Holocene evolution of Portus Pisanus, the lost harbour of Pisa.

The ancient harbour of Pisa, Portus Pisanus, was one of Italy's most influential seaports for many centuries. Nonetheless, very little is known about its oldest harbour and the relationships between environmental evolution and the main stages of harbour history. The port complex that ensured Pisa's position as an economic and maritime power progressively shifted westwards by coastal progradation, before the maritime port of Livorno was built in the late 16th century AD. The lost port is, however, described in the early 5th century AD as being "a large, naturally sheltered embayment" that hosted merchant vessels, suggesting an important maritime structure with significant artificial infrastructure to reach the city. Despite its importance, the geographical location of the harbour complex remains controversial and its environmental evolution is unclear. To fill this knowledge gap and furnish accurate palaeoenvironmental information on Portus Pisanus, we used bio- and geosciences. Based on stratigraphic data, the area's relative sea-level history, and long-term environmental dynamics, we established that at ~200 BC, a naturally protected lagoon developed and hosted Portus Pisanus until the 5th century AD. The decline of the protected lagoon started at ~1350 AD and culminated ~1500 AD, after which time the basin was a coastal lake.

Augmentative and alternative communication: treatment principles and strategies.

This article has attempted to clarify the principles of AAC evaluation and intervention, in part by dispelling myths that have persisted for too long. To the list of general guidelines for deciding when to consider AAC and how to begin breaking down the barriers to full participation by children with severe impairments, we need to add some warning signs that we have learned to heed in our work with these children. These signs are listed in Table 6 and are indicators that aspects of an approach to AAC must be altered or the child may fail to benefit from an intervention. Each sign conflicts in one way or another with current principles of augmentative and alternative communication. We give you these signs along with some possible ways to eliminate or prevent these errors in the future. Providing the best possible set of strategies for communication for a child with severe communication impairments is an enormously complex task. Whether a child can or cannot be assessed with standard procedures or whether he or she has unitary or multiple disabilities, the barriers to communication are many and intricately constructed. Sorting out strategies and how to apply them ordinarily requires input from the consumers of AAC (i.e., the family, child, and primary communication partners), the core team of professionals, as well as a team of specialists in AAC. Conducting evaluations and intervention is challenging because of institutional, bureaucratic, and professional barriers that each member of the team faces. Few, if any, teams can provide services that meet all of the established principles of best practice for every child that it serves. Yet, attempts to identify weaknesses within AAC programs and work to strengthen them must be given high priority in order to provide the best possible AAC services for such children. Only then will it be possible for children with severe communication impairments to overcome their own barriers and begin to participate in their choice of life's activities. That is, after all, the ultimate goal.