Browsing by Issue Date, starting with "2016-07"
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- Central role of betaine-homocysteine S-methyltransferase 3 in chondral ossification and evidence for sub-functionalization in neoteleost fishPublication . Rosa, Joana; Tiago, Daniel; Marques, Cátia L.; Vijayakumar, Parameswaran; Fonseca, Luís; Cancela, Leonor; Laizé, VincentBackground: To better understand the complex mechanisms of bone formation it is fundamental that genes central to signaling/regulatory pathways and matrix formation are identified. Cell systems were used to analyze genes differentially expressed during extracellular matrix mineralization and bhmt3, coding for a betaine-homocysteine S-methyltransferase, was shown to be down-regulated in mineralizing gilthead seabream cells.Methods: Levels and sites of bhmt3 expression were determined by qPCR and in situ hybridization throughout seabream development and in adult tissues. Transcriptional regulation of bhmt3 was assessed from the activity of promoter constructs controlling luciferase gene expression. Molecular phylogeny of vertebrate BHMT was determined from maximum likelihood analysis of available sequences.Results: bhmt3 transcript is abundant in calcified tissues and localized in cartilaginous structures undergoing endo/perichondral ossification. Promoter activity is regulated by transcription factors involved in bone and cartilage development, further demonstrating the central role of Bhmt3 in chondrogenesis and/or osteogenesis. Molecular phylogeny revealed the explosive diversity of bhmt genes in neoteleost fish, while tissue distribution of bhmt genes in seabream suggested that neoteleostean Bhmt may have undergone several steps of sub-functionalization.Conclusions: Data on bhmt3 gene expression and promoter activity evidences a novel function for betaine-homocysteine S-methyltransferase in bone and cartilage development, while phylogenetic analysis provides new insights into the evolution of vertebrate BHMTs and suggests that multiple gene duplication events occurred in neoteleost fish lineage.General significance: High and specific expression of Bhmt3 in gilthead seabream calcified tissues suggests that bone-specific betaine-homocysteine S-methyltransferases could represent a suitable marker of chondral ossification.
- Judge me, judge me not: The role of eye size and observer gender on acquaintance rapePublication . Ferrão, Maria Clara; Gonçalves, Gabriela Maria Ramos; Giger, Jean-Christophe; Parreira, TiagoThe purpose of this study was to examine the effect of eye size and observer gender on perceived initial attraction, honesty, and attributions of responsibility for rape. A 3 (eye size: small vs. normal vs. large) x 2 (observer gender: female vs. male) experimental design was tested. Ninety participants (45 women and 45 men) observed one of three randomly assigned female faces (with eye size manipulation), and rated initial attraction and honesty. They were then asked to read an acquaintance rape scenario with a traditional woman, rating the victim and perpetrator responsibility. Eye size was shown to affect all the study variables: the female face with large eyes was seen as more attractive and honest, was held less responsible for her own victimization, and the offender was held more responsible. Gender was proven to affect perceived initial attraction and victim responsibility. Theoretical and practical implications were discussed.
- MERIS phytoplankton time series products from the SW Iberian Peninsula (Sagres) using seasonal-trend decomposition based on loessPublication . Cristina, Sónia; Cordeiro, Clara; Lavender, Samantha; Goela, Priscila; Icely, John; Newton, AliceThe European Space Agency has acquired 10 years of data on the temporal and spatial distribution of phytoplankton biomass from the MEdium Resolution Imaging Spectrometer (MERIS) sensor for ocean color. The phytoplankton biomass was estimated with the MERIS product Algal Pigment Index 1 (API 1). Seasonal-Trend decomposition of time series based on Loess (STL) identified the temporal variability of the dynamical features in the MERIS products for water leaving reflectance ((w)()) and API 1. The advantages of STL is that it can identify seasonal components changing over time, it is responsive to nonlinear trends, and it is robust in the presence of outliers. One of the novelties in this study is the development and the implementation of an automatic procedure, stl.fit(), that searches the best data modeling by varying the values of the smoothing parameters, and by selecting the model with the lowest error measure. This procedure was applied to 10 years of monthly time series from Sagres in the Southwestern Iberian Peninsula at three Stations, 2, 10 and 18 km from the shore. Decomposing the MERIS products into seasonal, trend and irregular components with stl.fit(), the (w)() indicated dominance of the seasonal and irregular components while API 1 was mainly dominated by the seasonal component, with an increasing effect from inshore to offshore. A comparison of the seasonal components between the (w)() and the API 1 product, showed that the variations decrease along this time period due to the changes in phytoplankton functional types. Furthermore, inter-annual seasonal variation for API 1 showed the influence of upwelling events and in which month of the year these occur at each of the three Sagres stations. The stl.fit() is a good tool for any remote sensing study of time series, particularly those addressing inter-annual variations. This procedure will be made available in R software.
- Psychometric properties of a portuguese version of the SOCRATES 8D: a study with a sample of heroin addicts in treatmentPublication . Janeiro, Luís; Faísca, Luís; Lopez Miguel, Maria JoséIn the present study, we adapted the Stage of Change Readiness and Treatment Eagerness Scale (SOCRATES, version 8D) to the European Portuguese and we examined its factor structure and psychometric properties. The scale was applied to a sample of 100 adults, mostly heroin addicts, in outpatient or inpatient treatment. A Principal Component Analysis applied to the data revealed three dimensions - Problem Recognition, Taking Steps and Ambivalence -, corresponding almost exactly to the factor structure originally proposed by Miller and Tonigan (1996). The reliability indices for SOCRATES three subscales (internal consistency and temporal stability) were adequate. External validity study showed that the subscales differentiated treatment contexts and were associated to the participants' evaluation regarding the treatment expectations and the technical team. Thus, the Portuguese version of SOCRATES 8D seems to possess the proper psychometric properties to evaluate drug addicts' treatment motivation.
- On the model updating operators in univariate estimation of distribution algorithmsPublication . Bronevich, Andrey G.; Oliveira, José Valente deThe role of the selection operation-that stochastically discriminate between individuals based on their merit-on the updating of the probability model in univariate estimation of distribution algorithms is investigated. Necessary conditions for an operator to model selection in such a way that it can be used directly for updating the probability model are postulated. A family of such operators that generalize current model updating mechanisms is proposed. A thorough theoretical analysis of these operators is presented, including a study on operator equivalence. A comprehensive set of examples is provided aiming at illustrating key concepts, main results, and their relevance.
- Diversity, structure and convergent evolution of the global sponge microbiomePublication . Thomas, Torsten; Moitinho-Silva, Lucas; Lurgi, Miguel; Bjoerk, Johannes R.; Easson, Cole; Astudillo-Garcia, Carmen; Olson, Julie B.; Erwin, Patrick M.; Lopez-Legentil, Susanna; Luter, Heidi; Chaves-Fonnegra, Andia; Costa, Rodrigo; Schupp, Peter J.; Steindler, Laura; Erpenbeck, Dirk; Gilbert, Jack; Knight, Rob; Ackermann, Gail; Lopez, Jose Victor; Taylor, Michael W.; Thacker, Robert W.; Montoya, Jose M.; Hentschel, Ute; Webster, Nicole S.Sponges (phylum Porifera) are early-diverging metazoa renowned for establishing complex microbial symbioses. Here we present a global Porifera microbiome survey, set out to establish the ecological and evolutionary drivers of these host-microbe interactions. We show that sponges are a reservoir of exceptional microbial diversity and major contributors to the total microbial diversity of the world's oceans. Little commonality in species composition or structure is evident across the phylum, although symbiont communities are characterized by specialists and generalists rather than opportunists. Core sponge microbiomes are stable and characterized by generalist symbionts exhibiting amensal and/or commensal interactions. Symbionts that are phylogenetically unique to sponges do not disproportionally contribute to the core microbiome, and host phylogeny impacts complexity rather than composition of the symbiont community. Our findings support a model of independent assembly and evolution in symbiont communities across the entire host phylum, with convergent forces resulting in analogous community organization and interactions.
- Assessment and comparison of the properties of biodiesel synthesized from three different types of wet microalgal biomassPublication . Gangadhar, Katkam N.; Pereira, Hugo; Diogo, Herminio P.; Borges dos Santos, R. M.; Devi, B. L. A. Prabhavathi; Prasad, R. B. N.; Custódio, Luísa; Xavier Malcata, F.; Varela, João; Barreira, LuísaIn recent years, microalgae-based carbon-neutral biofuels (i.e., biodiesel) have gained considerable interest due to high growth rate and higher lipid productivity of microalgae during the whole year, delivering continuous biomass production as compared to vegetable-based feedstocks. Therefore, biodiesel was synthesized from three different microalgal species, namely Tetraselmis sp. (Chlorophyta) and Nannochloropsis oculata and Phaeodactylum tricornutum (Heterokontophyta), and the fuel properties of the biodiesel were analytically determined, unlike most studies which rely on estimates based on the lipid profile of the microalgae. These include density, kinematic viscosity, total and free glycerol, and high heating value (HHV), while cetane number (CN) and cold filter plugging point (CFPP) were estimated based on the fatty acid methyl ester profile of the biodiesel samples instead of the lipid profile of the microalgae. Most biodiesel properties abide by the ASTM D6751 and the EN 14214 specifications, although none of the biodiesel samples met the minimum CN or the maximum content of polyunsaturated fatty acids with a parts per thousand yen4 double bonds as required by the EN 14214 reference value. On the other hand, bomb calorimetric experiments revealed that the heat of combustion of all samples was on the upper limit expected for biodiesel fuels, actually being close to that of petrodiesel. Post-production processing may overcome the aforementioned limitations, enabling the production of biodiesel with high HHV obtained from lipids present in these microalgae.
- Mechanisms of vertebrate embryo segmentation: Common themes in trunk and limb developmentPublication . Sheeba, C.J.; Andrade, Raquel P.; Palmeirim, IsabelVarious ultradian rhythms ensure proper temporal regulations during embryo development. The embryo molecular clock, which was first identified in the presomitic mesoderm (PSM) underlying periodic somite formation, is one among them. Somites are the earliest manifestation of the segmented vertebrate body and they are formed with strict temporal precision. The tetrapod limb is also a segmented structure and the formation of limb bone elements have also been associated with a molecular clock, operating in the distal limb mesenchyme. In both the PSM and the distal limb mesenchyme, the molecular clock (MC) is influenced by FGF, SHH and RA, which are also the key regulators of the development of these tissues. While somitogenesis has been continuously scrutinized to understand the mechanisms of the MC, the limb bud has served as an outstanding paradigm to study how a cohort of undifferentiated cells is organized into functional 3D structures. The fact that both the trunk and limb development are shaped by the MC and by common signaling molecules has prompted the exciting possibility of establishing parallelisms between somitogenesis and limb development. Systematically correlating various parameters during trunk and limb development will help us to appreciate the common principles underlying segmented structure formation and allow the rise of new questions in order to fill the gaps in our present understanding. In this review we have established the parallelisms between somitogenesis and limb development at the level of gene expression patterns and their regulation. Finally, we have also discussed the most evident new avenues this exercise could open to the scientific community. (C) 2016 Elsevier Ltd. All rights reserved.
- Conspicuous consumption of the elite: Social and self-congruity in tourism choicesPublication . Correia, Antónia; Kozak, Metin; Reis Figueiredo, HelenaThis paper relies on social and economic psychology to explore how the travel choices of Portuguese citizens, with different status levels in their daily lives, perceive and adopt different conspicuous travel patterns because of public exposure. To account for the moderated role of public exposure on conspicuous travel patterns, 36 Portuguese citizens were interviewed. Q-methods were applied to explore the varying senses of conspicuous travel choices among citizens with different levels of public exposure, both individually and relative to each other. Complementary qualitative methods were applied, in order to explore how the interviewees construct tourism conspicuous meanings that match their social or self-representations. The results suggest that social contexts moderate the ways in which individuals perceive and experience conspicuous travel. Further, the results show that public groups with higher exposure tend to prefer subtle signals of conspicuousness, in order to differentiate themselves from the mainstream.
- Climate changes in south western Iberia and Mediterranean Outflow variations during two contrasting cycles of the last 1 Myrs: MIS 31-MIS 30 and MIS 12-MIS 11Publication . Goni, Maria F. Sanchez; Llave, E.; Oliveira, D.; Naughton, F.; Desprat, S.; Ducassou, E.; Hodell, D. A.; Hernandez-Molina, Francisco J.Grain size analysis and physical properties of Sites U1388, U1389 and TJ1390 collected in the Contourite Depositional System of the Gulf of Cadiz during the Integrated Ocean Drilling Program (IODP) Expedition 339 "Mediterranean Outflow" reveal relative changes in bottom current strength, a tracer of the dynamics of the Mediterranean Outflow Water (MOW), before and after the Middle Pleistocene Transition (MPT). The comparison of MOW behavior with climate changes identified by the pollen analysis and 8180 benthic foraminifera measurements of Site U1385, the Shackleton Site, collected in the south western Iberian margin shows that the interval MIS 31-MIS 30,similar to 1.1-1.05 million years ago (Ma), before the MPT, was marked by wetter climate and weaker bottom current than the interval MIS 12-MIS 11 (0.47-0.39 Ma), after the MPT. Similarly, the increase in fine particles from these glacials to interglacials and in coarse fraction from interglacials to glacials was coeval with forest and semi-desert expansions, respectively, indicating the lowering/enhancement of MOW strength during periods of regional increase/decrease of moisture. While these findings may not necessarily apply to all glacial/interglacial cycles, they nonetheless serve as excellent supporting examples of the hypothesis that aridification can serve as a good tracer for MOW intensity. The strongest regional aridity during MIS 12 coincides with a remarkable increase of coarse grain size deposition and distribution that we interpret as a maximum in MOW strength. This MOW intensification may have pre-conditioned the North Atlantic by increasing salinity, thereby triggering the strong resumption of the Meridional Overturning Circulation that could contribute to the great warmth that characterizes the MIS 11c super-interglacial. (C) 2015 Elsevier B.V. All rights reserved.