184 research outputs found

    Coastal Cliff Exposure and Management

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    [Abstract:] Coastal cliffs cover about 75% of the world's coastlines. Many of these cliffs suffer severe erosion problems, which are mainly caused by wave action and lead to important damages. The main objective of this work is to propose and apply a methodology to characterize and map wave exposure levels for the management of cliff coasts. The methodology proposed consists of a number of steps. First, a statistical characterization of the wave climate in deep water is performed. Second, relevant sea states are propagated towards the cliff by means of a numerical model. Then, the results are used to assess the distribution of significant wave heights and wave power along the cliff toe. Finally, four exposure levels are defined based on the wave power values at the cliff, and exposure zones are mapped accordingly along the cliff. This approach is illustrated with a case study – the Catedrales Cliffs and Beach, a tourism hotspot in Galicia (NW Spain) where erosion caused loss of human life. We find that exposure levels are primarily influenced by the nearshore bed morphology, which controls wave refraction, shoaling and breaking, as well as by the geometry and orientation of the cliff, with some parts more exposed than others to the prevailing wave direction. On the islets off the cliff the windward faces have a greater level of exposure, since the leeward faces are protected by the islets themselves and lower water depths. The rocky outcrops that occur at the cliff toe in some sections act as emerged (submerged) breakwaters under low (high) tide conditions, dissipating wave power and thus reducing wave exposure. The methodology proposed in this work enables coastal managers to prevent the personal and material damages derived from cliff erosion by focusing remedial measures where they are most needed.Ministerio de Ciencia, Innovación y Universidades; FJCI-2017-3178

    Sagittal spinal curvatures and pelvic inclination in kayakers

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    El objetivo del estudio fue comparar la disposición sagital del raquis e inclinación pélvica en diferentes posiciones en kayakistas. A ciento treinta kayakistas entre 15 y 20 años (62 varones y 68 mujeres) se les evaluó, mediante un Spinal Mouse, la disposición angular del raquis torácico, lumbar e inclinación pélvica en bipedestación, sedentación relajada, máxima flexión del tronco en sedentación, test sit-and-reach, posición de base y de ataque en un kayak-ergómetro. La cifosis torácica en la piragua fue menor (p<0,001) que en bipedestación y sedentación relajada. El raquis lumbar se dispuso en inversión lumbar en las posturas de flexión del tronco y sedentación, favorecido por una posición de retroversión pélvica. Las mujeres adoptaron posturas de menor flexión lumbar y pélvica en el kayak-ergómetro. En conclusión, la posición de las mujeres en el kayak-ergómetro se caracteriza por posturas más alineadas del raquis y pelvisThe aim of this study was to compare the sagittal spinal curvatures and pelvic tilt in different positions on kayakers. One hundred and thirty kayakers between 15 and 20 years (62 males and 68 females) participated in this study. Thoracic and lumbar curvatures and pelvic position were evaluated with a Spinal Mouse system in standing position, slumped sitting, maximal trunk bending with knees flexed, sit-and-reach test, base position right entry position and left entry position in a kayak ergometer. Thoracic kyphosis in the kayak-ergometer was more reduced (p<0,001) than standing and slumped sitting. Lumbar spine adopted kyphotic postures when maximal trunk flexion was performed and in the kayak ergometer. This posture was related to posterior pelvic tilt. Females showed lower lumbar and pelvic flexion than males in the kayak ergometer. In conclusion, females adopt more aligned spinal and pelvic postures in the kayak ergometer than malesEste estudio se realizó en el marco de las ayudas de la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (II PCTRM 2007-2010) al proyecto nº 11951/PI/09, titulado “Evolution of sagittal spinal curvatures, hamstring extensibility, low back pain, and anthropometric characteristics in elite paddlers

    Crossflow microfiltration of fungal fermentation broths to obtain natural extracts

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    Motivation: One of the main milestones after developing a laboratory scale product is to transform the acquired knowledge into an economic production structure. The production of natural extracts in BioflowSur is carried out by using a fermentation process; then, natural extracts are separated from the fungus by vacuum filtration. However, this type of filtration is not feasible with large volumes so that the use of tangential microfiltration with membrane technology was studied.Methods: The fungal fermentation broth was filtrated using a bench-scale crossflow filtration unit (Prozesstechnik GmbH) equipped with a ceramic membrane either of 0,2 μm pore diameter (with active layer) or 5-8 μm pore diameter (without active layer). Two modes of operation were used: concentration and diafiltration. In the first mode the product concentrates in small volumes and in the second mode water is added to facilitate the filtration [1].Results: The diafiltration was discarded as mode of operation after the first test due to the generation of large volumes that complicate the subsequent extraction of the active principle. In addition, results reveal that the optimal temperature is 30ºC because higher temperatures facilitate the passage of residues to the permeate.The concentration tests performed with the membrane of 0.2 μm showed that there was active principle in the concentrate and in the permeate, while the membrane of 5-8 μm allowed fungus to pass to the permeate after several rounds of filtration. In addition, the high pressures generated due to the fouling drastically reduced the flow and, hence, increased the time of the process [2]

    Microwave-assisted extraction of sulfated fucans from brown seaweed and evaluation of fungal strains for enzymesactive production toward this class of polysaccharide

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    Sulphated polysaccharides from brown seaweedss comprise a complex group of macromolecules with a wide range of important biological properties such as anticoagulant, antioxidant, antiproliferative, antitumoral, anticomplementary, anti-inflammatory, antiviral, antipeptic and antiadhesive activities. Fucoidan is one of the main sulphated fucan, mostly interesting for their biological activities specially the potential to inhibit HIV reverse transcriptase and the possible application as active compound in antiretroviral drugs. However, algae remain largely unexploited and seaweeds can be found in sufficient amount for the commercial exploitation. Usually, most of the processes to recover sulfated polysaccharides from natural sources consist in acid extractions during long reaction times. Specific enzymes able to degrade fucoidan matrix (fucoidanases) are important tools to establish structural characteristics and biological functions of this polysaccharide. Such enzymes, have been only isolated from marine organisms. Reports of fungal microorganisms with enzymatic activity over this sulfated-polysaccharide are scarce. The aims of the present work were: 1) to recovery of sulphated polysaccharides (fucoidan) by microwave-assisted extraction under different operational conditions and 2) the identification of fungal strains able to growth over fucoidan-based media and to produce active fucoidanases

    Extraction of sulfated polysaccharides by autohydrolysis of brown seaweed Fucus vesiculosus

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    The extraction of sulfated polysaccharides (fucoidan) by autohydrolysis (AH) of brown seaweed Fucus vesiculosus was studied. Experimental assays were performed under different conditions of temperature (160 to 200°C) and reaction time (10 to 30 min) according to a 22 central composite design, and the conditions able to maximize the fucoidan yield were selected. The alga degradation and the total sugar yield in the liquor after AH were also determined to each experimental condition. The highest fucoidan yield (∼16.5% w/w) was obtained when the AH process was performed at 180°C for 20 min. This product was characterized by high-performance liquid chromatography, infrared analysis spectroscopy, and thermal gravimetric analyses, which verified the presence of fucose and galactose as main components (70:30% mol ratio, in average) and an SO3 content higher than 20%. AH process under optimum reaction conditions was an effective method to recover fucoidan from F. vesiculosus. The use of this technology brings also important advantages from economical and environmental viewpoints since it does not require the use of chemical solvent and generates less waste when compared to conventional extraction procedures.R.M. Rodriguez-Jasso would like to thank the Mexican Science and Technology Council (CONACYT, Mexico) for Ph.D. fellowship support (grant number 213592/308679). The authors also thank Professor Isabel Sousa Pinto, Rita Araujo PhD from CII-MAR, University of Porto, and Bartolomeu de Souza PhD for the collaboration during the selection and collection of the seaweed used in this study

    Efecto de un programa de intervención sobre el estrés percibido, autoestima y rendimiento en jóvenes pilotos de motociclismo de elite

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    In the motorcycling sport specialty, scientific literature has focused on technology, safety or even on injury variables; however there is little information regarding psychological variables. The aim of our study was to evaluate the effect of a technical and physical intervention on psychological variables such as self-esteem, self-assessment, appraisal of others and, finally, performance. The sample was made up of twenty-seven young elite road-race motorcyclists who competed in the Red Bull Moto GP Rookies Cup. 16 of whom completed an intervention program (Experimental Group, EG), while the other 14 belonged to the Control Group (CG). We collected the measurements in the first and last race of the season. Our results indicate the EG had controlled the stress level, had a better technique, physical, and psychological conditions, besides better competition performance, in comparison with the CG. We conclude that our intervention program has been effective at maintaining stress levels, bettering technical, tactical and psychological skills, and also improving performance throughout the competition period

    Enhancement of fructosyltransferase and fructooligosaccharides production by A. oryzae DIA-MF in Solid-State Fermentation using aguamiel as culture medium

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    The aim of this work was to improve the production of fructosyltransferase (FTase) by Solid-State Fermentation (SSF) using aguamiel (agave sap) as culture medium and Aspergillus oryzae DIA-MF as producer strain. SSF was carried out evaluating the following parameters: inoculum rate, incubation temperature, initial pH and packing density to determine the most significant factors through Box-Hunter and Hunter design. The significant factors were then further optimized using a Box-Behnken design and response surface methodology. The maximum FTase activity (1347 U/L) was obtained at 32 °C, using packing density of 0.7 g/cm3. Inoculum rate and initial pH had no significant influence on the response. FOS synthesis applying the enzyme produced by A. oryzae DIA-MF was also studied using aguamiel as substrate.Authors thank National Council for Science and Technology (CONACYT) of Mexico by the financial support through the project No. CB-2011-C01-167764. Author D. B. Muñiz-Márquez also thank CONACYT for the financial support during her postgraduate program (Doctorate) in Food Science and Technology offered by the University Autonomous of Coahuila, Mexico

    Typical Mexican agroindustrial residues as supports for solid-state fermentation

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    Biological wastes contain several reusable substances of high value such as soluble sugars and fiber. Direct disposal of such wastes to soil or landfill causes serious environmental problems. Thus, the development of potential value-added processes for these wastes is highly attractive. These biological wastes can be used as support-substrates in Solid-State Fermentation (SSF) to produce industrially relevant metabolites with great economical advantage. In addition, it is an environment friendly method of waste management. In this study were analyzed six different Mexican agro industrial residues to evaluate their suitability as support-substrate in SSF, between physicochemical properties that have included Water Absorption Index (WAI), Critical Moisture Point (CHP) and Packing Density (PD). The selection of an appropriate solid substrate plays an important role in the development of an efficient SSF process. The results provided important knowledge about the characteristics of these materials revealing their potential for use in fermentation processes.(undefined

    Gallic acid production with mouldy polyurethane particles obtained from solid state culture of Aspergillus niger GH1

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    Gallic acid production in a batch bioreactor was evaluated using as catalytic material the mouldy polyurethane solids (MPS) obtained from a solid-state fermentation (SSF) bioprocess carried out for tannase production by Aspergillus niger GH1 on polyurethane foam powder (PUF) with 5 % (v/w) of tannic acid as inducer. Fungal biomass, tannic acid consumption and tannase production were kinetically monitored. SSF was stopped when tannase activity reached its maximum level. Effects of washing with distilled water and drying on the tannase activity of MPS were determined. Better results were obtained with dried and washed MPS retaining 84 % of the tannase activity. Maximum tannase activity produced through SSF after 24 h of incubation was equivalent to 130 U/gS with a specific activity of 36 U/mg. The methylgallate was hydrolysed (45 %) in an easy, cheap and fast bioprocess (30 min). Kinetic parameters of tannase self-immobilized on polyurethane particles were calculated to be 5 mM and 04.1×102 mM/min for K M and V max, respectively. Results demonstrated that the MPS, with tannase activity, can be successfully used for the production of the antioxidant gallic acid from methyl-gallate substrate. Direct use of PMS to produce gallic acid can be advantageous as no previous extraction of enzyme is required, thus reducing production costs.Authors thank the National Council for Science and Technology (CONACYT-Mexico) for the financial support. The present work was performed as part of a cooperative agreement between DIA-Universidad Autonoma de Coahuila (Mexico) and IBB-Universidade do Minho (Portugal) within a specific training stay undertaken at the DEB-UM. Part of the research was funded by a project SEP-CONACYT-CB-2011
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