Browsing by Issue Date, starting with "2018-05"
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- Testing lorentz and CPT invariance with ultracold neutronsPublication . Martin-Ruiz, A.; Escobar, CarlosIn this paper we investigate, within the standard model extension framework, the influence of Lorentz- and CPT-violating terms on gravitational quantum states of ultracold neutrons. Using a semiclassical wave packet, we derive the effective nonrelativistic Hamiltonian which describes the neutrons vertical motion by averaging the contributions from the perpendicular coordinates to the free falling axis. We compute the physical implications of the Lorentz- and CPT-violating terms on the spectra. The comparison of our results with those obtained in the GRANIT experiment leads to an upper bound for the symmetries-violation c(mu nu)(n) coefficients. We find that ultracold neutrons are sensitive to the a(i)(n) and e(i)(n) coefficients, which thus far are unbounded by experiments in the neutron sector. We propose two additional problems involving ultracold neutrons which could be relevant for improving our current bounds; namely, gravity-resonance spectroscopy and neutron whispering gallery wave.
- Effects of different slipping methods on the mortality of sardine, Sardina pilchardus, after purse-seine capture off the Portuguese Southern coast (Algarve)Publication . Marçalo, Ana; Guerreiro, Pedro; Bentes, Luis; Rangel, Mafalda; Monteiro, Pedro; Oliveira, Frederico; Afonso, Carlos; Pousao-Ferreira, Pedro; Benoit, Hugues P.; Breen, Mike; Erzini, Karim; Gonçalves, Jorge Manuel SantosThe effects of two different slipping methods on the survival, physical and physiological response of sardines, Sardina pilchardus, captured in a purse-seine fishery were investigated in southern Portugal. Sardines were collected and transferred into holding tanks onboard a commercial fishing vessel after being captured, crowded and deliberately released using two slipping procedures: standard and modified. The standard slipping procedure aggregated fish at high densities and made them "roll over" the floatline, while the modified procedure aggregated the fish at moderate densities and enabled them to escape through an opening created by adding weights to the floatline. Both slipping methods were compared with minimally harmed non-slipped sardines (sardines collected from the loose pocket of the purse seine). Survival rates were monitored in captivity over 28 days using three replicates for each treatment. The estimated survival of sardines was 43.6% for the non-slipped fish, 44.7% for the modified slipping and 11.7% for the standard slipping treatments. Scale loss indicated the level of physical impact experienced, with dead fish from the non-slipped and modified slipping technique showing significantly lower scale loss than those fish from the standard slipping treatment within the same period. Of the physiological indicators of stress measured, cortisol, glucose, lactate and osmolality attained peak values during slipping and up to the first hours after introduction to captivity. This work indicates that although delayed mortality after release may be substantial, appropriately modified slipping techniques significantly enhance survival of slipped sardines.
- Sustainable planning of cross-border cooperation: a strategy for alliances in border citiesPublication . Kurowska-Pysz, Joanna; Castanho, Rui Alexandre; Loures, LuisIn recent years, cooperation among nations has become a critical issue towards sustainable development of neighbor cities in border areas. In this regard, sustainable common planning approaches and policies are an increasing reality, particularly in European territories. Considering the significant amount of cross-border cooperation (CBC) projects and strategies within Europe, it is crucial to promote research approaches that are able to identify the most positive approaches towards the establishment of alliances in border territories, serving as pivotal methodologies for achieving success. Contextually, the present study considered direct and indirect research methods and tools, literature reviews, data collection, computer-assisted telephone interviewing (CATI) and computer-assisted web interview (CAWI), all applied over two European border cities: Cieszyn (Poland) and Cesky Tesin (Czech Republic). These methods enabled the assembly of perspectives of local authorities, public and private institutions, non-governmental organizations, and entrepreneurs from the cities under study. Through the analysis of the collected data, five conditions have been identified for the success of strategic alliances in CBC projects: (i) well defining the alliance goals; (ii) ensuring participation in the alliance of various groups of stakeholders; (iii) involvement of both partners with extensive experience in CBC; (iv) ensuring the coherence of the key objective; and (v) guaranteeing the alliance benefits both sides. These conditions might effectively contribute to achieve more successful outputs in CBC projects, highlighting the relevance of previously developed strategies on the definition of future approaches.
- High CO2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicumPublication . SORDO, LAURA; Santos, Rui; Barrote, Isabel; Silva, JoãoMaerl/rhodolith beds are protected habitats that may be affected by ocean acidification (OA), but it is still unclear how the availability of CO2 will affect the metabolism of these organisms. Some of the inconsistencies found among OA experimental studies may be related to experimental exposure time and synergetic effects with other stressors. Here, we investigated the long-term (up to 20months) effects of OA on the production and calcification of the most common maerl species of southern Portugal, Phymatolithon lusitanicum. Both the photosynthetic and calcification rates increased with CO2 after the first 11months of the experiment, whereas respiration slightly decreased with CO2. After 20months, the pattern was reversed. Acidified algae showed lower photosynthetic and calcification rates, as well as lower accumulated growth than control algae, suggesting that a metabolic threshold was exceeded. Our results indicate that long-term exposure to high CO2 will decrease the resilience of Phymatolithon lusitanicum. Our results also show that shallow communities of these rhodoliths may be particularly at risk, while deeper rhodolith beds may become ocean acidification refuges for this biological community.
- “Heinrich events” (& sediments): A history of terminology and recommendations for future usagePublication . Andrews, John T.; Voelker, Antje
- Modality effects in implicit artificial grammar learning: An EEG studyPublication . Silva, Susana; Folia, Vasiliki; Inácio, Filomena; Castro, Sao Luis; Petersson, Karl MagnusRecently, it has been proposed that sequence learning engages a combination of modality-specific operating networks and modality-independent computational principles. In the present study, we compared the behavioural and EEG outcomes of implicit artificial grammar learning in the visual vs. auditory modality. We controlled for the influence of surface characteristics of sequences (Associative Chunk Strength), thus focusing on the strictly structural aspects of sequence learning, and we adapted the paradigms to compensate for known frailties of the visual modality compared to audition (temporal presentation, fast presentation rate). The behavioural outcomes were similar across modalities. Favouring the idea of modality-specificity, ERPs in response to grammar violations differed in topography and latency (earlier and more anterior component in the visual modality), and ERPs in response to surface features emerged only in the auditory modality. In favour of modality-independence, we observed three common functional properties in the late ERPs of the two grammars: both were free of interactions between structural and surface influences, both were more extended in a grammaticality classification test than in a preference classification test, and both correlated positively and strongly with theta event-related-synchronization during baseline testing. Our findings support the idea of modality-specificity combined with modality-independence, and suggest that memory for visual vs. auditory sequences may largely contribute to cross-modal differences. (C) 2018 Elsevier B.V. All rights reserved.
- Molecular effect of an OPTN common variant associated to Paget's disease of bonePublication . Silva, Iris; Conceição, Natércia; Gagnon, Edith; Brown, Jacques P.; Cancela, M. Leonor; Michou, LaetitiaPaget's disease of bone (PDB) is a chronic bone disorder and although genetic factors appear to play an important role in its pathogenesis, to date PDB causing mutations were identified only in the Sequestosome 1 (SQSTM1) gene at the PDB3 locus. PDB6 locus, also previously linked to PDB, contains several candidate genes for metabolic bone diseases. We focused our analysis in the most significantly associated variant with PDB, within the Optineurin (OPTN) gene, i.e. the common variant rs1561570. Although it was previously shown to be strongly associated with PDB in several populations, its contribution to PDB pathogenesis remains unclear. In this study we have shown that rs1561570 may contribute to PDB since its Tallele results in the loss of a methylation site in patients' DNA, leading to higher levels of OPTN gene expression and a corresponding increase in protein levels in patients' osteoclasts. This increase in OPTN expression leads to higher levels of NF-KB translocation into the nucleus and increasing expression of its target genes, which may contribute to the overactivity of osteoclasts observed in PDB. We also reported a tendency for a more severe clinical phenotype in the presence of a haplotype containing the rs1561570 T allele, which appear to be re-enforced with the presence of the SQSTM1/P392L mutation. In conclusion, our work provides novel insight towards understanding the functional effects of this variant, located in OPTN intron 7, and its implication in the contribution to PDB pathogenesis.
- Utilização do conceito F-Tool como ferramenta de avaliaçãoPublication . Conceição, Ana C.O conceito F-Tool tem como objetivo estimular o interesse e participação dos alunos na apropriação e consolidação de conceitos nas áreas do Pré-Cálculo e do Cálculo Diferencial. A sua utilização adequada conduz a um contexto de ensino-aprendizagem onde discentes e docentes são igualmente convidados a contribuir. Neste artigo pretende- se exemplificar como a utilização do software educacional F-Tool pode ser utilizado como ferramenta de avaliação.
- Red algal extracts from Plocamium lyngbyanum and Ceramium secundatum stimulate osteogenic activities in vitro and bone growth in zebrafish larvaePublication . Carson, Matthew A.; Nelson, John; Cancela, M. Leonor; Laizé, Vincent; Gavaia, Paulo J.; Rae, Margaret; Heesch, Svenja; Verzin, Eugene; Maggs, Christine; Gilmore, Brendan F.; Clarke, Susan A.Through the current trend for bioprospecting, marine organisms-particularly algae-are becoming increasingly known for their osteogenic potential. Such organisms may provide novel treatment options for osteoporosis and other musculoskeletal conditions, helping to address their large healthcare burden and the limitations of current therapies. In this study, extracts from two red algae-Plocamium lyngbyanum and Ceramium secundatum-were tested in vitro and in vivo for their osteogenic potential. In vitro, the growth of human bone marrow stromal cells (hBMSCs) was significantly greater in the presence of the extracts, particularly with P. lyngbyanum treatment. Osteogenic differentiation was promoted more by C. secundatum (70 mu g/ml), though P. lyngbyanum had greater in vitro mineralisation potential. Both species caused a marked and dose-dependent increase in the opercular bone area of zebrafish larvae. Our findings therefore indicate the presence of bioactive components in P. lyngbyanum and C. secundatum extracts, which can promote both in vitro and in vivo osteogenic activity.
- Diversity of Phytophthora species in Valdivian rainforests and association with severe dieback symptomsPublication . Jung, Thomas; Durán, Alvaro; Stowasser, Eugenio Sanfuentes von; Schena, Leonardo; Mosca, Saveria; Fajardo, Sebastian; González, Mariela; Navarro Ortega, Angella D.; Bakonyi, Jozsef; Seress, Diana; Michal Tomšovský; Cravador, Alfredo; Maia, Cristiana; Marilia Horta Jung; Horta Jung, Marília; Jung, Thomas; Cravador, AlfredoThe Valdivian rainforest, one of the global hotspots of biodiversity, is a temperate rainforest originating as a Tertiary relic from the supercontinent Gondwana. In November 2014, a survey of Phytophthora diversity was performed in 13 natural forest stands and 20 forest streams and rivers in two protected areas near Valdivia and in a temperate montane forest in the Concepción area. One planted stand each of the introduced tree species Castanea sativa and Fagus sylvatica were also included. Using baiting assays, eight described species and four previously unknown taxa of Phytophthora were isolated from 86% of the 50 rhizosphere soil samples from seven of the eight tree species sampled in 12 forest stands, and from 20 streams: P. chlamydospora, P. cinnamomi, P. kernoviae, P. lacustris, P. plurivora, P. pseudosyringae, P. ×cambivora, P. ×stagnum, P. valdiviana nom. prov. from Clade 2b, P. madida nom. prov. from Clade 8a, and P. chilensis nom. prov. and P. pseudokernoviae nom. prov. The latter two species are the closest relatives of P. kernoviae from Clade 10. Phytophthora pseudokernoviae nom. prov. was also isolated from necrotic leaves of Drimys winteri. From the Valdivia river, a swarm of three Clade 6 hybrids was recovered. Each hybrid isolate resulted from multiple reticulation events with P. thermophila as maternal and both P. amnicola and P. chlamydospora as paternal parents. In addition, three previously unknown and recently described Nothophytophthora species, N. caduca, N. chlamydospora and N. valdiviana, were isolated from several forest streams. Phytophthora cinnamomi, the most common and widespread species in soils of native forests, was associated with severe dieback of Valdivian rainforest trees, in particular D. winteri, Luma apiculata, Nothofagus dombeyi and the endangered Saxegothaea conspicua. A first pathogenicity test demonstrated high aggressiveness of P. cinnamomi to several native tree species, including N. dombeyi, Blepharocalyx cruckshanksii and Gevuina avellana.