7,798 research outputs found
Understanding Legal Compliance
A Review of Why People Obey the Law by Tom R. Tyle
Paradoxes in Responsibility Attribution: Insights from Law and Social Science
http://deepblue.lib.umich.edu/bitstream/2027.42/50901/1/125.pd
On Measuring a Norm: Should the Punishment Fit the Crime?
http://deepblue.lib.umich.edu/bitstream/2027.42/50950/1/175.pd
Extrasolar Planet Transits Observed at Kitt Peak National Observatory
We obtained J-, H- and JH-band photometry of known extrasolar planet
transiting systems at the 2.1-m Kitt Peak National Observatory Telescope using
the FLAMINGOS infrared camera between October 2008 and October 2011. From the
derived lightcurves we have extracted the mid-transit times, transit depths and
transit durations for these events. The precise mid-transit times obtained help
improve the orbital periods and also constrain transit-time variations of the
systems. For most cases the published system parameters successfully accounted
for our observed lightcurves, but in some instances we derive improved
planetary radii and orbital periods. We complemented our 2.1-m infrared
observations using CCD z'-band and B-band photometry (plus two Hydrogen Alpha
filter observations) obtained with the Kitt Peak Visitor's Center telescope,
and with four H-band transits observed in October 2007 with the NSO's 1.6-m
McMath-Pierce Solar Telescope. The principal highlights of our results are: 1)
our ensemble of J-band planetary radii agree with optical radii, with the
best-fit relation being: (Rp/R*)J = 0.0017 + 0.979 (Rp/R*)optical, 2) We
observe star spot crossings during the transit of WASP-11/HAT-P-10, 3) we
detect star spot crossings by HAT-P-11b (Kepler-3b), thus confirming that the
magnetic evolution of the stellar active regions can be monitored even after
the Kepler mission has ended, and 4) we confirm a grazing transit for
HAT-P-27/WASP-40. In total we present 57 individual transits of 32 known
exoplanet systems.Comment: 33 pages, 6 figures, accepted in Publications of the Astronomical
Society of the Pacifi
Intensity modulated radiation therapy dose painting for localized prostate cancer using(11)C-choline positron emission tomography scans
PURPOSE: To demonstrate the technical feasibility of intensity modulated radiation therapy (IMRT) dose painting using¹¹C-choline positron emission tomography PET scans in patients with localized prostate cancer. METHODS AND MATERIALS: This was an RT planning study of 8 patients with prostate cancer who had ¹¹C-choline PET scans prior to radical prostatectomy. Two contours were semiautomatically generated on the basis of the PET scans for each patient: 60% and 70% of the maximum standardized uptake values (SUV(60%) and SUV(70%)). Three IMRT plans were generated for each patient: PLAN(78), which consisted of whole-prostate radiation therapy to 78 Gy; PLAN(78-90), which consisted of whole-prostate RT to 78 Gy, a boost to the SUV(60%) to 84 Gy, and a further boost to the SUV(70%) to 90 Gy; and PLAN(72-90), which consisted of whole-prostate RT to 72 Gy, a boost to the SUV(60%) to 84 Gy, and a further boost to the SUV(70%) to 90 Gy. The feasibility of these plans was judged by their ability to reach prescription doses while adhering to published dose constraints. Tumor control probabilities based on PET scan-defined volumes (TCP(PET)) and on prostatectomy-defined volumes (TCP(path)), and rectal normal tissue complication probabilities (NTCP) were compared between the plans. RESULTS: All plans for all patients reached prescription doses while adhering to dose constraints. TCP(PET) values for PLAN(78), PLAN(78-90), and PLAN(72-90) were 65%, 97%, and 96%, respectively. TCP(path) values were 71%, 97%, and 89%, respectively. Both PLAN(78-90) and PLAN(72-90) had significantly higher TCP(PET) (P=.002 and .001) and TCP(path) (P<.001 and .014) values than PLAN(78). PLAN(78-90) and PLAN(72-90) were not significantly different in terms of TCP(PET) or TCP(path). There were no significant differences in rectal NTCPs between the 3 plans. CONCLUSIONS: IMRT dose painting for localized prostate cancer using (11)C-choline PET scans is technically feasible. Dose painting results in higher TCPs without higher NTCPs.Joe H. Chang, Daryl Lim Joon, Sze Ting Lee, Sylvia J. Gong, Nigel J. Anderson, Andrew M. Scott, Ian D. Davis, David Clouston, Damien Bolton, Christopher S. Hamilton, Vincent Kho
Topological Phase Diagram of a Two-Subband Electron System
We present a phase diagram for a two-dimensional electron system with two
populated subbands. Using a gated GaAs/AlGaAs single quantum well, we have
mapped out the phases of various quantum Hall states in the density-magnetic
filed plane. The experimental phase diagram shows a very different topology
from the conventional Landau fan diagram. We find regions of negative
differential Hall resistance which are interpreted as preliminary evidence of
the long sought reentrant quantum Hall transitions. We discuss the origins of
the anomalous topology and the negative differential Hall resistance in terms
of the Landau level and subband mixing.Comment: 4 pages, 4 figure
Fitness benefits of prolonged post-reproductive lifespan in women
Most animals reproduce until they die, but in humans, females can survive long after ceasing reproduction. In theory, a prolonged post-reproductive lifespan will evolve when females can gain greater fitness by increasing the success of their offspring than by continuing to breed themselves. Although reproductive success is known to decline in old age, it is unknown whether women gain fitness by prolonging lifespan post-reproduction. Using complete multi-generational demographic records, we show that women with a prolonged post-reproductive lifespan have more grandchildren, and hence greater fitness, in pre-modern populations of both Finns and Canadians. This fitness benefit arises because post-reproductive mothers enhance the lifetime reproductive success of their offspring by allowing them to breed earlier, more frequently and more successfully. Finally, the fitness benefits of prolonged lifespan diminish as the reproductive output of offspring declines. This suggests that in female humans, selection for deferred ageing should wane when one's own offspring become post-reproductive and, correspondingly, we show that rates of female mortality accelerate as their offspring terminate reproduction
Aperture synthesis for gravitational-wave data analysis: Deterministic Sources
Gravitational wave detectors now under construction are sensitive to the
phase of the incident gravitational waves. Correspondingly, the signals from
the different detectors can be combined, in the analysis, to simulate a single
detector of greater amplitude and directional sensitivity: in short, aperture
synthesis. Here we consider the problem of aperture synthesis in the special
case of a search for a source whose waveform is known in detail: \textit{e.g.,}
compact binary inspiral. We derive the likelihood function for joint output of
several detectors as a function of the parameters that describe the signal and
find the optimal matched filter for the detection of the known signal. Our
results allow for the presence of noise that is correlated between the several
detectors. While their derivation is specialized to the case of Gaussian noise
we show that the results obtained are, in fact, appropriate in a well-defined,
information-theoretic sense even when the noise is non-Gaussian in character.
The analysis described here stands in distinction to ``coincidence
analyses'', wherein the data from each of several detectors is studied in
isolation to produce a list of candidate events, which are then compared to
search for coincidences that might indicate common origin in a gravitational
wave signal. We compare these two analyses --- optimal filtering and
coincidence --- in a series of numerical examples, showing that the optimal
filtering analysis always yields a greater detection efficiency for given false
alarm rate, even when the detector noise is strongly non-Gaussian.Comment: 39 pages, 4 figures, submitted to Phys. Rev.
Coexistence of Weak Localization and a Metallic Phase in Si/SiGe Quantum Wells
Magnetoresistivity measurements on p-type Si/SiGe quantum wells reveal the
coexistence of a metallic behavior and weak localization. Deep in the metallic
regime, pronounced weak localization reduces the metallic behavior around zero
magnetic field without destroying it. In the insulating phase, a positive
magnetoresistivity emerges close to B=0, possibly related to spin-orbit
interactions.Comment: 4 pages, 3 figure
Cooler Intensity Limitations
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
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