1,055 research outputs found

    Overcoming Undergraduate Nursing Education Challenges During the Pandemic

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    Despite the challenges encountered throughout the COVID-19 pandemic, undergraduate nursing education was able to pivot and prevent cessation as faculty and students utilized various virtual platforms to provide didactic, skills lab, and clinical exposure without delaying graduation for many students. Although nothing could replace the hands-on human interaction a clinical rotation provided, virtual experiences aligned with the course content helped students reinforce the concepts taught in the corresponding didactic portion proving this to be beneficial in its own way. As faculty, we rose to the challenge in fostering a supportive environment to keep students motivated to learn and engaged in coursework

    Use of combined tools for effectiveness evaluation of tailings rehabilitated with designed Technosol

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    Soil and water characteristics and biogeochemical processes can be improved by the application of an integrated technology based on circular economy: designed Technosol. The evaluation of the effectiveness of the superficial application of a designed Technosol, with andic and eutrophic properties, on the rehabilitation of sulfide tailings of a uranium mine (Fe´ mining area, Spain) was the aim of this study. After 20 months of the Technosol application, the tailing rehabilitation status (Rehabilitated tailing) was compared to a non-rehabilitated tailing (Tailing). To assess the rehabilitation of these systems, several properties were analyzed: chemical characteristics of the materials and their leachates, soil enzymatic activities (dehydrogenase, b-glucosidase, acid phosphatase and urease), basal respiration and several plant endpoints from direct and indirect bioassays and pot experiment using Lolium perennse L. and Trifolium pratense L.. Potentially toxic concentrations of Co, Mn and Ni were identified in both available fraction and leachates, pointing out the serious environmental risk posed by the tailing. The improvement of overall physicochemical properties in the rehabilitated tailing materials (e.g., decrease of the hazardous element concentrations in leachates and available fraction, and improvement of the fertility and structure) allowed a quick plant cover with pasture species and provided a suitable habitat for active microbial community (evaluated by increasing dehydrogenase activity and basal respiration). This improvement in the rehabilitated tailing contributed to a significant decrease in the ecotoxicological risk and the spread of hazardous elements. The field application of this specific Technosol was a promising and lasting solution for rehabilitation of this type of tailingsinfo:eu-repo/semantics/publishedVersio

    Effects of organic/inorganic amendments on trace elements dispersion by leachates from sulfide-containing tailings of São Domingos mine, Portugal. Time evaluation

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    Greenhouse pot experiments were conducted over 13 months to evaluate the effect of two amendment mixture doses (30 and 75 Mg/ha) on the geochemical dispersion of trace elements by leaching hazardous mine wastes from the São Domingos mine. Mineralogical evolution of these materials was also evaluated. Amendment mixtures containing solid wastes from agriculture (plant remains + strawberry substrate and rockwool used for the strawberry crop) and fromdistillation of Ceratonia siliqua L. and Arbutus unedo L. fruitswere used to improve the chemical characteristics of leachates fromsulfide minewastes. Sulfide mine wastes had acidic characteristics, aswell as high electrical conductivity and total element concentrations (g/kg; Al: 54.8–61.2; Fe: 104.0–110.0; Pb: 9.0–13.8; S: 63.6–68.0; As: ≈1). These features contributed to the large capacity for leaching of hazardous elements during, at least, the first fourmonths of incubation. In the seventh month of incubation, therewas a significant decrease in the leachate concentration of the majority of hazardous elements. The addition of amendments minimised trace element dispersion in leachate percolation during the first seven months (25 to 99% reduction compared to control, depending on the element and sampling period). However, the leachate characteristics were not influenced by amendment doses and no significant differences were observed in leachate composition (control and amended treatments) after 13 months. Amendment application led to differences between the solid phases of the efflorescent salts formed on the surface of the control and the amended treatments. The efflorescent salts contained very soluble aluminium sulfates, together with alunite–jarosite-group solid phases in amended samples, and copiapite-group solid phases in control. In the core materials (5 to 10 cmin depth), themineralogy was similar in both control and amended samples. The presence of various stable solid phases from alunite– jarosite-group, such as jarosite and beudantite (mainly in deeper materials), can explain the low concentrations of trace elements in the leachates after thirteen monthsinfo:eu-repo/semantics/publishedVersio

    Influence of Seed Source and Soil Contamination on Ecophysiological Responses of Lavandula pedunculata in Rehabilitation of Mining Area

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    Mining activities have turned many areas of the Iberian Pyrite Belt (IPB) into extreme environments with high concentrations of metal(loid)s. These harsh conditions can inhibit or reduce the colonization and/or development of most vegetation. However, some species or populations have developed ecophysiological responses to tolerate stress factors and contaminated soils. The main objectives of this study are: (i) to assess the differences in germination, growth, development and physiological behaviour against oxidative stress caused by metal(loid)s in Lavandula pedunculata (Mill.) Cav. from two different origins (a contaminated area in São Domingos mine, SE of Portugal and an uncontaminated area from Serra do Caldeirão, S of Portugal) under controlled conditions; and (ii) to assess whether it is possible to use this species for the rehabilitation of mine areas of the IPB. After germination, seedlings from São Domingos (LC) and Caldeirão (L) were planted in pots with a contaminated soil developed on gossan (CS) and in pots with an uncontaminated soil (US) under controlled conditions. Multielemental concentrations were determined in soils (total and available fractions) and plants (shoots and roots). Germination rate, shoot height, dry biomass and leaf area were determined, and pigments, glutathione, ascorbate and H2O2 contents were measured in plant shoots. Total concentrations of As, Cr, Cu, Pb and Sb in CS, and As in US exceed the intervention and maximum limits for ecosystem protection and human health. The main results showed that L. pedunculata, regardless of the seed origin, activated defence mechanisms against oxidative stress caused by high concentrations of metal(loid)s. Plants grown from seeds of both origins increased the production of AsA to preserve its reduction levels and kept the contents of GSH stable to maintain the cell’s redox state. Plants grown from seeds collected in non-contaminated areas showed a high capacity for adaptation to extreme conditions. This species showed a greater growth capacity when seeds from a contaminated area were sown in uncontaminated soils. Thus, L. pedunculata, mainly grown from seeds from contaminated areas, may be used in phytostabilization programmes in areas with soils with high contents of metal(loid)sinfo:eu-repo/semantics/publishedVersio

    Aplicação de biorreatores no processo de biorremediação de solo contaminado por combustíveis

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    A biorremediação consiste em várias técnicas de recuperação de áreas contaminadas utilizando como base micro-organismos para degradar os compostos orgânicos contaminantes e transformá-los em compostos não nocivos. No presente trabalho foi estudada a aplicação de uma dessas técnicas, a bioestimulação, que visa aumentar a atividade microbiana da população nativa modificando determinados parâmetros do solo, como aeração, nutrientes e pH. Para avaliação da eficiência do tratamento por bioestimulação ex situ realizou-se um estudo de caso em um solo contaminado por gasolina coletado na área de um posto de combustível. Foram preparados quatro biorreatores aeróbios, onde dois deles receberam ajuste de nutrientes, pH e umidade e os outros dois tiveram somente a umidade corrigida. Durante 30 dias de experimentos, diversos parâmetros foram acompanhados semanalmente e, ainda, foram realizadas análises iniciais e finais de BTEX e PAH, em laboratório externo, para comparar a eficiência da remoção de matéria orgânica contaminante presente no solo, que foi de aproximadamente 97%

    The Potential of Cistus salviifolius L. to Phytostabilize Gossan Mine Wastes Amended with Ash and Organic Residues

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    The São Domingos mine is within the Iberian Pyrite Belt, a mining district with large concentrations of polymetallic massive sulfide deposits. Mine waste heaps are considered extreme environments, since they contain high total concentrations of potentially hazardous elements (PHE), which contribute to inhibiting the development of most plants. Autochthonous plant species, such as Cistus salviifolius L., are able to grow naturally in this degraded environment, and may contribute to minimizing the negative chemical impacts and improving the landscape quality. However, the environmental rehabilitation processes associated with the development of these plants (phytostabilization) are very slow, so the use of materials/wastes to improve some physicochemical properties of the matrix is necessary in order to speed up the process. This work studied the effectiveness of the phytostabilization with C. salviifolius of gossan mine wastes from the mine of São Domingos amended with organic and inorganic wastes in order to construct Technosols. The mine wastes have an acid pH ( 3.5), high total concentrations of PHE and low concentrations of organic C and available nutrients. The best vegetative development occurred without visible signs of toxicity in the Technosols containing a mixture of agriculture residues. These treatments allowed the improvement of the soil-plant system providing a better plant cover and improved several chemical properties of mine wastes, helping to speed up the environmental rehabilitationinfo:eu-repo/semantics/publishedVersio

    Antioxidant enzymes activity of Cistus ladanifer L. from areas non contaminated in trace elements

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    The aim of this study was to evaluate the antioxidant enzymes activity (catalase, per-oxidase and superoxide dismutase) and the concentrations of As, Cu, Pb and Zn in leaves from two populations of Cistus ladanifer growing on soils non-contaminated with trace elements (Caldeirão and Pomarão), but with different climatic conditions and in two different seasons (spring and summer). In both areas, total and available concentra-tions (DTPA extraction) of trace elements in soils were low. The distribution of elements for young and mature leaves was similar be-tween areas and seasons. The enzyme activi-ties varied with the plant population. Leaves collected in the two seasons, except young leaves from Pomarão collected in summer, showed enzymatic activity in the soluble and ionic fractions. Comparing the seasons and sampling areas, C. ladanifer enzymatic ac-tivities represent a tolerance mechanism to different stress factors (UV radiation, high air temperature in summer, drought, low-medium fertility in soils, trace element con-centrations in soil), giving it a high plasticit
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