12,112 research outputs found
The Dilemma of Direct Democracy
The dilemma of direct democracy is that voters may not always be able to make welfare- improving decisions. Lupia’s seminal work has led us to believe that voters can substitute voting cues for substantive policy knowledge. Lupia, however, emphasized that cues were valuable under certain conditions and not others. In what follows, we present three main findings regarding voters and what they know about California’s Proposition 7. First, much like Lupia reported, we show voters who are able to recall endorsements for or against a ballot measure vote similarly to people who recall certain basic facts about the initiative. We show, second, that voters whose stated policy preferences would otherwise suggest they would favor the “no” position cast their ballots with far less error than do people who favor the “yes” position. One thing this suggests is that many voters may employ a “defensive no” strategy when faced with complex policy choices on the ballot. Our third result is a bit surprising: we find that better- informed voters, whether this information is derived from factual knowledge of the initiative or from knowledge of well-publicized voting cues, are no more likely to make reasoned decisions than those who are, by our measure, uninformed. This suggests that existing theories of voter choice, especially in direct democracy, may be inadequate. We conclude with some preliminary policy recommendations that could help improve the information environment for initiatives and referenda by providing key information on the ballot
Values of H_0 from Models of the Gravitational Lens 0957+561
The lensed double QSO 0957+561 has a well-measured time delay and hence is
useful for a global determination of H0. Uncertainty in the mass distribution
of the lens is the largest source of uncertainty in the derived H0. We
investigate the range of \hn produced by a set of lens models intended to mimic
the full range of astrophysically plausible mass distributions, using as
constraints the numerous multiply-imaged sources which have been detected. We
obtain the first adequate fit to all the observations, but only if we include
effects from the galaxy cluster beyond a constant local magnification and
shear. Both the lens galaxy and the surrounding cluster must depart from
circular symmetry as well.
Lens models which are consistent with observations to 95% CL indicate
H0=104^{+31}_{-23}(1-\kthirty) km/s/Mpc. Previous weak lensing measurements
constrain the mean mass density within 30" of G1 to be kthirty=0.26+/-0.16 (95%
CL), implying H0=77^{+29}_{-24}km/s/Mpc (95% CL). The best-fitting models span
the range 65--80 km/s/Mpc. Further observations will shrink the confidence
interval for both the mass model and \kthirty.
The range of H0 allowed by the full gamut of our lens models is substantially
larger than that implied by limiting consideration to simple power law density
profiles. We therefore caution against use of simple isothermal or power-law
mass models in the derivation of H0 from other time-delay systems. High-S/N
imaging of multiple or extended lensed features will greatly reduce the H0
uncertainties when fitting complex models to time-delay lenses.Comment: AASTEX, 48 pages 4 figures, 2 tables. Also available at:
http://www.astro.lsa.umich.edu:80/users/philf/www/papers/list.htm
Social and Economic Impact of Solar Electricity at Schuchuli Village
Schuchuli, a small remote village on the Papago Indian Reservation in southwest Arizona, is 27 kilometers (17 miles) from the nearest available utility power. Its lack of conventional power is due to the prohibitive cost of supplying a small electrical load with a long-distance distribution line. Furthermore, alternate energy sources are expensive and place a burden on the resources of the villagers. On December 16, 1978, as part of a federally funded project, a solar cell power system was put into operation at Schuchuli. The system powers the village water pump, lighting for homes and other village buildings, family refrigerators and a communal washing machine and sewing machine
Ambitious STS-7 mission to feature first landing at Kennedy
The STS-7 press briefing schedule, NASA select television schedule; launch preparations, countdown and liftoff; major countdown milestones; launch window; STS-7 flight sequence of events, landing timeline; STS-7 flight timeline; landing and post landing operations; flight objectives; Telesat's ANIK-C 2; PALAPA-B; STS-7 experiments; and spacecraft tracking and data network are presented
Chandra Observations of the Gravitationally Lensed System 2016+112
An observation of the gravitationally lensed system 2016+112 with the Chandra
X-ray Observatory has resolved a mystery regarding the proposed presence of a
dark matter object in the lens plane of this system. The Chandra ACIS
observation has clearly detected the lensed images of 2016+112 with positions
in good agreement with those reported in the optical and also detects 13
additional X-ray sources within a radius of 3.5 arcmin. Previous X-ray
observations in the direction of 2016+112 with the ROSAT HRI and ASCA SIS have
interpreted the X-ray data as arising from extended emission from a dark
cluster. However, the present Chandra observation can account for all the X-ray
emission as originating from the lensed images and additional point X-ray
sources in the field. Thus cluster parameters based on previous X-ray
observations are unreliable. We estimate an upper limit on the mass-to-light
ratio within a radius of 800 h_(50)^(-1) kpc of M/L_(V) < 190 h_(50)
(M/L_(V))_Sun. The lensed object is quite unusual, with reported narrow
emission lines in the optical that suggest it may be a type-2 quasar (Yamada
et. al. 1999). Our modeling of the X-ray spectrum of the lensed object implies
that the column density of an intrinsic absorber must lie between 3 and 85 x
10^22 cm^-2 (3 sigma confidence level). The 2-10 keV luminosity of the lensed
object, corrected for the lens magnification effect and using the above range
of intrinsic absorption, is 3 x 10^43 - 1.4 x 10^44 erg/s.Comment: 9 pages, includes 2 figures, Accepted for publication in ApJ
Cluster Cores, Gravitational Lensing, and Cosmology
Many multiply--imaged quasars have been found over the years, but none so far
with image separation in excess of 8\arcsec. The absence of such large
splittings has been used as a test of cosmological models: the standard Cold
Dark Matter model has been excluded on the basis that it predicts far too many
large--separation double images. These studies assume that the lensing
structure has the mass profile of a singular isothermal sphere. However, such
large splittings would be produced by very massive systems such as clusters of
galaxies, for which other gravitational lensing data suggest less singular mass
profiles. Here we analyze two cases of mass profiles for lenses: an isothermal
sphere with a finite core radius (density , and a Hernquist profile (). We find that small core radii
kpc, as suggested by the cluster data, or large a \gsim 300 h^{-1} kpc, as
needed for compatibility with gravitational distortion data, would reduce the
number of large--angle splittings by an order of magnitude or more. Thus, it
appears that these tests are sensitive both to the cosmological model (number
density of lenses) and to the inner lens structure, which is unlikely to depend
sensitively on the cosmology, making it difficult to test the cosmological
models by large--separation quasar lensing until we reliably know the structure
of the lenses themselves.Comment: 17 pages, uuencoded compressed tarred postscript file including text
and 1 figure. To appear in January 20, 1996 issue of ApJ Letter
Hybridization gap versus hidden order gap in URuSi as revealed by optical spectroscopy
We present the in-plane optical reflectance measurement on single crystals of
URuAs. The study revealed a strong temperature-dependent spectral
evolution. Above 50 K, the low frequency optical conductivity is rather flat
without a clear Drude-like response, indicating a very short transport life
time of the free carriers. Well below the coherence temperature, there appears
an abrupt spectral weight suppression below 400 cm, yielding evidence
for the formation of a hybridization energy gap arising from the mixing of the
conduction electron and narrow f-electron bands. A small part of the suppressed
spectral weight was transferred to the low frequency side, leading to a narrow
Drude component, while the majority of the suppressed spectral weight was
transferred to the high frequency side centered near 4000 cm. Below the
hidden order temperature, another very prominent energy gap structure was
observed, which leads to the removal of a large part of the Drude component and
a sharp reduction of the carrier scattering rate. The study revealed that the
hybridization gap and the hidden orger gap are distinctly different: they occur
at different energy scales and exhibit completely different spectral
characteristics.Comment: 5 page
Development of an integrated cognitive behavioral therapy for anxiety and opioid use disorder: Study protocol and methods
Opioid use disorder is a highly disabling psychiatric disorder, and is associated with both significant functional disruption and risk for negative health outcomes such as infectious disease and fatal overdose. Even among those who receive evidence-based pharmacotherapy for opioid use disorder, many drop out of treatment or relapse, highlighting the importance of novel treatment strategies for this population. Over 60% of those with opioid use disorder also meet diagnostic criteria for an anxiety disorder; however, efficacious treatments for this common co-occurrence have not be established. This manuscript describes the rationale and methods for a behavioral treatment development study designed to develop and test an integrated cognitive-behavioral therapy for those with co-occurring opioid use disorder and anxiety disorders. The aims of the study are (1) to develop and pilot test a new manualized cognitive behavioral therapy for co-occurring opioid use disorder and anxiety disorders, (2) to test the efficacy of this treatment relative to an active comparison treatment that targets opioid use disorder alone, and (3) to investigate the role of stress reactivity in both prognosis and recovery from opioid use disorder and anxiety disorders. Our overarching aim is to investigate whether this new treatment improves both anxiety and opioid use disorder outcomes relative to standard treatment. Identifying optimal treatment strategies for this population are needed to improve outcomes among those with this highly disabling and life-threatening disorder.This study was funded by NIDA grant DA035297. The funding source had no involvement in the study design, analysis and interpretation of data, writing of the report, or the decision to submit the article for publication. (DA035297 - NIDA)Accepted manuscrip
An investigation into the feasibility of myoglobin-based single-electron transistors
Myoglobin single-electron transistors were investigated using nanometer- gap
platinum electrodes fabricated by electromigration at cryogenic temperatures.
Apomyoglobin (myoglobin without heme group) was used as a reference. The
results suggest single electron transport is mediated by resonant tunneling
with the electronic and vibrational levels of the heme group in a single
protein. They also represent a proof-of-principle that proteins with redox
centers across nanometer-gap electrodes can be utilized to fabricate
single-electron transistors. The protein orientation and conformation may
significantly affect the conductance of these devices. Future improvements in
device reproducibility and yield will require control of these factors
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