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The geochemical stability, in terms of potential mobility and derived ecological and human health risks of potentially toxic elements (PTEs), of diverse fresh and old porphyry Cu-mine tailings from Chile was assessed through an integrated methodology comprising four interrelated investigation levels: (1) chemical composition and contamination degree of tailings by PTEs, (2) mineralogical characterization by X-ray diffraction and quantitative automated mineralogy analysis by scanning electron microscopy (QEMSCAN®), (3) partitioning and potential mobility of PTEs within the tailings by a sequential extraction procedure (SEP) and leaching tests, and (4) ecological risk assessment (ERA) and human health risk assessment (HHRA). According to pollution indices, Cu, As, Pb, and Mo are most concerning PTEs present in the tailings. SEP shows that major portion of the PTEs are strongly fixed as residual fraction, and thus are poorly mobilizable and bioavailable. Among the PTEs, Cu, As, and Mo were identified as the PTEs most prone to mobilization. Leaching tests show that a low fraction of PTEs is water-leachable. Seawater enhances Mn and As leaching, while process water increases the leaching of Cu, Mn, and Mo. Phosphate particularly promotes leaching of As and Cu, whereas it does not mobilize or even immobilize Pb in the tailings. ERA suggests that mainly old tailings pose a very high potential risk for ecological receptors (PERI = 663-3356), mostly due to Cu and As. HHRA indicates that the old tailings pose higher potential non-carcinogenic and carcinogenic health risks, while the risk decreases in the order ingestion > dermal > inhalation for both children and adults. Non carcinogenic and carcinogenic HHRA points to As as the main PTE of concern via ingestion pathway in the tailings. Overall, the results revealed that particularly old tailings, containing mixed slag-tailings, pose considerable risks to the environment and human health due to potential PTEs mobilization and this aspect requires scrutiny for proper tailings management, including storage, sealing, and eventual tailings reprocessing and/or site rehabilitation after closure.

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RESUMO

Since the motivation to study and engage in academic activities plays a key role in students' learning experience and well-being, gaining a better understanding of dental students' motivations can help educators implement interventions to support students' optimal motivations. The aim of this study, grounded in self-determination theory, was to determine the predictive role of different types of motivation (autonomous motivation, controlled motivation, and amotivation) in the affective and behavioral outcomes of dental students. Amotivation is the absence of drive to pursue an activity due to a failure to establish relationships between activity and behavior; controlled motivation involves behaving under external pressure or demands; and autonomous motivation is an internalized behavior with a full sense of volition, interest, choice, and self-determination. A cross-sectional correlational study was conducted in 2016, in which 924 students (90.2% response rate) from years one to six agreed to participate, granting permission to access their current GPAs and completing four self-reported questionnaires on academic motivation, study strategies, vitality, and self-esteem. The results showed that self-determined motivation (i.e., autonomous over controlled motivation) was positively associated with vitality, self-esteem, and deep study strategies and negatively associated with surface study strategies. The contrary results were found for amotivation. In the motivational model, deep study strategies showed a positive association with students' academic performance. Contrary results were found for surface study strategies. This study extends understanding of the differentiation of motivation based on its quality types and suggests that being motivated does not necessarily lead to positive educational outcomes. Autonomous motivation, in contrast to controlled motivation and amotivation, should be supported to benefit students with regard to their approaches to learning and well-being since it can promote students' vitality, self-esteem, deep over surface study strategies, and enhanced academic performance.

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RESUMO

PURPOSE: Internalization of students' motivation towards an intrinsic form is associated with increased interest, commitment, learning, and satisfaction with education. Self-Determination theory postulates that intrinsic motivation and autonomous forms of self-regulation are the desired type of motivation; as they have been associated with deep learning, better performance and well-being. It claims three basic psychological needs have to be satisfied in order to achieve intrinsic motivation. These are the needs for autonomy, competence and relatedness. This study aims to provide a review on how these basic psychological needs are encouraged in undergraduate students so they can be transferred to the clinical teaching environment. METHODS: Electronic searches were performed across four databases (Medline, Embase, PsycINFO, and ERIC), relevant journals, and retrieved bibliography of selected articles. In total, searches produced 4,869 references, from which 16 studies met the inclusion criteria. RESULTS: Main themes were coded in three categories: The support of autonomy, competence and relatedness. The research-based evidence appears to be of reasonable quality, and indicates that teachers should work to satisfy students' basic psychological needs to foster internalization of self-regulation. Our findings suggest that teachers should interact with students in a more 'human centred' teaching style, as these actions predict motivational internalization. Several themes emerged from different contexts and further investigation should expand them. CONCLUSION: This review identified actions that clinical teachers could implement in their daily work to support students' self-determination. Autonomy supportive teaching in health professions educations would benefit students and may actually result in more effective health care delivery.