Extractability and mobility of mercury from agricultural soils surrounding industrial and mining contaminated areas

This study focussed on a comparison of the extractability of mercury in soils with two different contamination sources (a chlor-alkali plant and mining activities) and on the evaluation of the influence of specific soil properties on the behaviour of the contaminant. The method applied here did not target the identification of individual species, but instead provided information concerning the mobility of mercury species in soil. Mercury fractions were classified as mobile, semi-mobile and non-mobile. The fractionation study revealed that in all samples mercury was mainly present in the semi-mobile phase (between 63 and 97%). The highest mercury mobility (2.7 mg kg-1) was found in soils from the industrial area. Mining soils exhibited higher percentage of non-mobile mercury, up to 35%, due to their elevated sulfur content. Results of factor analysis indicate that the presence of mercury in the mobile phase could be related to manganese and aluminum soil contents. A positive relation between mercury in the semi-mobile fraction and the aluminium content was also observed. By contrary, organic matter and sulfur contents contributed to mercury retention in the soil matrix reducing the mobility of the metal. Despite known limitations of sequential extraction procedures, the methodology applied in this study for the fractionation of mercury in contaminated soil samples provided relevant information on mercury's relative mobility

Supervisão no ensino clínico no serviço de cirurgia: um estudo com alunos do 3º ano de enfermagem

A supervisão de estudantes de enfermagem em ensino clínico implica (re)pensar as práticas e aprofundar o processo formativo dos futuros enfermeiros, não só na dimensão científica da profissão, mas também no desenvolvimento de capacidades de análise crítico-reflexivas que contribuem para o seu desenvolvimento pessoal e profissional. Esta investigação sobre o processo supervisivo numa unidade hospitalar visou, entre outros objetivos: analisar as caraterísticas da reflexão desenvolvida por alunos de enfermagem durante o seu estágio no ensino clínico. Para a recolha destes dados foi utilizada a observação participante e instrumentos de supervisão tais como diários de sessões, semanários reflexivos, portefólios, estudos de caso, reflexões críticas no final do estágio e grelhas de avaliação intercalar e final. Os dados recolhidos durante o estágio clínico mostraram que os alunos de enfermagem: foram interiorizando as orientações, reajustaram comportamentos e posturas, progrediram gradualmente no seu desempenho e na aquisição de competências, e nas situações mais ansiogénicas o papel da supervisora foi fundamental. Também se verificou que a relação supervisiva foi baseada num clima afetivo-relacional positivo. Além disso, o semanário foi um instrumento importante no relato e expressão dos factos e opiniões publicamente difíceis de revelar. O estudo de caso foi valorizado por possibilitar uma reflexão sobre a prática enquanto a reflexão crítica final mostrou um confronto entre a identidade atual e as expetativas para a identidade do futuro enfermeiro. Os resultados evidenciaram a necessidade de aprofundar a investigação sobre os instrumentos de supervisão a utilizar no estágio em ensino clínico, para que este se torne eficaz no desenvolvimento pessoal e profissional dos futuros enfermeiros.The supervision of nursing students in clinical internship implies the (re)thinking of practices and a deepening of the training process for future nurses, not only in the scientific dimension of the profession but also in the development of critical-reflective analysis capacities which contribute to their personal and professional development. This research on the supervisory process in a hospital unit aims to accomplish the following aim, among others: to analyze the characteristics of nursing students' reflexions during their internship. Participant observation and supervisory tools such as daily sessions, weekly reflective diaries, portfolios, case studies, critical reflections at the end of the internship and intercalary and final evaluation grids were used for data collection. Data collected during the clinical internship of nursing students showed that: they were internalizing the guidelines, readjusting behaviours and attitudes, gradually they were progressing in their performance and skill acquisition and in anxiogenic situations the supervisor's role was considered essential. Also, the supervisory relationship was based on a positive relational and cultural climate. In addition, the weekly diary was an important tool in the narration and expression of the facts and opinions publicly difficult to reveal. The case study was valuable because it allowed for a reflection on practice while the final critical reflection showed a confrontation between the present and the expectations of the future identity of the nurse. These results highlighted the need for further research on supervisory tools to use in clinical internship in order for it to become effective in the personal and professional development of future nurses

Mitigation of Ochratoxin A in the food chain, from prevention to remediation

Mycotoxins are metabolites produced by a few filamentous fungi, that are ubiquitous in Nature, being found in many food crops. Their toxicity to humans demands a very strict control under a properly designed food safety program. Also, food losses due to fungal deterioration raise food security concerns. Mitigation actions to avoid or reduce human exposure to mycotoxins start in the field, where most mycotoxin producing fungi are active and mycotoxin accumulation starts. These actions include strategies to prevent mycotoxin-producing fungi from proliferating in the food or feed, to prevent these same fungi to produce the toxins, and to either remove, segregate or degrade the mycotoxins that have been produced. Using the case of ochratoxin A in our food, different strategies to mitigate contamination, from the screening of mycotoxigenic strains, integrated in a preventive approach, to the use of enzymes, as a remediation approach, will be discussed in this presentation. The screening of mycotoxin-producing strains will be discussed based on a microbiome approach, where the producing fungi may be spotted without their isolation, while the use of enzymes will be discussed along with a molecular modelling approach to elucidate enzymatic activity. The authors are grateful for the PhD support grants from the Portuguese Foundation for Science and Technology (FCT): 2020.05849.BD. (Teresa Vale Dias) and UI/BD/152286/2021 (Joana Santos).The authors are grateful for the PhD support grants from the Portuguese Foundation for Science and Technology (FCT): 2020.05849.BD. (Teresa Vale Dias) and UI/BD/152286/2021 (Joana Santos).info:eu-repo/semantics/publishedVersio

On the dynamics of a viral marketing model with optimal control using indirect and direct methods

The complexity of optimal control problems requires the use of numerical methods to compute control and optimal state trajectories for a dynamical system, aiming to optimize a particular performance index. Considering a real viral advertisement, this article compares the dynamics of a viral marketing epidemic model with optimal control under different cost scenarios and from two perspectives: using numerical methods based on the Pontryagin's Maximum Principle (indirect methods) and methods that treat the optimal control problem as a nonlinear constrained optimization problem (direct methods). Based on the trade-off between the maximization of information spreading and the minimization of the costs associated with it, an optimal control problem is formulated and studied. The existence and uniqueness of the solution are proved. Our results show not only that the cost of implementing control policies is a crucial parameter for the spreading of marketing messages, but also that low investment costs in control strategies fulfill the proposed trade-off without compromising the financial capacity of a company.Portuguese Foundation for Science and Technology (FCT – Fundação para a Ciência e a Tecnologia), through CIDMA – Center for Research and Development in Mathematics and Applications, within project UID/MAT/04106/2013; and through Algoritmi R&D Center, under COMPETE: POCI-01-0145-FEDER-007043 within the Project Scope: UID/CEC/00319/20

Significance of interactions between microplastics and POPs in the marine environment: a critical overview

The presence of plastic debris in the ocean is increasing and several effects in the marine environment have been reported. A great number of studies have demonstrated that microplastics (MPs) adsorb organic compounds concentrating them several orders of magnitude than the levels found in their surrounding environment, therefore they could be potential vectors of these contaminants to biota. However, a consensus on MPs as vectors of persistent organic pollutants (POPs) has not been reached since are opposing views among different researchers on this topic. However, all agree that more extensive studies are needed to clarify this relationship. This review reunites information reporting the factors that drive the sorption dynamics between MPs and POPs, which essentially corresponds to polymer properties and surrounding environmental variables. Furthermore, this review highlights several supporting and rebuttal arguments in the direction to clear up the real hazard enforced by the presence of MPs in marine environments.publishe

Desirability–doability group judgment framework for the collaborative multicriteria evaluation of public policies

Desirability–doability framework (2 × D) is a novel framework for the collaborative evaluation of public policies. Fundamental objectives and performance indicators are agreed upon in workshops, policies are characterised, and barriers to implementation identified. MACBETH interactive protocols are then applied in decision conferences to elicit qualitative judgments about the desirability of policies, within and across objectives; and about their doability under the expected graveness of barriers on contrasting scenarios. Elicited judgments allow, respectively, to construct a shared multicriteria model measuring the overall desirability of policies; and, to measure their doability. Desirability–doability graphs enable visual interactive classification of policies, with sensitivity/robustness analyses of uncertainties. 2 × D was successfully tested in a real-world urban-health policymaking case to evaluate spatial policies. The main novelty of 2 × D is that it bridges the socio-technical gap, present in OR, between the support required by a complex social decision-making process, and that usually offered by analytic techniques – while keeping modeling theoretically sound and simple

Improving antibiotic use through educational interventions

The growing rates of antimicrobial resistances demand the improvement of antibiotic use worldwide. The antibiotic misprescription by physicians, the antibiotic dispense without prescription by pharmacists, and the misuse by patients, are some of the most important factors underlying the increasing rates of antimicrobial resistances. Accordingly, it is of major importance to develop educational interventions targeting the different actors in the chain of antibiotic resistance, aiming to increase knowledge, understand attitudes and improve antibiotic use. In this chapter, readers can find a proposed design model which aims to improve the effectiveness of the educational interventions, presenting and developing each step that should be considered when implementing an educational intervention

Modelling multicriteria value interactions with Reasoning Maps

Idiographic causal maps are extensively employed in Operational Research to support problem structuring and complex decision making processes. They model means-end or causal discourses as a network of concepts connected by links denoting influence, thus enabling the representation of chains of arguments made by decision-makers. There have been proposals to employ such structures to support the structuring of multicriteria evaluation models, within an additive value measurement framework. However, a drawback of this multi-methodological modelling is the loss of richness of interactions along the means-end chains when evaluating options. This has led to the development of methods that make use of the structure of the map itself to evaluate options, such as the Reasoning Maps method, which employs ordinal scales and ordinal operators for such evaluation. However, despite their potential, Reasoning Maps cannot model explicitly value interactions nor perform a quantitative ranking of options, limiting their applicability and usefulness. In this article we propose extending the Reasoning Maps approach through a multilinear evaluation model structure, built with the MACBETH multicriteria method. The model explicitly captures the value interactions between concepts along the map and employs the MACBETH protocol of questioning to assess the strength of influence for each means-end link. The feasibility of the proposed approach to evaluate options and to deal with multicriteria interactions is tested in a real-world application to support the construction of a population health index