1,788 research outputs found
Rediscovering Congressional Intelligence Oversight: Is Another Church Committee Possible Without Frank Church?
This Article compares a historical model of congressional intelligence oversight, as demonstrated by Church’s leadership as chairman of the U.S. Senate Select Committee to Study Governmental Operations with Respect to Intelligence Activities (“Church Committee”), with current intelligence oversight deficiencies that have induced a growing population of citizens to demand greater protections against government overreach and wrongdoing. By examining the difficulties Church and the Church Committee experienced in gathering evidence of government misconduct and publicly disseminating such information, a more historical perspective may reveal the viability of alternative methods of congressional intelligence oversight
Behavior of Euphorbia Heterophylla Seed Bank.
Short term burial of freshly harvested seed and soil disturbances in agricultural populations of wild poinsettia (Euphorbia heterophylla L.) indicated a very low carry over of seeds into the second season after dissemination. After seeds were buried at 10, 50, 100, and 200 mm in the fall; 4%, 81%, 30% and 1%, respectively, produced seedlings during the following growing season, and only 3%, 1%, \u3c 1%, and 3% of the seeds, respectively, were viable after one year. Soil disturbances (tillage) did not affect seedling recruitment or longevity of wild poinsettia seed. Early planting dates (May 1) of soybeans required 6 weeks of weed-free maintenance to prevent serious reinfestation and subsequent yield reductions in fields with a high agronomic seed bank of wild poinsettia, whereas for late planting dates (June 10) 3 weeks of weed-free maintenance was required. No significant difference in yield was detected between one or two cultivations for either planting date
Microwave ISM Emission in the Green Bank Galactic Plane Survey: Evidence for Spinning Dust
We observe significant dust-correlated emission outside of H II regions in
the Green Bank Galactic Plane Survey (-4 < b < 4 degrees) at 8.35 and 14.35
GHz. The rising spectral slope rules out synchrotron and free-free emission as
majority constituents at 14 GHz, and the amplitude is at least 500 times higher
than expected thermal dust emission. When combined with the Rhodes (2.326 GHz),
and WMAP (23-94 GHz) data it is possible to fit dust-correlated emission at
2.3-94 GHz with only soft synchrotron, free-free, thermal dust, and an
additional dust-correlated component similar to Draine & Lazarian spinning
dust. The rising component generally dominates free-free and synchrotron for
\nu >~ 14 GHz and is overwhelmed by thermal dust at \nu > 60 GHz. The current
data fulfill most of the criteria laid out by Finkbeiner et al. (2002) for
detection of spinning dust.Comment: ApJ in press. 26 pages, 11 figures, figures jpeg compressed to save
spac
Pulsar Science with the Green Bank 43m Telescope
The 43m telescope at the NRAO site in Green Bank, WV has recently been
outfitted with a clone of the Green Bank Ultimate Pulsar Processing Instrument
(GUPPI \cite{Ransom:2009}) backend, making it very useful for a number of
pulsar related studies in frequency ranges 800-1600 MHz and 220-440 MHz. Some
of the recent science being done with it include: monitoring of the Crab
pulsar, a blind search for transient sources, pulsar searches of targets of
opportunity, and an all-sky mapping project. For the Crab monitoring project,
regular observations are searched for giant pulses (GPs), which are then
correlated with -ray photons from the \emph{Fermi} spacecraft. Data
from the all-sky mapping project are first run through a pipeline that does a
blind transient search, looking for single pulses over a DM range of 0-500
pc~cm. These projects are made possible by MIT Lincoln Labs.Comment: 2 pages, 1 figure, to appear in AIP Conference Proceedings of Pulsar
Conference 2010 "Radio Pulsars: a key to unlock the secrets of the Universe",
Sardinia, October 201
A Giant Sample of Giant Pulses from the Crab Pulsar
We observed the Crab pulsar with the 43-m telescope in Green Bank, WV over a
timespan of 15 months. In total we obtained 100 hours of data at 1.2 GHz and
seven hours at 330 MHz, resulting in a sample of about 95000 giant pulses
(GPs). This is the largest sample, to date, of GPs from the Crab pulsar taken
with the same telescope and backend and analyzed as one data set. We calculated
power-law fits to amplitude distributions for main pulse (MP) and interpulse
(IP) GPs, resulting in indices in the range of 2.1-3.1 for MP GPs at 1.2 GHz
and in the range of 2.5-3.0 and 2.4-3.1 for MP and IP GPs at 330 MHz. We also
correlated the GPs at 1.2 GHz with GPs from the Robert C. Byrd Green Bank
Telescope (GBT), which were obtained simultaneously at a higher frequency (8.9
GHz) over a span of 26 hours. In total, 7933 GPs from the 43-m telescope at 1.2
GHz and 39900 GPs from the GBT were recorded during these contemporaneous
observations. At 1.2 GHz, 236 (3%) MP GPs and 23 (5%) IP GPs were detected at
8.9 GHz, both with zero chance probability. Another 15 (4%) low-frequency IP
GPs were detected within one spin period of high-frequency IP GPs, with a
chance probability of 9%. This indicates that the emission processes at high
and low radio frequencies are related, despite significant pulse profile shape
differences. The 43-m GPs were also correlated with Fermi gamma-ray photons to
see if increased pair production in the magnetosphere is the mechanism
responsible for GP emission. A total of 92022 GPs and 393 gamma-ray photons
were used in this correlation analysis. No significant correlations were found
between GPs and gamma-ray photons. This indicates that increased pair
production in the magnetosphere is likely not the dominant cause of GPs.
Possible methods of GP production may be increased coherence of synchrotron
emission or changes in beaming direction.Comment: 33 pages, 10 figures, 6 tables, accepted for publication in Ap
The Guilded Classroom: Using Gamification to Engage and Motivate Undergraduates
There is a breadth of psychological research that points to potential cognitive benefits of game play. Games engage and motivate learners while promoting mastery of skills and content knowledge. Further, thoughtfully applying gaming elements and structures to classroom environments, an approach called gamification, has the potential to optimize learning. This paper discusses theory-driven classroom gamification innovations implemented in an undergraduate educational psychology course and uses a case study approach to understand how these changes impacted students’ in-class learning experiences in positive ways. We will discuss specific interventions, students’ perceptions of these interventions, instructor reflection of the effects on student learning outcomes, and implications for classroom practice.
Receptor for advanced glycation endproducts (RAGE) deficiency protects against MPTP toxicity
Copyright © 2011 Elsevier Inc. All rights reserved.Peer reviewedPublisher PD
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