Analysis and compensation for errors in electrical impedance tomography images and ventilation-­related measures due to serial data collection

Electrical impedance tomography (EIT) is increasingly being used as a bedside tool for monitoring regional lung ventilation. However, most clinical systems use serial data collection which, if uncorrected, results in image distortion, particularly at high breathing rates. The objective of this study was to determine the extent to which this affects derived parameters. Raw EIT data were acquired with the GOE­MF II EIT device (CareFusion, Höchberg, Germany) at a scan rate of 13 images/s during both spontaneous breathing and mechanical ventilation. Boundary data for periods of undisturbed tidal breathing were corrected for serial data collection errors using a Fourier based algorithm. Images were reconstructed for both the corrected and original data using the GREIT algorithm, and parameters describing the filling characteristics of the right and left lung derived on a breath by breath basis. Values from the original and corrected data were compared using paired t­ tests. Of the 33 data sets, 23 showed significant differences in filling index for at least one region, 11 had significant differences in calculated tidal impedance change and 12 had significantly different filling fractions (p = 0.05). We conclude that serial collection errors should be corrected before image reconstruction to avoid clinically misleading results

Adaptation of an evidence-based cardiovascular health intervention for rural African Americans in the Southeast

Background: African Americans (AA) living in the southeast United States have the highest prevalence of cardiovascular diseases (CVD) and rural minorities bear a significant burden of co-occurring CVD risk factors. Few evidence-based interventions (EBI) address social and physical environmental barriers in rural minority communities. We used intervention mapping together with community-based participatory research (CBPR) principles to adapt objectives of a multi-component CVD lifestyle EBI to fit the needs of a rural AA community. We sought to describe the process of using CPBR to adapt an EBI using intervention mapping to an AA rural setting and to identify and document the adaptations mapped onto the EBI and how they enhance the intervention to meet community needs. Methods: Focus groups, dyadic interviews, and organizational web-based surveys were used to assess content interest, retention strategies, and incorporation of auxiliary components to the EBI. Using CBPR principles, community and academic stakeholders met weekly to collaboratively integrate formative research findings into the intervention mapping process. We used a framework developed by Wilstey Stirman et al. to document changes. Results: Key changes were made to the content, context, and training and evaluation components of the existing EBI. A matrix including behavioral objectives from the original EBI and new objectives was developed. Categories of objectives included physical activity, nutrition, alcohol, and tobacco divided into three levels, namely, individual, interpersonal, and environmental. Conclusions: Intervention mapping integrated with principles of CBPR is an efficient and flexible process for adapting a comprehensive and culturally appropriate lifestyle EBI for a rural AA community context

A direct D-bar reconstruction algorithm for recovering a complex conductivity in 2-D

A direct reconstruction algorithm for complex conductivities in $W^{2,\infty}(\Omega)$, where $\Omega$ is a bounded, simply connected Lipschitz domain in $\mathbb{R}^2$, is presented. The framework is based on the uniqueness proof by Francini [Inverse Problems 20 2000], but equations relating the Dirichlet-to-Neumann to the scattering transform and the exponentially growing solutions are not present in that work, and are derived here. The algorithm constitutes the first D-bar method for the reconstruction of conductivities and permittivities in two dimensions. Reconstructions of numerically simulated chest phantoms with discontinuities at the organ boundaries are included.Comment: This is an author-created, un-copyedited version of an article accepted for publication in [insert name of journal]. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/0266-5611/28/9/09500

Effect of the measurement on the decay rate of a quantum system

We investigated the electron tunneling out of a quantum dot in the presence of a continuous monitoring by a detector. It is shown that the Schr\"odinger equation for the whole system can be reduced to new Bloch-type rate equations describing the time-development of the detector and the measured system at once. Using these equations we find that the continuous measurement of the unstable system does not affect its exponential decay, $\exp (-\Gamma t)$, contrary to expectations based on the Quantum Zeno effect . However, the width of the energy distribution of the tunneling electron is no more $\Gamma$, but increases due to the decoherence, generated by the detector.Comment: Additional explanations are added. Accepted for publications in Phys. Rev. Let

Real clocks and the Zeno effect

Real clocks are not perfect. This must have an effect in our predictions for the behaviour of a quantum system, an effect for which we present a unified description encompassing several previous proposals. We study the relevance of clock errors in the Zeno effect, and find that generically no Zeno effect can be present (in such a way that there is no contradiction with currently available experimental data). We further observe that, within the class of stochasticities in time addressed here, there is no modification in emission lineshapes.Comment: 12 a4 pages, no figure

Zeno and anti-Zeno effects for photon polarization dephasing

We discuss a simple, experimentally feasible scheme, which elucidates the principles of controlling ("engineering") the reservoir spectrum and the spectral broadening incurred by repeated measurements. This control can yield either the inhibition (Zeno effect) or the acceleration (anti-Zeno effect) of the quasi-exponential decay of the observed state by means of frequent measurements. In the discussed scheme, a photon is bouncing back and forth between two perfect mirrors, each time passing a polarization rotator. The horizontal and vertical polarizations can be viewed as analogs of an excited and a ground state of a two level system (TLS). A polarization beam splitter and an absorber for the vertically polarized photon are inserted between the mirrors, and effect measurements of the polarization. The polarization angle acquired in the electrooptic polarization rotator can fluctuate randomly, e.g., via noisy modulation. In the absence of an absorber the polarization randomization corresponds to TLS decay into an infinite-temperature reservoir. The non-Markovian nature of the decay stems from the many round-trips required for the randomization. We consider the influence of the polarization measurements by the absorber on this non-Markovian decay, and develop a theory of the Zeno and anti-Zeno effects in this system.Comment: 11 pages, 4 figure

A Case Study in Maritime Boundary Delimitation: The Gulf of Maine Dispute

The Gulf of Maine area, including Georges Bank, has long been regarded as an area of special interest and importance to United States\u27 fishermen. The riches of Georges Bank were known to New England fishermen in the 18th century, and early in the 19th century, fishermen from Gloucester, Massachusetts developed the halibut fishery on the Bank. Through the 19th century and util the 1950\u27s the Georges Bank fishery was exclusively the province of new England fishermen. However, in the 1960\u27s large factory fleets from the Soviet Union and Japan began to invade the waters of Georges Bank. The wave of newcomers also included Canadian fishermen who, as a result of government subsidies, were able to under-sell U.S. fishermen in American markets. These developments led the United States to join the growing number of coastal nations that were extending their fisheries jurisdiction out to 200 nautical miles

Demonstration of quantum Zeno effect in a superconducting phase qubit

Quantum Zeno effect is a significant tool in quantum manipulating and computing. We propose its observation in superconducting phase qubit with two experimentally feasible measurement schemes. The conventional measurement method is used to achieve the proposed pulse and continuous readout of the qubit state, which are analyzed by projection assumption and Monte Carlo wave-function simulation, respectively. Our scheme gives a direct implementation of quantum Zeno effect in a superconducting phase qubit.Comment: 5 pages, 4 figure

Computer graphics simulation of natural mummification by desiccation

© 2020 The Authors. Computer Animation and Virtual Worlds published by John Wiley & Sons, Ltd. Organic bodies are subject to internal processes after death, causing significant structural, and optical changes. Mummification by desiccation leads to volume shrinkage, skin wrinkling, and discoloration. We propose a method to simulate the process of mummification by desiccation and its effects on the corpse's morphology and appearance. The mummifying body is represented by a layered model consisting of a tetrahedral mesh, representing the volume, plus a high resolution triangle surface mesh representing the skin. The finite element method is used to solve the moisture diffusion and the resulting volume deformations. Skin wrinkling is achieved using position based dynamics. In order to model a visually believable reproduction of the skin coloration changes due to mummification, a skin shading approach is used that considers moisture content, hemoglobin content, and oxygen saturation. The main focus of the work in this article is to recreate the appearance changes of mummification by desiccation, which, to the best of our knowledge, has not been attempted before in computer graphics to this level of realism. The suggested approach is able to model changes in the internal structure and the surface appearance of the body which resemble the postmortem processes of natural mummification by desiccation