230,225 research outputs found
The action functional for Moyal planes
Modulo some natural generalizations to noncompact spaces, we show in this
letter that Moyal planes are nonunital spectral triples in the sense of Connes.
The action functional of these triples is computed, and we obtain the expected
result, ie the noncommutative Yang-Mills action associated with the Moyal
product. In particular, we show that Moyal gauge theory naturally fit into the
rigorous framework of noncommutative geometry.Comment: latex, 10 page
Spontaneous resolution of atrial and ventricular septal defects in Malta
Congenital heart disease (CHD) is the commonest congenital malformation, and ventricular septal defect (VSD) and atrial septal defect (ASD) are the commonest forms of CHD. This study was undertaken to determine rates or spontaneous closure or lesions diagnosed at echocardiography after detection or a murmur in Maltese patients born in 1990-94. A significant excess or ASD and VSD was found in Malta, and this was attributed to early echocardiographic diagnosis or small defects, prior to spontaneous closure. A high spontaneous closure rate was round for both ASD and VSD. Rate of closure for both defects was initially high, and tapered off at about 5 to 7 years or age for both lesions. ASDs in excess of 8 mm in diameter at presentation also underwent spontaneous resolution, which is contrary to the known natural history or these defects. Larger VSDs were shown to have a smaller likelihood or closing (p=0.04). Parents and patients can be reassured that spontaneous closure is very likely to occur in the vast majority of these conditions.peer-reviewe
- …