2,282 research outputs found

    Analyses of Genetic Diversity in the Endangered “Berrenda” Spanish Cattle Breeds Using Pedigree Data

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    Pedigree analyses of two endangered cattle breeds were performed in order to study the structure and the genetic variability in their populations. Pedigree data were analyzed from 12,057 individuals belonging to the “Berrenda en Negro” cattle breed (BN) and 20,389 individuals belonging to the “Berrenda en Colorado” cattle breed (BC) that were born between 1983 and 2020. BN and BC reference populations (RP) were set up by 2300 and 3988 animals, respectively. The generation interval in BN and BC reference populations was equal to 6.50 and 6.92 years, respectively. The pedigree completeness level was 82.76% in BN and 79.57% in BC. The inbreeding rates were 4.5% in BN and 3.4% in BC, respectively. The relationship among animals when they were born in different herds was 1.8% in BN and 5% in BC; these values increased to 8.5% and 7.7%, respectively when comparing animals that were born in the same herd. The effective number of founding herds was 23.9 in BN and 60.9 in BC. Number of ancestors needed to explain 50% of genes pool in the whole population was 50 and 101, in BN and in BC, respectively. The effective population size based on co-ancestries was 92.28 in BN and 169.92 in BC. The genetic variability has been maintained in both populations over time and the results of this study suggest that measures to promote the conservation of the genetic variability in these two breeds would go through for the exchange of breeding animals among farms and for monitoring the genetic contributions before implementing any selective action

    Energy impact and CO2 emissions of a building with different façade solutions

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    [EN]This work uses a simplified life cycle analysis (LCA) methodology to explore the impact reduction potential in the design phase in terms of primary energy and greenhouse gas emissions for a given building using several façade solutions. This is achieved through a review of several design criteria (wall characteristics, insulation level, reposition rate and component durability) and their combinations, and analizing how they relate to the selected impacts for the production and use stages in the building life cycle. Results show that both emissions and energy embedded into the building materials or the building process are of great relevance and impact of emissions is comparable to those due to the use stage. This work concludes that, for a given building, a significant impact reduction on the selected impact indicators can be achieved by a careful selection of building solutions and durability strategies (through maintenance or refurbishment) in the design phase.[ES]El artículo emplea una simplificación de la metodología del análisis de ciclo de vida (ACV) para explorar en fase de proyecto el potencial de reducción de impactos, en términos de energía primaria y emisiones de gases de efecto invernadero, para diferentes soluciones de fachada y estrategias de durabilidad. Se evalúan a nivel de edificio varias alternativas de diseño de una fachada tipo (configuración del muro, aislamiento, frecuencia de reposición y durabilidad) y se analiza su repercusión en los impactos seleccionados para las etapas de producción y uso del edificio. Se concluye la importancia de la energía y emisiones incorporadas a los materiales y procesos de construcción en los impactos totales, siendo las emisiones en esas fases comparables a las de la fase de uso. Se concluye la posibilidad de reducir significativamente los impactos mediante una selección cuidadosa de los criterios de diseño y estrategias apropiadas de durabilidad, mantenimiento y rehabilitación.Peer reviewe

    Nutrient limitation can explain a rapid transition to synchrony in an upwelling-driven diatom community

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    Identifying the mechanisms controlling the temporal dynamics of ecological communities is key to understand their vulnerability to natural and anthropogenic impacts and to identify early warnings of critical transitions. At community level, inter-specific synchrony is an important indicator of ecosystem stability and variation in function. Using wavelet analysis on time-series of abundance of 12 dominant diatom species, sampled monthly (1994-2009) in a coastal upwelling embayment at the northern limit of the Canary Current Upwelling System, we find a sudden onset of synchrony between 1998 and 2002, concomitant with an increase in the amplitude of the upwelling index at different temporal scales. To better understand the underlying mechanism that could generate this sudden onset of synchrony among competitors, we analyzed a general model of competition between two species for two essential nutrients (e.g., nitrogen and silicate). We incorporate environmental variation by varying the concentration of one of the essential nutrients entering the system. Increase in the amplitude of environmental variation always leads to greater synchrony among competitors. This occurs because the system shifts from a state in which species are limited by different nutrients to one where species are often limited by the same nutrient. We show that the transition from asynchronous to synchronous dynamics can occur suddenly as the amplitude of environmental variation increases. While it is not possible to rule out alternative mechanisms, our model demonstrates that sudden changes in the extent of synchronization should be a common feature when species compete for essential nutrients in variable environments.En prensa3,38

    Fabrication of strong magnetic micron-sized supraparticles with anisotropic magnetic properties for magnetorheology

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    Dr Tavacoli is acknowledged for useful discussions. This work was supported by MICINN PID2019-104883GB-I00 project (Spain), Junta de Andalucı´a P18-FR-2465 project and European Regional Development Fund (ERDF). J. R. M. acknowledges FPU14/01576 fellowship. E. C.-G. acknowledges financial support by CONACYT (Ref. #232347).We propose three different techniques to synthesize anisotropic magnetic supraparticles for their incorporation in the formulation of magnetorheological fluids with novel potential applications. The techniques include microtransfer molding, electrodeposition and microfluidic flow-focusing devices. Although the yield of these methods is not large, with their use, it is possible to synthesize supraparticles with anisotropy in both their magnetic content and shape. The magnetorheological characteristics (yield stress) of the resulting field-induced structures were computed using finite element method simulations and demonstrated to be strongly dependent on the microstructural anisotropy of the supraparticles. In anisotropic particles, the simulated yield stress is always larger than that of the isotropic ones consisting of magnetically homogeneous spherical particles.MICINN PID2019-104883GB-I00 project (Spain)Junta de Andalucía P18-FR-2465 projectEuropean Regional Development Fund (ERDF)FPU14/01576CONACYT (Ref. #232347

    Low-Cost Prototype to Automate the 3D Digitization of Pieces: An Application Example and Comparison

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    This work is aimed at describing the design of a mechanical and programmable 3D capturing system to be used by either 3D scanner or DSLR camera through photogrammetry. Both methods are widely used in diverse areas, from engineering, architecture or archaeology, up to the field of medicine; but they also entail certain disadvantages, such as the high costs of certain equipment, such as scanners with some precision, and the need to resort to specialized operatives, among others. The purpose of this design is to create a robust, precise and cost-effective system that improves the limitations of the present equipment on the market, such as robotic arms or rotary tables. For this reason, a preliminary study has been conducted to analyse the needs of improvement, later, we have focused on the 3D design and prototyping. For its construction, there have been used the FDM additive technology and structural components that are easy to find in the market. With regards to electronic components, basic electronics and Arduino-based 3D printers firmware have been selected. For system testing, the capture equipment consists of a Spider Artec 3D Scanner and a Nikon 5100 SLR Camera. Finally, 3D models have been developed by comparing the 3D meshes obtained by the two methods, obtaining satisfactory results

    Evaluación de un yogur con características simbióticas y su efecto sobre la vida útil del producto.

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    En el desarrollo de este trabajo, se utilizo para la elaboración del yogurt simbiótico los microorganismos Bifidobacterium animalis ssp. Lactis, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus y como carbohidrato la oligofructosa, los cuales cumplen las funciones de probiótico y prebiótico respectivamente. El producto desarrollado se elaboró primero a escala de laboratorio y posteriormente a escala industrial, realizando pruebas microbiológicas y fisicoquímicas según lo definido en el Decreto 616 del 2006 del Ministerio de la protección social y la Resolución 02310 de 1986 del Ministerio de salud. La cuantificación de la oligofructosa se realizó por la técnica de azúcares reductores y el recuento en placa profunda para la cuantificación de las bacterias lácticas utilizando el medio RMS.. La caducidad del producto fue evaluada colocando el producto a temperaturas de 5, 15 y 25ºC utilizando el modelo de Arrhenius, analizando constantemente el porcentaje de ácido láctico producido. Paralelamente se realizó la evaluación sensorial mediante la prueba de aceptabilidad del producto (yogurt). Se logró desarrollar un yogurt simbiótico estable, cuyas características se mantuvieron durante el periodo de almacenamiento al que fue sometido; En conclusión la vida útil del yogurt simbiótico evaluado fue de 31 días tiempo considerado estable para su comercialización, donde conservará sus características simbióticas

    Spatial and temporal patterns of sea surface chlorophyll concentration and environmental forcing in the southern European Atlantic

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    Phytoplankton biomass dynamic integrates information about the characteristics of the pelagic ecosystem. Temporal and spatial patterns respond to physical processes. Also, phytoplankton abundance and its temporal dynamic largely determine the structure and dynamics of the food web. The southern European Atlantic (48 ºN – 36 ºS) presents differences in continental margin orientation, upwelling intensity, river runoff, a semi-enclosed oceanic domain (Bay of Biscay), and open oceanic waters to the west. Sea surface chlorophyll concentration (SSChl) monthly averages (from satellites) from 1998 to 2012 were analysed at 4x4 km resolution by Empirical Orthogonal Functions. The study area was regionalized according to rotated EOFs and temporal modes were used to resume the SSChl temporal variability in each region. The environmental forcing of temporal modes was analysed against environmental variables by means of Canonical Correspondence Analysis. More than 50% of the variability in oceanic regions was captured by the seasonal signal, with differences in the timing of the spring bloom and with the shape of the seasonal signal related with the latitudinal gradient and the ‘stagnation effect’ of the Bay of Biscay. In French and western Iberian shelves seasonality represented 50%. The difference between shelf and oceanic regions was due to mesoscale processes in shelf areas; i.e. river runoff in the French shelf and coastal upwelling in the western Iberian shelf. Shelf mesoscale processes impose short frequency variability on to the seasonal cycle and increase SSChl levels. The influence that these patterns of spatial and temporal dynamics have on the structure and dynamics of the rest of the food web can be perceived on the spatial patterns of fisheries catches

    Data mining to assess organizational transparency across technology processes: an approach from IT governance and knowledge management

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    Information quality and organizational transparency are relevant issues for corporate governance and sustainability of companies, as they contribute to reducing information asymmetry, decreasing risks, and improving the conduct of decision-makers, ensuring an ethical standard of organizational control. This work uses the COBIT framework of IT governance, knowledge management, and machine learning techniques to evaluate organizational transparency considering the maturity levels of technology processes applied in 285 companies of southern Brazil. Data mining techniques have been methodologically applied to analyze the 37 processes in four different domains: Planning and organization, acquisition and implementation, delivery and support, and monitoring. Four learning techniques for knowledge discovery have been used to build a computational model that allowed us to evaluate the organizational transparency level. The results evidence the importance of IT performance monitoring and assessment, and internal control processes in enabling organizations to improve their levels of transparency. These processes depend directly on the establishment of IT strategic plans and quality management, as well as IT risk and project management, therefore an improvement in the maturity of these processes implies an increase in the levels of organizational transparency and their reputational, financial, and accountability impact
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