Elemental analysis of solid samples by low temperature plasma ashing and microwave acid digestion

Sixteen elements (Mn, Zn, Cu, Fe, B, Sr, Ba, Cr, Pb, As, Cd, Ni, Co, Se, Sb, Hg) were determined in oils, sediments, plants and marine organisms by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) or by Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS) after plasma ashing followed by microwave acid digestion with HNO₃/HCl/H₂O₂. Soil and sediment samples were treated directly in the microwave oven without ashing, but the complete procedure must be applied in case of high organic content. The method was tested on a variety of standard reference materials. Good recoveries were obtained for most of the considered trace elements with less time and reagents consumption than conventional open vessels acid digestion procedures. Hg was determined with good recovery in soil samples by the same method and in organic materials by a modified procedure involving digestion of fresh material with nitric acid in a reflux quartz system.     

CoRoT measures solar-like oscillations and granulation in stars hotter than the Sun

Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars.     

Isolation and identification of a South African lentivirus from jaagsiekte lungs

In the course of attempts to grow the jaagsiekte retrovirus in cell culture, a typical lentivirus was isolated for the first time in South Africa from adenomatous lungs. Morphologically the virus could not be distinguished from other lentiviruses, but serologically it was shown to be more closely related to visna virus than to caprine arthritis-encephalitis virus. However, a preliminary restriction enzyme analysis of the linear proviral DNA of this new lentivirus (SA-DMVV) revealed that it is significantly district from visna virus and CAEV and therefore may represent a third type of lentivirus. Antibodies to the virus were demonstrated in a number of sheep in various parts of the country, but a direct link to a disease condition was not found. Attempts to produce lung lesions by intratracheal injection of the virus have been unsuccessful to date but a transient arthritis was produced by intraarticular inoculation. Viral replication seems to be enhanced in jaagsiekte lungs.