2,568 research outputs found
Clinical decision support using machine learning and cardiac troponin for the diagnosis of myocardial infarction
Measurement of persistence in 1-D diffusion
Using a novel NMR scheme we observed persistence in 1-D gas diffusion. Analytical approximations and numerical simulations have shown that for an initially random array of spins undergoing diffusion, the probability p(t) that the average spin orientation in a given region has not changed sign (i.e., ``persists'') up to time t follows a power law t^{-\theta}, where \theta depends on the dimensionality of the system. The large nuclear spin polarization of laser-polarized 129Xe gas allowed us both to prepare an initial ``quasi-random'' 1-D array of spin orientations and then to perform real-time NMR imaging to monitor the spin diffusion. Our measurements are consistent with theoretical and numerical predictions of \theta ~ 0.12. We also observed finite size effects for long time gas diffusion
Maximum-likelihood absorption tomography
Maximum-likelihood methods are applied to the problem of absorption
tomography. The reconstruction is done with the help of an iterative algorithm.
We show how the statistics of the illuminating beam can be incorporated into
the reconstruction. The proposed reconstruction method can be considered as a
useful alternative in the extreme cases where the standard ill-posed
direct-inversion methods fail.Comment: 7 pages, 5 figure
Entanglement of photons
It is argued that the title of this paper represents a misconception.
Contrary to widespread beliefs it is electromagnetic field modes that are
``systems'' and can be entangled, not photons. The amount of entanglement in a
given state is shown to depend on redefinitions of the modes; we calculate the
minimum and maximum over all such redefinitions for several examples.Comment: 5 pages ReVTe
Glucose concentration in capillary blood of dairy cows obtained by a minimally invasive lancet technique and determined with three different hand-held devices
Background Dairy cows have a massive demand for glucose at the onset of
lactation. A poor adaption to this period leads to an excessive negative
energy balance with an increased risk for ketosis and impaired animal health
and production. Besides the measurement of ketones, analysing the glucose
concentration in blood is reported as helpful instrument for diagnosis and
differentiation of ketosis. Monitoring metabolic parameters requires multiple
blood sampling. In other species, new blood sampling techniques have been
introduced in which small amounts of blood are rapidly analysed using
electronic hand-held devices. The objective of this study was to evaluate the
suitability of capillary blood for blood glucose measurement in dairy cows
using the hand-held devices FreeStyle Precision (FSP, Abbott), GlucoMen LX
Plus (GLX, A. Menarini) and the WellionVet GLUCO CALEA, (WGC, MED TRUST). In
total, 240 capillary blood samples were obtained from dry and fresh lactating
Holstein-Friesian cows. Blood was collected from the skin of the exterior
vulva by using a lancet. For method comparison, additional blood samples were
taken from a coccygeal vessel and analyzed in a laboratory. Glucose
concentrations measured by a standard laboratory method were defined as the
criterion standard. Results The Pearson correlation coefficients between the
glucose concentrations analyzed in capillary blood with the devices and the
reference were 73 % for the FSP, 81 % for the GLX and 41 % for the WGC. Bland-
Altman plots showed biases of â18.8 mg/dL for the FSP, -11.2 mg/dL for the GLX
and +20.82 mg/dL for the WGC. The optimized threshold determined by a Receiver
Operating Characteristics analysis to detect hyperglycemia using the FSP was
43 mg/dL with a sensitivity (Se) and specificity (Sp) of 76 and 80 %. Using
the GLX and WGC optimized thresholds were 49 mg/dL (Seâ=â92 %, Spâ=â85 %) and
95 mg/dL (Seâ=â39 %, Spâ=â92 %). Conclusions The results of this study
demonstrate good performance characteristics for the GLX and moderate for the
FSP to detect hyperglycemia in dairy cows using capillary blood. With the
study settings, the WGC was not suitable for determination of glucose
concentrations
Measuring surface-area-to-volume ratios in soft porous materials using laser-polarized xenon interphase exchange NMR
We demonstrate a minimally invasive nuclear magnetic resonance (NMR)
technique that enables determination of the surface-area-to-volume ratio (S/V)
of soft porous materials from measurements of the diffusive exchange of
laser-polarized 129Xe between gas in the pore space and 129Xe dissolved in the
solid phase. We apply this NMR technique to porous polymer samples and find
approximate agreement with destructive stereological measurements of S/V
obtained with optical confocal microscopy. Potential applications of
laser-polarized xenon interphase exchange NMR include measurements of in vivo
lung function in humans and characterization of gas chromatography columns.Comment: 14 pages of text, 4 figure
Improving the normalization of complex interventions: measure development based on normalization process theory (NoMAD): study protocol
<b>Background</b> Understanding implementation processes is key to ensuring that complex interventions in healthcare are taken up in practice and thus maximize intended benefits for service provision and (ultimately) care to patients. Normalization Process Theory (NPT) provides a framework for understanding how a new intervention becomes part of normal practice. This study aims to develop and validate simple generic tools derived from NPT, to be used to improve the implementation of complex healthcare interventions.<p></p>
<b>Objectives</b> The objectives of this study are to: develop a set of NPT-based measures and formatively evaluate their use for identifying implementation problems and monitoring progress; conduct preliminary evaluation of these measures across a range of interventions and contexts, and identify factors that affect this process; explore the utility of these measures for predicting outcomes; and develop an online usersâ manual for the measures.<p></p>
<b>Methods</b> A combination of qualitative (workshops, item development, user feedback, cognitive interviews) and quantitative (survey) methods will be used to develop NPT measures, and test the utility of the measures in six healthcare intervention settings.<p></p>
<b>Discussion</b> The measures developed in the study will be available for use by those involved in planning, implementing, and evaluating complex interventions in healthcare and have the potential to enhance the chances of their implementation, leading to sustained changes in working practices
Turning round the telescope. Centre-right parties and immigration and integration policy in Europe
This is an Author's Original Manuscript of 'Turning round the telescope. Centre-right parties and immigration and integration policy in Europe', whose final and definitive form, the Version of Record, has been published in the Journal of European Public Policy 15(3):315-330, 2008 [copyright Taylor & Francis], available online at: http://www.tandfonline.com/doi.org/10.1080/13501760701847341
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