The Battlefield and Beyond: Essays on the American Civil War

Fresh Perspectives on Civil War Study Placing Jefferson Davis and George Gershwin in the same volume on the Civil War is not a task for the faint of heart. But then, assembling a celebratory work offers an editor the latitude not always available to the author of a monograph. Clayt...

Review Essays--Henry Clay and the Historian: A One-Hundred-Year Perspective

Asked on his deathbed if he had any regrets of things that he had not done in his life, Andrew Jackson replied, “Yes, I didn’t shoot Henry Clay and I didn’t hang John C. Calhoun.” Jackson viewed Clay as a “base, mean scoundrel,” while Clay judged Old Hickory to be an ignorant, corrupt hypocrite. Although Clay attained an enviable list of public contributions during his lifetime, the enmity between him and Jackson often serves as the focal point of the Kentuckian’s forty-year career. Clay scholars have struggled for over 150 years to bring him out of Jackson’s shadow and into the warm light of recognition of his accomplishments as politician and diplomat

Weighted Least-Squares Finite Element Method for Cardiac Blood Flow Simulation with Echocardiographic Data

As both fluid flow measurement techniques and computer simulation methods continue to improve, there is a growing need for numerical simulation approaches that can assimilate experimental data into the simulation in a flexible and mathematically consistent manner. The problem of interest here is the simulation of blood flow in the left ventricle with the assimilation of experimental data provided by ultrasound imaging of microbubbles in the blood. The weighted least-squares finite element method is used because it allows data to be assimilated in a very flexible manner so that accurate measurements are more closely matched with the numerical solution than less accurate data. This approach is applied to two different test problems: a flexible flap that is displaced by a jet of fluid and blood flow in the porcine left ventricle. By adjusting how closely the simulation matches the experimental data, one can observe potential inaccuracies in the model because the simulation without experimental data differs significantly from the simulation with the data. Additionally, the assimilation of experimental data can help the simulation capture certain small effects that are present in the experiment, but not modeled directly in the simulation

Weighted least-squares finite elements based on Particle Imaging Velocimetry data

Abstract The solution of the Navier-Stokes equations requires that data about the solution is available along the boundary. In some situations, such as particle imaging velocimetry, there is additional data available along a single plane within the domain, and there is a desire to also incorporate this data into the approximate solution of the Navier-Stokes equation. The question that we seek to answer in this paper is whether 2-dimensional velocity data containing noise can be incorporated into a full 3-dimensional solution of the Navier-Stokes equations in an appropriate and meaningful way. For addressing this problem, we examine the potential of least-squares finite element methods (LSFEM) because of their flexibility in the enforcement of various boundary conditions. Further, by weighting the boundary conditions in a manner that properly reflects the accuracy with which the boundary values are known, we develop the weighted LSFEM. The potential of weighted LSFEM is explored for three different test problems: the first uses randomly generated Gaussian noise to create artificial 'experimental' data in a controlled manner, and the second and third use particle imaging velocimetry data. In all test problems, weighted LS-FEM produces accurate results even for cases where there is significant noise in the experimental data

Evaluating Knowledge Anchors in Data Graphs against Basic Level Objects

The growing number of available data graphs in the form of RDF Linked Da-ta enables the development of semantic exploration applications in many domains. Often, the users are not domain experts and are therefore unaware of the complex knowledge structures represented in the data graphs they in-teract with. This hinders users’ experience and effectiveness. Our research concerns intelligent support to facilitate the exploration of data graphs by us-ers who are not domain experts. We propose a new navigation support ap-proach underpinned by the subsumption theory of meaningful learning, which postulates that new concepts are grasped by starting from familiar concepts which serve as knowledge anchors from where links to new knowledge are made. Our earlier work has developed several metrics and the corresponding algorithms for identifying knowledge anchors in data graphs. In this paper, we assess the performance of these algorithms by considering the user perspective and application context. The paper address the challenge of aligning basic level objects that represent familiar concepts in human cog-nitive structures with automatically derived knowledge anchors in data graphs. We present a systematic approach that adapts experimental methods from Cognitive Science to derive basic level objects underpinned by a data graph. This is used to evaluate knowledge anchors in data graphs in two ap-plication domains - semantic browsing (Music) and semantic search (Ca-reers). The evaluation validates the algorithms, which enables their adoption over different domains and application contexts

Ultrasound-Guided Placement of a Renal Artery Stent Using an Intracardiac Probe for Transvascular Imaging

In this set of images obtained during an experimental study using a porcine animal model, we introduce ultrasound guidance of percutaneous transluminal renal angioplasty and renal stenting. A state-of-the-art intracardiac ultrasound catheter is used here for transvascular scanning from within the lumen of the abdominal aorta, thus providing a field of view for navigation of a balloon catheter and a wire coil (“stent”) into each renal artery of a pig. This study is intended as a contribution to the growing field of minimally invasive interventions and their navigation by non-ionizing ultrasound imaging

Pressure and Flow Properties of Cannulae for Extracorporeal Membrane Oxygenation II: Drainage (Venous) Cannulae

The use of extracorporeal life support devices such as extracorporeal membrane oxygenation in adults requires cannulation of the patient's vessels with comparatively large diameter cannulae to allow circulation of large volumes of blood (>5 L/min). The cannula diameter and length are the major determinants for extracorporeal membrane oxygenation flow. Manufacturing companies present pressure-flow charts for the cannulae; however, these tests are performed with water. Aims of this study were 1. to investigate the specified pressure-flow charts obtained when using human blood as the circulating medium and 2. to support extracorporeal membrane oxygenation providers with pressure-flow data for correct choice of the cannula to reach an optimal flow with optimal hydrodynamic performance. Eighteen extracorporeal membrane oxygenation drainage cannulae, donated by the manufacturers (n = 6), were studied in a centrifugal pump driven mock loop. Pressure-flow properties and cannula features were described. The results showed that when blood with a hematocrit of 27% was used, the drainage pressure was consistently higher for a given flow (range 10%-350%) than when water was used (data from each respective manufacturer's product information). It is concluded that the information provided by manufacturers in line with regulatory guidelines does not correspond to clinical performance and therefore may not provide the best guidance for clinicians.info:eu-repo/semantics/publishedVersio