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- Concentrations of available heavy metals in mediterranean agricultural soils and their relation with some soil selected properties: a case study in typical mediterranean soilsPublication . Nunes, Jose Rato; Ramos-Miras, Jose; Lopez-Pineiro, Antonio; Loures, Luis; Gil, Carlos; Coelho, Jose; Loures, AnaThe characterization of the content of trace metals in soils is an instrument in many programs of environmental protection, including the establishment of regional-level standards to detect sites affected by contamination. The objectives of the present study were to study the available levels of Cd, Cr, Cu, Ni, Pb, and Zn in surface horizons of agricultural soils in a typical European Mediterranean region, to establish the geochemical baseline concentration (GBC), background level (BL), and reference value (RV) of each of these available metals, and to investigate their possible correlations with soil properties. To establish the GBC and RV values, we used the " standard threshold method". Topsoil samples (0-20 cm) were collected from 630 sites, and extracted with Diethylene Triamine Pentaacetic Acid (DTPA) to determine their available heavy metal concentrations. The GBC values established were: 0.04 to 0.90 mg kg(-1), 0.70 to 2.50 mg kg(-1), 0.10 to 6.30 mg kg(-1), 0.30 to 7.90 mg kg(-1), 0.29 to 4.50 mg kg(-1), and 0.18 to 2.50 mg kg(-1) for Cd, Cr, Cu, Ni, Pb, and Zn, respectively. Soil properties were found to be correlated with the available heavy metal content, suggesting that the enhanced mobility of heavy metals are related to anthropic activities.
- Expression and Function of Ccbe1 in the Chick Early Cardiogenic Regions Are Required for Correct Heart DevelopmentPublication . Furtado, João; Bento, Margaret; Correia, Elizabeth; Inacio, Jose Manuel; Belo, José A.During the course of a differential screen to identify transcripts specific for chick heart/hemangioblast precursor cells, we have identified Ccbe1 (Collagen and calcium-binding EGF-like domain 1). While the importance of Ccbe1 for the development of the lymphatic system is now well demonstrated, its role in cardiac formation remained unknown. Here we show by whole-mount in situ hybridization analysis that cCcbe1 mRNA is initially detected in early cardiac progenitors of the two bilateral cardiogenic fields (HH4), and at later stages on the second heart field (HH9-18). Furthermore, cCcbe1 is expressed in multipotent and highly proliferative cardiac progenitors. We characterized the role of cCcbe1 during early cardiogenesis by performing functional studies. Upon morpholino-induced cCcbe1 knockdown, the chick embryos displayed heart malformations, which include aberrant fusion of the heart fields, leading to incomplete terminal differentiation of the cardiomyocytes. cCcbe1 overexpression also resulted in severe heart defects, including cardia bifida. Altogether, our data demonstrate that although cardiac progenitors cells are specified in cCcbe1 morphants, the migration and proliferation of cardiac precursors cells are impaired, suggesting that cCcbe1 is a key gene during early heart development.
- A alimentação do diabético: do que se diz....ao que se sabePublication . Braz, NidiaA alimentação do diabético: do que se diz....ao que se sabe
- Investigations into the Mechanism of Solvolysis of 3-aryloxybenzisothiazolesPublication . Ismael, Amin; Gago, David J. P.; Cabral, Lília; Fausto, Rui; Cristiano, Maria De LurdesThe solvolysis of selected 3-aryloxybenzisothiazoles (6a-c; Figure 1) in alcohols has been theoretically investigated. The geometries of ethers 6a-c were fully optimized at the DFT(O3LYP) level, with the 6-31++G(d,p) and 6-311++G(3df,3pd) basis sets. Calculations including solvation effects were performed with the 6-31++G(d,p) basis set. Overall, theoretical values for bond lengths and angles around the central ether linkage in ethers 6a-c are very close, for the isolated molecule and in methanol, and are also very close to those obtained by X-ray crystallography, revealing that the nature of the substituent on the aryl system has a negligible effect on geometric parameters around the ether linkage. The same applies to charge distributions, predicted using the NPA approach. However, measured rate constants for the solvolysis of the same compounds in alcohols show that the rate is affected by the electron-withdrawing/-donating characteristics of the substituent on the aryl ring and by the polarity of solvent. Two general pathways were considered for the solvolysis of ethers 6: associative (addition-elimination) or dissociative (fragmentation-recombination) mechanisms. Molecular orbital calculations by means of polarized continuum model (PCM) reaction field predicted that solvolysis of ethers 6 prefers an addition-elimination mechanism. Calculations show also that a dissociative mechanism for the solvolysis of ethers 6a-c is energetically much more demanding than its addition-elimination counterpart and is therefore a highly improbable pathway for the solvolysis. In addition, it was found that the putative cation intermediate formed during a dissociative process should easily convert into its 2-cyanobenzenesulfone cation isomer, via cleavage of the S-N bond.
- Survival estimates of bycatch individuals discarded from bivalve dredgesPublication . Miguel de Sousa Leitão, Francisco; Range, Pedro; Gaspar, MiguelThe fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata.
- Fluency profile: comparison between Brazilian and European Portuguese speakersPublication . Castro, Blenda Stephanie Alves e; Martins-Reis, Vanessa de Oliveira; Baptista, Ana Catarina; Celeste, Letícia CorreaThe purpose of the study was to compare the speech fluency of Brazilian Portuguese speakers with that of European Portuguese speakers. The study participants were 76 individuals of any ethnicity or skin color aged 18–29 years. Of the participants, 38 lived in Brazil and 38 in Portugal. Speech samples from all participants were obtained and analyzed according to the variables of typology and frequency of speech disruptions and speech rate. Descriptive and inferential statistical analyses were performed to assess the association between the fluency profile and linguistic variant variables. We found that the speech rate of European Portuguese speakers was higher than the speech rate of Brazilian Portuguese speakers in words per minute (p=0.004). The qualitative distribution of the typology of common dysfluencies (p<0.001) also discriminated between the linguistic variants. While a speech fluency profile of European Portuguese speakers is not available, speech therapists in Portugal can use the same speech fluency assessment as has been used in Brazil to establish a diagnosis of stuttering, especially in regard to typical and stuttering dysfluencies, with care taken when evaluating the speech rate.
- Coastline changes and sedimentation related with the opening of an artificial channel: the Valo Grande Delta, SE BrazilPublication . de Mahiques, Michel M.; Figueira, Rubens C. L.; Alves, Daniel P. V.; Italiani, Diana M.; Martins, Cristina C.; Dias, Joao M. A.The role played by human activity in coastline changes indicates a general tendency of retreating coasts, especially deltaic environments, as a result of the recent trend of sea level rise as well as the blockage of the transfer of sediments towards the coast, especially due to the construction of dams. This is particularly important in deltaic environments which have been suffering a dramatic loss of area in the last decades. In contrast, in this paper, we report the origin and evolution of an anthropogenic delta, the Valo Grande delta, on the south-eastern Brazilian coast, whose origin is related to the opening of an artificial channel and the diversion of the main flow of the Ribeira de Iguape River. The methodology included the analysis of coastline changes, bathy metry and coring, which were used to determine the sedimentation rates and grain-size changes over time. The results allowed us to recognize the different facies of the anthropogenic delta and establish its lateral and vertical depositional trends. Despite not being very frequent, anthropogenic deltas represent a favorable environment for the record of natural and anthropogenic changes in historical times and, thus, deserve more attention from researchers of different subjects.
- Algebraic Bethe ansatz for the XXZ Heisenberg spin chain with triangular boundaries and the corresponding Gaudin modelPublication . Antonio, N. Cirilo; Manojlović, Nenad; Salom, I.We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model. (C) 2014 The Authors. Published by Elsevier B.V.
- A deriva na análise do espaço urbano, na perspetiva da média-arte locativaPublication . Carvalho, Isabel Cristina; Bidarra, José; Figueiredo, MauroEste artigo reflete sobre a deriva urbana, em contexto pedagógico, realizada na Vila de Caminha, como prática artista e enquanto exercício de experimentação, leitura e análise daquele espaço. Através de tecnologia móvel, nomeadamente smartphones e tablets, aborda-se a média-arte locativa como instigadora da experimentação de espaços urbanos. Explora-se a deriva como exercício de apreensão urbana e processo de procura e levantamento de narrativas locativas. Com base numa investigação teórica e na análise de resultados empíricos obtidos com tecnologias de realidade aumentada atualmente existentes, reflete-se ainda acerca do papel da média-arte locativa na vivência de espaços urbanos e no seu contributo na preservação da memória e identidades locais, pela descoberta e partilha de narrativas georreferenciadas, contextualizando-as e imbuindo-as no próprio espaço físico.
- Using CHEMTAX to evaluate seasonal and interannual dynamics of the phytoplankton community off the South-west coast of PortugalPublication . Goela, Priscila; Danchenko, S.; Icely, John; Lubian, L. M.; Cristina, S.; Newton, A.CHEMTAX was used to assess the relative contribution of the main phytoplankton classes to the total concentration of Chlorophyll a (Chl a) from the waters off SW coast of Portugal. Sampling campaigns were carried out during all seasons from 2008 to 2012, at three stations located 2, 10 and 18 km from the coast. Samples were taken from the surface, mid-Secchi and Secchi depth, for the determination of Chl a and other phytoplanktonic pigments by HPLC. Supporting data were also obtained including dissolved inorganic nutrients, salinity, transparency, temperature and upwelling indices. The CHEMTAX results were also related to microscopy counts and also spectral analysis of absorption of other samples from the same sampling campaigns. The pigment results showed that diatoms dominated from early spring to summer, coinciding with upwelling conditions, while cryptophytes, prymnesiophytes and prasinophytes dominated in autumn and winter, coinciding with seasonal stratification. Although the contribution of cyanobacteria to total Chl a was generally low, there were occasional sampling campaigns where it was exceptionally high, but these appeared not to be related to upwelling. Dinoflagellates and chrysophytes were minority groups although the pigment marker peridinin that was used to distinguish dinoflagellates was not adequate for distinguishing all the members of this group. CHEMTAX was particularly useful for discriminating between the smaller (0-20 mu m) classes of the microplankton that could not be easily identified by microscopy. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND
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