Monoclonal antibodies specific for selected species complexes of Leishmania have been employed for the characterization of several representative strains of Leishmania isolated from different hosts and localities in the Americas. In the past 15 years, data have been accumulated concerning (i) the specificities of a number of these monoclonal antibodies and (ii) the antigenic variation (level of...

Five viruses related to rabies occur in Africa. Two of these, Obodhiang from Sudan and kotonkan from Nigeria, were found in insects and are only distantly related to rabies virus. The other three are antigenically more closely related to rabies. Mokola virus was isolated from shrews in Nigeria, Lagos bat virus from fruit bats in Nigeria, and Duvenhage virus from brain of a man bitten by a bat i...

Many bacterial pathogens are exquisitely adapted to host parasitization. Their niche is primarily determined by the biochemical milieu of the host. As such, pathogens are selected to exhibit environmentally responsive and adaptive molecular traits which allow adherence, entrance, and replication within the host (7, 26). One major set of selective forces which operates to shape the phenotype of ...

This research explores the causes of dealer demand amplification leading to a high volume of seed returns in a typical agribusiness supply chain. Seed production occurs months in advance of grower demand, resulting in a limited supply of specific seeds. To hedge against shortages, dealers inflate orders. If demand materializes, dealers benefit from their inflationary behavior. If it does not, t...

To provide more insights into the responses of the soil seed bank and vegetation to human disturbance intensity, we selected four land use types, including: native grassland (no human disturbance), abandoned artificial grassland (light human disturbance), artificial grassland (moderate human disturbance), and farmland (severe human disturbance) in a semi-arid climate of northern China. The spec...

Seed banking remains a cornerstone in the conservation of plant genetic resources. To be successful, it relies on the collecting and banking of high-quality seeds. In 1995 there was relatively little guidance available to seed collectors (especially of wild plant species), who had to make decisions in the field about what to collect and how to handle collected material. Since then, research int...

—Pocket gophers have the potential to alter the dynamics of grasslands by creating mounds that bury existing vegetation and locally reset succession. Gopher mounds may provide safe sites for less competitive species, potentially increasing both species diversity and vegetation heterogeneity (spatial variation in species composition). We compared species composition, diversity and heterogeneity ...

The lipooligosaccharide (LOS) of Haemophilus somnus undergoes antigenic phase variation, which may facilitate evasion from the bovine host immune response and/or colonization and dissemination. However, LOS antigenic diversity in H. somnus has not been adequately investigated. In this study, monoclonal antibodies (MAbs) specific to various LOS epitopes were used to investigate antigenic variati...

Antigenic diversity among ribonucleic acid (RNA) viruses occurs as a result of rapid mutation during replication and recombination/reassortment between genetic material of related strains during co-infections. Variants which have a selective advantage in terms of ability to spread or to avoid host immunity become established within populations. Examples of antigenically diverse viruses include ...