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- Understanding the role of destination imagery in mountain destination choice. Evidence from an exploratory researchPublication . Araújo, Arthur; Cardoso, Lucília; Araújo, Noelia; Dias, FranciscoThe present study explores the imagery of mountain tourism destinations. The research is based on customer-based brand equity and destination choice models, and addresses destination imagery through the concepts favourite destination (FD) and autobiographical memory. Through an online, multilingual survey, 711 responses, consisting of words, associated by a self-selected sample of European mountain tourists to their favourite mountain destinations, were collected. Such data was subjected to a deductive content analysis, and the results suggest that the imagery of favourite mountain destinations consists mostly of functional elements. Findings reinforce previous theories regarding the concept of favourite destinations, destination imagery (DY) processing, and destination choice. Future studies should apply such analysis to other tourism products, as well as to different or more representative samples, to verify whether imagery structures differ. © 2019, Varna University of Management. All rights reserved.
- Hydrogen peroxide, iodine solution and methylene solution highly enhance the hatching rate of freshwater ornamental fish speciesPublication . Chambel, João; Costa, Ricardo; Gomes, Mónica; Mendes, Susana; Baptista, Teresa; Pedrosa, RuiThe aim of this study was to evaluate the effect of hydrogen peroxide, iodine solution (PVP) and methylene blue on eggs disinfection of three ornamental fish species, Danio rerio, Pterophyllum scalare and Gymnocorymbus ternetzi. The main idea was to create conditions to enhance the hatching rates. Eggs of each species were exposed to different concentrations of hydrogen peroxide (5, 10, 15 and 25 mg/L), PVP (0.25, 0.5, 0.75 and 1 mg/L) and methylene blue (0.5 1, 2 and 3 mg/L). The optimal doses ranged between species and chemicals: for G. ternetzi, the concentrations that high enhanced the hatching rate were 1 mg/L for the PVP treatment, 25 mg/L for the hydrogen peroxide treatment and 3 mg/L for methylene blue treatment; for P. scalare, the best results were achieved with 25 mg/L for hydrogen peroxide treatment and 3 mg/L for methylene blue treatment. By contrast, for all the different chemical did not increased the D. rerio hatching rate. Results showed that hydrogen peroxide and methylene blue are the most versatile, effective and safe to use in these species. On the other hand, PVP can be used but with many precautions due to very low safety margin. Results clearly show that the optimal concentration of chemicals for eggs disinfection is fish species dependent and it is completely wrong to extrapolate concentrations between different chemicals and fish species. Our study suggests that P. scalare can be used as a model in study of effectiveness of new chemicals with potential to disinfect water and increase hatching rates.
- Metabolic and histopathological alterations in the marine bivalve Mytilus galloprovincialis induced by chronic exposure to acrylamidePublication . Larguinho, Miguel; Cordeiro, Ana; Diniz, Mário S.; Costa, Pedro M.; Baptista, Pedro V.Although the neurotoxic and genotoxic potential of acrylamide has been established in freshwater fish, the full breadth of the toxicological consequences induced by this xenobiotic has not yet been disclosed, particularly in aquatic invertebrates. To assess the effects of acrylamide on a bivalve model, the Mediterranean mussel (Mytilus galloprovincialis), two different setups were accomplished: 1) acute exposure to several concentrations of waterborne acrylamide to determine lethality thresholds of the substance and 2) chronic exposure to more reduced acrylamide concentrations to survey phases I and II metabolic endpoints and to perform a whole-body screening for histopathological alterations. Acute toxicity was low (LC50≈400mg/L). However, mussels were responsive to prolonged exposure to chronic concentrations of waterborne acrylamide (1-10mg/L), yielding a significant increase in lipid peroxidation plus EROD and GST activities. Still, total anti-oxidant capacity was not exceeded. In addition, no neurotoxic effects could be determined through acetylcholine esterase (AChE) activity. The findings suggest aryl-hydrocarbon receptor (Ahr)-dependent responses in mussels exposed to acrylamide, although reduced comparatively to vertebrates. No significant histological damage was found in digestive gland or gills but female gonads endured severe necrosis and oocyte atresia. Altogether, the results indicate that acrylamide may induce gonadotoxicity in mussels, although the subject should benefit from further research. Altogether, the findings suggest that the risk of acrylamide to aquatic animals, especially molluscs, may be underestimated.
- Prevalence of quinolone resistance determinants in non-typhoidal Salmonella isolates from human origin in Extremadura, SpainPublication . Campos, Maria Jorge; Palomo, Gonzalo; Hormeño, Lorena; Herrera-León, Silvia; Domínguez, Lucas; Vadillo, Santiago; Píriz, Segundo; Quesada, AlbertoResistance to the quinolones nalidixic acid (NAL) and ciprofloxacin (CIP) and the occurrence of quinolone resistance determinants have been investigated in 300 non-typhoidal Salmonella from human origin, isolated in the years between 2004 and 2008, in 6 hospitals within Extremadura (Spain). Salmonella Enteritidis was the major serotype found among quinolone-resistant isolates, most of which were clustered by clonal analysis to a single clone, which presented D87 or S83 substitutions in GyrA. Eleven isolates presented the non-classical quinolone resistance phenotype (resistance to CIP and susceptibility to NAL), lacking mutations in the quinolone resistance determinant region of topoisomerase genes. Among them, one Salmonella Typhimurium isolate carried a qnrS1 gene in a low-molecular-weight plasmid, pQnrS1-HLR25, identical to plasmids previously found in the UK, Taiwan, and USA. The occurrence of this genetic element could represent a risk for the horizontal transmission of quinolone resistance among Enterobacteriaceae in the Iberian Peninsula.
- Synthesis and anion binding properties of new dihomooxacalix[4]arene diurea and dithiourea receptorsPublication . Marcos, Paula M.; Teixeira, Filipa A.; Segurado, Manuel A. P.; Ascenso, José R.; Bernardino, Raul J.; Brancatelli, Giovanna; Geremia, SilvanoFunctionalization of the lower rim of p-tert-butyldihomooxacalix[4]arene with two (thio)ureido moieties provided new diurea (n-propyl 5a, tert-butyl 5b and phenyl 5c) and dithiourea (phenyl 5d) derivatives, all in the cone conformation, as shown by NMR studies. The X-ray crystal structure of 5c is reported. The binding ability of these neutral receptors towards a large variety of anions was assessed by 1H NMR titrations. The structures and complexation energies of some complexes were also studied using DFT methods. The data showed that, in general, the association constants decrease with decrease of anion basicity and they are strongly dependent on the nature of the substituent at the urea moiety. Phenyl-(thio)urea derivatives 5c and 5d are the best anion receptors, showing the strongest complexation for F− (log Kass=2.70 and 2.75, respectively) and also for the oxoanions AcO−, BzO− and H2 PO4. These results were corroborated by DFT calculations.
- The use of cholinesterase as potential biomarker: In vitro characterization in the polychaete Capitella teletaPublication . Gomes, Isa D. L.; Lemos, Marco F. L.; Soares. Amadeu M. V. M.; Barata, Carlos; Faria, MelissaThe ecological relevance of polychaetes coupled with their easy culture and maintenance in the laboratory, has led them to become increasingly used in marine ecotoxicological studies, raising the need to validate frequently applied monitoring tools at various biological levels. The present study was aimed to characterize the cholinesterases (ChE) activity in the polychaete Capitella teleta, using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and four known inhibitors (eserine hemisulfate, BW284c51, iso-OMPA and chlorpyrifos-oxon). Results showed that most of the measured cholinesterase activity was acetylcholinesterase (AChE). Inhibition of enzyme kinetic experiments denoted that sensitivity of C. teleta’s ChE to the organophosphorous metabolite chlorpyrifos-oxon (IC50 = 60.72 nM) was analogous to some fish species. This study highlights the relevance of ChE characterization before its use as a biomarker in ecotoxicology and biomonitoring studies.
- Effects of Barcelona harbor sediments in biological responses of the polychaete Capitella teletaPublication . Gomes, Isa D. L.; Lemos, Marco F. L.; Soares, Amadeu M. V. M.; Díez, Sergi; Barata, Carlos; Faria, MelissaMarine ecosystems are increasingly exposed to a multitude of anthropogenic contaminants. Harbor environments are permanently subjected to such contaminants and bottomsediments are considered as the final repository. Filter-feeding and burrowing organisms, such as some polychaete communities, are among the most exposed organisms. This study aimed to assess the toxicity of Barcelona harbor sediments to the polychaete Capitella teleta by assessing and linking individual-level responses such as body weight (growth) and egestion rate (feeding) with subcellular-level responses including antioxidant (catalase and superoxide dismutase) and neurotransmission related (acetyl cholinesterase) enzyme activities. Sedimentswere collected fromthree different locations of the Barcelona (Spain) harbor with a positive gradient of metallic and organochlorine pollution from the mouth of the harbor towards the innermost zone. Sub-cellular and individual behavior of C. teleta exposed to Barcelona harbor sediments allowed the discrimination of toxic responses across sediments. Behavior responses were better correlated to chemical contamination than those of biomarkers. Harbor sediments produced neurotoxicity, promoted oxidative stress and reduced egestion and growth rates in exposed worms. These results indicate that biological responses of C. teleta worm can be used as early-warning tools to assess pollution effects on marine soft-bottom macrobenthonic communities.
- Temporal changes in macrofauna as response indicator to potential human pressures on sandy beachesPublication . Bessa, Filipa; Gonçalves, Sílvia C.; Franco, João N.; André, José N.; Cunha, Pedro P.; Marques, João CarlosSandy beaches are natural dynamic ecosystems, which are becoming worldwide increasingly disturbed by intensive human direct use, coastal development and erosive evolution. In this study, we have examined whether ten years of potential increased human pressures have resulted in significant changes in the macrofaunal assemblages’ structure and composition of two mesotidal sandy beaches (Cabedelo – urban beach, and Quiaios – rural beach) on the European Atlantic coast (Portugal). Seasonal macrofauna collections were performed at both beaches in two different periods, one in 1999–2000 and another in 2010–2011. The physical variables did not change significantly in both beaches throughout the studied periods, however, the urban beach was subject to an increase of human pressures (tourism and shoreline modifications) over the 10-years interval considered when compared with the rural beach. The univariate community descriptors (total density, species richness and diversity) did not differ significantly among periods for the rural beach. In contrast, temporal differences were found at the most urbanised beach, principally regarding the abundances of the amphipod Talitrus saltator and the isopod Tylos europaeus, two of the most abundant species at both beaches. PERMANOVA tests enhanced these temporal variations and the SIMPER analysis attributed to these species the main differences found between periods in this beach. Since the physical environment was similar in both periods, the ecological changes were most likely attributed to the increased human pressures observed at the urban beach. Nevertheless, this study highlights the need of further robust and effective impact assessments and long-term studies to better discern between natural and human induced changes on sandy beaches.
- Bidentate Urea Derivatives of p-tert-Butyldihomooxacalix[4]arene: Neutral Receptors for Anion ComplexationPublication . Marcos, Paula M.; Teixeira, Filipa A.; Segurado, Manuel A. P.; Ascenso, José R.; Bernardino, Raul J.; Michel, Sylvia; Hubscher-Bruder, VéroniqueThree new bidentate ureidodihomooxacalix[4]- arene derivatives (phenyl 5a, n-propyl 5b, and tert-butyl 5c) were synthesized in four steps from the parent compound ptert- butyldihomooxacalix[4]arene and obtained in the cone conformation, as shown by NMR studies. The binding ability of these neutral receptors toward spherical, linear, trigonal planar, and tetrahedrical anions was assessed by 1H NMR and UV-vis titrations. The structures and complexation energies of some complexes were also studied by DFT methods. The data showed that the association constants are strongly dependent on the nature of the substituent (aryl/alkyl) at the urea moiety. In general, for all the receptors, the association constants decrease with decrease of anion basicity. Ph-urea 5a is the best anion receptor, showing the strongest complexation for F- (log Kassoc = 3.10 in CDCl3) and also high binding affinity for the carboxylates AcO- and BzO-. Similar results were obtained by UV-vis studies and were also corroborated by DFT calculations.
- Preparation of Triacylglycerols Rich in Omega-3 Fatty Acids from Sardine Oil Using a Rhizomucor miehei Lipase: Focus in the EPA/DHA RatioPublication . Bispo, Paulo; Batista, Irineu; Bernardino, Raul J.; Bandarra, Narcisa MariaThe increasing evidence on the differential biochemical effects of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) raises the need of n-3 highly unsaturated fatty acid concentrates with different amounts of these fatty acids. In the present work, physicochemical and enzymatic techniques were combined to obtain acylglycerols, mainly triacylglycerols (TAG), rich in n-3 fatty acids. Sardine oil was obtained by washing sardine (Sardina pilchardus) mince with a NaHCO3 solution, hydrolyzed in a KOH-ethanol solution, and concentrated with urea. The esterification reaction was performed in the stoichiometric proportion of substrates for re-esterification to TAG, with 10 % level of Rhizomucor miehei lipase based on the weight of substrates, without any solvent, during 48 h. This procedure led to approximately 88 % of acylglycerols, where more than 66 % were TAG and the concentration of n-3 fatty acids was higher than 60 %, the EPA and DHA ratio (EPA/DHA) was 4:1. The content of DHA in the unesterifed fraction (free fatty acids) increased from 20 to 54 %, while the EPA level in the same fraction decreased from 33 to 12.5 % (EPA/DHA ratio ≈1:4). Computational methods (density functional theory calculations) have been carried out at the B3LYP/6-31G(d,p) level to explain some of the experimental results.