Browsing by Issue Date, starting with "2018"
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- Population genetics of the bigeye thresher shark Alopias superciliosus in the Atlantic and Indian Oceans: implications for conservationPublication . Morales, Millke Jasmine Arminini; Mendonça, Fernando Fernandes; Magalhães, Carolina Oliveira; Oliveira, Claudio; Coelho, Rui; Santos, Miguel Neves; Cruz, Vanessa Paes; Piercy, Andrew; Burgess, George; Hazin, Fabio Vieira; Foresti, FaustoPopulation structure and genetic connectivity are pivotal contributions to the establishment of conservation strategies for fisheries management, in particular for highly migratory species that are affected by commercial fisheries. This study used partial sequences of mitochondrial DNA control region to determine the genetic structure of the bigeye thresher shark Alopias superciliosus in the Atlantic and Indian Oceans. A total of 858 base pairs of mtDNA CR from 228 individuals were analyzed. The resulting nucleotide diversity (π) was 0.0011 ± 0.0008 and the haplotype diversity (h) was 0.127 ± 0.030. These are the lowest diversities registered in elasmobranchs with this genetic marker. Two genetically distinct lineages were identified, one of them represented by 3.9% of the analyzed individuals and none restricted to any particular area. Simulated scenarios of population structure, tested with AMOVA and pairwise ΦST did not result in significant values indicating high connectivity among all sampled groups. The absence of population structure, even between Atlantic and Indian Oceans, corroborates the high dispersal ability of this species. The low genetic diversity detected in this species and the identification of two historical lineages occurring in sympatry, one represented by a very small number of individuals, should be considered in the conservation efforts and management plans of A. superciliosus.
- Retábulos devocionais às Almas do PurgatórioPublication . Lameira, FranciscoNos países católicos Contra-reformistas, nos séculos XVII e XVIII, os retábulos tiveram uma enorme aceitação social, sem paralelo quer com a época anterior quer posterior. Lembramos que os retábulos foram os principais equipamentos litúrgicos e artísticos usados na larga maioria das situações no interior dos templos e pontualmente no exterior, neste último caso nalgumas igrejas de peregrinação e em cemitérios. A existência de vários altares num mesmo templo, cada um deles com o seu próprio orago e administrado por uma entidade diferente ou não, possibilitava a celebração simultânea de dois ou mais ofícios religiosos.
- Molecular and cellular effects of temperature in oysters Crassostrea brasiliana exposed to phenanthrenePublication . Lima, Daína; Zacchi, Flávia Lucena; Mattos, Jacó Joaquim; Flores-Nunes, Fabrício; Gomes, Carlos Henrique Araújo de Miranda; de Mello, Álvaro Cavaler Pessoa; Siebert, Marília Nardelli; Piazza, Clei Endrigo; Taniguchi, Satie; Sasaki, Silvio Tarou; Bícego, Márcia Caruso; Bebianno, Maria João; de Almeida, Eduardo Alves; Bainy, Afonso Celso DiasExposure of aquatic organisms to polycyclic aromatic hydrocarbons (PAH), such as phenanthrene (PHE), may increase the production of reactive oxygen species (ROS) and cause changes in the biotransformation systems. In addition, changes in water temperature can cause adverse effects in the organisms. Estuarine species, like the oyster Crassostrea brasiliana, can adapt and tolerate temperature variation. To evaluate the influence of temperature on biological responses of C. brasiliana exposed to PHE, oysters were maintained at three temperatures (18, 24 and 32 °C) for 15 days and co-exposed afterwards to 100 μg.L-1 of PHE for 24 and 96 h. Levels of PHE in the water and oyster tissues were determined, respectively after 24 and 96 h. In addition, thermal stress, biotransformation and oxidative stress-related genes were analyzed in oyster gills, together with the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferases (GST) and levels of lipid peroxidation. Oyster accumulated significant levels of PHE. HSP70-like transcripts were affected by PHE exposure only at 32 °C. Transcript levels of cytochrome P450 isoforms (CYP2-like2 and CYP2AU1) were down-regulated in oysters exposed to PHE for 24 h at 32 °C. GSTΩ-like transcript levels were also down-regulated in the PHE-exposed group at 32 °C. After 96 h, CYP2-like2 transcripts were higher in the PHE exposed groups at 32 °C. Oysters kept at 18 °C showed higher levels of SOD-like transcripts, together with higher GST, GPx and G6PDH activities, associated to lower levels of lipoperoxidation. In general the biological responses evaluated were more affected by temperature, than by co-exposure to PHE.
- Do TEARS ao TEADI: atributos importantes de blogueiras de moda para seguidoresPublication . Gandra, Carla Fabrícia Abílio de Oliveira; Gosling, Marlusa de Sevilha; Vera, Luciana Alves Rodas; Vilela, Bruno de AlmeidaOs blogs de moda têm se destacado pelo poder de influenciar os seguidores e por modificar o estilo de vida e de consumo das pessoas. O objetivo deste estudo é verificar quais são os atributos importantes das blogueiras de moda que contribuem para a intenção das pessoas de continuarem seguindo os blogs. Nesse sentido, este estudo propõe um modelo teórico no intuito de avaliar a relação entre os atributos importantes de blogueiras de moda e a intenção das pessoas de continuarem seguindo os blogs. A partir da análise fatorial exploratória, foram identificados cinco fatores relevantes: Confiabilidade, Expertise, Atração Física, Similaridade e Difusão da Informação e Ideias. A análise de modelagem de equações estruturais revelou que as variáveis independentes “Difusão de Informação e Ideias, Similaridade e Atração Física” têm relação positiva direta com a intenção de continuar seguindo, enquanto a Confiabilidade, a Expertise e o Respeito não foram hipóteses suportadas no estudo.
- Change in the North Atlantic circulation associated with the mid-Pleistocene transitionPublication . Martin-Garcia, Gloria M.; Sierro, Francisco; Flores, José A.; Abrantes, FatimaThe southwestern Iberian margin is highly sensitive to changes in the distribution of North Atlantic currents and to the position of oceanic fronts. In this work, the evolution of oceanographic parameters from 812 to 530 ka (MIS20-MIS14) is studied based on the analysis of planktonic foraminifer assemblages from site IODP-U1385 (37 degrees 34.285' N, 10 degrees 7.562' W; 2585m b.s.l.). By comparing the obtained results with published records from other North Atlantic sites between 41 and 55 degrees N, basin-wide paleoceano-graphic conditions are reconstructed. Variations of assemblages dwelling in different water masses indicate a major change in the general North Atlantic circulation during MIS16, coinciding with the definite establishment of the 100 ky cyclicity associated with the mid-Pleistocene transition. At the surface, this change consisted in the redistribution of water masses, with the subsequent thermal variation, and occurred linked to the northwestward migration of the Arctic Front (AF), and the increase in the North Atlantic Deep Water (NADW) formation with respect to previous glacials. During glacials prior to MIS16, the NADW formation was very weak, which drastically slowed down the surface circulation; the AF was at a southerly position and the North Atlantic Current (NAC) diverted southeastwards, developing steep south-north, and east-west, thermal gradients and blocking the arrival of warm water, with associated moisture, to high latitudes. During MIS16, the increase in the meridional overturning circulation, in combination with the northwestward AF shift, allowed the arrival of the NAC to subpolar latitudes, multiplying the moisture availability for ice-sheet growth, which could have worked as a positive feedback to prolong the glacials towards 100 ky cycles.
- Transmídia e a ecologia hipercomplexa das mídia. Poética, linguagem e mediaçãoPublication . Santos, Marcelo MoreiraO presente relatório foi realizado no âmbito do pós-doutoramento de Marcelo Moreira Santos, feito no CIAC, Centro de Investigação em Artes e Comunicação da UAlg, entre 01 de Agosto de 2016 e 06 Janeiro de 2018. A presente pesquisa visa a analisar o fenômeno transmidiático à luz da semiótica de Charles S. Peirce em conjunção com as teorias sistêmicas desenvolvidas por Edgar Morin, Mário Bunge, Ilya Prigogine e Jorge Albuquerque Vieira.
- Towards assessing the resilience of complex coastal systems: examples from Ria Formosa (South Portugal)Publication . Kombiadou, Katerina; Matias, Ana; Carrasco, Rita; Ferreira, Oscar; Costas, S.; Vieira, G.The present paper contributes to assessing the resilience of a complex barrier island environment, namely of the Ria Formosa multi-inlet system in southern Portugal. The long-term morphologic evolution of four study areas during the last 60 years (1947 to 2014) is analysed based on aerial photographs, including the environments of oceanic and backbarrier beaches, dunes and salt marshes. The results show that each study area responded to external drivers (inlet stabilisation works, storms, etc.) differently, evolving in distinct patterns during the study period. All four study areas appear resilient to external pressures and/or forcing conditions, since they are either transforming (Barreta and Culatra islands), or adapting (Cabanas island and Cacela peninsula) or remaining stable at a near-equilibrium state (Tavira island). Based on the analysis of the multi-decadal evolution of the sites, four resilient barrier states are identified, related to the maturity and growth of the barrier. In the next stages, the research will focus on the relation between medium to short-term changes, aiming at understanding the response and feedbacks of the environments to specific drivers of change and relating them to resilience indicators.
- Modeling the influence of rutrophication and redox conditions on mercury cycling at the sediment-water interface in the Berre LagoonPublication . Pakhomova, Svetlana; Yakushev, Evgeniy; Protsenko, Elizaveta; Rigaud, Sylvain; Cossa, Daniel; Knoery, Joel; Couture, Raoul-Marie; Radakovitch, Olivier; Yakubov, Shamil; Krzeminska, Dominika; Newton, AliceThis study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(O)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast subjected to seasonal anoxia. The first scenario represents the conditions in the lagoon that are compared with experimental data. The four other scenarios were produced by varying the biological productivity, using low and high nutrient (N and P) concentrations, and by varying the redox conditions using different intensity of vertical mixing in the water column. The results of the simulation show that both oxidized and reduced sediments can accumulate Hg, but any shifts in redox conditions in bottom water and upper sediment layer lead to the release of Hg species into the water column. Eutrophication and/or restricted vertical mixing lead to reducing conditions and intensify MeHg formation in the sediment with periodic release to the water column. Oxygenation of an anoxic water body can lead to the appearance of Hg species in the water column and uptake by organisms, whereby Hg may enter into the food web. The comparison of studied scenarios shows that a well-oxygenated eutrophic system favors the conditions for Hg species bioaccumulation with a potential adverse effect on the ecosystem. The research is relevant to the UN Minimata convention, EU policies on water, environmental quality standards and Mercury in particular.
- State of the art of pricing policy in air transportation: network carriers vs. low-cost airlinesPublication . Wehner, Christian; López-Bonilla, Jesús Manuel; López-Bonilla, Luis Miguel; Santos, José António C.The modern air transport industry is highly competitive. To survive in the market, the implementation of a successful marketing strategy is fundamental. In particular, an effective pricing policy has become crucial for airlines to remain profitable. Correspondingly, the different types of airline in the market have also established very distinct pricing policies. The present study is based on a literature review and presents the state of the art of pricing policy in air transportation. The aim is to compare and discuss the pricing strategies of network carriers and low-cost airlines. Special attention is paid to Revenue Management, which is a very important management tool used by airlines to take advantage of the differences in willingness to pay of passengers. The pricing policy, however, depends on the overall business strategy of the airline. Results show many differences, resulting from the fact that these two types of airline are characterized by very different fundamental business models and, correspondingly, also target groups. Since network carriers and also low-cost airlines have adjusted their pricing strategies lately, these recent developments will be discussed as well. This paper adds to the knowledge of this topic because it presents the most up-to-date and complete study on pricing regarding network carriers vs. low-cost airlines.
- Analogues of centralizer subalgebras for fiat 2-categories and their 2-representationsPublication . Mackaay, Marco; Mazorchuk, Volodymyr; Miemietz, Vanessa; Zhang, XiaotingThe main result of this paper establishes a bijection between the set of equivalence classes of simple transitive 2-representations with a fixed apex J of a fiat 2-category C and the set of equivalence classes of faithful simple transitive 2-representations of the fiat 2-subquotient of C associated with a diagonal H-cell in J. As an application, we classify simple transitive 2-representations of various categories of Soergel bimodules, in particular, completing the classification in types B-3 and B-4.