1,077 research outputs found
The association of family and peer factors with tobacco, alcohol, and marijuana use among Chilean adolescents in neighborhood context
Research on adolescent use of substances has long sought to understand the family factors that may be associated with use of different substances such as alcohol, tobacco and marijuana. However, scant attention has been focused on these questions in Latin American contexts, despite growing concerns about substance use among Latin American youth. Using data from a sample of 866 Chilean youth, we examined the relationship of family and neighborhood factors with youth substance abuse. We found that in a Latin American context access to substances is an important predictor of use, but that neighborhood effects differ for marijuana use as opposed to cigarettes or alcohol. Age of youth, family and peer relationships, and gender all play significant roles of substance use.The study findings provide additional evidence that the use of substances is complex whereby individual, family, and community influences must be considered jointly to prevent or reduce substance use among adolescents.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249750/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249750/Accepted manuscrip
Comics and human rights: an interview with the team behind Sogi’s Story
Professor Andrea Durbach is Director of the Australian Human Rights Centre in the Faculty of Law at UNSW, where she co-directs projects on health and human rights, and transformative reparations and gender violence post-conflict. Andrea was Deputy Sex Discrimination Commissioner at the Australian Human Rights Commission in 2011-2012. Jed Horner is a Project Director on health, sexual orientation and human rights at the Australian Human Rights Centre and a PhD candidate at UNSW. Previously, he worked as an external advisor to the New Zealand Human Rights Commission and Office of the Children’s Commissioner (Young Peoples Reference Group). Interview conducted by Andrew Small (@_ansmall), Lead Editor of the LSE Human Rights Blog
A New Kinematic Distance Estimator to the LMC
The distance to the Large Magellanic Cloud (LMC) can be directly determined
by measuring three of its properties, its radial-velocity field, its mean
proper motion, and the position angle \phi_ph of its photometric line of nodes.
Statistical errors of 2% are feasible based on proper motions obtained with any
of several proposed astrometry satellites, the first possibility being the
Full-Sky Astrometric Mapping Explorer (FAME). The largest source of systematic
error is likely to be in the determination of \phi_ph. I suggest two
independent methods to measure \phi_ph, one based on counts of clump giants and
the other on photometry of clump giants. I briefly discuss a variety of methods
to test for other sources of systematic errors.Comment: submitted to ApJ, 13 page
Vertical Boil Propagation from a Submerged Estuarine Sill
Surface disruptions by boils during strong tidal flows over a rocky sill were observed in thermal infrared imagery collected at the Snohomish River estuary in Washington State. Locations of boil disruptions and boil diameters at the surface were quantified and are used to test an idealized model of vertical boil propagation. The model is developed as a two-dimensional approximation of a three-dimensional vortex loop, and boil vorticity is derived from the flow shear over the sill. Predictions of boil disruption locations were determined from the modeled vertical velocity, the sill depth, and the over-sill velocity. Predictions by the vertical velocity model agree well with measured locations (rms difference 3.0 m) and improve by using measured velocity and shear (rms difference 1.8 m). In comparison, a boil-surfacing model derived from laboratory turbulent mixed-layer wakes agrees with the measurements only when stratification is insignificant
Fractal timing in computer music : a MIDI implementation
Human musical performance is filled with subtle nuances and intricate timing relationships, which makes its simulation a complex task for the computer. Various efforts in realizing dynamic tempos and phrasings have applied a process, termed time warping , utilizing simple linear or polynomial functions. This paper introduces the use of fractal functions in this time warping process.
By utilizing the Macintosh computer and a specialized file format, standard among MIDI software and hardware, a time warping application was developed which included both conventional functions and those generated by a fractal process. With this implementation in place, examples were tried, and the results gathered.
These results demonstrated that the fractal process was effective in generating aesthetically pleasing musical transitions. In addition, the fractal results were wideranging in character and thus suited to various musical contexts. The author\u27s composition. Clockwork, provided an opportunity to use the process in a real musical piece. Thus, fractal warping was determined to be effective in the creation of computer music nuances and phrasings
A systematic review of the energy and climate impacts of teleworking
Information and communication technologies (ICTs) increasingly enable employees to work from home and other locations (‘teleworking’). This study explores the extent to which teleworking reduces the need to travel to work and the consequent impacts on economy-wide energy consumption.
Methods/Design: The paper provides a systematic review of the current state of knowledge of the energy impacts of teleworking. This includes the energy savings from reduced commuter travel and the indirect impacts on energy consumption associated with changes in non-work travel and home energy consumption. The aim is to identify the conditions under which teleworking leads to a net reduction in economy-wide energy consumption, and the circumstances where benefits may be outweighed by unintended impacts. The paper synthesises the results of 39 empirical studies, identified through a comprehensive search of 9,000 published articles.
Review results/Synthesis: Twenty six of the 39 studies suggest that teleworking reduces energy use, and only eight studies suggest that teleworking increases, or has a neutral impact on energy use. However, differences in the methodology, scope and assumptions of the different studies make it difficult to estimate ‘average’ energy savings. The main source of savings is the reduced distance travelled for commuting, potentially with an additional contribution from lower office energy consumption. However, the more rigorous studies that include a wider range of impacts (e.g. non-work travel or home energy use) generally find smaller savings.
Discussion: Despite the generally positive verdict on teleworking as an energy-saving practice, there are numerous uncertainties and ambiguities about its actual or potential benefits. These relate to the extent to which teleworking may lead to unpredictable increases in non-work travel and home energy use that may outweigh the gains from reduced work travel. The available evidence suggests that economy-wide energy savings are typically modest, and in many circumstances could be negative or non-existent
Can simulations reproduce the observed temperature-mass relation for clusters of galaxies?
It has become increasingly apparent that traditional hydrodynamical
simulations of galaxy clusters are unable to reproduce the observed properties
of galaxy clusters, in particular overpredicting the mass corresponding to a
given cluster temperature. Such overestimation may lead to systematic errors in
results using galaxy clusters as cosmological probes, such as constraints on
the density perturbation normalization sigma_8. In this paper we demonstrate
that inclusion of additional gas physics, namely radiative cooling and a
possible preheating of gas prior to cluster formation, is able to bring the
temperature-mass relation in the innermost parts of clusters into good
agreement with recent determinations by Allen, Schmidt & Fabian using Chandra
data.Comment: 5 pages, submitted to MNRA
Lead in exterior paints from the urban and suburban environs of Plymouth, south west England
The dry weight concentrations of lead in paints on a variety of structures in the urban and suburban environs of a British city (Plymouth, south west England) have been determined in situ and ex situ by field-portable x-ray fluorescence spectrometry. Lead was detected in 221 out of 272 analyses, with overall median and mean concentrations of 4180 g g-1 and 29,300 g g-1, respectively, and a maximum concentration of 390,000 g g-1. The highest concentrations were observed in extant paints on poorly maintained, metallic structures, including railings, gates, telephone kiosks and bridges, in various yellow road line paints, and in paints of varying condition on public playground facilities (ramps, climbing frames, monkey bars). Occupants of households in the vicinity of structures that are shedding leaded paint are at potential risk of exposure from paint particles being tracked in on shoes while children in contact with leaded paints in playgrounds and recreational areas are at potential risk from the direct ingestion of paint flakes. Since the issues highlighted in the present study are neither likely to be restricted to this city, nor to the UK, a greater, general awareness and understanding of the sources and routes of exposure of exterior leaded paint is called for
First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)
The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated
observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec
spectrograph. The MINERVA mission is to discover super-Earths in the habitable
zones of nearby stars. This can be accomplished with MINERVA's unique
combination of high precision and high cadence over long time periods. In this
work, we detail changes to the MINERVA facility that have occurred since our
previous paper. We then describe MINERVA's robotic control software, the
process by which we perform 1D spectral extraction, and our forward modeling
Doppler pipeline. In the process of improving our forward modeling procedure,
we found that our spectrograph's intrinsic instrumental profile is stable for
at least nine months. Because of that, we characterized our instrumental
profile with a time-independent, cubic spline function based on the profile in
the cross dispersion direction, with which we achieved a radial velocity
precision similar to using a conventional "sum-of-Gaussians" instrumental
profile: 1.8 m s over 1.5 months on the RV standard star HD 122064.
Therefore, we conclude that the instrumental profile need not be perfectly
accurate as long as it is stable. In addition, we observed 51 Peg and our
results are consistent with the literature, confirming our spectrograph and
Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte
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