Evidence for Liquid Droplets in a -65° Cold Cirrus Observed by LIDAR above Sodankyla (Finland) during SESAME

It is widely accepted that pure water cannot exist as liquid below about -40°C. Theoretical and laboratory studies confirm this behavior for pure water . Nevertheless, liquid droplets have been seldom observed in cirrus clouds down to -50°C. Miltiwaveleght depolarization LIDAR tecnique can help ti hunt usually cold supercooled clouds. The presence of non-depolarizing cloud layers is indicative of scattering with ylindrical symmetry, possible both with spherical droplets and with ice plates horizontally oriented. In this work, a -65°C cold, non- depolarizing cloud observed in Finland is analysed, concluding thath supercooled droplets are responsible for the absence of depolarization in most of the layer.PublishedSchliersee, Germany1.8. Osservazioni di geofisica ambientaleope

Evidence for Biotype-Specific Effects of Bovine Viral Diarrhoea Virus on Biological Responses in Acutely Infected Calves

The relationship between the two biotypes of bovine viral diarrhoea virus (BVDV) and the biological responses they induce was studied in 3- to 6-month-old calves inoculated intranasally with a homologous pair of non-cytopathic and cytopathic strains. Marked differences in virological and serological events occurred following exposure to a specific BVDV strain. The non-cytopathic biotype was frequently recovered from nasal secretions and blood cells during the first 28 days post-inoculation whereas the cytopathic counterpart was detected infrequently in nasopharyngeal swabs only. There was no correlation of the recovery of infectious virus in vivo with the biotype-specific neutralizing humoral immune response. Furthermore, seroconversion did not correlate with resistance to reinfection as judged by the transient viraemia and/or shedding of virus observed in a challenge experiment