Frequency Subband Processing and Feature Analysis of Forward-Looking Ground-Penetrating Radar Signals for Land-Mine Detection

There has been significant amount of study on the use of ground-penetrating radar (GPR) for land-mine detection. This paper presents our analysis of GPR data collected at a U.S. Army test site using a new approach based on frequency subband processing. In this approach, from the radar data that have over 2.5 GHz of bandwidth, we compute separate radar images using the one wide (2 GHz) and four narrow (0.6 GHz) frequency subbands. The results indicate that signals for different frequency subbands are significantly different and give very different performance in land-mine detection. In addition, we also examine a number of features extracted from the GPR data, including magnitude and local-contrast features, ratio between copolarization and cross-polarization signals, and features obtained using polarimetric decomposition. Feature selection procedures are employed to find subsets of features that improve detection performance when combined. Results of land-mine detection, including performance on blind test lanes, are presented     

Breaking and merging of liquid sheets and filaments

The surface of a sheet of liquid which contracts due to surface tension, breaks, and then pulls apart into two pieces, is calculated. Before breaking, the flow is the self-similar one found by Keller, Milewski and Vanden-Broeck. After breaking, it is the self-similar flow found by Keller and Miksis. A general numerical scheme, which includes the previous ones, is presented and new numerical results are discussed. There is an analogous flow of an axially symmetric liquid filament, but it is not calculated.     

Time course of coronary endothelial healing after injury due to ischemia and reperfusion

BACKGROUND: Although it has been demonstrated in short-term preparations that ischemia with early reperfusion results in coronary vascular injury manifested by abnormal endothelium-dependent relaxation and increased permeability to plasma proteins, it has not been clear whether these abnormalities are permanent or reversible. METHODS AND RESULTS: In a canine model, regional coronary ischemia was accomplished by 1 hour of left anterior descending coronary artery ligation, and follow-up studies were performed after reperfusion for 1 hour, 48 hours, 2 weeks, or 9 weeks. Vasorelaxation was measured in vitro with preconstricted epicardial coronary artery rings subjected to increasing concentrations of the endothelium-dependent vasodilator ADP and the endothelium-independent vasodilator nitroprusside. At 1 and 48 hours of reperfusion, relaxation of rings from the ischemic reperfused artery to ADP was blunted, but relaxation to nitroprusside was normal. At 2 weeks there was a nonsignificant trend toward a blunted response to ADP in the ischemic/reperfused rings, and at 9 weeks a completely normal response to ADP was observed. Coronary microvascular permeability was assessed by measurement of protein leak index (PLI), by using a double-isotope technique with autologous radiolabeled transferrin and erythrocytes. At 1 and 48 hours of reperfusion there were substantial increases in PLI in the previously ischemic regions, indicative of increased extravascular transferrin. There was a small increase in PLI at 2 weeks but a completely normal measurement at 9 weeks. Electron microscopy of ischemic/reperfused vessels demonstrated endothelial cell swelling and other abnormalities in epicardial arteries and the microcirculation at 48 hours of reperfusion but normal endothelium at 2 weeks of reperfusion. CONCLUSIONS: After 1 hour of regional coronary ischemia, coronary endothelial injury occurs early in reperfusion with abnormalities in epicardial coronary artery endothelium-dependent relaxation, coronary microvascular permeability, and both epicardial coronary artery and microvascular histology. This pattern of injury persists for at least 48 hours, but there is partial functional and complete histological recovery within 2 weeks and complete functional recovery within 9 weeks.     

Discovery of TBC11251, a potent, long acting, orally active endothelin receptor-A selective antagonist

Previously we reported the discovery of amidothiophenesulfonamides as endothelin receptor-A antagonists with high potency and selectivity. Replacement of an amide group in this class of compounds with an acetyl group maintained the in vitro binding affinity and in vivo activity while providing a compound with oral bioavailability and longer duration of action. The optimal compound discovered during these studies, 15q (TBC11251), binds competitively to human ETA receptors with a Ki of 0.43 +/- 0.03 nM and an IC50 of 1.4 nM (IC50 for ETB = 9800 nM). This compound inhibits ET-1-induced stimulation of phosphoinositide turnover with a Ki of 0.686 nM and a pA2 of 8.0. The compound has a serum half-life in the rat and the dog of 6-7 h and 60-100% oral bioavailability. This compound is one of the most selective ETA antagonists reported and therefore is suitable for additional pharmacological and clinical investigation of the role of ETA receptors in diseases.     

Menopause and its sequelae: an interdisciplinary syndrome

Menopausal loss of ovarian estradiol production has numerous unfavourable effects on woman's health. Frequency and intensity of hot flushes mostly decline after some years. However, urogenital atrophy, incontinence, bone loss and rising risk for cardiovascular disease and probably for M. Alzheimer are of greatest importance as their incidence increases after menopause and because they play a major role in causing morbidity and mortality in elderly women. We discuss the pathophysiology of hot flushes, estradiol's effects on bone turnover, on the arterial vessel wall, on serum lipids and some aspects of estradiol action in the brain.     

Clear acrylic resin T-bar used in denture identification

A preformed, T-shaped, clear acrylic resin bar can be utilized as a vehicle for identification of an existing removable dental prosthesis. A printed label attached to the T-bar makes a convenient vehicle for embedding the label in the prosthesis with light-cured acrylic resin. The resultant finished surface of the T-bar assembly provides a protective cover and an exceptionally clear window for viewing the label. The procedure is time-effective and relatively easy.     

Introduction strategies for ATM broadband networks in a Europeancontext

The aim of the European Community's RACE programme has been the introduction of integrated broadband communication services throughout the Community by 1995. Project R1022 is tasked with demonstrating the feasibility of a broadband network based on the asynchronous transfer mode (ATM). The authors consider the alternative ways of introducing ATM broadband networks into the existing European communications structure in a cost-effective manner which offers advantages to network operators and end users     

Neurogenic disorders of heart and lung function in acute cerebral lesions

Incidence and clinical significance of cardiopulmonary complications of acute cerebral lesions are still unclear. Neurogenic pulmonary edema (NPE) is characterized as an acute, protein-rich lung edema occurring shortly after cerebral lesions associated with an acute rise of intracranial pressure. NPE is infrequently diagnosed, usually in association with head trauma. Pathophysiological mechanisms include a rise of the pulmonary vascular hydrostatic pressure either due to sympathetic innervation with pulmonary vasoconstriction or increased left-atrial pressure following systemic arterial hypertension or an increase in pulmonary capillary permeability. In contrast to NPE, cardiac complications are frequently observed, most consistently in patients with subarachnoid hemorrhage. Typical ECG changes are repolarization abnormalities, similar to those observed in coronary heart disease, and cardiac arrhythmias. The CK-MB may be slightly elevated; echocardiographic findings show a depressed left-ventricular function. Pathological examination reveals myofibrillar necrosis. Cardiac complications are explained with overactivity of the sympathetic innervation and high levels of circulating catecholamines. For adequate treatment, close cardiac monitoring is required in all patients with acute cerebral lesions.