3,908 research outputs found
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Off the record?: Arrestee concerns about the manipulation, modification, and misrepresentation of police body-worn camera footage
Police body-worn cameras (BWC) have become the latest technological device introduced to policing on a wave of panacean promises. Recent research has reported the perspectives of police officers, police management, and the general public, but there have been no studies examining the views of police arrestees. Remedying this significant omission, this article presents findings generated from interviews with 907 individuals shortly after their arrest. Overall, we report a strong in principle support for police body-worn cameras amongst this cohort, particularly if the cameras can be operated impartially. The findings are organised into a trilogy of prominent and interrelated concerns voiced by the police detainees, namely the potential for the manipulation, modification, and misrepresentation of events captured by police body-worn cameras. The findings are discussed in a broader context of the ânew visibilityâ of police encounters and contribute much needed findings to understand the culturally specific ways in which different publics experience and respond to visual surveillance
ALPyNA: Acceleration of Loops in Python for Novel Architectures
We present ALPyNA, an automatic loop parallelization framework for Python, which analyzes data dependences within nested loops and dynamically generates CUDA kernels for GPU execution. The ALPyNA system applies classical dependence analysis techniques to discover and exploit potential parallelism. The skeletal structure of the dependence graph is determined statically (if possible) or at runtime; this is combined with type and bounds information discovered at runtime, to auto-generate high-performance kernels for offload to GPU.
We demonstrate speedups of up to 1000x relative to the native CPython interpreter across four array-intensive numerical Python benchmarks. Performance improvement is related to both iteration domain size and dependence graph complexity. Nevertheless, this approach promises to bring the benefits of manycore parallelism to application developers
The Revised TESS Input Catalog and Candidate Target List
We describe the catalogs assembled and the algorithms used to populate the
revised TESS Input Catalog (TIC), based on the incorporation of the Gaia second
data release. We also describe a revised ranking system for prioritizing stars
for 2-minute cadence observations, and assemble a revised Candidate Target List
(CTL) using that ranking. The TIC is available on the Mikulski Archive for
Space Telescopes (MAST) server, and an enhanced CTL is available through the
Filtergraph data visualization portal system at the URL
http://filtergraph.vanderbilt.edu/tess_ctl.Comment: 30 pages, 16 figures, submitted to AAS Journals; provided to the
community in advance of publication in conjunction with public release of the
TIC/CTL on 28 May 201
HAZMAT VI: The Evolution of Extreme Ultraviolet Radiation Emitted from Early M Star
Quantifying the evolution of stellar extreme ultraviolet (EUV, 100 -- 1000
) emission is critical for assessing the evolution of
planetary atmospheres and the habitability of M dwarf systems. Previous studies
from the HAbitable Zones and M dwarf Activity across Time (HAZMAT) program
showed the far- and near-UV (FUV, NUV) emission from M stars at various stages
of a stellar lifetime through photometric measurements from the Galaxy
Evolution Explorer (GALEX). The results revealed increased levels of
short-wavelength emission that remain elevated for hundreds of millions of
years. The trend for EUV flux as a function of age could not be determined
empirically because absorption by the interstellar medium prevents access to
the EUV wavelengths for the vast majority of stars. In this paper, we model the
evolution of EUV flux from early M stars to address this observational gap. We
present synthetic spectra spanning EUV to infrared wavelengths of 0.4
0.05 M stars at five distinct ages between 10 and 5000 Myr, computed
with the PHOENIX atmosphere code and guided by the GALEX photometry. We model a
range of EUV fluxes spanning two orders of magnitude, consistent with the
observed spread in X-ray, FUV, and NUV flux at each epoch. Our results show
that the stellar EUV emission from young M stars is 100 times stronger than
field age M stars, and decreases as t after remaining constant for a few
hundred million years. This decline stems from changes in the chromospheric
temperature structure, which steadily shifts outward with time. Our models
reconstruct the full spectrally and temporally resolved history of an M star's
UV radiation, including the unobservable EUV radiation, which drives planetary
atmospheric escape, directly impacting a planet's potential for habitability.Comment: 23 pages, 15 figures, accepted to Ap
Understanding police officer resistance to body-worn cameras
Purpose
Body-worn cameras (BWCs) have been adopted in police agencies across the USA in efforts to increase police transparency and accountability. This widespread implementation has occurred despite some notable resistance to BWCs from police officers in some jurisdictions. This resistance poses a threat to the appropriate implementation of this technology and adherence to BWC policies. The purpose of this paper is to examine factors that could explain variation in officer receptivity to BWCs. Design/methodology/approach
The authors assess differences between officers who volunteered to wear a BWC and officers who resisted wearing a BWC as part of a larger randomized controlled trial of BWCs in the Phoenix Police Department. The authors specifically examine whether officer educational attainment, prior use of a BWC, attitudes toward BWCs, perceptions of organizational justice, support for procedural justice, noble cause beliefs, and official measures of officer activity predict receptivity to BWCs among 125 officers using binary logistic regression. Findings
The findings indicate limited differences between BWC volunteers and resistors. Volunteers did have higher levels of educational attainment and were more likely to agree that BWCs improve citizen behaviors, relative to their resistant counterparts. Interestingly, there were no differences in perceptions of organizational justice, self-initiated activities, use of force, or citizen complaints between these groups. Originality/value
Though a growing body of research has examined the impact of BWCs on officer use of force and citizen complaints, less research has examined officer attitudes toward the adoption of this technology. Extant research in this area largely focusses on general perceptions of BWCs, as opposed to officer characteristics that could predict receptivity to BWCs. This paper addresses this limitation in the research
A Multi-City Comparison of Front and Backyard Differences in Plant Species Diversity and Nitrogen Cycling in Residential landscapes
We hypothesize that lower public visibility of residential backyards reduces householdsâ desire for social conformity, which alters residential land management and produces differences in ecological composition and function between front and backyards. Using lawn vegetation plots (7 cities) and soil cores (6 cities), we examine plant species richness and evenness and nitrogen cycling of lawns in Boston, Baltimore, Miami, Minneapolis-St. Paul, Phoenix, Los Angeles (LA), and Salt Lake City (SLC). Seven soil nitrogen measures were compared because different irrigation and fertilization practices may vary between front and backyards, which may alter nitrogen cycling in soils. In addition to lawn-only measurements, we collected and analyzed plant species richness for entire yardsâcultivated (intentionally planted) and spontaneous (self-regenerating)âfor front and backyards in just two cities: LA and SLC. Lawn plant species and soils were not different between front and backyards in our multi-city comparisons. However, entire-yard plant analyses in LA and SLC revealed that frontyards had significantly fewer species than backyards for both cultivated and spontaneous species. These results suggest that there is a need for a more rich and social-ecologically nuanced understanding of potential residential, household behaviors and their ecological consequences
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Urban Biodiversity Experience and Exposure: Intervention and Inequality at the Local and Global Scale
As cities expand globally, researchers must clarify how human activities and institutions shape biodiversity and conversely, how ecological processes shape human outcomes. Two features of contemporary cities motivate this thesis. First, urban residents, and especially children, are spending less time in nature and consequently, miss out on healthy and formative experiences with biodiversity. Second, residents with the least access to biodiversity tend to be those with the lowest socioeconomic status (SES). Together, these patterns convey a multi-layered environmental injustice: not only might urbanites become increasingly estranged from biodiversity, disinterested from its conservation, and disconnected from its benefits, but these outcomes may be most acute in communities already suffering from inequality in terms of exposure to hazards or limited economic opportunity. The first chapter explores how childrenâs behaviors and interests change after learning about animal habitats first-hand in an environmental education program. I conducted an evaluation of the ECOS program in Springfield, Massachusetts, in which I surveyed elementary school students about their memories of ECOS and their related environmental behaviors. Students with parents or peers that had participated in ECOS were more likely to repeat or discuss program activities after the programâs end. Findings will aid educators in Springfield and beyond in improving program impacts and sustainability. The second chapter explains under what conditions socioeconomic inequality becomes linked with biodiversity. I conducted a meta-analysis of published research that assessed SES-biodiversity relationships in 34 cities using fuzzy-set Qualitative Comparative Analysis. I evaluated the contributions of study design and city-level conditions in shaping SES-biodiversity relationships for various taxonomic groups. The meta-analysis highlighted the contributions of residential and municipal decisions in differentially promoting biodiversity along socioeconomic lines. Further, we identified circumstances in which inequality in biodiversity was ameliorated or negated by urban form, social policy, or collective human preference. Findings will aid researchers and managers in understanding human drivers of biodiversity in their cities and how access to biodiversity may be unequally distributed. In sum, this thesis advances our knowledge about how biodiversity is structured in cities, who gets to experience it, and how such experiences influence our behaviors and interests
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