756 research outputs found
Alternatives, Adoption, and Administrative Hearings: Keys to Performing Environmental Reviews for Yucca Mountain
With Liberty and Environmental Justice for All: A Decade at the Nuclear Regulatory Commission
Role of delay in the stochastic creation process
We develop an approximate theoretical method to study discrete stochastic
birth and death models that include a delay time. We analyze the effect of the
delay in the fluctuations of the system and obtain that it can qualitatively
alter them. We also study the effect of distributed delay. We apply the method
to a protein-dynamics model that explicitly includes transcription and
translation delays. The theoretical model allows us to understand in a general
way the interplay between stochasticity and delay
Gravity Spy: Integrating Advanced LIGO Detector Characterization, Machine Learning, and Citizen Science
(abridged for arXiv) With the first direct detection of gravitational waves,
the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) has
initiated a new field of astronomy by providing an alternate means of sensing
the universe. The extreme sensitivity required to make such detections is
achieved through exquisite isolation of all sensitive components of LIGO from
non-gravitational-wave disturbances. Nonetheless, LIGO is still susceptible to
a variety of instrumental and environmental sources of noise that contaminate
the data. Of particular concern are noise features known as glitches, which are
transient and non-Gaussian in their nature, and occur at a high enough rate so
that accidental coincidence between the two LIGO detectors is non-negligible.
In this paper we describe an innovative project that combines crowdsourcing
with machine learning to aid in the challenging task of categorizing all of the
glitches recorded by the LIGO detectors. Through the Zooniverse platform, we
engage and recruit volunteers from the public to categorize images of glitches
into pre-identified morphological classes and to discover new classes that
appear as the detectors evolve. In addition, machine learning algorithms are
used to categorize images after being trained on human-classified examples of
the morphological classes. Leveraging the strengths of both classification
methods, we create a combined method with the aim of improving the efficiency
and accuracy of each individual classifier. The resulting classification and
characterization should help LIGO scientists to identify causes of glitches and
subsequently eliminate them from the data or the detector entirely, thereby
improving the rate and accuracy of gravitational-wave observations. We
demonstrate these methods using a small subset of data from LIGO's first
observing run.Comment: 27 pages, 8 figures, 1 tabl
The Deep Lens Survey Transient Search I : Short Timescale and Astrometric Variability
We report on the methodology and first results from the Deep Lens Survey
transient search. We utilize image subtraction on survey data to yield all
sources of optical variability down to 24th magnitude. Images are analyzed
immediately after acquisition, at the telescope and in near-real time, to allow
for followup in the case of time-critical events. All classes of transients are
posted to the web upon detection. Our observing strategy allows sensitivity to
variability over several decades in timescale. The DLS is the first survey to
classify and report all types of photometric and astrometric variability
detected, including solar system objects, variable stars, supernovae, and short
timescale phenomena. Three unusual optical transient events were detected,
flaring on thousand-second timescales. All three events were seen in the B
passband, suggesting blue color indices for the phenomena. One event (OT
20020115) is determined to be from a flaring Galactic dwarf star of spectral
type dM4. From the remaining two events, we find an overall rate of \eta = 1.4
events deg-2 day-1 on thousand-second timescales, with a 95% confidence limit
of \eta < 4.3. One of these events (OT 20010326) originated from a compact
precursor in the field of galaxy cluster Abell 1836, and its nature is
uncertain. For the second (OT 20030305) we find strong evidence for an extended
extragalactic host. A dearth of such events in the R passband yields an upper
95% confidence limit on short timescale astronomical variability between 19.5 <
R < 23.4 of \eta_R < 5.2. We report also on our ensemble of astrometrically
variable objects, as well as an example of photometric variability with an
undetected precursor.Comment: 24 pages, 12 figures, 3 tables. Accepted for publication in ApJ.
Variability data available at http://dls.bell-labs.com/transients.htm
LoCuSS: First Results from Strong-lensing Analysis of 20 Massive Galaxy Clusters at z~0.2
We present a statistical analysis of a sample of 20 strong lensing clusters
drawn from the Local Cluster Substructure Survey (LoCuSS), based on high
resolution Hubble Space Telescope imaging of the cluster cores and follow-up
spectroscopic observations using the Keck-I telescope. We use detailed
parameterized models of the mass distribution in the cluster cores, to measure
the total cluster mass and fraction of that mass associated with substructures
within R<250kpc.These measurements are compared with the distribution of
baryons in the cores, as traced by the old stellar populations and the X-ray
emitting intracluster medium. Our main results include: (i) the distribution of
Einstein radii is log-normal, with a peak and 1sigma width of
=1.16+/-0.28; (ii) we detect an X-ray/lensing mass discrepancy of
=1.3 at 3 sigma significance -- clusters with larger substructure
fractions displaying greater mass discrepancies, and thus greater departures
from hydrostatic equilibrium; (iii) cluster substructure fraction is also
correlated with the slope of the gas density profile on small scales, implying
a connection between cluster-cluster mergers and gas cooling. Overall our
results are consistent with the view that cluster-cluster mergers play a
prominent role in shaping the properties of cluster cores, in particular
causing departures from hydrostatic equilibrium, and possibly disturbing cool
cores. Our results do not support recent claims that large Einstein radius
clusters present a challenge to the CDM paradigm.Comment: 28 pages, 14 figures, accepted for publication in MNRAS, replaced
with accepted versio
The changing of the guard: groupwork with people who have intellectual disabilities
This paper considers the impact of service systems on group activities. It describes an inter-professional groupwork project facilitated by a social worker and a community nurse. The project provided an emancipatory experience for a group of adults who had intellectual disabilities. The group was charged with the task of reviewing and updating the recruitment and interview processes used by a 'Learning Disability Partnership Board', when employing new support workers.
The paper begins with a brief history of intellectual disability and provides a context to the underpinning philosophical belief that people should be encouraged and supported to inhabit valued social roles no matter what disability they may have. It then identifies the ways in which the sponsoring health, education and social care services impacted on the creation and development of a groupwork project. It might have been expected that the nature of the intellectual disability would have been the major influence on group process. However the paper reveals that organisational constraints had a significant impact on group functioning. Issues including, staffing budgets and transport contracts impacted on group process and function.
The results of the project show how, with adequate support, people with intellectual disability can make important decisions that have long-reaching impacts on the services
Evolutionary Ecology of Prokaryotic Immune Mechanisms.
Published onlineJournal ArticleReviewBacteria have a range of distinct immune strategies that provide protection against bacteriophage (phage) infections. While much has been learned about the mechanism of action of these defense strategies, it is less clear why such diversity in defense strategies has evolved. In this review, we discuss the short- and long-term costs and benefits of the different resistance strategies and, hence, the ecological conditions that are likely to favor the different strategies alone and in combination. Finally, we discuss some of the broader consequences, beyond resistance to phage and other genetic elements, resulting from the operation of different immune strategies.S.V.H. received funding from the European Union's Horizon 2020 research and innovation program under Marie SkĆodowska-Curie grant agreement no. 660039. We also acknowledge the NERC, the BBSRC, the Royal Society, the Leverhulme Trust, the Wellcome Trust, and the AXA research fund for funding
- âŠ