The Thule Migrations as an Analog for the Early Peopling of the Americas: Evaluating Scenarios of Overkill, Trade, Climate Forcing, and Scalar Stress

The mountain systems are characterized by diverse ecological conditions (climate, geomorphological, soil, etc.). The wide spectrum of environmental conditions entails a rich diversity of plant communities growing on the small territory and determines the different flora and vegetation geneses. The uniqueness of floristic and coenotic diversities of the high-mountain vegetation of the south of Western Altai (Ivanovskiy, Prokhodnoi, and Rossypnoi Ranges) are associated with the effect of two climate-forcing factors such as the westerly humid air mass and dry warm airflow from the inner Kazakhstan regions. The paper summarizes the data on coenotic diversity (Zibzeev, 2010, 2012) and gives a syntaxonomic analysis of the high-mountain vegetation in the Ivanovskii, Prokhodnoi, and Rossypnoi Ranges (Western Altai, Kazakhstan). The classification of plant communities was carried out using the Braun-Blanquet approach (Westhoff, van der Maarel, 1973). The relevés records were stored in the TURBOVEG database and classified by TWINSPAN (Hill 1979).

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UNCERTAINTY FROM CLIMATE FORCING OF PROJECTIONS IN GLACIER MELT FOR HIGH MOUNTAIN ASIA

Journal of Japan Society of Civil Engineers Ser B1 (Hydraulic Engineering) ◽

10.2208/jscejhe.74.i_211 ◽

2018 ◽

Vol 74 (4) ◽

pp. I_211-I_216

Author(s):

Megumi WATANABE ◽

Aki YANAGAWA ◽

Yukiko HIRABAYASHI ◽

Satoshi WATANABE ◽

Akiko SAKAI ◽

...

Keyword(s):

Climate Forcing ◽

High Mountain ◽

Glacier Melt

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The Relevance of Old World Archaeology to the First Entry of Man into New Worlds: Colonization Seen from the Antipodes

Quaternary Research ◽

10.1016/0033-5894(77)90060-6 ◽

1977 ◽

Vol 8 (1) ◽

pp. 128-148 ◽

Cited By ~ 24

Author(s):

Sylvia J. Hallam

Keyword(s):

Demographic Data ◽

Ecological Zones ◽

The North ◽

Technological Potential ◽

The Pacific ◽

Peopling Of The Americas ◽

Rapid Spread ◽

History Of ◽

Economic Innovation ◽

Considerable Complexity

Following several discussions in recent numbers of Quaternary Research on the peopling of the Americas, this paper suggests that movements into the New World should be viewed in the wider context of subsistence, technology, and movement around the western littorals of the Pacific, resulting in the colonization not of one but of two new continents by men out of Asia. Specific points which have been raised by these recent papers are reviewed in the light of Australian, Wallacian, and East Asian data.(1) The earliness of watercraft is evidenced by chronology of the human diaspora through Wallacia and Greater Australia.(2) The simplistic nomenclature of chopper-flake traditions masks considerable complexity and technological potential, revealed in detailed Antipodean studies.(3) These traditions also have great potential for adapting to differing ecological zones, evidenced within Greater Australia; and for technological and economic innovation there, through Southeast Asia, and to Japan and the north Asian littoral.(4) The history of discovery and the nature of the evidence from Australia cannot validly be used to controvert early dates in the Americas.(5) Demographic data from Australia suggest that total commitment to a rapid-spread “bowwave” model for the peopling of new continents may be unwise.

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Equivalent Scalar Stress Formulation Taking into Account Non-Resolved Turbulent Scales

Cardiovascular Engineering and Technology ◽

10.1007/s13239-021-00526-x ◽

2021 ◽

Author(s):

Lucas Konnigk ◽

Benjamin Torner ◽

Martin Bruschewski ◽

Sven Grundmann ◽

Frank-Hendrik Wurm

Keyword(s):

Mechanical Stress ◽

Turbulence Models ◽

Turbulent Channel Flow ◽

Simulation Method ◽

Blood Damage ◽

Stress Calculation ◽

High Risk Factors ◽

Cardiovascular Engineering ◽

Scalar Stress ◽

Definition Of

Abstract Purpose Cardiovascular engineering includes flows with fluid-dynamical stresses as a parameter of interest. Mechanical stresses are high-risk factors for blood damage and can be assessed by computational fluid dynamics. By now, it is not described how to calculate an adequate scalar stress out of turbulent flow regimes when the whole share of turbulence is not resolved by the simulation method and how this impacts the stress calculation. Methods We conducted direct numerical simulations (DNS) of test cases (a turbulent channel flow and the FDA nozzle) in order to access all scales of flow movement. After validation of both DNS with literature und experimental data using magnetic resonance imaging, the mechanical stress is calculated as a baseline. Afterwards, same flows are calculated using state-of-the-art turbulence models. The stresses are computed for every result using our definition of an equivalent scalar stress, which includes the influence from respective turbulence model, by using the parameter dissipation. Afterwards, the results are compared with the baseline data. Results The results show a good agreement regarding the computed stress. Even when no turbulence is resolved by the simulation method, the results agree well with DNS data. When the influence of non-resolved motion is neglected in the stress calculation, it is underpredicted in all cases. Conclusion With the used scalar stress formulation, it is possible to include information about the turbulence of the flow into the mechanical stress calculation even when the used simulation method does not resolve any turbulence.

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New AMS Radiocarbon Ages from the Preceramic Levels of Coxcatlan Cave, Puebla, Mexico: A Pleistocene Occupation of the Tehuacan Valley?

Latin American Antiquity ◽

10.1017/laq.2021.26 ◽

2021 ◽

pp. 1-15

Author(s):

Andrew D. Somerville ◽

Isabel Casar ◽

Joaquín Arroyo-Cabrales

Keyword(s):

Mass Spectrometry ◽

Last Glacial Maximum ◽

Food Production ◽

Tehuacán Valley ◽

Rock Shelter ◽

Last Glacial ◽

Tehuacan Valley ◽

Peopling Of The Americas ◽

The Last Glacial Maximum ◽

The Last Glacial

Archaeological studies at Coxcatlan Cave in the Tehuacan Valley of southern Puebla, Mexico, have been instrumental to the development of the chronology for the region and for our understanding of the origins of food production in the Americas. This article refines the Preceramic chronology of the Tehuacan Valley by presenting 14 new accelerated mass spectrometry (AMS) radiocarbon ages from faunal bone samples uncovered from early depositional levels of the rock shelter. Although bones associated with the El Riego (9893–7838 cal BP), Coxcatlan (7838–6375 cal BP), and Abejas (6375–4545 cal BP) phase zones of the cave yielded ages similar to those of the previously proposed chronology for the region, bones from the Ajuereado phase zones at the base of the cave yielded surprisingly old ages that range from 33,448 to 28,279 cal BP, a time prior to the Last Glacial Maximum. Because these early ages are many thousands of years older than current models estimate for the peopling of the Americas, they require reassessments of the artifacts and ecofacts excavated from these early zones.

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Assessment of Emissions from Residential Combustion in Southeast Asia and Implications for Climate Forcing Potential

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147311 ◽

2021 ◽

pp. 147311

Author(s):

Lai Nguyen Huy ◽

Ekbordin Winijkul ◽

Nguyen Thi Kim Oanh

Keyword(s):

Southeast Asia ◽

Climate Forcing ◽

Residential Combustion

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Modeling of Carbonyl/Ammonium Sulfate Aqueous Brown Carbon Chemistry via UV/Vis Spectral Decomposition

Atmosphere ◽

10.3390/atmos11040358 ◽

2020 ◽

Vol 11 (4) ◽

pp. 358 ◽

Cited By ~ 3

Author(s):

Mengjie Fan ◽

Shiqing Ma ◽

Nahin Ferdousi ◽

Ziwei Dai ◽

Joseph L. Woo

Keyword(s):

Climate Forcing ◽

Reaction Products ◽

Brown Carbon ◽

Reaction Systems ◽

Reaction Rate Constants ◽

Kinetic Information ◽

First Order Kinetics ◽

Aggregate Effect ◽

Light Absorbance

The proper characterization of aqueous brown carbon (BrC) species, their formation, and their light absorbance properties is critical to understanding the aggregate effect that they have on overall atmospheric aerosol climate forcing. The contribution of dark chemistry secondary organic aerosol (SOA) products from carbonyl-containing organic compounds (CVOCs) to overall aqueous aerosol optical properties is expected to be significant. However, the multiple, parallel pathways that take place within CVOC reaction systems and the differing chromophoricity of individual products complicates the ability to reliably model the chemical kinetics taking place. Here, we proposed an alternative method of representing UV-visible absorbance spectra as a composite of Gaussian lineshape functions to infer kinetic information. Multiple numbers of curves and different CVOC/ammonium reaction systems were compared. A model using three fitted Gaussian curves with magnitudes following first-order kinetics achieved an accuracy within 65.5% in the 205–300-nm range across multiple organic types and solution aging times. Asymmetrical peaks that occurred in low-200-nm wavelengths were decomposed into two overlapping Gaussian curves, which may have been attributable to different functional groups or families of reaction products. Component curves within overall spectra exhibited different dynamics, implying that the utilization of absorbance at a single reference wavelength to infer reaction rate constants may result in misrepresentative kinetics for these systems.

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