Carbon metabolism of intracellular bacteria.
Bacterial metabolism has been studied intensively since the first observations of these 'animalcules' by Leeuwenhoek and their isolation in pure cultures by Pasteur. Metabolic studies have traditionally focused on a small number of model organisms, primarily the Gram negative bacillus Escherichia coli, adapted to artificial culture conditions in the laboratory. Comparatively little is known about the physiology and metabolism of wild microorganisms living in their natural habitats. For approximately 500-1000 species of commensals and symbionts, and a smaller number of pathogenic bacteria, that habitat is the human body. Emerging evidence suggests that the metabolism of bacteria grown in vivo differs profoundly from their metabolism in axenic cultures.Food sharing and perceptions of the status of a relationship.
This study examined how individuals may form an impression of the closeness of the relationship between two individuals based on an observation of them sharing food. An opportunity sample of 72 participants watched a video clip of young adults in same-sex or mixed-sex dyads eating a meal together. In the experimental conditions, each member of the dyad also offered or fed a morsel of food to the other person. Analysis showed that food sharing was seen as indicative of familiarity between the members of a dyad. Actually feeding the other person a morsel of food was seen as an indicator of intimacy in male dyads but not in mixed-sex or female dyads. Results are discussed in terms of expectations