Freshwater biodiversity and conservation in mediterranean climate streams of Chile.

In Chile, mediterranean climate conditions only occur in the Central Zone (ChMZ). Despite its small area, this mediterranean climate region (med-region) has been recognised as a hotspot for biodiversity. However, in contrast to the rivers of other med-regions, the rivers in the ChMZ have been studied infrequently, and knowledge of their freshwater biodiversity is scarce and fragmented. We gathered information on the freshwater biodiversity of ChMZ, and present a review of the current knowledge of the principal floral and faunal groups. Existing knowledge indicates that the ChMZ has high levels of endemism, with many primitive species being of Gondwanan origin. Although detailed information is available on most floral groups, most faunal groups remain poorly known. In addition, numerous rivers in the ChMZ remain completely unexplored. Taxonomic specialists are scarce, and the information available on freshwater biodiversity has resulted from studies with objectives that did not directly address biodiversity issues. Research funding in this med-region has a strong applied character and is not focused on the knowledge of natural systems and their biodiversity. Species conservation policies are urgently required in this highly diverse med-region, which is also the most severely impacted and most populated region of the country.

Identification and conservation of remnant genetic resources of brown trout in relict populations from Western Mediterranean streams

Brown trout is a cold-adapted freshwater species with restricted distribution to headwater streams in rivers of the South European peninsulas, where populations are highly vulnerable because Mediterranean regions are highly sensitive to the global climatic warming. Moreover, these populations are endangered due to the introgressive hybridization with cultured stocks. Individuals from six remnant populations in Western Mediterranean rivers were sequenced for the complete mitochondrial DNA control region and genotyped for 11 nuclear markers. Three different brown trout lineages were present in the studied region. Significant genetic divergence was observed among locations and a strong effect of genetic drift was suggested. An important stocking impact (close to 25%) was detected in the zone. Significant correlations between mitochondrial-based rates of hatchery introgression and water flow variation suggested a higher impact of stocked females in unstable habitats. In spite of hatchery introgression, all populations remained highly differentiated, suggesting that native genetic resources are still abundant. However, climatic predictions indicated that suitable habitats for the species in these rivers will be reduced and hence trout populations are highly endangered and vulnerable. Thus, management policies should take into account these predictions to design upstream refuge areas to protect remnant native trout in the region

Statistical Methods for Conservation and Alignment Quality in Proteins

Construction of multiple sequence alignments is a fundamental task in Bioinformatics. Multiple sequence alignments are used as a prerequisite in many Bioinformatics methods, and subsequently the quality of such methods can be critically dependent on the quality of the alignment. However, automatic construction of a multiple sequence alignment for a set of remotely related sequences does not always provide biologically relevant alignments.Therefore, there is a need for an objective approach for evaluating the quality of automatically aligned sequences. The profile hidden Markov model is a powerful approach in comparative genomics. In the profile hidden Markov model, the symbol probabilities are estimated at each conserved alignment position. This can increase the dimension of parameter space and cause an overfitting problem. These two research problems are both related to conservation. We have developed statistical measures for quantifying the conservation of multiple sequence alignments. Two types of methods are considered, those identifying conserved residues in an alignment position, and those calculating positional conservation scores. The positional conservation score was exploited in a statistical prediction model for assessing the quality of multiple sequence alignments. The residue conservation score was used as part of the emission probability estimation method proposed for profile hidden Markov models. The results of the predicted alignment quality score highly correlated with the correct alignment quality scores, indicating that our method is reliable for assessing the quality of any multiple sequence alignment. The comparison of the emission probability estimation method with the maximum likelihood method showed that the number of estimated parameters in the model was dramatically decreased, while the same level of accuracy was maintained. To conclude, we have shown that conservation can be successfully used in the statistical model for alignment quality assessment and in the estimation of emission probabilities in the profile hidden Markov models.

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1845 (SER2,T1 = VOL11).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1907 (VOL71).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1851 (SER2,T7 = VOL17).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1865 (SER4,T1 = VOL31).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1911 (VOL75).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1870 (SER4,T6 = VOL36).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1838 (T4).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1844 (T10).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1901 (VOL65).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1879 (SER5,T7 = VOL45).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1914 (VOL78).

Bulletin monumental / publié sous les auspices de la Société française pour la conservation et la description des monuments historiques ; et dirigé par M. de Caumont

1836 (T2).