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Extreme climatic disturbances provide excellent opportunities to study natural selection in wild populations because they may cause measurable directional shifts in character traits. Insectivorous cliff swallows (Petrochelidon pyrrhonota) in the northern Great Plains must often endure periods of cold weather in late spring that reduce food availability, and(More)
Sizes of most kinds of animal groups vary considerably within a population, with group size often causing direct effects on the fitness of group members. Although the consequences of varying group size have been well studied, the causes of variation in group size remain poorly known for most animals. Groups might vary in size because different individuals(More)
Comparisons across bird species have indicated that those more exposed to parasites and pathogens invest more in immunological defence, as measured by spleen size. We investigated how spleen volume varied with colony size, parasite load and an individual's colony-size history in the cliff swallow, Petrochelidon pyrrhonota, a colonial passerine bird of North(More)
Two novel simian immunodeficiency virus (SIV) strains from wild-caught red-capped mangabeys (Cercocebus torquatus torquatus) from Nigeria were characterized. Sequence analysis of the fully sequenced SIV strain rcmNG411 (SIVrcmNG411) and gag and pol sequence of SIVrcmNG409 revealed that they were genetically most closely related to the recently characterized(More)
The role of antibody in protection against human immunodeficiency virus (HIV-1) has been difficult to study in animal models because most primary HIV-1 strains do not infect nonhuman primates. Using a chimeric simian/human immunodeficiency virus (SHIV) based on the envelope of a primary isolate (HIV-89.6), we performed passive-transfer experiments in rhesus(More)
The distribution and levels of simian immunodeficiency virus (SIV) in tissues and plasma were assessed in naturally infected African green monkeys (AGM) of the vervet subspecies (Chlorocebus pygerythrus) by limiting-dilution coculture, quantitative PCR for viral DNA and RNA, and in situ hybridization for SIV expression in tissues. A wide range of SIV RNA(More)
To determine roles of MHC class I and II genes in protection against Toxoplasma gondii, H-2 congenic and mutant mice were infected perorally with bradyzoites of T. gondii and brain cysts were enumerated 30 days later. As B10 mice (H-2b) are cyst susceptible and B10.A mice (H-2a) are cyst resistant, B10 congenic mice having the same alleles but different H-2(More)
Eicosanoids and other bioactive lipid mediators are indispensable regulators of biological processes, as demonstrated by the numerous inflammatory diseases resulting from their dysregulation, including cancer, hyperalgesia, atherosclerosis, and arthritis. Despite their importance, a robust strategy comparable with gene or protein array technology for(More)
Polymorphonuclear leukocytes (PMNs) are key in innate immunity, but their role in viral pathogenesis is incompletely understood. In infection due to West Nile virus (WNV), we found that expression of 2 PMN-attracting chemokines, Cxcl1 and Cxcl2, was rapidly and dramatically elevated in macrophages. PMNs are rapidly recruited to the site of WNV infection in(More)
APOBEC3F (A3F) is a member of the family of cytidine deaminases that is often coexpressed with APOBEC3G (A3G) in cells susceptible to HIV infection. A3F has been shown to have strong antiviral activity in transient-expression studies, and together with A3G, it is considered the most potent cytidine deaminase targeting HIV. Previous analyses suggested that(More)