Maria Teresa Ferreira

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River plants were studied at 119 sites from a southern Iberian river basin. A site length of 50-100 m was found to be adequate for characterising local plant richness in these rivers. Average number of river plant species per site was 48 (range 21-76). Species richness showed a maximum at mid-course, with considerable variation in the upper course and a(More)
The ability to successfully adapt to changing host conditions is crucial for full virulence of bacterial pathogens. Staphylococcus aureus has to cope with fluctuating oxygen concentrations during the course of infection. Hence, we studied the effect of oxygen on glucose metabolism in non-growing S. aureus COL-S cells by in vivo(13)C-NMR. Glucose catabolism(More)
Staphylococcus aureus is an aggressive pathogen and a model organism to study cell division in sequential orthogonal planes in spherical bacteria. However, the small size of staphylococcal cells has impaired analysis of changes in morphology during the cell cycle. Here we use super-resolution microscopy and determine that S. aureus cells are not spherical(More)
The diet composition of largemouth bass, Micropterus salmoides, and pumpkinseed sunfish, Lepomis gibbosus, and its relation to environmental factors was studied in intermittent watercourses of the lower Guadiana basin (southern Iberia) during the particularly dry summer of 1994. Overall, both species took food items similar to those found in their North(More)
Patterns of native and exotic species richness and cover were examined together with the composition of species assemblages along a typical Mediterranean river and across its floodplain. Major goals were to characterize species distribution regarding diverse environmental and habitat features, and to explore floodplain landforms relations using plant(More)
Over the last decade there has been a major rise in the number of attempts at fish conservation and management as a response to the widespread degradation of aquatic ecosystems. The assessments involved are rarely planned and executed with inputs from the species’ life history, particularly their microhabitat use over space and time. The seasonal and size(More)
The effects of two small dams of similar size located in different (second order) streams on the Rivers Poio and Balsemão, were studied during one year to assess the impact on the benthic community. In the first stream, regulation is for hydro-power generation purposes and, in the second one, the dam is used to divert water to a small town. These distinct(More)
Spatial variation in the fish community of the regulated Raia stream (Portugal) was examined during the summer of 1995. Variation in the native fish community (abundance of species-size combinations) was explicitly related to both the abundance of exotic species and habitat variables. The fish community changed in space from assemblages characterised by the(More)
Spatial variation in the native fish community of the lower Guadiana basin (southern Iberia) was related to both biotic (abundance of exotic species) and environmental factors using canonical correspondence analysis, CCA. After choosing the best predictors among the environmental and biotic variables, we partitioned the total variation in native species(More)
The present report describes a three-step approach that was used to characterize and define thresholds for the Least Disturbed Condition in Mediterranean streams of four different types, regarding organic pollution and nutrients, hydrological and morphological alterations, and land use. For this purpose, a common database composed of national reference(More)