326 research outputs found
Creativity for Sale
This project focuses on a business plan and template for developing proposals for potential clients. This covers the history of Creative Problem Solving (CPS); the effectiveness of CPS training; an example design of a workshop; business plan; memorandum of understanding; contract; and a template for fees. This project will add to the richness of the department, and create opportunities for our faculty, alumni, and current students to consult while spreading the CPS process and creativity around the world
Engaging Students With Course Content Using Scheduled and Unscheduled Emails and Text Messages
This study addressed college studentsâ acceptance of push communication (i.e., email and SMS messaging) as a means of receiving course-related content, and modified the Unified Theory of Acceptance and Use of Technology by including Scheduled Message as an independent variable. Surveys of 301 studentsâ perceptions of instructor-sent email and SMS texts directing them to materials in six instructorsâ 10 courses were analyzed by PLS-PM for their impact on the studentsâ intention to use these push communication technologies. In contrast to previous studies on technology acceptance, we evaluated actual usage patterns for both the scheduled and unscheduled push communication. Scheduled emails did not yield higher average duration times or unique visitors than unscheduled ones, yet click-through rates and return visits were higher. Scheduled SMS messages did yield higher average duration times, unique visitors, and click-through rates than unscheduled SMS messages, yet unscheduled SMS messages yielded more return visits. We argue that the differences in the results for email vs. SMS may have been due to emailâs slower delivery time. We also consider implications for faculty wishing to facilitate distributed learning among students via push communication
Engaging Students With Course Content Using Scheduled and Unscheduled Emails and Text Messages
This study addressed college studentsâ acceptance of push communication (i.e., email and SMS messaging) as a means of receiving course-related content, and modified the Unified Theory of Acceptance and Use of Technology by including Scheduled Message as an independent variable. Surveys of 301 studentsâ perceptions of instructor-sent email and SMS texts directing them to materials in six instructorsâ 10 courses were analyzed by PLS-PM for their impact on the studentsâ intention to use these push communication technologies. In contrast to previous studies on technology acceptance, we evaluated actual usage patterns for both the scheduled and unscheduled push communication. Scheduled emails did not yield higher average duration times or unique visitors than unscheduled ones, yet click-through rates and return visits were higher. Scheduled SMS messages did yield higher average duration times, unique visitors, and click-through rates than unscheduled SMS messages, yet unscheduled SMS messages yielded more return visits. We argue that the differences in the results for email vs. SMS may have been due to emailâs slower delivery time. We also consider implications for faculty wishing to facilitate distributed learning among students via push communication
LoCuSS: A Comparison of Sunyaev-Zel'dovich Effect and Gravitational Lensing Measurements of Galaxy Clusters
We present the first measurement of the relationship between the
Sunyaev-Zel'dovich effect signal and the mass of galaxy clusters that uses
gravitational lensing to measure cluster mass, based on 14 X-ray luminous
clusters at z~0.2 from the Local Cluster Substructure Survey. We measure the
integrated Compton y-parameter, Y, and total projected mass of the clusters
(M_GL) within a projected clustercentric radius of 350 kpc, corresponding to
mean overdensities of 4000-8000 relative to the critical density. We find
self-similar scaling between M_GL and Y, with a scatter in mass at fixed Y of
32%. This scatter exceeds that predicted from numerical cluster simulations,
however, it is smaller than comparable measurements of the scatter in mass at
fixed T_X. We also find no evidence of segregation in Y between disturbed and
undisturbed clusters, as had been seen with T_X on the same physical scales. We
compare our scaling relation to the Bonamente et al. relation based on mass
measurements that assume hydrostatic equilibrium, finding no evidence for a
hydrostatic mass bias in cluster cores (M_GL = 0.98+/-0.13 M_HSE), consistent
with both predictions from numerical simulations and lensing/X-ray-based
measurements of mass-observable scaling relations at larger radii. Overall our
results suggest that the Sunyaev-Zel'dovich effect may be less sensitive than
X-ray observations to the details of cluster physics in cluster cores.Comment: Minor changes to match published version: 2009 ApJL 701:114-11
Gender-based violence-supportive cognitions in adolescent girls and boys: The function of violence exposure and victimisation
Violence against women and girls is widespread in the Caribbean, which may be due to heightened acceptance of such acts in this specific social context. In spite of this, studies investigating attitudes towards violence and their correlates among participants drawn from the region are missing. In order to address this void in the literature, we examined associations between violence exposure and victimisation and two gender-based violence-related cognitions (attitudes towards male physical domestic violence and social norms regarding physical violence against girls) as well as general beliefs about violence, using structural equation modelling. Participants were a sample of adolescent girls (n = 661; M age = 13.15) and boys (n = 639; M age = 13.22) from two Eastern Caribbean countries, Barbados and Grenada, recruited from 10 primary schools, nine secondary schools, and two youth offender centres. In considering that girls and boys were previously demonstrated to differ in their experiences as well as tolerance of violence, structural models were specified and tested separately for the two sexes. Results indicated that violence victimisation was positively strongly associated with attitudes towards male physical domestic violence and social norms regarding physical violence against girls among boys. Increased violence victimisation among girls, in turn, correlated with increased acceptance of social norms regarding physical violence against girls, but this relationship was weak. Violence exposure did not have any significant associations with any of the attitudinal variables included in the study. We discuss the importance of these findings for the development of appropriate gender-based violence prevention strategies for youths from the Eastern Caribbean
Joint analysis of X-ray and Sunyaev Zel'dovich observations of galaxy clusters using an analytic model of the intra-cluster medium
We perform a joint analysis of X-ray and Sunyaev Zel'dovich (SZ) effect data
using an analytic model that describes the gas properties of galaxy clusters.
The joint analysis allows the measurement of the cluster gas mass fraction
profile and Hubble constant independent of cosmological parameters. Weak
cosmological priors are used to calculate the overdensity radius within which
the gas mass fractions are reported. Such an analysis can provide direct
constraints on the evolution of the cluster gas mass fraction with redshift. We
validate the model and the joint analysis on high signal-to-noise data from the
Chandra X-ray Observatory and the Sunyaev-Zel'dovich Array for two clusters,
Abell 2631 and Abell 2204.Comment: ApJ in pres
Sunyaev Zel'dovich Effect Observations of Strong Lensing Galaxy Clusters: Probing the Over-Concentration Problem
We have measured the Sunyaev Zel'dovich (SZ) effect for a sample of ten
strong lensing selected galaxy clusters using the Sunyaev Zel'dovich Array
(SZA). The SZA is sensitive to structures on spatial scales of a few
arcminutes, while the strong lensing mass modeling constrains the mass at small
scales (typically < 30"). Combining the two provides information about the
projected concentrations of the strong lensing clusters. The Einstein radii we
measure are twice as large as expected given the masses inferred from SZ
scaling relations. A Monte Carlo simulation indicates that a sample randomly
drawn from the expected distribution would have a larger median Einstein radius
than the observed clusters about 3% of the time. The implied overconcentration
has been noted in previous studies with smaller samples of lensing clusters. It
persists for this sample, with the caveat that this could result from a
systematic effect such as if the gas fractions of the strong lensing clusters
are substantially below what is expected.Comment: submitte
LoCuSS: The Sunyaev-Zel'dovich Effect and Weak Lensing Mass Scaling Relation
We present the first weak-lensing-based scaling relation between galaxy
cluster mass, M_wl, and integrated Compton parameter Y_sph. Observations of 18
galaxy clusters at z~0.2 were obtained with the Subaru 8.2-m telescope and the
Sunyaev-Zel'dovich Array. The M_wl-Y_sph scaling relations, measured at
Delta=500, 1000, and 2500 rho_c, are consistent in slope and normalization with
previous results derived under the assumption of hydrostatic equilibrium (HSE).
We find an intrinsic scatter in M_wl at fixed Y_sph of 20%, larger than both
previous measurements of M_HSE-Y_sph scatter as well as the scatter in true
mass at fixed Y_sph found in simulations. Moreover, the scatter in our
lensing-based scaling relations is morphology dependent, with 30-40% larger
M_wl for undisturbed compared to disturbed clusters at the same Y_sph at r_500.
Further examination suggests that the segregation may be explained by the
inability of our spherical lens models to faithfully describe the
three-dimensional structure of the clusters, in particular, the structure along
the line-of-sight. We find that the ellipticity of the brightest cluster
galaxy, a proxy for halo orientation, correlates well with the offset in mass
from the mean scaling relation, which supports this picture. This provides
empirical evidence that line-of-sight projection effects are an important
systematic uncertainty in lensing-based scaling relations.Comment: Accepted versio
Comparison of Pressure Profiles of Massive Relaxed Galaxy Clusters using Sunyaev-Zel'dovich and X-ray Data
We present Sunyaev-Zel'dovich (SZ) effect observations of a sample of 25
massive relaxed galaxy clusters observed with the Sunyaev-Zel'dovich Array
(SZA), an 8-element interferometer that is part of the Combined Array for
Research in Millimeter-wave Astronomy (CARMA). We perform an analysis of new
SZA data and archival Chandra observations of this sample to investigate the
integrated pressure -- a proxy for cluster mass -- determined from X-ray and SZ
observations, two independent probes of the intra-cluster medium. This analysis
makes use of a model for the intra-cluster medium introduced by Bulbul (2010)
which can be applied simultaneously to SZ and X-ray data. With this model, we
estimate the pressure profile for each cluster using a joint analysis of the SZ
and X-ray data, and using the SZ data alone. We find that the integrated
pressures measured from X-ray and SZ data are consistent. This conclusion is in
agreement with recent results obtained using WMAP and Planck data, confirming
that SZ and X-ray observations of massive clusters detect the same amount of
thermal pressure from the intra-cluster medium. To test for possible biases
introduced by our choice of model, we also fit the SZ data using the universal
pressure profile proposed by Arnaud (2010), and find consistency between the
two models out to r500 in the pressure profiles and integrated pressures.Comment: Accepted for New Journal of Physics, Focus Issue on Galaxy Cluster
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