6,726 research outputs found
The Salience of Vomiting in Teenagers Binge Drinking Intentions
Binge drinking among Australian teenagers has been identified as a serious health issue. Unfortunately, efforts to date to address this problem have been largely ineffective. It has been suggested that using images of teenagers vomiting in social marketing campaigns isnât effective because vomiting is viewed as a positive outcome due its ability to signify a âbig nightâ. The present study accessed online information posted by Australian teenagers to explore alcohol-related beliefs and behaviours that are reported online. A thematic analysis of the blogs suggests that for many Australian teenagers vomiting is still a deterrent to heavy drinking, and that they may be turning to illicit drugs to achieve an altered mental state with a lower risk of vomiting
Polynomial super-gl(n) algebras
We introduce a class of finite dimensional nonlinear superalgebras providing gradings of . Odd generators close by anticommutation on polynomials (of
degree ) in the generators. Specifically, we investigate `type I'
super- algebras, having odd generators transforming in a single
irreducible representation of together with its contragredient.
Admissible structure constants are discussed in terms of available
couplings, and various special cases and candidate superalgebras are identified
and exemplified via concrete oscillator constructions. For the case of the
-dimensional defining representation, with odd generators , and even generators , , a three
parameter family of quadratic super- algebras (deformations of
) is defined. In general, additional covariant Serre-type conditions
are imposed, in order that the Jacobi identities be fulfilled. For these
quadratic super- algebras, the construction of Kac modules, and
conditions for atypicality, are briefly considered. Applications in quantum
field theory, including Hamiltonian lattice QCD and space-time supersymmetry,
are discussed.Comment: 31 pages, LaTeX, including minor corrections to equation (3) and
reference [60
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Visualisation of Origins, Destinations and Flows with OD Maps
We present a new technique for the visual exploration of origins (O) and destinations (D) arranged in geographic space. Previous attempts to map the flows between origins and destinations have suffered from problems of occlusion usually requiring some form of generalisation, such as aggregation or flow density estimation before they can be visualized. This can lead to loss of detail or the introduction of arbitrary artefacts in the visual representation. Here, we propose mapping OD vectors as cells rather than lines, comparable with the process of constructing OD matrices, but unlike the OD matrix, we preserve the spatial layout of all origin and destination locations by constructing a gridded twoâlevel spatial treemap. The result is a set of spatially ordered small multiples upon which any arbitrary geographic data may be projected. Using a hash grid spatial data structure, we explore the characteristics of the technique through a software prototype that allows interactive query and visualisation of 105â106 simulated and recorded OD vectors. The technique is illustrated using US county to county migration and commuting statistics
CIV 1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei
[Abridged] We have been exploring a spectroscopic unification for all known
types of broad line emitting AGN. The 4D Eigenvector 1 (4DE1) parameter space
shows promise as a unification capable of organizing quasar diversity on a
sequence primarily governed by Eddington ratio. This paper considers the role
of CIV 1549 measures with special emphasis on the CIV 1549 line shift as a
principal 4DE1 diagnostic. We use HST archival spectra for 130 sources with S/N
high enough to permit reliable CIV 1549 broad component (BC) measures. We find
a CIV 1549 BC profile blueshift that is strongly concentrated among (largely
radio-quiet: RQ) sources with FWHM(H beta BC) < 4000 km/s (which we call
Population A). Narrow line Seyfert 1 (NLSy1, with FWHM H beta < 2000 km/s)
sources belong to this population but do not emerge as a distinct class. The
systematic blueshift, widely interpreted as arising in a disk wind/outflow, is
not observed in broader lined AGN which we call Population B. We find new
correlations between FWHM(CIV 1549 BC) and CIV 1549 line shift as well as the
equivalent width of CIV 1549. They are seen only in Pop. A sources. CIV 1549
measures enhance the apparent dichotomy at FWHM(Hbeta BC) approx. 4000 \kms\
(Sulentic et al. 2000) suggesting that it has more significance in the context
of Broad Line Region structure than the more commonly discussed RL vs. RQ
dichotomy. Black hole masses computed from FWHM CIV 1549 BC for about 80 AGN
indicate that the CIV 1549 width is a poor virial estimator. Comparison of mass
estimates derived from Hbeta BC and CIV 1549 reveals that the latter show
different and nonlinear offsets for population A and B sources. A significant
number of sources also show narrow line CIV 1549 emission. We present a recipe
for CIV 1549 narrow component extraction.Comment: Accepted for publication in the Astrophysical Journa
Molecular Gas in Candidate Double Barred Galaxies III. A Lack of Molecular Gas?
Most models of double-barred galaxies suggest that a molecular gas component
is crucial for maintaining long-lived nuclear bars. We have undertaken a CO
survey in an attempt to determine the gas content of these systems and to
locate double barred galaxies with strong CO emission that could be candidates
for high resolution mapping. We observed 10 galaxies in CO J=2-1 and J=3-2 and
did not detect any galaxies that had not already been detected in previous CO
surveys. We preferentially detect emission from galaxies containing some form
of nuclear activity. Simulations of these galaxies require that they contain 2%
to 10% gas by mass in order to maintain long-lived nuclear bars. The fluxes for
the galaxies for which we have detections suggest that the gas mass fraction is
in agreement with these models requirements. The lack of emission in the other
galaxies suggests that they contain as little as 7 x 10^6 solar masses of
molecular material which corresponds to < 0.1% gas by mass. This result
combined with the wide variety of CO distributions observed in double barred
galaxies suggests the need for models of double-barred galaxies that do not
require a large, well ordered molecular gas component.Comment: 17 pages (3 figures embedded on pg 17). To appear in the March 10
issue of the Astrophysical Journa
Entanglement of superconducting charge qubits by homodyne measurement
We present a scheme by which projective homodyne measurement of a microwave
resonator can be used to generate entanglement between two superconducting
charge qubits coupled to this resonator. The non-interacting qubits are
initialised in a product of their ground states, the resonator is initialised
in a coherent field state, and the state of the system is allowed to evolve
under a rotating wave Hamiltonian. Making a homodyne measurement on the
resonator at a given time projects the qubits into an state of the form (|gg> +
exp(-i phi)|ee>)/sqrt(2). This protocol can produce states with a fidelity as
high as required, with a probability approaching 0.5. Although the system
described is one that can be used to display revival in the qubit oscillations,
we show that the entanglement procedure works at much shorter timescales.Comment: 17 pages, 7 figure
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