Prevalence of serum neutralising antibody to equine rhinitis A virus (ERAV), equine rhinitis B virus 1 (ERBV1) and ERBV2

The objective of this study was to determine the incidence of serum neutralising (SN) antibody to ERAV, ERBV1 and ERBV2 in a population of horses from birth to 22 years of age. The prevalences of ERAV, ERBV1 and ERBV2 SN antibodies in 381 sera obtained from 291 horses were 37%, 83% and 66%, respectively. ERAV, ERBV1 and ERBV2 maternal antibody was present in foals 12 h postsuckling but by 10-12 months, ERAV SN antibody was not detected in any of the horses, while ERBV1 and ERBV2 SN antibodies were common (83% and 100%, respectively). Sera were obtained from 44 Thoroughbred horses when they were newly introduced into a training centre when their average age was 23 months and a second sample was obtained approximately 7 months later. ERAV SN antibody was present in 8 (18%) when first bled and in 27 (61%) when tested 7 months later. Accordingly 19 of the 44 horses (43%) seroconverted to ERAV within 7 months of entering the training stable. Among all the horses the average ERAV SN antibody titre was relatively high (3796) and in contrast, ERBV1 and ERBV2 titres were relatively low (average 84 and 45, respectively) and often fell to below detectable levels over time and at a rate comparable to new seroconversions in the same group of horses.     

The effect of thiabendazole seedpiece treatment on Monona potatoes in Wisconsin

Seedpiece protectants containing thiabendazole (TBZ) were deleterious to stand establishment and yield and were associated with the formation of secondary tubers from seedpieces on Monona potatoes in four of five years (1980–1984) in Wisconsin. Seed tubers treated with a pre- and/or poststorage mist application of TBZ prior to a post-cutting treatment with a dust formulation containing 0.5% TBZ were most severely affected. The negative effects of pre- and post-cutting TBZ treatment on yield were additive. Observations in grower fields during 1981 indicated that cultivars differed in their sensitivity to this fungicide. Ontario, LaChipper, and Monona were most severely affected while problems were not observed on the Superior and Russet Burbank cultivars.     

Comparison of aircraft,ground-rig and center pivot irrigation systems for application of pesticides to potatoes

Studies were conducted from 1979 to 1983 in central Wisconsin to investigate the utilization of center pivot irrigation systems for the application of pesticides to potatoes. Fungicides, herbicides and insecticides were applied with a conventional tractor-mounted boom sprayer, a boom mounted beneath the center pivot (underslung boom), direct injection into the center pivot irrigation water and by aircraft. In comparisons between irrigation system application and tractor-mounted boom application, materials through both the underslung boom and center pivot system provided comparable pest control to the tractor-mounted boom, with the exception of water soluble insecticides which were ineffective when applied through the irrigation system. In addition, under intense disease pressure a somewhat reduced efficacy was associated with fungicides applied through the center pivot system compared to tractor-mounted boom applications. Comparison of center pivot pesticide applications with aerial and tractor-mounted boom applications in 65 ha commercial fields in 1982 and 1983, showed that all application methods provided acceptable levels of pest control, and comparable tuber yields.     

Effects of Soil Fumigation and Seeding Regimes on Secondary Succession in a Semiarid Shrubland

In order to ascertain the degree to which disturbance and subsequent recovery of belowground biotic components (mycorrhizal and decomposer systems) influence successional dynamics, a portion of semiarid shrubland in northwest Colorado was mechanically disturbed in 1984. Two treatments, soil fumigation (fumigated with methyl bromide and not fumigated) and seeding (early-seral species, late-seral species, and not seeded) were imposed on 500 m2 plots in each of four replications. Aboveground annual production by species, and decomposition rates were measured in 1991, 7 years after the initial disturbance and treatments. Mycorrhizal infection potential had been previously measured at this site from 1984-1988. Seeding to late-seral species resulted in greater production rates (and greater community composition) of late-seral species, whereas seeding to early-seral species had only a minor effect when compared to unseeded plots 7 years after disturbance. Fumigation slowed the rate of succession on unseeded plots, primarily by decreased production of perennial grasses. Mycorrhizal infection potential, initially greatly reduced by the disturbance and by fumigation, recovered to near-background levels on unfumigated plots but not on fumigated plots after 4 years. Decomposition experiments suggest that seeding may have facilitated recovery of the decomposer system after initial disturbance and fumigation. Our results suggest that the redevelopment of soil biotic communities following disturbance has a significant impact on successional dynamics, particularly the replacement of early-seral annuals by mid-seral perennial grasses.     

Distance communication transfer of HIV prevention interventions to service providers

Most acquired immunodeficiency syndrome (AIDS) service providers are in countries with little access to scientific developments relevant to their programs. It is critical to transfer advances from the scientific arena to service providers on a global scale. Human immunodeficiency virus (HIV) prevention organizations in 78 countries were randomized to receive either a control condition or a technology transfer condition with an interactive distance learning computer training curriculum and individualized distance consultation. Of 42 nongovernmental organizations in the technology transfer condition, 29 adopted the science-based program in their communities or trained other agencies to also use it. Advanced communication technologies can create a cost-effective infrastructure to disseminate new intervention models to service providers worldwide.