3,294 research outputs found
Natural zeolites and white wines from Campania region (Southern Italy): a new contribution for solving some oenological problems
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
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
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
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
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
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
In this Letter we compare the abundance of member galaxies of a rich, nearby
() 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 ( sigma confidence level)
smaller amount of massive (circular velocity above )
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
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
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Search for lepton flavour violation in the eÎŒ continuum with the ATLAS detector in âs = 7 TeV pp collisions at the LHC
This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark (t) in the e^± ÎŒ^â continuum using 2.1 fb^(â1) of data collected by the ATLAS detector in âs = 7 TeV pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95 % C.L. are calculated as a function of the scalar top mass (mt). The upper limits on the production cross section for pp â eÎŒX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for m_t=95 GeV to 30 fb for m_t=1000 GeV
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A search for tt resonances with the ATLAS detector in 2.05 fb^(â1) of proton-proton collisions at âs =7 TeV
A search for top quark pair resonances in final states containing at least one electron or muon has been performed with the ATLAS experiment at the CERN Large Hadron Collider. The search uses a data sample corresponding to an integrated luminosity of 2.05 fb^(â1), which was recorded in 2011 at a proton-proton centre-of-mass energy of 7 TeV. No evidence for a resonance is found and limits are set on the production cross-section times branching ratio to tt for narrow and wide resonances. For narrow ZâČ bosons, the observed 95 % Bayesian credibility level limits range from 9.3 pb to 0.95 pb for masses in the range of m_(ZâČ)=500 GeV to m_(ZâČ)=1300 GeV. The corresponding excluded mass region for a leptophobic topcolour ZâČ boson (Kaluza-Klein gluon excitation in the Randall-Sundrum model) is m_(ZâČ)<880 GeV (m_(gKK)< 1130 GeV)
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