostratigraphie et le contenu archéologique du secteur 2. Une centaine d'outils lithiques sont décrits, ils sont plus anciens de 12,5 ka BP  et correspondent à la phase Pléistocène Pedra Furada 3 définie dans le site éponyme de référence. On présente aussi l' industrie lithique de la phase Serra Talhada (Holocène  ancien en la comparant aux industries paléoindiennes du Nord-Est et du centre du Brésil.

  17. Mid-Pliocene to Early Pleistocene land and sea surface temperature history of NW Australia based on organic geochemical proxies

    Science.gov (United States)

    Smith, R. A.; Castañeda, I. S.; Henderiks, J.; Christensen, B. A.; De Vleeschouwer, D.; Renema, W.; Groeneveld, J.; Bogus, K.; Gallagher, S. J.; Fulthorpe, C.; Expedition 356 Scientists, I.

    2017-12-01

    IODP Expedition 356 Site U1463 is located off the coast of NW Australia, and is sensitive to Indonesian Throughflow (ITF) variability. The ITF is a critical ocean gateway that affects global thermohaline circulation, and regulates the movement of water from the Pacific Ocean into the Indian Ocean. However, despite its importance to the global climate system, few SST reconstructions exist for this region that span the Plio-Pleistocene. Here we investigate both the land and sea-surface temperature (SST) history of NW Australia to constrain ITF variability across the Plio-Pleistocene interval. We apply multiple organic geochemical proxies to this site from 3.4-2.6 Ma, which includes the mid-Pliocene warm period, characterized by slightly higher (2-3°C) global temperatures and similar CO2 concentrations to modern values (e.g. Badger et al. 2013; Bartoli et al., 2011; Dowsett et al., 2009; Hönisch et al., 2009; Pagani et al. 2009; Raymo et al., 1996). SST was reconstructed using TEX86, based on isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs), and the long-chain diol index (LDI), based on the ratio of diols produced by marine diatoms (Rampen et al., 2012). The Uk'37 index, based on long-chain ketones, was analyzed but cannot be applied as a SST proxy at this site due to the influence of coastal alkenone producers. Additionally, a continental air temperature record was developed using the MBT'5ME proxy, based on branched GDGTs (De Jonge et al., 2014; Weijers et al., 2007). We find that TEX86, LDI and MBT'5Me exhibit similar trends and show relatively warm and stable temperatures from 3.5-2.4 Ma followed by a gradual cooling of 3-4°C from 2.4-1.5 Ma. This cooling corresponds with an arid interval previously identified on the same core by Christensen et al. (2017). Furthermore, we find that the TEX86 record agrees closely with the LR04 global benthic δ18O stack (Lisiecki and Raymo, 2005) and captures glacial/interglacial periods including Marine Isotope Stage

  18. Consequences of repeated ethanol exposure during early or late adolescence on conditioned taste aversions in rats

    Directory of Open Access Journals (Sweden)

    Jessica Saalfield

    2015-12-01

    Full Text Available Alcohol use is prevalent during adolescence, yet little is known about possible long-lasting consequences. Recent evidence suggests that adolescents are less sensitive than adults to ethanol's aversive effects, an insensitivity that may be retained into adulthood after repeated adolescent ethanol exposure. This study assessed whether intermittent ethanol exposure during early or late adolescence (early-AIE or late-AIE, respectively would affect ethanol conditioned taste aversions 2 days (CTA1 and >3 weeks (CTA2 post-exposure using supersaccharin and saline as conditioning stimuli (CS, respectively. Pair-housed male Sprague-Dawley rats received 4 g/kg i.g. ethanol (25% or water every 48 h from postnatal day (P 25–45 (early AIE or P45-65 (late AIE, or were left non-manipulated (NM. During conditioning, 30 min home cage access to the CS was followed by 0, 1, 1.5, 2 or 2.5 g/kg ethanol i.p., with testing 2 days later. Attenuated CTA relative to controls was seen among early and late AIE animals at both CTA1 and CTA2, an effect particularly pronounced at CTA1 after late AIE. Thus, adolescent exposure to ethanol was found to induce an insensitivity to ethanol CTA seen soon after exposure and lasting into adulthood, and evident with ethanol exposures not only early but also later in adolescence.

  19. Consequences of repeated ethanol exposure during early or late adolescence on conditioned taste aversions in rats.

    Science.gov (United States)

    Saalfield, Jessica; Spear, Linda

    2015-12-01

    Alcohol use is prevalent during adolescence, yet little is known about possible long-lasting consequences. Recent evidence suggests that adolescents are less sensitive than adults to ethanol's aversive effects, an insensitivity that may be retained into adulthood after repeated adolescent ethanol exposure. This study assessed whether intermittent ethanol exposure during early or late adolescence (early-AIE or late-AIE, respectively) would affect ethanol conditioned taste aversions 2 days (CTA1) and >3 weeks (CTA2) post-exposure using supersaccharin and saline as conditioning stimuli (CS), respectively. Pair-housed male Sprague-Dawley rats received 4g/kg i.g. ethanol (25%) or water every 48 h from postnatal day (P) 25-45 (early AIE) or P45-65 (late AIE), or were left non-manipulated (NM). During conditioning, 30 min home cage access to the CS was followed by 0, 1, 1.5, 2 or 2.5g/kg ethanol i.p., with testing 2 days later. Attenuated CTA relative to controls was seen among early and late AIE animals at both CTA1 and CTA2, an effect particularly pronounced at CTA1 after late AIE. Thus, adolescent exposure to ethanol was found to induce an insensitivity to ethanol CTA seen soon after exposure and lasting into adulthood, and evident with ethanol exposures not only early but also later in adolescence. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. The early Pleistocene deciduous hominid molar FS-72 from the Sangiran Dome of Java, Indonesia: A taxonomic reappraisal based on its comparative endostructural characterization.

    Science.gov (United States)

    Zanolli, Clément; Grine, Frederick E; Kullmer, Ottmar; Schrenk, Friedemann; Macchiarelli, Roberto

    2015-08-01

    Among the ten fossil hominid deciduous teeth reported so far from the Pleistocene sediments of the Sangiran Dome of Java are two isolated lower second molars: specimens PCG.2 from the Kabuh Formation and FS-72 from the Pucangan Formation. While PCG.2 appears to be certainly attributable to Homo erectus, FS-72 is somewhat more problematic, even though it is commonly listed within the Indonesian H. erectus hypodigm. Largely because of its large size, it was originally attributed to Meganthropus paleojavanicus. Subsequent study highlighted a set of metric and nonmetric crown features also found in Australopith and African early Homo (notably H. habilis) homologues. An additional problem with the taxonomic assignment of isolated teeth from the Pleistocene of Java is the presence of Pongo in these same deposits. To assess the taxonomic affinity of FS-72, we investigated its inner structure (tissue proportions and enamel-dentine junction morphology) by using techniques of 2-3D virtual imaging coupled with geometric morphometric analyses. The results show that FS-72 has thinner enamel compared to fossil and recent humans and that its topographic repartition more closely follows the pongine pattern. It also exhibits a Pongo-like elongated morphology of the enamel-dentine junction, with proportionally lower and mesiodistally spaced dentine horns. Given the morphological and metric similarities between fossil orangutan and H. erectus molars, we tested the hypothesis that its internal morphology more closely resembles the patterns evinced by PCG.2 and modern humans than Pongo. Accordingly, we consider that FS-72 more likely represents a dm2 of Pongo rather than Homo. © 2015 Wiley Periodicals, Inc.

  1. New foot remains from the Gran Dolina-TD6 Early Pleistocene site (Sierra de Atapuerca, Burgos, Spain).

    Science.gov (United States)

    Pablos, Adrián; Lorenzo, Carlos; Martínez, Ignacio; Bermúdez de Castro, José María; Martinón-Torres, María; Carbonell, Eudald; Arsuaga, Juan Luis

    2012-10-01

    This paper presents and describes new foot fossils from the species Homo antecessor, found in level TD6 of the site of Gran Dolina (Sierra de Atapuerca, Burgos, Spain). These new fossils consist of an almost complete left talus (ATD6-95) and the proximal three-quarters of a right fourth metatarsal (ATD6-124). The talus ATD6-95 is tentatively assigned to Hominin 10 of the TD6 sample, an adult male specimen with which the second metatarsal ATD6-70+107 (already published) is also tentatively associated. Analysis of these fossils and other postcranial remains has made possible to estimate a stature similar to those of the specimens from the Middle Pleistocene site of Sima de los Huesos (Sierra de Atapuerca, Burgos, Spain). The morphology of the TD6 metatarsals does not differ significantly from that of modern humans, Neanderthals and the specimens from Sima de los Huesos. Talus ATD6-95, however, differs from the rest of the comparative samples in being long and high, having a long and wide trochlea, and displaying a proportionally short neck. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Rats' learned preferences for flavors encountered early or late in a meal paired with the postingestive effects of glucose.

    Science.gov (United States)

    Myers, Kevin P; Whitney, Margaret C

    2011-03-28

    Rats learn to prefer flavors that are followed by postingestive effects of nutrients. This experiment investigated whether the timing of a flavor (specifically, in the first or second half of the meal) influences learning about that flavor. Stronger learning about earlier or later flavors would indicate when the rewarding postingestive effects of nutrients are sensed. Rats with intragastric (IG) catheters drank saccharin-sweetened, calorically-dilute solutions with distinct flavors added, accompanied by IG infusion of glucose (+sessions) or water (-sessions). In both types of sessions, an "Early" flavor was provided for the first 8 min and a "Late" flavor for the last 8 min. Thus, rats were trained with Early(+) and Late(+) in high-calorie meals, and Early(-) and Late(-) in low-calorie meals. Strength of the learned preference for Early(+) and Late(+) was then assessed in a series of two-bottle choice tests between Early(+) vs. Early(-), Late(+) vs. Late(-), Early(+) vs. Late(+), and Early(-) vs. Late(-). Rats preferred both Early(+) and Late(+) over the respective (-) flavors. But Early(+) was only preferred when rats were tested hungry. Late(+) was preferred when rats were tested hungry or recently satiated. This indicates qualitatively different associations learned about flavors at different points in the meal. While not supporting the idea that postingestive effects become most strongly associated with later-occurring ("dessert") flavors, it does suggest a reason dessert flavors may remain attractive in the absence of hunger. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Early and Late Side Effects Associated with Photo(chemotherapy

    Directory of Open Access Journals (Sweden)

    Günseli Öztürk

    2010-12-01

    Full Text Available Phototherapy (PUVA ve UVB is a widely used and effective treatment method for a variety of dermatological diseases. Adverse effects associated with phototherapy can be classified as acute and chronic side effects. Acute side effects are mostly related with UV doses and drug intolerance, and include itching, nausea, erythema, edema and phototoxic reactions that sometimes blister formation is seen. Acute side effects are usually moderate and transient. Chronic side effects of phototherapy are early aging of skin, pigmentary changes and increased risk of skin carcinogenesis. The major concern is development of skin cancer. This risk is especially related to long-term exposure and high cumulative doses of PUVA, increase in time and is persistent. Therefore, risk/advantage ratio of phototherapy should be carefully evaluated in each patient, and treatment protocols with minimal UV exposure should be chosen according to the phototherapy guides. Follow-up of the patients for long terms is important in prevention or in reduction of this risk by detecting and treating any premalignant or malignant lesion early. In this article, acute and chronic side effects of phototherapy are reviewed with recent literature findings.

  4. Overview of the Plio-Pleistocene geology of Rhodes, Greece. Lithology, calcareous nannofossil biostratigraphy, and sampling of the Kallithea Bay section

    DEFF Research Database (Denmark)

    Thomsen, Erik; Rasmussen, Tine Lander; Hastrup, Annette

    2005-01-01

    -water deposits are assigned to the Lindos Bay clay. Calcareous nannofossil biostratigraphy shows that the age of the marine sequence is early Pleistocene. The brackish water sediments are difficult to date, but they are probably of late Pliocene age. Sixty-nine samples representing all environments were...

  5. Study on the early and late mutants of radiation induced rice

    International Nuclear Information System (INIS)

    Yang Hefeng; Chen Xiulan; He Zhentian; Gu Shiliang; Xu Chenwu

    1990-12-01

    After three years of consecutive experiments for the irradiated M 2 generations of 53 different varieties of rice, the following results have been obtained: (1) The average of early mutant plant rate is 1.4%. The rate in the early-maturing varieties is lower than that in the late-maturing varieties. It is in proportion to the length of growing period of these varieties tested. The shortened days of growing period of early mutants are 3 to 32 days (the average was 9.5 days), and it is increasing as the growing period increases. (2) In the irradiated M 2 generation of same variety, the early mutants and late mutants could be simultaneously happened, but the rate of the late mutants is 2.67%, which is higher than the rate of early mutants (1.39%). The shortened and prolonged days of growing period are 11.5 and 10.5 days respectively. These early and late mutants have some changes, both good and bad, in agronomical traits such as plant height, weight per kilo-grains and grains number per tassel. In some extent these changes are significant

  6. THE ENVIRONMENTAL DEPENDENCE OF THE FRACTION OF 'UNCONVENTIONAL' GALAXIES: RED LATE TYPES AND BLUE EARLY TYPES

    International Nuclear Information System (INIS)

    Deng Xinfa; He Jizhou; Wu Ping; Ding Yingping

    2009-01-01

    From the Main galaxy sample of the Sloan Digital Sky Survey Data Release 6, we construct two volume-limited samples with the luminosity -20.0 ≤ M r ≤ -18.5 and -22.40 ≤ M r ≤ -20.16, respectively, to explore the environmental dependence of the fraction of 'unconventional' galaxies: red late types and blue early types. We use the density estimator within the distance to the fifth nearest neighbor, and construct two samples at both extremes of density and perform comparative studies between them for each volume-limited sample. Results of two volume-limited samples show the same conclusions: the fraction of red late-type galaxies rises considerably with increasing local density, and that one of the blue early-type galaxies declines substantially with increasing local density. In addition, we note that bluer galaxies preferentially are late types, but the red galaxies are not dominated by early types.

  7. The role of repopulation in early and late radiation reactions in pig skin

    International Nuclear Information System (INIS)

    Redpath, J.L.; Peel, D.M.; Dodd, P.; Simmonds, R.H.; Hopewell, J.W.

    1984-01-01

    The role of repopulation in early and late radiation reactions in pig skin has been assessed by comparing split dose recovery doses (D/sub 2/-D/sub 1/) for a 1-day interval and a 28-day interval. For a 1-day interval, repair of sublethal damage is the major contribution to any recovery observed, whereas for a 28-day interval, repopulation may also play a role. The early reaction studied was moist desquamation and the late reactions studied were a later dermal erythema and necrosis. The data show that over a 28-day interval, repopulation contributes -- 7.0 Gy to a total D/sub 2/-D/sub 1/, of --14.0 Gy for the early moist desquamation (epidermal) reaction. Data for the role of repopulation in the late (dermal) reactions are also presented

  8. Differences between early and late onset adult depression

    DEFF Research Database (Denmark)

    Drachmann Bukh, Jens; Bock, Camilla; Vinberg, Maj

    2011-01-01

    episode depression were systematically recruited. Characteristics including psychiatric co-morbidity, personality disorders and traits, stressful life events prior to onset, family history, and treatment outcome were assessed by structured interviews and compared by chi-square tests for categorical data...... prevalence of co-morbid personality disorders, higher levels of neuroticism, and a lower prevalence of stressful life events preceding onset compared to patients with later age-of-onset. There were no differences in severity of the depressive episode, treatment outcome or family loading of psychiatric......, t-tests for continuous parametric data and Mann-Whitney U-test for continuous nonparametric data. Logistic and multiple regression analyses were used to adjust the analyses for potentially confounding variables. Results: Patients with early onset of depression were characterised by a higher...

  9. Maternal circulating leukocytes display early chemotactic responsiveness during late gestation

    Directory of Open Access Journals (Sweden)

    Gomez-Lopez Nardhy

    2013-01-01

    Full Text Available Abstract Background Parturition has been widely described as an immunological response; however, it is unknown how this is triggered. We hypothesized that an early event in parturition is an increased responsiveness of peripheral leukocytes to chemotactic stimuli expressed by reproductive tissues, and this precedes expression of tissue chemotactic activity, uterine activation and the systemic progesterone/estradiol shift. Methods Tissues and blood were collected from pregnant Long-Evans rats on gestational days (GD 17, 20 and 22 (term gestation. We employed a validated Boyden chamber assay, flow cytometry, quantitative real time-polymerase chain reaction, and enzyme-linked immunosorbent assays. Results We found that GD20 maternal peripheral leukocytes migrated more than those from GD17 when these were tested with GD22 uterus and cervix extracts. Leukocytes on GD20 also displayed a significant increase in chemokine (C-C motif ligand 2 (Ccl2 gene expression and this correlated with an increase in peripheral granulocyte proportions and a decrease in B cell and monocyte proportions. Tissue chemotactic activity and specific chemokines (CCL2, chemokine (C-X-C motif ligand 1/CXCL1, and CXCL10 were mostly unchanged from GD17 to GD20 and increased only on GD22. CXCL10 peaked on GD20 in cervical tissues. As expected, prostaglandin F2α receptor and oxytocin receptor gene expression increased dramatically between GD20 and 22. Progesterone concentrations fell and estradiol-17β concentrations increased in peripheral serum, cervical and uterine tissue extracts between GD20 and 22. Conclusion Maternal circulating leukocytes display early chemotactic responsiveness, which leads to their infiltration into the uterus where they may participate in the process of parturition.

  10. Effect of early and late mobilisation on split skin graft outcome.

    Science.gov (United States)

    Luczak, Bernard; Ha, Jennifer; Gurfinkel, Reuven

    2012-02-01

    There is an increasing trend towards early mobilisation post-split skin grafting of the lower limbs. This study was performed to determine if early mobilisation impacts negatively on graft healing and patient morbidity. A retrospective review of 48 cases of lower limb split skin grafts performed by the plastic surgery department at Royal Perth Hospital was undertaken. Patients were stratified into early and late mobilisation groups. No difference in outcome was identified with early mobilisation, but an increased rate of deconditioning with increased length of stay was present with late mobilisation. These results suggest that early mobilisation post-split skin grafting of the lower limb is beneficial to patient care and is associated with lower morbidity. © 2011 The Authors. Australasian Journal of Dermatology © 2011 The Australasian College of Dermatologists.

  11. Accuracy of different diagnostic tests for early, delayed and late prosthetic joint infection.

    Science.gov (United States)

    Fernández-Sampedro, M; Fariñas-Alvarez, C; Garces-Zarzalejo, C; Alonso-Aguirre, M A; Salas-Venero, C; Martínez-Martínez, L; Fariñas, M C

    2017-08-25

    A combination of laboratory, histopathological and microbiological tests for diagnosis of prosthetic joint infection (PJI) have been strongly recommended. This study aims to characterize the accuracy of individual or group tests, such as culture of sonicate fluid, synovial fluid and peri-implant tissue, C-reactive protein (CRP) and histopathology for detection of early, delayed and late PJI. A prospective study of patients undergoing hip or knee arthroplasty from February 2009 to February 2014 was performed in a Spanish tertiary health care hospital. The diagnostic accuracy of the different methods was evaluated constructing receiver-operating-characteristic (ROC) curve areas. One hundred thirty consecutive patients were included: 18 (13.8%) early PJI, 35 (27%) delayed PJI and 77 (59.2%) late PJI. For individual parameters, the area under the ROC curve for peri-implant tissue culture was larger for early (0.917) than for delayed (0.829) and late PJI (0.778), p = 0.033. There was a significantly larger difference for ROC area in the synovial fluid culture for delayed (0.803) than for early (0.781) and late infections (0.679), p = 0.039. The comparison of the areas under the ROC curves for the two microbiological tests showed that sonicate fluid was significantly different from peri-implant tissue in delayed (0.951 vs 0.829, p = 0.005) and late PJI (0.901 vs 0.778, p = 0.000). The conjunction of preoperative parameters, synovial fluid culture and CRP, improved the accuracy for late PJI (p = 0.01). The conjunction of histopathology and sonicate fluid culture increased the area under ROC curve of sonication in early (0.917 vs 1.000); p = 0.06 and late cases (0.901 vs 0.999); p < 0.001. For early PJI, sonicate fluid and peri-implant tissue cultures achieve the same best sensitivity. For delayed and late PJI, sonicate fluid culture is the most sensitive individual diagnostic method. By combining histopathology and peri-implant tissue, all early, 97% of

  12. Characterization of Early and Late Adopters of ATM Card in Indian Banking Industry

    Directory of Open Access Journals (Sweden)

    Kamalpreet Kaur

    2012-10-01

    Full Text Available The present study deals with affect of adoption pattern of the ATMs by banks on its characteristics. With the exploration of various characteristics of the banks like Size, Profi tability, Efficiency, Cost of Operations, Asset quality and Credit risk, Financing Pattern, Diversifi cation and Age etc.; the study has tried to differentiate between the early and late adopter category of the banks regarding ATM cards. The banks have been categorized into early and late adopters on the basis of their adoption period. For this purpose, 50 scheduled commercial banks consisting of 27 Public Sector Banks and 23 Private Sector Banks have been taken as sample to investigate the various aspects of and early adopter banks in comparison to late adopter banks. The time period of the study is 20 years i.e. from 1991 to 2010. It can be concluded that the initiators and fi rst movers take advantage over the late adopters and laggards. They have found to perform better in terms of various parameters. Overall, the early adopter banks are larger in size, more diversifi ed, having lesser branches, more market share and wide ATM network as compared to late adopter ones. Thus, the empirical results evidently reveal that the both the groups have their own different characteristics.

  13. Discrete β-adrenergic mechanisms regulate early and late erythropoiesis in erythropoietin-resistant anemia.

    Science.gov (United States)

    Hasan, Shirin; Mosier, Michael J; Szilagyi, Andrea; Gamelli, Richard L; Muthumalaiappan, Kuzhali

    2017-10-01

    Anemia of critical illness is resistant to exogenous erythropoietin. Packed red blood cells transfusions is the only treatment option, and despite related cost and morbidity, there is a need for alternate strategies. Erythrocyte development can be divided into erythropoietin-dependent and erythropoietin-independent stages. We have shown previously that erythropoietin-dependent development is intact in burn patients and the erythropoietin-independent early commitment stage, which is regulated by β1/β2-adrenergic mechanisms, is compromised. Utilizing the scald burn injury model, we studied erythropoietin-independent late maturation stages and the effect of β1/β2, β-2, or β-3 blockade in burn mediated erythropoietin-resistant anemia. Burn mice were randomized to receive daily injections of propranolol (nonselective β1/β2 antagonist), nadolol (long-acting β1/β2 antagonist), butoxamine (selective β2 antagonist), or SR59230A (selective β3 antagonist) for 6 days after burn. Total bone marrow cells were characterized as nonerythroid cells, early and late erythroblasts, nucleated orthochromatic erythroblasts and enucleated reticulocyte subsets using CD71, Ter119, and Syto-16 by flow cytometry. Multipotential progenitors were probed for MafB expressing cells. Although propranolol improved early and late erythroblasts, only butoxamine and selective β3-antagonist administrations were positively reflected in the peripheral blood hemoglobin and red blood cells count. While burn impeded early commitment and late maturation stages, β1/β2 antagonism increased the early erythroblasts through commitment stages via β2 specific MafB regulation. β3 antagonism was more effective in improving overall red blood cells through late maturation stages. The study unfolds novel β2 and β3 adrenergic mechanisms orchestrating erythropoietin resistant anemia after burn, which impedes both the early commitment stage and the late maturation stages, respectively. Copyright © 2017

  14. [Intrauterine devices in the immediate, early and late postabortion period].

    Science.gov (United States)

    Nun, S

    1971-01-01

    2146 cases of IUD insertions after hospitalization for abortion at a hospital in Chile were studied. In 1514 cases the IUDs were inserted immediately after abortion, in 430 cases between 1-5 days after the operation, and in 202 cases between 5-40 days after. It is concluded that immediate or early insertion results in a somewhat lower retention rate, but offers the advantage of making it possible to treat a greater number of patients, many of whom would not return later to have the IUD inserted. The incidence of removal for medical causes was very low and immediate insertion was found to be harmless. The medical causes of removal were the usual ones of bleeding, pain, and infection; the most frequent cause of interruption of use was expulsion, which tends to occur during the 1st few months of use and among younger women. The probability of failure due to pregnancy was somewhat higher than in the case of insertion during the intermenstrual period. Cases of voluntary removal tend to increase after prolonged use, and a study to analyze the actual reasons for this fact is necessary.

  15. Repopulation in irradiated pig skin: late versus early effects

    International Nuclear Information System (INIS)

    Redpath, J.L.; Peel, D.M.; Dodd, P.; Simmonds, R.H.; Hopewell, J.W.

    1985-01-01

    In the first 16 weeks after irradiation, two distinct waves of reaction can be observed in pig skin, the first wave (3-9 weeks) represents the expression of damage to the epithelium while the second is indicative of primary damage to the dermis, mediated through vascular injury. Comparison of single doses with two equal doses separated by 28 days produced a D 2 -D 1 value of 14.0 Gy at the doses which produced moist desquamation in 50% of fields (ED 50 ) after strontium-90 irradiation. After X-irradiation, comparison of ED 50 doses for the later dermal reaction suggested a D 2 -D 1 value of 4.2 Gy. These values of D 2 -D 1 for epithelial and dermal reactions in pig skin were compared with earlier data from this laboratory for similar split-dose experiments with a one-day interval. Such a comparison allowed for the estimation of the component of recovery in the present 28-day interval experiments due to repopulation. This component was found to be 6.5 Gy for the early epithelial damage, but was zero for the later dermal damage. (Auth.)

  16. Comparison of early and late MRI in neonatal hypoxic-ischemic encephalopathy using three assessment methods

    International Nuclear Information System (INIS)

    Charon, Valerie; Proisy, Maia; Bruneau, Bertrand; Treguier, Catherine; Rozel, Celine; Ferre, Jean-Christophe; Beuchee, Alain; Chauvel, Jennifer

    2015-01-01

    There is no consensus on the optimum timing of MRI in neonates with hypoxic-ischemic encephalopathy treated with hypothermia. Reliable early imaging assessment might help managing treatment. To assess non-random differences between early and late MRI that might influence intensive-care decisions. This single-center retrospective study included all asphyxiated term neonates eligible for hypothermia treatment November 2009-July 2012. MRI scans were systematically performed at day 4 (early MRI) and day 11 of life as part of routine protocol. Two experienced pediatric radiologists reviewed both scans according to three assessment methods: a pattern classification, a scoring system and a simplified classification. Agreement between early and late imaging findings was assessed using Cohen's kappa coefficients. Thirty-three neonates were included. Interobserver agreement was excellent. Early MRI detected all severe injuries. Agreement between early and late MRI was excellent for the simplified classification (κ = 0.82), good for the pattern classification (κ = 0.64), and good to excellent for 3 scores out of 4 in the scoring system (κ = 0.70-0.89). Early MRI may provide valuable information about brain injury to help parents and neonatologists in intensive-care decisions at the end of hypothermia treatment. (orig.)

  17. Comparison of early and late MRI in neonatal hypoxic-ischemic encephalopathy using three assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Charon, Valerie; Proisy, Maia; Bruneau, Bertrand; Treguier, Catherine; Rozel, Celine [University Hospital, Department of Imaging, Hopital Sud, Rennes, Cedex 2 (France); Ferre, Jean-Christophe [University Hospital, Department of Neuroradiology, Hopital Pontchaillou, Rennes (France); Beuchee, Alain [University Hospital, Department of Neonatology, Hopital Sud, Rennes (France); Chauvel, Jennifer [Saint Brieuc Hospital, Department of Neonatology, Saint-Brieuc (France)

    2015-12-15

    There is no consensus on the optimum timing of MRI in neonates with hypoxic-ischemic encephalopathy treated with hypothermia. Reliable early imaging assessment might help managing treatment. To assess non-random differences between early and late MRI that might influence intensive-care decisions. This single-center retrospective study included all asphyxiated term neonates eligible for hypothermia treatment November 2009-July 2012. MRI scans were systematically performed at day 4 (early MRI) and day 11 of life as part of routine protocol. Two experienced pediatric radiologists reviewed both scans according to three assessment methods: a pattern classification, a scoring system and a simplified classification. Agreement between early and late imaging findings was assessed using Cohen's kappa coefficients. Thirty-three neonates were included. Interobserver agreement was excellent. Early MRI detected all severe injuries. Agreement between early and late MRI was excellent for the simplified classification (κ = 0.82), good for the pattern classification (κ = 0.64), and good to excellent for 3 scores out of 4 in the scoring system (κ = 0.70-0.89). Early MRI may provide valuable information about brain injury to help parents and neonatologists in intensive-care decisions at the end of hypothermia treatment. (orig.)

  18. Early death, late death and repair factor in three human tumour cell lines

    International Nuclear Information System (INIS)

    Courdi, A.; Gioanni, J.; Mari, D.; Chauvel, P.

    1997-01-01

    The in vivo colony method used to generate survival curves following exposure to ionizing irradiation allows to score large clones, representing surviving cells, and small colonies, representing late reproductive death. By subtraction, early-dying cells can be estimated. In the three human tumour cell lines examined, we have observed that early cell death is a major mode of action of irradiation. The contribution of early cell death to total mortality increases as the dose increases. Moreover, repair due to dose-splitting and delayed plating in densely-inhibited cells is not observed in early-dying cells. (authors)

  19. Does the Length of Fielding Period Matter? Examining Response Scores of Early Versus Late Responders

    Directory of Open Access Journals (Sweden)

    Sigman Richard

    2014-12-01

    Full Text Available This article discusses the potential effects of a shortened fielding period on an employee survey’s item and index scores and respondent demographics. Using data from the U.S. Office of Personnel Management’s 2011 Federal Employee Viewpoint Survey, we investigate whether early responding employees differ from later responding employees. Specifically, we examine differences in item and index scores related to employee engagement and global satisfaction. Our findings show that early responders tend to be less positive, even after adjusting their weights for nonresponse. Agencies vary in their prevalence of late responders, and score differences become magnified as this proportion increases. We also examine the extent to which early versus late responders differ on demographic characteristics such as grade level, supervisory status, gender, tenure with agency, and intention to leave, noting that nonminorities and females are the two demographic characteristics most associated with responding early.

  20. Early versus late GD-DTPA MRI enhancement in experimental glioblastomas.

    Science.gov (United States)

    Farace, Paolo; Tambalo, Stefano; Fiorini, Silvia; Merigo, Flavia; Daducci, Alessandro; Nicolato, Elena; Conti, Giamaica; Degrassi, Anna; Sbarbati, Andrea; Marzola, Pasquina

    2011-03-01

    To compare early versus late enhancement in two glioblastoma models characterized by different infiltrative/edematous patterns. Three weeks after inoculation into nude mice of U87MG and U251 cells, T1-weighted images were acquired early (10.5 min), intermediate (21 min) and late (30.5 min) after a bolus injection of Gd-DTPA at 300 μ mol/kg dosage. EARLY(TH) and LATE(TH) were the corresponding volumes with an enhancement higher than a threshold TH, defined by the mean (μ) and standard deviation (σ) on a contralateral healthy area. ADD(TH) was the enhancing volume found in LATE(TH) but not in EARLY(TH). T2 imaging of both tumors was performed, and T2 mapping of U251. In all tumors, LATE(TH) was significantly higher than EARLY(TH) for TH ranging from μ+σ to μ+5σ. The ADD(TH) /EARLY(TH) ratio was not significantly different when U251 and U87MG tumors were compared. In the U87MG tumors, some enhancement was observed outside the regularly demarcated T2-hyperintense area. In the U251 tumors, irregularly T2 demarcated, a large portion of ADD(μ+3σ) had normal T2 values. At histology, U251 showed a higher infiltrative pattern than U87MG. In these models, the increase over time in the enhancing volume did not depend on the different infiltrative/edematous patterns and was not closely related with edema. Copyright © 2011 Wiley-Liss, Inc.

  1. Asymptomatic bacteriuria & obstetric outcome following treatment in early versus late pregnancy in north Indian women

    OpenAIRE

    Jain, Vaishali; Das, Vinita; Agarwal, Anjoo; Pandey, Amita

    2013-01-01

    Background & objectives: Asymptomatic bacteriuria during pregnancy if left untreated, may lead to acute pyelonephritis, preterm labour, low birth weight foetus, etc. Adequate and early treatment reduces the incidence of these obstetric complications. The present study was done to determine presence of asymptomatic bacteriuria (ASB) and obstetric outcome following treatment in early versus late pregnancy. Methods: A prospective cohort study was conducted at a tertiary care teaching hospital of...

  2. Differentiation of Siberian Miners’ Salaries in Late XIX – Early XX Centuries

    Directory of Open Access Journals (Sweden)

    Vasiliy P. Zinovyev

    2014-06-01

    Full Text Available The work considers seasonal variations and differentiation of Siberian miners’ salaries in late XIX – early XX centuries, proves that seasonal variations of salaries depended on the excess demand on labor in summer and the contraction of demand in winter, detects that salary differentiated, depending on workers’ qualification, sex, age, nationality, industry, location of an enterprise. Such differences in Siberian miners’ salaries were typical for early industrial period of the development of the society.

  3. Group relationships in early and late sessions and improvement in interpersonal problems.

    Science.gov (United States)

    Lo Coco, Gianluca; Gullo, Salvatore; Di Fratello, Carla; Giordano, Cecilia; Kivlighan, Dennis M

    2016-07-01

    Groups are more effective when positive bonds are established and interpersonal conflicts resolved in early sessions and work is accomplished in later sessions. Previous research has provided mixed support for this group development model. We performed a test of this theoretical perspective using group members' (actors) and aggregated group members' (partners) perceptions of positive bonding, positive working, and negative group relationships measured early and late in interpersonal growth groups. Participants were 325 Italian graduate students randomly (within semester) assigned to 1 of 16 interpersonal growth groups. Groups met for 9 weeks with experienced psychologists using Yalom and Leszcz's (2005) interpersonal process model. Outcome was assessed pre- and posttreatment using the Inventory of Interpersonal Problems, and group relationships were measured at Sessions 3 and 6 using the Group Questionnaire. As hypothesized, early measures of positive bonding and late measures of positive working, for both actors and partners, were positively related to improved interpersonal problems. Also as hypothesized, late measures of positive bonding and early measures of positive working, for both actors and partners, were negatively related to improved interpersonal problems. We also found that early actor and partner positive bonding and negative relationships interacted to predict changes in interpersonal problems. The findings are consistent with group development theory and suggest that group therapists focus on group-as-a-whole positive bonding relationships in early group sessions and on group-as-a-whole positive working relationships in later group sessions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. Cardioprotective effects of early and late aerobic exercise training in experimental pulmonary arterial hypertension.

    Science.gov (United States)

    Moreira-Gonçalves, Daniel; Ferreira, Rita; Fonseca, Hélder; Padrão, Ana Isabel; Moreno, Nuno; Silva, Ana Filipa; Vasques-Nóvoa, Francisco; Gonçalves, Nádia; Vieira, Sara; Santos, Mário; Amado, Francisco; Duarte, José Alberto; Leite-Moreira, Adelino F; Henriques-Coelho, Tiago

    2015-11-01

    Clinical studies suggest that aerobic exercise can exert beneficial effects in pulmonary arterial hypertension (PAH), but the underlying mechanisms are largely unknown. We compared the impact of early or late aerobic exercise training on right ventricular function, remodeling and survival in experimental PAH. Male Wistar rats were submitted to normal cage activity (SED), exercise training in early (EarlyEX) and in late stage (LateEX) of PAH induced by monocrotaline (MCT, 60 mg/kg). Both exercise interventions resulted in improved cardiac function despite persistent right pressure-overload, increased exercise tolerance and survival, with greater benefits in EarlyEX+MCT. This was accompanied by improvements in the markers of cardiac remodeling (SERCA2a), neurohumoral activation (lower endothelin-1, brain natriuretic peptide and preserved vascular endothelial growth factor mRNA), metabolism and mitochondrial oxidative stress in both exercise interventions. EarlyEX+MCT provided additional improvements in fibrosis, tumor necrosis factor-alpha/interleukin-10 and brain natriuretic peptide mRNA, and beta/alpha myosin heavy chain protein expression. The present study demonstrates important cardioprotective effects of aerobic exercise in experimental PAH, with greater benefits obtained when exercise training is initiated at an early stage of the disease.

  5. Music and Quality of Life in Early-Deafened Late-Implanted Adult Cochlear Implant Users

    NARCIS (Netherlands)

    Fuller, Christina; Mallinckrodt, Lisa; Maat, Bert; Başkent, Deniz; Free, Rolien

    Hypothesis and Background: The early-deafened, late-implanted (EDLI) CI users constitute a relatively new and understudied clinical population. To contribute to a better understanding of the implantation outcome, this study evaluated this population for self-reported enjoyment and perception of

  6. Tactile Sensitivity and Braille Reading in People with Early Blindness and Late Blindness

    Science.gov (United States)

    Oshima, Kensuke; Arai, Tetsuya; Ichihara, Shigeru; Nakano, Yasushi

    2014-01-01

    Introduction: The inability to read quickly can be a disadvantage throughout life. This study focused on the associations of braille reading fluency and individual factors, such as the age at onset of blindness and number of years reading braille, and the tactile sensitivity of people with early and late blindness. The relationship between reading…

  7. Non-targeted plasma metabolome of early and late lactation gilts

    Science.gov (United States)

    Female pigs nursing their first litter (first-parity gilts) have increased energy requirements not only to support their piglets, but they themselves are still maturing. Non-targeted plasma metabolomics were used to investigate the differences between (1) post-farrowing and weaning (early or late l...

  8. Evidence Supporting an Early as Well as Late Heavy Bombardment on the Moon

    Science.gov (United States)

    Frey, Herbert

    2015-01-01

    Evidence supporting an intense early bombardment on the Moon in addition to the traditional Late Heavy Bombardment at approx. 4 BY ago include the distribution of N(50) Crater Retention Ages (CRAs) for candidate basins, a variety of absolute age scenarios for both a "young" and an "old" Nectaris age, and the decreasing contrasts in both topographic relief and Bouguer gravity with increasing CRA.

  9. Mobility in Central European Late Eneolithic and Early Bronze Age: femoral cross-sectional geometry

    Czech Academy of Sciences Publication Activity Database

    Sládek, Vladimír; Berner, M.; Sailer, R.

    2006-01-01

    Roč. 130, č. 3 (2006), s. 320-332 ISSN 0002-9483 R&D Projects: GA ČR GP206/01/D018 Institutional research plan: CEZ:AV0Z60930519 Keywords : biomechanics * mobility * bone strength * Late Eneolithic * Early Bronze Age Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 2.136, year: 2006

  10. The difference in causes of early and late ultrafiltration failure in peritoneal dialysis

    NARCIS (Netherlands)

    Smit, Watske; Parikova, Alena; Struijk, Dirk G.; Krediet, Raymond T.

    2005-01-01

    OBJECTIVE: Ultrafiltration failure (UFF) is a major complication of peritoneal dialysis. Although it seems associated with long-term treatment, it can also occur in recently started patients. To identify the causes of this complication in patients with early and late UFF we studied a group of 48

  11. Effect of ocean gateways on the global ocean circulation in the late Oligocene and early Miocene

    NARCIS (Netherlands)

    von der Heydt, A.S.|info:eu-repo/dai/nl/245567526; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467

    2006-01-01

    We investigate the effect of changes in the tectonic boundary conditions on global ocean circulation patterns. Using a fully coupled climate model in an idealized setup, we compare situations corresponding to the late Oligocene, the early Miocene, and present day. The model results show the

  12. Assembly of fibronectin into the extracellular matrix of early and late passage human skin fibroblasts

    International Nuclear Information System (INIS)

    Mann, D.M.

    1987-01-01

    The specific binding of soluble 125 I-human plasma fibronectin ( 125 I-HFN-P) to confluent cultures of early and late passage human skin fibroblasts was investigated. Previous studies HFN-P bound to fibroblast cell layers indicated that HNF-P was present in the cultures in two separate pools, distinguishable on the basis of their solubility in 1% deoxycholate. Examination of the kinetics of 125 I-HFN-P binding to Pool I of early and late passage cultures revealed that both cultures required 2-4 h to approach steady-state conditions. Other kinetic studies showed that the rates of low of 125 I-HFN-P from either Pool I or Pool II were similar for both cultures. Further, Scatchard analysis revealed a single class of Pool I binding sites with apparent dissociation constants (K/sub d/) of 5.3 x 10 -8 M (early passage) and 4.2 x 10 -8 M (late passage). These results indicate that early and late passage cultures of human fibroblasts exhibit differences in the number of cell surface biding sites for soluble fibronectin, and in the extent to which they incorporate soluble fibronectin into the extracellular matrix. Parameters which affect the fibronectin matrix assembly system of human skin fibroblasts were also examined. In addition, several monoclonal anti-fibronectin antibodies were characterized and developed as experimental probes for fibronectin structure and function

  13. Prognosis of cerebral vein thrombosis presenting as isolated headache: Early vs. late diagnosis

    NARCIS (Netherlands)

    Gameiro, Joana; Ferro, José M.; Canhão, Patricia; Stam, Jan; Barinagarrementeria, Fernando; Lindgren, Arne

    2012-01-01

    Objective: To analyse the outcome of cerebral venous thrombosis (CVT) patients presenting with isolated headache, specifically to compare isolated headache patients with early vs. late CVT diagnosis. Method: In the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) database we

  14. Evaluation of the attentional capacities and working memory of early and late blind persons.

    Science.gov (United States)

    Pigeon, Caroline; Marin-Lamellet, Claude

    2015-02-01

    Although attentional processes and working memory seem to be significantly involved in the daily activities (particularly during navigating) of persons who are blind and who use these abilities to compensate for their lack of vision, few studies have investigated these mechanisms in this population. The aim of this study is to evaluate the selective, sustained and divided attention, attentional inhibition and switching and working memory of blind persons. Early blind, late blind and sighted participants completed neuropsychological tests that were designed or adapted to be achievable in the absence of vision. The results revealed that the early blind participants outperformed the sighted ones in selective, sustained and divided attention and working memory tests, and the late blind participants outperformed the sighted participants in selective, sustained and divided attention. However, no differences were found between the blind groups and the sighted group in the attentional inhibition and switching tests. Furthermore, no differences were found between the early and late blind participants in this set of tests. These results suggest that early and late blind persons can compensate for the lack of vision by an enhancement of the attentional and working memory capacities. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. EFFECTIVENESS AND SAFETY OF INFLIXIMAB IN PATIENTS WITH EARLY AND LATE JUVENILE RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    Е.I. Alexeeva

    2010-01-01

    Full Text Available The article presents results of a study of effectiveness and safety of infliximab — monoclonal antibodies to the tumor necrotizing factor (TNF in treatment of 100 patients11 months — 17 years old with early and late articular types of juvenile rheumatoid arthritis. The duration of treatment was 3 months — 2 years. Infliximap was delivered intravenously by scheme: infusion on 0, 2nd, 6th weeks and then every 8th week. The single dose of infliximab in patients with early rheumatoid arthritis was 6.7 (5.5; 9.0 mg/kg, with late type — 6.0 (5.0; 7.0 mg/kg of body weight. 102 weeks of treatment with anti-TNF-agent provided development of clinical remission, decrease and normalization of laboratory tests of disease’s activity, total restoration of joint’s function, increase of quality of life (on 97% in patients with early type, and 72% 0 in ones with late type. The drug was abolished in 39 (39% of patients, 23% — due to the development of secondary inefficiency, and 11% — due to the development of unfavorable effects.Key words: children, early and late rheumatoid arthritis, treatment, infliximab.(Voprosy sovremennoi pediatrii — Current Pediatrics. – 2010;9(3:30-42

  16. Physical activity patterns in patients with early and late age-related macular degeneration

    DEFF Research Database (Denmark)

    Subhi, Yousif; Sørensen, Torben Lykke

    2016-01-01

    INTRODUCTION: Age-related macular degeneration (AMD) leads to visual impairment that affects visual functioning and thereby the ability to be physically active. We investigated physical activity patterns in patients with AMD. METHODS: Patients with early and late AMD and elderly controls were...

  17. A new record of Equus (Mammalia: Equidae from the Late Pleistocene of central-south Chile Un nuevo registro de Equus (Mammalia: Equidae para el Pleistoceno Superior de Osorno, Chile

    Directory of Open Access Journals (Sweden)

    OMAR P RECABARREN

    2011-12-01

    Full Text Available Fourteen dental and bone parts of a horse excavated from the Pilauco paleontological site, Osorno (40°39' S-73°07' W are analysed and interpreted. This site was formed in association with a peat bog located on the banks of the old Damas River and has conserved abundant late Pleistocene mammalian fauna and flora materials. A date of 11457 ± 140 14C yrs B.P. was obtained from a molar and agrees with our stratigraphic age model. We have identified the fossils as pertaining to the species Equus (Amerhippus andium, which confirms its presence in central-south Chile. Furthermore, the recorded geographic location indicate that the metapodial adaptations of the specimens previously described agree with the reconstructed late Pleistocene landscape of Pilauco, dominated by soft volcanic soils and isolated forest patches over large extensions of grasslands.Se analizan e interpretan 14 fósiles correspondientes a dientes y huesos de caballo registrados en el sitio Pilauco, Osorno (40°39' S-73°07' W. El sitio se formó asociado a un pantano en un borde del antiguo río Damas; en él se ha conservado abundante material de mastofauna y flora pleistocénica. Una fecha radiocarbónica de 11457 ± 140 A.P obtenida de un molar, es concordante con el modelo de edad del sitio. La identificación taxonómica permite asociar a los fósiles a la especie Equus (Amerhippus andium, lo que confirma la presencia de la especie en el centro-sur de Chile. Por otra parte, la posición geográfica de los hallazgos y la reconstrucción del paisaje indicarían que se trata de ejemplares cuyas adaptaciones en los metapodios son concordantes para el paisaje pleistocénico de Pilauco dominado por suelos volcánicos blandos, con presencia de bosquetes dispersos en grandes extensiones de praderas de gramíneas.

  18. Skin manifestations in sulfur mustard exposed victims with ophthalmologic complications: Association between early and late phase

    Directory of Open Access Journals (Sweden)

    Somayeh Hejazi, MD

    Full Text Available Context: Sulfur mustard (SM was used during the Iraq-Iran war (1980–1988. Exposed veterans continue to suffer from its ocular, skin, and respiratory complications. Objective: We aimed to evaluate associations between early (at the time of acute exposure and decades later skin manifestations in individuals with severe ophthalmologic complications secondary to sulfur mustard exposure. Materials and methods: One hundred forty-nine veterans with severe ocular injuries were evaluated for acute and chronic skin complications. Logistic regression models were used to examine the associations between early and late skin manifestations. Results: Late skin complaints were observed in nearly all survivors who had early skin lesions (131 out of 137; 95.62%. Seven out of 12 patients (58.33% who did not have early skin lesions ultimately developed late skin complications. There was a significant relationship between the presence of lesions at the time of exposure and developing late skin complaints (two-sided Fisher's exact test, OR = 15.59, p < 0.001. There was an association between having at least one early skin lesion and occurrence of late skin complications. Survivors with blisters at the time of chemical exposure were more likely to complain of itching (95% CI: 3.63–25.97, p < 0.001, burning (OR = 11.16; 95% CI: 2.97–41.89, p < 0.001, pigmentation changes (OR = 10.17; 95% CI: 2.54–40.75, p = 0.001, dryness (OR = 6.71, 95% CI: 1.22–37.01, p = 0.03 or cherry angioma (OR = 2.59; 95% CI:1.21–5.55, p = 0.01 during the late phase. Using multivariate logistic models, early blisters remained significantly associated with latent skin complaints. Of note, the genitalia and great flexure areas were the most involved anatomical sites for both early and late skin lesions in SM exposed survivors. Conclusion: According to this study, the presence of blisters at the time of exposure to SM is the most important predictor of developing

  19. Pleistocene and Holocene Iberian flora: a complete picture and review

    Science.gov (United States)

    González Sampériz, Penélope

    2010-05-01

    A detailed analysis of the location and composition of Iberian vegetation types during the whole Pleistocene and Holocene periods shows a complex patched landscape with persistence of different types of ecosystems, even during glacial times. In addition, recent, high-resolution palaeoecological records are changing the traditional picture of post-glacial vegetation succession in the Iberian Peninsula. The main available charcoal and pollen sequences include, coniferous and deciduous forest, steppes, shrublands, savannahs and glacial refugia during the Pleistocene for Meso-thermophytes (phytodiversity reservoirs), in different proportions. This panorama suggests an environmental complexity that relates biotic responses to climate changes forced by Milankovitch cycles, suborbital forcings and by the latitudinal and physiographic particularities of the Iberian Peninsula. Thus, many factors are critical in the course of vegetational developments and strong regional differences are observed since the Early Pleistocene. Currently, the flora of Iberia is located in two biogeographical/climatic regions: the Eurosiberian and the Mediterranean. The first one includes northern and northwestern areas of the peninsula, where post-glacial responses of vegetation are very similar to Central Europe, although with some particularities due to its proximity to both the Atlantic Ocean and the Mediterranean region. The second one comprises the main territory of Iberia and shows more complex patterns and singularities, now and in the past. Steppe landscapes dominated extensive areas over all the territory during the cold spells of the Quaternary, especially during the Late Pleistocene up to the Last Glacial Maximum, but differences in composition of the dominant taxa (Compositae versus Artemisia) are observed since the Early Pleistocene, probably related to moisture regional gradients. Coastal shelves and intramountainous valleys, even in continental areas, are spots of floristic

  20. Late- versus early-onset geriatric depression in a memory research center

    Directory of Open Access Journals (Sweden)

    Carol Dillon

    2009-10-01

    Full Text Available Carol Dillon1, Ricardo F Allegri2, Cecilia M Serrano1, Mónica Iturry1, Pablo Salgado1, Frank B Glaser1, Fernando E Taragano21Memory Research Center, Department of Neurology, Hospital General Abel Zubizarreta, GCBA Buenos Aires, Argentina; 2Department of Neuropsychology (SIREN, CEMIC University, Buenos Aires, ArgentinaObjective: To contrast early-onset (<60 years and late-onset (>60 years depression in geriatric patients by evaluating differences in cognition, vascular comorbidity and sociological risk factors. Both patient groups were compared with normal subjects.Materials and methods: We recruited 76 patients with depressive symptoms (37 late onset and 39 early onset and 17 normal controls matched by age and educational level. All subjects were assessed using a semistructured neuropsychiatric interview and an extensive neuropsychological battery. Vascular and sociological risk factors were also evaluated.Results: We found a significant variation in performance between depressive patients and normal controls in most cognitive functions, especially memory (P < 0.0001, semantic fluency (P < 0.0001, verbal fluency, and digit-symbol (P < 0.0001. Late-onset depression patients scored lower and exhibited more severe impairment in memory domains than early-onset depression patients (P < 0.05. Cholesterol levels and marital status were significantly (P < 0.05 different between the depressive groups. Both depressed groups (early- and lateonset were more inactive than controls (P < 0.05; odds ratio: 6.02.Conclusion: Geriatric depression may be a manifestation of brain degeneration, and the initial symptom of a dementia. It is important to consider this in the treatment of patients that exhibit late-onset depressive symptoms.Keywords: early- and late-onset depression, geriatrics, cognition

  1. Dissociating early- and late-selection processes in recall: the mixed blessing of categorized study lists.

    Science.gov (United States)

    Guzel, Mehmet A; Higham, Philip A

    2013-07-01

    Two experiments are reported in which we used type-2 signal detection theory to separate the effects of semantic categorization on early- and late-selection processes in free and cued recall. In Experiment 1, participants studied cue-target pairs for which the targets belonged to two, six, or 24 semantic categories, and later the participants were required to recall the targets either with (cued recall) or without (free recall) the studied cues. A confidence rating and a report decision were also required, so that we could compute both forced-report quantity and metacognitive resolution (type-2 discrimination), which served as our estimates of early- and late-selection processes, respectively. Consistent with prior research, having fewer categories enhanced the early-selection process (in performance, two > six > 24 categories). However, in contrast, the late-selection process was impaired (24 > six = two categories). In Experiment 2, encoding of paired associates, for which the targets belonged to either two or 20 semantic categories, was manipulated by having participants either form interactive images or engage in rote repetition. Having fewer categories again was associated with enhanced early selection (two > 20 categories); this effect was greater for rote repetition than for interactive imagery, and greater for free recall than for cued recall. However, late selection again showed the opposite pattern (20 > two categories), even with interactive-imagery encoding, which formed distinctive, individuated memory traces. The results are discussed in terms of early- and late-selection processes in retrieval, as well as overt versus covert recognition.

  2. Early Versus Late Weight-Bearing Protocols for Surgically Managed Posterior Wall Acetabular Fractures.

    Science.gov (United States)

    Heare, Austin; Kramer, Nicholas; Salib, Christopher; Mauffrey, Cyril

    2017-07-01

    Despite overall improved outcomes with open reduction and internal fixation of acetabular fractures, posterior wall fractures show disproportionately poor results. The effect of weight bearing on outcomes of fracture management has been investigated in many lower extremity fractures, but evidence-based recommendations in posterior wall acetabular fractures are lacking. The authors systematically reviewed the current literature to determine if a difference in outcome exists between early and late postoperative weight-bearing protocols for surgically managed posterior wall acetabular fractures. PubMed and MEDLINE were searched for posterior wall acetabular fracture studies that included weight-bearing protocols and Merle d'Aubigné functional scores. Twelve studies were identified. Each study was classified as either early or late weight bearing. Early weight bearing was defined as full, unrestricted weight bearing at or before 12 weeks postoperatively. Late weight bearing was defined as restricted weight bearing for greater than 12 weeks postoperatively. The 2 categories were then compared by functional score using a 2-tailed t test and by complication rate using chi-square analysis. Six studies (152 fractures) were placed in the early weight-bearing category. Six studies (302 fractures) were placed in the late weight-bearing category. No significant difference in Merle d'Aubigné functional scores was found between the 2 groups. No difference was found regarding heterotopic ossification, avascular necrosis, superficial infections, total infections, or osteoarthritis. This systematic review found no difference in functional outcome scores or complication rates between early and late weight-bearing protocols for surgically treated posterior wall fractures. [Orthopedics. 2017: 40(4):e652-e657.]. Copyright 2017, SLACK Incorporated.

  3. The cheetah Acinonyx pardinensis (Croizet et Jobert, 1828) s.l. at the hominin site of Dmanisi (Georgia) - A potential prime meat supplier in Early Pleistocene ecosystems

    Science.gov (United States)

    Hemmer, Helmut; Kahlke, Ralf-Dietrich; Vekua, Abesalom K.

    2011-09-01

    The fossil site of Dmanisi (southern Georgia) has yielded a significant amount of hominin remains dated to around 1.8 Ma, in addition to a rich contemporaneous faunal record. Based on topographic information combined with an updated list of the vertebrate faunal assemblage, the corresponding palaeo-landscape has been reconstructed. Over a distance of some kilometres the landscape pattern changed from that of a forested valley floor, to tree savannah and open grasslands, thus providing typical habitats for carnivores hunting in open spaces. Morphological analysis of the elements from a nearly complete cat's foreleg reveals the existence of a large and stoutly built cheetah, Acinonyx pardinensis (Croizet et Jobert, 1828) s.l., in the Dmanisi faunal assemblage. Body mass estimations based on the humerus and metacarpals point to a cat of around 100 kg. The amount of pure meat and associated leftovers produced by the cheetah's hunting activity available for other consumers has been estimated. Within Early Pleistocene ecosystems, the cheetah must be considered as a potential fresh prime meat supplier, above that of any other felid.

  4. Effects of Group Prenatal Care on Food Insecurity during Late Pregnancy and Early Postpartum.

    Science.gov (United States)

    Heberlein, Emily C; Frongillo, Edward A; Picklesimer, Amy H; Covington-Kolb, Sarah

    2016-05-01

    This study compared the effects of group to individual prenatal care in late pregnancy and early postpartum on (1) women's food security and (2) psychosocial outcomes among food-insecure women. We recruited 248 racially diverse, low-income, pregnant women receiving CenteringPregnancy™ group prenatal care (N = 124) or individual prenatal care (N = 124) to complete surveys in early pregnancy, late pregnancy, and early postpartum, with 84 % completing three surveys. Twenty-six percent of group and 31 % of individual care participants reported food insecurity in early pregnancy (p = 0.493). In multiple logistic regression models, women choosing group versus individual care were more likely to report food security in late pregnancy (0.85 vs. 0.66 average predicted probability, p care average predicted probability, p care average predicted probability, p = 0.052) in intention-to-treat models. Group participants were more likely to change perceptions on affording healthy foods and stretching food resources. Group compared to individual care participants with early pregnancy food insecurity demonstrated higher maternal-infant attachment scale scores (89.8 vs. 86.2 points for individual care, p = 0.032). Group prenatal care provides health education and the opportunity for women to share experiences and knowledge, which may improve food security through increasing confidence and skills in managing household food resources. Health sector interventions can complement food assistance programs in addressing food insecurity during pregnancy.

  5. Reversible defects on myocardial perfusion imaging early after coronary stent implantation: a predictor of late restenosis

    International Nuclear Information System (INIS)

    Kim, D. E.; Park, S. A.; Kim, C. K.; Chang, J. A.; Jeong, J. W.; Oh, S. G.; Lee, C.

    2007-01-01

    It appears logical that myocardial perfusion should be fixed and not reversible, in the territory supplied by a dilated coronary artery. However, several studies have demonstrated reversible perfusion in the territory supplied by a coronary artery with an optimally implanted stent. The main objective of this study was to evaluate the incidence of reversible defects detected by M-SPECT early after optimal PTCA with stent implantation. Its second objective was to determine the predictive value of detecting reversible defects after stent implantation for late restenosis. Sixty-six patients that underwent M-SPECT within 24 hours of successful PTCA with stent implantation were included. All patients were followed up clinically and angiographically. The incidence of reversible perfusion defects on M-SPECT and the rate of late restenosis in target coronary arteries were evaluated retrospectively. Reversible perfusion defects on M-SPECT were observed in 26% of the patients and in 36% of lesions following successful PTCA with stent implantation. The incidence of late restenosis was significantly higher in patients and lesions with reversible perfusion defects (47% vs. 18%). According to binary logistic regression analysis, the presence of a reversible perfusion defects was the only independent predictor of late restenosis. This study shows that the predictive value of reversible perfusion defects on M-SPECT early after stent implantation with respect to the incidence of late restenosis was 47% in patients with a reversible defect, and 18% in those without it

  6. Orbital- to Sub-Orbital-Scale Cyclicity in Seismic Reflections and Sediment Character in Early to Middle Pleistocene Mudstone, Santa Barbara Basin, California

    Science.gov (United States)

    Peterson, C. D.; Behl, R. J.; Nicholson, C.; Lisiecki, L. E.; Sorlien, C. C.

    2009-12-01

    High-resolution seismic reflection records and well logs from the Santa Barbara Channel suggest that large parts of the Pleistocene succession records climate variability on orbital to sub-orbital scales with remarkable sensitivity, much like the well-studied sediments of the last glacial cycle (ODP Site 893). Spectral analysis of seismic reflection data and gamma ray logs from stratigraphically similar Pleistocene sections finds similar cyclic character and shifts through the section. This correlation suggests that acoustic impedance and physical properties of sediment are linked by basin-scale, likely climatically-driven, oscillations in lithologic composition and fabric during deposition, and that seismic profiling can provide a method for remote identification and correlation of orbital- and sub-orbital-scale sedimentary cyclicity. Where it crops out along the northern shelf of the central Santa Barbara Channel, the early to middle Pleistocene succession (~1.8-1.2 Ma) is a bathyal hemipelagic mudstone with remarkably rhythmic planar bedding, finely laminated fabric, and well-preserved foraminifera, none of which have been significantly altered, or obscured by post-depositional diagenesis or tectonic deformation. Unlike the coarser, turbiditic successions in the central Ventura and Los Angeles basins, this sequence has the potential to record Quaternary global climate change at high resolution. Seismic reflection data (towed chirp) collected on the R/V Melville 2008 Cruise (MV08) penetrate 10's of meters below seafloor into a ~1 km-long sequence of south-dipping seismic reflectors. Sampling parallel to the seafloor permits acquisition of consistent signal amplitude for similar reflectors without spreading loss. Based on established age ranges for this section, sedimentation rates may range from 0.4 to 1.4 meters/kyr, therefore suggesting that the most powerful cycles are orbital- to sub-orbital-scale. Discrete sets of cycles with high power show an abrupt shift

  7. Late Paleogene-early Neogene dinoflagellate cyst biostratigraphy of the eastern Equatorial Atlantic

    Science.gov (United States)

    Awad, Walaa K.; Oboh-Ikuenobe, Francisca E.

    2018-04-01

    Six dinoflagellate cyst biozones (zone 1-zone 5, subzones 1a and 1b) are recognized in the late Paleogene-early Neogene interval of the Ocean Drilling Program (ODP) Site 959 (Hole 959 A), Côte d'Ivoire-Ghana Transform Margin in the eastern Equatorial Atlantic. The biozones are based on palynological analysis of 30 samples covering a 273.2-m interval with generally fair preservation and good to poor recovery. We propose a new age of Late Eocene (Priabonian) for subunit IIB as opposed to the previously published mid-Early Oligocene age (middle Rupelian). This age assignment is mainly based on the presence of Late Eocene marker taxa, such as Hemiplacophora semilunifera and Schematophora speciosa in the lower part of the studied interval. We also document for the first time a hiatus event within dinoflagellate cyst zone 3, based on the last occurrences of several taxa. This interval is assigned to an Early Miocene age and is barren of other microfossils. Furthermore, we propose new last occurrences for two species. The last occurrence of Cerebrocysta bartonensis is observed in the late Aquitanian-early Burdigalian in this study vs. Priabonian-early Rupelian in mid and high latitude regions. Also, the last occurrence of Chiropteridium galea extends to the latest Early Miocene (Burdigalian) in ODP Hole 959 A; this event was previously identified in other studies as Chattian in equatorial regions, and Aquitanian in the Northern Hemisphere mid-latitudes. We suspect that these differences are due to physical (offshore vs. nearshore) and latitudinal locations of the areas studied.

  8. 1300 km long late Pleistocene-Holocene shelf edge barrier reef system along the western continental shelf of India: Occurrence and significance

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Wagle, B.G.; Veerayya, M.; Almeida, F.; Karisiddaiah, S.M.

    . It is surmised that coral/algal reef growth commenced with the advent of the Holocene trangression and favorable antecedent topography, and continued until early Holocene. Subsequently, rapid sea level rise drowned the reefs. The shelf edge reefs, therefore...

  9. Gender differences in nutritional behavior and weight status during early and late adolescence.

    Science.gov (United States)

    Askovic, Branka; Kirchengast, Sylvia

    2012-07-01

    The current study aimed to determine gender differences in nutritional habits, eating behaviour, weight status, body image and weight control practices during early and late adolescence. 677 Viennese pupils (253 boys and 424 girls) between the ages 10 and 18 years (x = 14.1 yrs; +/- 2.2) were enrolled in the study. Weight status was determined by means of body mass index percentiles. To assess eating behavior, food preferences, body image and weight control practices, a 48 item questionnaire was developed. Significant gender differences in weight status were observable during late adolescence only. Girls are significantly less satisfied with their body weight. Furthermore, girls practice dieting and weight control to avoid any weight gain more frequently than boys. Gender differences in eating behavior intensified from early to late adolescence. From early to late adolescence, meal size decreased among girls, while it remains stabile or increased among boys. Boys eat generally more than girls. Furthermore, boys preferred meat and fast food while girls consumed fruits, vegetables and healthy food significantly more frequently. These gender differences are explained by gender specific energetic demands and culture typical beauty ideals.

  10. Differential effects of estradiol on carotid artery inflammation when administered early versus late after surgical menopause.

    Science.gov (United States)

    Sophonsritsuk, Areepan; Appt, Susan E; Clarkson, Thomas B; Shively, Carol A; Espeland, Mark A; Register, Thomas C

    2013-05-01

    The aim of this study was to determine the effects of estrogen therapy (ET) on carotid artery inflammation when initiated early and late relative to surgical menopause. Female cynomolgus macaques consuming atherogenic diets were ovariectomized and randomized to control or oral estradiol (E2; human equivalent dose of 1 mg/d micronized E2) initiated at 1 month (early menopause, n = 24) or 54 months (late menopause, n = 40) after ovariectomy. The treatment period was 8 months. Carotid artery expression of the markers of monocyte/macrophages (CD68 and CD163), dendritic cells (CD83), natural killer cells (neural cell adhesion molecule-1), and interferon-γ was significantly lower in E2-treated animals in the early menopause group but not in the late menopause group (P menopausal stage (P menopause inhibits macrophage accumulation in the carotid artery, an effect that is not observed when E2 is administered after several years of estrogen deficiency. No evidence for pro-inflammatory effects of late ET is observed. The results provide support for the timing hypothesis of postmenopausal ET with implications for the interpretation of outcomes in the Women's Health Initiative.

  11. Early vs late orthodontic treatment of deepbite: a prospective clinical trial in growing subjects.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Giuntini, Veronica; Masucci, Caterina; Vangelisti, Andrea; Defraia, Efisio

    2012-07-01

    The aim of this prospective clinical trial was to compare the outcomes of prepubertal vs pubertal treatment of deepbite patients with a protocol including biteplane and fixed appliances. A sample of 58 subjects with deepbite completed the study. A total of 34 subjects received treatment with removable biteplane appliances in the mixed dentition at a prepubertal stage of skeletal maturation (early treatment group), and 24 subjects were treated at a pubertal stage of skeletal maturation in the permanent dentition (late treatment group). All subjects of both groups were reevaluated after an average period of 15 months after the completion of fixed appliance therapy. Treatment outcomes were assessed statistically after a phase with removable biteplane appliances and at the posttreatment observation. Treatment duration was significantly shorter in the early treatment group than in the late treatment group. Overbite reduction was significantly greater in the late treatment group (-3.1 mm) than in the early treatment group (-1.4 mm). In the late treatment group, 92% of the patients had a corrected overbite 1 year after therapy. Treatment of deepbite at puberty in the permanent dentition leads to significantly more favorable outcomes than treatment before puberty in the mixed dentition. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  12. Running economy in early and late maturing youth soccer players does not differ.

    Science.gov (United States)

    Segers, V; De Clercq, D; Janssens, M; Bourgois, J; Philippaerts, R

    2008-04-01

    The aim of this study was to investigate the influence of maturity on running economy in a population of young soccer players. 13 boys (mean age 14.3 years) active in soccer were divided into two groups: 6 early and 7 late maturers. Anthropometrical characteristics, respiratory exchange ratio, heart rate and maximal oxygen uptake were measured. Running economy was assessed at three submaximal running speeds (8, 9.5 and 11 km/h). Allometric coefficients were calculated and used to diminish the effect of body mass. In addition, running style was analysed biomechanically (stride length and meaningful kinematic values). There was no significant difference in the running economy of early and late maturing soccer players, nor any significant differences in mass adjusted physiological values. Therefore physiological differences cannot explain why late maturers succeed in keeping up with early maturers. Late maturing boys take longer relative strides, and have more anteversion of the thigh at heel contact, a smaller knee-angle during swing-phase and a lower mass moment of inertia. Running style seems to be an important determinant in running economy of children.

  13. ASSESSMENT OF OXIDATIVE STRESS IN EARLY AND LATE ONSET PRE-ECLAMPSIA AMONG GHANAIAN WOMEN.

    Science.gov (United States)

    Tetteh, P W; Adu-Bonsaffoh, K; Antwi-Boasiako, C; Antwi, D A; Gyan, B; Obed, S A

    2015-01-01

    Pre-eclampsia is a multisystem pregnancy-related disorder with multiple theories regarding its aetiology resulting in lack of reliable screening tests and well-established measures for primary prevention. However, oxidative stress is increasingly being implicated in the pathogenesi of pre-eclampsia although conflicting findings have been reported. To determine and compare the levels of oxidative stress in early and late onset pre-eclampsia by measuring urinary excretion of isoprostane and total antioxidant power (TAP) in a cohort of pre-eclamptic women at Korle Bu Teaching Hospital. This was a cross-sectional study conducted at Korle-Bu Teaching Hospital, Accra, Ghana involving pre-eclamptic women between the ages 18 and 45 years who gave written informed consent. Urinary isoprostane levels were determined using an enzyme-linked immunosorbent assay (ELISA) kit whereas the Total Anti-oxidant Power in urine samples was determined using Total Antioxidant Power Colorimetric Microplate Assay kit. The data obtained were analyzed using MEGASTAT statistical software package. We included 102 pre-eclamptic women comprising 68 (66.7%) and 34 (33.3%) with early-onset and late-onset pre-eclampsia respectively. There were no statistically significant differences between the mean maternal age, haematological indices, serum ALT, AST, ALT, albumin, urea, creatinine uric acid and total protein at the time of diagnosis. The mean gestational age at diagnosis of early and late onset pre-eclampsia were 31.65 ± 0.41 and 38.03 ± 0.21 respectively (p ˂ 0.001). Also, there were statistically significant differences between the diastolic blood pressure (BP), systolic BP and mean arterial pressure (MAP) at diagnosis of pre-eclampsia in the two categories. The mean urinary Isoprostane excretion was significantly higher in the early onset pre-eclamptic group (3.04 ± 0.34 ng/mg Cr) compared to that of the late onset pre-eclamptic group (2.36 ± 0.45 ng/mg Cr), (p=0.019). Urinary total

  14. A comparative study of frontal bone morphology among Pleistocene hominin fossil groups.

    Science.gov (United States)

    Athreya, Sheela

    2009-12-01

    Features of the frontal bone that are conventionally used to distinguish among fossil hominin groups were quantitatively examined. Fifty-five fossil crania dating from the early to the late Pleistocene were analyzed. Using a modified pantograph, outlines of the frontal bone were collected along the midsagittal and two parasagittal planes. The profile from nasion to bregma, as well as two profiles above the medial and lateral sections of the orbit, respectively, extending from the orbital margin to the coronal suture were traced. The outlines were measured using Elliptical Fourier Function Analysis (EFFA), which enabled a quantification of aspects of the frontal bone that have historically been described primarily in nonmetric or linear terms. Four measurements were obtained: 1) overall morphology as expressed in the Fourier harmonic amplitudes; 2) maximum projection of the supraorbital torus at three points along the browridge (glabella and the medial and lateral aspects of the torus above the orbit); 3) maximum distance of the frontal squama from the frontal chord, capturing forehead curvature; and 4) nasion-bregma chord length. The results indicate that the midsagittal profile is significantly different among all Pleistocene groups in analyses that include both size and shape, as well as size-adjusted data. Homo erectus is significantly different from the late Pleistocene groups (Neandertals and early modern H. sapiens) in glabellar projection. Anatomically modern humans are significantly different from all other groups in both raw and size-standardized analyses of all three outlines that captured overall morphology, as well as forehead curvature and lateral supraorbital torus prominence, and middle Pleistocene Homo are significantly different in both medial and lateral overall parasagittal form. However, for the majority of analyses there were no significant differences among the Pleistocene archaic groups in supraorbital torus projection, frontal squama

  15. LA-ICP-MS and SIMS U-Pb and U-Th zircon geochronological data of Late Pleistocene lava domes of the Ciomadul Volcanic Dome Complex (Eastern Carpathians

    Directory of Open Access Journals (Sweden)

    Réka Lukács

    2018-06-01

    Full Text Available This article provides laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS and secondary ionization mass spectrometry (SIMS U-Pb and U-Th zircon dates for crystals separated from Late Pleistocene dacitic lava dome rocks of the Ciomadul Volcanic Dome Complex (Eastern Carpathians, Romania. The analyses were performed on unpolished zircon prism faces (termed rim analyses and on crystal interiors exposed through mechanical grinding an polishing (interior analyses. 206Pb/238U ages are corrected for Th-disequilibrium based on published and calculated distribution coefficients for U and Th using average whole-rock and individually analyzed zircon compositions. The data presented in this article were used for the Th-disequilibrium correction of (U-Th/He zircon geochronology data in the research article entitled “The onset of the volcanism in the Ciomadul Volcanic Dome Complex (Eastern Carpathians: eruption chronology and magma type variation” (Molnár et al., 2018 [1].

  16. Liver CT for vascular mapping during radioembolisation workup : comparison of an early and late arterial phase protocol

    NARCIS (Netherlands)

    van den Hoven, Andor F; Braat, Manon N G J A; Prince, Jip F; van Doormaal, Pieter J; van Leeuwen, Maarten S; Lam, Marnix G E H; van den Bosch, Maurice A A J

    OBJECTIVES: To compare right gastric (RGA) and segment 4 artery (A4) origin detection rates during radioembolisation workup between early and late arterial phase liver CT protocols. METHODS: 100 consecutive patients who underwent liver CT between May 2012-January 2015 with early or late arterial

  17. Pleistocene lake level changes in Western Mongolia

    Science.gov (United States)

    Borodavko, P. S.

    2009-04-01

    Global cooling in the Early Pleistocene caused extensive continental glaciation in the northern hemisphere including the arid areas of Central Asia. The reduction of temperatures (particularly summer temperatures) reduced evaporation and strengthened the importance of precipitation. The simultaneity of "lakes periods" (pluvials) and stages of glaciation is established experience confirmed by investigations in the west of North America and Russia. In the Mongolian Great Lakes Depression new evidence for similar conditions is found. The Great Lakes Depression is one of the largest in Central Asia, and is divided into 2 main Lakes basins: Hyargas Lake Basin and Uvs Lake Basin. The basin is 600-650 km in length with a width of 200-250 km in the north and 60-100 km in the south. Total catchment area is about 186600 km2. The elevation of the basin floor is from 1700 m a.s.l. to 760 m a.s.l., decreasing to the north and south-east. The depression extends south-north and is bounded by mountains: Tannu-Ola to the north, Hangai to the east; Gobi Altai to the south and Mongolian Altay to the west. The maximum elevation of the mountains is 4000 m a.s.l. There are some mountains with an elevation between 2000 and 3000 m a.s.l in the lake catchment. These mountains are not glaciated today. The geological record [1] suggests the Great Lakes Depression already existed in the Mesozoic, but assumed its modern form only during the Pliocene-Quaternary when tectonic movements caused the uplift of the surrounding mountains. A phase of tectonic stability occurred during the Late Quaternary. The depression is filled by Quaternary fluvial, aeolian and lacustrine deposits (e.g. sand, pebbles). The Neogene deposits are represented by coloured clay, marl, sand and sandstone [1]. Hyargas Lake is the end base level of erosion of the lake group consisting of the Hara-Us Nur, Dorgon, Hara Nur and Airag lakes. Hyargas is one of the largest lakes in Mongolia, with a water surface of 1,407 km2. The

  18. Early and late fracture following extensive limb lengthening in patients with achondroplasia and hypochondroplasia.

    Science.gov (United States)

    Kitoh, H; Mishima, K; Matsushita, M; Nishida, Y; Ishiguro, N

    2014-09-01

    Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The Mann‑Whitney U test and Pearson's chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened

  19. Possible Late Pleistocene volcanic activity on Nightingale Island, South Atlantic Ocean, based on geoelectrical resistivity measurements, sediment corings and 14C dating

    DEFF Research Database (Denmark)

    Bjørk, Anders Anker; Björck, Svante; Cronholm, Anders

    2011-01-01

    . The irregular shapes of the basins and the lack of clear erosional features indicate that they are not eruption craters and were not formed by erosion. Instead, we regard them as morphological depressions formed between ridges of trachytic lava flows and domes at a late stage of the formation of the volcanic...... edifice. The onset of sedimentation within these basins appears to have occurred between 24 and 37 ka with the highest situated wetland yielding the highest ages. These ages are very young compared to the timing of the main phase of the formation of the island, implying volcanic activity on the island......Tristan da Cunha is a volcanic island group situated in the central South Atlantic. The oldest of these islands, Nightingale Island, has an age of about 18Ma. In the interior of the island, there are several wetlands situated in topographic depressions. The ages of these basins have been unknown...

  20. Early and late humoral rejection: a clinicopathologic entity in two times.

    Science.gov (United States)

    Péfaur, J; Díaz, P; Panace, R; Salinas, P; Fiabane, A; Quinteros, N; Chea, R; Naranjo, E; Wurgaft, A; Beltran, E; Elgueta, S; Wegmann, M E; Gajardo, J G; Contreras, L

    2008-11-01

    Humoral rejection is an important cause of early and late graft loss. The late variant is difficult to diagnose and treat. There is a close correlation between sclerosing nephropathy and anti-HLA antibodies. We analyzed 113 renal allograft recipients between August 2004 and April 2007. Acute humoral rejection was defined as acute graft dysfunction in presence of donor-specific antibodies (DSA) detected by flow panel reactive antibodies (PRA) and/or C4d positive pericapilary tubules (PTC) detected histopathologically by immunofluorescent or immunoperoxidase at less than 3 months postransplantation. Late humoral rejection was defined as dysfunction occurring after 3 months postransplantation with histopathologic glomerulopathy or vasculopathy and positive C4d PTC. We included all patients who were diagnosed with early or late graft dysfunction and underwent biopsy, all of which were examined for C4d. Four patients had acute humoral rejection treated with IVIG or plasmapheresis. The patient and graft survivals were 100% and serum creatinine averaged 1.7 mg/dL. Three recipients experienced late humoral rejection at 3 to 10 years posttransplantation All received high-dose IVIG; one also was treated with thymoglobulin. Immunosuppression was switched to tacrolimus, mycophenolate mofetil, and steroids. Only one patient recovered renal function; the others returned to dialysis. Among seven patients only one had an actual PRA (>20%) and three showed 10% to 20%. However, six had a positive historical PRA of 10% to 50%. In conclusion, Recognition of acute humoral rejection has contributed to graft rescue by controlling alloantibody production through new specific immunosuppressive therapies in contrast with the clinical response to acute therapy, treatment of a chronic entity has shown poor outcomes, probably because antibody mediated chronic graft damage is already present when the late diagnosis is established by biopsy.

  1. 2014 CODEPEH recommendations: Early detection of late onset deafness, audiological diagnosis, hearing aid fitting and early intervention.

    Science.gov (United States)

    Núñez-Batalla, Faustino; Jáudenes-Casaubón, Carmen; Sequí-Canet, Jose Miguel; Vivanco-Allende, Ana; Zubicaray-Ugarteche, Jose

    2016-01-01

    The latest scientific literature considers early diagnosis of deafness as the key element to define the educational and inclusive prognosis of the deaf child, because it allows taking advantage of the critical period of development (0-4 years). Highly significant differences exist between deaf people who have been stimulated early and those who have received late or improper intervention. Early identification of late-onset disorders requires special attention and knowledge on the part of every childcare professional. Programs and additional actions beyond neonatal screening should be designed and planed to ensure that every child with a significant hearing loss is detected early. For this purpose, the CODEPEH would like to highlight the need for continuous monitoring of children's auditory health. Consequently, CODEPEH has drafted the recommendations included in the present document. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  2. Prognosis of late versus early ventricular fibrillation in acute myocardial infarction

    DEFF Research Database (Denmark)

    Jensen, G V; Torp-Pedersen, C; Køber, L

    1990-01-01

    VF was not associated with heart failure. When VF was associated with heart failure (secondary VF) early VF had a greater mortality than late VF after 2 and 5 years. Logistic regression analysis showed that heart failure (relative risk 1.9 [1.1 to 3.1]) and cardiogenic shock (relative risk 3.9 [1.......8 to 8.5]) were significant risk factors for in-hospital death. Late VF compared to early VF had no prognostic implication (relative risk 1.0 [0.6 to 1.6]). For patients discharged from the hospital, risk factors were heart failure (1.8 [1.1 to 2.8]) and previous AMI (1.6 [1.3 to 2.1]).(ABSTRACT...... TRUNCATED AT 250 WORDS)...

  3. Differences in diagnostic subtypes among patients with late and early onset of a single depressive episode

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel

    2006-01-01

    OBJECTIVE: It is unclear whether patients with late onset and patients with early onset present with different subtypes of depression. The aim of the study was to compare the prevalence of subtypes of ICD-10 single depressive episodes for patients with late onset (age >65 years) and patient...... with early onset (age single depressive episode in a period from 1994-2002 at the end of the first outpatient treatment or at the first discharge from...... psychiatric hospitalisation ever in Denmark were identified in a nationwide register. RESULTS: In total, 18.192 patients were given a diagnosis of a single depressive episode at the first outpatient contact and 8.396 patients were given a diagnosis of a single depressive episode at the first psychiatric...

  4. Proposed UK high-latitude rocket campaign in late 1976/early 1977

    International Nuclear Information System (INIS)

    Thomas, G.R.; Bryant, D.A.

    1975-01-01

    The second major UK high-latitude rocket campaign is scheduled for late 1976/early 19777 at Andoya. The proposed experiments provide a comprehensive set of measurements of high-latitude phenomena and include studies of the sources and acceleration of auroral particles, the stability of plasma flow, wave-particle interactions, and the response of the atmosphere and ionosphere to enhanced geomagnetic activity. These experiments require co-ordinated launching of high-latitude (740-950 km) and small, medium-altitude (320-370km) rockets. The provisional campaign plan includes four Skylark 12's (with Skylark 11 as a possible substitute), one Skylark 7 (with Skylark 6 as a possible substitute), and five Fulmars (with Skylark 10A as a possible substitute). Some of the experiments require simultaneous measurements by GEOS in the European sector (early 1977), but the remainder could be carried out in late 1976

  5. Enhanced musical rhythmic perception in Turkish early and late learners of German

    Directory of Open Access Journals (Sweden)

    Maria Paula eRoncaglia-Denissen

    2013-09-01

    Full Text Available As language rhythm relies partly on general acoustic properties, such as intensity and duration, mastering two languages with distinct rhythmic properties (i.e., stress position may enhance musical rhythm perception. We investigated whether second language (L2 competence affects musical rhythm aptitude in Turkish early (TELG and late learners (TLLG of German in comparison to German monolingual speakers (GMC. To account for inter-individual differences, we measured participants’ short-term and working memory capacity, melodic aptitude, and time they spent listening to music. Both L2 speaker groups perceived rhythmic variations significantly better than monolinguals. No differences were found between early and late learners’ performances. Our findings suggest that mastering two languages with different rhythmic properties enhances musical rhythm perception, providing further evidence of cognitive share between language and music.

  6. Palaeobotanical data for climate change during the late Miocene - early Pliocene in Western Bulgaria

    International Nuclear Information System (INIS)

    Hristova, Viktoria; Ivanov, Dimiter; Bozukov, Vladimir

    2015-01-01

    The Coexistence Approach (CA) analysis was applied to plant macro- and microfossils from the Late Miocene to Early Pliocene sites in western Bulgaria to obtain quantitative climate data and reconstruct climate dynamics. Calculated new values for the Sofia macro flora confirmed a warm-temperate and humid climate with mean annual temperature (MAT) between 12–170C, mean temperature of the warmest month (WMT) 23.6–280C, mean temperature of the coldest month (CMT) 0–50C and mean annual precipitation (MAP) 843–1179 mm. This is consistent with the climatic parameters obtained from the microflora – MAT 13.6–16, WMT 23.6–27.9, CMT 3.7–6 and MAP 803–1308mm. All presented data are in good accordance with other regional palaeoclimate reconstructions from Bulgarian and Europaean floras. Key words: Late Miocene–Early Pliocene, palaeoclimate, Sofia Basin

  7. Prediction of Late Postoperative Hemorrhage after Whipple Procedure Using Computed Tomography Performed During Early Postoperative Period.

    Science.gov (United States)

    Han, Ga Jin; Kim, Suk; Lee, Nam Kyung; Kim, Chang Won; Seo, Hyeong Il; Kim, Hyun Sung; Kim, Tae Un

    2018-01-01

    Postpancreatectomy hemorrhage (PPH) is an uncommon but serious complication of Whipple surgery. To evaluate the radiologic features associated with late PPH at the first postoperative follow up CT, before bleeding. To evaluate the radiological features associated with late PPH at the first follow-up CT, two radiologists retrospectively reviewed the initial postoperative follow-up CT images of 151 patients, who had undergone Whipple surgery. Twenty patients showed PPH due to vascular problem or anastomotic ulcer. The research compared CT and clinical findings of 20 patients with late PPH and 131 patients without late PPH, including presence of suggestive feature of pancreatic fistula (presence of air at fluid along pancreaticojejunostomy [PJ]), abscess (fluid collection with an enhancing rim or gas), fluid along hepaticojejunostomy or PJ, the density of ascites, and the size of visible gastroduodenal artery (GDA) stump. CT findings including pancreatic fistula, abscess, and large GDA stump were associated with PPH on univariate analysis ( p ≤ 0.009). On multivariate analysis, radiological features suggestive of a pancreatic fistula, abscess, and a GDA stump > 4.45 mm were associated with PPH ( p ≤ 0.031). Early postoperative CT findings including GDA stump size larger than 4.45 mm, fluid collection with an enhancing rim or gas, and air at fluid along PJ, could predict late PPH.

  8. Social change in ‘Phoenicia’ in the late Bronze/early Iron Age transition

    OpenAIRE

    Boyes, Philip

    2013-01-01

    This dissertation explores social, cultural and political changes in the region later known as ‘Phoenicia’ during the period of approximately 1300-900 BC. By applying modern approaches to theoretical questions such as the nature of social change, identity, migration and how such phenomena are represented in the archaeological record, this dissertation aims to provide a discussion of Late Bronze/Early Iron Age Phoenicia based on a more solid methodological foundation than has of...

  9. Episodic and Semantic Autobiographical Memory and Everyday Memory during Late Childhood and Early Adolescence

    OpenAIRE

    Willoughby, Karen A.; Desrocher, Mary; Levine, Brian; Rovet, Joanne F.

    2012-01-01

    Few studies have examined both episodic and semantic autobiographical memory (AM) performance during late childhood and early adolescence. Using the newly developed Children’s Autobiographical Interview (CAI), the present study examined the effects of age and sex on episodic and semantic AM and everyday memory in 182 children and adolescents. Results indicated that episodic and semantic AM both improved between 8 and 16 years of age; however, age-related changes were larger for episodic AM th...

  10. Heart Protection by Combination Therapy with Esmolol and Milrinone at Late-Ischemia and Early Reperfusion

    OpenAIRE

    Huang, Ming-He; Wu, Yewen; Nguyen, Vincent; Rastogi, Saurabh; McConnell, Bradley K.; Wijaya, Cori; Uretsky, Barry F.; Poh, Kian-Keong; Tan, Huay-Cheem; Fujise, Kenichi

    2011-01-01

    Introduction The present study determined whether late-ischemia/early reperfusion therapy with the β1-adrenergic receptor (AR) blocker esmolol and phosphodiesterase III inhibitor milrinone reduced left ventricular (LV) myocardial infarct size (IS). Methods and Results In an ischemia/reperfusion rat model (30-min ischemia/4-hr reperfusion), esmolol, milrinone or esmolol + milrinone were intravenous (IV) infused over 10 min (from the last 5min of ischemia to the first 5min of reperfusion). LV-I...

  11. Evaluation of the attentional capacities and working memory of early and late blind persons

    OpenAIRE

    PIGEON, Caroline; MARIN-LAMELLET, Claude

    2015-01-01

    Although attentional processes and working memory seem to be significantly involved in the daily activities (particularly during navigating) of persons who are blind and who use these abilities to compensate for their lack of vision, few studies have investigated these mechanisms in this population. The aim of this study is to evaluate the selective, sustained and divided attention, attentional inhibition and switching and working memory of blind persons. Early blind, late blind and sighted p...

  12. Late cretaceous to early eocene foraminiferal biostratigraphy of the Rakhi Nala area, Sulaiman Range, Pakistan

    International Nuclear Information System (INIS)

    Afzal, J.

    1996-01-01

    Shaly intervals from late cretaceous to early eocene sediments of the Rakhi Nala Section (Sulaiman Range) were analysed for the foraminiferal micro fauna (Planktons, smaller and larger benthics). The faunal record is interpreted for the precise age and paleo environments. These fresh results, in the light of modern bio stratigraphic knowledge, are compared with the previous bio stratigraphic information available about this area. Several discrepancies regarding the litho and biostratigraphy from the previous literature were addressed and tried to remove. (author)

  13. Geomorphic and sedimentary responses of the Bull Creek Valley (Southern High Plains, USA) to Pleistocene and Holocene environmental change

    Science.gov (United States)

    Arauza, Hanna M.; Simms, Alexander R.; Bement, Leland C.; Carter, Brian J.; Conley, Travis; Woldergauy, Ammanuel; Johnson, William C.; Jaiswal, Priyank

    2016-01-01

    Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.

  14. Different nucleosomal architectures at early and late replicating origins in Saccharomyces cerevisiae.

    Science.gov (United States)

    Soriano, Ignacio; Morafraile, Esther C; Vázquez, Enrique; Antequera, Francisco; Segurado, Mónica

    2014-09-13

    Eukaryotic genomes are replicated during S phase according to a temporal program. Several determinants control the timing of origin firing, including the chromatin environment and epigenetic modifications. However, how chromatin structure influences the timing of the activation of specific origins is still poorly understood. By performing high-resolution analysis of genome-wide nucleosome positioning we have identified different chromatin architectures at early and late replication origins. These different patterns are already established in G1 and are tightly correlated with the organization of adjacent transcription units. Moreover, specific early and late nucleosomal patterns are fixed robustly, even in rpd3 mutants in which histone acetylation and origin timing have been significantly altered. Nevertheless, higher histone acetylation levels correlate with the local modulation of chromatin structure, leading to increased origin accessibility. In addition, we conducted parallel analyses of replication and nucleosome dynamics that revealed that chromatin structure at origins is modulated during origin activation. Our results show that early and late replication origins present distinctive nucleosomal configurations, which are preferentially associated to different genomic regions. Our data also reveal that origin structure is dynamic and can be locally modulated by histone deacetylation, as well as by origin activation. These data offer novel insight into the contribution of chromatin structure to origin selection and firing in budding yeast.

  15. Early elective cesarean delivery before 36 weeks vs late spontaneous delivery in infants with gastroschisis.

    Science.gov (United States)

    Hadidi, Ahmed; Subotic, Ulrike; Goeppl, Maximilian; Waag, Karl-L

    2008-07-01

    The aim of this study is to assess the value of early elective cesarean delivery for patients with gastroschisis in comparison with late spontaneous delivery. Analysis of infants with gastroschisis admitted between 1986 and 2006 at a tertiary care center was performed. The findings were analyzed statistically. Eighty-six patients were involved in the study. This included 15 patients who underwent emergency cesarean delivery (EM CD group) because of fetal distress and/or bowel ischemia. The remaining 71 patients born electively were stratified into 4 groups. The early elective cesarean delivery (ECD) group included 23 patients born by ECD before 36 weeks; late vaginal delivery (LVD) group included 23 patients who had LVD after 36 weeks; 24 patients had LCD after 36 weeks because of delayed diagnosis that resulted in late referral; and 1 patient had early spontaneous vaginal delivery (EVD group) before 36 weeks. The mean time to start oral feeding, incidence of complications, and primary closure were significantly better in the ECD group than in the LVD group. The duration of ventilation and the length of stay were shorter in ECD group, but the difference was not statistically significant. Elective cesarean delivery before 36 weeks allows earlier enteral feeding and is associated with less complications and higher incidence of primary closure (statistically significant).

  16. Colour expectations during object perception are associated with early and late modulations of electrophysiological activity.

    Science.gov (United States)

    Stojanoski, Bobby Boge; Niemeier, Matthias

    2015-10-01

    It is well known that visual expectation and attention modulate object perception. Yet, the mechanisms underlying these top-down influences are not completely understood. Event-related potentials (ERPs) indicate late contributions of expectations to object processing around the P2 or N2. This is true independent of whether people expect objects (vs. no objects) or specific shapes, hence when expectations pertain to complex visual features. However, object perception can also benefit from expecting colour information, which can facilitate figure/ground segregation. Studies on attention to colour show attention-sensitive modulations of the P1, but are limited to simple transient detection paradigms. The aim of the current study was to examine whether expecting simple features (colour information) during challenging object perception tasks produce early or late ERP modulations. We told participants to expect an object defined by predominantly black or white lines that were embedded in random arrays of distractor lines and then asked them to report the object's shape. Performance was better when colour expectations were met. ERPs revealed early and late phases of modulation. An early modulation at the P1/N1 transition arguably reflected earlier stages of object processing. Later modulations, at the P3, could be consistent with decisional processes. These results provide novel insights into feature-specific contributions of visual expectations to object perception.

  17. Differential association with cellular substructures of pseudorabies virus DNA during early and late phases of replication

    International Nuclear Information System (INIS)

    Ben-Porat, T.; Veach, R.A.; Blankenship, M.L.; Kaplan, A.S.

    1984-01-01

    Pseudorabies virus DNA synthesis can be divided into two phases, early and late, which can be distinguished from each other on the basis of the structures of the replicating DNA. The two types of replicating virus DNA can also be distinguished from each other on the basis of the cellular substructures with which each is associated. Analysis by electron microscopic autoradiography showed that during the first round of replication, nascent virus DNA was found in the vicinity of the nuclear membrane; during later rounds of replication the nascent virus DNA was located centrally within the nucleus. The degree of association of virus DNA synthesized at early and late phases with the nuclear matrix fractions also differed; a larger proportion of late than of early nascent virus DNA was associated with this fraction. While nascent cellular DNA only was associated in significant amounts with the nuclear matrix fraction, a large part (up to 40%) of all the virus DNA remained associated with this fraction. However, no retention of specific virus proteins in this fraction was observed. Except for two virus proteins, which were preferentially extracted from the nuclear matrix, approximately 20% of all virus proteins remained in the nuclear matrix fraction. The large proportion of virus DNA associated with the nuclear fraction indicated that virus DNA may be intimately associated with some proteins

  18. Early alcohol use with parental permission: Psychosocial characteristics and drinking in late adolescence.

    Science.gov (United States)

    Colder, Craig R; Shyhalla, Kathleen; Frndak, Seth E

    2018-01-01

    The earliest experiences with alcohol for many children occur in the family context with parental supervision. The current study examined individual and sociocultural characteristics associated with early (prior to age 13years) sipping and tasting alcohol with parental permission in two longitudinal community samples. Early sipping/tasting was also tested as a predictor of frequency and quantity of alcohol use, and alcohol-related problems seven years later in late adolescence. Early sipping/tasting with parental permission was associated with a sociocultural context supportive of alcohol use (e.g., parental alcohol use, permissive rules about alcohol use in the home, parental attitudes about underage drinking, perceived peer norms), adolescent sensation seeking and disinhibition (e.g., surgency, externalizing behavior) and appraisals of alcohol (negative outcome expectancies and negative implicit alcohol associations). Early sipping/tasting predicted increased frequency and quantity of alcohol consumption, and increased alcohol-related problems in late adolescence, even after controlling sociocultural and individual difference variables. Findings suggest that early sipping/tasting with parental permission is not benign and is a viable target for preventive interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A ~600 kyr duration Early Pleistocene record from the West Turkana (Kenya) HSPDP drill site: elemental XRF variability to reconstruct climate change in Turkana Boy's backyard

    Science.gov (United States)

    Stockhecke, M.; Beck, C. C.; Brown, E. T.; Cohen, A.; Deino, A. L.; Feibel, C. S.; Sier, M.

    2015-12-01

    Outcrops in the Kenyan and Ethiopian rift valleys document repeated occurrences of freshwater lakes and wooded landscapes over the past 4 million years at locations that are currently seasonally-dry savanna. Studies of the rich fossil records, in combination with outcropping lacustrine sequences, led to major breakthroughs in our knowledge of driving factors in human evolution. However, study of continuous drill core from ancient lake basins provides a basis for to unravel East African climate dynamics in an unseen fashion. The Hominin Sites and Paleolakes Drilling Project (HSPDP), and the related Olorgesailie Drilling Project, recovered ~2 km of drill core since 2012. A major project goal is characterization of East African paleoclimate in order to evaluate its impact on hominin evolution. XRF core scanning data provide a means of evaluating records of past environmental conditions continuously and at high resolution. However, the HSPDP records contain complex lithologies reflecting repeated episodes of inundation and desiccation of the lake basins. Nevertheless, careful data evaluation based on detailed lithostratigraphy, which includes smear-slide microscopic analyses and X-radiographic images, allows disentanglement of complex signals and robust identification of continuous sequences for any cyclostratigraphic and statistical analysis. At the HSPDP Turkana Basin site a 175.6 m-long core the covers the Early Pleistocene time window during which hominids first expanded out of Africa and marine records document reorganization of tropical climate and the development of the strong Walker circulation. This drill site carries particular interest as it is located in only 2.5 km from the location of one of the most complete hominin skeletons ever recovered (Turkana Boy). Here we present a methodological approach to address the highly variable lithostratigraphy of the East African records to establish comprehensive and environmentally meaningful paleoclimate timeseries

  20. Oxygen and silicon stable isotopes of diatom silica. Reconstructing changes in surface water hydrography and silicic acid utilization in the late Pleistocene subarctic Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Edith

    2014-03-05

    Deglacial variations in upper ocean nutrient dynamics and stratification in high latitudes, as well as associated changes in thermohaline overturning circulation, are thought to have played a key role in changing atmospheric CO{sub 2} concentrations. This thesis examines the relationship between past changes in subarctic Pacific upper ocean stratification and nutrient (silicic acid) utilization, using oxygen and silicon stable isotopes of diatom silica, for the first time at millennial-scale resolution and analyzed with a new and efficient instrumentation set-up. The isotopic data, presented in three manuscripts, show a consistent picture of millennial-scale variability in upper ocean stratification and silicic acid utilization during the last ∝50 ka BP, e.g. indicating that the subarctic Pacific was a source region for atmospheric CO{sub 2} during the last deglaciation (late Heinrich Stadial 1 and the Boelling/Alleroed). The presented results demonstrate the high potential of combined diatom oxygen and silicon stable isotope analysis especially for, but not restricted to, marine regions characterized by a low biogenic carbonate content like the subarctic Pacific and the Southern Ocean.

  1. Oxygen and silicon stable isotopes of diatom silica. Reconstructing changes in surface water hydrography and silicic acid utilization in the late Pleistocene subarctic Pacific

    International Nuclear Information System (INIS)

    Maier, Edith

    2014-01-01

    Deglacial variations in upper ocean nutrient dynamics and stratification in high latitudes, as well as associated changes in thermohaline overturning circulation, are thought to have played a key role in changing atmospheric CO 2 concentrations. This thesis examines the relationship between past changes in subarctic Pacific upper ocean stratification and nutrient (silicic acid) utilization, using oxygen and silicon stable isotopes of diatom silica, for the first time at millennial-scale resolution and analyzed with a new and efficient instrumentation set-up. The isotopic data, presented in three manuscripts, show a consistent picture of millennial-scale variability in upper ocean stratification and silicic acid utilization during the last ∝50 ka BP, e.g. indicating that the subarctic Pacific was a source region for atmospheric CO 2 during the last deglaciation (late Heinrich Stadial 1 and the Boelling/Alleroed). The presented results demonstrate the high potential of combined diatom oxygen and silicon stable isotope analysis especially for, but not restricted to, marine regions characterized by a low biogenic carbonate content like the subarctic Pacific and the Southern Ocean.

  2. No surface breaking on the Ecemiş Fault, central Turkey, since Late Pleistocene (~ 64.5 ka); new geomorphic and geochronologic data from cosmogenic dating of offset alluvial fans

    Science.gov (United States)

    Sarıkaya, M. A.; Yıldırım, C.; Çiner, A.

    2015-05-01

    The Ecemiş Fault Zone (EF) has been recognized as a major left lateral strike-slip fault in the Central Anatolian Fault Zone (CAFZ) of Turkey. However, its Quaternary slip-rate has been challenging to determine due to the difficulty of dating offset markers. Using high-precision offset measurements and 36Cl cosmogenic nuclide dating, we present the first geochronologically determined Late Quaternary slip-rate for the EF. Our study focuses on the excellent exposures of offset alluvial fan surfaces, originating from the Aladağlar, a Late Quaternary glaciated mountain. Analysis of airborne orthophotogrametry and GNSS (Global Navigation Satellite System) surveys indicates 168 ± 2 m left lateral and 31 ± 1 m vertical displacements. In-situ terrestrial cosmogenic 36Cl geochronology obtained from eleven surface boulders provides a minimum abandonment/incision age of 104.2 ± 16.5 ka for the oldest offset alluvial fan surface. Our geomorphic observations together with Self-potential geophysical surveys revealed the presence of an unfaulted alluvial fan terrace, which allows us to constrain the timing of deformation. The abandonment/incision age of this fan is 64.5 ± 5.6 ka based on thirteen 36Cl depth profile samples. Accordingly, we obtained a geologic fault slip-rate of 4.2 ± 1.9 mm a- 1 horizontally and 0.8 ± 0.3 mm a- 1 vertically for the time frame between 104.2 ± 16.5 ka and 64.5 ± 5.6 ka. Our analysis indicates that the EF has not been producing a major surface breaking earthquake on the main strand at least since 64.5 ± 5.6 ka (mid-Late Pleistocene). This could be the result of abandonment of the main strand and accommodation of deformation by other faults within the EF. Nevertheless, a recently occurred (30 September 2011) low magnitude (ML: 4.3) left lateral strike-slip earthquake indicates recent seismic activity of the EF. Comparison of the recent GPS velocity field with the longer slip history along the CAFZ indicates a constant but low strain

  3. A new Late Ordovician erratic anthaspidellid sponge (Porifera) originating from Baltica

    NARCIS (Netherlands)

    Rhebergen, F.

    2014-01-01

    The new anthaspidellid taxon Brevaspidella dispersa is erected for specimens recovered from the Late Ordovician sponge assemblages of the island of Gotland, Sweden and the Dutch-German border region. In the latter area, they are collected from Early Pleistocene fluvial deposits of the Baltic River

  4. Microfaunal analysis of late Quaternary deposits of the northern Bering Sea.

    Science.gov (United States)

    McDougall, K.

    1982-01-01

    Holocene microfaunal associations and distribution patterns define three inner-shelf (1-20m) biofacies in Norton Sound, northern Bering Sea. The Holocene facies relations are the basis for interpreting early Holocene and late Pleistocene environmental conditions in the NE Bering Sea area. Norton Sound cores provide evidence of two marine transgressions and a varying river input.-from Author

  5. Late Pliocene/Pleistocene changes in Arctic sea-ice cover: Biomarker and dinoflagellate records from Fram Strait/Yermak Plateau (ODP Sites 911 and 912)

    Science.gov (United States)

    Stein, Ruediger; Fahl, Kirsten; Matthiessen, Jens

    2014-05-01

    have been important for general cooling and ice-sheet build-up. (4) Maxima in sea ice occurred near 3.3, 2.7, 2.1, 1.7 and during the last 1.2 Ma whereas between about 2.6 and 2.2 Ma the sea-ice cover was surprisingly reduced. The IP25 maxima are similar to those determined for the late Holocene. (5) Both, dinoflagellate and IP25/PIP25 data indicate that also during the Late Pliocene Warming Event at least occasionally sea ice must have occurred. (6) This low-resolution pilot study motivates to carry out further detailed high-resolution sea-ice biomarker research on ODP/IODP material in order to prove or disprove these preliminary interpretations. References Belt, S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of palaeo sea ice: IP25. Organic Geochemistry 38, 16-27. Müller, J., Wagner, A., Fahl, K., Stein, R., Prange, M., Lohmann, G., 2011. Towards quantitative sea ice reconstructions in the northern North Atlantic: A combined biomarker and numerical modelling approach. Earth Planetary Science Letters 306, 137-148.

  6. Quantification of climate and vegetation from southern African Middle Stone Age sites - an application using Late Pleistocene plant material from Sibudu, South Africa

    Science.gov (United States)

    Bruch, Angela A.; Sievers, Christine; Wadley, Lyn

    2012-06-01

    In southern Africa numerous Middle Stone Age (MSA) sites document important steps in technological and behavioural development leading to significant changes in the lifeways of modern humans. To assess whether these cultural changes and developments may be related to environmental changes we need to ascertain past environments. To do this we apply a new quantitative method, the GIS-based Coexistence Approach (CAGIS), on fossil plant material from the MSA site Sibudu, KwaZulu-Natal, South Africa. Previous qualitative environmental interpretations of the fossil fauna and flora of the site remain ambiguous. Because much of the material is anthropogenically introduced, it is difficult to distinguish between the effects of natural changes in the local vegetation and behavioural changes of the people that inhabited the shelter. CAGIS can be applied to such biased assemblages and seems to be an adequate method to directly quantify palaeoclimate and vegetation parameters at an archaeological site. The CAGIS analysis shows that during the Howiesons Poort (HP) Industry winters were slightly colder and drier than present, whereas during summer, temperatures and precipitation were similar to today. Post-HP winters were drier and colder than present, presumably colder than during the HP. Summer temperatures remained the same, but summer precipitation decreased from the HP to post-HP. Vegetation cover was less than today, may be even less than during the HP. The late MSA was observably warmer than the older periods, especially during winter. At the same time summer precipitation slightly increased and vegetation became more dense, but still remained generally open similar to today's anthropogenic landscape. Generally, climatic changes are most pronouncedly reflected in winter temperature parameters, especially in minimum winter temperatures, and to a lesser extent by changes in summer precipitation. The observed ecological trends seem to be affected mainly by variations through

  7. Interaction between aggrading geomorphic surfaces and the formation of a late pleistocene paleosol in the palouse loess of eastern Washington state

    Science.gov (United States)

    McDonald, Eric V.; Busacca, Alan J.

    1990-09-01

    Variable rates of loess deposition contributed to dramatic regional variation in a soil-stratigraphic unit, the Washtucna Soil, in the Palouse loess deposits in the Channeled Scabland of eastern Washington state. Throughout most of the Channeled Scabland, the morphology of the Washtucna Soil is that of a single buried soil, but it bifurcates into two well-developed and pedologically distinct buried soils in areas immediately downwind of the major source of loessial sediment. Regional loess stratigraphy confirms that the two well-developed soils formed during the same interval of time during which only one soil formed in areas that are distal to loess source areas. The variable and perhaps rapid rates of soil formation suggested by the stratigraphy resulted from an interaction between variable rates of loess deposition and the formation of superimposed calcic soils. Petrocalcic horizons with weak Stage IV morphology formed as the zone of carbonate accumulation moved up into former A and cambic horizons that had been profusely burrowed by cicadas. The development of cicada burrows in one phase of soil development that were subsequently engulfed by pedogenic carbonate under a rising land surface seems to have greatly accelerated the development of the petrocalcic horizons. Accelerated rates of formation of the petrocalcic horizons occurred when extrinsic (pulses of loess deposition) and intrinsic (engulfment of burrowed horizons) thresholds were exceeded. Stratigraphic evidence suggests that the soil formation that accompanied the rise in the land surface due to additional loess deposition may have occurred during the late Wisconsin glaciation when giant glacial outburst floods in the channeled Scabland triggered a new cycle of loess deposition.

  8. Factors associated with preterm, early preterm and late preterm birth in Malawi.

    Directory of Open Access Journals (Sweden)

    Nynke R van den Broek

    Full Text Available Assessment of risk factors for preterm birth in a population with high incidence of preterm birth and HIV infection.Secondary analysis of data for 2,149 women included in a community based randomized placebo controlled trial for the prevention of preterm birth (APPLe trial (ISRCTN84023116 with gestational age at birth determined through ultrasound measurement in early pregnancy. Multivariate Logistic Regression analyses to obtain models for three outcome variables: all preterm, early preterm, and late preterm birth.No statistical differences were noted for the prevalence of HIV infection (p = 0.30 or syphilis (p = 0.12 between women who delivered preterm versus term. BMI (Adjusted OR 0.91 (0.85-0.97; p = 0.005 and weight gain (Adjusted OR 0.89 (0.82-0.97; p = 0.006 had an independent, protective effect. Previous preterm birth doubled the odds of preterm birth (Adjusted OR 2.13 (1.198-3.80; p = 0.01. Persistent malaria (despite malaria prophylaxis increased the risk of late preterm birth (Adjusted OR 1.99 (1.05-3.79; p = 0.04. Age <20 (Adjusted OR 1.73 (1.03-2.90; p = 0.04 and anemia (Adjusted OR 1.95 (1.08-3.52; p = 0.03 were associated with early preterm birth (<34 weeks.Despite claims that HIV infection is an important cause of preterm birth in Africa, we found no evidence of an association in this population (unexposed to anti-retroviral treatment. Persistent malaria was associated with late preterm birth. Maternal undernourishment and anemia were independently associated with early preterm birth. The study did not assess whether the link was direct or whether a common precursor such as chronic infection was responsible for both maternal effects and early labour.

  9. The Stochastic Early Reaction, Inhibition, and late Action (SERIA model for antisaccades.

    Directory of Open Access Journals (Sweden)

    Eduardo A Aponte

    2017-08-01

    Full Text Available The antisaccade task is a classic paradigm used to study the voluntary control of eye movements. It requires participants to suppress a reactive eye movement to a visual target and to concurrently initiate a saccade in the opposite direction. Although several models have been proposed to explain error rates and reaction times in this task, no formal model comparison has yet been performed. Here, we describe a Bayesian modeling approach to the antisaccade task that allows us to formally compare different models on the basis of their evidence. First, we provide a formal likelihood function of actions (pro- and antisaccades and reaction times based on previously published models. Second, we introduce the Stochastic Early Reaction, Inhibition, and late Action model (SERIA, a novel model postulating two different mechanisms that interact in the antisaccade task: an early GO/NO-GO race decision process and a late GO/GO decision process. Third, we apply these models to a data set from an experiment with three mixed blocks of pro- and antisaccade trials. Bayesian model comparison demonstrates that the SERIA model explains the data better than competing models that do not incorporate a late decision process. Moreover, we show that the early decision process postulated by the SERIA model is, to a large extent, insensitive to the cue presented in a single trial. Finally, we use parameter estimates to demonstrate that changes in reaction time and error rate due to the probability of a trial type (pro- or antisaccade are best explained by faster or slower inhibition and the probability of generating late voluntary prosaccades.

  10. Abrogation of Early Apoptosis Does Not Alter Late Inhibition of Hippocampal Neurogenesis After Irradiation

    International Nuclear Information System (INIS)

    Li Yuqing; Aubert, Isabelle; Wong, C. Shun

    2010-01-01

    Purpose: Irradiation of the adult brain results in acute apoptosis of neural progenitors and vascular endothelial cells, as well as late dysfunction of neural progenitors and inhibition of neurogenesis. We sought to determine whether the early apoptotic response has a causative role in late inhibition of neurogenesis after cranial irradiation. Methods and Materials: Using a genetic approach with p53 and smpd1 transgenic mice and a pharmacologic approach with basic fibroblast growth factor (bFGF) to abrogate the early apoptotic response, we evaluated the late inhibition of neurogenesis in the hippocampal dentate gyrus after cranial irradiation. Results: In dentate gyrus, subgranular neural progenitors underwent p53-dependent apoptosis within 24 h after irradiation. Despite a near abrogation of neural progenitor apoptosis in p53-/- mice, the reduction in newborn neurons in dentate gyrus at 9 weeks after irradiation in p53-/- mice was not different from that observed in wildtype controls. Endothelial cell apoptosis after radiation is mediated by membrane damage initiated by activation of acid sphingomyelinase (ASMase). Deletion of the smpd1 gene (which encodes ASMase) attenuated the apoptotic response of endothelial cells. At 9 weeks after irradiation, the inhibition of hippocampal neurogenesis was not rescued by ASMase deficiency. Intravenous administration of bFGF protected both endothelial cells and neural progenitors against radiation-induced apoptosis. There was no protection against inhibition of neurogenesis at 9 weeks after irradiation in bFGF-treated mice. Conclusion: Early apoptotic death of neural progenitors, endothelial cells, or both does not have a causative association with late inhibition of neurogenesis after irradiation.

  11. Semantic and syntactic reading comprehension strategies used by deaf children with early and late cochlear implantation.

    Science.gov (United States)

    Gallego, Carlos; Martín-Aragoneses, M Teresa; López-Higes, Ramón; Pisón, Guzmán

    2016-01-01

    Deaf students have traditionally exhibited reading comprehension difficulties. In recent years, these comprehension problems have been partially offset through cochlear implantation (CI), and the subsequent improvement in spoken language skills. However, the use of cochlear implants has not managed to fully bridge the gap in language and reading between normally hearing (NH) and deaf children, as its efficacy depends on variables such as the age at implant. This study compared the reading comprehension of sentences in 19 children who received a cochlear implant before 24 months of age (early-CI) and 19 who received it after 24 months (late-CI) with a control group of 19 NH children. The task involved completing sentences in which the last word had been omitted. To complete each sentence children had to choose a word from among several alternatives that included one syntactic and two semantic foils in addition to the target word. The results showed that deaf children with late-CI performed this task significantly worse than NH children, while those with early-CI exhibited no significant differences with NH children, except under more demanding processing conditions (long sentences with infrequent target words). Further, the error analysis revealed a preference of deaf students with early-CI for selecting the syntactic foil over a semantic one, which suggests that they draw upon syntactic cues during sentence processing in the same way as NH children do. In contrast, deaf children with late-CI do not appear to use a syntactic strategy, but neither a semantic strategy based on the use of key words, as the literature suggests. Rather, the numerous errors of both kinds that the late-CI group made seem to indicate an inconsistent and erratic response when faced with a lack of comprehension. These findings are discussed in relation to differences in receptive vocabulary and short-term memory and their implications for sentence reading comprehension. Copyright © 2015

  12. Meal frequencies in early adolescence predict meal frequencies in late adolescence and early adulthood

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Flachs, Esben Meulengracht

    2013-01-01

    Health and risk behaviours tend to be maintained from adolescence into adulthood. There is little knowledge on whether meal frequencies in adolescence are maintained into adulthood. We investigated whether breakfast, lunch and evening meal frequencies in early adolescence predicted meal frequencies...

  13. Early versus late tracheostomy in pediatric intensive care unit: does it matter? A 6-year experience.

    Science.gov (United States)

    Pizza, Alessandro; Picconi, Enzo; Piastra, Marco; Genovese, Orazio; Biasucci, Daniele G; Conti, Giorgio

    2017-08-01

    The aim of this study is to examine the clinical data of children who underwent tracheostomy during their stay in Pediatric Intensive Care Unit (PICU), in order to describe the relationship between the timing of tracheostomy, the length of PICU stay and the occurrence of ventilator-associated pneumonia (VAP). This is a retrospective cohort study that collects all patients undergoing tracheostomy during their PICU stay over a six-year period. Data collection included PICU length of stay, days of intubation, days of mechanical ventilation, primary indication for tracheostomy, information about VAP and decannulations. The early tracheostomy group was defined as patients who had ten or fewer days of continuous ventilation, whereas the late tracheostomy group had more than ten days of continuous ventilation. A significant decrease in the rate of VAP incidence was noticed in the early tracheostomy group vs. late group (P=0.004, OR=0.39, 95% CI: 0.18-0.85). No differences were observed about decannulation, need of long-term ventilation and death rate. Significant decreases of days of mechanical ventilation and PICU stay were found in subgroup of patients who underwent early tracheostomy and were decannulated within 18 months. No standard timing for tracheostomy placement has been established in the pediatric population. Early tracheostomy can shorten the days of ventilation and hospitalization in PICU and reduce the incidence of VAP, but further studies are needed to identify patient categories in which it can be of benefit.

  14. Hippidion saldiasi Roth, 1899 (Mammalia, Perissodactyla en el Pleistoceno tardío de Calama, norte de Chile Late Pleistocene Hippidion saldiasi Roth, 1899 (Mammalia, Perissodactyla from Calama, northern Chile

    Directory of Open Access Journals (Sweden)

    MARÍA TERESA ALBERDI

    2007-06-01

    Full Text Available Se describen restos del género Hippidion procedentes de la zona del desierto de Atacama (Calama, Segunda Región de Chile. El conjunto analizado corresponde a un esqueleto bastante completo proveniente del yacimiento Betecsa 1, así como escasas unidades del yacimiento Kamac Mayu. En ambos sitios se identifica H. saldiasi. A partir de dos dataciones radiométricas por AMS del ejemplar estudiado, los restos se sitúan estratigráficamente en el Pleistoceno Superior (21.070 ± 100 AP y 21.380 ± 100 14C AP. Se infieren datos ambientales y de dieta a partir de análisis de isótopos estables en los restos de Hippidion saldiasi del sitio Betecsa 1 cuyo valor de δ13C en hueso fue de -15,45 y el valor en esmalte de dientes fue de -16,68, sugiriendo una alimentación con pastos C3. El cráneo recuperado es el primero conocido de esta especieThis paper describes the Hippidion bones recovered from the Atacama Desert (Calama, Second Region of Chile. The analyzed assemblage corresponds to a nearly complete skeleton from Betecsa 1 site and more poorly preserved remains from Kamac Mayu site. In both H. saldiasi is identified. Two 14C radiometric determinations indicate late Pleistocene age for these remains (21,070 ± 100 BP and 21,380 ± 100 BP. Environmental and diet inferences from stable isotope analysis are also presented. The δ13C value from Betecsa 1 horses (-15.45 from bone sample and -16.68 from enamel sample suggest a dietary adaptation exclusively C3 feeders. This is the first skull and associated skeleton recovered of this species

  15. The Balitx landslide (Mallorca, Spain) and its possible seismic origin: active spreading since the Late Pleistocene; El deslizamiento de Balitx (Mallorca) y su posible origen sismico. Procesos activos desde el Pleistoceno superior

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, R. M.; Rodriguez-Peces, M. J.; Azanon, J. M.; Rodriguez-Fernandez, J.; Roldan, F. J.; Garcia-Moreno, I.; Galabert, B.; Garcia-Mayordomo, J.

    2013-02-01

    The Balitx landslide, located on the steep coastal side of the Tramuntana range on the island of Mallorca, is a large translational rock landslide in which the failure surface coincides with the reactivation of an earlier normal fault. The dating of calcite striae on the fault plane with U/Th techniques reveals that the last movement was over 400 kyr ago, which falls outside of the range of this method. The volume of the landslide is estimated to be over 700 million cubic metres, with a north-westward displacement of 300 m. Active extensional cracks as well as block spreads have been identified along the main scarp, together with displacement and toppling of blocks, the beginning of which coincides with oxygen isotope stage OIS 5a (Late Pleistocene = 83 kyr), a wetter and warmer period than the present. Currently active decametre-long cracks up to 50 m wide can be seen to affect the displaced materials. They reveal the rupture of the displaced block into several units at different speeds. A retrospective analysis of slope stability has been carried out, taking into account different scenarios according to three critical sea stands. All the scenarios are stable, with a safety factor of over 1.35. These results support the thesis that the Balitx landslide could have been triggered by seismicity. A study of the Balitx landslide under dynamic conditions reveals that the landslide could have been triggered by a moderate-to-high-magnitude earthquake (Mw=6.0) located close to the landslide (10-30 km) and probably related to some of the active faults identified in Majorca, such as the Palma Fault. (Author) 58 refs.

  16. Earlier Snowmelt Changes the Ratio Between Early and Late Season Forest Productivity

    Science.gov (United States)

    Knowles, J. F.; Molotch, N. P.; Trujillo, E.; Litvak, M. E.

    2017-12-01

    Future projections of declining snowpack and increasing potential evaporation associated with climate warming are predicted to advance the timing of snowmelt in mountain ecosystems globally. This scenario has direct implications for snowmelt-driven forest productivity, but the net effect of temporally shifting moisture dynamics is unknown with respect to the annual carbon balance. Accordingly, this study uses both satellite- and tower-based observations to document the forest productivity response to snowpack and potential evaporation variability between 1989 and 2012 throughout the southern Rocky Mountain ecoregion, USA. These results show that a combination of low snow accumulation and record high potential evaporation in 2012 resulted in the 34-year minimum ecosystem productivity that could be indicative of future conditions. Moreover, early and late season productivity were significantly and inversely related, suggesting that future shifts toward earlier or reduced snowmelt could increase late-season moisture stress to vegetation and thus restrict productivity despite a longer growing season. This relationship was further subject to modification by summer precipitation, and the controls on the early/late season productivity ratio are explored within the context of ecosystem carbon storage in the future. Any perturbation to the carbon cycle at this scale represents a potential feedback to climate change since snow-covered forests represent an important global carbon sink.

  17. Influence Of Feminine Hormones On Some Biochemical Parameters In Early And Late Menopausal Status

    International Nuclear Information System (INIS)

    KAMAL, A.M.

    2009-01-01

    Forty two healthy Egyptian women were participated in this study to evaluate the effect of early and late menopause on some biochemical and hormonal parameters. The women were divided into three equal groups. The first was the pre-menopausal group with regular menstrual cycle, the second was the late menopausal group comprised the menopausal female less than 5 years and the third group consisted of women that became menopause since 5-9 years. The second and third groups had almost the same age and body weight. After clinical examination, fasting blood samples were collected from all volunteers. Regarding the pre-menopausal women, blood was withdrawn between the 3 rd and the 5 th day post-menstruation (follicular phase). Follicle stimulating hormone (FSH), leutinizing hormone (LH), progesterone, prolactin (PRL), testosterone, leptin and thyroxine (T4) in addition to hemoglobin (Hb), blood glucose, calcium (Ca), inorganic phosphorous (P), magnesium (Mg) and uric acid were determined. Both menopausal groups showed significant increase in FSH and LH and significant decrease in PRL and late menopausal group experienced also multiple significant correlations between FSH, LH and other tested parameters. Prolongation of menopause exhibited decrease in leptin being significant as compared to pre-menopausal women than that experienced menopause at younger age. Due to the relation between leptin hormone and osteoporosis, the results of this investigation denoted that early cessation of annulations (menopause) in Egyptian women may lead to disturbance in bone metabolism causing inhibiting osteoblastogenesis and decreasing bone mass.

  18. Characterization of Early and Late Adopters of ATM Card in Indian Banking Industry

    Directory of Open Access Journals (Sweden)

    Kamalpreet Kaur

    2012-11-01

    Full Text Available Normal 0 false false false IN X-NONE AR-SA MicrosoftInternetExplorer4 The present study deals with affect of adoption pattern of the ATMs by banks on its characteristics. With the exploration of various characteristics of the banks like Size, Profi tability, Efficiency, Cost of Operations, Asset quality and Credit risk, Financing Pattern, Diversifi cation and Age etc.; the study has tried to differentiate between the early and late adopter category of the banks regarding ATM cards. The banks have been categorized into early and late adopters on the basis of their adoption period. For this purpose, 50 scheduled commercial banks consisting of 27 Public Sector Banks and 23 Private Sector Banks have been taken as sample to investigate the various aspects of and early adopter banks in comparison to late adopter banks. The time period of the study is 20 years i.e. from 1991 to 2010. It can be concluded that the initiators and fi rst movers take advantage over the late adopters and laggards. They have found to perform better in terms of various parameters. Overall, the early adopter banks are larger in size, more diversifi ed, having lesser branches, more market share and wide ATM network as compared to late adopter ones. Thus, the empirical results evidently reveal that the both the groups have their own different characteristics. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso

  19. Impact of Early Versus Late Diuretic Exposure on Metabolic Bone Disease and Growth in Premature Neonates.

    Science.gov (United States)

    Orth, Lucas E; O'Mara, Keliana L

    2018-01-01

    This study aimed to determine whether there are differences in the incidence of metabolic bone disease (MBD) between preterm neonates first exposed to diuretics prior to 2 weeks of life versus those exposed after 2 weeks. This study was a retrospective analysis of premature neonates born at a tertiary care center between 2011 and 2015 who received either furosemide or chlorothiazide. The primary outcome was incidence of MBD. Secondary outcomes included growth, electrolyte disturbances, oxygen requirement, and length of stay. A total of 147 patients were included. Early initiation (n = 90) and late initiation (n = 57) arms were balanced with respect to birth weight and gestational age. There was no difference in incidence of MBD in the early group (76%) versus the late group (65%; p = 0.164). Stratification by cumulative dose showed incidence of 85% in patients receiving ≥8 mg/kg of furosemide, compared with 68% and 64% of those in the <4 mg/kg and 4 to 7.9 mg/kg strata, respectively (p = 0.06). The early group experienced greater reductions in length-for-age growth during diuretic therapy (-70% versus -40%; p = 0.009). Electrolyte abnormalities were more prevalent in the early group. Although there was no difference in duration of mechanical ventilation, duration of supplemental oxygen requirement was reduced in the late group (75 versus 89 days; p = 0.003). Timing of diuretic initiation did not affect incidence of MBD. Increased cumulative furosemide exposure may be associated with higher incidence. Patients first exposed to diuretics within 2 weeks of life are at higher risk for electrolyte abnormalities and reduced growth velocity.

  20. Classification of Rhinoentomophthoromycosis into Atypical, Early, Intermediate, and Late Disease: A Proposal.

    Directory of Open Access Journals (Sweden)

    Christian G Blumentrath

    Full Text Available Rhinoentomophthoromycosis, or rhino-facial conidiobolomycosis, is a rare, grossly disfiguring disease due to an infection with entomophthoralean fungi. We report a case of rhinoentomophthoromycosis from Gabon and suggest a staging system, which provides information on the prognosis and duration of antifungal therapy.We present a case of rhinoentomophthoromycosis including the histopathology, mycology, and course of disease. For the suggested staging system, all cases on confirmed rhinoentomophthoromycosis published in the literature without language restriction were eligible. Exclusion criteria were missing data on (i duration of disease before correct diagnosis, (ii outcome, and (iii confirmation of entomophthoralean fungus infection by histopathology and/or mycology. We classified cases into atypical (orbital cellulitis, severe pain, fever, dissemination, early, intermediate, and late disease based on the duration of symptoms before diagnosis. The outcome was evaluated for each stage of disease.The literature search of the Medpilot database was conducted on January 13, 2014, (updated on January 18, 2015. The search yielded 8,333 results including 198 cases from 117 papers; of these, 145 met our inclusion criteria and were included in the final analysis. Median duration of treatment was 4, 3, 4, and 5 months in atypical, early, intermediate, and late disease, respectively. Cure rates were clearly associated with stage of disease and were 57%, 100%, 82%, and 43% in atypical, early, intermediate, and late disease, respectively.We suggest a clinical staging system that underlines the benefit of early case detection and may guide the duration of antifungal treatment. The scientific value of this classification is its capacity to structure and harmonize the clinical and research approach towards rhinoentomophthoromycosis.

  1. The Pleistocene rivers of the English Channel region

    Science.gov (United States)

    Antoine, Pierre; Coutard, Jean-Pierre; Gibbard, Philip; Hallegouet, Bernard; Lautridou, Jean-Pierre; Ozouf, Jean-Claude

    2003-02-01

    The Pleistocene history of river systems that enter the English Channel from northern France and southern England is reviewed. During periods of low sea-level (cold stages) these streams were tributaries of the Channel River. In southern England the largest, the River Solent, is an axial stream that has drained the Hampshire Basin from the Early Pleistocene or late Pliocene. Other streams of southern England may be of similar antiquity but their records are generally short and their sedimentary history have been destroyed, as in northern Brittany, by coastal erosion and valley deepening as a consequence of tectonic uplift. In northern France, the Seine and Somme rivers have very well developed terrace systems recording incision that began at around 1 Ma. The uplift rate, deduced from the study of these terrace systems, is of 55 to 60 m myr-1 since the end of the Early Pleistocene. Generally the facies and sedimentary structures indicate that the bulk of the deposits in these rivers accumulated in braided river environments under periglacial climates in all the area around the Channel. Evolution of the rivers reflects their responses to climatic change, local geological structure and long-term tectonic activity. In this context the Middle Somme valley is characterised by a regular pattern in which incision occurs at the beginning of each glacial period within a general background of uplift. Nevertheless the response of the different rivers to climatic variations, uplift and sea-level changes is complex and variable according to the different parts of the river courses.

  2. Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

    Directory of Open Access Journals (Sweden)

    Goździk Jan

    2017-06-01

    Full Text Available Deposits formed between the Neogene/Pleistocene transition and into the Early Pleistocene have been studied, mainly on the basis of drillings and at rare, small outcrops in the lowland part of Polish territory. At the Bełchatów lignite mine (Kleszczów Graben, central Poland, one of the largest opencast pits in Europe, strata of this age have long been exposed in extensive outcrops. The present paper is based on our field studies and laboratory analyses, as well as on research data presented by other authors. For that reason, it can be seen as an overview of current knowledge of lowermost Pleistocene deposits at Bełchatów, where exploitation of the Quaternary overburden has just been completed. The results of cartographic work, sedimentological, mineralogical and palynological analyses as well as assessment of sand grain morphology have been considered. All of these studies have allowed the distinction of three Lower Pleistocene series, i.e., the Łękińsko, Faustynów and Krzaki series. These were laid down in fluvial environments between the end of the Pliocene up to the advance of the first Scandina