The island rule is the phenomenon of the miniaturization of large animals and the gigantism of small animals on islands, with mammals providing the classic case studies. Several explanations for this pattern have been suggested, and departures from the predictions of this rule are common among mammals of differing body size, trophic habits, and phylogenetic affinities. Here we offer a new explanation for the evolution of body size of large insular mammals, using evidence from both living and fossil island faunal assemblages. We demonstrate that the extent of dwarfism in ungulates depends on the existence of competitors and, to a lesser extent, on the presence of predators. In contrast, competition and predation have little or no effect on insular carnivore body size, which is influenced by the nature of the resource base. We suggest dwarfism in large herbivores is an outcome of the fitness increase resulting from the acceleration of reproduction in low-mortality environments. Carnivore size is dependent on the abundance and size of their prey. Size evolution of large mammals in different trophic levels has different underlying mechanisms, resulting in different patterns. Absolute body size may be only an indirect predictor of size evolution, with ecological interactions playing a major role.

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To evaluate the features and the course of cardiomyopathy in Becker muscular dystrophy, 68 patients--identified by clinical assessment and by reduced dystrophin labeling and/or DNA analysis--were followed in the years 1976-1993, for periods ranging from 3 to 18 years (mean 8). Patients periodically underwent clinical, electrocardiographic, echocardiographic, nuclear, and radiological assessments. Preclinical cardiac involvement was found in 67.4% of patients under 16 years of age, decreasing to 30% in patients older than 40. Clinically evident cardiomyopathy was found in 15% of patients under 16 years of age, increasing to 73% in patients older than 40. A real, dilated cardiomyopathy is the most frequent type of myocardial involvement after the age of 20. Results show that the severity of cardiac involvement can be unrelated to the severity of skeletal muscle damage and confirm that cardiac dysfunction is a primary feature of Becker muscular dystrophy.

This study confirms the role of birds of prey as a reservoir of enteropathogenic bacteria (i.e. Campylobacter spp., Escherichia coli, Salmonella spp.). Wild birds can contaminate environment with their faeces and play a crucial role in the transmission of pathogens to poultry and livestock farms and aquifers supplying water to humans. Furthermore, wild birds could disseminate pathogens within rescue and rehabilitation centres where they are admitted.

This study was aimed at evaluating the prevalence of Campylobacter spp., Escherichia coli O157, Salmonella spp., and related virulence factors (the cdt, stx, and eae genes) in urban pigeons of the coastal area of the Campania region (southern Italy). To achieve this goal, cloacal swab samples from a total of 1800 urban pigeons were collected and subjected to culture methods, PCR, and serotyping. The results of the present study showed a prevalence of 48.3% (870/1800), 7.8% (141/1800), and 0.9% (16/1800), for C. jejuni, E. coli O157, and S. Typhimurium, respectively. All C. jejuni isolates (870/870) carried cdt genes, whereas all E. coli O157 isolates carried stx genes, and 14.9% (21/141) carried the eae gene. These findings clearly show that urban pigeons in the coastal area of the Campania region may constitute an environmental reservoir of these pathogens, thus representing a source of infection for other birds, livestock, and humans.