Water vapour jets inside the plume of gas leaving Enceladus.

A plume of water vapour escapes from fissures crossing the south polar region of the Saturnian moon Enceladus. Tidal deformation of a thin surface crust above an internal ocean could result in tensile and compressive stresses that would affect the width of the fissures; therefore, the quantity of water vapour released at different locations in Enceladus' eccentric orbit is a crucial measurement of tidal control of venting. Here we report observations of an occultation of a star by the plume on 24 October 2007 that revealed four high-density gas jets superimposed on the background plume. The gas jet positions coincide with those of dust jets reported elsewhere inside the plume. The maximum water column density in the plume is about twice the density reported earlier. The density ratio does not agree with predictions-we should have seen less water than was observed in 2005. The ratio of the jets' bulk vertical velocities to their thermal velocities is 1.5 +/- 0.2, which supports the hypothesis that the source of the plume is liquid water, with gas accelerated to supersonic velocity in nozzle-like channels.

Identification of DNA sequences of both genital and cutaneous HPV types in a small number of keratoacanthomas of nonimmunosuppressed patients.

BACKGROUND: Viral infection was suggested to be etiologically involved in skin tumor development. Data on the association of human papillomavirus (HPV) with keratoacanthomas are still conflicting. OBJECTIVE: Analysis of HPV infection in keratoacanthomas of the general population. METHODS: HPV DNA was detected by nested PCR. To include a broad range of both cutaneous and mucosal HPV types, HPV PCR was performed with two sets of degenerate primers. RESULTS: Considering only beta-globin-positive specimens, HPV DNA was detected in 20% of the specimens obtained from 18% of the patients. The spectrum of HPV types detected contains HPV types 6, 14, 16, 35, 58 and 61. In 1 case, the underlying HPV type was not identified. In 1 specimen with transition towards squamous-cell carcinoma, HPV 16 was detected. CONCLUSIONS: HPV is probably not generally associated with the etiology of keratoacanthoma but may be relevant in individual cases. Oncogenic HPV types may be cofactors for malignant transformation of initially benign skin lesions like keratoacanthomas.