Browsing by Issue Date, starting with "2019-12-02"
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- Ecological study of nudibranchs in the Armona biodiversity hotspotPublication . Hoett, Sandra; Duarte, Duarte; Gamito, SofiaSince the 1980s, scientific interest in nudibranch species has grown due to their potential in biotechnology and neurobiology. But only a limited number of ecological studies have been undertaken specifically on this mollusk group in a lagunary environment. This MSc thesis aims at assessing the nudibranch ecology of the Armona biodiversity hotspot in the Ria Formosa lagoon and at collecting information helpful to its conservation. The scope includes investigating the abundance of each species, which environment it prefers, its behaviour, biometrics and role in the trophic web as well as their relationship with the other benthos. In situ data acquisition during scientific diving forms the basis of the study. The diving survey took place during May 2018, a time of the year for which previous studies had typically observed higher densities of nudibranchs. Data gathered from 10 dives was dissimilar but consistent. Flabellina affinis was the most abundant species identified in the Armona hotspot during the survey. Whilst previous surveys pointed out to other species of nudibranchs in the Ria Formosa area, these findings could not be confirmed in May 2018. This leads to questions about migration and general behaviour patterns of the nudibranch. Determining the density of invertebrates other than nudibranchs, observing their behavior and recording their biometrics were secondary goals of this thesis. These tasks were performed through random quadrat sampling and should contribute to the knowledge of benthos inside the surveyed biodiversity patches. The Armona biodiversity hotspot or patch consists of sea urchins accumulating in the sandy bottom of the Ria Formosa and generating livable niches for a great number of organisms. This results in the creation of a specific community with unique features
- Muxama and other traditional food products obtained from tuna in south Portugal and Spain: review and future perspectivesPublication . Esteves, Eduardo; Aníbal, J.There is evidence that consumers perceive fish as healthy (Carlucci D et.al, Appetite 84:212–27,2015; Vanhonacker F et.al, Br Food J 115:508–25,2013; Verbeke W et.al, Public Health Nutr 8:422–9,2005.). Historically, the development of (traditional) processing techniques allowed for the preservation of excess quantities of fresh fish for storage or transport. Those technologies are not well documented and are being lost with the trend to urbanization and consumption of convenience, ready-to-eat food. In the so-called developed world, there is still a considerable demand for traditionally processed (sea)food products, wherein the raw material and the final product are of high value. Muxama or mojama is a traditional, highly valued food product prepared from dry-cured tuna loins that is a delicatessen in the southern Iberian Peninsula: Algarve (Portugal) and Andalucía, Murcia, Alicante, and Valencia (Spain). The tuna (mostly Thunnus obesus and T. albacares) loins are salted and dried following a typically artisanal process that incorporates empirical knowledge passed down numerous generations since at least the tenth century Common Era (Aníbal J and Esteves E, Muxama and estupeta: traditional food products obtained from tuna loins in South Portugal and Spain, Traditional food products 2016, Lindkvist KB et.al, Can Geogr-Géogr Can 52:105–20,2008, Gallart-Jornet L et.al, La salazón de pescado, una tradición en la dieta mediterránea [The salting of fish, a tradition in the Mediterranean diet] 2005.). The production process changed little over the years but is different among locations, even supporting distinct certifications. The stability of muxama derives from the reduced water activity. Furthermore, the drying method has secondary effects on flavor, color, and nutritional value of the product. In southern Portugal and Spain, muxama is the prime food product obtained from tuna at the end of the traditional quartering of tunas, named ronqueamento in Portugal or ronqueo in Spain. Other food products obtained from tuna include Estupeta, Mormos, Rabinhos, Faceiras and Orelhas, Ventresca, Tarantela and Sangacho, Espinheta, Tripa, Bucho, and Ovas. These products result from employing different manufacturing procedures and processes. In this paper, we tentatively describe the main features of the processing stages and traditional food products obtained from tuna produced in the southern Iberian Peninsula (Portugal and Spain) and discuss the interactions of knowledge systems and transmission of traditional knowledge regarding its production.
- Coupling shifts in the composition of coral tissue- and mucusassociated microbial communities to changes in coral host physiology and environmental fluctuationsPublication . Marchioro, Giulia Manso; Frade, Pedro R.; Engelen, Aschwin H.Understanding the drivers of microbiome variation in corals is crucial to better predict the effects of environmental pressures on coral holobionts and coral reef ecosystems. However, much remains to be understood about corals and the interactions they establish with microorganisms. My hypothesis is that the microbiome of the surface mucus layer (SML) is mainly influenced by environmental parameters due to its direct contact with the environment, whereas the tissue microbiome is more driven by the physiology of the coral host. Therefore, the aim of the present work is to distinguish the effect of the host’s intrinsic and environmental factors on the microbiome composition in different coral compartments (SML and tissue), and to identify possible overarching trends in the environmental sensitivity of distinct microbiomes within a coral holobiont. Using next-generation amplicon-sequencing of the 16S rRNA gene, the analyses showed that microbiomes of Acropora spp. differed significantly between compartments (SML versus tissue) and species (A. tenuis versus A. millepora), but also among sampling location and season. Seawater samples were characterized by dominance of members of the Synechococcaceae and Pelagibacteraceae. In Acropora spp., mucus microbiome was dominated by members of Flavobacteriaceae, Synechococcaceae, Rhodobacteraceae and Pelagibacteraceae families, while the tissue microbiome was dominated by the Endozoicimonaceae family. SML microbiomes of both coral hosts correlated best with environmental parameters as ammonium, total suspended solids, particulate organic carbon, number of raindays and nitrate/nitrite. However, the amount of influence from environmental parameters on the mucus (explaining 12-15% of variation) is relatively low as compared with the influence of those parameters on the seawater microbiome (explaining 49% of variation). In contrast, the tissue microbiomes of the two Acropora species showed distinct and species-specific responses to environmental and physiological parameters, suggesting host-specific modulation of the environmental drivers of the tissue microbiome.
- Aplicação de nanoemulsões na conservação de Pera ´Rocha´Publication . Antão, Rui Filipe Inácio; Antunes, Maria Dulce; Gago, Custódia Maria LuísA pera ‘Rocha’ é uma cultivar portuguesa de pera com características organoléticas únicas, destacando-se também pela sua capacidade de conservação. Esta variedade tem tendência ao aparecimento de desordens fisiológicas após armazenamento prolongado no frio, como o escaldão superficial. Após a proibição da difenilamina, o 1-metilciclopropeno (1-MCP) tem sido utilizado na conservação de pera ‘Rocha’ para prevenção do escaldão superficial do armazenamento, mas tem apresentado desvantagens, nomeadamente na progressão do amadurecimento dos frutos. Nanoemulsões contendo óleos essenciais têm revelado eficácia na conservação de produtos minimamente processados e outros, pela sua ação antimicrobiana e antioxidante e poderão ser usadas como alternativa ao 1-MCP. Neste trabalho foram testados 4 tratamentos com nanoemulsões contendo alginato e óleos essenciais citral (CI) e erva-príncipe (EP) em pera ‘Rocha’ armazenada a 0 ºC durante 6 meses, e foram efetuadas análises qualitativas aos frutos no momento da aplicação, 2, 4 e 6 meses após armazenamento, assim como após 7 dias em condições de prateleira (22 ºC). O controlo consistiu em frutos sem tratamento. Foram analisados a cor, firmeza, teor de sólidos solúveis, acidez titulável, perda de peso, extravasamento eletrolítico, escaldão superficial, acastanhamento interno, evolução microbiana e realizado um painel de provadores. Os tratamentos EP 1,25% e EP 2,5% obtiveram os resultados mais favoráveis quanto à evolução da maturação e prevenção do escaldão superficial, e as peras com o tratamento EP 1,25% tiveram a melhor aceitação geral nas provas organoléticas. Estes tratamentos exibiram melhorias na conservação de pera ‘Rocha’ no frio e podem servir de base em ensaios futuros para encontrar uma alternativa à utilização do 1-MCP nesta cultivar.
- Farmacorresistência a antiepiléticos e novas abordagens de tratamentoPublication . Saraiva, Hugo Daniel de Sousa; Serralheiro, AnaA epilepsia é um distúrbio neurológico comum que afeta, aproximadamente, 70 milhões de pessoas em todo o mundo. Apesar da recente introdução de novos fármacos antiepiléticos, cerca de um-terço dos doentes com epilepsia apresentam resistência à terapêutica, continuando a exibir crises. A indentificação precoce de doentes que se possam tornar refratários pode ajudar a direcioná-los para um tratamento não-farmacológico mais apropriado, mas a comlexidade por detrás dos padrões da epilepsia pode dificultar essa identificação. A hipótese do alvo e a hipótese do transportador são as teorias mais citadas que tentam explicar a epilepsia refratária, mas nenhuma teoria sozinha explica a base neurobiológica subjacente à farmacorresistência. Esta monografica resume evidências a favor e contra as principais hipóteses, incluindo a hipótese farmacocinética, hipótese da rede neural, hipótese da gravidade intrínseca, hipótese da variação genética, hipótese do alvo e hipótese do transportador. A discusão concentra-se, em grande parte na hipótese do transportador, onde os dados clínicos e exprimentais são discutidos sobre a superexpressão de transportadores de múltiplos fármacos, mecanismos de regulação positiva do transportador, polimorfismos dos transportadores e uso de inibidores do transportador. Por fim, são apresentadas prespetivas futuras para o aperfeiçoamento das hipóteses já existentes e o desenvolvimento de novas estratégias terapêuticas, orientadas pelo conhecimento atual sobre a epilepsia refratária.