Automated System for Direct Production of [N-13]Ammonia with a Circulating Water-Hydrogen Target

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What does the local structure of a planar graph tell us about its global structure?

The local k-neighborhood of a vertex v in an unweighted graph G = (V,E) with vertex set V and edge set E is the subgraph induced by all vertices of distance at most k from v. The rooted k-neighborhood of v is also called a k-disk around vertex v. If a graph has maximum degree bounded by a constant d, and k is also constant, the number of isomorphism classes of k-disks is constant as well. We can describe the local structure of a bounded-degree graph G by counting the number of isomorphic copies in G of each possible k-disk. We can summarize this information in form of a vector that has an entry for each isomorphism class of k-disks. The value of the entry is the number of isomorphic copies of the corresponding k-disk in G. We call this vector frequency vector of k-disks. If we only know this vector, what does it tell us about the structure of G? In this paper we will survey a series of papers in the area of Property Testing that leads to the following result (stated informally): There is a k = k(ε,d) such that for any planar graph G its local structure (described by the frequency vector of k-disks) determines G up to insertion and deletion of at most εd n edges (and relabelling of vertices)

The flail mitral valve: Echocardiographic findings by precordial and transesophageal imaging and doppler color flow mapping

AbstractTo determine the echocardiographic and Doppler characteristics of mitral regurgitation associated with a flail mitral valve, precordial and transesophageal echocardiography with pulsed wave and Doppler color flow mapping was performed in 17 patients with a flail mitral valve leaflet due to ruptured chordae tendineae (Group I) and 22 patients with moderate or severe mitral regurgitation due to other causes (Group II). Echocardiograms were performed before or during cardiac surgery; cardiac catheterization was also performed in 28 patients (72%). Mitral valve disease was confirmed at cardiac surgery in all patients.By echocardiography, the presence of a flail mitral valve leaflet was defined by the presence of abnormal mitral leaflet ccaptation or ruptured chordae. Using these criteria, transesophageal imaging showed a trend toward greater sensitivity and specificity than precordial imaging in the diagnosis of flail mitral valve leaflet. By Doppler color flow mapping, a flail mitral valve leaflet was also characterized by an eccentric, peripheral, circular mitral regurgitant jet that closely adhered to the walls of the left atrium. The direction of flow of the eccentric jet in the left atrium distinguished a flail anterior from a flail posterior leaflet. By transesophageal echocardiography with Doppler color flow mapping, the ratio of mitral regurgitant jet arc length to radius of curvature was significantly higher in Group I than Group II patients (5.0 ± 2.3 versus 0.7 ± 0.6, p < 0.001); all of the Group I patients and none of the Group II patients had a ratio >2.5.Thus, transesophageal imaging with Doppler color flow mapping of mitral regurgitation is complementary to precordial echocardiography in the diagnosis and localization of flail mitral valve leaflet due to ruptured chordae tendineae

Field surveys and numerical modeling of the 26 December 2004 Indian Ocean tsunami in the area of Mumbai, west coast of India

NERC-UKR