Browsing by Issue Date, starting with "2016-01"
Now showing 1 - 10 of 60
Results Per Page
Sort Options
- Geodetic implications on block formation and geodynamic domains in the South Shetland Islands, Antarctic PeninsulaPublication . Berrocoso, M.; Fernandez-Ros, A.; Prates, Gonçalo; Garcia, A.; Kraus, S.The South Shetland Islands archipelago is dynamically complex due to its tectonic surroundings. Most islands are part of a formerly active volcanic arc, although Deception, Penguin and Bridgeman Islands, as well as several submarine volcanoes, are characterized by active back-arc volcanism. Geodetic benchmarks were deployed and the movement of the lithosphere to which they were fixed measured to provide geodynamic insight for the South Shetland Islands, Bransfield Basin and Antarctic Peninsula area based on surface deformation. These benchmarks' data add spatial and temporal coverage to previous results. The results reveal two different geodynamic patterns, each confined to a distinct part of the South Shetland Islands archipelago. The inferred absolute horizontal velocity vectors for the benchmarks in the northeastern part of the archipelago are consistent with the opening of the Bransfield Basin, while benchmark vectors in the southwestern part of the archipelago are similar to those of the benchmarks on the Antarctic Peninsula. In between, Snow, Deception and Livingston Islands represent a transition zone. In this area, the horizontal velocity vectors relative to the Antarctic plate shift northeastwards from N to NW. Furthermore, the South Shetland Islands benchmarks, except for that at Gibbs (Elephant) Islands, indicate subsidence, which might be a consequence of the slab roll-back at the South Shetland Trench. In contrast, the uplift revealed by the Antarctic Peninsula benchmarks suggests glacial isostatic adjustment after the Larson B ice-shelf breakup. (C) 2015 Elsevier B.V. All rights reserved.
- External control of the Drosophila melanogaster egg to imago development period by specific combinations of 3D low-frequency electric and magnetic fieldsPublication . Makarov, Vladimir I.; Khmelinskii, IgorWe report that the duration of the egg-to-imago development period of the Drosophila melanogaster, and the imago longevity, are both controllable by combinations of external 3-dimensional (3D) low-frequency electric and magnetic fields (LFEMFs). Both these periods may be reduced or increased by applying an appropriate configuration of external 3D LFEMFs. We report that the longevity of D. melanogaster imagoes correlates with the duration of the egg-to-imago development period of the respective eggs. We infer that metabolic processes in both eggs and imago are either accelerated (resulting in reduced time periods) or slowed down (resulting in increased time periods). We propose that external 3D LFEMFs induce electric currents in live systems as well as mechanical vibrations on sub-cell, whole-cell and cell-group levels. These external fields induce media polarization due to ionic motion and orientation of electric dipoles that could moderate the observed effects. We found that the longevity of D. melanogaster imagoes is affected by action of 3D LFEMFs on the respective eggs in the embryonic development period (EDP). We interpret this effect as resulting from changes in the regulation mechanism of metabolic processes in D. melanogaster eggs, inherited by the resulting imagoes. We also tested separate effects of either 3D electric or 3D magnetic fields, which were significantly weaker.
- Macroalgal morphogenesis induced by waterborne compounds and bacteria in coastal seawaterPublication . Grueneberg, Jan; Engelen, Aschwin H.; Costa, Rodrigo; Wichard, ThomasAxenic gametes of the marine green macroalga Ulva mutabilis Foyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseo-bacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal) at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida) were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions) regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation) was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal growth factors in a shallow water body separated from the open ocean by barrier islands might have strong implications to, for example, the wide usage of natural coastal seawater in algal (land based) aquacultures of Ulva.
- Prospecção e defesa da paisagem urbana do Algarve (1965-70): a arquitetura tradicional e a preservação do património urbano na proposta da DGSUPublication . Ribeiro, Vítor; Costa, Miguel Reimão; Aguiar, José; Valverde, IsabelNo contexto da sucessiva redefinição do conceito de património, a arquitetura vernácula tenderá a assumir a sua importância a partir da segunda metade do século passado, alcançando estatuto próprio na Carta sobre o Património Construído Vernáculo de 1999. Em Portugal, adquirem particular relevância os trabalhos desenvolvidos em diferentes âmbitos, desde a antropologia à arquitetura, passando pela agronomia e pela geografia, que culminariam em diferentes sínteses sobre o tema, alargadas a todo o território nacional continental. Essa abordagem só no final dos anos 60 viria a ser ensaiada, à escala da região do Algarve, no pioneiro trabalho desenvolvido pela equipa dirigida pelo Arq.º Cabeça Padrão, no âmbito da Secção de Defesa e Recuperação da Paisagem Urbana da Direcção-Geral dos Serviços de Urbanização (DGSU), sob o título “Prospecção, Preservação e Recuperação de Elementos Urbanísticos e Arquitectónicos Notáveis, em Áreas Urbanas e Marginais Viárias, na Região do Algarve”, constituindo um de três estudos complementares a integrar o Plano Regional do Algarve. Dos 49 volumes projectados a partir de 1965, abrangendo 47 aglomerados urbanos de dimensões muito diversas e maioritariamente localizados na faixa litoral da região, apenas de cerca de metade se conhece hoje o paradeiro. Mas se bem que rapidamente tenham sido remetidos - até muito recentemente -, ao esquecimento dos arquivos, e pese embora o seu carácter datado, constituem um conjunto documental singular de inegável importância, pela metodologia e propostas que encerram, no contexto da evolução histórica dos conceitos e práticas de valorização e conservação patrimonial (em particular no que se refere ao património arquitectónico urbano de carácter vernáculo) e de planeamento e intervenção em áreas urbanas consolidadas. Importância reforçada pelo extenso levantamento fotográfico produzido e onde se fixou um momento histórico charneira documentando o início de profundas transformações - que se acentuariam nas décadas subsequentes -, entre outras razões, por força da emergente importância do turismo. Com a presente comunicação pretende-se resgatar do esquecimento um trabalho verdadeiramente pioneiro (mesmo em termos mundiais) no que se refere à preservação e recuperação da paisagem urbana do Algarve, avaliando a sua metodologia e abordagem particular no âmbito das intervenções em espaço urbano e retomando um processo de análise e caracterização da arquitetura tradicional da região a partir do valioso espólio fotográfico constante neste estudo.
- Coupling tendencies during exploratory behaviours of competing players in rugby union dyadsPublication . Correia, Vanda; Passos, Pedro; Araújo, Duarte; Davids, Keith; Diniz, Ana; Kelso, J. A. ScottThis study investigated interpersonal coordination tendencies in 1vs.1 dyads in rugby union, here expressed by participants' movement velocity towards or away from the sideline as they competed to score or prevent a try. We examined whether coupling tendencies of members of each dyad shaped key performance outcomes (try or successful tackle). Data on movement displacement trajectories of eight male rugby union players (aged 11-12 years) were analysed during performance in 47 trials. To assess coordination tendencies during exploratory behaviours in the dyads, analyses of performance time series data were undertaken using variable time graphs, running correlations and cross-correlations. Results revealed distinct coupling patterns characterised by shifts between synchronous coordination and asynchronous coordination tendencies and uncoordinated actions. Observed behaviours were interpreted as attempts of competing participants to create and perceive possibilities for action while seeking to achieve specific performance goals. Findings also revealed that a variety of patterned relations between participants resulted in different performance outcomes.
- Reflexões sobre o campo do cinema e educaçãoPublication . Pacheco, RaquelNão estamos engatinhando, não estamos no começo, estamos nos arrastando na área. É porque ainda não se encontrou uma maneira adequada, ou mais interessante, de se fazer isso. Apesar do campo já existir há muitos anos, ou melhor, décadas, atualmente continuamos tentando provar que ele é importante. Me parece que existe um vácuo entre quem está fazendo, quem está aprendendo e a relação com o governo e com a escola. Há uma ausência de comunicação. (Índia Martins – Professora de cinema e educação da UFF, 2014) . A afirmação, acima, de Martins dá conta de um problema de base em relação ao campo do cinema e educação no país. Este é o assunto central deste artigo que pretende refletir sobre o cinema e educação enquanto campo baseando-se no trabalho que desenvolvemos ao longo dos últimos anos. Para compreendermos com mais clareza esta temática, primeiro vamos conhecer um pouco da sua história. Em um estudo sobre a relevância do movimento anarquista1 no Brasil e seu envolvimento com o cinema, no início do século XX, em um período que vai dos anos 1901 a 1921, Figueira (2004) faz um relato sobre a introdução e os usos do cinematógrafo pela Igreja, pelo Estado e pela indústria/mercado, na sociedade Brasileira.
- Regenerative memory in time-delayed neuromorphic photonic resonatorsPublication . Romeira, Bruno; Avó, R.; Figueiredo, José; Barland, S.; Javaloyes, JulienWe investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the FitzHugh-Nagumo model with delayed feedback. This proof-of-concept photonic regenerative memory might constitute a building block for a new class of neuron-inspired photonic memories that can handle high bit-rate optical signals.
- Modeling of the lycopene extraction from tomato pulpsPublication . Dolatabadi, Zahra; Rad, Amir Hossien Elhami; Farzaneh, Vahid; Feizabad, Seyed Hashem Akhlaghi; Estiri, Seyed Hossein; Bakhshabadi, HamidThe inputs of this network were the concentration of pectinase and time of incubation, and the outputs were extracted lycopene and the activity of radical scavenging activity. Two different networks were designed for the process under the sonication and without it. For optimal network, networks' transfer functions and different learning algorithms were evaluated and the validity of each one was determined. Consequently, the feedforward neural network with function of logarithmic transfer, Levenberg Marquardt algorithm and 4 neurons in the hidden layer with the correlation coefficient of 0.96 and 0.99 were respectively observed for the treatments under sonication and without it, furthermore, root mean squared error and standard error values were obtained 0.46 and 0.22 respectively for the treatments under sonication and 0.77 and 0.38 without it as respectively optimal networks. The selected networks could determine the chosen responses, individually and in combined effect of both inputs as well (R-2 > 0.98). (C) 2015 Elsevier Ltd. All rights reserved.
- Learning from differences: a strategy for teacher development in respect to student diversityPublication . Messiou, Kyriaki; Ainscow, Mel; Echeita, Gerardo; Goldrick, Sue; Hope, Max; Paes, Isabel; Sandoval, Marta; Simon, Cecilia; Vitorino, TeresaDrawing on evidence gathered as a result of collaborative action research carried out in 8 secondary schools in 3 European countries, this paper proposes an innovative strategy for helping teachers respond positively to learner diversity. The strategy merges the idea of lesson study with an emphasis on listening to the views of students. The research suggests that it is this latter emphasis that makes the difference as far as responding to learner diversity is concerned. It is this that brings a critical edge to the process that has the potential to challenge teachers to go beyond the sharing of existing practices in order to invent new possibilities for engaging students in their lessons. The paper also considers some of the difficulties involved in using this strategy.
- Higher central extensions and cohomologyPublication . Rodelo, Diana; Van der Linden, TimWe establish a Galois-theoretic interpretation of cohomology in semi-abelian categories: cohomology with trivial coefficients classifies central extensions, also in arbitrarily high degrees. This allows us to obtain a duality, in a certain sense, between "internal" homology and "external" cohomology in semiabelian categories. These results depend on a geometric viewpoint of the concept of a higher central extension, as well as the algebraic one in terms of commutators. (C) 2015 Elsevier Inc. All rights reserved.