Antecedentes de la Economía Colaborativa en un Escenario de Pandemia: Actitudes Pro-sociales, Comportamientos Pasados y Expectativas de Transformación

[EN] 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.[ES] 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.This research is financed by national funds through FCT – Foundation for Science and Technology under the project UIDB/04630/2020

The role of bacteria in pine wilt disease: insights from microbiome analysis.

Pine Wilt Disease (PWD) has a significant impact on Eurasia pine forests. The microbiome of the nematode (the primary cause of the disease), its insect vector, and the host tree may be relevant for the disease mechanism. The aim of this study was to characterize these microbiomes, from three PWD-affected areas in Portugal, using Denaturing Gradient Gel Electrophoresis, 16S rRNA gene pyrosequencing, and a functional inference-based approach (PICRUSt). The bacterial community structure of the nematode was significantly different from the infected trees but closely related to the insect vector, supporting the hypothesis that the nematode microbiome might be in part inherited from the insect. Sampling location influenced mostly the tree microbiome (P < 0.05). Genes related both with plant growth promotion and phytopathogenicity were predicted for the tree microbiome. Xenobiotic degradation functions were predicted in the nematode and insect microbiomes. Phytotoxin biosynthesis was also predicted for the nematode microbiome, supporting the theory of a direct contribution of the microbiome to tree-wilting. This is the first study that simultaneously characterized the nematode, tree and insect-vector microbiomes from the same affected areas, and overall the results support the hypothesis that the PWD microbiome plays an important role in the disease's development

Anaerobic digestion of OMW : intermittent feeding strategy and LCFA oxidation profile

ManuscriptAn intermittent feeding strategy was applied to the anaerobic treatment of raw olive mill wastewater (OMW). Two reactors were operated under influent concentrations of 5 to 50 g COD L-1. Two and one batch (feed-less) periods were applied to reactor R1 and R2, respectively, operating in continuous thenceforth. It was demonstrated that the intermittent feeding of OMW improved the mineralization of accumulated Long Chain Fatty Acids (LCFA) inside the reactor. Nevertheless, LCFA accumulated again when the organic loading rate was increased from 2 to 3 and 5 kg COD m-3 d-1. The profiles of LCFA, obtained with OMW digestion, were different from previous studies with synthetic effluents. At the beginning of reactors operation, oleate was the main LCFA compound (~50%) followed by palmitate. Afterwards, a shift in the LCFA pattern accumulation was noticed for both reactors. At periods with higher OMW concentrations (30-50 g COD L-1, 3-5 kg COD m-3 d-1) palmitate was the main LCFA accumulated with 69% at R1 and 54% at R2. For real oily wastewaters, a periodically batch period could be a practical solution to maintain low values of LCFA inside the reactor. The addition of a nitrogen source was essential to enhance the methane yield

Strategies for lipids and phenolics degradation in the anaerobic treatment of olive mill wastewater

Strategies are proposed for the anaerobic treatment of lipid and phenolic-rich effluents, specifically the raw olive mill wastewater (OMW). Two reactors were operated under OMW influent concentrations from 5 to 48 g COD L-1 and Hydraulic Retention Time between 10 and 5 days. An intermittent feeding was applied whenever the reactors showed a severe decay in the methane yield. This strategy improved the mineralization of oleate and palmitate, which were the main accumulated Long Chain Fatty Acids (LCFA), and also promoted the removal of resilient phenolic compounds, reaching remarkable removal efficiencies of 60% and 81% for two parallel reactors at the end of a feed-less period. A maximum biogas production of 1.4 m3 m-3 d-1 at an Organic Loading Rate of 4.8 kg COD m-3 d-1 was obtained. Patterns of individual LCFA oxidation during the OMW anaerobic digestion are presented and discussed for the first time. The supplementation of a nitrogen source boosted immediately the methane yield from 21 and 18 to 76 and 93% in both reactors. The typical problems of sludge flotation and washout during the anaerobic treatment of this oily wastewater were overcome by biomass retention, according to the Inverted Anaerobic Sludge Blanket (IASB) reactor concepts. This work demonstrates that it is possible to avoid a previous detoxification step by implementing adequate operational strategies to the anaerobic treatment of OMW.The authors acknowledge the financial support of the “Fundação para a Ciência e a Tecnologia”, FCT/MCTES, through the project PTDC/ENR/69755/2006 and also through the grants given to Marta Gonçalves SFRH/BD/40746/2007 and José Carlos Costa SFRH/BDP/ 48962 /2008. The authors thank Tânia Ferreira for the help in LCFA analysis and Ana Cavaleiro for her scientific support

Photocurable Polymeric Blends for Surgical Application

The preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by 1H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives.info:eu-repo/semantics/publishedVersio

Angolan cymbopogon citratus used for therapeutic benefits: nutritional composition and influence of solvents in phytochemicals content and antioxidant activity of leaf extracts

Folk medicine is a relevant and effective part of indigenous healthcare systems which are, in practice, totally dependent on traditional healers. An outstanding coincidence between indigenous medicinal plant uses and scientifically proved pharmacological properties of several phytochemicals has been observed along the years. This work focused on the leaves of a medicinal plant traditionally used for therapeutic benefits (Angolan Cymbopogon citratus), in order to evaluate their nutritional value. The bioactive phytochemical composition and antioxidant activity of leaf extracts prepared with different solvents (water, methanol and ethanol) were also evaluated. The plant leaves contained ~60% of carbohydrates, protein (~20%), fat (~5%), ash (~4%) and moisture (~9%). The phytochemicals screening revealed the presence of tannins, flavonoids, and terpenoids in all extracts. Methanolic extracts also contained alkaloids and steroids. Several methods were used to evaluate total antioxidant capacity of the different extracts (DPPH; NO; and H2O2 scavenging assays, reducing power, and FRAP). Ethanolic extracts presented a significantly higher antioxidant activity (p < 0.05) except for FRAP, in which the best results were achieved by the aqueous extracts. Methanolic extracts showed the lowest radical scavenging activities for both DPPH; and NO; radicals

Concurrent training in prepubertal children: an update

This paper affords an update review over the state of art regarding the importance of physical fitness and the significance of different combination approaches between resistance and aerobic training, as well as conditioning methods exercise alone on physical fitness improvements, specifically explosive strength and cardiorespiratory fitness in prepubertal children. The main research conclusions can be summarized as: i) Resistance training can be reliable to improve muscle strength in prepubertal children; ii) A proper and quantifiable exercise frequency and intensity in aerobic training remains unclear; iii) No differences have been found between prepubertal girls and boys on strength and aerobic capacity improvements after intra-session concurrent training, resistance or aerobic training alone; iv) In adults, concurrent resistance and aerobic training seems to be more effective on improvements of aerobic capacity than aerobic training alone; v) Aerobic training biomechanically specific to the concurrent resistance training may minimize adaptation interference when concurrently training; vi) In adolescents, concurrent resistance and aerobic training is equally effective to improve explosive strength compared to resistance training alone, and more efficient in aerobic capacity than resistance training alone; vii) Optimum training sequence was determined by the individual purposes of the training program; viii) Performing aerobic prior to resistance training produces endurance gains, while performing resistance prior to aerobic training appears to be more adequate to obtain strength improvements; ix) In adults, performing concurrent training in different sessions seems to be more effective to improve muscular strength than intra-session concurrent training. These results can be helpful for coaches, teachers and researchers to optimize explosive strength and cardiorespiratory fitness training in sports club and school-based programs, as well as a reliable source for further researches

Modeling fitness variable responses to training In prepubescent children

The aim of this study was to determine strength and oxygen uptake (VO2max) performances according to different training program intervention design with 8-weeks duration in prepubescent children through a multiple linear regression models. Two hundred and forty-five healthy prepubescent children (aged 10.9 ± 0.5 years) were randomly assigned to a specific training program (strength training only - S; aerobic training only - A; intra-session aerobic and strength training - AS; intra-session strength and aerobic training - SA; or concurrent training performed in different sessions - CT) or a control group (no training regimen - C). It was possible to develop indirect predictive models for each training method, by including each variable pre-training, body fat percentage and body mass index. The models provided explained 82% of variance in the VO2max, 98% in the 1kg ball-throw, 96% in the 3kg ball-throw, 92% in the counter-movement jump, 93% in the standing long jump and 98% in the 20m sprint performances. This novel approach to training evaluation and control aims to provide a tool to allow professionals to calculate changes with a high confidence level (CI 95%), to control gains and to choose the best training methodology to apply according to the defined purposes. The results of this study could be a great support to teachers, coaches and professionals providing important tools to improve the efficacy and individualization of training

The influence of patterned nanofiber meshes on human mesenchymal stem cell osteogenesis

A specially designed electroconductive collector enables the electrospinning of P-NFM composed of areas of parallel/uniaxially aligned fibers and areas of random/orthogonal nanofiber distribution. The biological relevance of P-NFM is demonstrated using hBMSCs as an autologous cell source. The structures induce cell orientation along the uniaxially aligned fibers, mainly during earlier culturing periods under basal and osteogenic differentiation conditions. The microtopography of the P-NFM also controls the deposition of mineralized extracellular matrix along the pre-defined fiber direction. Genotypic characterization confirms the successful differentiation into the osteogenic lineage.European Integrated Project GENOSTEM (LSH-STREP-CT-2003-503161); European Network of Excellence EXPERTISSUES (NMP3-CT-2004-500283); Portuguese Foundation for Science and Technology for the project Naturally Nano (POCI/EME/58982/2004) and the PhD grant SFRH/BD/24382/2005

Modelling the tumour microenvironment in long-term microencapsulated 3D co-cultures recapitulates phenotypic features of disease progression

3D cell tumour models are generated mainly in non-scalable culture systems, using bioactive scaffolds. Many of these models fail to reflect the complex tumour microenvironment and do not allow long-term monitoring of tumour progression. To overcome these limitations, we have combined alginate microencapsulation with agitation-based culture systems, to recapitulate and monitor key aspects of the tumour microenvironment and disease progression. Aggregates of MCF-7 breast cancer cells were microencapsulated in alginate, either alone or in combination with human fibroblasts, then cultured for 15 days. In co-cultures, the fibroblasts arranged themselves around the tumour aggregates creating distinct epithelial and stromal compartments. The presence of fibroblasts resulted in secretion of pro-inflammatory cytokines and deposition of collagen in the stromal compartment. Tumour cells established cell–cell contacts and polarised around small lumina in the interior of the aggregates. Over the culture period, there was a reduction in oestrogen receptor and membranous E-cadherin alongside loss of cell polarity, increased collective cell migration and enhanced angiogenic potential in co-cultures. These phenotypic alterations, typical of advanced stages of cancer, were not observed in the mono-cultures of MCF-7 cells. The proposed model system constitutes a new tool to study tumour-stroma crosstalk, disease progression and drug resistance mechanisms