Are there differences in immune function between continental and insular birds?

Generally, immune system architecture varies with different environments, which presumably reflect different pathogen pressures. Specifically, populations from relatively disease-free, oceanic islands are expected to exhibit reorganized immune systems, which might be characterized by attenuated responses, given the costs of immune function. Some insular animals exhibit an ‘island syndrome,’ including increased susceptibility to disease, and some insular populations have declined when they failed to resist infection by introduced pathogens. I measured eight indices of immune function (haemolysis, haemagglutination, concentration of haptoglobin and concentration of five leukocyte types) in 15 phylogenetically matched pairs of bird populations from North America and from the islands of Hawaii, Bermuda and the Galápagos. Immune responses were not attenuated in insular birds, and several indices, including the concentration of plasma haptoglobin, were elevated. Thus, I find no support for the specific hypothesis that depauperate parasite communities and the costs of immune defences select for reduced immune function. Instead, I suggest that life on islands leads to an apparent reorganization of immune function, which is defined by increases in defences that are innate and inducible. These increases might signal that systems of acquired humoral immunity and immunological memory are less important or dysfunctional in island populations

Great discoveries of milk for a healthy diet and a healthy life Grandes descobertas do leite para uma dieta e vida saudáveis

Extensive research in recent years has shown that consumption of milk and dairy products, promotes cardiovascular health, reduces symptoms of the metabolic syndrome in obese individuals, promotes weight loss while maintaining body muscle mass and reduces incidence of some cancers. Detailed analysis of prospective studies in large Western populations over long periods of time demonstrates that higher consumption of dairy products provides an overall survival advantage.<br>Nos últimos anos, inúmeras pesquisas têm mostrado que o consumo de leite e produtos lácteos melhora a saúde cardiovascular, reduz os sintomas da síndrome metabólica em indivíduos obesos, promove a perda de peso, enquanto mantém a massa muscular do corpo, e reduz a incidência de alguns tipos de câncer. A análise detalhada de estudos prospectivos em grandes populações ocidentais durante longos períodos de tempo demonstra que maior consumo de produtos lácteos proporciona uma vantagem de sobrevida global