6,449 research outputs found

    Effect of a rigid ankle-foot orthosis on hamstring length in children with hemiplagia

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    Eighteen children with hemiplegia, mean age 8 years 5 months, underwent gait analysis and musculoskeletal modelling using specially designed software. The maximum lengths of the hamstrings were determined for each child walking in and out of an ankle–foot orthosis (AFO). The muscles were deemed to be short if shorter than the normal average – 1SD. In bare feet 8 participants had short medial hamstrings with a higher proportion of these in the less involved individuals. All participants showed an increase in maximum hamstring length when wearing an AFO. In all but one child this was sufficient to restore hamstring length to within normal limits. These finding suggest that hamstring pathology in hemiplegic gait is usually secondary to more distal lower limb pathology

    Labour and Diversification. An Efficiency Analysis of Cattle and Sheep Farms in Scotland

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    This analysis uses FADN data and Data Envelopment Analysis to estimate how efficient Scottish cattle and sheep farms are in their use of labour to deliver diversification outputs. Results show a strong difference between how efficiently paid and unpaid labour are used for creation of both diversification and livestock outputs, with unpaid labour scores consistently higher than paid labour scores. The efficiency of unpaid labour in creation of traditional livestock products as compared to diversification is, as expected, lower. Both paid and unpaid labour are more efficiently used on sheep farms than cattle farms to produce livestock outputs. It is less surprising that, compared to all other inputs, the use of unpaid labour is the most efficient for creation of diversification outputs, than it is the fact that unpaid labour is still highly efficient for creation of traditional livestock products, e.g., higher than land area and paid labour

    Labour and Diversification. An Efficiency Analysis of Cattle and Sheep Farms in Scotland

    Get PDF
    This analysis uses FADN data and Data Envelopment Analysis to estimate how efficient Scottish cattle and sheep farms are in their use of labour to deliver diversification outputs. Results show a strong difference between how efficiently paid and unpaid labour are used for creation of both diversification and livestock outputs, with unpaid labour scores consistently higher than paid labour scores. The efficiency of unpaid labour in creation of traditional livestock products as compared to diversification is, as expected, lower. Both paid and unpaid labour are more efficiently used on sheep farms than cattle farms to produce livestock outputs. It is less surprising that, compared to all other inputs, the use of unpaid labour is the most efficient for creation of diversification outputs, than it is the fact that unpaid labour is still highly efficient for creation of traditional livestock products, e.g., higher than land area and paid labour

    An economic assessment of ecological practices in Scotland

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    An early adoption of ecological management practices by farmers is a potential route to achieve sustainable and greener goals for agriculture. This briefing note outlines an economic assessment of four different ecological practices on Scottish livestock farms. The ecological practices used are; ecological area, reducing farm inputs, organic adoption and agro-forestry. The results suggest that ecological area and reduced farm inputs have potential financial benefits on farms and can be easily adopted by farmers. The organic and agro-forestry systems, however, require capital investment to establish and hence provide a challenging prospect of adoption without a provision of financial support<br/

    A Method for Serial Tissue Processing and Parallel Analysis of Aberrant Crypt Morphology, Mucin Depletion, and Beta-Catenin Staining in an Experimental Model of Colon Carcinogenesis

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    The use of architectural and morphological characteristics of cells for establishing prognostic indicators by which individual pathologies are assigned grade and stage is a well-accepted practice. Advances in automated micro- and macroscopic image acquisition and digital image analysis have created new opportunities in the field of prognostic assessment; but, one area in experimental pathology, animal models for colon cancer, has not taken advantage of these opportunities. This situation is primarily due to the methods available to evaluate the colon of the rodent for the presence of premalignant and malignant pathologies. We report a new method for the excision and processing of the entire colon of the rat and illustrate how this procedure permitted the quantitative assessment of aberrant crypt foci (ACF), a premalignant colon pathology, for characteristics consistent with progression to malignancy. ACF were detected by methylene blue staining and subjected to quantitative morphometric analysis. Colons were then restained with high iron diamine–alcian blue for assessment of mucin depletion using an image overlay to associate morphometric data with mucin depletion. The subsequent evaluation of ACF for beta-catenin staining is also demonstrated. The methods described are particularly relevant to the screening of compounds for cancer chemopreventive activity

    Building nonparametric nn-body force fields using Gaussian process regression

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    Constructing a classical potential suited to simulate a given atomic system is a remarkably difficult task. This chapter presents a framework under which this problem can be tackled, based on the Bayesian construction of nonparametric force fields of a given order using Gaussian process (GP) priors. The formalism of GP regression is first reviewed, particularly in relation to its application in learning local atomic energies and forces. For accurate regression it is fundamental to incorporate prior knowledge into the GP kernel function. To this end, this chapter details how properties of smoothness, invariance and interaction order of a force field can be encoded into corresponding kernel properties. A range of kernels is then proposed, possessing all the required properties and an adjustable parameter nn governing the interaction order modelled. The order nn best suited to describe a given system can be found automatically within the Bayesian framework by maximisation of the marginal likelihood. The procedure is first tested on a toy model of known interaction and later applied to two real materials described at the DFT level of accuracy. The models automatically selected for the two materials were found to be in agreement with physical intuition. More in general, it was found that lower order (simpler) models should be chosen when the data are not sufficient to resolve more complex interactions. Low nn GPs can be further sped up by orders of magnitude by constructing the corresponding tabulated force field, here named "MFF".Comment: 31 pages, 11 figures, book chapte

    Machine-learning of atomic-scale properties based on physical principles

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    We briefly summarize the kernel regression approach, as used recently in materials modelling, to fitting functions, particularly potential energy surfaces, and highlight how the linear algebra framework can be used to both predict and train from linear functionals of the potential energy, such as the total energy and atomic forces. We then give a detailed account of the Smooth Overlap of Atomic Positions (SOAP) representation and kernel, showing how it arises from an abstract representation of smooth atomic densities, and how it is related to several popular density-based representations of atomic structure. We also discuss recent generalisations that allow fine control of correlations between different atomic species, prediction and fitting of tensorial properties, and also how to construct structural kernels---applicable to comparing entire molecules or periodic systems---that go beyond an additive combination of local environments

    Non-abelian T-duality, Ramond Fields and Coset Geometries

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    We extend previous work on non-abelian T-duality in the presence of Ramond fluxes to cases in which the duality group acts with isotropy such as in backgrounds containing coset spaces. In the process we generate new supergravity solutions related to D-brane configurations and to standard supergravity compactifications.Comment: 35 pages, Late
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