1,762 research outputs found

    Review of \u3ci\u3e Principles of Geoarchaeology: A North American Perspective\u3c/i\u3e by Michael R. Waters

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    First published in 1992, this book-now in paper-presents the fundamentals of geoarchaeology, the field of study that applies the concepts and methods of the geosciences to archaeological research. Although a number of good books have been written about this subdiscipline of archaeology, Waters restricts his review to late Quaternary landscapes in North America. Furthermore, he limits his discussion to the field aspects of geoarchaeology. Stratigraphy, site formation processes, and landscape reconstruction are the centerpieces of this study. Readers looking for information about laboratory methods, dating techniques, or the application of geophysics and geochemistry to archaeology must go to other sources. Waters\u27s topical, temporal, and geographical focus is, nonetheless, effective, allowing for detailed discussions of geoarchaeological concepts and field methods that are directly applicable to archaeological research in North America. A broader scope would have diluted his effort

    Review of \u3ci\u3e Soils in Archaeological Research\u3c/i\u3e by Vance T. Holliday

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    When I teach geoarchaeology, I tell students on the first day of class that soils are the canvas for much of the archaeological record. Just as an artist\u27s canvas holds and affects the paint, soils hold archaeological materials, and soil-forming processes strongly influence the preservation and spatial pattern of cultural deposits. Given this close relationship between soils and the material remains of humans, we have long needed a treatise that addresses all aspects of soils from an archaeological perspective. Vance Holliday\u27s latest book, Soils in Archaeological Research, does this and more

    Questions of quality in repositories of open educational resources: a literature review

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    Open educational resources (OER) are teaching and learning materials which are freely available and openly licensed. Repositories of OER (ROER) are platforms that host and facilitate access to these resources. ROER should not just be designed to store this content – in keeping with the aims of the OER movement, they should support educators in embracing open educational practices (OEP) such as searching for and retrieving content that they will reuse, adapt or modify as needed, without economic barriers or copyright restrictions. This paper reviews key literature on OER and ROER, in order to understand the roles ROER are said or supposed to fulfil in relation to furthering the aims of the OER movement. Four themes which should shape repository design are identified, and the following 10 quality indicators (QI) for ROER effectiveness are discussed: featured resources; user evaluation tools; peer review; authorship of the resources; keywords of the resources; use of standardised metadata; multilingualism of the repositories; inclusion of social media tools; specification of the creative commons license; availability of the source code or original files. These QI form the basis of a method for the evaluation of ROER initiatives which, in concert with considerations of achievability and long-term sustainability, should assist in enhancement and development. Keywords: open educational resources; open access; open educational practice; repositories; quality assuranc

    Transcriptional profiling of colicin-induced cell death of Escherichia coli MG1655 identifies potential mechanisms by which bacteriocins promote bacterial diversity

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    We report the transcriptional response of Escherichia coli MG1655 to damage induced by colicins E3 and E9, bacteriocins that kill cells through inactivation of the ribosome and degradation of chromosomal DNA, respectively. Colicin E9 strongly induced the LexA-regulated SOS response, while colicin E3 elicited a broad response that included the induction of cold shock genes, symptomatic of translational arrest. Colicin E3 also increased the transcription of cryptic prophage genes and other laterally acquired mobile elements. The transcriptional responses to both these toxins suggest mechanisms that may promote genetic diversity in E. coli populations, pointing to a more general role for colicins in adaptive bacterial physiology than has hitherto been realized

    Driving While High

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    As of May 2019, ten U.S. states and Washington DC have legalized non-medical/recreational use of cannabis. With increased access to legal marijuana across the country, some have raised concerns regarding unintended implications of these policies, such as the risk of motor vehicle crashes, which is the leading cause of mortality and injury among youth and young adults. Driving under the influence of marijuana is particularly concerning among young adults and college students, due to the increased level of substance use reported during the transition from high school to post-high school environments, such as college

    The Charging Structure for the Great Barrier Reef - A review of willingness to pay

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    The Great Barrier Reef Marine Park Authority (GBRMPA or the Reef Authority) is currently conducting a comprehensive review of the charging structure for the use of the Great Barrier Reef (GBR) Marine Park with a view to implement potential changes from 1 July 2023

    Sport psychology consulting in professional rugby union in the United Kingdom

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    This article describes my experiences of working within professional rugby union in South Wales, United Kingdom. Initially, I locate the context of professional rugby union in the country alongside how my various subcultural understandings of the sport were obtained. After outlining my consulting philosophy developed for working in a professional rugby union context, subsequent cultural challenges for practitioners working in the sport are then explored, together with example strategies used to account for such cultural considerations. I conclude by reflecting upon the importance of practitioners possessing and developing contextual intelligence and cultural competency to work effectively in high performance environments

    Systematic Approach to Identifying Deeply Buried Archeological Deposits

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    This project is designed to assist cultural resource specialists involved in Nebraska Department of Transportation (NDOT) and the Federal Highway Administration (FHWA) project planning and development. The goal was to develop Geographic Information System (GIS) data layers that spatially delineate different landform-sediment assemblages (LSAs) and depict the associated geologic potential for buried cultural deposits in select watersheds in Nebraska. The Nebraska Buried Sites GIS resource will allow planners and cultural resource specialists to determine whether future project areas are likely to be free of deeply buried sites or whether subsurface exploration is necessary

    Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response

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    The research presented in this paper focusses on the underwater blast resilience of a hybrid composite sandwich panel, consisting of both glass-fibre and carbon-fibre. The hybrid fibres were selected to optimise strength and stiffness during blast loading by promoting fibre interactions. In the blast experiment, the aim was to capture full-field panel deflection during large-scale underwater blast using high-speed 3D Digital Image Correlation (DIC). The composite sandwich panel was partially submerged and subjected to a 1 kg PE7 charge at 1 m stand-off. The charge was aligned with the centre of the panel at a depth of 275 mm and mimicked the effect of a near-field subsurface mine. The DIC deflection data shows that the horizontal cross-section of the panel deforms in a parabolic shape until excessive deflection causes core shear cracking. The panel then forms the commonly observed “bathtub” deformation shape. DIC data highlighted the expected differences in initial conditions compared to air-blast experiments, including the pre-strains caused by the mass of water (hydrostatic pressure). Furthermore, water depth was shown to significantly influence panel deflection, strain and hence damage sustained under these conditions. Panel deformations and damage after blast was progressively more severe in regions deeper underwater, as pressures were higher and decayed slower compared to regions near the free surface.An identical hybrid composite sandwich panel was subjected to air blast; one panel underwent two 8 kg PE7 charges in succession at 8 m stand-off. DIC was also implemented to record the panel deformations during air blast. The air and underwater blast tests represent two different regimes of blast loading: one far-field in air and one near-field underwater. The difference in deflection development, caused by the differing fluid mediums and stand-off distances, is apparent from the full-field results. During underwater blast the panel underwent peak pressure loading of approximately 52.6 MPa whilst during air blast the panel was subjected to 67.7 kPa followed by 68.9 kPa peak pressure loads in succession. The two experiments demonstrate the response of the same hybrid composite sandwich panel under two differing blast regimes.The post-blast damage and strength of the hybrid panels following air and underwater blasts were evaluated. Post-blast testing revealed that the underwater blast causes significantly more damage compared to air blast, particularly debonding between the skins and core. The air blast panel sustains no visible rear skin/core debonding, whereas 13 regions of rear-face debonds are identified on the underwater blast panel. Sustaining no front-skin breakage was advantageous for retaining a high proportion of the compressive modulus for this hybrid layup following underwater blast. Damage mechanisms were interrelated. Determining the most detrimental type is not straightforward in real explosive and non-idealised experiments, however debonding was understandably shown to be significant. A further study to isolate failure modes and improve in situ instrumentation is ongoing
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