3,177 research outputs found

    Natural zeolites and white wines from Campania region (Southern Italy): a new contribution for solving some oenological problems

    Get PDF
    The purpose of this research is to provide a new mixture of Campanian zeolitized tuffs for solving two specific problems in the production of white wines: the protein and tartaric stability. In fact, a very frequent cause of turbidity and formation of organic deposits in white wines is the occurrence of thermolabile and thermostable proteins colloidal suspensions which precipitate in time, especially in summertime and during the storage and transport. Normally, to mitigate this risk wine producers use organic and inorganic stabilizers and clarifiers. The best known treatment, recognized also by the International Organisation of Vine and Wine (OIV) foresees the use of bentonite with a montmorillonite content not lower than 80%. The present paper aims at evaluating the use of two high zeolite grade Italian volcanoclastites such as the Neapolitan Yellow Tuff (NYT) and the Yellow Facies of the Campanian Ignimbrite (YFCI), in the treatment of three peculiar white wines of the Campanian region (Southern Italy): Falanghina, Fiano di Avellino and Greco di Tufo. Granulates were produced starting from tuff blocks as provided by quarries. Some grain size fractions have been prepared to investigate the zeolite content (phillipsite + chabazite + analcime) by X-ray diffraction (XRD). A 2-5 mm grain size fraction was chosen for NYT and a 5-10 mm for YFCI. Three Campanian monocultivar white wines were used for the test: the Falanghina 2006 vintage, the Fiano di Avellino DOCG 2007 vintage, and the Greco di Tufo DOCG 2008 vintage. 48 samples with mixture of the zeolitized tuffs, 1 sample with mixture of a synthetic zeolite A and 1 sample with mixture of a commercial sodium activated bentonite were prepared. ICP-OES analysis for the determination of ECEC, Ion Chromatography (IC) analyses for the determination of some major cations and Turbidimetric tests for the definition of the protein stabilization process before and after treatments were also carried out. It was evidenced that high zeolitized tuff/wine ratios enable the protein stabilization whereas a significant decrease of potassium ion after the treatment with a zeolite-rich powder improves the tartaric stability, a serious problem in all the wine productions. The results of these tests refer to a laboratory scale research. A transfer of the experiment to a pilot plant scale is in progress

    Structure and Evolution of Galaxy Clusters: Internal Dynamics of ABCG 209 at z~0.21

    Get PDF
    We study the internal dynamics of the rich galaxy cluster ABGC 209 on the basis of new spectroscopic and photometric data. The distribution in redshift shows that ABCG 209 is a well isolated peak of 112 detected member galaxies at z=0.209, characterised by a high value of the line-of-sight velocity dispersion, sigma_v=1250-1400 Km/s, on the whole observed area (1 Mpc/h from the cluster center), that leads to a virial mass of M=1.6-2.2x10^15 M_sun within the virial radius, assuming the dynamical equilibrium. The presence of a velocity gradient in the velocity field, the elongation in the spatial distribution of the colour-selected likely cluster members, the elongation of the X-ray contour levels in the Chandra image, and the elongation of cD galaxy show that ABCG 209 is characterised by a preferential NW-SE direction. We also find a significant deviation of the velocity distribution from a Gaussian, and relevant evidence of substructure and dynamical segregation. All these facts show that ABCG 209 is a strongly evolving cluster, possibly in an advanced phase of merging.Comment: 26 pages, 14 figures. A&A in pres

    Photometric redshifts for Quasars in multi band Surveys

    Get PDF
    MLPQNA stands for Multi Layer Perceptron with Quasi Newton Algorithm and it is a machine learning method which can be used to cope with regression and classification problems on complex and massive data sets. In this paper we give the formal description of the method and present the results of its application to the evaluation of photometric redshifts for quasars. The data set used for the experiment was obtained by merging four different surveys (SDSS, GALEX, UKIDSS and WISE), thus covering a wide range of wavelengths from the UV to the mid-infrared. The method is able i) to achieve a very high accuracy; ii) to drastically reduce the number of outliers and catastrophic objects; iii) to discriminate among parameters (or features) on the basis of their significance, so that the number of features used for training and analysis can be optimized in order to reduce both the computational demands and the effects of degeneracy. The best experiment, which makes use of a selected combination of parameters drawn from the four surveys, leads, in terms of DeltaZnorm (i.e. (zspec-zphot)/(1+zspec)), to an average of DeltaZnorm = 0.004, a standard deviation sigma = 0.069 and a Median Absolute Deviation MAD = 0.02 over the whole redshift range (i.e. zspec <= 3.6), defined by the 4-survey cross-matched spectroscopic sample. The fraction of catastrophic outliers, i.e. of objects with photo-z deviating more than 2sigma from the spectroscopic value is < 3%, leading to a sigma = 0.035 after their removal, over the same redshift range. The method is made available to the community through the DAMEWARE web application.Comment: 38 pages, Submitted to ApJ in February 2013; Accepted by ApJ in May 201

    Weak Lensing Mass Reconstruction of the Galaxy Cluster Abell 209

    Get PDF
    Weak lensing applied to deep optical images of clusters of galaxies provides a powerful tool to reconstruct the distribution of the gravitating mass associated to these structures. We use the shear signal extracted by an analysis of deep exposures of a region centered around the galaxy cluster Abell 209, at redshift z=0.2, to derive both a map of the projected mass distribution and an estimate of the total mass within a characteristic radius. We use a series of deep archival R-band images from CFHT-12k, covering an area of 0.3 deg^2. We determine the shear of background galaxy images using a new implementation of the modified Kaiser-Squires-Broadhurst pipeline for shear determination, which we has been tested against the ``Shear TEsting Program 1 and 2'' simulations. We use mass aperture statistics to produce maps of the 2 dimensional density distribution, and parametric fits using both Navarro-Frenk-White (NFW) and singular-isothermal-sphere profiles to constrain the total mass. The projected mass distribution shows a pronounced asymmetry, with an elongated structure extending from the SE to the NW. This is in general agreement with the optical distribution previously found by other authors. A similar elongation was previously detected in the X-ray emission map, and in the distribution of galaxy colours. The circular NFW mass profile fit gives a total mass of M_{200} = 7.7^{+4.3}_{-2.7} 10^{14} solar masses inside the virial radius r_{200} = 1.8\pm 0.3 Mpc. The weak lensing profile reinforces the evidence for an elongated structure of Abell 209, as previously suggested by studies of the galaxy distribution and velocities.Comment: accepted by A&A, 15 pages, 11 figure

    Interferon gamma and lipopolysaccharide promote macrophage adherence to basement membrane glycoproteins

    Get PDF
    The ability of thioglycollate (TG)-elicited peritoneal macrophages, a population of recently recruited monocytes, to adhere to the basement membrane glycoproteins laminin and type IV collagen is not a constitutive function of these cells. Adherence can be induced, however, by treatment with IFN-gamma and LPS. In general, IFN-gamma is more potent than LPS in promoting this adherence. Maximal adherence, however, is observed when IFN-gamma (greater than or equal to 5 U/ml) is used together with LPS (2.0 ng/ml). These requirements parallel the conditions needed to obtain tumoricidal activation of TG-elicited macrophages. Adherence to laminin, in the presence of these stimuli, is transient, being maximal at 8 h after their addition and diminishing with longer periods of incubation. In contrast, adherence to type IV collagen does not appear to be transient and IFN-gamma and LPS induce a more prolonged association of macrophages with this substratum

    Regulation of alpha 6 beta 1 integrin laminin receptor function by the cytoplasmic domain of the alpha 6 subunit

    Get PDF
    The alpha 6 beta 1 integrin is expressed on the macrophage surface in an inactive state and requires cellular activation with PMA or cytokines to function as a laminin receptor (Shaw, L. M., J. M. Messier, and A. M. Mercurio. 1990. J. Cell Biol. 110:2167-2174). In the present study, the role of the alpha 6 subunit cytoplasmic domain in alpha 6 beta 1 integrin activation was examined. The use of P388D1 cells, an alpha 6-integrin deficient macrophage cell line, facilitated this analysis because expression of either the alpha 6A or alpha 6B subunit cDNAs restores their activation responsive laminin adhesion (Shaw, L. S., M. Lotz, and A. M. Mercurio. 1993. J. Biol. Chem. 268:11401-11408). A truncated alpha 6 cDNA, alpha 6-delta CYT, was constructed in which the human cytoplasmic domain sequence was deleted after the GFFKR pentapeptide. Expression of this cDNA in P388D1 cells resulted in the surface expression of a chimeric alpha 6-delta CYT beta 1 integrin that was unable to mediate laminin adhesion or increase this adhesion in response to PMA under normal conditions, i.e., in medium that contained physiological concentrations of Ca++ and Mg++. The alpha 6A-delta CYT transfectants adhered to laminin, however, when Ca++/Mg++ was replaced with 150 microM Mn++. We also assessed the role of serine phosphorylation in the regulation of alpha 6A beta 1 integrin function by site-directed mutagenesis of the two serine residues present in the alpha 6A cytoplasmic domain because this domain is phosphorylated on serine residues in response to stimuli that activate the laminin receptor function of alpha 6 A beta 1. Point mutations were introduced in the alpha 6A cDNA that changed either serine residue #1064 (M1) or serine residue #1071 (M2) to alanine residues. In addition, a double mutant (M3) was constructed in which both serine residues were changed to alanine residues. P388D1 transfectants which expressed these serine mutations adhered to laminin in response to PMA to the same extent as cells transfected with wild-type alpha 6A cDNA. These findings provide evidence for a novel mode of integrin regulation that is distinct from that reported for other regulated integrins (O\u27Toole, T. E., D. Mandelman, J. Forsyth, S. J. Shattil, E. F. Plow, and M. H. Ginsberg. 1991. Science (Wash. DC). 254:845-847. Hibbs, M. L., H. Xu, S. A. Stacker, and T. A. Springer. 1991. Science (Wash. DC). 251:1611-1613), and they demonstrate that serine phosphorylation of the alpha 6A cytoplasmic domain is not involved in this regulation

    Numerical simulations challenged on the prediction of massive subhalo abundance in galaxy clusters: the case of Abell 2142

    Get PDF
    In this Letter we compare the abundance of member galaxies of a rich, nearby (z=0.09z=0.09) galaxy cluster, Abell 2142, with that of halos of comparable virial mass extracted from sets of state-of-the-art numerical simulations, both collisionless at different resolutions and with the inclusion of baryonic physics in the form of cooling, star formation, and feedback by active galactic nuclei. We also use two semi-analytical models to account for the presence of orphan galaxies. The photometric and spectroscopic information, taken from the Sloan Digital Sky Survey Data Release 12 (SDSS DR12) database, allows us to estimate the stellar velocity dispersion of member galaxies of Abell 2142. This quantity is used as proxy for the total mass of secure cluster members and is properly compared with that of subhalos in simulations. We find that simulated halos have a statistically significant (≳7\gtrsim 7 sigma confidence level) smaller amount of massive (circular velocity above 200 km s−1200\,{\rm km\, s^{-1}}) subhalos, even before accounting for the possible incompleteness of observations. These results corroborate the findings from a recent strong lensing study of the Hubble Frontier Fields galaxy cluster MACS J0416 \citep{grillo2015} and suggest that the observed difference is already present at the level of dark matter (DM) subhalos and is not solved by introducing baryonic physics. A deeper understanding of this discrepancy between observations and simulations will provide valuable insights into the impact of the physical properties of DM particles and the effect of baryons on the formation and evolution of cosmological structures.Comment: 8 pages, 2 figures. Modified to match the version published in ApJ

    Therapeutic Approaches to Aggressive Carcinomas Based on a Novel VEGF/Neuropilin Autocrine Pathway

    Get PDF
    Summary: Autocrine VEGF signaling in tumor cells contributes to de-differentiation and function of tumor initiating/stem cells. NRP2 is the nexus of a signaling pathway that promotes de-differentiation and sustains tumor initiating/stem sells. Anti-NRP2 therapy is worth pursuing, especially for high-grade cancers. Therapeutic Abs are available. This presentation was part of the retreat mini-symposium entitled: Biomarker Discovery and Targeted Therapeutics in Cancer
    • 

    corecore