Centrifuge modelling of the ground reaction curve of fibre reinforced soil

The phenomenon known as the 'arching effect' occurs when a portion of granular mass yields relative to an adjacent stationary region. The movement is resisted by shearing stresses which act to reduce the pressure on the yielding support and increase the pressure on the adjacent stationary supporting zones. Arching is widely observed in both natural and man-made structures such as piled embankments, tunnels, and above mine works and sinkholes. One method of increasing soil shear strength and its resistance to deformation is through the use of randomly distributed discrete fibres. The degree of improvement has been shown to be directly related to the fibre content in the soil, the fibre aspect ratio, orientation and mechanical properties. In this research the arching effect is recreated in a geotechnical centrifuge model using a 'trapdoor' apparatus within a plane strain container and the effect of fibre reinforcement on results is examined. Both the trapdoor and an adjacent support were instrumented to measure the force (and derived pressure) distribution. Soil and trapdoor displacements were determined using digital image analysis. The influence of fibre content is examined whilst maintaining constant fibre length, applied compactive effort, and soil height

Experimental techniques for ductile damage characterisation

Ductile damage in metallic materials is caused by the nucleation, growth and coalesce of voids and micro-cracks in the metal matrix when it is subjected to plastic strain. A considerable number of models have been proposed to represent ductile failure focusing on the ultimate failure conditions; however, only some of them study in detail the whole damage accumulation process. The aim of this work is to review experimental techniques developed by various authors to measure the accumulation of ductile damage under tensile loads. The measurement methods reviewed include: stiffness degradation, indentation, microstructure analysis, ultrasonic waves propagation, X-ray tomography and electrical potential drop. Stiffness degradation and indentation techniques have been tested on stainless steel 304L hourglass-shaped samples. A special interest is placed in the Continuum Damage Mechanics approach (CDM) as its equations incorporate macroscopic parameters that can represent directly the damage accumulation measured in the experiments. The other main objective lies in identifying the strengths and weaknesses of each technique for the assessment of materials subjected to different strain-rate and temperature conditions

Land-surface parameter optimisation using data assimilation techniques: The adJULES system V1.0

This is the final version of the article. Available from the European Geosciences Union (EGU) via the DOI in this record.Land-surface models (LSMs) are crucial components of the Earth system models (ESMs) that are used to make coupled climate-carbon cycle projections for the 21st century. The Joint UK Land Environment Simulator (JULES) is the land-surface model used in the climate and weather forecast models of the UK Met Office. JULES is also extensively used offline as a land-surface impacts tool, forced with climatologies into the future. In this study, JULES is automatically differentiated with respect to JULES parameters using commercial software from FastOpt, resulting in an analytical gradient, or adjoint, of the model. Using this adjoint, the adJULES parameter estimation system has been developed to search for locally optimum parameters by calibrating against observations. This paper describes adJULES in a data assimilation framework and demonstrates its ability to improve the model-data fit using eddy-covariance measurements of gross primary production (GPP) and latent heat (LE) fluxes. adJULES also has the ability to calibrate over multiple sites simultaneously. This feature is used to define new optimised parameter values for the five plant functional types (PFTs) in JULES. The optimised PFT-specific parameters improve the performance of JULES at over 85% of the sites used in the study, at both the calibration and evaluation stages. The new improved parameters for JULES are presented along with the associated uncertainties for each parameter.This work was supported by the UK Natural Environment Research Council (NERC) through the National Centre for Earth Observation (NCEO). This study used eddy-covariance data acquired by the FLUXNET community and in particular by the following networks: AmeriFlux (US Department of Energy, Biological and Environmental Research, Terrestrial Carbon Program (DE-FG02-04ER63917 and DE-FG02-04ER63911)), AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada (supported by CFCAS, NSERC, BIOCAP, Environment Canada, and NRCan), GreenGrass, KoFlux, LBA, NECC, OzFlux, TCOSSiberia, USCCC. Support for eddy-covariance data harmonisation was provided by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, Université Laval and Environment Canada and US Department of Energy and the database development and technical support from Berkeley Water Center, Lawrence Berkeley National Laboratory, Microsoft Research eScience, Oak Ridge National Laboratory, University of California – Berkeley, University of Virginia. The authors are grateful to T. Kaminski and R. Giering from FastOpt for their contribution to the development of the adjoint model, and to M. Groenendijk, A. Harper, and the UK Met Office for processing and sharing their data. The authors are particularly grateful to two anonymous referees for their thoughtful and constructive reviews, which greatly improved this manuscript

Multidetector CT Improving Surgical Outcomes in Breast Cancer (MISO BC)

Introduction: This multicentre randomised controlled trial investigated whether a computed tomography (CT) scan of the axilla could more accurately assess whether the axillary lymph nodes were involved with malignancy in patients with newly diagnosed breast cancer and therefore influence surgical decision-making with regard to axillary surgery. Methods: Patients with newly diagnosed breast cancer (via screening and symptomatic routes) at two NHS Trusts in the North East of England were recruited and randomised in equal numbers. Both groups received routine diagnostic and surgical care (usual care). In addition, one group received a CT scan of their axilla on the same side as the breast cancer. Results: The study recruited 297 patients, of whom 291 contributed to findings. CT scan-guided care did not result in a change in the need for a second operation, with about 20% of both groups needing further surgery. Patients within the two groups were similar before treatment, had similar types and grade of cancer, experienced similar pattern complications and reported similar experiences of care. Conclusion: New diagnostic imaging technologies regularly enter NHS centres of excellence as research tools. It is important these are evaluated rigorously before becoming routine care. In patients newly diagnosed with breast cancer, CT-augmented diagnosis of cancer in the axilla was not found to improve surgical outcomes or patient experience

Assessing trade-offs in large marine protected areas

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data of coded case-studies can be viewed at: https://sesmad.dartmouth.edu/ses_casesLarge marine protected areas (LMPAs) are increasingly being established and have a high profile in marine conservation. LMPAs are expected to achieve multiple objectives, and because of their size are postulated to avoid trade-offs that are common in smaller MPAs. However, evaluations across multiple outcomes are lacking. We used a systematic approach to code several social and ecological outcomes of 12 LMPAs. We found evidence of three types of trade-offs: trade-offs between different ecological resources (supply trade-offs); trade-offs between ecological resource conditions and the well-being of resource users (supply-demand trade-offs); and trade-offs between the well-being outcomes of different resource users (demand trade-offs). We also found several divergent outcomes that were attributed to influences beyond the scope of the LMPA. We suggest that despite their size, trade-offs can develop in LMPAs and should be considered in planning and design. LMPAs may improve their performance across multiple social and ecological objectives if integrated with larger-scale conservation efforts.Social Science and Humanities Research Council of CanadaNatural Sciences and Engineering Research Council of Canad

The preferences of 600 patients for different descriptions of randomisation

A total of 600 patients from cancer centres throughout the UK identified their most preferred and most disliked descriptions of randomisation found in current patient information sheets and websites. The CancerBACUP description, which describes both the process of randomisation and why it is done, was most preferred 151 out of 533 (28%) patients. The NCI description was viewed as overly technical and most disliked 185 out of 483 (38%) patients

Far-infrared spectroscopic images of M83

We have mapped the nearby face on barred spiral galaxy, M83 in the bright [CII] 158 μm, [OI] 63 and 146 μm, [NII] 122 μm, and [OIII] 88 μm fine-structure lines with the Long Wavelength Spectrometer (LWS) on ISO. The maps are nearly fully sampled, and cover the inner 6.75' x 6' region - essentially the entire optical disk. We also obtained a full LWS grating scan of the nucleus. The lines are detectable over the entire disk, and enhanced at the nucleus, where the [OI] 63 μm and [NII] lines are particularly strong. At the nucleus, the line ratios indicate a strong starburst headed by O9 stars. Surprisingly, the [OI] and [CII] line emission (from photodissociation regions) is not enhanced relative to [NII] (from low density HII regions) on the spiral arms. The line ratios are the same for the spiral arms and interarm regions. We find very strong emission in the [OIII] 88 μm, [OI] 146 μm, and [CII] lines at the intersection of the bar and spiral arm to the SW indicating particularly strong star formation activity there. The [OI] 63 μm/146 μm line ratio is quite small there likely the result of self absorption in the 63 μm line by enveloping clouds. The total luminosity of this emission peak is 1.2 x 109 Lodo

Unsupervised Bayesian linear unmixing of gene expression microarrays

Background: This paper introduces a new constrained model and the corresponding algorithm, called unsupervised Bayesian linear unmixing (uBLU), to identify biological signatures from high dimensional assays like gene expression microarrays. The basis for uBLU is a Bayesian model for the data samples which are represented as an additive mixture of random positive gene signatures, called factors, with random positive mixing coefficients, called factor scores, that specify the relative contribution of each signature to a specific sample. The particularity of the proposed method is that uBLU constrains the factor loadings to be non-negative and the factor scores to be probability distributions over the factors. Furthermore, it also provides estimates of the number of factors. A Gibbs sampling strategy is adopted here to generate random samples according to the posterior distribution of the factors, factor scores, and number of factors. These samples are then used to estimate all the unknown parameters. Results: Firstly, the proposed uBLU method is applied to several simulated datasets with known ground truth and compared with previous factor decomposition methods, such as principal component analysis (PCA), non negative matrix factorization (NMF), Bayesian factor regression modeling (BFRM), and the gradient-based algorithm for general matrix factorization (GB-GMF). Secondly, we illustrate the application of uBLU on a real time-evolving gene expression dataset from a recent viral challenge study in which individuals have been inoculated with influenza A/H3N2/Wisconsin. We show that the uBLU method significantly outperforms the other methods on the simulated and real data sets considered here. Conclusions: The results obtained on synthetic and real data illustrate the accuracy of the proposed uBLU method when compared to other factor decomposition methods from the literature (PCA, NMF, BFRM, and GB-GMF). The uBLU method identifies an inflammatory component closely associated with clinical symptom scores collected during the study. Using a constrained model allows recovery of all the inflammatory genes in a single factor