Browsing by Issue Date, starting with "2021-08-11"
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- Meditation effects on anxiety and resilience of preadolescents and adolescents: a randomized controlled studyPublication . Gomes, Alexandra; Santos, Joana; Vieira, Luís SérgioMeditation has been described as having a positive impact on well-being while reducing anxiety and stress among those who practice, mainly working as a resource to cope with everyday difficulties. As a simple and easy to apply meditation technique, transcendental meditation (TM) has shown promising results in adults and in children, although more studies are needed to show the impact on psychological and behavioral dimensions in children and adolescents. This quasi-experimental, pre-test–post-test study, with a control group, aimed to evaluate the impact of TM on the stress and resilience of children and adolescents, with ages between 9 and 16 years old. Participants were selected within schools which implemented the Quiet Time Program (QT), from those who volunteered to participate. They were randomly assigned to an experimental group (immediate TM learning) and to a control group (delayed TM learning). A repeated measures ANOVA showed an interaction of time and group on externalizing behavior, from the strengths and difficulties measure. The experimental group decreased on externalizing less adjusted behaviors, while the control group increased in this aspect, after a twelve-week period. TM failed to reduce anxiety and to contribute to resilience in the TM experimental group. Both groups improved anxiety indicators. The results might suggest students were acting upon their expectation of improvement on practicing TM or solely modifying their behavior along the contextual factors, which affected both groups equally.
- Toxic elements in soil and rice in EcuadorPublication . Atiaga, Oliva; Ruales, Jenny; Nunes, L.; Otero, Xosé LuisThe concentration of trace toxic metals (Cr, Zn, As, Pb, Cd, Cu, and Ni) in soil and rice plants, including the stems, leaves, and grain, from the main rice-producing provinces in Ecuador, was determined. Additionally, the soils were analyzed to determine their properties, composition, total content, bioavailable fraction, and geochemical fractions of toxic elements. Approximately 30% of soil samples in the case of Cr and Cu and 10% of samples in the case of Ni exceeded the legal thresholds for Ecuador. Moreover, for Cr and Cu, approximately 4% and 13% of samples, respectively, exceeded the threshold value of 100 mg kg−1 proposed for these two elements in several international regulations. Concentrations of As, Pb, and Cd in the soils were below the threshold values established both by Ecuadorian laws and by other countries. The concentrations of metals in rice plants did not correlate linearly with the total metal concentrations in the soil, nor with their bioavailability. However, the bioconcentration factors for As, Cd, Cu, Ni, and Zn could be predicted from bioavailability by a power law with exponents ranging from −0.724 to −1.625, which is typical of accumulator plants, where trace metal homeostasis plays an important role.