1,821 research outputs found

    Presencia de Vulpes praeglacialis (Kormos, 1932) en el yacimiento pleistoceno de la Sierra de Quibas (Abanilla, Murcia)

    Get PDF
    En el presente trabajo se describen los primeros restos de un cánido en el Pleistoceno inferior de la Sierra de Quibas (Abanilla, Murcia), ampliándose la escasa representación de carnívoros en el yacimiento. Son atribuidos a la especie Vulpes praeglacialis, zorro típico del Pleistoceno inferior, en función de su reducido tamaño y del escaso desarrollo del dentículo posterior del p3.We describe the first remains of Canidae from the Lower Pleistocene karstic locality of Quibas (Abanillas, Murcia) that increasing the representation of carnivores in this site. These fossils are identified as Vulpes praeglacialis, the typical Lower Pleistocene fox. This assignment is based on their small size and the poorly developed posterior cuspid of the p/[email protected]

    Capra alba Moyà-Solà, 1987 del Pleistoceno Inferior de la Sierra de Quibas (Albanilla, Murcia, España)

    Get PDF
    A finales de la década de los 90 se realizó el primer estudio paleontológico del yacimiento de la Sierra de Quibas (Montoya et al., 1999) en el que se describieron más de 60 taxones de vertebrados. Uno de ellos fue el de un caprino asignado como Capra sp. aff Capra alba. Las últimas campañas de excavación han librado nuevos restos de este taxón, lo que ha permitido poder estudiarlo con mayor profundidad y asignarlo a Capra alba. Esta atribución se basa en la comparación morfológica y métrica de los cráneos, núcleos óseos, dentición y metápodos con los ejemplares de C. alba de Venta Micena (Orce, Granada).The first palaeontological study of the locality of Quibas dates from the end of the 1990ties (Montoya et al., 1999), describing over 60 vertebrate taxa. One of these was a caprine assigned to Capra sp. aff. Capra alba. Recent excavations yielded new remains of this taxon, which permits a more profound study of its affinities and an assignation to Capra alba, without reservation. This assignation is based on the morphological and metrical comparison of the skulls, horn cores, dentition and metapodials from Quibas with those of Capra alba from Venta Micena (Orce Granada)[email protected]

    Benchwood: Una experiencia de benchmarking para la mejora continua

    Get PDF
    [ESP] Esta ponencia presenta el trabajo realizado en el proyecto de investigación denominado Benchwood desarrollado por el Grupo de Ingeniería de Organización (GIO) de la Universidad de Vigo, al cual pertenecen los autores, en colaboración con el Clúster de la Madera de Galicia (CMA) y que se enmarca en el Plan Estratégico Operativo de la Madera 2008-2011 de éste. El Clúster de la Madera de Galicia (CMA) nació en 2001 con la finalidad de lograr la unión, cooperación e integración del conjunto de empresas y agentes de la cadena de la madera de la Comunidad Autónoma de Galicia (España), buscando alcanzar una mayor nivel de competitividad en todo el sector, establecer las bases de futuras actuaciones conjuntas, constituir un foro de debate y acción, en el fomento de la cultura maderera gallega y, en general, para la defensa de todos sus intereses. El Clúster reúne actualmente a 60 empresas de la comunidad autónoma gallega, pertenecientes a distintos subsectores de la cadena de la madera: forestal, aserradero, chapa y tablero, pasta y papel, carpintería y mobiliario, adhesivos y barnices y servicios. El volumen de negocio que generan las empresas asociadas al Clúster supone más de 1.500 millones de euros, lo que representa cerca del 70% del total del sector, y dan empleo directo a más de 11.500 trabajadores

    Biofuels from Diethyl Carbonate and Vegetable Oils for Use in Triple Blends with Diesel Fuel: Effect on Performance and Smoke Emissions of a Diesel Engine

    Get PDF
    The main objective of this work is to contribute to a gradual replacement process of fossil diesel (D) with biofuels composed by diethyl carbonate (DEC) and either sunflower or castor oil, as straight vegetable oils (SVOs). DEC is a very interesting candidate as an oxygenated additive not only because of its low price and renewable nature, but also its favorable fuel properties, such as very low kinematic viscosity, high cetane number, high oxygen content, rich cold flow properties and good miscibility with fossil diesel and vegetable oils. In this work, the more suitable DEC/SVO biofuels are chosen based on kinematic viscosity, according to the European normative. Additionally, the most relevant physical–chemical properties of (bio)fuels such as density, calorific value, cloud point, pour point and cetane number are determined. The influence of DEC on engine performance and exhaust emissions is analyzed by fueling a conventional Diesel engine with the different D/DEC/SVO triple and DEC/SVO double mixtures. The tests results are also compared with commercial diesel. From the results, it is concluded that Diesel engine fueled with the blends studied exhibits an excellent performance in terms of power output, very similar to diesel. Additionally, the use of these blends can remarkably decrease smoke emissions down to 98%, with respect to fossil diesel. The addition of DEC shows a significant improvement in cold flow properties of fuel mixtures in the exchange of a slightly higher brake specific fuel consumption (BSFC) than diesel. Interestingly, the pure biofuels composed by DEC and SVO allow for a suitable engine operation and achieve the lowest emissions, which means these blends can be successfully employed in current engines without adding fossil diesel, i.e., their use entail a 100% renewability

    Evaluation of Dimethyl Carbonate as Alternative Biofuel. Performance and Smoke Emissions of a Diesel Engine Fueled with Diesel/Dimethyl Carbonate/Straight Vegetable Oil Triple Blends

    Get PDF
    Dimethyl carbonate (DMC) is an interesting blending component for diesel fuel (D) owing to the high oxygen content (53 wt.%) and the absence of C–C bonds in its structure. Moreover, DMC can be produced from CO2 and methanol, which provides a renewable way to reduce anthropogenic CO2. This research has been addressed to assess the use of DMC as a solvent of sunflower oil (SO) and castor oil (CO), with the purpose of obtaining biofuels that can replace fossil diesel as much as possible. The blending of DMC with straight vegetable oils (SVOs) reduces their high viscosity, allowing their usage as drop-in biofuels without chemical treatments. Based on viscosity requirements of European Standard EN 590, the optimal DMC/SVO double blends have been tested as direct biofuels by themselves or mixed with fossil diesel in D/DMC/SVO triple blends. Relevant physico-chemical properties of fuels have been analyzed. Engine parameters such as power output, brake-specific fuel consumption (BSFC) and soot emissions have been studied to determine the effect of new biofuels on efficiency of a diesel engine. An outstanding engine efficiency is shown by the studied D/DMC/SVO triple blends, either with SO or CO as an SVO. The low calorific value of DMC is the main reason for reduction in power and BSFC, as the amount of diesel in the triple blends is reduced. Experimental results demonstrate that the use of these biofuels allows the replacement of up to 40% of fossil diesel, without compromising the power and BSFC of the engine, and accomplishing optimal cold flow properties and a marked drop in exhaust emissions

    Outlook for Direct Use of Sunflower and Castor Oils as Biofuels in Compression Ignition Diesel Engines, Being Part of Diesel/Ethyl Acetate/Straight Vegetable Oil Triple Blends

    Get PDF
    Today, biofuels are indispensable in the implementation of fossil fuels replacement processes. This study evaluates ethyl acetate (EA) as a solvent of two straight vegetable oils (SVOs), castor oil (CO), and sunflower oil (SO), in order to obtain EA/SVO double blends that can be used directly as biofuels, or along with fossil diesel (D), in the current compression-ignition (C.I.) engines. The interest of EA as oxygenated additive lies not only in its low price and renewable character, but also in its very attractive properties such as low kinematic viscosity, reasonable energy density, high oxygen content, and rich cold flow properties. Revelant fuel properties of EA/SVO double and D/EA/SVO triple blends have been object of study including kinematic viscosity, pour point (PP), cloud point (CP), calorific value (CV), and cetane number (CN). The suitability of using these blends as fuels has been tested by running them on a diesel engine electric generator, analyzing their effect on engine power output, fuel consumption, and smoke emissions. Results obtained indicate that the D/EA/SO and D/EA/CO triple blends, composed by up to 24% and 36% EA, respectively, allow a fossil diesel substitution up to 60–80% providing power values very similar to conventional diesel.In addition, in exchange of a slight fuel consumption, a very notable lessening in the emission of pollutants as well as a better behavior at low temperatures, as compared to diesel, are achieved

    Acetone Prospect as an Additive to Allow the Use of Castor and Sunflower Oils as Drop-In Biofuels in Diesel/Acetone/Vegetable Oil Triple Blends for Application in Diesel Engines

    Get PDF
    The present paper investigates the feasibility of using acetone (ACE) in triple blends with fossil diesel (D) and straight vegetable oils (SVOs) as alternative fuel for diesel engines. In this respect, ACE is selected as an oxygenated additivedue to its favorable propertiesto be mixed with vegetable oils and fossil diesel. In fact, the very low kinematic viscosity allows reduces the high viscosity of SVOs. ACE’s oxygen content, low autoignition temperature, and very low cloud point and pour point values highlight its possibilities as an additive in D/ACE/SVO triple blends. Moreover, ACE can be produced through a renewable biotechnological process, an acetone–butanol–ethanol (ABE) fermentation from cellulosic biomass. The SVOs tested were castor oil (CO), which is not suitable for human consumption, and sunflower oil (SO), used as a standard reference for waste cooking oil. The viscosity measurement of the ACE/SVO double blend was considered crucial to choose the optimum proportion, which better fulfilled the specifications established by European standard EN 590. Moreover, some of the most significant physicochemical properties of D/ACE/SVO triple blends, such as kinematic viscosity, cloud point, pour point, and calorific value, were determined to assess their suitability as fuels. The blends were evaluated in a conventional diesel generator through the study of the following parameters: engine power, smoke emissions, and fuel consumption. Despite the low calorific value of ACE limits its ratio in the mixtures due to engine knocking problems, the experimental results reveal an excellent performance for the blends containing up to 16-18% of ACE and 22-24% of SVO. These blends produce similar engine power as to fossil diesel, but with slightly higher fuel consumption. Considerable reductions in emissions of air pollutants, as well as excellent cold flow properties are also obtained with these triple blends. In summary, the use of these biofuels could achieve a substitution of fossil diesel up to 40%, independently on the SVO employed

    Presence of Mammuthus sp. from Caravaca (Murcia)

    Get PDF
    In Rambla del Pizcalejo (Caravaca, Murcia, Spain) new Proboscidea fossil remains were found. In this paper are described all postcranial bones belonging to a 2-4 years old Mammuthus. Stratigraphycal and mollusc data confirm the lacustrine paleoenvironment. The remains shouldn’t have suffered a hard transport; neither should their time of exposure have been long. The date of the remains is not precise due to the lack of chronostratigraphic and biostratigraphic data. It is only the assignment of the remains to the genus Mammuthus that allows to surmise a period about Plio-Pleistocen

    Combined Single-Cell Functional and Gene Expression Analysis Resolves Heterogeneity within Stem Cell Populations.

    Get PDF
    Heterogeneity within the self-renewal durability of adult hematopoietic stem cells (HSCs) challenges our understanding of the molecular framework underlying HSC function. Gene expression studies have been hampered by the presence of multiple HSC subtypes and contaminating non-HSCs in bulk HSC populations. To gain deeper insight into the gene expression program of murine HSCs, we combined single-cell functional assays with flow cytometric index sorting and single-cell gene expression assays. Through bioinformatic integration of these datasets, we designed an unbiased sorting strategy that separates non-HSCs away from HSCs, and single-cell transplantation experiments using the enriched population were combined with RNA-seq data to identify key molecules that associate with long-term durable self-renewal, producing a single-cell molecular dataset that is linked to functional stem cell activity. Finally, we demonstrated the broader applicability of this approach for linking key molecules with defined cellular functions in another stem cell system.Work in the author’s laboratory is supported by grants from the Leukaemia and Lymphoma Research, the Medical Research Council, Cancer Research UK, Biotechnology and Biological Sciences Research Council, Leukemia Lymphoma Society, and the National Institute for Health Research Cambridge Biomedical Research Centre and core support grants by the Wellcome Trust to the Cambridge Institute for Medical Research and Wellcome Trust-MRC Cambridge Stem Cell Institute. D.G.K. is the recipient of a Canadian Institutes of Health Research Postdoctoral Fellowship. F.B. and F.J.T. are funded by the European Research Council (starting grant “LatentCauses”). For funding for the open access charge, the core support grant was provided by the Wellcome Trust-MRC Cambridge Stem Cell Institute. We acknowledge the support of the University of Cambridge, Cancer Research UK Institute (core grant C14303/A17197), and Hutchison Whampoa Limited.This is the final published version. It first appeared at http://www.cell.com/cell-stem-cell/abstract/S1934-5909%2815%2900162-9

    Parasites of the Reintroduced Iberian Lynx (Lynx pardinus) and Sympatric Mesocarnivores in Extremadura, Spain.

    Get PDF
    The Iberian lynx (Lynx pardinus) is one of the most endangered felid species in the world. Conservation efforts have increased its population size and distribution and reinforced their genetic diversity through captive breeding and reintroduction programmes. Among several threats that the Iberian lynx faces, infectious and parasitic diseases have underlined effects on the health of their newly reintroduced populations, being essential to identify the primary sources of these agents and assess populations health status. To achieve this, 79 fresh faecal samples from Iberian lynx and sympatric mesocarnivores were collected in the reintroduction area of Extremadura, Spain. Samples were submitted to copromicroscopic analyses to assess parasite diversity, prevalence, and mean intensity of parasite burden. Overall, 19 (24.1%, ±15.1-35.0) samples were positive for at least one enteric parasite species. Parasite diversity and prevalence were higher in the Iberian lynx (43.8%) compared with the others mesocarnivores under study (e.g., the red fox Vulpes vulpes and the Egyptian mongoose Herpestes ichneumon). Ancylostomatidae and Toxocara cati were the most prevalent (15.6%) parasites. Obtained results revealed that Iberian lynx role as predator control might have reduced parasite cross-transmission between this felid and mesocarnivores due to their decreasing abundances. Surveillance programs must include regular monitoring of this endangered felid, comprising mesocarnivores, but also domestic/feral and wild cat communities.This research was funded by the European Union through its LIFE project Life + IBERLINCE (LIFE + 10NAT/ES/570) “Recuperación de la distribución histórica del lince ibérico (Lynx pardinus) en España y Portugal”. R. T. Torres is funded by national funds (OE), through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July. Thanks are due to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020) and CIISA Project UIDB/00276/2020 through national funds.S
    corecore