MODEL COMPUTATION WITH SECOND-ORDER RADIATIVE TRANSFER EQUATION FOR SNOW MEDIUM USING COUPLED FINITE ELEMENT METHOD AND METHOD OF MOMENT AND RELAXED HIERARCHICAL EQUIVALENT SOURCE ALGORITHM

Active microwave remote sensing is essential to monitor the conditions of the environment by analyzing the microwave returns from the earth terrain. Various Computational Electromagnetics (CEM) techniques are implemented to study the backscattering coefficient of numerous earth terrains such as vegetation and snow medium. In this paper, a theoretical model based on second order radiative transfer equation is investigated by incorporating two computational methods which are known as coupled Finite Element Method (FEM) and Method of Moment (MoM), and Relaxed Hierarchical Equivalent Source Algorithm (RHESA). These theoretical models consider three shapes of scatterers which can be used to represent the ice particles of snow medium. These mentioned shapes are sphere, droxtal and hexagonal column. These methods are used to investigate the effect of various incident angles and frequencies on the backscattering mechanism. These results are compared with analytical Mie solution and ground truth measurement to analyze and verify the model

Passive Microwave Remote Sensing for Sea Ice Thickness Retrieval Using Neural Network and Genetic Algorithm

Abstract-Over the years, global warming has gained much attention from the global community. The fact that the sea ice plays an important role and has significant effects towards the global climate has prompted scientists to conduct various researches on the sea ice in the Polar Regions. One of the important parameters being studied is the sea ice thickness as it is a direct key indication towards the climate change. However, to conduct studies on the sea ice scientists are often facing with tough challenges due to the unfavorable harsh weather conditions and the remoteness of the Polar Regions. Thus, microwave remote sensing offers an attractive mean for the observation and monitoring of the changes of sea ice in the Polar Regions for the scientists. In this paper, we will be presenting 2 approaches using passive microwave remote sensing to retrieve sea ice thickness. The first approach involves the training and testing of the neural network (NN) by using data sets generated from the Radiative Transfer Theory with Dense Medium Phase and Amplitude Correction Theory (RT-DMPACT) forward scattering model. Once training is completed, the inversion for sea ice thickness could be done speedily. The second approach utilizes a genetic algorithm (GA) which would perform a search routine to identify possible solutions in sea ice thickness that would match the corresponding brightness temperatures profile of the sea ice. The results obtained from both approaches are presented and tested by using Special Scanning Microwave Imager (SSM/I) data with the aid of the sea ice measurements in the Arctic sea

25 Theoretical Modeling and Measurement Comparison of Season-long Rice Field Monitoring

Abstract The development of a theoretical model to describe the scattering mechanisms involved in the remote sensing of rice crops is essential, as it ensures correct application of remote sensing data for rice monitoring. The theoretical model used in this study is based on the radiative transfer theory applied on a layered dense discrete random medium. The dense medium phase and amplitude correction theory (DM-PACT), which considers the coherent effects of the scatterers, is incorporated in the development of the phase matrices of the scatterers, which are modeled after the physical geometry of the plants. Ground truth measurements of rice fields were acquired at Sungai Burung, Selangor, Malaysia for an entire season. These measurements are used in the theoretical model to calculate the backscattering coefficients of rice fields. The results are then compared to those obtained from RADARSAT images to test the validity of the model. Comparisons show promising results, but further research is required to improve on the current model

Electromagnetic Wave Theory and Applications

Contains table of contents for Section 3, reports on three research projects and a list of publications.California Institute of Technology/Jet Propulsion Laboratory Contract 959548National Aeronautics and Space Administration Grant NAGW-1617National Aeronautics and Space Administration Grant Contract 958461U.S. Navy - Office of Naval Research Grant N00014-92-J-1616U.S. Navy - Office of Naval Research Grant N00014-92-J-4098Digital Equipment Corporation AGMT DTD 11/16/93Joint Services Electronics Program Contract DAAL03-92-C-0001Joint Services Electronics Program Grant DAAH04-95-1-0038MIT Lincoln Laboratory P.O. No. BX-5424U.S. Navy - Office of Naval Research Grant N00014-90-J-1002U.S. Navy - Office of Naval Research Grant N00014-89-J-1019DEMACO Agreement 11/15/93Federal Aviation Administration Grant 94-G-007U.S. Army Cold Regions Research and Engineering Laboratory Contract DACA89-93-K-000

Electromagnetic Wave Theory and Applications

Contains table of contents for Section 3 and reports on four research projects.California Institute of Technology/Jet Propulsion Laboratory Agreement 959548National Aeronautics and Space Administration Grant NAGW-1617National Aeronautics and Space Administration Agreement 958461U.S. Navy - Office of Naval Research Grant N00014-89-J-1107U.S. Navy - Office of Naval Research Grant N00014-92-J-1616U.S. Navy - Office of Naval Research Grant N00014-92-J-4098Digital Equipment CorporationJoint Services Electronics Program Contract DAAL03-92-C-0001U.S. Navy - Office of Naval Research Agreement N00014-90-J-1002U.S. Navy - Office of Naval Research Agreement N00014-89-J-1019DEMACOU.S. Army Cold Regions Research and Engineering Laboratory Contract DACA89-93-K-0009U.S. Department of Transportation Agreement DTRS-57-92-C-00054TTD1Advanced Research Projects Agency/Consortium for Superconducting Electronics Contract MDA972-90-C-0021National Science Foundation Fellowship MIP 88-58764National Science Foundatio

Electromagnetic Wave Theory and Applications

Contains table of contents for Section 3, reports on four research projects and a list of publications.National Aeronautics and Space Administration Grant NAGW-1617National Aeronautics and Space Administration Agreement 958461National Aeronautics and Space Administration Grant NAGW-1272U.S. Army Corp of Engineers Contract DACA39-87-K-0022U.S. Navy - Office of Naval Research Grant N00014-89-J-1107U.S. Navy - Office of Naval Research Grant N00014-92-J-1616Digital Equipment CorporationJoint Services Electronics Program Contract DAAL03-92-C-0001U.S. Navy - Office of Naval Research Grant N00014-90-J-1002U.S. Navy - Office of Naval Research Grant N00014-89-J-1019U.S. Department of Transportation Agreement DTRS-57-88-C-00078TTD13U.S. Department of Transportation Agreement DTRS-57-88-C-00078TTD30U.S. Department of Transportation Agreement DTRS-57-92-C-00054TTD1DARPA/Consortium for Superconducting Electronics Contract MDA972-90-C-0021National Science Foundation Fellowship MIP 88-5876

Myocardial Structural Alteration and Systolic Dysfunction in Preclinical Hypertrophic Cardiomyopathy Mutation Carriers

BACKGROUND: To evaluate the presence of myocardial structural alterations and subtle myocardial dysfunction during familial screening in asymptomatic mutation carriers without hypertrophic cardiomyopathy (HCM) phenotype. METHODS AND FINDINGS: Sixteen HCM families with pathogenic mutation were studied and 46 patients with phenotype expression (Mut+/Phen+) and 47 patients without phenotype expression (Mut+/Phen-) were observed. Twenty-five control subjects, matched with the Mut+/Phen- group, were recruited for comparison. Echocardiography was performed to evaluate conventional parameters, myocardial structural alteration by calibrated integrated backscatter (cIBS) and global and segmental longitudinal strain by speckle tracking analysis. All 3 groups had similar left ventricular dimensions and ejection fraction. Basal anteroseptal cIBS was the highest in Mut+/Phen+ patients (-14.0+/-4.6 dB, p-19.0 dB basal anteroseptal cIBS or >-18.0% basal anteroseptal longitudinal strain had a sensitivity of 98% and a specificity of 72% in differentiating Mut+/Phen- group from controls. CONCLUSION: The use of cIBS and segmental longitudinal strain can differentiate HCM Mut+/Phen- patients from controls with important clinical implications for the family screening and follow-up of these patients.published_or_final_versio

Role of computed tomography imaging for transcatheter valvular repair/insertion

During the last decade, the development of transcatheter based therapies has provided feasible therapeutic options for patients with symptomatic severe valvular heart disease who are deemed inoperable. The promising results of many nonrandomized series and recent landmark trials have increased the number of percutaneous transcatheter valve procedures in high operative risk patients. Pre-procedural imaging of the anatomy of the aortic or mitral valve and their spatial relationships is crucial to select the most appropriate device or prosthesis and to plan the percutaneous procedure. Multidetector row computed tomography provides 3-dimensional volumetric data sets allowing unlimited plane reconstructions and plays an important role in pre-procedural screening and procedural planning. This review will describe the evolving role of multidetector row computed tomography in patient selection and strategy planning of transcatheter aortic and mitral valve procedures

Cardiovascular imaging 2011 in the International Journal of Cardiovascular Imaging

Cardiovascular Aspects of Radiolog

Outcomes of obstructed abdominal wall hernia: results from the UK national small bowel obstruction audit

Background: Abdominal wall hernia is a common surgical condition. Patients may present in an emergency with bowel obstruction, incarceration or strangulation. Small bowel obstruction (SBO) is a serious surgical condition associated with significant morbidity. The aim of this study was to describe current management and outcomes of patients with obstructed hernia in the UK as identified in the National Audit of Small Bowel Obstruction (NASBO). Methods: NASBO collated data on adults treated for SBO at 131 UK hospitals between January and March 2017. Those with obstruction due to abdominal wall hernia were included in this study. Demographics, co-morbidity, imaging, operative treatment, and in-hospital outcomes were recorded. Modelling for factors associated with mortality and complications was undertaken using Cox proportional hazards and multivariable regression modelling. Results: NASBO included 2341 patients, of whom 415 (17·7 per cent) had SBO due to hernia. Surgery was performed in 312 (75·2 per cent) of the 415 patients; small bowel resection was required in 198 (63·5 per cent) of these operations. Non-operative management was reported in 35 (54 per cent) of 65 patients with a parastomal hernia and in 34 (32·1 per cent) of 106 patients with an incisional hernia. The in-hospital mortality rate was 9·4 per cent (39 of 415), and was highest in patients with a groin hernia (11·1 per cent, 17 of 153). Complications were common, including lower respiratory tract infection in 16·3 per cent of patients with a groin hernia. Increased age was associated with an increased risk of death (hazard ratio 1·05, 95 per cent c.i. 1·01 to 1·10; P = 0·009) and complications (odds ratio 1·05, 95 per cent c.i. 1·02 to 1·09; P = 0·001). Conclusion: NASBO has highlighted poor outcomes for patients with SBO due to hernia, highlighting the need for quality improvement initiatives in this group