Vulnerability of stream biota to climate change in mediterranean climate regions: a synthesis of ecological responses and conservation challenges

Freshwater species worldwide are experiencing dramatic declines partly attributable to ongoing climate change. It is expected that the future effects of climate change could be particularly severe in mediterranean climate (med-) regions, which host many endemic species already under great stress from the high level of human development. In this article, we review the climate and climate-induced changes in streams of med-regions and the responses of stream biota, focusing on both observed and anticipated ecological responses. We also discuss current knowledge gaps and conservation challenges. Expected climate alterations have already been observed in the last decades, and include: increased annual average air temperatures; decreased annual average precipitation; hydrologic alterations; and an increase in frequency, intensity and duration of extreme events, such as floods, droughts and fires. Recent observations, which are concordant with forecasts built, show stream biota of med-regions when facing climate changes tend to be displaced towards higher elevations and upper latitudes, communities tend to change their composition and homogenize, while some life-history traits seem to provide biota with resilience and resistance to adapt to the new conditions (as being short-lived, small, and resistant to low streamflow and desiccation). Nevertheless, such responses may be insufficient to cope with current and future environmental changes. Accurate forecasts of biotic changes and possible adaptations are difficult to obtain in med-regions mainly because of the difficulty of distinguishing disturbances due to natural variability from the effects of climate change, particularly regarding hydrology. Long-term studies are needed to disentangle such variability and improve knowledge regarding the ecological responses and the detection of early warning signals to climate change. Investments should focus on taxa beyond fish and macroinvertebrates, and in covering the less studied regions of Chile and South Africa. Scientists, policy makers and water managers must be involved in the climate change dialogue because the freshwater conservation concerns are huge.

Solasodina em espécies de solanum do cerrado do distrito federal

An isolation method of the steroidal alkaloid solasodine was applied to the fruits of seven species of the Solanum genus from the Federal District. Two of these species show promising yields. The purity of the isolated alkaloid allows it to be transformed it into an intermediate for steroidal drugs production, 16-deshydropregnenolone, and to the lactone vespertiline.

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).