6,019 research outputs found
Price Discount Perception: Consumers\u27 Numeric Interpretation of Semantic Price Claims
Behavioral pricing research includes a considerable amount of focus on the effects of semantic cues (phrases) used to label reference and offer prices in price promotions, but a related type of semantic claim also frequently used in price promotions has continued to escape research attention - claims that attempt to encourage purchases by describing the consequences of buying at the discounted price (e.g. Super Savings). Using a variety of methods and conceptual foundations, the present research is the first to comprehensively study consumers\u27 discount and value associations of these semantic claims. In a series of three studies, we find evidence suggesting that at least some semantic claims have consistent numerical interpretations and a subset of those were found to influence discount expectations and perceptions of both transaction and acquisition value. These findings suggest the importance of recognizing that consumers may associate specific claims with certain discount magnitudes
Cation composition effects on oxide conductivity in the Zr_2Y_2O_7-Y_3NbO_7 system
Realistic, first-principles-based interatomic potentials have been used in
molecular dynamics simulations to study the effect of cation composition on the
ionic conductivity in the Zr2Y2O7-Y3NbO7 system and to link the dynamical
properties to the degree of lattice disorder. Across the composition range,
this system retains a disordered fluorite crystal structure and the vacancy
concentration is constant. The observed trends of decreasing conductivity and
increasing disorder with increasing Nb5+ content were reproduced in simulations
with the cations randomly assigned to positions on the cation sublattice. The
trends were traced to the influences of the cation charges and relative sizes
and their effect on vacancy ordering by carrying out additional calculations in
which, for example, the charges of the cations were equalised. The simulations
did not, however, reproduce all the observed properties, particularly for
Y3NbO7. Its conductivity was significantly overestimated and prominent diffuse
scattering features observed in small area electron diffraction studies were
not always reproduced. Consideration of these deficiencies led to a preliminary
attempt to characterise the consequence of partially ordering the cations on
their lattice, which significantly affects the propensity for vacancy ordering.
The extent and consequences of cation ordering seem to be much less pronounced
on the Zr2Y2O7 side of the composition range.Comment: 22 pages, 8 figures, submitted to Journal of Physics: Condensed
Matte
Prevalência e formas clínicas de Trypanosoma cruzi em candidatos a doadores de sangue no Brasil
A prevalência e a manifestação das formas clinicas de Trypanosoma cruzi foram avaliadas em candidatos a doadores de sangue atendidos em um hospital geral de Nova Iguaçu, Rio de Janeiro, Brasil, no período de janeiro de 1997 a abril de 1999. A pesquisa sorológica foi realizada por meio do teste de hemaglutinação indireta e confirmada pelo ELISA. Os dados foram coletados considerando os exames clínicos, eletrocardiograma convencional, radiografia de tórax e ecocardiografia. Os resultados demonstraram que, apesar da prevalência ser de 1,17% (128 pacientes), principalmente entre homens com idade igual ou superior a 40 anos, 70,8%, principalmente de homens entre 19 e 39 anos, demonstraram alterações que permitiram o diagnóstico de cardiopatias e/ou esofagopatias, ratificando mais uma vez sua importância nos centros urbanos.The prevalence and clinical forms of Trypanosoma cruzi were evaluated among blood donor candidates attended at a general hospital in Rio de Janeiro, Brazil, from January 1997 to April 1999. The investigation was done by means of the indirect hemagglutination test and was confirmed via ELISA. Data were collected from clinical examinations, conventional electrocardiogram, chest radiography and echocar-diography. The results showed that despite Trypanosoma cruzi prevalence of 1.17% (128 patients), mainly in males aged 40 years or over, 70.8% of these patients, mainly males aged 19 to 39 years, demonstrated abnormalities that allowed the diagnosis of cardiopathy and/or esophagopathy. This once again corroborates the importance of Trypanosoma cruzi infection in urban centers
High-pressure behaviour of GeO2: a simulation study
In this work we study the high pressure behaviour of liquid and glassy GeO2
by means of molecular dynamics simulations. The interaction potential, which
includes dipole polarization effects, was parameterized from first-principles
calculations. Our simulations reproduce the most recent experimental data to a
high degree of precision. The proportion of the various GeOn polyhedra is
determined as a function of the pressure: a smooth transition from tetrahedral
to octahedral network is observed. Finally, the study of high-pressure, liquid
germania confirms that this material presents an anomalous behaviour of the
diffusivity as observed in analog systems such as silica and water. The
importance of penta-coordinated germanium ions for such behaviour is stressed.Comment: 16 pages, 4 figures, accepted as a Fast Track Communication on
Journal of Physics: Condensed Matte
The angular correlations of galaxies in the COSMOS field
We present measurements of the two-point galaxy angular correlation function
w(\theta) in the COSMOS field. Independent determinations of w(\theta) as a
function of magnitude limit are presented for both the HST ACS catalog and also
for the ground-based data from Subaru and the CFHT. Despite having
significantly different masks, these three determinations agree well. At bright
magnitudes (IAB<22), our data generally match very well with existing
measurements and with mock catalogs based on semi-analytic galaxy formation
calculations of Kitzbichler and White from the Millennium Simulation. The
exception is that our result is at the upper end of the expected cosmic
variance scatter for \theta > 10 arcmin, which we attribute to a particularly
rich structure known to exist at z~0.8. For fainter samples, however, the level
of clustering is somewhat higher than reported by some previous studies: in all
three catalogues we find w(\theta=1')~0.014 at a median IAB magnitude of 24. At
these very faintest magnitudes, our measurements agree well with the latest
determinations from the Canada-France Legacy Survey. This level of clustering
is approximately double what is predicted by the semi-analytic catalogs (at all
angles). The semi-analytic results allow an estimate of cosmic variance, which
is too small to account for the discrepancy. We therefore conclude that the
mean amplitude of clustering at this level is higher than previously estimated.Comment: Six pages, five figures. Accepted for publication in the ApJS COSMOS
special issue, Sept. 200
High-Mass Proto-Stellar Candidates - I : The Sample and Initial Results
We describe a systematic program aimed at identifying and characterizing
candidate high-mass proto-stellar objects (HMPOs). Our candidate sample
consists of 69 objects selected by criteria based on those established by
Ramesh & Sridharan (1997) using far-infrared, radio-continuum and molecular
line data. Infrared-Astronomical-Satellite (IRAS) and
Midcourse-Space-Experiment (MSX) data were used to study the larger scale
environments of the candidate sources and to determine their total luminosities
and dust temperatures. To derive the physical and chemical properties of our
target regions, we observed continuum and spectral line radiation at millimeter
and radio wavelengths. We imaged the free-free and dust continuum emission at
wavelengths of 3.6 cm and 1.2 mm, respectively, searched for H2O and CH3OH
maser emission and observed the CO 2-1 and several NH3 lines toward all sources
in our sample. Other molecular tracers were observed in a subsample. The
presented results indicate that a substantial fraction of our sample harbors
HMPOs in a pre-UCHII region phase, the earliest known stage in the high-mass
star formation process.Comment: 16 pages, 11 eps-figures. Astrophysical Journal, in pres
The Millennium Galaxy Catalogue: the photometric accuracy, completeness and contamination of the 2dFGRS and SDSS-EDR/DR1 data sets
The Millennium Galaxy Catalogue (MGC) is a deep (μB,lim = 26 mag arcsec−2), wide-field, charge-coupled device imaging survey, covering 37.5 deg2. The MGC survey region is completely contained within the Two-Degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey Early Data Release (SDSS-EDR). We compare the photometry and completeness of the 2dFGRS and the SDSS-EDR with the MGC over the range 16 < B < 20 mag. We have also undertaken a photometric comparison to SuperCosmos (SCOS) and the Sloan Digital Sky Survey First Data Release (SDSS-DR1). We find that BMGC−B2dF = (0.035 ± 0.005) mag with an uncertainty of 0.142 mag per galaxy; BMGC−BSCOS = (0.032 ± 0.005) mag with an uncertainty of 0.108 mag; BMGC−BSDSS-EDR = (0.032 ± 0.005) mag with an uncertainty of 0.094 mag; and BMGC−BSDSS-DR1 = (0.039 ± 0.005) mag with an uncertainty of 0.086 mag. We find that high surface brightness 2dFGRS galaxies are systematically too faint, which leads to a significant scale error in magnitude. This effect is significantly reduced with the SCOS photometry. In the SDSS there is a weak non-linear scale error, which is negligible for faint galaxies. Low surface brightness galaxies in the SDSS are systematically fainter, consistent with the relative shallowness of this survey. We find that the 2dFGRS catalogue has (5.2 ± 0.3) per cent stellar contamination, (7.0 ± 0.4) per cent of objects resolved into two or more by the MGC, and is (8.7 ± 0.6) per cent incomplete compared to the MGC. From our all-object spectroscopic survey we find that the MGC is itself misclassifying (5.6 ± 1.3) per cent of galaxies as stars, and hence the 2dFGRS misses (14.3 ± 1.4) per cent of the galaxy population. The SDSS-EDR galaxy catalogue has (1.3 ± 0.1) per cent stellar contamination and (5.3 ± 1.0) per cent of galaxies misclassified as stars, with (0.18 ± 0.04) per cent of objects resolved into two or more by the MGC, and is (1.8 ± 0.1) per cent incomplete compared to the MGC. The total fraction of galaxies missing from the SDSS-EDR galaxy catalogue to BMGC = 20 mag, from incompleteness and misclassification, is (7.1 ± 1.0) per cen
Additive CHARMM force field for naturally occurring modified ribonucleotides
International audienceMore than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all-atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. (C) 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc
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