1,913 research outputs found

    The Lord-Collins Site (MAS# 3.12): A Late Pleistocene Human Use of Southeastern Maine, USA

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    Field report on test excavations of a possible Late Pleistocene locality.British Academ

    The Two Cs: Cola de Pescado and Clovis

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    © 2015 W. S. Maney & Son Ltd and the Center for the Study of the First Americans. Author's accepted version deposited in accordance with publisher guidelines. The definitive version is available at http://www.maneyonline.com/doi/abs/10.1179/2055556315Z.00000000014.Perspecitves on the origin of fishtail point technology in South America

    Solutrean hypothesis: genetics, the mammoth in the room

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    © 2014 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis Group in World Archaeology on 31/10/2014, available online: http://www.tandfonline.com/10.1080/00438243.2014.966273.The Solutrean Hypothesis for the origin of the Clovis archaeological culture has received numerous challenges and critiques. Oft-repeated contra-assertions, predominantly from archaeologists, range from: “NO genetic evidence”, to: it must have been either a sole Beringian or European origin, so Beringia wins, to: the troublesome fifth American mtDNA lineage “X2a” overlanded from West-Eurasia to Beringia, leaving no trace en-route, to: there is no evidence from the rest of the genome to parallel X2a. We refute these contra-assertions, detailing published contrary evidence, supporting a West-Eurasian origin for some Native American ancestors, mainly found in north-eastern America, in parallel to the majority arriving from Beringia. Specifically this includes mtDNA-X2a found in ancient and modern Native American populations, with no evidence to support migration of X2a through Siberia. Prima facie (i.e. under-researched) published evidence also exists for equivalent levels of West-Eurasian Y-chromosomes and autosomal markers in the same regions

    Stix and Leaves Pueblo

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    This is an archaeological site report of the excavations at an Ancestral Pueblo site in southwestern Colorado

    The Child Brain Computes and Utilizes Internalized Maternal Choices

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    As children grow, they gradually learn how to make decisions independently. However, decisions like choosing healthy but less-tasty foods can be challenging for children whose self-regulation and executive cognitive functions are still maturing. We propose a computational decision-making process in which children estimate their mother's choices for them as well as their individual food preferences. By employing functional magnetic resonance imaging during real food choices, we find that the ventromedial prefrontal cortex (vmPFC) encodes children's own preferences and the left dorsolateral prefrontal cortex (dlPFC) encodes the projected mom's choices for them at the time of children's choice. Also, the left dlPFC region shows an inhibitory functional connectivity with the vmPFC at the time of children's own choice. Our study suggests that in part, children utilize their perceived caregiver's choices when making choices for themselves, which may serve as an external regulator of decision-making, leading to optimal healthy decisions

    High surface area, low weight composite nickel fiber electrodes

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    The energy density and power density of light weight aerospace batteries utilizing the nickel oxide electrode are often limited by the microstructures of both the collector and the resulting active deposit in/on the collector. Heretofore, these two microstructures were intimately linked to one another by the materials used to prepare the collector grid as well as the methods and conditions used to deposit the active material. Significant weight and performance advantages were demonstrated by Britton and Reid at NASA-LeRC using FIBREX nickel mats of ca. 28-32 microns diameter. Work in our laboratory investigated the potential performance advantages offered by nickel fiber composite electrodes containing a mixture of fibers as small as 2 microns diameter (Available from Memtec America Corporation). These electrode collectors possess in excess of an order of magnitude more surface area per gram of collector than FIBREX nickel. The increase in surface area of the collector roughly translates into an order of magnitude thinner layer of active material. Performance data and advantages of these thin layer structures are presented. Attributes and limitations of their electrode microstructure to independently control void volume, pore structure of the Ni(OH)2 deposition, and resulting electrical properties are discussed

    Defining the risk of human exposure to Australian bat lyssavirus through potential non-bat animal infection

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    Human infection with Australian bat lyssavirus (ABLV) was first reported in November 1996, six months after the first identification of the virus in a flying fox in May 1996. Only two human cases of ABLV infection have been described to date, although hundreds of potential human exposures to ABLV have been reported. Current public health guidance considers the risk of transmission of ABLV from a dog or cat to a person is very low. Furthermore, owners are advised that although the animal has a remote possibility of being infected with ABLV, it should be observed closely for at least three months and to report any behavioural changes that occur. The authors present two cases where the behaviour of dogs after potential exposure to ABLV posed significant questions for veterinary and public health authorities

    The Concreteness of The Invisible

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    The project commenced with the assumption that the manifested physical form of city (the one which we verify through common perception as objectivization of the idea of city) is a deception

    Calibration of remotely sensed, coarse resolution NDVI to CO2 fluxes in a sagebrush–steppe ecosystem

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    The net ecosystem exchange (NEE) of carbon flux can be partitioned into gross primary productivity (GPP) and respiration (R). The contribution of remote sensing and modeling holds the potential to predict these components and map them spatially and temporally. This has obvious utility to quantify carbon sink and source relationships and to identify improved land management strategies for optimizing carbon sequestration. The objective of our study was to evaluate prediction of 14-day average daytime CO2 fluxes ( Fday) and nighttime CO2 fluxes (Rn) using remote sensing and other data. Fday and Rn were measured with a Bowen ratio–energy balance (BREB) technique in a sagebrush (Artemisia spp.)–steppe ecosystem in northeast Idaho, USA, during 1996–1999. Micrometeorological variables aggregated across 14-day periods and time-integrated Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (iNDVI) were determined during four growing seasons (1996–1999) and used to predict Fday and Rn. We found that iNDVI was a strong predictor of Fday (R2= 0.79, n = 66, P \u3c 0.0001). Inclusion of evapotranspiration in the predictive equation led to improved predictions of Fday (R2= 0.82, n = 66, P \u3c 0.0001). Cross-validation indicated that regression tree predictions of Fday were prone to overfitting and that linear regression models were more robust. Multiple regression and regression tree models predicted Rn quite well (R2 = 0.75–0.77, n = 66) with the regression tree model being slightly more robust in cross-validation. Temporal mapping of Fday and Rn is possible with these techniques and would allow the assessment of NEE in sagebrush–steppe ecosystems. Simulations of periodic Fday measurements, as might be provided by a mobile flux tower, indicated that such measurements could be used in combination with iNDVI to accurately predict Fday. These periodic measurements could maximize the utility of expensive flux towers for evaluating various carbon management strategies, carbon certification, and validation and calibration of carbon flux models

    A Proper Motion Study of the Haro 6-10 Outflow: Evidence for a Subarcsecond Binary

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    We present single-dish and VLBI observations of an outburst of water maser emission from the young binary system Haro 6-10. Haro 6-10 lies in the Taurus molecular cloud and contains a visible T Tauri star with an infrared companion 1.3" north. Using the Very Long Baseline Array, we obtained five observations spanning 3 months and derived absolute positions for 20 distinct maser spots. Three of the masers can be traced over 3 or more epochs, enabling us to extract absolute proper motions and tangential velocities. We deduce that the masers represent one side of a bipolar outflow that lies nearly in the plane of the sky with an opening angle of ~45\deg. They are located within 50 mas of the southern component of the binary, the visible T Tauri star Haro 6-10S. The mean position angle on the sky of the maser proper motions (~220\deg) suggests they are related to the previously observed giant Herbig-Haro (HH) flow which includes HH410, HH411, HH412, and HH184A-E. A previously observed HH jet and extended radio continuum emission (mean position angle of ~190\deg) must also originate in the vicinity of Haro6-10S and represent a second, distinct outflow in this region. We propose that a yet unobserved companion within 150 mas of Haro6-10S is responsible for the giant HH/maser outflow while the visible star is associated with the HH jet. Despite the presence of H_2 emission in the spectrum of the northern component of the binary, Haro6-10N, none of outflows/jets can be tied directly to this young stellar object
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