24 research outputs found

    Immobilization of the white-rot fungus Anthracophyllum discolor to degrade the herbicide atrazine

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    Herbicides cause environmental concerns because they are toxic and accumulate in the environment, food products and water supplies. There is a need to develop safe, efficient and economical methods to remove them from the environment, often by biodegradation. Atrazine is such herbicide. White-rot fungi have the ability to degrade herbicides of potential utility. This study formulated a novel pelletized support to immobilize the white-rot fungus Anthracophyllum discolor to improve its capability to degrade the atrazine using a biopurification system (BS). Different proportions of sawdust, starch, corn meal and flaxseed were used to generate three pelletized supports (F1, F2 and F3). In addition, immobilization with coated and uncoated pelletized supports (CPS and UPS, respectively) was assessed. UPS-F1 was determined as the most effective system as it provided high level of manganese peroxidase activity and fungal viability. The half-life (t1/2) of atrazine decreased from 14 to 6 days for the control and inoculated samples respectively. Inoculation with immobilized A. discolor produced an increase in the fungal taxa assessed by DGGE and on phenoloxidase activity determined. The treatment improves atrazine degradation and reduces migration to surface and groundwater.Grant CONICYT/FONDAP/15130015Grant FONDECYT 112096

    On conditional skewness with applications to environmental data

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    The statistical literature contains many univariate and multivariate skewness measures that allow two datasets to be compared, some of which are defined in terms of quantile values. In most situations, the comparison between two random vectors focuses on univariate comparisons of conditional random variables truncated in quantiles; this kind of comparison is of particular interest in the environmental sciences. In this work, we describe a new approach to comparing skewness in terms of the univariate convex transform ordering proposed by van Zwet (Convex transformations of random variables. Mathematical Centre Tracts, Amsterdam, 1964), associated with skewness as well as concentration. The key to these comparisons is the underlying dependence structure of the random vectors. Below we describe graphical tools and use several examples to illustrate these comparisons.The research of Félix Belzunce, Julio Mulero and José María Ruíz is partially funded by the Ministerio de Economía y Competitividad (Spain) under Grant MTM2012-34023-FEDER. Alfonso Suárez-Llorens acknowledges support received from the Ministerio de Economía y Competitividad (Spain) under Grant MTM2014-57559-P

    Shaping and Structuring Supramolecular Gels

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    Supramolecular gels assemble via non-covalent interactions between low-molecular-weight gelators (LMWGs). The gels form a solid-like nanoscale network spanning a liquid-like continuous phase, translating molecular-scale information into materials performance. However, gels based on LMWGs are often difficult to manipulate, easily destroyed and have poor rheological performance. The recurring image of newly-discovered supramolecular gels is that of an inverted vial showing that the gel can support its own weight against gravity. Such images reflect the limitation that these gels simply fill the vessel in which they are made, with limited ability to be shaped. This property prevents supramolecular gels from having the same impact as polymer gels, despite greater synthetic tunability, reversibility and bio/environmental compatibility. In this Review, we evaluate strategies for imposing different shapes onto supramolecular gels and for patterning structures within them. We review fabrication methods including moulding, self-healing, 3D printing, photopatterning, diffusion and surface-mediated patterning. We discuss gelator chemistries amenable to each method, highlighting how a multi-component approach can aid shaping and structuring. Supramolecular gels with defined shapes, or patterned structures with precisely-controlled compositions, have the potential to intervene in applications such as tissue engineering and nanoscale electronics, as well as opening-up new technologies

    The associated microflora to the larvae of human bot fly Dermatobia hominis L. Jr. (Diptera: Cuterebridae) and its furuncular lesions in cattle

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    The microflora associated to furuncular lesions, larvae and pupae of Dermatobia hominis, as well as the relationships between parasite, host and microflora associated, as a comprehensive microsystem, has been studied. One hundred and two furuncular myiasis due to D. hominis larvae in several breeds of cattle were studied and the following bacterial species were significant: Staphylococcus aureus, S. epidermidis, S. warneri, Bacillus subtilis and Escherichia coli. Closely related, the microflora associated to 141 samples from first, second, third instar larva and both external surface and larval cavities has been studied. The representative associated microflora to the larvae were: S. aureus, B. subtilis, S. hycus and Moraxella phenylpiruvica, Moerella wisconsiensis, Proteus mirabilis and P. vulgaris, M. phenylpiruvica, M. wisconsiensis, P. mirabilis and P. rettgeri were the representative microflora associated to 64 pupae of D. hominis

    Nutraceutical properties and phytochemical characterization of wild Serbian fruits

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    Wild fruits grown in Serbia, i.e., elderberry (Sambucus nigra), hawthorn (Crataegus monogyna), cornelian cherry (Cornus mas), and blackthorn (Prunus spinosa), are rich in secondary metabolites. In this study, the polyphenolic composition of wild fruit extracts and their antioxidant capacity were investigated by in vitro assays. Elderberry was characterized by the presence of arbutin (a skin protector), and cornelian cherry by syringic and gallic acids. In blackthorn, at least 11 different phenolic compounds were reported for the first time, including vanillic acid and naringin, the metabolite present in the highest amount. Blackthorn extracts were the richest in polyphenols (11.24-18.70g GAE/kgFW) and had the highest activity in the DPPH radical test (180.93-267.11mMTE/mL), while cornelian cherry extracts showed the most effective ferric ion chelating (81.37-90.66%) and antityrosinase inhibition capacities (21.75-74.23%). No sample was able to scavenge NO. Using the principal component analysis, wild fruit samples were classified into four separate clusters due to distinctive phenolic profiles and antioxidant capacity. Our investigation showed how every fruit could be considered unique in terms of its phytonutrient content. Thus, Serbian wild fruits may be a great source of bioactive natural compounds and could be therefore considered particularly useful in food supplement production. Particularly, as a source of natural antioxidants, these species could be used to extend the shelf life of food products and replace synthetic antioxidants, avoiding potential health risks and toxicity
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