3,649 research outputs found

    Hydrological controls of in situ preservation of waterlogged archaeological deposits

    Get PDF
    Environmental change caused by urban development, land drainage, agriculture or climate change may result in accelerated decay of in situ archaeological remains. This paper reviews research into impacts of environmental change on hydrological processes of relevance to preservation of archaeological remains in situ. It compares work at rural sites with more complex urban environments. The research demonstrates that both the quantity and quality of data on preservation status, and hydrological and chemical parameters collected during routine archaeological surveys need to be improved. The work also demonstrates the necessity for any archaeological site to be placed within its topographic and geological context. In order to understand preservation potential fully, it is necessary to move away from studying the archaeological site as an isolated unit, since factors some distance away from the site of interest can be important for determining preservation. The paper reviews what is known about the hydrological factors of importance to archaeological preservation and recommends research that needs to be conducted so that archaeological risk can be more adequately predicted and mitigated. Any activity that changes either source pathways or the dominant water input may have an impact not just because of changes to the water balance or the water table, but because of changes to water chemistry. Therefore, efforts to manage threatened waterlogged environments must consider the chemical nature of the water input into the system. Clearer methods of assessing the degree to which buried archaeological sites can withstand changing hydrological conditions are needed, in addition to research which helps us understand what triggers decay and what controls thresholds of response for different sediments and types of artefact

    The H1 Forward Track Detector at HERA II

    Full text link
    In order to maintain efficient tracking in the forward region of H1 after the luminosity upgrade of the HERA machine, the H1 Forward Track Detector was also upgraded. While much of the original software and techniques used for the HERA I phase could be reused, the software for pattern recognition was completely rewritten. This, along with several other improvements in hit finding and high-level track reconstruction, are described in detail together with a summary of the performance of the detector.Comment: Minor revision requested by journal (JINST) edito

    Out-of-Distribution Generalization in Algorithmic Reasoning Through Curriculum Learning

    Full text link
    Out-of-distribution generalization (OODG) is a longstanding challenge for neural networks, and is quite apparent in tasks with well-defined variables and rules, where explicit use of the rules can solve problems independently of the particular values of the variables. Large transformer-based language models have pushed the boundaries on how well neural networks can generalize to novel inputs, but their complexity obfuscates they achieve such robustness. As a step toward understanding how transformer-based systems generalize, we explore the question of OODG in smaller scale transformers. Using a reasoning task based on the puzzle Sudoku, we show that OODG can occur on complex problems if the training set includes examples sampled from the whole distribution of simpler component tasks

    Eye movement desensitization and reprocessing : an evaluation of single session treatment of test anxiety

    Get PDF
    Eye movement desensitization and reprocessing (EMDR) is a structured comprehensive therapeutic procedure that appears to desensitize the distressing emotions related to past disturbing and traumatic events, while simultaneously restructuring related negative cognitions and relieving accompanying physiological hyperarousal. This study evaluated the effectiveness of a single ninety minute EMDR session in reducing the symptoms and anxiety associated with test anxiety. It was hypothesized that EMDR would effectively treat test anxiety by alleviating physiological distress, eliminating negative self-preoccupied cognitions, and decreasing the fear of negative evaluation. Seventeen second-year psychology students with test anxiety were randomly assigned to Immediate treatment and Delayed treatment conditions. Standardized objective measures (the Test Anxiety Inventory [TAI], the Fear of Negative Evaluation Scale, and the State Trait Anxiety Inventory) were taken pre- and post-treatment and at two-month follow-up. Results showed that EMDR significantly decreased the symptoms of test anxiety and evaluation fears of the Immediate group compared to the Delayed group, with effects being maintained at two-month follow-up. Large treatment effects were achieved and were reflected in large drops in percentile ranking on the TAI. The Subjective Units of Disturbance Scale and Validity of Cognition ratings also improved significantly, showing large treatment effects, which is consistent with Shapiro’s findings of rapid and significant reductions in presenting complaints and anxiety. When the Delayed group received treatment, it was found that the effects of treatment were equivalent for the two groups. One session of EMDR appears to be an effective treatment for test anxiety for students

    How tropical epiphytes at the Eden Project contribute to rainforest canopy science

    Get PDF
    Understanding the ecological patterns and ecosystem processes of tropical rainforest canopies is becoming increasingly urgent in the face of widespread deforestation. However, accessing rainforest canopies is far from simple, and performing manipulative experiments in the canopy is particularly challenging. Botanic gardens provide an ideal ‘halfway house’ between field experiments and controlled laboratory conditions. As an ideal venue for testing equipment and refining ideas, botanic gardens also provide scientists with a direct route to public engagement, and potentially to research impact. Here we describe the ‘fernarium’, an adjustable canopy research platform for the standardisation, manipulation and detailed study of epiphytic bird’s nest ferns (Asplenium nidus) at the Eden Project in Cornwall. The fernarium provides a platform not only for the scientific study of bird’s nest ferns, but for public engagement, science communication and a wider understanding of the urgent environmental issues surrounding tropical rainforests. We include some preliminary resultsfrom an experiment in which the microbial community of a fern soil at the Eden Project was found to be similar in composition to that of a fern from lowland tropical rainforest in Malaysian Borneo. This study illustrates how preliminary experiments in an indoor rainforest can inform experimental techniques and procedures fundamental to the scientific study of genuine rainforest canopies

    Molecular motion in cell membranes: analytic study of fence-hindered random walks

    Full text link
    A theoretical calculation is presented to describe the confined motion of transmembrane molecules in cell membranes. The study is analytic, based on Master equations for the probability of the molecules moving as random walkers, and leads to explicit usable solutions including expressions for the molecular mean square displacement and effective diffusion constants. One outcome is a detailed understanding of the dependence of the time variation of the mean square displacement on the initial placement of the molecule within the confined region. How to use the calculations is illustrated by extracting (confinement) compartment sizes from experimentally reported published observations from single particle tracking experiments on the diffusion of gold-tagged G-protein coupled mu-opioid receptors in the normal rat kidney cell membrane, and by further comparing the analytical results to observations on the diffusion of phospholipids, also in normal rat kidney cells.Comment: 10 pages, 5 figure
    • …
    corecore