Stochastic Seismic Emission From Acoustic Glories and the Quiet Sun

Abstract. Helioseismic images of multipolar active regions show enhanced seismic emission in 5-mHz oscillations in a halo surrounding the active region called the ‘acoustic glory’. The acoustic glories contain elements that sustain an average seismic emission 50 % greater than similar elements in the quiet Sun. The most intense seismic emitters tend to form strings in non-magnetic regions, sometimes marking the borders of weak magnetic regions and the separation between weak magnetic regions of opposite polarity. This study compares the temporal character of seismic emission from acoustic glories with that from the quiet Sun. The power distribution of quiet-Sun seismic emission far from solar activity is exponential, as for random Gaussian noise, and therefore not perceivably episodic. The distribution of seismic power emanating from the most intense elements that comprise the acoustic glories is exponential out to approximately 4 times the average power emitted by the quiet Sun. Above this threshold the latter distribution shows significant saturation, suggesting the operation of a hydromechanical non-linearity that sets limits on the acoustic power generated by the convection zone. This could give us considerable insight into the physical mechanism of seismic emission from the near subphotosphere. 1

Multicentric giant cell tumor: report of five new cases.

The typical giant cell tumor (GCT) is a solitary neoplams that occurs in the epiphysis or epimetaphysis of long bones. GCT is seen with a slightly increased frequency in females, and 70% of patients are between 20 and 40 years of age at the time of presentation. Multicentric giant cell tumor (MGCT; two or more centers) is an unusual variant of GCT. Patients with MGCT are likely to be younger than those with a solitary lesion. The multicentric variety is often of a higher stage at diagnosis and is more often associated with a pathological fracture than the unifocal tumor. We are reporting five new cases of MGCT, with a total of 21 tumors seen over a period of 25 years from 1967 to 1992

Multicentric giant cell tumor: report of five new cases.

The typical giant cell tumor (GCT) is a solitary neoplams that occurs in the epiphysis or epimetaphysis of long bones. GCT is seen with a slightly increased frequency in females, and 70% of patients are between 20 and 40 years of age at the time of presentation. Multicentric giant cell tumor (MGCT; two or more centers) is an unusual variant of GCT. Patients with MGCT are likely to be younger than those with a solitary lesion. The multicentric variety is often of a higher stage at diagnosis and is more often associated with a pathological fracture than the unifocal tumor. We are reporting five new cases of MGCT, with a total of 21 tumors seen over a period of 25 years from 1967 to 1992