3 research outputs found
Genetic structure of Leucojum aestivum L. in the Po Valley (N-Italy) drives conservation management actions
The aim of this study was to assess the genetic variation and population structure of the geophyte Leucojum aestivum L.
across the Po river valley (N-Italy), to inform conservation management actions with the selection of most suitable source
populations for translocation purposes. L. aestivum is self-incompatible and occurs in S-Europe in fragmented wetlands
and lowland forests along rivers. The species is particularly interesting for habitat restoration practices for its simplicity
of ex situ conservation and cultivation. AFLP analyses were carried out on 16 fragmented populations, using four primer
combinations. Correlations between genetic variation and demographic and ecological traits were tested. AFLP produced
a total of 202 bands, 95.5% of which were polymorphic. Our results suggest that L. aestivum holds low to moderate levels
of genetic diversity (mean Nei\u2019s genetic diversity: H = 0.125), mostly within-population. We found a gradient of two main
biogeographic groups along western and eastern populations, while the STRU CTU RE analysis found that the most likely
number of clusters was K = 3, shaping a partially consistent pattern. We explain the unusual negative correlation between
genetic variation and population size with the high rate of vegetative reproduction. The levels of population differentiation
suggest that fragmentation in L. aestivum populations has occurred, but that an active gene flow between fragmented populations
still exists, maintained by flooding events or pollinators. Conservation management actions should improve habitat
connectivity, especially for pollinators that vehicle upstream gene flow. Moreover, the west\u2013east structure due to the lithological
composition of the gravel and sand forming the alluvial plain of the Po river, should be considered when selecting
source populations for translocation purposes
Genetic structure of Leucojum aestivum L. in the Po Valley (N-Italy) drives conservation management actions
Unruptured Aneurysms Italian Study (UAIS) background and method
Treatment of unruptured cerebral aneurysms still represents an unsettled question in neurosurgical and neuroradiological communities. Although nowadays the indication for treatment have become relatively clear, indeed uncertainity remains for what concerns the proper treatment modality (surgical or endovascular) in terms of both the risk and the mid and long-term efficacy of the two procedures. The "Unruptured Aneurysms Italian Study" is a cooperative prospective study which aims to delineate the "State of the Art" in a nation based population. It has been designed: 1) to depict the nationwide modality of treatment of Unruptured Aneurysms, 2) to assess in the most objective way the overall treatment-related mortality and morbidity as well as the surgical and endovascular risk in the respective patient populations (it is not a surgical versus endovascular study) and 3) to asses the efficacy of the different procedures in the mid and long term periods. The study started on June 2003 and to June 2006, 637 patients have been enrolled. The study will end when the 1000th patient is enrolled