402 research outputs found
Shear Strength as a Measure of Soil Consistency
Agronomic soil consistency terms have been evaluated using shear strength as a unit of measure. The Torvane vane shear strength device was employed to measure shear strength on pedogenic profiles developed in several parent materials and on unconsolidated substratas of till. Correlations were then established between the consistency class and shear strength. The shear device is capable of placing a numerical value on soil consistency classes. Variations in consistency were controlled by soil structure, bulk density, texture and organic matter. The device can easily be carried in the field and can reduce bias in the investigator\u27s consistency estimations
Optimal -type relaxation rates for the Cahn-Hilliard equation on the line
In this paper we derive optimal algebraic-in-time relaxation rates to the
kink for the Cahn-Hilliard equation on the line. We assume that the initial
data have a finite distance---in terms of either a first moment or the excess
mass---to a kink profile and capture the decay rate of the energy and the
perturbation. Our tools include Nash-type inequalities, duality arguments, and
Schauder estimates
Screening of healthcare workers for tuberculosis: development and validation of a new health economic model to inform practice
Methods for determining cost-effectiveness of different treatments are well established, unlike appraisal of non-drug interventions, including novel diagnostics and biomarkers
Low-Frequency Noise Characterization of Ultra-shallow Gate N-channel Junction Field Effect Transistors
A recently developed technique for ultra shallow pn junction formation has been applied for the fabrication of ring-gate n-channel junction field effect devices (JFET) devices. Several different geometries, gate formation parameters and channel doping profiles have been realized and characterized with respect to I-V and C-V characteristics both on wafer and after packaging. Low-frequency noise measurements have been performed on packaged devices by mean of a cross-correlation scheme. Data have been compared both with that of similar devices fabricated in a standard process and with simulations results. The devices show good DC performance, and the transconductance values achieved, with respect of the channel dimensions, are notably high. No G-R noise was detected, but the devices yielded a high flicker noise component. This phenomenon is shown to be neither correlated to the device area nor to incidental trapping levels at the junction interface. It is therefore assumed that perimeter effects are decisive for the enhancement of the 1/f spectrum
From Relational Data to Graphs: Inferring Significant Links using Generalized Hypergeometric Ensembles
The inference of network topologies from relational data is an important
problem in data analysis. Exemplary applications include the reconstruction of
social ties from data on human interactions, the inference of gene
co-expression networks from DNA microarray data, or the learning of semantic
relationships based on co-occurrences of words in documents. Solving these
problems requires techniques to infer significant links in noisy relational
data. In this short paper, we propose a new statistical modeling framework to
address this challenge. It builds on generalized hypergeometric ensembles, a
class of generative stochastic models that give rise to analytically tractable
probability spaces of directed, multi-edge graphs. We show how this framework
can be used to assess the significance of links in noisy relational data. We
illustrate our method in two data sets capturing spatio-temporal proximity
relations between actors in a social system. The results show that our
analytical framework provides a new approach to infer significant links from
relational data, with interesting perspectives for the mining of data on social
systems.Comment: 10 pages, 8 figures, accepted at SocInfo201
Spasticity of the gastrosoleus muscle is related to the development of reduced passive dorsiflexion of the ankle in children with cerebral palsy: A registry analysis of 2,796 examinations in 355 children
Background and purpose Spasticity and muscle contracture are two common manifestations of cerebral palsy (CP). A spastic muscle may inhibit growth in length of the muscle, but the importance of this relationship is not known. In 1994, a register and a healthcare program for children with CP in southern Sweden were initiated. The child's muscle tone according to the Ashworth scale and the ankle range of motion (ROM) is measured annually during the entire growth period. We have used these data to analyze the relationship between spasticity and ROM of the gastrosoleus muscle. Patients and methods All measurements in the total population of children with CP aged 0-18 years during the period January 1995 through June 2008 were analyzed. The study was based on 2,796 examinations in 355 children. In the statistical analysis, the effect of muscle tone on ROM was estimated using a random effects model. Results The range of dorsiflexion of the ankle joint decreased in the total material by mean 19 (95% CI: 14-24) degrees during the first 18 years of life. There was a statistically significant association between the ROM and the child's level of spasticity during the year preceding the ROM measurement. Interpretation Spasticity is related to the development of muscle contracture. In the treatment of children with CP, the spasticity, contracture, and strength of the gastrosoleus muscle must be considered together
A systematic review of the use of an expertise-based randomised controlled trial design
Acknowledgements JAC held a Medical Research Council UK methodology (G1002292) fellowship, which supported this research. The Health Services Research Unit, Institute of Applied Health Sciences (University of Aberdeen), is core-funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. Views express are those of the authors and do not necessarily reflect the views of the funders.Peer reviewedPublisher PD
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