Colons instead of full stops

The presence of a colon instead of a full stop indicates that the information following the colon supports, explains or restates the information presented immediately before the colon; for example:

A total of 54684 hours was devoted to staff training and development, which represents 6.8 days per equivalent full time position : this is a 25% increase on 1996 figures.
The discovery of xerxin is not the greatest discovery in modern times: the discovery of xarxin is much greater than the discovery of xerxin.
These findings fuelled an evolution of the concept of short term memory into working memory: a system of memory that processed or worked on information as well as temporarily storing it.

Using a colon in this way suggests a closer relationship between the two sentences than is suggested by a full stop.