Dropped gallstones causing transdiaphragmatic migration and thoracic empyema.

We discuss the case of a 72-year-old female, Asiatic patient who had transdiaphramatic migration of stones after laparoscopic cholecystectomy for a gangrenous cholecystitis. The patient presented with a right thoracic empyema and underwent thoracic decortication. The pertinent literature is reviewed.

Spatial memory of domestic dogs (Canis familiaris) for hidden objects in a detour task.

Spatial memory of domestic dogs (Canis familiaris) for hidden objects was investigated via a visible displacement problem of object permanence with a detour paradigm. Experiment 1 showed that dogs were able to spontaneously locate a disappearing object in a detour situation. In Experiments 2 and 3, dead reckoning and allocentric spatial information were put in conflict.

Duration of dogs' (Canis familiaris) working memory in search for disappearing objects.

Two experiments explored the duration of dogs' working memory in an object permanence task: a delay was introduced between the disappearance of a moving object behind a box and the beginning of the search by the animal. In experiment 1, the dogs were tested with retention intervals of 0, 10, 30, and 60 s. Results revealed that the dogs' accuracy declined as a function of the length of the retention interval but remained above chance for each retention interval.