sumes responsibility for the teaching of mentally handicapped children and the training of their teachers. On the surface, taking over from the Department of Health appeared to involve a minor readjustment, in fact repercussions have been loud and farreaching. Stanley Segal, principal of Ravenswood Centre for Special Education, clarifies the complexities and warns that the wrangles must be reso...

Distal propulsion of a 28 mm umbrella filter from vena cava to femoral vein occurred in a 75-year-old woman during external cardiac massage. After cardiac massage, filter position must be checked roentgenographically. Optimal management of distal migration might include placement of a second umbrella to prevent recurrent emboli and proximal migration of the dislodged umbrella.

OBJECTIVE To show the institutional experience of closure of interatrial communications with a modified umbrella device. DESIGN Descriptive study of all patients in whom transcatheter umbrella closure of interatrial communications has been attempted. SETTING A tertiary referral centre. PATIENTS 16 patients with 17 interatrial communications of various types. INTERVENTIONS Transcatheter ...

[1] Photographs of a volcanic column in a recent eruption of Reventador show a prominently scalloped umbrella that is unlike any umbrella previously documented on a volcanic column. We propose that the scallops in this umbrella are the result of a turbulent Rayleigh–Taylor (RT) instability, a type of fluid instability with no precedents in volcanology. Negative buoyancy drives this instability,...

The notion of umbrella contingencies is rigorously defined in the context of the security-constrained optimal power flow (SCOPF) problem in both its deterministic and probabilistic forms. The set of umbrella contingencies is a subset of the set of credible contingencies that is sufficient to attain levels of security and economic performance identical or nearly identical to those found when all...

This paper considers the problem of testing for umbrella alternatives in the one-way layout when survival data are subject to random right censorship. Testing procedures based on two-sample weighted logrank statistics are suggested for both cases when the peak of the umbrella is known or unknown. The Pitman efficacy of the peak-known umbrella test is derived. A class of Lehmann and scale altern...