410 research outputs found
A Study Abroad Program in Tanzania: The Evolution of Social Justice Action Work
This article focuses on the evolution of our study abroad program to Tanzania, including the integration of three liberal arts disciplines and the foundational core that links together the three areas: social justice activism. More specifically, we explore the overall challenge of dismantling “us versus them” thinking and the interactive learning moments that allow this process to transpire. We narrate how what we learned on our 2008 and our 2010 trips led to our model of social justice action work, which we enacted on our 2012 trip. Our approach to social justice action work integrates experiential learning with Dan Butin’s concept of “justice learning,” or education that interrupts and complicates binary thinking. Our three-fold model encompasses teaching moments where instructors create the academic framework to facilitate change in our students, where students observe grass-roots organizations performing “traditional” social justice action work, and where on-site activities generate interactive experiential moments in which perceptions can be changed
Identifying galaxy candidates in WSRT HI imaging of ultra-compact high velocity clouds
Ultra-compact high velocity clouds (UCHVCs) were identified in the ALFALFA HI
survey as potential gas-bearing dark matter halos. Here we present higher
resolution neutral hydrogen (HI) observations of twelve UCHVCS with the
Westerbork Synthesis Radio Telescope (WSRT). The UCHVCs were selected based on
a combination of size, isolation, large recessional velocity and high column
density as the best candidate dark matter halos. The WSRT data were tapered to
image the UCHVCs at 210" (comparable to Arecibo) and 105" angular resolution.
In a comparison of the single-dish to interferometer data, we find that the
line flux recovered in the WSRT observations is comparable to that from the
single-dish ALFALFA data. In addition, any structure seen in the ALFALFA data
is reproduced in the WSRT maps at the same angular resolution. At 210'"
resolution all the sources are generally compact with a smooth HI morphology,
as expected from their identification as UCHVCs. At the higher angular
resolution, a majority of the sources break into small clumps contained in a
diffuse envelope. These UCHVCs also have no ordered velocity motion and are
most likely Galactic halo clouds. We identify two UCHVCs, AGC 198606 and AGC
249525, as excellent galaxy candidates based on maintaining a smooth HI
morphology at higher angular resolution and showing ordered velocity motion
consistent with rotation. A third source, AGC 249565, lies between these two
populations in properties and is a possible galaxy candidate. If interpreted as
gas-bearing dark matter halos, the three candidate galaxies have rotation
velocities of 8-15 km/s, HI masses of 0.6-50 x 10^5 Msun, HI radii of 0.3-2
kpc, and dynamical masses of 2-20 x 10^7 Msun for a range of plausible
distances. These are the UCHVCs with the highest column density values in the
ALFALFA HI data and we suggest this is the best way to identify further
candidates.Comment: Accepted for publication in A&A. 26 pages, 19 figures, 5 table
Detection of an Optical Counterpart to the ALFALFA Ultra-compact High Velocity Cloud AGC 249525
We report on the detection at 98% confidence of an optical counterpart to
AGC 249525, an Ultra-Compact High Velocity Cloud (UCHVC) discovered by the
ALFALFA blind neutral hydrogen survey. UCHVCs are compact, isolated HI clouds
with properties consistent with their being nearby low-mass galaxies, but
without identified counterparts in extant optical surveys. Analysis of the
resolved stellar sources in deep - and -band imaging from the WIYN pODI
camera reveals a clustering of possible Red Giant Branch stars associated with
AGC 249525 at a distance of 1.640.45 Mpc. Matching our optical detection
with the HI synthesis map of AGC 249525 from Adams et al. (2016) shows that the
stellar overdensity is exactly coincident with the highest-density HI contour
from that study. Combining our optical photometry and the HI properties of this
object yields an absolute magnitude of , a stellar
mass between and , and an HI to stellar mass ratio between 9 and 144. This object has
stellar properties within the observed range of gas-poor Ultra-Faint Dwarfs in
the Local Group, but is gas-dominated.Comment: 9 pages, 4 figures; accepted to ApJ
The Atlántida of Capitalism. The murals of Sert in the decorative programme of New York’s Rockefeller Center
New York’s Rockefeller Center is one of most symbolically rich places in the world, although few of its millions of visitors stop to reflect on what its images of power really mean. In the form of an Atlantean mythological allegory, Rockefeller Center was conceived as symbolic propaganda for capitalist, liberal values implicit in both the ‘American Dream’ and the ideology espoused by the Rockefeller family. It embodies the utopia of progress and science that promotes the freedom of the individual and the free movement of capital. Due to ideological clashes –or the vagaries of fate– the Catalan José María Sert was the artist to ultimately complete the most eloquent mural in the main building, a mural which had formerly been painted by Diego de Rivera, and entitled Man at the Crossroads. Sert was a muralist who had previously worked on the scenographic illustration of Manuel de Falla’s Atlántida, capturing some of the motifs that inspired that great cantata based on poetic texts by Jacint Verdaguer. That earlier work is reflected in the lobby of Rockefeller Center’s main building. While Diego de Rivera’s censored frescoes have been studied prolifically, little attention has been paid to Sert’s paradoxical reading of the same subjects. In this article, we analyse the history of the Atlantean Mediterranean literary myth in relation to Spain, the use John D. Rockefeller Jr. made of them in his emblematic urbanistic ensemble, and also the peculiar reading that the Catalan muralist made of these themes of Atlantis in relation to capitalism
Use of a Multi-Reference GPS Station Network for Precise 3D Positioning in Constricted Waterways
Numerous coastal and inland marine operations, including navigation in shallow constricted waterways require time-consuming and expensive maintenance that includes frequent precise multi-beam hydrographic surveys and dredging operations. In addition, environmental and safety concerns lead to the establishment of stringent regulations regarding the minimum under keel clearance for commercial shipping operations. The clearance is partly a function of the navigation channel charting accuracy and the ability to determine the instantaneous water level in real time. The use of real-time kinematic (RTK) GPS to provide a three-dimensional accuracy of better than 10 cm has the potential to improve the effectiveness of channel maintenance and commercial navigation. In order for RTK GPS to yield such a high level of accuracy, carrier phase observables must be used. One of the most important limitations is the requirement for short distances between the ship and shore-based fixed reference stations. With the current GPS capability, the distance should be kept to less than 15 to 20 km to assure a continuous service. Establishing reference stations with such a high density is time-consuming, logistically difficult and results in high maintaining cost and operational reliability issues. In this paper a method to substantially reduce the number of reference stations is investigated through field trials conducted along the St. Lawrence Seaway, Canada, in 1998 and 1999. The proximity of the trials to a solar maximum resulted in a very high level of atmospheric activity and provided an opportunity to examine the advantages and limitations of both the conventional and multi-reference station RTK methods under such conditions. The results of the trials show that the new approach results in a substantial improvement of up to 60%
Introducing the Remote Mentoring of Undergraduate Research Students (ReMentURS) Workshop Series: Initial Evaluation and Plans for Wider Implementation
The primary objective of the Remote Mentoring of Undergraduate Research Students (ReMentURS) workshop series is to design a remotely available professional development training that will provide rigorous research concept and skills introduction to incoming undergraduate research students. This pilot run eight-week remote learning workshop series includes digital presentations, informational videos, virtual demonstrations, and aligned comprehension checks to foster student mindsets towards becoming independent research scientists. Preliminary assessment of the of ReMentURS program reveals that participants self-report gaining a variety of skills through the series and are likely to use the content in their future course and research laboratories. ReMentURS material can be shared with any undergraduate student who is interested in joining a research group to familiarize them with basic research techniques. Student learning gains will continue to be evaluated throughout the series and this initial assessment will be used towards the betterment of the future workshops
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