Percorrer por autor "Gomes, Ana"
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- Activation profile of the Atlantic salmon (Salmo salar) calcium-sensing receptor (Casr) by selected L-amino acidsPublication . Gomes, Ana; Gélébart, Virginie; Félix, Rute; Cardoso, João; Zimmermann, Fabian; Lai, Floriana; Power, Deborah Mary; Ronnestad, IvarIn mammals, the calcium-sensing receptor (CaSR) is involved in nutrient sensing and modulated by several amino acids. In teleosts, sequence homologues of the mammalian CaSR have been described but their function in sensing amino acids remains elusive, including in Atlantic salmon (Salmo salar), an important aquaculture species. This study investigated the activation of Atlantic salmon Casr (asCasr)-mediated signaling pathways-Gq, Gi, and ERK1/2-by six selected L-amino acids (histidine, tryptophan, phenylalanine, isoleucine, leucine and valine) and by Ca2+. Using a Flp-In-HEK293 cell line stably expressing asCasr, we confirmed activation of all three pathways. L-histidine, L-phenylalanine, and L-tryptophan triggered Gi signaling independent of Ca-2(+). Notably, no Ca-2(+) concentrations induced Gi activation, but IP1 production increased in a concentration-dependent manner. L-histidine was the only amino acid to activate the Gq pathway without Ca-2(+), and this response was amplified by the presence of Ca-2(+). In the presence of 2.5 mM Ca-2(+), L-phenylalanine and L-tryptophan also activated Gq signaling in a concentration-dependent manner. Additionally, in the presence of 10 mM Ca-2(+), L-histidine, L-phenylalanine, and L-tryptophan triggered ERK phosphorylation. These findings establish asCasr as a functional homologue of mammalian CaSR, activated in a concentration-dependent manner by L-amino acids with an aromatic ring.
- Aplicação multimédia sobre a Ria Formosa e seus fins educacionais (ForDid)Publication . Oliveira, Sónia; Boski, T.; Moura, Delminda; Mendes da Silva de Sousa, Carlos A; Gomes, Ana; Pereira, LauraNa atualidade torna-se inquestionável a necessidade de integrar a aprendizagem com as novas tecnologias de modo a cativar e facilitar a compreensão dos temas abordados através de aplicações didáticas. Durante a última década o Centro de Investigação Marinha e Ambiental (CIMA) assumiu a responsabilidade de criar meios eficazes de comunicação entre o público em geral e a comunidade científica, através de plataformas multimédia interativas. Foram objecto destas aplicações didáticas as várias vertentes do património natural do Algarve. Após o sucesso das primeiras aplicações GuaDid e MonDid visando o Estuário do Rio Guadiana e a Serra de Monchique respectivamente, o desafio de criar e inovar foi acrescido, resultando numa nova aplicação – ForDid, visando a divulgação do importante sistema lagunar Ria Formosa.
- Close to sunlight or deep underground? New data to reconstruct site formation processes at the Middle Paleolithic Escoural cave (southern Portugal)Publication . Alzate-Casallas, Guillermo Alfonso; Gomes, Ana; Ferar, Nolan; Talamo, Sahra; Tassoni, Laura; Cascalheira, João; Barbieri, AlviseThe ability to exploit the deeper levels of cave systems is regarded as complex human behavior. Evidence that Neanderthals possessed this skill remains limited. The site of Escoural, in southern Portugal, is worldwide renowned for the Upper Paleolithic rock art that was performed in the lowermost level of the cave. The site also preserved Middle Paleolithic sequences in a deep chamber (P1) as well as in an area that today lies outside of the cave (P2). Due to the lack of geoarchaeological analyses, it is currently impossible to clarify whether these materials reflect systematic Neanderthal visits to these site areas. In this study we integrated geoarchaeological data and radiocarbon dating to (i) reconstruct site formation processes, and (ii) explore the interaction between Neanderthals and carnivores at Escoural. Micromorphological, stratigraphic, and geochronological results demonstrate that colluviation moved sediments and archaeological finds from upper cave chambers into P1. This process likely mixed separate and distinct assemblages, possibly leading to co-occurring high concentrations of carnivore coprolites and lithic artifacts. In contrast, P2 preserves in situ Neanderthal occupations alternating with carnivore visits. Neanderthal foragers used this area when it was a large chamber located close to the original cave entrance, which was subsequently lost due to roof collapses and likely impacted by modern quarrying activities. These findings align with broader Eurasian patterns indicating that Neanderthals primarily used well-lit karstic cavities rather than deep, enclosed spaces. Moreover, this study underscores that post-depositional processes may have profound impacts on our interpretation of Neanderthal and carnivore cave use.
- Drought, fire and grazing precursors to large-scale pine forest declinePublication . Connor, Simon; Araújo, João; Boski, Tomasz; Gomes, Ana; Gomes, Sandra D.; Leira, Manel; Freitas, Maria da Conceição; Andrade, Cesar; Morales‐Molino, César; Franco‐Múgica, Fátima; Akindola, Rufus B.; Vannière, BorisAim Temperate forests are currently facing multiple stresses due to climate change, biological invasions, habitat fragmentation and fire regime change. How these stressors interact with each other influences how, when and whether ecosystems recover, or whether they adapt or transition to a different ecological state. Because forest recovery or collapse may take longer than a human lifetime, predicting the outcomes of different stressor combinations remains difficult. A clearer vision of future forest trajectories in a changing world may be gained by examining collapses of forests in the past. Here, we use long-term ecological data to conduct a post-mortem examination of the decline of maritime pine forests (Pinus pinaster Ait.) on the SW Iberian Peninsula 7000-6500 years ago. Location Portugal and Spain. Methods We compared four palaeoecological records-two with pine declines and two without-using a multiproxy approach. Bioclimatic differences between the four sites were explored. Proxies for past vegetation and disturbance (fire and grazing) were compared with independent palaeoclimatic records. We performed functional traits analysis and used phase plots to examine the causes of pine decline. Results The pine decline represents a critical transition in SW Iberia, which lies close to maritime pine's bioclimatic limits. Prolonged drought likely killed trees and suppressed the fires that normally stimulate pine germination and pinewood recovery. Increased grazing pressure facilitated the rapid spread of resprouter shrubs. These competed with pine trees and ultimately replaced them. Our data highlight complex interactions between climate, fire, grazing and forest resilience. Main Conclusions The pine decline occurred at least a century after post-fire resprouters overtook obligate seeders in the vegetation, constituting an early-warning signal of forest loss. Fire suppression, resprouter encroachment and grazing may threaten the persistence of Mediterranean forests as droughts become more frequent and extreme.
- The genomics of t’ef and finger millet domestication and spreadPublication . Mekonnen, Degsew; Gomes, Ana; Machado, Rui; Oliveira, HugoThe Northern Highlands of Ethiopia and Eritrea (NHE) were a centre for food production in Africa, hosting one of the earliest agriculture-based complex societies on the continent. The NHE's geographical connections with the Arabian Peninsula, and Nilotic cultures led to the cultivation of southwest Asian crops and African native domesticates in its territory. Additionally, the NHE were also the domestication centre for crops like t'ef (Eragrostis tef (Zucc.) Trotter) and finger millet (Eleusine coracana L. Gaertn L.), after well-adapted local wild plants. Considering the paucity of the archaeobotanical record in the region and food remains' preservation issues, in this study, we aim to investigate the domestication and spread of t'ef and finger millet using genomics and interpreting the results in the light of archaeological proxies. Our data confirmed Eragrostis pilosa and Eleusine coracana subsp. africana as the sole wild progenitors of t'ef and finger millet, respectively. T'ef was initially domesticated in the NHE before spreading into southern Ethiopia and eastwards into southern Arabia. Finger millet spread followed two routes: one leading eastwards through the Red Sea to India, and the other southwards, through Kenya and Uganda, reaching southern Africa.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.
- Geochemical characteristics of sediments along the margins of an atlantic-mediterranean estuary (the Guadiana, Southeast Portugal): spatial and seasonal variationsPublication . Camacho, Sarita; Moura, Delminda; Connor, Simon; Boski, T.; Gomes, AnaThe present work describes spatial and seasonal variability in grain-size, pH and elemental characteristics (TOC, TIC, TN and C/N) in superficial sediments, as well as salinity, temperature and oxygen in the water, within the intertidal range of the Guadiana Estuary, SW Iberian Peninsula, during the year 2010. The results indicate that environmental parameters in the estuary are strongly dependent on spatial patterns, which reflect seasonal oscillations in freshwater discharge. The sediment is generally poorly sorted, with a symmetrical to very finely skewed distribution, in accordance with the low-energy conditions typical of the deposition areas. During winter, heavy rains forced the continuous discharge of Europe’s largest reservoir, the Alqueva dam, creating exceptional hydrodynamic conditions and causing coarser sediment deposition in the estuary. High marsh areas are controlled by flood tides, promoting vertical accretion of muddy sediments, especially silts. The lower areas of the saltmarsh and-mud flat areas are controlled by the ebb, with more efficient export of fines toward the platform and retention of sands, sometimes with significant amounts of bioclasts. In winter (average Q = 654 m3 s -1), salinity remained low throughout the estuary with the highest values (< 3) recorded up to 3 km inland from the river mouth, except in the most confined environments subject to greater evaporation. In summer (average Q = 52 m3 s -1), the estuarine waters are better mixed and significant saltwater intrusion extends approximately 8 km inland. The seasonal variation in surface water temperature was very high, with a difference of ca 14 º C in the maximum temperature recorded in winter and summer. A clear relationship between elevation (in relation to mean sea level) and organic matter, pH and particle size was observed. In the higher areas of the marsh, where the hydrodynamics is attenuated, differential deposition of fine sediments promotes organic matter entrapment and low pH. Sedimentary organic matter derives from a mixture of native aquatic and terrestrial sources. The mid-upper estuary areas and higher zones of the saltmarsh in the lower estuary incorporate a greater terrestrial component, whereas the low-middle marsh areas of the lower estuary experience a substantial contribution from indigenous aquatic sources. The present data help to understand the present environmental condition of the Guadiana Estuary and contribute baseline data for future climatic and environmental management studies based on sediment-dependent proxies
- Habitats of the Guadiana River estuaryPublication . Gomes, Ana; Camacho, SaritaThe Guadiana River estuary is the most important estuarine system in southern Portugal. The estuary’s variety of habitats supports a great diversity of species. Some of these species have only recently been discovered and are found nowhere else on Earth. This chapter details the current state of knowledge of the estuary’s habitats, with a particular focus on the unseen microscopic flora and fauna that support the entire food chain – and many economic activities – in the estuary.
- Holocene history of Ria Formosa coastal lagoon system (Southern Portugal): borehole evidence and threedimensional paleotopographyPublication . Mendes da Silva de Sousa, Carlos A; Boski, T.; Gomes, Ana; Pereira, Laura; Lampreia, João; Oliveira, SóniaA paleotopographic model of Ria Formosa is presented based on two borehole campaigns and a systematic comparison with previous works, revealing the existence of a complex network of fluvial valleys. Vertical sediment profiles showed a mosaic of changing depositional environments, resulting from local hydrodynamics, sedimentary sources and, to an extent, by the structurally inherited accommodation space. Sedimentological, geochemical and micropaleontological data were put in the context of an age model obtained from 14C datings, pointing to the existence of an estuarine environment subjected to a rapid coastal flooding from ca. 10000 to 7500 cal. years B.P., followed by a period of infilling in an increasingly confined coastal lagoon environment.
- How increasing temperature affects the innate immune system of sea urchin paracentrotus lividus (Lamarck, 1816) reared in a RAS systemPublication . Rodrigues, Ana Filipa; Lourenço, Sílvia; Gomes, Ana; Tchobanov, Carolina F.; Pombo, Ana; Baptista, TeresaThe purple sea urchin, Paracentrotus lividus, is the most exploited and economically important in Southern Europe due to the high value of its gonads. Temperature generally affects several physiological functions of marine invertebrates and the ocean warming has been linked to increasing frequency and severity of disease outbreaks in several echinoderms. Sea urchins have an innate immune system consisting of coelomocytes, the cellular components responsible for the immune response, supported by proteases and lysozymes. The present study aimed to investigate the effect of increasing seawater temperature on the immunological response of P. lividus. In this experiment, the animals were exposed to an increase in temperature up to 24 degrees C for 36 days, after which cellular and humoral immunity parameters were measured. The number of coelomocytes in the animals increased with the temperature rise, mainly the phagocytes and the colourless granulocytes. In the humoral response of the animals, only the concentration of lysozyme responded to the increase in temperature.
- Hydro-sedimentary processes in a beach-headland systemPublication . Moura, Delminda; Veiga-Pires, C.; Oliveira, Sónia; Horta, João; Nascimento, Ana; Gomes, Ana; Guerra, LilianaUnderstanding hydro-sedimentary processes in space-limited environments as embayed beaches is a key question to reconstruct preterit and predict future coastal evolution forced by the mean sea level rise. Moreover, such knowledge is a fundamental management tool in areas where coastal erosion is currently a worrying fact. This work aims thus to assess the sedimentary contribute, provided by the alongshore transport, to feed embayed beaches. At the southernmost rocky coast of Portugal (Algarve), beaches occurring at the cliffs’ foot are separated by headlands connected to shore platforms forming littoral cells as a consequence of the extremely karstified carbonate landscape. The survival of those beaches depends almost exclusively on the alongshore drift.
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