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- 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.
- Application of optimal experimental design concept to improve the estimation of model parameters in microbial thermal inactivation kineticsPublication . Gil, Maria M.; Miller, Fátima A.; Silva, Cristina L. M.; Brandão, Teresa R. S.The estimation of model parameters with high precision is of major importance in mathematical predictions. If a mathematical model is properly chosen and if the primary objective is to improve parameter estimation, underlying statistical theories can be applied. Precision increases with the number of experimental points. However, and in many situations, maximum precision is attained when sampling consists of replicates of specific experimental points. Experimental conditions can be optimized using the D-optimal design concept based on minimization of the generalized variance of the parameter estimates. The objective of this work was to use this methodology for the design of experiments for microbial inactivation processes described by a Gompertz-based model under isothermal and non-isothermal conditions. The application of D-optimal design concept considerably improved parameters precision, when compared to the commonly used heuristic designs.
- Mechanisms of regulation of SNF1/AMPK/SnRK1 protein kinasesPublication . Crozet, Pierre; Margalha, Leonor; Confraria, Ana; Rodrigues, Américo; Martinho, Cláudia; Adamo, Mattia; Elias, Carlos A.; Baena-Gonzalez, ElenaTheSNF1(sucrosenon-fermenting1)-relatedproteinkinases1(SnRKs1)aretheplantorthologsofthebuddingyeastSNF1andmammalianAMPK(AMP- activatedproteinkinase).Theseevolutionarilyconservedkinasesaremetabolicsensorsthatundergoactivationinresponsetodecliningenergylevels.Uponactivation,SNF1/AMPK/SnRK1kinasestriggeravasttranscriptionalandmetabolicreprogramingthatrestoresenergyhomeostasisandpromotestolerancetoadverseconditions,partlythroughaninductionofcatabolicprocessesandageneralrepressionofanabolism.Thesekinasestypicallyfunctionasaheterotrimericcomplexcomposedoftworegulatorysubunits,βandγ,andanα-catalyticsubunit,whichrequiresphosphorylationofaconservedactivationloopresidueforactivity.Additionally,SNF1/AMPK/SnRK1kinasesarecontrolledbymultiplemechanismsthathaveanimpactonkinaseactivity,stability,and/orsubcellularlocalization.HerewewillreviewcurrentknowledgeontheregulationofSNF1/AMPK/SnRK1byupstreamcomponents,post-translationalmodifications,variousmetabolites,hormones,andothers,inanattempttohighlightboththecommonalitiesoftheseessentialeukaryotickinasesandthedivergencesthathaveevolvedtocopewiththeparticularitiesofeachoneofthesesystems.
- Impacts of the Invasive Seaweed Asparagopsis armata Exudate on Energetic Metabolism of Rock Pool InvertebratesPublication . Silva, Carla O.; Novais, Sara C.; Soares, Amadeu M. V. M.; Barata, Carlos; Lemos, Marco F. L.The marine red algae Asparagopsis armata is an invasive species gaining competitive advantage by releasing large amounts of toxic compounds to the surrounding invaded area. The main objective of this study was to evaluate the effects of this invasive seaweed on marine invertebrates by exposing the common prawn Palaemon elegans and the marine snail Gibbula umbilicalis to the exudate of this seaweed. The seaweed was collected and placed in a tank for 12 h in the dark in a 1:10 ratio. Afterwards the seawater medium containing the released secondary metabolites was collected for further testing. Lethal and sublethal effects of A. armata were investigated. Biochemical biomarker responses associated with energy metabolism (lactate dehydrogenase, LDH; electron transport system activity, ETS; lipid, protein and carbohydrate content) were analysed. The biomarker responses showed physiological status impairment of invertebrates after exposure to low concentrations of this algal exudate. The highest concentrations of exudate significantly increased lipid content in both organisms. In the shrimp, protein content, ETS, and LDH were also significantly increased. By contrast, these parameters were significantly decreased in G. umbilicalis. A behavioural impairment was also observed in G. umbilicalis exposed to A. armata exudate, reducing feeding consumption. These results represent an important step in the research of natural toxic exudates released to the environment and prospective effects of this seaweed in invaded communities under increasing global change scenarios.
- Lab Brazil: Parquear Bando digital annotation: on digital scores for collective performance interventions in public spacesPublication . Rosa, Thembi; Fernandes, CarlaParquear Bando is an urban intervention designed for up to 20 people to perform in urban city centres. While describing this urban intervention and analysing parts of the material available in the online pilot publication, we will discuss the limits and potentialities of a digitization process for this improvised performance. We question whether it would be possible to use digital annotations as support for future performances of this collective action without the physical presence of its facilitators but still maintaining the main concerns and principles of Parquear Bando. The three-day workshop shares the intervention’s most common structure and composes a performance to be shown in a selected place of each city. During the Motion Bank Lab Brazil 2019, we started to create a digital archive for the workshop with the aim of finding a consistent documentation model using video annotations, recording interviews and digitizing some of the choreographers’ notebooks. Beyond the digital archive of this urban intervention, we are also interested in making the score and movement principles of this piece available to other groups who could perform Parquear Bando in different contexts.
- An empirical analysis of Lisbon hotel room rates determinantsPublication . Gomes, Conceição; Lima Santos, Luís; Malheiros, CátiaThis study investigates the impact of several characteristics and attributes of hotels on room rates in one of the most visited cities in Europe. The research allows to compare, in a transparent way, findings of previous studies and promotes added value using for the first time the hedonic price model (HPM) in the hospitality industry in Lisbon, Portugal. Although hotel room price determinants have already been studied, in this study it was introduced physical variables and location variables all together, as well as it was added the variables relating to certain services offered. A significant impact on hotel prices by official stars and OTAs punctuation has been confirmed. In line with previous studies, an additional star and belonging to a chain allow the hotel to increase the price. In addition, other attributes, such as the distance of the hotel from the airport and the centre, have impact on hotel prices. The evidence that the existence of a spa and a pool influences hotel prices will support stakeholders in investment and management decision.
- Cholinesterase activity in the caddisfly Sericostoma vittatum: Biochemical enzyme characterization and in vitro effects of insecticides and psychiatric drugsPublication . Pestana, João L. T.; Novais, Sara C.; Lemos, Marco; Soares, Amadeu M. V. M.Sericostoma vittatum is a caddisfly species, endemic to the Iberian Peninsula, proposed as a biomonitor species for lotic ecosystems. Since inhibition of cholinesterases[U+05F3] (ChE) activity has been used to evaluate the exposure of macroinvertebrates to organophosphates and carbamate pesticides, this work intended to characterize the ChE present in this species so their activity can be used as a potential biomarker of exposure. Biochemical and pharmacological properties of ChE were characterized in this caddisfly species using different substrates (acetylthiocholine iodide, propionylthiocholine iodide, and butyrylthiocholine iodide) and selective inhibitors (eserine sulfate, BW284c51, and iso-OMPA). Also, the in vitro effects of two insecticides (carbaryl and chlorantraniliprole) and two psychiatric drugs (fluoxetine and carbamazepine) on ChE activity were investigated. The results suggest that S. vittatum possess mainly AChE able to hydrolyze both substrates acetylthiocholine and propionylthiocholine since: (1) it hydrolyzes the substrate acetylthiocholine and propionylcholine at similar rates and butyrylthiocholine at a much lower rate; (2) it is highly sensitive to eserine sulfate and BW284c51, but not to iso-OMPA; and (3) its activity is inhibited by excess of substrate, a characteristic of typical AChE. in vitro inhibitions were observed only for carbaryl exposure while exposure to chlorantraniliprole and to relevant environmental concentrations of psychiatric drugs did not cause any significant effect on AChE activity. This study suggests that AChE activity in caddisflies can indeed be used to discriminate the effects of specific insecticides in monitoring programs. The use of non-target species such as caddisflies in ecotoxicological research in lotic ecosystems is also discussed.
- How a Tourism City Responds to COVID-19: A CEE Perspective (Kraków Case Study)Publication . Kowalczyk-Anioł, Joanna; Grochowicz, Marek; Pawlusiński, RobertAcademic papers on the COVID-19 pandemic and tourism adopt the perspective of strengthening tourism resilience or recognize the ongoing crisis as an opportunity for reflection and the need to redefine tourism development strategies. This article examines these issues using the example of Kraków, a tourism city that, on the eve of the pandemic outbreak, was experiencing symptoms of overtourism. Using a case study approach, the authors illustrate the strategies applied at the city level, as well as the range of measures and actions used to support the tourism industry during the full pandemic year. The Kraków case shows that the pandemic time can be used to reorganize relations between local tourism stakeholders and to create a new formula for a tourism city in the so-called ‘new normal’. In addition, the exploratory case study allows for the formulation of research problems for further work on tourism cities responses to COVID-19. This can focus on a revision of the tourist offer and profile; the role of culture and the accompanying technology-facilitated innovations; the continuation of ‘being-a-tourist-in-your-own-city’, as promoted in the pandemic; tourists’ reactions to introduced changes; and shaping (new) relations between tourism stakeholders in the (post)pandemic city.