160 research outputs found

    Understanding the Process of Fascial Unwinding

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    Fascial or myofascial unwinding is a manual therapy in which a therapist encourages a client’s body to move into areas of ease. It typically involves the client undergoing an induction procedure and this is usually followed by a spontaneous reaction. This paper proposes a model that builds upon the neurobiological, ideomotor action, and consciousness theories to explain the process and mechanism of fascial unwinding. During fascial unwinding, the therapist stimulates mechanoreceptors in the fascia by applying gentle touch and stretching. Touch and stretching induce relaxation and activate the parasympathetic nervous system. It also activates the central nervous system, which is involved in the modulation of muscle tone as well as movement. As a result, the central nervous system is aroused and thereby responds by encouraging muscles to find an easier, or more relaxed position, and by introducing the ideomotor action. Although the ideomotor action is generated via normal voluntary motor control systems, it is altered and experienced as an involuntary response. Consequently, fascial unwinding can be thought of as a neurobiological process employing the self-regulation dynamic system theory

    Efficient Methods for Predicting Soil Hydraulic Properties

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    Both empirical and process-simulation models are useful for evaluating the effects of management practices on environmental quality and crop yield. The use of these models is limited, however, because they need many soil property values as input. The first step towards modelling is the collection of input data. Soil properties can be highly variable spatially and temporally, and measuring them is time-consuming and expensive. Efficient methods, which consider the uncertainty and cost of measurements, for estimating soil hydraulic properties form the main thrust of this study. Hydraulic properties are affected by other soil physical, and chemical properties, therefore it is possible to develop empirical relations to predict them. This idea quantified is called a pedotransfer function. Such functions may be global or restricted to a country or region. The different classification of particle-size fractions used in Australia compared with other countries presents a problem for the immediate adoption of exotic pedotransfer functions. A database of Australian soil hydraulic properties has been compiled. Pedotransfer functions for estimating water-retention and saturated hydraulic conductivity from particle size and bulk density for Australian soil are presented. Different approaches for deriving hydraulic transfer functions have been presented and compared. Published pedotransfer functions were also evaluated, generally they provide a satisfactory estimation of water retention and saturated hydraulic conductivity depending on the spatial scale and accuracy of prediction. Several pedotransfer functions were developed in this study to predict water retention and hydraulic conductivity. The pedotransfer functions developed here may predict adequately in large areas but for site-specific applications local calibration is needed. There is much uncertainty in the input data, and consequently the transfer functions can produce varied outputs. Uncertainty analysis is therefore needed. A general approach to quantifying uncertainty is to use Monte Carlo methods. By sampling repeatedly from the assumed probability distributions of the input variables and evaluating the response of the model the statistical distribution of the outputs can be estimated. A modified Latin hypercube method is presented for sampling joint multivariate probability distributions. This method is applied to quantify the uncertainties in pedotransfer functions of soil hydraulic properties. Hydraulic properties predicted using pedotransfer functions developed in this study are also used in a field soil-water model to analyze the uncertainties in the prediction of dynamic soil-water regimes. The use of the disc permeameter in the field conventionally requires the placement of a layer of sand in order to provide good contact between the soil surface and disc supply membrane. The effect of sand on water infiltration into the soil and on the estimate of sorptivity was investigated. A numerical study and a field experiment on heavy clay were conducted. Placement of sand significantly increased the cumulative infiltration but showed small differences in the infiltration rate. Estimation of sorptivity based on the Philip's two term algebraic model using different methods was also examined. The field experiment revealed that the error in infiltration measurement was proportional to the cumulative infiltration curve. Infiltration without placement of sand was considerably smaller because of the poor contact between the disc and soil surface. An inverse method for predicting soil hydraulic parameters from disc permeameter data has been developed. A numerical study showed that the inverse method is quite robust in identifying the hydraulic parameters. However application to field data showed that the estimated water retention curve is generally smaller than the one obtained in laboratory measurements. Nevertheless the estimated near-saturated hydraulic conductivity matched the analytical solution quite well. Th author believes that the inverse method can give a reasonable estimate of soil hydraulic parameters. Some experimental and theoretical problems were identified and discussed. A formal analysis was carried out to evaluate the efficiency of the different methods in predicting water retention and hydraulic conductivity. The analysis identified the contribution of individual source of measurement errors to the overall uncertainty. For single measurements, the inverse disc-permeameter analysis is economically more efficient than using pedotransfer functions or measuring hydraulic properties in the laboratory. However, given the large amount of spatial variation of soil hydraulic properties it is perhaps not surprising that lots of cheap and imprecise measurements, e.g. by hand texturing, are more efficient than a few expensive precise ones

    PREDICTION OF THE WATER CONTENT AT FIELD CAPACITY FROM DISTURBED SOIL SAMPLES

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    Abstract In many soil databases, water content at -10 kPa was measured on disturbed soil samples. Meanwhile water content at -10 kPa is heavily influenced by soil structure, pore size distribution and bulk density. In this paper a model is developed to preflict water content at field capacity given data obtained from disturbed soil samples. The linear mode/\u27predicts the reduction in water content at field capacity with\u27increasing bulk density and sand content The model has a good fit and was validated against an independent dataset Keywords: pedotransfer functions, available water capacity, soil hydraulic properties, water retention curve, bulk densit

    Entering the digital world (Pedometrics 2009)

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    Development in pedometrics has not only shaped the research agenda in soil science but also attracted the attention of practitioners from other communities such as environmental modelling and land management who require digital information on soils. At the same time, demands from these communities and developments in information technology help to fuel and drive the research agenda of pedometrics. These factors have combined to draw scientists with diverse backgrounds and interests into the field of pedometrics over its short history as a distinctive subdiscipline of soil science
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