Browsing by Author "Pereira, Ana"
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- Against all odds: a tale of marine range expansion with maintenance of extremely high genetic diversityPublication . Robalo, Joana; Francisco, Sara M.; Vendrell, Catarina; Lima, Cristina S.; Pereira, Ana; Brunner, Benedikt P.; Dia, Mamadou; Gordo, L. S.; Castilho, RitaThe displacement of species from equatorial latitudes to temperate locations following the increase in sea surface temperatures is among the significant reported consequences of climate change. Shifts in the distributional ranges of species result in fish communities tropicalisation, i.e., high latitude colonisations by typically low latitude distribution species. These movements create new interactions between species and new trophic assemblages. The Senegal seabream, Diplodus bellottii, may be used as a model to understand the population genetics of these invasions. In the last decades, this species has undergone an outstanding range expansion from its African area of origin to the Atlantic coast of the Iberian Peninsula, where now occurs abundantly. Mitochondrial and nuclear markers revealed a striking high haplotypic nucleotide and genetic diversity values, along with significant population differentiation throughout the present-day geographical range of the Senegal seabream. These results are not consistent with the central-marginal hypothesis, nor with the expectations of a leptokurtic distribution of individuals, as D. bellottii seems to be able to retain exceptional levels of diversity in marginal and recently colonised areas. We discuss possible causes for hyperdiversity and lack of geographical structure and subsequent implications for fisheries.
- Climatic alterations influence bacterial growth, biofilm production and antimicrobial resistance profiles in aeromonas spp.Publication . Grilo, Miguel L.; Pereira, Ana; Sousa-Santos, Carla; Robalo, Joana; Oliveira, ManuelaClimate change is expected to create environmental disruptions that will impact a wide array of biota. Projections for freshwater ecosystems include severe alterations with gradients across geographical areas. Life traits in bacteria are modulated by environmental parameters, but there is still uncertainty regarding bacterial responses to changes caused by climatic alterations. In this study, we used a river water microcosm model to evaluate how Aeromonas spp., an important pathogenic and zoonotic genus ubiquitary in aquatic ecosystems, responds to environmental variations of temperature and pH as expected by future projections. Namely, we evaluated bacterial growth, biofilm production and antimicrobial resistance profiles of Aeromonas species in pure and mixed cultures. Biofilm production was significantly influenced by temperature and culture, while temperature and pH affected bacterial growth. Reversion of antimicrobial susceptibility status occurred in the majority of strains and tested antimicrobial compounds, with several combinations of temperature and pH contributing to this effect. Current results highlight the consequences that bacterial genus such as Aeromonas will experience with climatic alterations, specifically how their proliferation and virulence and phenotypic resistance expression will be modulated. Such information is fundamental to predict and prevent future outbreaks and deleterious effects that these bacterial species might have in human and animal populations.
- Emotion regulation and job satisfaction levels of employees working in family and non-family firmsPublication . Pimentel, Duarte; Pereira, AnaThe purpose of this paper is to explore the differences between employees working in family and non-family firms regarding their emotion regulation and job satisfaction levels. Moreover, focusing on family firms, we assess the relationship between the employees’ emotion regulation and job satisfaction levels. The empirical evidence is provided by a sample of 178 Portuguese employees, 80 employees of family firms, and 98 non-family firms’ employees, who responded to a questionnaire that included emotion regulation and job satisfaction measures. All respondents work in smalland medium-sized private companies. Although the results do not confirm the first hypothesis, suggesting that employees working on family firms show higher levels of emotion regulation than those of non-family companies, the idea that employees of family companies show higher levels of job satisfaction than employees of non-family companies is confirmed (i.e., Hypothesis 2). Moreover, the results also support the third hypothesis, confirming that emotion regulation levels have a significant and positive relationship with the job satisfaction levels of employees working in family firms. This paper makes several contributions to the research literature by addressing two organizational aspects still under-addressed in the comparison between family and non-family firms, while pursuing to offer insights on the relationship between the emotion regulation and job satisfaction levels of employees working in family firms.
- Molecular and morphological validation of the species of the genus Actinia (Actiniaria: Actiniidae) along the Atlantic Iberian PeninsulaPublication . Pereira, Ana; Cadeireiro, Emília; Ocaña, Oscar; Vukic, Jasna; Šanda, Radek; Mirimin, Luca; Robalo, Joana IsabelThe discrimination between the several species of the genus Actinia occurring in the Northeastern Atlantic and Mediterranean has been made analyzing morphological characters, with emphasis on external coloration patterns and morphology of cnidom structures. In Iberia, the occurrence of more than two species of Actinia has been suggested, but its validity is yet to be confirmed. In this paper, the identity of the species of the genus Actinia occurring along the Atlantic Iberian coast is investigated, analyzing morphological and molecular procedures. For this purpose, genetic data was collected from 140 individuals and two genetic markers were amplified and sequenced (the nuclear 28S and the mitochondrial 16S ribosomal genes). The genetic identification was corroborated by morphological analysis of individuals representing each of the genetic groups found. This procedure led to the identification of three species occurring in the studied area – Actinia equina (L.), A. fragacea Tugwell and A. schmidti Monteiro, Sole-Cava & Thorpe.
- Putting European lampreys into perspective: A global‐scale multilocus phylogeny with a proposal for a generic structure of the PetromyzontidaePublication . Pereira, Ana; Levy, André; Vukić, Jasna; Šanda, Radek; Levin, Boris; Freyhof, Jörg; Geiger, Matthias; Choleva, Lukáš; Francisco, Sara M.; Robalo, JoanaPrevious studies on the phylogenetic relationships between lamprey species relied either on a low number of morphological characters related to the feeding apparatus, or on a low number of molecular mitochondrial DNA markers. Here, we apply a multilocus approach to assess the phylogenetic relationships of northern hemisphere lampreys, with a special emphasis on the 17 European species. The study comprises two mitochondrial (cytochrome c oxidase subunit 1 gene—DNA barcodes, and cytochrome b gene) a nd t wo n uclear (internal transcribed spacers I and II) markers to investigate species' phylogenetic affinities. The phylogeny obtained with mitochondrial markers revealed a clear and highly supported separation of all northern hemisphere lampreys. Among those, our multilocus results show several polyphyletic genera, stressing the need for a taxonomic revision in a near future. Lampetra morii (Berg, 1931) from East Asia, often included in Eudontomyzon, is placed in the genus Lethenteron. Lampetra richardsoni Vladykov & Follett, 1965 and Entosphenus hubbsi (Vladykov & Kott, 1976) should be placed in a new genus, as well as the southern populations of Lethenteron camtschaticum (Tilesius, 1811) and Lethenteron reissneri (Dybowski, 1869). Considering European species, our results argue for a taxonomic revision of Eudontomyzon, with emphasis on Eudontomyzon vladykovi Oliva & Zanandrea, 1959.