O arquivo distrital da Guarda

O Arquivo Distrital abre as portas ao público em 1984. A partir deste ano, a Guarda passa a ter um repositório para as suas fontes de informação documental, que andavam um pouco perdidas por várias instituições da administração pública, ou à salvaguarda de personalidades, cujo carácter as tornava mais cientes da sua importância e, por isso, as protegia. Os fundos e colecções mais antigos, que estão guardados nos seus depósitos, remontam ao século XVII, mas não são apenas estes que contribuem para a memória histórica da cidade, o edifício no qual funcionam as instalações arquivísticas em causa constitui, ele mesmo, uma fonte viva da memória guardense. O director e restantes funcionários do Arquivo esforçam-se por promover o património arquivístico detido, através da concretização de várias actividades e do cumprimento dos diversos serviços solicitados pelos clientes, ávidos de conhecimento, cada vez mais exigentes ao ponto de obrigarem a repensar toda a prática arquivística até agora realizada a nível mundial. As Tecnologias da Informação e da Comunicação, realidade presente nos sistemas informacionais dos arquivos, permitem uma pesquisa e recuperação da informação sem que seja necessário proceder-se a uma deslocação presencial.The District Archive opens its doors to the public in 1984. From this year on, Guarda has a repository to its sources of documental information, which were lost by various institutions of public administration, or on the custody of personalities, whose character made them more aware of their importance and therefore kept them. The oldest collections stored in its deposits go back to the seventeenth century, but these are not the only ones contributing to the historical memory of the city, the building in which the archival facilities operate is, itself, a living source of Guarda’s inhabitants memory. The director and the other staff of the Archive strive to promote the archival heritage through the implementation of various activities and compliance with the various services required by the clients, who search for knowledge and are each time more demanding. This has leaded to rethink the whole archivist theory practiced, until now, all over the world. Information and Communication Technologies represent a reality in the archives’ systems because they allow a search and retrieval of information without being necessary to go to the place where it is stored

Distinct Bleaching Resilience of Photosynthetic Plastid-Bearing Mollusks Under Thermal Stress and High CO2 Conditions

The impact of temperature on photo-symbiotic relationships has been highly studied in the tropical reef-forming corals but overlooked in less charismatic groups such as solar-powered sacoglossan sea slugs. These organisms display one of the most puzzling symbiotic features observed in the animal kingdom, i.e., their mollusk-plastid association, which enables them to retain photosynthetic active chloroplasts (i.e., kleptoplasts) retrieved from their algae feed sources. Here we analyze the impact of thermal stress (+4°C) and high pCO2 conditions (ΔpH = 0.4) in survival, photophysiology (i.e., bleaching, photosynthetic efficiency, and metabolism) and stress defense mechanisms (i.e., heat shock and antioxidant response) of solar-powered sacoglossan sea slugs, from tropical (Elysia crispata) and temperate (E. viridis) environments. High temperature was the main factor affecting the survival of both species, while pH only affected the survival of the temperate model. The photobiology of E. viridis remained stable under the combined scenario, while photoinhibition was observed for E. crispata under high temperature and high pCO2. In fact, bleaching was observed within all tropical specimens exposed to warming (but not in the temperate ones), which constitutes the first report where the incidence of bleaching in tropical animals hosting photosynthetic symbionts, other than corals, occurs. Yet, the expulsion of kleptoplasts by the tropical sea slug, allied with metabolic depression, constituted a physiological response that did not imply signs of vulnerability (i.e., mortality) in the host itself. Although the temperate species revealed greater heat shock and antioxidant enzyme response to environmental stress, we argue that the tropical (stenotherm) sea slug species may display a greater scope for acclimatization than the temperate (eurytherm) sea slug. E. crispata may exhibit increased capacity for phenotypic plasticity by increasing fitness in a much narrower thermal niche (minimizing maintenance costs), which ultimately may allow to face severe environmental conditions more effectively than its temperate generalist counterpart (E. viridis)

Os efeitos das alterações climáticas na fisiologia e fotobiologia das lesmas do mar fotossintéticas

Doutoramento em BiologiaThe vulnerability of marine photosynthetic symbioses to climate-driven changes has deserved particular attention in recent years. However, while there is an increasing number of studies on emblematic species such as symbiotic corals, little is known about less charismatic groups such as solar-powered sea slugs. These organisms display one of the most puzzling features observed in the animal kingdom: the mollusc-plastid association, which results from their ability to retain photosynthetically active chloroplasts (kleptoplasts) “stolen” from their algal food sources. Given their peculiar biology, sea slugs have stood out as tool organisms for academic research on photobiology, biomedical studies and bioprospecting of new marine drugs, becoming also desired critters in the marine aquarium trade. In order to provide an overview of state-of-the-art on our knowledge on these fascinating organisms, and lay down the foundations for climate change research, the biological and ecological features of the mollusc-plastid association were reviewed and optimal culture conditions for their different life stages were identified. The impact of ocean acidification and warming was evaluated on early stages and adults of temperate (Elysia viridis) and tropical (Elysia clarki) sea slugs. In this context, new methodological approaches were developed to non-invasively assess the photophysiology of kleptoplasts under future ocean conditions. Our results have shown that acidification and warming may impact several biological features of solar-powered sea slugs, including survival, reproductive success, growth, incidence of deformities, kleptoplasts photosynthetic efficiency, metabolism, heat shock and antioxidant responses. However, sea slug tolerance to future ocean conditions was shown to be species-specific. The temperate sea slug E. viridis, in spite of their low survival, presented efficient heat shock and antioxidant defence mechanisms and high rates of photosynthesis and respiration when exposed to acidification and warming, suggesting the existence of a more tolerant mollusc-kleptoplast complex and capacity to cope with future scenarios. In contrast, the tropical sea slug E. clarki showed to be quite vulnerable to future ocean conditions. The reduced capacity or lack of mechanisms to deal with environmental stress may, in part, explain the metabolic depression of the holobiont and the reduced photosynthetic efficiency of kleptoplasts, leading to bleaching and a lower survival. This work is the first reporting the occurrence of bleaching under climate change in other photosynthetic symbiosis than the cnidarian-dinoflagellate association. These results have broad implications and may help us to anticipate potential negative impacts on the recruitment of solar-powered sea slugs in the oceans of tomorrow. However, it is worth noting that solar-powered sea slugs may have time and evolutionary opportunities to adapt to future ocean conditions.A vulnerabilidade das simbioses fotossintéticas marinhas face às alterações climáticas tem recebido particular atenção nos últimos anos. Porém, enquanto existe um número crescente de estudos para as espécies emblemáticas, como os corais, pouco se sabe acerca dos grupos menos carismáticos como as lesmas do mar “movidas a energia solar”. Estes organismos possuem uma das particularidades mais intrigantes do reino animal: uma associação molusco-plasto, que resulta da sua capacidade de reter cloroplastos fotossinteticamente ativos (cleptoplastos) “roubados” às algas de que se alimentam. Dada a sua biologia peculiar, as lesmas do mar destacaram-se nos últimos anos como organismo “ferramenta” na investigação da fotobiologia, modelo nos estudos biomédicos e de bioprospeção de novos compostos marinhos, tornando-se ainda pretendidas para o comercio da aquariofilia marinha. Por forma a apresentar uma visão global acerca do conhecimento destes organismos fascinantes e estabelecer critérios para a investigação sobre as alterações climáticas, as características biológicas e ecológicas da associação molusco-plasto foram revistas e ainda identificadas as condições ótimas de cultivo para diferentes fases do seu ciclo de vida. O impacto da acidificação e o aquecimento dos oceanos foi avaliado nos estágios iniciais do desenvolvimento e nos adultos da lesma do mar temperada (Elysia viridis) e na tropical (Elysia clarki). Neste contexto, novas abordagens metodológicas foram desenvolvidas por forma a aceder de forma não invasiva à foto-fisiologia dos cleptoplastos de acordo com as futuras condições do oceano. Os resultados mostraram que a acidificação e o aquecimento do oceano podem influenciar as características biológicas das lesmas do mar “movidas a energia solar”, incluindo a sobrevivência, sucesso reprodutivo, crescimento, incidência de deformações, eficiência fotossintética dos cleptoplastos, metabolismo, e as respostas contra o choque térmico e de ação antioxidante. Contudo, a tolerância das lesmas do mar às condições futuras do oceano revelou ser especifica de cada espécie. A lesma do mar temperada E. viridis, apesar da baixa sobrevivência, apresentou mecanismos eficientes contra o choque térmico, defesa antioxidante e elevadas taxas de fotossíntese e respiração quando exposta à acidificação e ao aquecimento, sugerindo um complexo molusco-cleptoplasto mais tolerante e capacidade em lidar contra os cenários futuros. Por outro lado, a lesma do mar tropical E. clarki mostrou ser vulnerável às condições futuras do oceano. A reduzida capacidade e ausência de mecanismos para lidar com o stress ambiental pode, em parte, explicar a depressão metabólica do holobionte e a reduzida eficiência fotossintética dos cleptoplastos, que levaram ao branqueamento das lesmas do mar e a reduzida sobrevivência. Este trabalho é o primeiro a reportar a ocorrência de branqueamento em circunstâncias de alterações climáticas noutras simbioses marinhas que não as associações cnidário-dinoflagelado. Estes resultados têm amplas implicações e podem ajudar a antecipar os possíveis impactos negativos no recrutamento das lesmas do mar “movidas a energia solar” nos oceanos de amanhã. Contudo, é importante notar que as lesmas do mar “movidas a energia solar” poderão ter tempo e oportunidades evolutivas de adaptação às condições do futuro oceano

Anesthetizing solar-powered sea slugs for photobiological studies

Photosynthetic sea slugs have the ability to "steal" chloroplasts (kleptoplasts) from marine macroalgae and keep them structurally intact and physiologically functional. The photosynthetic activity of these symbioses has been assessed using pulse amplitude modulated (PAM) fluorometry. However, the movement of these sacoglossan slugs can impair specific photobiological studies on kleptoplasts. Thus, immobilizing sacoglossan slugs while not interfering with the photosynthetic activity would be a methodological advance for research in this field. We evaluated the effect of two anesthetics, eugenol and MS-222, on the photosynthetic activity of kleptoplasts and on the behavior of the kleptoplasts-bearing slug Elysia viridis. Anesthetics promoted relaxation of sea slug muscle with no touch reaction in about 6 min. Sea slugs immobilized for 120 min completely recovered after anesthetic removal. No significant differences were found on photosynthetic parameters measured immediately (0-1 min) after immobilization. The effective quantum yield of photosystem II of E. viridis after 120 min of immobilization was significantly decreased by 12% in the MS-222 treatment, while eugenol promoted no significant effect. Photosynthetic activity assessed by rapid light-response curves (RLC) of relative electron transport rates (rETR) revealed a significant decrease in both initial response to light (-34%) and maximum rETR (rETR(m)) (-60%), after 120 min of immobilization using MS-222. After 120 min of immobilization with eugenol, the initial response to light significantly decreased 15% and rETR(m) decreased 27%. We conclude that, whenever photobiological studies employing PAM fluorometry require immobilization of photosynthetic sea slugs, eugenol can be used as a powerful anesthetic with little impact on the photosynthetic activity of kleptoplasts.publishe

Facultative secondary lecithotrophy in the megalopa of the shrimp Lysmata seticaudata (Risso, 1816) (Decapoda : Hippolytidae) under laboratory conditions

Certain decapod crustaceans can catabolize internal reserves to undergo partial or full larval development. This feature is termed secondary lecithotrophy, if energy used results from plankton derived organic matter accumulated Ig earlier larval stages. The present work reports the ability of Lysmata seticaudata megalopa to moll to the first juvenile stage in the absence of food. Unlike previous records of secondary lecithotrophy displayed by nonfeeding last larval stages of hermit crabs and spiny lobsters, the megalopa of L. seticaudata retains its feeding capacity. This is the first time such a feature has been reported in decapods, and the term facultative secondary lecithotrophy is proposed. The build up of energy reserves continues during the last zoeal stage of L. seticaudata, with starved zoea IX failing to molt to megalopa. Energy reserves that enable starved megalopa to molt to juvenile seem to be partially depleted, with starved juveniles produced either from, starved or fed megalopae being unable to molt to the next juvenile stage. The longer resistance of starved juveniles produced from fed megalopae (nine days), compared to that of starved juveniles produced from starved megalopae (five days), indicates that some energy reserves may pass to juvenile, not being totally depleted at metamorphosis.info:eu-repo/semantics/publishedVersio

Skeletal quality in Senegalese sole: characterization of fish resulting from environmental and nutritional trials

The Senegalese sole (Solea senegalensis) is characteristic from southern Europe and Mediterranean. It has recently been adapted for aquaculture production since it is well accepted by consumers and reaches high commercial values. After the initial description of the ontogenic events of skeletogenesis, systematic evaluation of the incidence of skeletal malformations by several groups revealed high levels of skeletal deformities reaching up to 90% of the population

Marine microorganism-invertebrate assemblages: perspectives to solve the "supply problem" in the initial steps of drug discovery

The chemical diversity associated with marine natural products (MNP) is unanimously acknowledged as the "blue gold" in the urgent quest for new drugs. Consequently, a significant increase in the discovery of MNP published in the literature has been observed in the past decades, particularly from marine invertebrates. However, it remains unclear whether target metabolites originate from the marine invertebrates themselves or from their microbial symbionts. This issue underlines critical challenges associated with the lack of biomass required to supply the early stages of the drug discovery pipeline. The present review discusses potential solutions for such challenges, with particular emphasis on innovative approaches to culture invertebrate holobionts (microorganism-invertebrate assemblages) through in toto aquaculture, together with methods for the discovery and initial production of bioactive compounds from these microbial symbionts

Marine Objects Recognition Using Convolutional Neural Networks

One of the challenges of maritime affairs is automatic object recognition from aerial imagery. This can be achieved by utilizing a Convolutional Neural Network (CNN) based algorithm. For purposes of these research a dataset of 5608 marine object images is collected by using Google satellite imagery and Google Image Search. The dataset is divided in two main classes ("Vessels" and "Other objects") and each class is divided into four sub-classes ("Vessels" sub-classes are "Cargo ships", "Cruise ships", "War ships" and "Boats", while "Other objects" sub-classes are "Waves", "Marine animals", “Garbage patches" and "Oil spills"). For recognition of marine objects, an algorithm constructed with three CNNs is proposed. The first CNN for classification on the main classes achieves accuracy of 92.37 %. The CNN used for vessels recognition achieves accuracies of 94.12 % for cargo ships recognition, 98.82 % for cruise ships recognition, 97.64 % for war ships recognition and 95.29 % for boats recognition. The CNN used for recognition of other objects achieves accuracies of 88.56 % for waves and marine animals recognition, 96.92 % for garbage patches recognition and 89.21 % for oil spills recognition. This research has shown that CNN is appropriate artificial intelligence (AI) method for marine object recognition from aerial imagery

Effect of dietary vitamin K supplementation on skeletal development of Danio rerio

Nutritional imbalances affecting bone development have been implicated in the incidence of skeletal deformities, which are acknowledged to constitute one of the major constrains in the production of high quality fish. Several studies have focused on the identification of causes of deformities and associated them to factors such as rearing environment, nutrition and genetics. Among these, larval nutrition at first feeding is one of the key parameters affecting skeletogenesis during early development. Vitamin K (VK) is a liposoluble vitamin classically involved in blood coagulation, and until recently largely disregarded in aquaculture nutrition

Nudibranchs out of water: long-term temporal variations in the abundance of two Dendrodoris species under emersion

Abstract The sudden appearance and disappearance of nudibranchs in intertidal areas have puzzled researchers all over the world, giving rise to a great diversity of theories to explain it. Here we conducted a five-year survey to evaluate seasonal changes in the abundance of Dendrodoris herytra and D. grandiflora in the Sado estuary (Portugal) and to explore a possible relationship with environmental factors such as temperature, salinity, turbidity and dissolved oxygen. Moreover, we report, for the first time, the capacity of Dendrodoris nudibranchs to tolerate emersion (unhidden and completely exposed to sun exposure) during low tides. Our results showed that both species consistently started to appear emerged in March, reaching a peak abundance between April and May, and completely disappearing in July. In both species, this temporal trend was significantly associated with water temperature, turbidity, and dissolved oxygen, but not with salinity. We argue that the sudden appearance and disappearance of these nudibranchs in intertidal areas may result from a seasonal horizontal movement of adult nudibranchs from subtidal areas to mate in intertidal areas during spring, when phytoplankton production is enhanced and planktotrophic larvae may benefit from greater food availability