Os montes da serra de Tavira

The human occupation of the Tavira ridge is characterised by a network of small agglomerations of buildings (known as ‘montes’) belonging to the proprietors of lands around them. This way of organising places is, by and large, extensive to an important area of the schist mountains that stretch from Alentejo to Algarve, from the Guadiana river to the Atlantic Ocean. However, within the scope of that larger entity, the Tavira ridge appears as a sub-unit with traits of its own, which may be attributed not only to biophysical conditions, but also to the historical circumstances associated to the settlement of the territory. This particular ridge, which was confined to the perimeter of the Tavira municipality during the days of the Old Regime, has been more densely populated, due to its lack of interior hierarchisation, unlike what happens in neighbouring sub-units, both in terms of agglomeration sizes and of the property system itself. The traditional architecture of these areas was usually reduced to the bare essentials, reflecting the adverse conditions that generally surrounded the local economies. As can easily be gleaned from the plans shown here, the groupings of edifices that define the ridge’s settlement are largely characterised by the aggregation of buildings belonging to various owners, often intent on achieving a prominent position in the landscape.

How do analysts deal with bad news? Going-concern opinions and analyst behaviour

Tese dout., University of Edinburg, 2008

Ecological niche modeling, cytogenetics and phylogeography of the genera Geomalacus and Letourneuxia (Gastropoda, Pulmonata) from the Iberian-Moroccan region

First described more that 150 years ago, the systematics of the genera Geomalacus and Letourneuxia (Arionidae, Gastropoda, Pulmonata) is still challenging. The taxonomic classification of arionid species is based on extremely labile characters such as body size or color that depends both on diet and environment, as well as age. Moreover, there is little information on the genetic diversity and population structure of the Iberian slugs that could provide extra clues to disentangle their problematic classification. The present work uses different analytical tools such as habitat suitability (Ecological Niche Modeling - ENM), cytogenetic analysis and phylogeography to establish the geographical distribution and evolutionary history of these pulmonate slugs. The potential distribution of the four Geomalacus species was modeled using ENM, which allowed the identification of new locations for G. malagensis, including a first report in Portugal. Also, it was predicted a much wider distribution for G. malagensis and G. oliveirae than previously known. Classical cytogenetic analyses were assayed with reproductive and a novel use of somatic tissues (mouth and tentacles) returning the number of chromosomes for the four Geomalacus species and L. numidica (n = 31, 2n = 62) and the respective karyotypes. G. malagensis and L. numidica present similar chromosome morphologies and karyotypic formulae, being more similar to each other than the Geomalacus among themselves. We further reconstructed the phylogeny of the genera Geomalacus and Letourneuxia using partial sequences of the mitochondrial cytochrome oxidase subunit I (COI) and the nuclear ribosomal small subunit (18S rRNA), and applied an independent evolutionary rate method, the indicator vectors correlation, to evaluate the existence of cryptic diversity within species. The five nominal species of Geomalacus and Letourneuxia comprise 14 well-supported cryptic lineages. Letourneuxia numidica was retrieved as a sister group of G. malagensis. G. oliveirae is paraphyletic with respect to G. anguiformis. According to our dating estimates, the most recent common ancestor of Geomalacus dates back to the Middle Miocene (end of the Serravallian stage). The major lineage splitting events within Geomalacus occurred during the dry periods of the Zanclean stage (5.3-3.6 million years) and some lineages were confined to more humid mountain areas of the Iberian Peninsula, which lead to a highly geographically structured mitochondrial genetic diversity. The major findings of this are the following: (1) provides updated species distribution maps for the Iberian Geomalacus expanding the known geographic distribution of the concerned species, (2) unravels the cryptic diversity within the genera Geomalacus and Letourneuxia, (3) Geomalacus oliveirae is paraphyletic with G. anguiformis and (4) Letourneuxia numidica is sister group of G. malagensis.