51 research outputs found

    Antecedents of the Sharing Economy in a Pandemic Scenario: Prosocial Attitudes, Past Behaviour and Transformation Expectations

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    The COVID-19 pandemic is expected to have a significant impact on most sharing economy activities, and at present, it is particularly challenging to achieve a consensual model to predict sharing economy behaviour. Based on empirical and theoretical premises established before the pandemic, we intend to explore the association between a set of psychosocial variables (i.e., cooperation, environmental awareness, past behaviour) and sharing economy behaviour, particularly the use of shared assets (i.e., cars and accommodation) during the COVID-19 pandemic. Furthermore, the present study analyses the mediating role of transformation expectations, as the decision to engage or not in sharing behaviour may be influenced by beliefs about the consequences of those actions from the user’s perspective. This study comprised a total of 596 participants. Data was collected through a self-administered questionnaire and was statistically analysed and interpreted using PLS 3.0. Structural Equation Modelling statistical software. Contrary to our predictions, the results show that cooperation negatively influenced the willingness to participate in sharing activities during the COVID-19 pandemic, that environmental awareness was not a significant predictor, and that past sharing behaviour has the strongest influence on the willingness to share during pandemic times. Finally, the mediating effect of transformation expectations was significant in both associations, i.e., pro-environmental consciousness and past sharing experiences, and the willingness to adopt sharing behaviour during COVID-19.Se espera que la pandemia de COVID-19 tenga un impacto importante en la mayoría de las actividades de la economía colaborativa, y en la actualidad, es particularmente difícil lograr un modelo consensual para predecir el comportamiento de la economía colaborativa. Sobre la base de premisas empíricas y teóricas establecidas antes de la pandemia, pretendemos explorar la asociación entre un conjunto de variables psicosociales (es decir, cooperación, consciencia ambiental, comportamiento pasado) y el comportamiento de la economía colaborativa, en particular el uso de activos compartidos (automóviles y alojamiento), durante la pandemia de COVID-19. Además, el presente estudio analiza el papel mediador de las expectativas de transformación, ya que la decisión de participar o no en el comportamiento de compartir puede estar influenciada por creencias sobre las consecuencias de esas acciones desde la perspectiva del usuario. Este estudio comprendió un total de 596 participantes. Los datos se recopilaron a través de un cuestionario autoadministrado y se analizaron e interpretaron estadísticamente utilizando el PLS 3.0., un software estadístico de modelación de ecuaciones estructurales. Contrariamente a nuestras predicciones, los resultados muestran que la cooperación influyó negativamente en la voluntad de participar en actividades compartidas durante la pandemia de COVID-19, que la conciencia ambiental no fue un predictor significativo y que el comportamiento de compartir en el pasado tiene la influencia más fuerte en la voluntad de compartir durante tiempos de pandemia. Finalmente, el efecto mediador de las expectativas de transformación fue significativo en ambas asociaciones, es decir, la conciencia proambiental y las experiencias pasadas de intercambio, y la disposición a adoptar un comportamiento de intercambio durante COVID-19.info:eu-repo/semantics/publishedVersio

    Occurrence, nanofiltration treatment and toxicity screening

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    Funding Information: This work was also funded by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior ( FCT / MCTES , Portugal) through national funds to iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020) and the Associate Laboratory LS4FUTURE (LA/P/0087/2020). Teresa I.A. Gouveia and Vanessa Jorge Pereira would like to thank the Portuguese Foundation for Science and Technology ( FCT ) for Ph.D. ( SFRH / BD /147301/2019) and CEECIND/02919/2018 grants, respectively. Funding Information: This research was financially supported by: (i) Project POCI-01-0145-FEDER-031297 (CytoStraTech)—funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT /MCTES; (ii) NORTE-01-0145-FEDER-000069 (Healthy Waters) co-funded by European Regional Development Fund ( ERDF ), through North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement; (iii) UIDB/04750/2020 (EPIUnit) and LA/P/0064/2020 (ITR), funded by national funds through the FCT - Foundation for Science and Technology, I.P.; (iv) LA/P/0045/2020 (ALiCE), Base Fundings UIDB/00511/2020 and UIDP/00511/2020 (LEPABE) and UIDB/50020/2020 and UIDP/50020/2020 (LSRE- LCM ), funded by national funds through FCT / MCTES (PIDDAC). Publisher Copyright: © 2023 The AuthorsAntineoplastic drugs are pharmaceuticals that have been raising concerns among the scientific community due to: (i) their increasing prescription in the fight against the disease of the twentieth century (cancer); (ii) their recalcitrance to conventional wastewater treatments; (iii) their poor environmental biodegradability; and (iv) their potential risk to any eukaryotic organism. This emerges the urgency in finding solutions to mitigate the entrance and accumulation of these hazardous chemicals in the environment. Advanced oxidation processes (AOPs) have been taken into consideration to improve the degradation of antineoplastic drugs in wastewater treatment plants (WWTPs), but the formation of by-products that are more toxic or exhibit a different toxicity profile than the parent drug is frequently reported. This work evaluates the performance of a nanofiltration pilot unit, equipped with a Desal 5DK membrane, in the treatment of real WWTP effluents contaminated (without spiking) with eleven pharmaceuticals, five of which were never studied before. Average removals of 68 ± 23% were achieved for the eleven compounds, with decreasing risks from feed to permeate for aquatic organisms from receiving waterbodies (with the exception of cyclophosphamide, for which a high risk was estimated in the permeate). Aditionally, no significative impact on the growth and germination of three different seeds (Lepidium sativum, Sinapis alba, and Sorghum saccharatum) were determined for permeate matrix in comparison to the control.publishersversionpublishe

    Rheotaxis in Larval Zebrafish Is Mediated by Lateral Line Mechanosensory Hair Cells

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    The lateral line sensory system, found in fish and amphibians, is used in prey detection, predator avoidance and schooling behavior. This system includes cell clusters, called superficial neuromasts, located on the surface of head and trunk of developing larvae. Mechanosensory hair cells in the center of each neuromast respond to disturbances in the water and convey information to the brain via the lateral line ganglia. The convenient location of mechanosensory hair cells on the body surface has made the lateral line a valuable system in which to study hair cell damage and regeneration. One way to measure hair cell survival and recovery is to assay behaviors that depend on their function. We built a system in which orientation against constant water flow, positive rheotaxis, can be quantitatively assessed. We found that zebrafish larvae perform positive rheotaxis and that, similar to adult fish, larvae use both visual and lateral line input to perform this behavior. Disruption or damage of hair cells in the absence of vision leads to a marked decrease in rheotaxis that recovers upon hair cell repair or regeneration

    Genetic variability in the tolerance of natural populations of Simocephalus vetulus (Müller, 1776) to lethal levels of sodium chloride

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    Using several clonal lineages of Simocephalus vetulus (Cladocera, Daphniidae) as a random sample, we investigated the genetic component of the halotolerance of one brackish and two freshwater populations of this littoral filter feeder. We hypothesized that genotypes from the brackish population were more tolerant than freshwater ones, via adaptation to local environmental conditions. Clonal identity was established by a cost-effective molecular fingerprinting technique (microsatellite-primed polymerase chain reaction (MSP-PCR)). Two distinct methodologies were used to assess cladoceran sensitivity to syntheticgrade sodium chloride (NaCl): (i) standard 48-h acute assays and (ii) 12-h survival time (ST) trials. No correlation was found between acute EC50 and ST values. The sensitivity of brackish and freshwater clones was comparable in terms of acute EC50 (varied from 2.28 to 3.83 g.Lx1). On the contrary, genetically determined differential tolerance to NaCl among populations was found for ST: all brackish genotypes, except one, were more resilient (ST>120 min) than freshwater clones (ST<120 min). Bearing in mind that these results were obtained with isolates from the extant population, it is surprising that the range of acute sensitivity of the freshwater and brackish genotypes was similar, and that the only difference between them was the ability of brackish clones to survive longer under high salinity stress (6 g.Lx1, in ST trials). We must conclude that the effect of salinity (original environment context) on the selection of genotypes was weaker than we had expected and than other authors have shown for other stressors.publishe

    Competitive outcome of Daphnia-Simocephalus experimental microcosms: salinity versus priority effects

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    Competition is a major driving force in freshwaters, especially given the cyclic nature and dynamics of pelagic food webs. Competition is especially important in the initial species assortment during colonization and re-colonization events, which depends strongly on the environmental context. Subtle changes, such as saline intrusion, may disrupt competitive relationships and, thus, influence community composition. Bearing this in mind, our objective was to assess whether low salinity levels (using NaCl as a proxy) alter the competitive outcome (measured as the rate of population biomass increase) of Daphnia-Simocephalus experimental microcosms, taking into account interactions with priority effects (sequential species arrival order). With this approach, we aimed to experimentally demonstrate a putative mechanism of differential species sorting in brackish environments or in freshwaters facing secondary salinization. Experiments considered three salinity levels, regarding NaCl added (0.00, 0.75 and 1.50 g L(-1)), crossed with three competition scenarios (no priority, priority of Daphnia over Simocephalus, and vice-versa). At lower NaCl concentrations (0.00 and 0.75 g L(-1)), Daphnia was a significantly superior competitor, irrespective of the species inoculation order, suggesting negligible priority effects. However, the strong decrease in Daphnia population growth at 1.50 g L(-1) alleviated the competitive pressure on Simocephalus, causing an inversion of the competitive outcome in favour of Simocephalus. The intensity of this inversion depended on the competition scenario. This salinity-mediated disruption of the competitive outcome demonstrates that subtle environmental changes produce indirect effects in key ecological mechanisms, thus altering community composition, which may lead to serious implications in terms of ecosystem functioning (e.g. lake regime shifts due to reduced grazing) and biodiversity
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