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- Avaliação de parâmetros de cultivo de Lysmata debelius Bruce, 1983 ao longo do desenvolvimento larvar e juvenilPublication . Salgado, Daniel Francisco; Leandro, Sérgio Miguel Franco Martins; Marques, Sónia Cristina FerreiraA presente dissertação teve como principal objetivo completar o ciclo de vida do camarão-de-fogo, de Lysmata debelius Bruce, 1983, em condições controladas de cativeiro, contribuindo para a sua domesticação e para o avanço da aquacultura ornamental. Para tal, foram definidos três eixos centrais de investigação: determinar o período até à obtenção de indivíduos com tamanho comercial, avaliar a influência da densidade de cultivo e da luz LED azul e branco (azul: 450-470nm e branco: 450-700nm) na sobrevivência e no assentamento larvar. Estes fatores são considerados determinantes para a definição de protocolos de cultivo eficientes e sustentáveis. Os resultados demonstraram que a sobrevivência larvar de Lysmata debelius foi fortemente influenciada pela densidade de cultivo, com melhores valores registados nas densidades mais baixas (90–140 larvas L-1. A taxa de assentamento não revelou diferenças estatisticamente significativas entre tratamentos. O tempo até ao primeiro assentamento foi mais curto nos ensaios sem luz (81,67 ± 2,31 dias), em comparação com aqueles conduzidos sob luz LED azul e branco (89,67–93,33 dias), embora sem diferenças estatisticamente significativas. Por outro lado, o tempo médio total até ao assentamento mostrou diferenças estatisticamente significativas na ausência de luz, situando-se entre 86,67 e 91,18 dias, face a 93,50–96,82 dias em presença de luz, sem efeito relevante da densidade. Finalmente, ao integrar as fases larvar e juvenil, estimou-se que o período total desde a desova até às dimensões do tamanho comercial (3 cm), variou entre 194 e 202 dias. Estes resultados, fornecem uma base sólida para a compreensão da biologia larvar de L. debelius, fundamental para a otimização dos protocolos de cultivo desta espécie e reforçam a necessidade de considerar múltiplos fatores ambientais e de manejo no desenho de sistemas produtivos. Do ponto de vista prático, esta investigação confirmou a viabilidade da produção sustentável desta espécie, abrindo caminho para reduzir a pressão sobre populações selvagens e responder à crescente procura do mercado. A consolidação de protocolos larvares e reprodutivos representa um passo essencial para a expansão da aquacultura ornamental, promovendo práticas mais responsáveis e ambientalmente sustentáveis, resultando numa menor dependência de exemplares capturados em populações naturais. Em forma conclusiva, este trabalho estabelece as bases para o cultivo controlado de Lysmata debelius, representando um contributo científico e aplicado relevante para a sua domesticação e para a consolidação da aquacultura ornamental como setor sustentável e inovador.
- Characterization of Selected Wild Mediterranean Fruits and Comparative Efficacy as Inhibitors of Oxidative Reactions in Emulsified Raw Pork Burger PattiesPublication . Ganhão, Rui; Estévez, Mario; Kylli, Petri; Heinonen, Marina; Morcuende, DavidIn the present study, water, ethanolic, and methanolic extracts from seven selected wild fruits originally from the Mediterranean area, namely, strawberry tree (Arbutus unedo L., AU), azarole (Crataegus azarolus L., CA), common hawthorn (Crataegus monogyna L., CM), blackthorn (Prunus spinosa L., PS), dog rose (Rosa canina L., RC), elm-leaf blackberry (Rubus ulmifolius Schott, RU), and rowan (Sorbus aucuparia L., SA), were analyzed for the total amount and profile of phenolic compounds and for the in vitro antioxidant activity against the DPPH and ABTS radicals (study 1). The seven fruits showed different chemical compositions, which consequently led to different antioxidant potentials. Among the seven fruits initially analyzed, AU, CM, RC, and RU had the highest amount of phenolic compounds and displayed the greatest antioxidant activity in vitro. Extracts from these four fruits were tested as inhibitors of lipid oxidation in raw pork burger patties subjected to refrigerated storage at 2 °C for 12 days (study 2). The quantitative measurements of thiobarbituric acid reactive substances (TBA-RS), hexanal content, and color stability were used as indicators of oxidative reactions. The four selected fruits displayed intense antioxidant activity against lipid oxidation, which highlights the potential usage of these fruits as ingredients for the manufacture of healthy meat products. Among them, RC and AU were particularly efficient as their protective effect against lipid oxidation was more intense than that displayed by quercetin (230 mg/kg of burger patty).
- Diel vertical behavior of Copepoda community (naupliar, copepodites and adults) at the boundary of a temperate estuary and coastal watersPublication . Gonçalves, A.M.M.; Pardal, M.A.; Marques, S.C.; S. Mendes; M.J. Fernández-Gómez; M.P. Galindo-Villardón; U.M. AzeiteiroDespite a growing interest in diel vertical migration as a research topic, there are few studies in southern European marine coastal systems. This study determined the main structuring hydrological and physical factors at different temporal scales in copepod assemblage distribution patterns. Seasonal, tidal, lunar and diel vertical migrations accomplished by horizontal movements were examined on the main copepod fraction of the Mondego estuary, Portugal. Seasonal samples were conducted hourly at the mouth of the estuary, during diel cycles (25h), both over neap and spring tides, at the bottom and surface, using a 63μm and 335μm mesh size nets. Simultaneously, four sites inside the estuary were sampled during flood tide to evaluate and compare copepods species' distribution along the estuary. Species life cycles were also categorized. Spring-spring tide best expresses the stable part of copepod-environment dynamics. Acartia tonsa and Oithona nana were distributed mainly at the bottom during ebb tides. A clear resident estuarine performance was noticeable in O.nana proving the estuarine preferences of the species. Neritic species showed preferences by saline waters, whereas the resident species were found mainly at estuarine areas. Copepodites stages showed a similar distribution pattern as estuarine species, avoiding leaving the estuary. In contrast nauplii and Oithona plumifera showed higher densities at surface flood tides. Indeed, vertical migrations accomplished by horizontal movements were mainly influenced by depth and tidal cycles, whereas day and night were not ecologically significant.
- An empirical comparison of Canonical Correspondence Analysis and STATICO in the identification of spatio-temporal ecological relationshipsPublication . Mendes, Susana; Fernández-Gómez, M. José; Pereira, Mário Jorge; Azeiteiro, Ulisses Miranda; Galindo-Villardón, M. PurificaciónThe wide-ranging and rapidly evolving nature of ecological studies mean that it is not possible to cover all existing and emerging techniques for analyzing multivariate data. However, two important methods enticed many followers: the Canonical Correspondence Analysis (CCA) and the STATICO analysis. Despite the particular characteristics of each, they have similarities and differences, which when analyzed properly, can, together, provide important complementary results to those that are usually exploited by researchers. If on one hand, the use of CCA is completely generalized and implemented, solving many problems formulated by ecologists, on the other hand, this method has some weaknesses mainly caused by the imposition of the number of variables that is required to be applied (much higher in comparison with samples). Also, the STATICO method has no such restrictions, but requires that the number of variables (species or environment) is the same in each time or space.Yet, the STATICO method presents information that can be more detailed since it allows visualizing the variability within groups (either in time or space). In this study, the data needed for implementing these methods are sketched, as well as the comparison is made showing the advantages and disadvantages of each method. The treated ecological data are a sequence of pairs of ecological tables, where species abundances and environmental variables are measured at different, specified locations, over the course of time.
- Estudo comparativo do perfil químico e das bioatividades de três macroalgas marinhas em diferentes contextos ecológicosPublication . Matias, Margarida Henriques; Mouga, Teresa Margarida Lopes da Silva; Afonso, Clélia Paulete Correia NevesEsta dissertação teve como principal objetivo comparar três espécies de macroalgas – Gracilaria gracilis, Sargassum muticum e Ulva sp. – colhidas em épocas distintas do ano e em locais distintos da costa portuguesa, através da caraterização do perfil bioquímico e das bioatividades (antimicrobianas, antioxidantes e bioestimulantes). A caraterização ecológica dos locais demonstrou condições ambientais contrastantes: a Figueira da Foz apresenta forte influência marítima e alguma fluvial, com águas relativamente frias; a Lagoa de Óbidos é marcada por águas calmas e elevada variabilidade físico-química; e Peniche carateriza-se pelas praias rochosas, sujeitas a forte agitação marítima. Estas diferenças refletem-se sobretudo na salinidade e no oxigénio dissolvido, condicionando a fisiologia e a composição bioquímica das algas. Em diferentes análises observaram-se diferenças significativas entre espécies e também entre locais, enquanto a sazonalidade mostrou menor impacto nos resultados. Os resultados mostraram que o teor de humidade é superior nas amostras colhidas em setembro/novembro, indicando um efeito sazonal. No teor de cinzas, G. gracilis possui os teores mais baixos, sem diferenças significativas entre épocas e locais. Quanto ao conteúdo mineral, destaca-se o cálcio, variando entre 1,91 e 17,91 mg/g, enquanto o arsénio excede os limites regulamentados, em todas as amostras. Além disso, a G. gracilis apresentou o maior teor de hidratos de carbono, enquanto o teor proteico variou entre espécies, com a Ulva sp. de Buarcos de março (UBM) a obter o valor máximo (4,78%). Relativamente à matéria gorda total, a Ulva sp., registou o valor mais baixo (0,52%), enquanto o S. muticum apresentou o valor máximo (3,23%), exibindo predominantemente ácido palmítico (C16:0) e ácido oleico (C18:1 n9 cis). O rácio ómega-6/ómega-3, por sua vez, é superior a 1 nas amostras de S. muticum (entre 1,9 e 2,73) e maioritariamente inferior a 1 na Ulva sp., exceto na UBM. Na análise dos pigmentos fotossintéticos, a clorofila a é o pigmento mais abundante, atingindo 8,45 mg/g em S. muticum. Adicionalmente, a fucoxantina variou entre 0,77 e 1,87 mg/g em S. muticum e a ficoeritrina-R oscilou entre 0,047 e 0,549 mg/g em G. gracilis. Também se verificou que a abundância de pigmentos é fortemente influenciada pelo local de recolha. Os extratos hidroetanólicos não exibiram atividade antimicrobiana relevante, mas demonstraram forte atividade antioxidante, destacando-se a UBM (93,85% de inibição no DPPH e 564,16 μmol Fe/g no FRAP). No QTP, por sua vez, destacou-se o S. muticum de Óbidos em março, com uma concentração de 38,42 mg GAE/g. As frações residuais dos extratos revelaram um elevado potencial bioestimulante nas sementes de alface e tomate, sendo que, relativamente ao crescimento, destaca-se a Ulva sp.. Estas descobertas evidenciam que a composição bioquímica e as bioatividades das espécies em estudo são influenciadas pela espécie, pelo local e pela sazonalidade, realçando o seu potencial como recursos de valor acrescentado na área nutricional, agronómico e biotecnológico.
- Feeding habits of Solea senegalensis in earthen ponds in Sado estuaryPublication . Castelo Branco, Maria Ana; Arruda, Marco A.; Gamito, SofiaThe senegale sole, Solea senegalensis Kaup, 1858, is a commercially valuable fish and it is beginning to be cultured in a semi-intensive way in fish farms in southern European countries. The present study was initiated to investigate the diet of S. senegalensis under semi-extensive conditions. The feeding habits of sole were studied in two earthen ponds of a fish farm in the Sado estuary. In one earthen pond, artificial fish ration was given. S. senegalensis feeds on few prey items, its diet is mainly composed of insect larvae (Chironomus salinarus) and polychaeta (Hediste diversicolor). The diet composition of this species suggests feeding specialization, by consuming mainly annelids and insect larvae and by avoiding other items, extremely abundant in the environment, such as gastropods. In the water reservoir where ration was given, some fish consumed simultaneously benthic organism together with ration. However, benthic organisms seem to be the most important component of S. senegalensis diet.
- Immobilized heterologous Rhizopus oryzae lipase: A feasible biocatalyst for the production of human milk fat substitutesPublication . Tecelão, Carla; Guillén, Marina; Valero, Francisco; Ferreira-Dias, SuzanaThis work aims at evaluating the potentialities of a heterologous Rhizopus oryzae lipase (rROL) as a feasible biocatalyst, to be used as an alternative to commercial lipases, for the synthesis of Human Milk Fat Substitutes (HMFS). This enzyme was immobilized in three different supports (Accurel® MP 1000, Eupergit® C and Lewatit® VP OC 1600) and tested as catalysts for the acidolysis between tripalmitin and oleic acid, batchwise, at 60 ◦C, in solvent-free medium. The highest molar incorporations of oleic acid in the triacylglycerols were achieved with rROL in Lewatit® VP OC 1600 and Accurel® MP 1000, although the highest immobilization yields were observed with Eupergit® C. Quasi-equilibrium was attained after 6 h or 12 h reaction, with about 30 mol.% and 22 mol.% of oleic acid incorporation, when rROL immobilized in Lewatit and Accurel were used, respectively. Also, 23 h batch operational stability tests were performed: half-life times (t1/2) of 34.5 h and 64.0 h were achieved for rROL immobilized in Accurel® MP 1000 and in Lewatit® VP OC 1600, respectively. An important increase in the operational stability was observed for rROL immobilized in Lewatit after rehydration at the end of each batch (t1/2 = 202 h). Thus, the loss of activity may be explained by a progressive dehydration occurring along the reaction.
- Improved specific productivity in cephalexin synthesis by immobilized PGA in silica magnetic micro‐particlesPublication . Bernardino, Susana M. S. A.; Fernandes, Pedro; Fonseca, Luís P.There is a marked trend in pharmaceutical industry towards the replacement of classical organic methods by "green" alternatives that minimize or eliminate the generation of waste and avoid, where possible, the use of toxic and/or hazardous reagents and solvents. In this work the kinetically controlled synthesis of cephalexin by soluble and penicillin G acylase immobilized in sol-gel micro-particles with magnetic properties was performed in aqueous media with PGME and 7-ADCA as substrates, at different concentrations of substrate, temperature, pH, enzyme to substrate ratio and acyl donor to nucleophile ratio. Excess acyl donor had a strong effect on cephalexin productivity. A PGME/7-ADCA ratio of 3 was considered optimum. A maximum specific productivity of 5.9 mmol h-1gbiocatalyst-1 at 160 mM 7-ADCA, 480 mM PGME and low enzyme to substrate ratio at 32.5 U mmol-1 7-ADCA was obtained with immobilized PGA in full aqueous medium, suggesting that diffusional limitations were minimized when compared with other commercial biocatalysts. A half-life of 133 h for the immobilized biocatalyst was estimated during cephalexin synthesis in the presence of 100 mM 7-ADCA and 300 mM PGME, in 50 mM Tris/HCl at pH 7.2 and 14°C. These results compare quite favorably with those previously reported for the kinetically controlled synthesis of cephalexin.
- Is mobile phone radiation genotoxic? An analysis of micronucleus frequency in exfoliated buccal cellsPublication . Oliveira, F. M. de; Carmona, A. M.; Ladeira, C.Electromagnetic fields (EMF) are classified as “possibly carcinogenic” by the International Agency for Research on Cancer (IARC). Some publications have reported associations between EMF exposure and DNA damage, but many other studies contradict such findings. Cytomorphological changes, such as micronuclei (MN), indicative of genomic damage, are biomarkers of genotoxicity. To test whether mobile phone-associated EMF exposure affects the MN frequency in exfoliated buccal cells, we obtained cells smears from the left and right inner cheeks of healthy mobile phone users, aged 18–30 (n =86), who also completed a characterization survey. MN frequencies were tested for potential confounding factors and for duration of phone use and preferential side of mobile phone use. No relationship was observed between MN frequency and duration of mobile phone use in daily calls. Cells ipsilateral to mobile phone use did not present a statistically significantly higher MN frequency, compared to cells contralateral to exposure. A highly statistically significant (p < 0.0001) increase in MN frequency was found in subjects reporting regular exposure to genotoxic agents. Therefore, our results suggest that mobile phone-associated EMF do not to induce MN formation in buccal cells at the observed exposure levels.
- Lipid composition and nutritional quality of intramuscular fat in Charneca-PDO beefPublication . Pestana, José M; Costa, Ana S. H.; Alfaia, Cristina M.; Costa, Paulo; Martins, Susana V.; Alves, Susana P.; Bessa, Rui J. B.; Prates, José A. M.This paper characterizes the intramuscular fat from longissimus lumborum (LL, relatively red) and semitendinous (ST, relatively white) muscles of Charneca beef from young bulls reared according to the protected designation of origin (PDO) specifications. The content of total lipids, total cholesterol, α-tocopherol and β-carotene, as well as the fatty acid composition, including the isomeric distribution of conjugated linoleic acid (CLA), was assessed. Charneca young bulls (n = 10) were raised on a semi-extensive production system, in which animals fed pasture plus concentrate during 15 months. The ST muscle was leaner and had higher percentages of PUFA, in contrast to the LL muscle, which presented higher percentages of SFA and MUFA. Thus, the ST muscle had a higher PUFA/SFA ratio than the LL muscle, although the ratio values of both muscles were inside the recommended figures for the human diet. In contrast, the contents of CLA isomers, total cholesterol, α-tocopherol and β-carotene, as well as the n-6/n-3 ratio, were not influenced by muscle type, thus suggesting no carcass variation for these compounds. In both muscles, the n-6/n-3 ratios were slightly above the dietary guideline for human diet, and the contents of α-tocopherol were very high, indicating a good lipid stability of Charneca-PDO beef. Overall, the results suggest that intramuscular fat of Charneca-PDO beef has good human health-related parameters, with small carcass variation, since the PUFA/SFA and n-6/n-3 ratio values are inside or very close to the recommended figures for the human diet, and the content of α-tocopherol is very high.
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