327 research outputs found
The Tort Revolution: Product Liability and the Rule of Courts
This dissertation is a history of the changes in tort law, specifically in products liability law, from the fault-based negligence standard to the no-fault strict liability standard. It covers a period from the late nineteenth century through the end of the twentieth century. The historical questions this dissertation seeks to answer are i) what caused the change from negligence to strict liability, ii) who were the historical actors responsible for this change, iii) what was the political character of this change, and iv) what were the political consequences of this change.
This dissertation reveals that the revolutionary expansion in product liability law in the states in the 1960s was the product of the Progressive ideologies of state court judges. During the Progressive Era, American legal education responded and adapted to the political climate of the wider society by adopting a new philosophical disposition regarding how the courts should address civil wrongs. The political and ideological responses to the industrialization of the late nineteenth century and early twentieth century resulted in legal academics and practitioners advocating new ideologically oriented theories about how law does and should affect citizens. These theories, known as sociological jurisprudence and legal realism, became popular in American law schools. The law students of the 1920s became the judges and legal academics of the 1950s and 1960s. In the latter decades, Progressive state court judges instituted dramatic, revolutionary changes in the area of law known as torts, particularly products liability law. Products liability law was changed from a fault-based system to an insurance or no-fault system. These politically motivated changes in the courts had the unintended consequence of making a theretofore non-political issue into an inherently political issue, subjecting tort law to the pluralism of the American political system at the state and federal levels. Accordingly, this dissertation contributes to our understanding of the process of legal change, and explores the methods by which social and political changes filter into court decisions
Spitzer/MIPS 24 μm Observations of HD 209458b: Three Eclipses, Two and a Half Transits, and a Phase Curve Corrupted by Instrumental Sensitivity Variations
We report the results of an analysis of all Spitzer/MIPS 24 μm observations of HD 209458b, one of the touchstone objects in the study of irradiated giant planet atmospheres. Altogether, we analyze two and a half transits, three eclipses, and a 58 hr near-continuous observation designed to detect the planet's thermal phase curve. The results of our analysis are: (1) a mean transit depth of 1.484% ± 0.033%, consistent with previous measurements and showing no evidence of variability in transit depth at the 3% level. (2) A mean eclipse depth of 0.338% ± 0.026%, somewhat higher than that previously reported for this system; this new value brings observations into better agreement with models. From this eclipse depth we estimate an average dayside brightness temperature of 1320 ± 80 K; the dayside flux shows no evidence of variability at the 12% level. (3) Eclipses in the system occur 32 ± 129 s earlier than would be expected from a circular orbit, which constrains the orbital quantity ecos ω to be 0.00004 ± 0.00033. This result is fully consistent with a circular orbit and sets an upper limit of 140 m s^(–1) (3σ) on any eccentricity-induced velocity offset during transit. The phase curve observations (including one of the transits) exhibit an anomalous trend similar to the detector ramp seen in previous Spitzer/IRAC observations; by modeling this ramp we recover the system parameters for this transit. The long-duration photometry which follows the ramp and transit exhibits a gradual ~0.2% decrease in flux over ~30 hr. This effect is similar to that seen in pre-launch calibration data taken with the 24 μm array and is better fit by an instrumental model than a model invoking planetary emission. The large uncertainties associated with this poorly understood, likely instrumental effect prevent us from usefully constraining the planet's thermal phase curve. Our observations highlight the need for a thorough understanding of detector-related instrumental effects on long timescales when making the high-precision mid-infrared measurements planned for future missions such as EChO, SPICA, and the James Webb Space Telescope
TITAN Wireless Camera Control System
The Titan Camera Control System is an eletromechanical device that allows the user to wirelessly control a camera’s digital operations as well as physical orientation through the use of a mobile device application. The Titan system accepts input in the form of virtual user commands on the mobile app and performs system output in the form of sending photos/video from the camera back to the app as well as changing the orientation of the camera in accordance with the user’s commands
Constraints on the Atmospheric Circulation and Variability of the Eccentric Hot Jupiter XO-3b
We report secondary eclipse photometry of the hot Jupiter XO-3b in the
4.5~m band taken with the Infrared Array Camera (IRAC) on the Spitzer
Space Telescope. We measure individual eclipse depths and center of eclipse
times for a total of twelve secondary eclipses. We fit these data
simultaneously with two transits observed in the same band in order to obtain a
global best-fit secondary eclipse depth of and a center of
eclipse phase of . We assess the relative magnitude of
variations in the dayside brightness of the planet by measuring the size of the
residuals during ingress and egress from fitting the combined eclipse light
curve with a uniform disk model and place an upper limit of 0.05. The new
secondary eclipse observations extend the total baseline from one and a half
years to nearly three years, allowing us to place an upper limit on the
periastron precession rate of degrees/day the tightest
constraint to date on the periastron precession rate of a hot Jupiter. We use
the new transit observations to calculate improved estimates for the system
properties, including an updated orbital ephemeris. We also use the large
number of secondary eclipses to obtain the most stringent limits to date on the
orbit-to-orbit variability of an eccentric hot Jupiter and demonstrate the
consistency of multiple-epoch Spitzer observations.Comment: 14 pages, 11 figures, published by Ap
The Heating of Test Particles in Numerical Simulations of Alfvenic Turbulence
We study the heating of charged test particles in three-dimensional numerical
simulations of weakly compressible magnetohydrodynamic (MHD) turbulence
(``Alfvenic turbulence''); these results are relevant to particle heating and
acceleration in the solar wind, solar flares, accretion disks onto black holes,
and other astrophysics and heliospheric environments. The physics of particle
heating depends on whether the gyrofrequency of a particle is comparable to the
frequency of a turbulent fluctuation that is resolved on the computational
domain. Particles with these frequencies nearly equal undergo strong
perpendicular heating (relative to the local magnetic field) and pitch angle
scattering. By contrast, particles with large gyrofrequency undergo strong
parallel heating. Simulations with a finite resistivity produce additional
parallel heating due to parallel electric fields in small-scale current sheets.
Many of our results are consistent with linear theory predictions for the
particle heating produced by the Alfven and slow magnetosonic waves that make
up Alfvenic turbulence. However, in contrast to linear theory predictions,
energy exchange is not dominated by discrete resonances between particles and
waves; instead, the resonances are substantially ``broadened.'' We discuss the
implications of our results for solar and astrophysics problems, in particular
the thermodynamics of the near-Earth solar wind. We conclude that Alfvenic
turbulence produces significant parallel heating via the interaction between
particles and magnetic field compressions (``slow waves''). However, on scales
above the proton Larmor radius, Alfvenic turbulence does not produce
significant perpendicular heating of protons or minor ions.Comment: Submitted to Ap
3.6 and 4.5 m Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b
We analyze full-orbit phase curve observations of the transiting hot Jupiters
WASP-19b and HAT-P-7b at 3.6 and 4.5 m obtained using the Spitzer Space
Telescope. For WASP-19b, we measure secondary eclipse depths of and at 3.6 and 4.5 m, which are consistent
with a single blackbody with effective temperature K. The
measured 3.6 and 4.5 m secondary eclipse depths for HAT-P-7b are
and , which are well-described by a
single blackbody with effective temperature K. Comparing the phase
curves to the predictions of one-dimensional and three-dimensional atmospheric
models, we find that WASP-19b's dayside emission is consistent with a model
atmosphere with no dayside thermal inversion and moderately efficient day-night
circulation. We also detect an eastward-shifted hotspot, suggesting the
presence of a superrotating equatorial jet. In contrast, HAT-P-7b's dayside
emission suggests a dayside thermal inversion and relatively inefficient
day-night circulation; no hotspot shift is detected. For both planets, these
same models do not agree with the measured nightside emission. The
discrepancies in the model-data comparisons for WASP-19b might be explained by
high-altitude silicate clouds on the nightside and/or high atmospheric
metallicity, while the very low 3.6 m nightside planetary brightness for
HAT-P-7b may be indicative of an enhanced global C/O ratio. We compute Bond
albedos of 0 ( at ) and for WASP-19b and
HAT-P-7b, respectively. In the context of other planets with thermal phase
curve measurements, we show that WASP-19b and HAT-P-7b fit the general trend of
decreasing day-night heat recirculation with increasing irradiation.Comment: 22 pages, 29 figures, accepted by Ap
Optical to near-infrared transmission spectrum of the warm sub-Saturn HAT-P-12b
We present the transmission spectrum of HAT-P-12b through a joint analysis of
data obtained from the Hubble Space Telescope Space Telescope Imaging
Spectrograph (STIS) and Wide Field Camera 3 (WFC3) and Spitzer, covering the
wavelength range 0.3-5.0 m. We detect a muted water vapor absorption
feature at 1.4 m attenuated by clouds, as well as a Rayleigh scattering
slope in the optical indicative of small particles. We interpret the
transmission spectrum using both the state-of-the-art atmospheric retrieval
code SCARLET and the aerosol microphysics model CARMA. These models indicate
that the atmosphere of HAT-P-12b is consistent with a broad range of
metallicities between several tens to a few hundred times solar, a roughly
solar C/O ratio, and moderately efficient vertical mixing. Cloud models that
include condensate clouds do not readily generate the sub-micron particles
necessary to reproduce the observed Rayleigh scattering slope, while models
that incorporate photochemical hazes composed of soot or tholins are able to
match the full transmission spectrum. From a complementary analysis of
secondary eclipses by Spitzer, we obtain measured depths of
and at 3.6 and 4.5 m, respectively, which are
consistent with a blackbody temperature of K and indicate
efficient day-night heat recirculation. HAT-P-12b joins the growing number of
well-characterized warm planets that underscore the importance of clouds and
hazes in our understanding of exoplanet atmospheres.Comment: 25 pages, 19 figures, accepted for publication in AJ, updated with
proof correction
Inflammation in benign prostate tissue and prostate cancer in the finasteride arm of the Prostate Cancer Prevention Trial
BACKGROUND: A previous analysis of the placebo arm of the Prostate Cancer Prevention Trial (PCPT) reported 82% overall prevalence of intraprostatic inflammation and identified a link between inflammation and higher-grade prostate cancer and serum PSA. Here we studied these associations in the PCPT finasteride arm. METHODS: Prostate cancer cases (N=197) detected either on a clinically indicated biopsy or on protocol-directed end-of-study biopsy, and frequency-matched controls (N=248) with no cancer on an end-of-study biopsy were sampled from the finasteride arm. Inflammation in benign prostate tissue was visually assessed using digital images of H&E stained sections. Logistic regression was used for statistical analysis. RESULTS: In the finasteride arm, 91.6% of prostate cancer cases and 92.4% of controls had at least one biopsy core with inflammation in benign areas; p < 0.001 for difference compared to placebo arm. Overall, the odds of prostate cancer did not differ by prevalence (OR=0.90, 95% CI 0.44-1.84) or extent (P-trend=0.68) of inflammation. Inflammation was not associated with higher-grade disease (prevalence: OR=1.07, 95% CI 0.43-2.69). Furthermore, mean PSA concentration did not differ by the prevalence or extent of inflammationin either cases or controls. CONCLUSION: The prevalence of intraprostatic inflammation was higher in the finasteride than placebo arm of the PCPT, with no association with higher-grade prostate cancer. IMPACT: Finasteride may attenuate the association between inflammation and higher-grade prostate cancer. Moreover, the missing link between intraprostatic inflammation and PSA suggests that finasteride may reduce inflammation-associated PSA elevation
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