A dense ring of the trans-Neptunian object Quaoar outside its Roche limit.

Planetary rings are observed not only around giant planets, but also around small bodies such as the Centaur Chariklo and the dwarf planet Haumea. Up to now, all known dense rings were located close enough to their parent bodies, being inside the Roche limit, where tidal forces prevent material with reasonable densities from aggregating into a satellite. Here we report observations of an inhomogeneous ring around the trans-Neptunian body (50000) Quaoar.

Congenital dyserythropoietic anaemia and dyskeratosis in Australian Poll Hereford calves.

Congenital dyserythropoietic anaemia (CDA) is a heterogeneous group of rare genetic disorders that in humans is characterised by ineffective haematopoiesis with morphological abnormalities in erythroid precursor cells and secondary iron overload. In the 1990s, a syndrome of CDA with dyskeratosis and progressive alopecia was reported in Poll Hereford calves in Canada and the USA. We report the clinical and pathological findings in two Poll Hereford calves with this syndrome from separate properties in South Australia.

Inguinal panniculitis in a young Tasmanian devil (Sarcophilus harrisii) caused by Mycobacterium mageritense.

A 1-year-old, entire male Tasmanian devil living in captivity was presented because of a nodular inguinal lesion that subsequently developed a draining sinus tract. A second, similar lesion developed later in the ipsilateral axillary region. A deep representative biopsy specimen of abnormal subcutaneous tissue showed chronic active pyogranulomatous inflammation and beaded Gram-positive and acid-fast bacilli situated in lipid vacuoles within the lesion.