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Background Laccases and laccase-like multicopper oxidases (LMCOs) oxidize a vast array of phenolic compounds and amines, releasing water as a byproduct. Their low substrate specificity is responsible for their tremendous biotechnological interest, since they have been used for numerous applications. However, the laccases characterized so far correspond to only a small fraction of the laccase genes identified in fungal genomes. Therefore, the knowledge regarding the biochemistry and physiological role of minor laccase-like isoforms is still limited. Results In the present work, we describe the isolation, purification and characterization of two novel LMCOs, PcLac1 and PcLac2, from Pleurotus citrinopileatus. Both LMCOs were purified with ion-exchange chromatographic methods. PcLac2 was found to oxidize a broader substrate range than PcLac1, but both LMCOs showed similar formal potentials, lower than those reported previously for laccases from white-rot fungi. Proteomic analysis of both proteins revealed their similarity with other well-characterized laccases from Pleurotus strains. Both LMCOs were applied to the oxidation of ferulic and sinapic acid, yielding oligomers with possible antioxidant activity. Conclusions Overall, the findings of the present work can offer new insights regarding the biochemistry and variability of low-redox potential laccases of fungal origin. Low-redox potential biocatalysts could offer higher substrate selectivity than their high-redox counterparts, and thus, they could be of applied value in the field of biocatalysis.

The main focus of this paper is on uncertainties associated with the selection of the incoherency coefficient and apparent propagation velocity in the simulation of asynchronous seismic excitations based on the provisions of CEN [Comité Européen de Normalisation] (Eurocode 8: Design of structures for earthquake resistance—part 2: bridges, BS EN 1998-2:2005, Brussels, Belgium 2005). To this effect, the importance of utilizing appropriate values of these two parameters in the simulation of spatially varying seismic excitations is highlighted, and practice-oriented recommendations are provided for their selection. In addition, preliminary probability distributions are proposed for the consideration of the effect of uncertainty in the selection of the apparent propagation velocity for reliability (fragility) analyses. The effect of multi-support input motions on the seismic response of bridges is also discussed.

The spatial variation of the earthquake ground motion over short distances can significantly affect the dynamic response of large and extended engineered structures, especially on sites with inhomogeneity in surface geology and geometry. In current practices, such variation is taken into account in terms of coherency, a function of frequency and distance, established on an essentially empirical basis and difficult to extrapolate at different sites. Hence, a better understanding of its physical significance and its relationship with the underlying ground structure is indispensable. A two-dimensional dense array, deployed at the small and shallow Koutavos-Argostoli valley in Cephalonia, Greece, provided an abundance of data to study the stochastic characteristics of seismic ground motions over very short distances. A set of 46 magnitude 2–5 events at epicentral distances 0–200 km has been selected for the analysis. The lagged coherency of the S-wave dominating seismogram was computed for each station-pair within the array and was averaged over various distance intervals for the whole data set. The results indicate a lack of a clear dependence of the average coherency on the magnitude, back azimuth or site-to-source distance of the event. The most striking result concerns the influence of the site geometry: the coherency is systematically lower for the pairs aligned perpendicular to the axis of the valley (2D) compared to those aligned in the parallel direction. This finding is consistent with the dominance of valley-edge generated surface waves propagating from one edge to the other. The averaged coherency estimates are only weakly represented by the existing parametric models, indicating its strong site dependent nature.

Purpose The aim of the present study was to investigate the feasibility of polysaccharides production by selected basidiomycetes in submerged culture. Olive mill wastewater (OMWW) was also tested as a potential substrate for polysaccharides production by mushroom strains, focusing on the simultaneous degradation and valorization of the waste material. Methods The tested strains were grown in two different substrates, and after biomass harvesting, polysaccharides were isolated using two different methods. The extracellular polysaccharides were isolated from the culture broth, with ethanol precipitation. The isolated fractions were partially characterized with FT-IR spectroscopy. Results All three strains performed well in both substrates. Maximum degradation performance of OMWW was achieved by Ganoderma lucidum , achieving 19.4% phenols reduction together with 47.56% decolorization. The extracellular polysaccharides (EPS) produced by all strains were found to be richer in total glucans during growth in semi-synthetic medium, compared to growth in OMWW-based medium. In regard to biomass polysaccharides, Pleurotus ostreatus biomass was found to be richer in glucans, reaching 8.68% (w/w) total glucan content when grown in semi-synthetic medium and 7.58% (w/w) when grown in OMWW-based medium. After purification of biomass polysaccharides with two methods, the fraction with the highest glucan content was found to be the one from G. lucidum after growth in semi-synthetic medium cultures, with 49.1% (w/w) total glucans. FT-IR spectra of the isolated samples revealed the bands corresponding to α- and β-glucosidic bonds, but also the existence of protein contamination. Conclusions Purification of biomass polysaccharides with two distinct methods revealed that α-amylase and Sevag treatments failed to remove completely α-glucans and proteins respectively, leading to the suggestion that these two steps could be omitted without significant impact. Moreover, the results imply that the valorization of OMWW might be feasible with the use of mushroom strains, leading to the production of important products, such as glucans.

Over the past few decades, dark tourism has become increasingly popular. The level of participation of the dark tourist within a dark site underlies the variety of experiences that can be produced, depending on the type of audience engagement. This study attempts to design the discourse of a performance-based typology of dark tourism, built on the representations of tourists’ participation within the Netflix documentary series Dark Tourist. As screen tourism can influence behavior patterns, a typology of spectator, spect-actor, and actor roles is presented. En las últimas décadas, el turismo oscuro se ha vuelto cada vez más popular. El nivel de participación del turista dentro de un sitio oscuro subyace en la variedad de experiencias que se pueden producir, según el tipo de participación de la audiencia. Este estudio intenta diseñar el discurso de una tipología performativa del turismo oscuro, construida a partir de las representaciones de la participación de los turistas dentro de la serie documental de Netflix, Dark Tourist. Dado que el turismo de pantalla puede influir en los patrones de comportamiento, se presenta una tipología de roles de espectador, actor-espectador y actor.

Travel serves as a tool for inner transformation, and educational travel is one form of transformational travel. However, despite their recognition as a niche market, educational travelers, such as international students, continue to be understudied, especially from a gender perspective. As gendered differences are observed in tourism research and gender stereotypes originate from culture and family traditions, this study seeks to answer the following research question: How are gender stereotypes experienced within the context of international students’ mobility experience? This research examines the transmission and dynamics of gender stereotypes and its implication on international students’ mobility experience. It explores students’ interaction and level of involvement with gender stereotypes within different social and relational contexts, and the change processes as a result of these dynamics. Thirty-three in-depth semi-structured interviews were carried out with international students from several nationalities who have finished one of the three types of Master’s degree in Tourism, at the University of Girona, Spain. This paper indicates that (a) women and men are still associated under different gender stereotypes, (b) values originating from gender stereotypes evolve according to individuals’ socio-cultural interactions, and (c) these dynamics of gender stereotypes can be experienced under the role of the spectator, spect-actor, and actor.

The enzymatic factory of ligninolytic fungi has proven to be a powerful tool in applications regarding the degradation of various types of pollutants. The degradative potential of fungi is mainly due to the production of different types of oxidases, of which laccases is one of the most prominent enzymatic activities. In the present work, crude laccases from the supernatant of Pleurotus citrinopileatus cultures grown in olive oil mill wastewater (OOMW) were immobilized in crosslinked enzyme aggregates (CLEAs), aiming at the development of biocatalysts suitable for the enzymatic treatment of OOMW. The preparation of laccase CLEAs was optimized, resulting in a maximum of 72% residual activity. The resulting CLEAs were shown to be more stable in the presence of solvents and at elevated temperatures compared to the soluble laccase preparation. The removal of the phenolic component of OOMW catalyzed by laccase-CLEAs exceeded 35%, while they were found to retain their activity for at least three cycles of repetitive use. The described CLEAs can be applied for the pretreatment of OOMW, prior to its use for valorization processes, and thus, facilitate its complete biodegradation towards a consolidated process in the context of circular economy.

Xyloglucan is a complex polysaccharide, consisting of both hexoses and pentoses, and is considered a minor hemicellulose, present mainly in primary plant cell walls. Due to the complexity of the polymer, multiple enzymes, acting in synergy, are needed for its complete degradation. Xyloglucan-degrading enzymes have also been shown to act synergistically with enzymes acting on other lignocellulose polymers, since xyloglucan is often found complexed with other polysaccharides in plant cell walls. The present primer article aims at illustrating the literature gaps regarding the enzymology, structural biology, phylogenetics, and biochemistry of xyloglucan-degrading microbial enzymes. Moreover, mapping the synergistic relationships of xyloglucan-degrading enzymes with those acting on other polysaccharides could enable the design of efficient enzyme cocktails for the saccharification and valorization of xyloglucan-containing feedstocks in future biorefineries.

The boundaries between neurodevelopmental disorders are often indistinct, even among specialists. But do these boundaries exist, or do experts struggle to distinguish and categorize symptoms in order to arrive at a dominant diagnosis while comorbidity continually leaves questions about where each disorder ends and begins? What should be reconsidered? The introduction of the term ‘spectrum of neurodevelopmental disorders’ could pave the way for a re-appraisal of the clinical continuum of neurodevelopmental disorders. This study aims to highlight the problems that emerge in the field of the differential diagnosis of neurodevelopmental disorders and propose a renegotiation of the distinctiveness criteria.