Computer networking for scientists

Scientific research has always relied on communication for gathering and providing access to data; for exchanging information; for holding discussions, meetings, and seminars; for collaborating with widely dispersed researchers; and for disseminating results. The pace and complexity of modern research, especially collaborations of researchers in different institutions, has dramatically increased scientists' communications needs. Scientists now need immediate access to data and information, to colleagues and collaborators, and to advanced computing and information services. Furthermore, to be really useful, communication facilities must be integrated with the scientist's normal day-to-day working environment. Scientists depend on computing and communications tools and are handicapped without them.

Analysis of the roles of bluetongue virus outer capsid proteins VP2 and VP5 in determination of virus serotype

Analyses of reassortant and parental strains of BTV serotypes 3 and 10, in serum neutralization tests, confirmed the major role of outer capsid protein VP2 in determination of virus serotype and its involvement in serum neutralization. However, a reassortant BTV strain (R70), containing protein VP5 derived from BTV 3 and VP2 derived from BTV 10, cross-neutralized with both parental virus strains (BTV 3 and BTV 10). It is concluded that VP5 also plays some part in serotype determination of these virus isolates, as analyzed by serum-neutralization, but its role may be less significant than that of VP2.

The vector potential of British Culicoides species for bluetongue virus

Two species of British Culicoides, C. nubeculosus and C. impunctatus were found to support bluetongue virus (BTV) multiplication after ingestion of the virus. Both species were infected by membrane feeding and C. nubeculosus also became infected after feeding on viraemic sheep. This species was shown to transfer the virus across a membrane after 8 days incubation at 25 degrees C and could therefore presumably act as a BTV vector. Six other British species of Culicoides supported BTV multiplication after intrathoracic inoculation of the virus.

Variation in the responses of Culicoides variipennis (Diptera, Ceratopogonidae) to oral infection with bluetongue virus

The infection rate of an established colony of Culicoides variipennis to oral infection with bluetongue virus (BTV) type 4 was found to be highly variable and ranged from 0 to 51.6 per cent. This type of wide variation has previously only been reported to occur between individual populations of a species and not between samples from a single population. This must be taken into account when such colonies are used as reference standards for interpretation of field and laboratory data, particularly relating to studies of vector efficiency. Study of the response of individual susceptible C. variipennis to BTV infection demonstrated considerable variation in the level of virus multiplication that individual females are able to support. Virus concentrations varied from less than 1.1 to 5.1 log10 TCID50/fly up to 10 days post infection. 43.6 per cent of females contained less than 2.5 log10 TCID50 virus. It is suggested that such insects would have a mesenteron escape barrier to infection and would be incapable of transmitting BTV. The implications of these results for vector research are discussed.

Isolation of bluetongue and related viruses from Culicoides spp. in the Sudan

Infection of domestic ruminants with bluetongue virus (BTV) is widespread in the Sudan but there are no records of vector species of Culicoides in that country. Therefore, light-trap collections of Culicoides for virus isolation procedures were made in the Khartoum and Um Benein areas of the Sudan during September-October 1982. Two virus isolates were made from pools of unengorged, female Culicoides. An isolate from a pool of C. kingi (schultzei gp) is a member of the Epizootic Haemorrhagic Disease (EHD) serogroup. The other isolate from a pool of C. imicola, a known BTV vector in other parts of Africa, is type-5 BTV. In laboratory experiments, the North American vector of BTV, C. variipennis, supported replication of both Sudanese isolates to a high titre and transmission occurred after 10 days' incubation. This paper records the first isolation in the Sudan of arboviruses from Culicoides, with the identification of a BTV serotype and the presence of a member of the EHD (genus orbivirus, family Reoviridae) serogroup.

Infection of Israeli culicoides with African horse sickness, blue tongue and akabane viruses

Type 9 African horse sickness virus and type 4 bluetongue virus multiplied to a high titre in an Israeli strain of Culicoides puncticollis after intrathoracic inoculation. Akabane virus persisted for at least 10 days in this midge after intrathoracic inoculation but with little evidence of virus multiplication. All 3 viruses failed to multiply in C. puncticollis after ingestion by the oral route and all were inactivated by 4 days post infection. Five other species of Israeli Culicoides supported multiplication of bluetongue virus after intrathoracic inoculation.