Linking food web functioning and habitat diversity for an ecosystem based management: a Mediterranean lagoon case-study.

We propose a modelling approach relating the functioning of a transitional ecosystem with the spatial extension of its habitats. A test case is presented for the lagoon of Venice, discussing the results in the context of the application of current EU directives. The effects on food web functioning due to changes related to manageable and unmanageable drivers were investigated. The modelling procedure involved the use of steady-state food web models and network analysis, respectively applied to estimate the fluxes of energy associated with trophic interactions, and to compute indices of food web functioning. On the long term (hundred years) temporal scale, the model indicated that the expected loss of salt marshes will produce further changes at the system level, with a lagoon showing a decrease in the energy processing efficiency. On the short term scale, simulation results indicated that fishery management accompanied by seagrass restoration measures would produce a slight transition towards a more healthy system, with higher energy cycling, and maintaining a good balance between processing efficiency and resilience. Scenarios presented suggest that the effectiveness of short term management strategies can be better evaluated when contextualized in the long term trends of evolution of a system. We also remark the need for further studying the relationship between habitat diversity and indicators of food web functioning.

Detection of antigenic determinants in the Treponema pallidum membrane protein TmpA using overlapping synthetic peptides.

The antigenic structure of the 42 kDa membrane protein of Treponema Pallidum, TmpA, was studied using synthetic peptides. Ten overlapping peptides, 35-40 residues each, were synthesized in order to cover the entire sequence of the molecule. The antigenic activity of the fragments was examined by enzyme-linked immunosorbent assay (ELISA). In this way it was possible to demonstrate a significant antigenic activity of four peptides which were reactive with syphilitic sera. The N-terminal fragment TmpA1, 38 residues long, proved to be the most reactive. Its antigenic structure was therefore studied in more detail, by examining shorter fragments. The N-terminal portion of TmpA1, consisting of 19 residues, (ASGAKEEAEKKAAEQRALL) represents an important fragment of the molecule, and was specifically interactive with most of the syphilitic sera examined.