Partial molar volumes of glycine and L-Alanine in aqueous MgSO4 solutions between 278.15 and 308.15 K

In this work, partial molar volumes of glycine and L-alanine in aqueous solutions of magnesium sulphate at (0.0, 0.1, 0.3, 0.7 and 1.0) molal were obtained between 278.15 K and 308.15 K. Additionally, partial molar volumes of transfer at infinite dilution and hydration numbers were calculated. In general, transfer volumes are higher for glycine then L-alanine. From the transfer volumes, it can be concluded that the predominant interactions are pairwise between ions and zwitterionic centers of the amino acids. On the other hand, hydration numbers are higher for L-alanine than glycine. Dehydration of the studied amino acids is observed, rising either temperature or salt molality.This work is supported by project Project PEst-C/EQB/LA0020/2013, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundação para a Ciência e a Tecnologia. This work was also co-financed by QREN, ON2 and FEDER (Project NORTE-07-0162-FEDER-000050)

Responsive bystander behaviour in cyberbullying: a path through self-efficacy

Bystander behaviour and self-efficacy beliefs play an important role in cyberbullying incidence. This study tested the relationship between the Bystander Intervention Model phases and the mediating role of adolescents’ self-efficacy beliefs. Children from the fifth to twelfth grade (N = 676) participated in this study by responding to questionnaires concerning the various phases of the Bystander Intervention Model and self-efficacy beliefs to resolve cyberbullying-related problems. Through structural equation modelling, noticing an incident of cyberbullying had a direct and indirect effect on aggressive behaviour, and an indirect effect on reporting and problem-solving behaviour. The indirect effect of interpreting the event through attributing responsibility was significant for aggressive and problem-solving behaviour. The mediator role of reflective decision-making had a stronger effect on direct problem-solving. Self-efficacy beliefs significantly affected the relationship between interpreting the event and all behaviour, but stronger for direct problem-solving. These findings help explain empirically how bystanders respond to incidents of cyberbullying.info:eu-repo/semantics/acceptedVersio

Comparison of aerodynamic models for Vertical Axis Wind Turbines

Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple streamtube model, a double-multiple streamtube model, the actuator cylinder model, a 2D potential flow panel model, a 3D unsteady lifting line model, and a 2D conformal mapping unsteady vortex model. The comparison covers rotor configurations with two NACA0015 blades, for several tip speed ratios, rotor solidity and fixed pitch angle, included heavily loaded rotors, in inviscid flow. The results show that the streamtube models are inaccurate, and that correct predictions of rotor power and rotor thrust are an effect of error cancellation which only occurs at specific configurations. The other four models, which explicitly model the wake as a system of vorticity, show mostly differences due to the instantaneous or time averaged formulation of the loading and flow, for which further research is needed.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin

Dynamic separation on a pitching and surging airfoil as a model for flow over vertical axis wind turbine blades

Vertical axis wind turbine (VAWT) blades undergo dynamic separation due to the large angle of attack variation they experience during a turbine rotation. The flow over a single blade was modeled using a sinusoidally pitching and surging airfoil in a constant free stream flow at a mean chord Reynolds number of 10^5. Two-dimensional, time resolved velocity fields were acquired using particle image velocimetry (PIV). Vorticity contours were used to visualize shear layer and vortex activity. A low order model of dynamic separation was developed using Dynamic Mode Decomposition (DMD). A primary and secondary dynamic separation mode were identified as the critical drivers for the unsteady flow field

Cut-off points of the 1-minute sit-to-stand test to detect functional impairment and mortality risk in people with COPD

Introduction: Functional status is a key outcome in people with chronic obstructive pulmonary disease (COPD) and can be defined as an individual’s ability to perform normal daily activities required to meet basic needs, fulfill usual roles, and maintain health and well-being. The 1-minute sit-to-stand test (1-min STS) is a wellestablished measure to assess functional status in people with COPD that can be used in different settings (e.g., office, clinic, hospital, home) with limited resources (i.e., a chair and a stopwatch). This test is a strong predictor of exacerbations, hospitalizations and mortality in people with COPD. Yet, cut-off points to determine functional impairment with the 1-min STS in people with COPD are lacking for use in clinical practice. Recently, our group established a cut-off (19.5 repetitions) for increased mortality risk, however, it still lacks external validation. Objectives: To explore the predictive ability of the 1-min STS to detect functional impairment and the validity of the previously established cut-off for increased risk of mortality in people with COPD. Methods: A cross-sectional study was conducted with people with COPD. Age, sex, body mass index (BMI), lung function, the 1-min STS and the five-repetitions sit-to-stand tests were collected. We used two cut-offs for the five-repetitions sit-to-stand test known to be associated with low functional performance (12.1 seconds) and increased risk of mortality (15.98 seconds) in people with COPD. Receiver operating characteristics analysis (ROC) was performed and the area under the curve (AUC), sensitivity, specificity, and accuracy were calculated. The optimal cut-off points were identified by the highest Younden index. Results: In total, 302 people with COPD (67.5 ± 10.4 years; 79.1% male; BMI 26.7 ± 4.6 kg/m²; FEV1 55.2 ± 20.4%predicted) participated. Cut-off points in the 1-min STS of 23.5 repetitions for low functional performance (AUC = 0.92; 95%CI 0.89-0.95; 96.4% sensitivity; 80.9% specificity; accuracy = 0.84) and 18.5 repetitions for increased risk of mortality (AUC = 0.97; 95%CI 0.94-0.987; 95.5% sensitivity; 88.6% specificity; accuracy = 0.89) were found in people with COPD. Conclusions: The 1-min STS showed an outstanding discriminative ability and excellent accuracy in determining low functional performance and increased risk of mortality in people with COPD. A cut-off of 23.5 repetitions can be used to identify people with functional impairment. The cut-off point found for increased risk of mortality is similar to the previously published using the 6-minute walk test as an anchor, reinforcing the validity of this cut-off. These cut-offs support healthcare professionals in tailoring an appropriate management plan for this treatable trait and might possibly contribute to the implementation of timely preventive or palliative strategies.publishe

Octanol–water partition coefficients and aqueous solubility data of monoterpenoids: experimental, modeling, and environmental distribution

Terpenes and terpenoids encompass one of the most extensive and valuable classes of secondary metabolites. Their ten-carbon-containing oxygenated representatives, monoterpenoids, are the main components of plant essential oils, being widely exploited in the cosmetic, pharmaceutical, and food industrial areas. Due to its widespread use, it is crucial to investigate their environmental distribution. Thus, new water solubility data were obtained for six monoterpenoids ((1R)-(+)-camphor, (S)-(+)-carvone, eucalyptol, (1R)- (−)-fenchone, L-(−)-menthol, and (−)-menthone) at 298.2 and 313.2 K. Furthermore, octanol−water partition coefficients of 12 monoterpenoids (the six mentioned above plus carvacrol, (±)-β-citronellol, eugenol, geraniol, linalool, and thymol) were measured at 298.2 K. The COSMO-RS thermodynamic model and other more empirical approaches were evaluated for the description of the solubilities and partition coefficients, showing reliable predictions. Lastly, the distribution of the monoterpenoids in the different environmental compartments was assessed through an intuitive two-dimensional chemical space diagram based on the physicochemical equilibrium information reported.This work was developed within the scope of the project CIMO-Mountain Research Center, UIDB/00690/2020, and CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology (FCT)/MCTES. S.M.V.-B. thanks FCT and the European Social Fund (ESF) for his Ph.D. grant (SFRH/BD/138149/2018). M.C.d.C. would also like to thank CNPq (306666/ 2020-0) and FAPESP (2014/21252-0).info:eu-repo/semantics/publishedVersio

Grape pomace as a source of phenolic compounds and diverse bioactive properties

The bio-residues resulting from the wine industry (grape pomace made up of skins, seeds and stems) are often undervalued but constitute a potential source of bioactive phenolic compounds that can be applied in several industries. In this context, the aim of the present study was to evaluate the phenolic profile of Vitis vinifera L. grape pomace (skins, seeds and their mixture), and correlate them with its antioxidant, cytotoxic and antibacterial activities. The seeds showed the highest amount of phenolic compounds and also the highest antioxidant, cytotoxic and antibacterial activities. The skins revealed the highest levels of anthocyanins and pcoumaric acid hexoside. Strong correlations were observed between the presence of phenolic compounds and all the bioactivities studied. These by-products are good sources of phenolic compounds with high antioxidant and antibacterial activity, and also presenting a moderate cytotoxicity activity. These added-value by-products have great applicability in food, pharmaceutical and cosmetic industries.The authors thank the financial support to CIMO (UID/AGR/00690/ 2013) and Associate Laboratory LSRE-LCM, Instituto Politécnico de Bragança (project POCI-01-0145-FEDER-006984) funded by European Regional Development Fund (ERDF) through Programmes PT2020 and COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT – Fundação para a Ciência e a Tecnologia, also funding the contracts of R.C. Calhelha and L. Barros. To the FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Organomineral phosphorus fertilization in the production of corn, soybean and bean cultivated in succession.

The use of organic waste in agriculture has been used aiming at greater productivity, decrease in the cost of production and sustainable use of resources. The present study aimed at evaluating the effect of phosphate fertilization with the maintenance of organomineral fertilizers, combining poultry manure and soluble or reactive phosphate, in the production of grains in corn culture and the residual effect for subsequent crops of beans and soybeans. The experiment was conducted in Sete Lagoas, MG, in 2015, using three fertilizers with sources of different phosphorus sources (triple super phosphate?STP, organomineral with STP and organomineral with Bayovar phosphate) applied at the doses of 65, 130, 195 and 260 kg∙ha−1 of P2O5 total, and compared to the control without phosphate fertilization. We evaluated the contents of foliar P, P accumulation in the grains, yields of corn grains, beans and soy, accumulated productivity and export of accumulated P of the three cultures. The three cultures assessed presented higher productivity when compared to the average of the factorial treatments that received phosphate fertilization relative to the control. Organomineral fertilizers increased grain production, obtaining average productivity equal to or greater than those obtained with the exclusive use of STP