2,310 research outputs found

    Genetic and phenotypic diversity of autochthonous cider yeasts in a cellar from Asturias

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    This paper analyses yeast diversity and dynamics during the production of Asturian cider. Yeasts were isolated from apple juice and at different stages of fermentation in a cellar in Villaviciosa during two Asturian cider-apple harvests. The species identified by ITS-RFLP corresponded to Hanseniaspora valbyensis, Hanseniaspora uvarum, Metschnikowia pulcherrima, Pichia guilliermondii, Candida parapsilosis, Saccharomyces cerevisiae and Saccharomyces bayanus/Saccharomyces pastorianus/Saccharomyces kudriavzevii/Saccharomyces mikatae. The species C. parapsilosis is reported here for the first time in cider. The analysis of Saccharomyces mtDNA patterns showed great diversity, sequential substitution and the presence of a small number of yeast patterns (up to 8), present in both harvests. Killer (patterns nos. 22' and 47), sensitive (patterns nos. 12, 15, 33 and 61) and neutral phenotypes were found among the S. cerevisiae isolates. The detection of beta-glucosidase activity, with arbutin as the sole carbon source, allowed two S. cerevisiae strains (patterns nos. 3' and 19') to be differentiated by means of this enzymatic activity. Yeast strains producing the killer toxin or with beta-glucosidase activity are reported for the first time in autochthonous cider yeasts

    Climatology of aerosol optical properties and black carbon mass absorption cross section at a remote high-altitude site in the western Mediterranean Basin

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    Aerosol light scattering (&sigma;<sub>sp</sub>), backscattering (&sigma;<sub>bsp</sub>) and absorption (&sigma;<sub>ap</sub>) were measured at Montsec (MSC; 42°3' N, 0°44' E, 1570 m a.s.l.), a remote high-altitude site in the western Mediterranean Basin. Mean (±SD) &sigma;<sub>sp</sub>, &sigma;<sub>bsp</sub> and &sigma;<sub>ap</sub> were 18.9 ± 20.8, 2.6 ± 2.8 and 1.5 ± 1.4 Mm<sup>−1</sup>, respectively at 635 nm during the period under study (June 2011–June 2013). Mean values of single-scattering albedo (SSA, 635 nm), the scattering Ångström exponent (SAE, 450–635 nm), backscatter-to-scatter ratio (<i>B</i> / <i>S</i>, 635 nm), asymmetry parameter (<i>g</i>, 635 nm), black carbon mass absorption cross section (MAC, 637 nm) and PM<sub>2.5</sub> mass scattering cross section (MSCS, 635 nm) were 0.92 ± 0.03, 1.56 ± 0.88, 0.16 ± 0.09, 0.53 ± 0.16, 10.9 ± 3.5 m<sup>2</sup> g<sup>−1</sup> and 2.5 ± 1.3 m<sup>2</sup> g<sup>−1</sup>, respectively. The scattering measurements performed at MSC were in the medium/upper range of values reported by Andrews et al. (2011) for other mountaintop sites in Europe due to the frequent regional recirculation scenarios (SREG) and Saharan dust episodes (NAF) occurring mostly in spring/summer and causing the presence of polluted layers at the MSC altitude. However, the development of upslope winds and the possible presence of planetary boundary layer air at MSC altitude in summer may also have contributed to the high scattering observed. Under these summer conditions no clear diurnal cycles were observed for the measured extensive aerosol optical properties (&sigma;<sub>sp</sub>, &sigma;<sub>bsp</sub> and &sigma;<sub>ap</sub>). Conversely, low &sigma;<sub>sp</sub> and &sigma;<sub>ap</sub> at MSC were measured during Atlantic advections (AA) and winter regional anticyclonic episodes (WREG) typically observed during the cold season in the western Mediterranean. Therefore, a season-dependent decrease in the magnitude of aerosol extensive properties was observed when MSC was in the free troposphere, with the highest free-troposphere vs. all-data difference observed in winter and the lowest in spring/summer. The location of MSC station allowed for a reliable characterization of aerosols as a function of the main synoptic meteorological patterns. The SAE was the lowest during NAF and showed an inverse correlation with the outbreak intensity, indicating a progressive shift toward larger particles. Moreover, the strength of NAF episodes in the region led to a slope of the scattering vs. absorption relationship among the lowest reported for other mountaintop sites worldwide, indicating that MSC was dominated by dust aerosols at high aerosol loading. As a consequence, SSA showed a nearly monotonic increase with increasing particle concentration and scattering. The SAE was the highest during SREG, indicating the presence of polluted layers dominated by smaller particles. Correspondingly, the asymmetry parameter was lower under SREG compared with NAF. The MAC and MSCS were significantly higher during NAF and SREG compared to AA and WREG, indicating an increase of absorption and scattering efficiencies associated with the summer polluted scenarios. The optical measurements performed at the MSC remote site were compared with those simultaneously performed at a regional background station in the western Mediterranean Basin located at around 700 m a.s.l. upstream of the MSC station

    Effect of Class F Fly Ash on Fine Sand Compaction through Soil Stabilization

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    This paper presents the results of an experimental investigation carried out to evaluate the effect of fly ash (FA) on fine sand compaction and its suitability as a material for embankments. The literature review demonstrates the lack of research on stabilization of sandy material using FA. The study is concerned with the role of FA content in stabilized soil physical characteristics. The main aim of this paper is to determine the optimum quantity of FA content for stabilization of this type of soil. This is achieved through particle size distribution and compaction (standard proctor) tests. The sand was stabilized with three proportions of FA (5%, 10% and 15%) and constant cement content of 3% was used as an activator. For better comparison, the sand was also stabilized by 3% cement only so that the effect of FA could be observed more clearly. The results were in line with the literature for other types of soil, i.e. as the % of FA increases, reduction in maximum dry density and higher optimum moisture content were observed

    Variability of aerosol optical properties in the Western Mediterranean Basin

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    Aerosol light scattering, absorption and particulate matter (PM) concentrations were measured at Montseny, a regional background site in the Western Mediterranean Basin (WMB) which is part of the European Supersite for Atmospheric Aerosol Research (EUSAAR). Off line analyses of 24 h PM filters collected with Hi-Vol instruments were performed for the determination of the main chemical components of PM. Mean scattering and hemispheric backscattering coefficients (@ 635 nm) were 26.6±23.2 Mm&lt;sup&gt;−1&lt;/sup&gt; and 4.3±2.7 Mm&lt;sup&gt;−1&lt;/sup&gt;, respectively and the mean aerosol absorption coefficient (@ 637 nm) was 2.8±2.2 Mm&lt;sup&gt;−1&lt;/sup&gt;. Mean values of Single Scattering Albedo (SSA) and Ångström exponent (&lt;i&gt;å&lt;/i&gt;) (calculated from 450 nm to 635 nm) at MSY were 0.90±0.05 and 1.3±0.5 respectively. A clear relationship was observed between the PM&lt;sub&gt;1&lt;/sub&gt;/PM&lt;sub&gt;10&lt;/sub&gt; and PM&lt;sub&gt;2.5&lt;/sub&gt;/PM&lt;sub&gt;10&lt;/sub&gt; ratios as a function of the calculated Ångström exponents. Mass scattering cross sections (MSC) for fine mass and sulfate at 635 nm were 2.8±0.5 m&lt;sup&gt;2&lt;/sup&gt; g&lt;sup&gt;−1&lt;/sup&gt; and 11.8±2.2 m&lt;sup&gt;2&lt;/sup&gt; g&lt;sup&gt;−1&lt;/sup&gt;, respectively, while the mean aerosol absorption cross section (MAC) was 10.4±2.0 m&lt;sup&gt;2&lt;/sup&gt; g&lt;sup&gt;−1&lt;/sup&gt;. The variability in aerosol optical properties in the WMB were largely explained by the origin and ageing of air masses over the measurement site. The MAC values appear dependent of particles aging: similar to the expected absorption cross-section for fresh emissions under Atlantic Advection episodes and higher under aerosol pollution episodes. The analysis of the Ångström exponent as a function of the origin the air masses revealed that polluted winter anticyclonic conditions and summer recirculation scenarios typical of the WMB led to an increase of fine particles in the atmosphere (&lt;i&gt;å&lt;/i&gt; = 1.5±0.1) while the aerosol optical properties under Atlantic Advection episodes and Saharan dust outbreaks were clearly dominated by coarser particles (&lt;i&gt;å&lt;/i&gt; = 1.0±0.4). The sea breeze played an important role in transporting pollutants from the developed WMB coastlines towards inland rural areas, changing the optical properties of aerosols. Aerosol scattering and backscattering coefficients increased by around 40 % in the afternoon when the sea breeze was fully developed while the absorption coefficient increased by more than 100 % as a consequence of the increase in the equivalent black carbon concentration (EBC) observed at MSY under sea breeze circulation

    Monitoring the impact of desert dust outbreaks for air quality for health studies

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    We review the major features of desert dust outbreaks that are relevant to the assessment of dust impacts upon human health. Our ultimate goal is to provide scientific guidance for the acquisition of relevant population exposure information for epidemiological studies tackling the short and long term health effects of desert dust. We first describe the source regions and the typical levels of dust particles in regions close and far away from the source areas, along with their size, composition, and bio-aerosol load. We then describe the processes by which dust may become mixed with anthropogenic particulate matter (PM) and/or alter its load in receptor areas. Short term health effects are found during desert dust episodes in different regions of the world, but in a number of cases the results differ when it comes to associate the effects to the bulk PM, the desert dust-PM, or non-desert dust-PM. These differences are likely due to the different monitoring strategies applied in the epidemiological studies, and to the differences on atmospheric and emission (natural and anthropogenic) patterns of desert dust around the world. We finally propose methods to allow the discrimination of health effects by PM fraction during dust outbreaks, and a strategy to implement desert dust alert and monitoring systems for health studies and air quality management.The systematic review was funded by WHO with as part of a Grant Agreement with Ministry of Foreign Affairs, Norway. Thanks are also given to the Spanish Ministry for the Ecological Transition for long term support in the last 2 decades to our projects on African dust effects on air quality over Spain; to the Spanish Ministry of Science, Innovation and Universities and FEDER Funds for the HOUSE project (CGL2016-78594-R), and to the Generalitat de Catalunya (AGAUR 2017 SGR41). Carlos Pérez García-Pando acknowledges long-term support from the AXA Research Fund, as well as the support received through the Ramón y Cajal program (grant RYC-2015-18690) of the Spanish Ministry of Science, Innovation and Universities.Peer ReviewedPostprint (published version

    Two RNA-binding motifs in eIF3 direct HCV IRES-dependent translation.

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    The initiation of protein synthesis plays an essential regulatory role in human biology. At the center of the initiation pathway, the 13-subunit eukaryotic translation initiation factor 3 (eIF3) controls access of other initiation factors and mRNA to the ribosome by unknown mechanisms. Using electron microscopy (EM), bioinformatics and biochemical experiments, we identify two highly conserved RNA-binding motifs in eIF3 that direct translation initiation from the hepatitis C virus internal ribosome entry site (HCV IRES) RNA. Mutations in the RNA-binding motif of subunit eIF3a weaken eIF3 binding to the HCV IRES and the 40S ribosomal subunit, thereby suppressing eIF2-dependent recognition of the start codon. Mutations in the eIF3c RNA-binding motif also reduce 40S ribosomal subunit binding to eIF3, and inhibit eIF5B-dependent steps downstream of start codon recognition. These results provide the first connection between the structure of the central translation initiation factor eIF3 and recognition of the HCV genomic RNA start codon, molecular interactions that likely extend to the human transcriptome

    Stabilization process in Saccharomyces intra- and interspecific hybrids in fermentative conditions

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    We evaluated the genetic stabilization of artificial intra-(Saccharomyces cerevisiae) and interspecific (S. cerevisiae &times; S. kudriavzevii) hybrids under wine fermentative conditions. Large-scale transitions in genome size and genome reorganizations were observed during this process. Interspecific hybrids seem to need fewer generations to reach genetic stability than intraspecific hybrids. The largest number of molecular patterns recovered among the derived clones was observed for intraspecific hybrids, particularly for those obtained by rare-mating. Molecular marker analyses revealed that unstable clones could change during the industrial process to obtain active dry yeast. When no changes in molecular markers and ploidy were observed after this process, no changes in genetic composition were confirmed by comparative genome hybridization, considering the clone as a stable hybrid. According to our results, under these conditions, fermentation steps 3 and 5 (30&ndash;50 generations) would suffice to obtain genetically stable interspecific and intraspecific hybrids, respectively. [Int Microbiol 2014; 17(4):213-224]Keywords: Saccharomyces cerevisiae &middot; Saccharomyces kudriavzevii &middot; rare-mating in yeast &middot; molecular markers &middot; DNA content evaluation &middot; stabilization of genome

    Mineralogía de los materiales detríticos de la Fm. Escucha (Albiense inferior) en el distrito minero de Teruel (sector Suroriental de la Cordillera Ibérica)

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    The present study focuses on the determination of the source areas of the Escucha Fm. (Albian) sediments in the Teruel Mining District (NE Spain). To this en4 we have carried out a detailed study of the heavy mineral fraction of the sandstone beds from this sedimentary unit at three stratigraphic successions at the Ariño-Oliete and Utrillas subbasins. The minerals found in the stratigraphic successions studied are in low proportions and a few mineral phases are present. Quartz is the dominant phase in the light mineral association, whereas potassium feldspars and plagioclase are in trace amounts. The opaque heavy minerals are hematite and goethite with minor amounts of pyrite. Finally, the transparent heavy minerals may be divided into the three following major associations: a) turmaline, zircon and rutile (resistant minerals); b) kyanite, staurolite and almandine (metamorphic association); and c) metamorphic mineral association from the Ctrillas sub-basin, characterised by very low heavy mineral proportions, and by the absence of one or various mineral phases from the association b. The flow directions from paleochannels and the absence of metarnorphic minerals in the sandstone levels of the upper unit of the Escucha Fm at the northern areas point to the "Platuforma del Ebro" as a possihle source area The minerals with this origin, with variable morphoscopy, could proceed from sedimentary recycling The metamorphic assemblage found in the southern areas may proceed from the "Macizo Castellano", where gneiss and mica-schists are present. It is not possible to precisse exactly the age of the source areas of the detrital sediments of the Escucha Fm This is due to the fact that these may have been different through the basin evolution, and also to the evidence of recycling processes The middle and lower units of the Escucha Fm at Ariño and Oliete, where the workable coa1 seams are present, show a metamorphic assemblage which demonstrate the Paleozoic age of the source lands Consequently, the Triassic units could also supply detrital minerals to the delta system of the Escucha Fm. These results are consistent with the hypothesis of the Triassic origin of the sulphur enrichment of the coals from the Ariño-Oliete area The recycling of detrital sediments from the Escucha Fm or a different source lana could account for the proteciion of the Utrillas sub-basin against the Triassic sulphate supply, and consequently for the lower sulphur content of the coals from this area.

    Element behaviour during combustion in coal-fired Orhaneli power plant, Bursa-Turkey

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    This study focuses on element behaviour during combustion in the Orhaneli thermal power plant (a 210 MW unit, Bursa-Turkey). A total of 51 samples, feed coals (FCs), fly ashes (FAs) and bottom ashes (BAs), which were systematically collected over an eight-week period, have been analysed for major, minor and trace elements (Al, Ca, Fe, K, Mg, Na, S, As, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Ga, Ge, Hf, Hg, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Th, Ti, Tl, U, V, W, Y, Zn, Zr and REEs). This study shows that FCs on an airdried basis have high moisture (av. 9%), high volatile matter (av. 33%), very high ash yield (av. 53%), relatively high sulfur content (av. 2.14%) and low gross calorific value (av. 1775 kcal/kg). Proximate analyses of combustion residues imply that BAs have higher contents of unburned carbonaceous matter than FAs. Mean values of trace element concentrations in FCs fall within the ranges of most world coals, except for Cr, Cs, Ni and U which occur in concentrations slightly higher than those determined for most of world coals. Some elements such as S, Hg, As, B, Bi, Cd, Cs, Ge, K, Pb, Rb, Sb, Se, Sn, Tl, and Zn are indicating enrichments in FAs. The remaining elements investigated in this study have no clear segregation between FAs and BAs. The mass balance calculations point to Ca content of feed coal controlling the partitioning of elements in this power plant, producing a high removal efficiency for highly volatile elements such as Hg, B and Se, and a high retention of As, Bi, Cd, Cs, Ge, Pb, Rb, Sb, Sn, Tl and Zn in FAs. However, the high enrichment in trace elements of FAs can increase the hazardous potential of this coal by-product

    Cord blood Lin(-)CD45(-) embryonic-like stem cells are a heterogeneous population that lack self-renewal capacity.

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Human umbilical cord blood (hUCB) has been proposed to contain not only haematopoietic stem cells, but also a rare pluripotent embryonic-like stem cell (ELSc) population that is negative for hematopoietic markers (Lin(-)CD45(-)) and expresses markers typical of pluripotent cells. The aim of this work was to isolate, characterise and expand this ELSc fraction from hUCB, as it may provide a valuable cell source for regenerative medicine applications. We found that we could indeed isolate a Lin(-)CD45(-) population of small cells (3-10 µm diameter) with a high nucleus to cytoplasm ratio that expressed the stem cell markers CD34 and CXCR4. However, in contrast to some previous reports, this fraction was not positive for CD133. Furthermore, although these cells expressed transcripts typical of pluripotent cells, such as SOX2, OCT3/4, and NANOG, they were not able to proliferate in any of the culture media known to support stem cell growth that we tested. Further analysis of the Lin(-)CD45(-) population by flow cytometry showed the presence of a Lin(-)CD45(-)Nestin(+) population that were also positive for CD34 (20%) but negative for CXCR4. These data suggest that the Lin(-)CD45(-) stem cell fraction present in the cord blood represents a small heterogeneous population with phenotypic characteristics of stem cells, including a Lin(-)CD45(-)Nestin(+) population not previously described. This study also suggests that heterogeneity within the Lin(-)CD45(-) cell fraction is the likely explanation for differences in the hUCB cell populations described by different groups that were isolated using different methods. These populations have been widely called "embryonic-like stem cell" on the basis of their phenotypical similarity to embryonic stem cells. However, the fact they do not seem to be able to self-renew casts some doubt on their identity, and warns against defining them as "embryonic-like stem cell" at this stage.Anthony Nolan and the Great Ormond Street Hospital Charity for financial support. Cesar Alvarez-Gonzalez is a fellowship from Consejo Nacional de Ciencia y Tecnologia (CONACyT) and Instituto Jaliscience de la Juventud (IJJ); Mexico
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