2,323 research outputs found

    Climate Change and Threatened Heritage: Archaeology\u27s Burden

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    Climate change and archaeology are currently intertwined, as more and more archaeologists around the world must deal with the effects it causes on the sites they work on. Threatened cultural resource sites are being swept away at alarming rates, and excavation projects are becoming more and more like salvage digs

    The Socially Constructive Aspects of Outside Agents in Community Decision-Making in a Rural Area

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    The outside-change agent is dangerous, something to be feared (based on past experiences, long since blurred by boredom and powerlessness) and not taken into the community. The outsider offers few, if any, tangible immediately useable resources -- only promises and fancy talk. Limited experience has taught the Appalachian that promises fade into misery and fancy talk to poverty. The self-fulfilling prophesy of inhospitality and disbelief in oneself, turn the Appalachian against the change agent and challenge the agent to leave the area out of self-felt persistent futility

    Post-Emergence Movements and Overwintering of Snapping Turtle, Chelydra serpentina, Hatchlings in New York and New Hampshire

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    Hatchling Common Snapping Turtles (Chelydra serpentina) were captured within, or as they emerged from, their nest cavities in Long Island, New York, and in southeastern New Hampshire. They were fitted with radiotransmitters and released at their nest sites. Their movements were monitored for as long as possible, which for some included tracking them to their overwintering sites and relocating them the following spring. On Long Island, all hatchlings initially moved to water. Later movements were both aquatic and terrestrial, and those that could be located while overwintering had left the water and hibernated in spring seeps, where they were recovered alive the following April. In New Hampshire, hatchlings moved directly to nearby aquatic habitats after emergence, where they spent the winter submerged in shallow water in root masses near banks

    Recruitment, growth and mortality of an Antarctic hexactinellid sponge, Anoxycalyx joubini.

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    Polar ecosystems are sensitive to climate forcing, and we often lack baselines to evaluate changes. Here we report a nearly 50-year study in which a sudden shift in the population dynamics of an ecologically important, structure-forming hexactinellid sponge, Anoxycalyx joubini was observed. This is the largest Antarctic sponge, with individuals growing over two meters tall. In order to investigate life history characteristics of Antarctic marine invertebrates, artificial substrata were deployed at a number of sites in the southern portion of the Ross Sea between 1967 and 1975. Over a 22-year period, no growth or settlement was recorded for A. joubini on these substrata; however, in 2004 and 2010, A. joubini was observed to have settled and grown to large sizes on some but not all artificial substrata. This single settlement and growth event correlates with a region-wide shift in phytoplankton productivity driven by the calving of a massive iceberg. We also report almost complete mortality of large sponges followed over 40 years. Given our warming global climate, similar system-wide changes are expected in the future

    Where people shop is not associated with the nutrient quality of packaged foods for any racial-ethnic group in the United States

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    Background: In the literature, it has been suggested that there are race-ethnic disparities in what Americans eat. In addition, some studies have shown that residents of African American and low-income neighborhoods have less access to grocery stores and supermarkets, which tend to stock healthier foods. However, it is unclear whether differences in food shopping patterns contribute to the poorer nutrient profile of food purchases made by racial-ethnic minorities

    Extending the sub-sea-floor biosphere

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    En libre-accès sur Archimer : http://archimer.ifremer.fr/doc/2008/publication-4209.pdfInternational audienceSub-sea-floor sediments may contain two-thirds of Earth's total prokaryotic biomass. However, this has its basis in data extrapolation from ~500-meter to 4-kilometer depths, whereas the deepest documented prokaryotes are from only 842 meters. Here, we provide evidence for low concentrations of living prokaryotic cells in the deepest (1626 meters below the sea floor), oldest (111 million years old), and potentially hottest (~100 degrees C) marine sediments investigated. These Newfoundland margin sediments also have DNA sequences related to thermophilic and/or hyperthermophilic Archaea. These form two unique clusters within Pyrococcus and Thermococcus genera, suggesting unknown, uncultured groups are present in deep, hot, marine sediments (~54 degrees to 100 degrees C). Sequences of anaerobic methane-oxidizing Archaea were also present, suggesting a deep biosphere partly supported by methane. These findings demonstrate that the sub-sea-floor biosphere extends to at least 1600 meters below the sea floor and probably deeper, given an upper temperature limit for prokaryotic life of at least 113 degrees C and increasing thermogenic energy supply with depth

    Beyond Supermarkets: Food Outlet Location Selection in Four U.S. Cities Over Time

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    Understanding what influences where food outlets locate is important for mitigating disparities in access to healthy food outlets. However, few studies have examined how neighborhood characteristics influence the neighborhood food environment over time, and whether these relationships differ by neighborhood-level income

    Sobre a Faixa de Pedestres

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    The interference colors resulting from thin films of Al 2O 3 deposited by atomic layer deposition (ALD) on silicon have been rigorously analyzed using a recently developed robotic gonioreflectometer. A series of eleven increasingly thick films was deposited, up to 1613 Ã…, and their reflectance values obtained for the visible spectrum. A comparison of these values with the predictions of computer simulations employing Fresnel equations has revealed that while there was generally good agreement between predicted and measured spectra, there are some spectral regions that exhibit large deviations from predicted reflectances, typically at near-normal measurement angles and shorter wavelengths. The effect of these discrepancies on color appearance was investigated in the CIE L*a*b* color space for the daylight illuminant D65. Large iridescence is both predicted and measured for most film thicknesses. Chroma and hue differences as large as 20 CIELAB units between the predicted and the measured color centers were obtained. Simulation also predicts larger iridescence than what is actually measured. A likely cause for the observed discrepancies is that the dielectric constants of the ALD films deviate from the literature values for the bulk material

    A general algorithm for manipulating non-linear and linear entanglement witnesses by using exact convex optimization

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    A generic algorithm is developed to reduce the problem of obtaining linear and nonlinear entanglement witnesses of a given quantum system, to convex optimization problem. This approach is completely general and can be applied for the entanglement detection of any N-partite quantum system. For this purpose, a map from convex space of separable density matrices to a convex region called feasible region is defined, where by using exact convex optimization method, the linear entanglement witnesses can be obtained from polygonal shape feasible regions, while for curved shape feasible regions, envelope of the family of linear entanglement witnesses can be considered as nonlinear entanglement witnesses. This method proposes a new methodological framework within which most of previous EWs can be studied. To conclude and in order to demonstrate the capability of the proposed approach, besides providing some nonlinear witnesses for entanglement detection of density matrices in unextendible product bases, W-states, and GHZ with W-states, some further examples of three qubits systems and their classification and entanglement detection are included. Also it is explained how one can manipulate most of the non-decomposable linear and nonlinear three qubits entanglement witnesses appearing in some of the papers published by us and other authors, by the method proposed in this paper. Keywords: non-linear and linear entanglement witnesses, convex optimization. PACS number(s): 03.67.Mn, 03.65.UdComment: 37 page
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