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https://www.readbyqxmd.com/read/28820899/two-disjunct-pleistocene-populations-and-anisotropic-postglacial-expansion-shaped-the-current-genetic-structure-of-the-relict-plant-amborella-trichopoda
#1
Rémi Tournebize, Stéphanie Manel, Yves Vigouroux, François Munoz, Alexandre de Kochko, Valérie Poncet
Past climate fluctuations shaped the population dynamics of organisms in space and time, and have impacted their present intra-specific genetic structure. Demo-genetic modelling allows inferring the way past demographic and migration dynamics have determined this structure. Amborella trichopoda is an emblematic relict plant endemic to New Caledonia, widely distributed in the understory of non-ultramafic rainforests. We assessed the influence of the last glacial climates on the demographic history and the paleo-distribution of 12 Amborella populations covering the whole current distribution...
2017: PloS One
https://www.readbyqxmd.com/read/28811644/the-link-between-enso-like-forcing-and-hydroclimate-variability-of-coastal-east-asia-during-the-last-millennium
#2
Jungjae Park, Jiwoo Han, Qiuhong Jin, Junbeom Bahk, Sangheon Yi
Inconsistent reconstructions of East Asian hydroclimate for the last millennium significantly limit our understanding of the mechanisms behind climate variability during the medieval climate anomaly (MCA) and little ice age (LIA) in the region. In this study, we present new high-resolution multiproxy records (diatom, δ(13)C, C/N, TS) from the Mulyoungari swamp, Jeju Island, South Korea. Our results indicate that El Niño southern oscillation-like variations caused the dry MCA/wet LIA pattern in the study area...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28811519/high-resolution-mapping-based-on-an-unmanned-aerial-vehicle-uav-to-capture-paleoseismic-offsets-along-the-altyn-tagh-fault-china
#3
Mingxing Gao, Xiwei Xu, Yann Klinger, Jerome van der Woerd, Paul Tapponnier
The recent dramatic increase in millimeter- to centimeter- resolution topographic datasets obtained via multi-view photogrammetry raises the possibility of mapping detailed offset geomorphology and constraining the spatial characteristics of active faults. Here, for the first time, we applied this new method to acquire high-resolution imagery and generate topographic data along the Altyn Tagh fault, which is located in a remote high elevation area and shows preserved ancient earthquake surface ruptures. A digital elevation model (DEM) with a resolution of 0...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28780964/the-contexts-and-early-acheulean-archaeology-of-the-ef-hr-paleo-landscape-olduvai-gorge-tanzania
#4
Ignacio de la Torre, Rosa M Albert, Richard Macphail, Lindsay J McHenry, Michael C Pante, Ágata Rodríguez-Cintas, Ian G Stanistreet, Harald Stollhofen
Renewed fieldwork at the early Acheulean site of EF-HR (Olduvai Gorge, Tanzania) has included detailed stratigraphic studies of the sequence, extended excavations in the main site, and has placed eleven additional trenches within an area of nearly 1 km(2), to sample the same stratigraphic interval as in the main trench across the broader paleo-landscape. Our new stratigraphic work suggests that EF-HR is positioned higher in the Bed II sequence than previously proposed, which has implications for the age of the site and its stratigraphic correlation to other Olduvai Middle Bed II sites...
August 3, 2017: Journal of Human Evolution
https://www.readbyqxmd.com/read/28763202/paleo-ecotoxicology-what-can-lake-sediments-tell-us-about-ecosystem-responses-to-environmental-pollutants
#5
Jennifer Korosi, Joshua R Thienpont, John P Smol, Jules M Blais
The development of effective risk reduction strategies for aquatic pollutants requires a comprehensive understanding of toxic impacts on ecosystems. Classical toxicological studies are effective for characterizing pollutant impacts on biota in a controlled, simplified environment. Nonetheless, it is well-acknowledged that predictions based on the results of these studies must be tested over the long-term in a natural ecosystem setting, to account for increased complexity and multiple stressors. Paleolimnology (the study of lake sediment cores to reconstruct environmental change) can address many key knowledge gaps...
August 1, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28753265/correction-to-drug-delivery-systems-based-on-hydroxyethyl-starch
#6
Constantinos M Paleos, Zili Sideratou, Dimitris Tsiourvas
No abstract text is available yet for this article.
August 16, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28743759/anatolian-origins-and-diversification-of-aethionema-the-sister-lineage-of-the-core-brassicaceae
#7
Setareh Mohammadin, Kim Peterse, Sara J van de Kerke, Lars W Chatrou, Ali A Dönmez, Klaus Mummenhoff, J Chris Pires, Patrick P Edger, Ihsan A Al-Shehbaz, M Eric Schranz
PREMISE OF THE STUDY: The Irano-Turanian region harbors three biodiversity hotspots and ∼25% of Brassicaceae species are endemic to the region. Aethionema (∼61 species) is the sister lineage to the core Brassicaceae and occurs mainly in the Irano-Turanian region. The evolutionary important position of Aethionema makes it an ideal reference for broader comparative genetics and genomics. To understand the evolution of Aethionema, and for a broader understanding of crucifer evolution, a time-calibrated phylogenetic tree and biogeographical history of the genus is needed...
July 25, 2017: American Journal of Botany
https://www.readbyqxmd.com/read/28742864/limited-grounding-line-advance-onto-the-west-antarctic-continental-shelf-in-the-easternmost-amundsen-sea-embayment-during-the-last-glacial-period
#8
Johann P Klages, Gerhard Kuhn, Claus-Dieter Hillenbrand, James A Smith, Alastair G C Graham, Frank O Nitsche, Thomas Frederichs, Patrycja E Jernas, Karsten Gohl, Lukas Wacker
Precise knowledge about the extent of the West Antarctic Ice Sheet (WAIS) at the Last Glacial Maximum (LGM; c. 26.5-19 cal. ka BP) is important in order to 1) improve paleo-ice sheet reconstructions, 2) provide a robust empirical framework for calibrating paleo-ice sheet models, and 3) locate potential shelf refugia for Antarctic benthos during the last glacial period. However, reliable reconstructions are still lacking for many WAIS sectors, particularly for key areas on the outer continental shelf, where the LGM-ice sheet is assumed to have terminated...
2017: PloS One
https://www.readbyqxmd.com/read/28704453/historical-%C3%AE-15n-records-of-saccharina-specimens-from-oligotrophic-waters-of-japan-sea-hokkaido
#9
Takanori Kuribayashi, Tsuyoshi Abe, Shigeru Montani
Historically Saccharina spp. beds occurred along the west coast of Hokkaido, an oligotrophic area, and were commercially exploited. Currently extensive commercial Saccharina spp. beds do not form due to nutrient limitations. Here, we postulate that nutrients assimilated by paleo-Saccharina spp. beds may have been derived from spawning herrings (Clupea pallasii) acting as organisms that formed a vector from their feeding grounds (Okhotsk Sea and Pacific Ocean) to their spawning area (west coast of Hokkaido, Japan Sea)...
2017: PloS One
https://www.readbyqxmd.com/read/28698659/abrupt-emergence-of-a-large-pockmark-field-in-the-german-bight-southeastern-north-sea
#10
Knut Krämer, Peter Holler, Gabriel Herbst, Alexander Bratek, Soeren Ahmerkamp, Andreas Neumann, Alexander Bartholomä, Justus E E van Beusekom, Moritz Holtappels, Christian Winter
A series of multibeam bathymetry surveys revealed the emergence of a large pockmark field in the southeastern North Sea. Covering an area of around 915 km(2), up to 1,200 pockmarks per square kilometer have been identified. The time of emergence can be confined to 3 months in autumn 2015, suggesting a very dynamic genesis. The gas source and the trigger for the simultaneous outbreak remain speculative. Subseafloor structures and high methane concentrations of up to 30 μmol/l in sediment pore water samples suggest a source of shallow biogenic methane from the decomposition of postglacial deposits in a paleo river valley...
July 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28696425/microbial-survival-strategies-in-ancient-permafrost-insights-from-metagenomics
#11
Rachel Mackelprang, Alexander Burkert, Monica Haw, Tara Mahendrarajah, Christopher H Conaway, Thomas A Douglas, Mark P Waldrop
In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr)...
July 11, 2017: ISME Journal
https://www.readbyqxmd.com/read/28696409/a-global-multiproxy-database-for-temperature-reconstructions-of-the-common-era
#12
(no author information available yet)
Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial...
July 11, 2017: Scientific Data
https://www.readbyqxmd.com/read/28681844/sea-level-fall-during-glaciation-stabilized-atmospheric-co2-by-enhanced-volcanic-degassing
#13
Jörg Hasenclever, Gregor Knorr, Lars H Rüpke, Peter Köhler, Jason Morgan, Kristin Garofalo, Stephen Barker, Gerrit Lohmann, Ian R Hall
Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO2, which may have modulated the climate system's descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO2, instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable...
July 6, 2017: Nature Communications
https://www.readbyqxmd.com/read/28641809/re-emerging-infectious-diseases-from-the-past-hysteria-or-real-risk
#14
Charlier Philippe, Claverie Jean-Michel, Sansonetti Philippe, Coppens Yves, Augias Anaïs, Jacqueline Sophie, Rengot Fanny, Deo Saudamini
BACKGROUND: Work on human remains and old biological samples is a potential source of contamination by conventional or atypical infectious agents. Similarly, current and future environmental changes are a source of resurgence of ancient epidemic diseases. To what extent are anthropologists sorcerer apprentices (especially those working on ancient samples, i.e. paleo-anthropologists)? Are ancient skeletons, palaeosols and museum objects with a biological component at risk for current populations? Unless there are unfounded fears and undue risk… What can be learned from the recent scientific literature and the common sense of the researchers? METHODS: We have attempted to compile data from the literature and from our personal experience in the fields of anthropology, clinical medicine and epidemiology, in order to grasp the reality of the risk to the human population...
June 19, 2017: European Journal of Internal Medicine
https://www.readbyqxmd.com/read/28616163/a-genomic-assessment-of-species-boundaries-and-hybridization-in-a-group-of-highly-polymorphic-anoles-distichus-species-complex
#15
Daniel J MacGuigan, Anthony J Geneva, Richard E Glor
Delimiting young species is one of the great challenges of systematic biology, particularly when the species in question exhibit little morphological divergence. Anolis distichus, a trunk anole with more than a dozen subspecies that are defined primarily by dewlap color, may actually represent several independent evolutionary lineages. To test this, we utilized amplified fragment length polymorphisms (AFLP) genome scans and genetic clustering analyses in conjunction with a coalescent-based species delimitation method...
June 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28607415/molecular-phylogenies-indicate-a-paleo-tibetan-origin-of-himalayan-lazy-toads-scutiger
#16
Sylvia Hofmann, Matthias Stöck, Yuchi Zheng, Francesco G Ficetola, Jia-Tang Li, Ulrich Scheidt, Joachim Schmidt
The Himalaya presents an outstanding geologically active orogen and biodiversity hotspot. However, our understanding of the historical biogeography of its fauna is far from comprehensive. Many taxa are commonly assumed to have originated from China-Indochina and dispersed westward along the Himalayan chain. Alternatively, the "Tibetan-origin hypothesis" suggests primary diversification of lineages in Paleo-Tibet, and secondary diversification along the slopes of the later uplifted Greater Himalaya. We test these hypotheses in high-mountain megophryid anurans (Scutiger)...
June 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28607045/mio-pliocene-aridity-in-the-south-central-andes-associated-with-southern-hemisphere-cold-periods
#17
William H Amidon, G Burch Fisher, Douglas W Burbank, Patricia L Ciccioli, Ricardo N Alonso, Andrew L Gorin, Perri H Silverhart, Andrew R C Kylander-Clark, Michael S Christoffersen
Although Earth's climate history is best known through marine records, the corresponding continental climatic conditions drive the evolution of terrestrial life. Continental conditions during the latest Miocene are of particular interest because global faunal turnover is roughly synchronous with a period of global glaciation from ∼6.2-5.5 Ma and with the Messinian Salinity Crisis from ∼6.0-5.3 Ma. Despite the climatic and ecological significance of this period, the continental climatic conditions associated with it remain unclear...
June 20, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28603673/a-methodology-of-theropod-print-replication-utilising-the-pedal-reconstruction-of-australovenator-and-a-simulated-paleo-sediment
#18
Matt A White, Alex G Cook, Steven J Rumbold
Distinguishing the difference between theropod and ornithopod footprints has proved a difficult task due to their similarities. Herein our aim was to produce a method where a skeleton could be more closely matched to actual fossilised footprints. The reconstructed pes of the Australian Megaraptoran Australovenator wintonensis was utilised for this footprint reconstruction. It was 3-D printed in life size, molded and cast to produce a flexible theropod foot for footprint creation. The Dinosaur Stampede National Monument, Lark Quarry, Queensland, Australia was used as our case study to compare fossilised dinosaur footprints with our reconstructed theropod prints...
2017: PeerJ
https://www.readbyqxmd.com/read/28598413/anthropogenic-climate-change-has-altered-primary-productivity-in-lake-superior
#19
M D O'Beirne, J P Werne, R E Hecky, T C Johnson, S Katsev, E D Reavie
Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production...
June 9, 2017: Nature Communications
https://www.readbyqxmd.com/read/28585926/a-monthly-global-paleo-reanalysis-of-the-atmosphere-from-1600-to-2005-for-studying-past-climatic-variations
#20
Jörg Franke, Stefan Brönnimann, Jonas Bhend, Yuri Brugnara
Climatic variations at decadal scales such as phases of accelerated warming or weak monsoons have profound effects on society and economy. Studying these variations requires insights from the past. However, most current reconstructions provide either time series or fields of regional surface climate, which limit our understanding of the underlying dynamics. Here, we present the first monthly paleo-reanalysis covering the period 1600 to 2005. Over land, instrumental temperature and surface pressure observations, temperature indices derived from historical documents and climate sensitive tree-ring measurements were assimilated into an atmospheric general circulation model ensemble using a Kalman filtering technique...
June 6, 2017: Scientific Data
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