Large granulation cells on the surface of the giant star π1 Gruis.

Convection plays a major part in many astrophysical processes, including energy transport, pulsation, dynamos and winds on evolved stars, in dust clouds and on brown dwarfs. Most of our knowledge about stellar convection has come from studying the Sun: about two million convective cells with typical sizes of around 2,000 kilometres across are present on the surface of the Sun-a phenomenon known as granulation. But on the surfaces of giant and supergiant stars there should be only a few large (several tens of thousands of times larger than those on the Sun) convective cells, owing to low surface gravity. Deriving the characteristic properties of convection (such as granule size and contrast) for the most evolved giant and supergiant stars is challenging because their photospheres are obscured by dust, which partially masks the convective patterns. These properties can be inferred from geometric model fitting, but this indirect method does not provide information about the physical origin of the convective cells. Here we report interferometric images of the surface of the evolved giant star π1 Gruis, of spectral type S5,7. Our images show a nearly circular, dust-free atmosphere, which is very compact and only weakly affected by molecular opacity. We find that the stellar surface has a complex convective pattern with an average intensity contrast of 12 per cent, which increases towards shorter wavelengths. We derive a characteristic horizontal granule size of about 1.2 × 1011 metres, which corresponds to 27 per cent of the diameter of the star. Our measurements fall along the scaling relations between granule size, effective temperature and surface gravity that are predicted by simulations of stellar surface convection.

Unusual presentation of a curve-shaped Meckel's diverticulum detected on technetium-99m Meckel's scintigraphy.

Complicated Meckel's diverticulum (MD) in pediatric age group may not present with classic symptoms or signs. The routine modalities of investigations for the detection of MD are ultrasonography (US), computerized tomography, and air enema. However, these may miss the diagnosis in cases of atypical patterns of presentation. In such situations, the radionuclide Meckel scan helps to narrow down the diagnosis. The objective of this case report was to present an unusual presentation of MD where the diagnosis was established by a radionuclide scan against other methods which were equivocal. An 8-year-old boy was admitted with features of intestinal obstruction. 99mTc-pertechnetate Meckel's scintigraphy showed localization of tracer in ectopic gastric mucosa. The surgical exploration after the Meckel's scan revealed a curve-shaped MD localized 50 cm proximal to the ileocecal valve. The surgery was completed after a diverticulectomy, and the patient was relived of symptoms. MD scintigraphy can help detect ectopic gastric mucosa in cases of unusual presentation by considering the atypical presentation, variation in shape, and location on Meckel's scan and improve the disease management.

Transmigration of mandibular canines: a review of the literature and report of two cases.

Transmigration of mandibular canines across the midline is rare. Two 14-year-old female patients from South India were found to exhibit this phenomenon. In one patient, the mandibular right canine had crossed the midline and migrated to the left, up to the mesial root apex of the permanent first molar, near the lower border of the mandible. In the other patient, the permanent mandibular left canine had crossed the midline and migrated up to the root of the mandibular right canine. Both of these patients are being observed regularly for further migration. The literature on this rare condition is reviewed and its etiologic possibilities and treatment modalities are discussed.

New protocol to prevent TMJ reankylosis and potentially life threatening complications in triad patients.

The management of patients with the triad of temporomandibular joint (TMJ) ankylosis, micrognathia and obstructive sleep apnea syndrome is challenging for the oral and maxillofacial surgeon because it involves achieving the desired oral opening, correction of micrognathia, and correction of the obstructed airway. Seven of the authors' triad patients, in whom only the release of ankylosis was performed, developed bradycardia and respiratory distress during postoperative jaw physiotherapy, leading to their non-compliance for active jaw physiotherapy and subsequent reankylosis. This paper suggests a new surgical protocol for the management of patients with the triad, to achieve correction of the obstructed airway, relief of the respiratory distress symptoms, correction of micrognathia and restricted mouth opening. It also provides a logical reason for the occurrence of bradycardia following ankylosis release and its potential role in TMJ reankylosis. It emphasizes that the occurrence of bradycardia in triad patients during jaw exercises is dictated by the severity of their apnea-hypopnea index and the degree of narrowing of their posterior airway space. The recognition and prevention of this by the new protocol is discussed in 7 patients.

Comment on "The great Sumatra-Andaman earthquake of 26 December 2004".

Lay et al. (Research Articles, 20 May 2005, p. 1127) estimated a 600-km length for the tsunami source region. Adding tide-gauge data from Paradip, the northernmost of the Indian east-coast stations and therefore the most critical constraint on the northern extent of the source, we estimate that its length was greater by approximately 30%.

Preparation and evaluation of 99mTc(V)-DMSA complex: studies in medullary carcinoma of thyroid.

Consequent to the promising results reported with 99mTc(V)-DMSA for imaging certain types of soft tissue tumors, we have developed methods to prepare this radiopharmaceutical in three ways: from freshly prepared reagents, through the use of a two component kit and use of the standard renal DMSA kit by a modified recipe. The 99mTc(V)-DMSA complex has been subjected to paper electrophoretic and chromatographic procedures and also biodistribution studies. The distinctly different behaviour of this new product compared to that of the well known renal DMSA complex has been clearly established. Scintiimaging in a preliminary clinical trial in patients with medullary carcinoma of the thyroid has been encouraging.