821 research outputs found

    Study of the optical behavior of skins using Monte Carlo techniques

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    Uno de los principales retos en óptica biomédica y en biofotónica es la simulación de la propagación de la luz en los tejidos biológicos. El método de Monte Carlo es la aproximación más empleada, y se puede afirmar que constituye un estándar por su flexibilidad y fiabilidad en modelar la geometría de un tejido heterogéneo. Este trabajo muestra cómo analizar el comportamiento óptico de la piel y cómo algunas de las deducciones extraídas de este análisis pueden aportar información para el diagnóstico y el tratamiento de pieles. Se han aplicado las propiedades ópticas de pieles sanas de diferentes razas y, como alteración posible en la piel, se ha estudiado la presencia del basalioma. Los resultados nos ofrecen un método para distinguir entre piel «sana» y piel «enferma», lo que podría facilitar un procedimiento de identificación de pieles cancerígenas. Del estudio de los distintos tipos de pieles sanas se desprende, además, un ejemplo de aplicación inmediata que se beneficia del conocimiento adquirido por los valores obtenidos (fotodepilación). En este trabajo se presentan los resultados más significativos de los programas de simulación basados en técnicas de Monte Carlo, que permiten estudiar el comportamiento de la piel frente a una radiación óptica. La aproximación a la trayectoria que sigue la luz en su interacción con el tejido se obtiene a partir de las propiedades ópticas conocidas a priori. Se realiza una aproximación general al tema, identificando los principales problemas que se plantean en este tipo de estudios y se emplea un programa comercial.In both biomedical optics and biophotonics, one of the main challengers is the simulation of light spread in biological tissues. The approximation which is most used is Monte Carlos method; it is a standard because of its flexibility and its reliability modeling heterogeneous tissues. This paper shows how to analyse the optical behaviour of the skin, and how some of the deductions drawn from this analysis can add information for the diagnosis and treatment of skins. The optic qualities of healthy skins from different races have been applied; and as a possible alteration in the skin, basalioma presence has been studied. The results provide us with a method to distinguish between “healthy” and “ill” skin, which could make the procedure to identify cancer skins easier. From the study of the different healthy skins an example of immediate application also appears which benefits from the knowledge acquired from the values obtained (photodepilation). In this work the most valued results of the simulation programs based in Monte Carlos technics are presented, which allow studying the skins behaviour facing an optical radiation; the approximation to the light trajectory interacting with the tissues is obtained from the optic qualities known before. First of all, a general approach to the theme is carried out, identifying the main problems that appear in this kind of studies and a commercial programme is used.Peer Reviewe

    Assessment of the methane emission for different typologies of fattening swine facilities in the department of Antioquia – Colombia

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    The explosive growth of swine production at high stocking densities in confinement farming worldwide, has raised concerns the environmental impact, health and livestock productivity and the production of associated gases in this type of large-scale farms. The aim of this paper was to study the methane gas concentration and emissions of ten different typologies of swine production installations. The facilities were in the department of Antioquia - Colombia, they were located between 800–2,300 meters above sea level (m.a.s.l.) of heights, they mainly employed natural ventilation as refrigeration strategy and they were used for pigs in fattening stage. Methane measurements were taken at animal height. Sensors were located at intermediate points of the ventilation inlet and outlet areas. The behaviour of methane concentration and emission of the facilities were analysed along with the correlation and temporal evolution of climatic variables, comfort indices and construction typologies. The information was analysed using descriptive statistics, analysis of variance (ANOVA) and principal component analysis (PCA). Were found an average of CH4 Emission Rate (ER) per facility (kg year-1 ) of 607.9, Global Warming Potential (GWP) per facility (kg year-1 ) of 15,197.42 and significant correlations between ER and cleaning frequency (CF), animal unit (AU), air flow (Q), animal density(AD) and relative humidity (RH) were evidenced. This is the first research reported in Colombia, that will be important to create some governmental policies

    A systematic literature review on the semi-automatic configuration of extended product lines

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    Product line engineering has become essential in mass customisation given its ability to reduce production costs and time to market, and to improve product quality and customer satisfaction. In product line literature, mass customisation is known as product configuration. Currently, there are multiple heterogeneous contributions in the product line configuration domain. However, a secondary study that shows an overview of the progress, trends, and gaps faced by researchers in this domain is still missing. In this context, we provide a comprehensive systematic literature review to discover which approaches exist to support the configuration process of extended product lines and how these approaches perform in practice. Extend product lines consider non-functional properties in the product line modelling. We compare and classify a total of 66 primary studies from 2000 to 2016. Mainly, we give an in-depth view of techniques used by each work, how these techniques are evaluated and their main shortcomings. As main results, our review identified (i) the need to improve the quality of the evaluation of existing approaches, (ii) a lack of hybrid solutions to support multiple configuration constraints, and (iii) a need to improve scalability and performance conditions

    Aquaculture as a circular bio-economy model with Galicia as a study case: How to transform waste into revalorized by-products

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    Background: World-wide aquaculture represents a very important sector capable of supplying huge amounts of animal protein. However its relevance has proportionally augmented its waste generation. In Europe, the geographical constitution of Galicia has prompted the instauration of many aquaculture-based systems along its coasts. Indeed aquaculture means a very relevant industry in Galicia, together with animal farming, agriculture and biotechnology. Scope and approach: Over the last decade Europe legislation encourages the proper management of wastes (mostly reutilization and reducing strategies) and the sustainable use of natural resources. The application of circular bio-economy (reuse of wastes) represents a feasible model to protect human and animal health and the environment. To achieve a more efficient production system that complies with European regulations, aquaculture wastes and sub-products need to be re-utilised to increase their throughput. This approach will positively impact on their economical yield while reducing their generation and thus protecting health and environment. Key findings and conclusions: Different applications have been considered for re-using aquaculture wastes and sub-products. One of the most efficient approaches is the establishment of models that allow the metabolic waste reduction, as the integrated multi-trophic aquaculture. For derived aquaculture sub-products, the most efficient process is recovering important biomolecules such as proteins (collagen, gelatine), polysaccharides (chitosan), lipids (omega 3) or pigments (astaxanthin or beta-carotene). Biomolecules can further be applied for human and animal consumption, food industry, cosmetics or pharmaceuticals. Due to the importance of this productive system in Galicia it is critical its update to include aquaculture into circular bio-economy.The research leading to these results received institutional and financial support from: Programa de Cooperaci´on Interreg V-A España—Portugal (POCTEP) 2014–2020 (projects Ref.: 0181_NANOEATERS_01_E and Ref: 0377_IBERPHENOL_6_E); Spanish Ministry of Economy, Industry and Competitiveness through the project AGL2015–67039–C3–1–R; MICINN supporting the Ram´on&Cajal grant for M.A. Prieto (RYC-2017-22891); Xunta de Galicia and University of Vigo for supporting the post-doctoral grant of María Fraga Corral (ED481B-2019/096) and the pre-doctoral grants of Antía Gonz´alez Pereira (ED481A-2019/0228) and P. García-Oliveira (ED481A-2019/ 295); Xunta de Galicia through the program EXCELENCIA-ED431F 2020/12 and the project ED431B 2019/24; Ibero-American Program on Science and Technology (CYTED - AQUA-CIBUS, P317RT0003); Axudas Conecta Peme (Xunta de Galicia) supporting the IN852A 2018/ 58 NeuroFood Project; AlgaMar (www.algamar.com); EcoChestnut Project (Erasmus+ KA202); Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBIJTI- 2019), the JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium. Funding for open access charge: Universidade de Vigo/ CISUG.info:eu-repo/semantics/publishedVersio

    Upper critical field Hc2H_{c2} calculations for the high critical temperature superconductors considering inhomogeneities

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    We perform calculations to obtain the Hc2H_{c2} curve of high temperature superconductors (HTSC). We consider explicitly the fact that the HTSC possess intrinsic inhomogeneities by taking into account a non uniform charge density ρ(r)\rho(r). The transition to a coherent superconducting phase at a critical temperature TcT_c corresponds to a percolation threshold among different superconducting regions, each one characterized by a given Tc(ρ(r))T_c(\rho(r)). Within this model we calculate the upper critical field Hc2H_{c2} by means of an average linearized Ginzburg-Landau (GL) equation to take into account the distribution of local superconducting temperatures Tc(ρ(r))T_c(\rho(r)). This approach explains some of the anomalies associated with Hc2H_{c2} and why several properties like the Meissner and Nernst effects are detected at temperatures much higher than TcT_c.Comment: Latex text, add reference

    Quality of the Physical Education Teacher's Instruction in the Perspective of Self-Determination.

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    The teacher's instructions in physical education class have important implications for the psychological well-being of their students. The aim of this study was to analyze, under the postulates of the Self-Determination Theory (SDT), a model with the following sequence: the perception of the quality of the instructions (task presentation, amount of corrective feedback, and its legitimate perception) generated by the physical education teacher, the satisfaction of the three basic psychological needs and the subjective vitality in young students. The participants were 890 students (462 males and 428 females) of primary level from the metropolitan area of Monterrey, Mexico, between ages 11 and 13 (M = 11.36; SD = 0.49). The structural equation modeling showed positive and significant associations in all model interrelations, that is, task presentation and the amount of corrective feedback (B = 0.88, p < 0.001), and this in turn with legitimate perception (B = 0.81, p < 0.001); the legitimate perception of feedback and the satisfaction of the need for autonomy, competence, and relatedness (B = 0.63, p < 0.001; B = 0.90, p < 0.001; B = 1.01, p < 0.001, respectively); finally, the satisfaction of the three psychological needs and the subjective vitality (B = 0.12, p < 0.01; B = 0.43, p < 0.001; B = 0.24, p < 0.001, respectively). Therefore, the importance of a quality task presentation, as well as providing corrective feedback based on support for autonomy, is evident, so that students perceive it legitimately and thus facilitate the satisfaction of their basic psychological needs and in consequence, indicators of psychological well-being such as subjective vitality

    Barriers to ecological restoration in Europe: expert perspectives

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    Ecological restoration is key to counteracting anthropogenic degradation of biodiversity and to reducing disaster risk. However, there is limited knowledge of barriers hindering the wider implementation of restoration practices, despite high-level political priority to halt the loss of biodiversity. In Europe, progress on ecological restoration has been slow and insufficient to meet international agreements and comply with European Union Nature Directives. We assessed European restoration experts' perceptions on barriers to restoration in Europe, and their relative importance, through a multiple expert consultation using a Delphi process. We found that experts share a common multi-dimensional concept of ecological restoration. Experts identified a large number of barriers (33) to the advancement of ecological restoration in Europe. Major barriers pertained to the socio-economic, not the environmental, domain. The three most important being insufficient funding, conflicting interests among different stakeholders, and low political priority given to restoration. Our results emphasize the need to increase political commitment at all levels, comply with existing nature laws, and optimize the use of financial resources by increasing funds for ecological restoration and eradicate environmentally harmful subsidies. The experts also call for the integration of ecological restoration into land-use planning and facilitating stakeholders' collaboration. Our study identifies key barriers, discusses ways to overcome the main barriers to ER in Europe, and contributes knowledge to support the implementation of the European Biodiversity Strategy for 2030, and the EU 2030 Restoration Plan in particular. © 2021 The Authors. Restoration Ecology published by Wiley Periodicals LLC. on behalf of Society for Ecological Restoration.We are particularly thankful to experts participating in the Delphi process for their generosity in sharing their time and knowledge, and the European Chapter of the Society for Ecological Restoration (SERE), Réseau d'Échanges et de Valorisation en Écologie de la Restauration (REVER), Finnish Board on Ecological Restoration (FBER), Working Group on Ecological Restoration of the Spanish Association for Terrestrial Ecology (ER-AEET), Dutch Knowledge Network for Restoration and Management of Nature (OBN), German Restoration Network (GRN), UK Chartered Institute of Ecology and Environmental Management (CIEEM), Portuguese Network of Ecological Restoration (RPRE), Iberian Center for River Restoration (CIREF), and European Federation of Soil Bioengineering (EFIB) for suggesting candidates to the consulting process. We appreciate the support given by BiodivERsA (project funded under the EU Horizon 2020 ERA-NET COFUND scheme), and the EKLIPSE project (European Union Horizon 2020 grant agreement 690474), and particularly by Juliette C. Young. JCS research is financially supported by the Spanish Ministry of Science, Education and Universities and European Regional Development Funds (FEDER; project COSTERA, RTI2018-095954-B-I00). PMRG research is funded by the Portuguese Foundation for Science and Technology (FCT) through FCT Investigator Program grant number IF/00059/2015, and Centro de Estudos Florestais is supported by FCT grants UID/AGR/00239/2019 and UIDB/00239/2020
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