5,863 research outputs found
DIT scores and political ideology: evidence of a non-significant relationship
The present study was motivated by concern about the validity of the DIT and methodological issues in Fisher and Sweeney (2001, 1998) studies. Our study of 98 accounting students from three private institutions in the eastern U.S. generates results that directly contradict those of Fisher and Sweeneyâs (1998). Using the nine-point scale, we could reject our three hypotheses relating to DIT scores associating with political orientation. First, we find that there was not a significant difference between the pre-test DIT scores of liberal and conservative politically orientated students. Second, the follow on DIT test scores for those students who were not politically conservative did not decrease when responding from a conservative perspective. Third, the follow on DIT test scores for those students who were not politically liberal did not increase when responding from a liberal perspective
The influence of political ideology on DIT scores: fact or artifact?
Concern about the validity of the DIT and Fisher and Sweeneyâs measurement of conservative, moderate and liberal political orientation using a seven-point Likert scale motivates our study. We perform two experiments to investigate these interrelated issues. First, we assess the degree to which 569 undergraduate studentsâ political orientation as measured by a seven-point Likert scale associates with their corresponding political orientation as measured by a ninepoint Likert scale. We find differences in categorization of subjects depending upon scale used, suggesting problems with the sampling distribution arise when a seven-point Likert scale is used for categorizing subjects. Second, we measure 115 studentsâ political orientation utilizing a nine-point Likert scale to assess Fisher and Sweeneyâs findings. Our results suggest that Fisher and Sweeneyâs findings may relate to their using a seven-point Likert scale in measuring political orientation rather than a flaw in the DITâs validity resulting from an embedded political ideology
Polarization observations in a low synchrotron emission field at 1.4 GHz
We present the first observation of the diffuse polarized synchrotron
radiation of a patch () in the BOOMERanG field,
one of the areas with the lowest CMB foreground emission. The work has been
carried out with the Australia Telescope Compact Array at 1.4 GHz with 3.4
arcmin resolution and sensitivity of mJy beam. The mean
polarized signal has been found to be mK, nearly one order of magnitude below than in the Galactic
Plane.
Extrapolations to frequencies of interest for cosmological investigations
suggest that polarized synchrotron foreground noise should allow the detection
of the CMB Polarization --mode already at 32 GHz and make us confident that,
at 90 GHz, it is accessible with no relevant foreground contamination. Last but
not least, even the --mode detection for is not ruled out in
such a low emission patch.Comment: Uses emulateapj.sty, onecolfloat.sty, 5 pages 4 fig., accepted for
publication in ApJ
New stopping criteria for segmenting DNA sequences
We propose a solution on the stopping criterion in segmenting inhomogeneous
DNA sequences with complex statistical patterns. This new stopping criterion is
based on Bayesian Information Criterion (BIC) in the model selection framework.
When this stopping criterion is applied to a left telomere sequence of yeast
Saccharomyces cerevisiae and the complete genome sequence of bacterium
Escherichia coli, borders of biologically meaningful units were identified
(e.g. subtelomeric units, replication origin, and replication terminus), and a
more reasonable number of domains was obtained. We also introduce a measure
called segmentation strength which can be used to control the delineation of
large domains. The relationship between the average domain size and the
threshold of segmentation strength is determined for several genome sequences.Comment: 4 pages, 4 figures, Physical Review Letters, to appea
Dynamic Simulations of the Kosterlitz-Thouless Phase Transition
Based on the short-time dynamic scaling form, a novel dynamic approach is
proposed to tackle numerically the Kosterlitz-Thouless phase transition. Taking
the two-dimensional XY model as an example, the exponential divergence of the
spatial correlation length, the transition temperature and all
critical exponents are computed. Compared with Monte Carlo simulations in
equilibrium, we obtain data at temperatures nearer to .Comment: to appear in Phys. Rev. E in Rapid Communicatio
Caracterização do perfil sorolĂłgico de nulĂparas suĂnas e da progĂȘnie frente ao parvovĂrus suĂno.
Projeto: 03.09.00.046
The Black Hole-Bulge Relationship in Luminous Broad-Line Active Galactic Nuclei and Host Galaxies
We have measured the stellar velocity dispersions (\sigma_*) and estimated
the central black hole (BH) masses for over 900 broad-line active galactic
nuclei (AGNs) observed with the Sloan Digital Sky Survey. The sample includes
objects which have redshifts up to z=0.452, high quality spectra, and host
galaxy spectra dominated by an early-type (bulge) component. The AGN and host
galaxy spectral components were decomposed using an eigenspectrum technique.
The BH masses (M_BH) were estimated from the AGN broad-line widths, and the
velocity dispersions were measured from the stellar absorption spectra of the
host galaxies. The range of black hole masses covered by the sample is
approximately 10^6 < M_BH < 10^9 M_Sun. The host galaxy luminosity-velocity
dispersion relationship follows the well-known Faber-Jackson relation for
early-type galaxies, with a power-law slope 4.33+-0.21. The estimated BH masses
are correlated with both the host luminosities (L_{H}) and the stellar velocity
dispersions (\sigma_*), similar to the relationships found for low-redshift,
bulge-dominated galaxies. The intrinsic scatter in the correlations are large
(~0.4 dex), but the very large sample size allows tight constraints to be
placed on the mean relationships: M_BH ~ L_H^{0.73+-0.05} and M_BH ~
\sigma_*^{3.34+-0.24}. The amplitude of the M_BH-\sigma_* relation depends on
the estimated Eddington ratio, such that objects with larger Eddington ratios
have smaller black hole masses than expected at a given velocity dispersion.Comment: Accepted for publication in A
Constraints on a Massive Dirac Neutrino Model
We examine constraints on a simple neutrino model in which there are three
massless and three massive Dirac neutrinos and in which the left handed
neutrinos are linear combinations of doublet and singlet neutrinos. We examine
constraints from direct decays into heavy neutrinos, indirect effects on
electroweak parameters, and flavor changing processes. We combine these
constraints to examine the allowed mass range for the heavy neutrinos of each
of the three generations.Comment: latex, 29 pages, 7 figures (not included), MIT-CTP-221
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