4,605 research outputs found
Designing and Operating Safe and Secure Transit Systems: Assessing Current Practices in the United States and Abroad, MTI Report 04-05
Public transit systems around the world have for decades served as a principal venue for terrorist acts. Today, transit security is widely viewed as an important public policy issue and is a high priority at most large transit systems and at smaller systems operating in large metropolitan areas. Research on transit security in the United States has mushroomed since 9/11; this study is part of that new wave of research. This study contributes to our understanding of transit security by (1) reviewing and synthesizing nearly all previously published research on transit terrorism; (2) conducting detailed case studies of transit systems in London, Madrid, New York, Paris, Tokyo, and Washington, D.C.; (3) interviewing federal officials here in the United States responsible for overseeing transit security and transit industry representatives both here and abroad to learn about efforts to coordinate and finance transit security planning; and (4) surveying 113 of the largest transit operators in the United States. Our major findings include: (1) the threat of transit terrorism is probably not universalâmost major attacks in the developed world have been on the largest systems in the largest cities; (2) this asymmetry of risk does not square with fiscal politics that seek to spread security funding among many jurisdictions; (3) transit managers are struggling to balance the costs and (uncertain) benefits of increased security against the costs and (certain) benefits of attracting passengers; (4) coordination and cooperation between security and transit agencies is improving, but far from complete; (5) enlisting passengers in surveillance has benefits, but fearful passengers may stop using public transit; (6) the role of crime prevention through environmental design in security planning is waxing; and (7) given the uncertain effectiveness of antitransit terrorism efforts, the most tangible benefits of increased attention to and spending on transit security may be a reduction in transit-related person and property crimes
Progressive respiratory disease:the importance of prognostic conversations and advance care planning
Coherence in Selection: The Influence of Coachesâ Views and Beliefs on Nominations for a Male Rugby Union Talent System
Selection is a key process for a talent system, requiring stakeholders to make decisions regarding athlete suitability for the increased resourcing of a specific talent development environment. Most selections require coaches to make judgements based on predicting an individualâs fit to a
specific sport and environment. Previous research has highlighted the integration of stakeholders and system as being a key feature of effective talent development. Yet, as regards selection, there has been little research exploring the influence of shared perceptions and values on selection. This paper explores these shared perceptions at the first stages of selection in a rugby union talent system. Specifically, using semi-structured interviews (n = 12) with stakeholders within a single region, this research looked to understand the level of integration between a regional âDeveloping Player Programâ and its feeder clubs and schools. Using reflexive thematic analysis, varying levels of integration between stakeholders were apparent, with stakeholdersâ views and beliefs influencing selection decisions. The findings suggest that at the earliest stages of talent systems, optimal practice requires an understanding of the purpose of selection and the overall system. This shared understanding is likely supported by a two-way interaction from both the top-down and bottom-up, with the aim of increasing integration across a large network of stakeholders
Spatial dependency between task positive and task negative networks
Functional neuroimaging reveals both relative increases (task-positive) and
decreases (task-negative) in neural activation with many tasks. There are
strong spatial similarities between many frequently reported task-negative
brain networks, which are often termed the default mode network. The default
mode network is typically assumed to be a spatially-fixed network; however,
when defined by task-induced deactivation, its spatial distribution it varies
depending on what specific task is being performed. Many studies have revealed
a strong temporal relationship between task-positive and task-negative networks
that are important for efficient cognitive functioning and here. Here, using
data from four different cognitive tasks taken from two independent datasets,
we test the hypothesis that there is also a fundamental spatial relationship
between them. Specifically, it is hypothesized that the distance between task
positive and negative-voxels is preserved despite different spatial patterns of
activation and deactivation being evoked by different cognitive tasks. Here, we
show that there is lower variability in the distance between task-positive and
task-negative voxels across four different sensory, motor and cognitive tasks
than would be expected by chance - implying that deactivation patterns are
spatially dependent on activation patterns (and vice versa) and that both are
modulated by specific task demands. We propose that this spatial relationship
may be the macroscopic analogue of microscopic neuronal organization reported
in sensory cortical systems, and we speculate why this spatial organization may
be important for efficient sensorimotor and cognitive functioning.Comment: 16 pages, 4 figure
Examining the impact of coaching for independence in adventure sports
This study of adventure sports learners expands on earlier work on adventure sports coaching. We examine learnersâ perceptions of their coaching and its effect on their self-efficacy and independence as adventure sports performers. We utilise a convergent mixed approach that deploys the Outdoor Recreation Self-Efficacy Scale, pre- and post-coaching, and a reflexive thematic analysis of semi-structured interviews. The findings indicate improved self-efficacy and greater independence as a result of the coachâs practice, supporting our initial conjecture that the adventure sports coaches in this study developed independence as a definable outcome of their coaching practice
Mixed valency in cerium oxide crystallographic phases: Determination of valence of the different cerium sites by the bond valence method
We have applied the bond valence method to cerium oxides to determine the
oxidation states of the Ce ion at the various site symmetries of the crystals.
The crystals studied include cerium dioxide and the two sesquioxides along with
some selected intermediate phases which are crystallographically well
characterized. Our results indicate that cerium dioxide has a mixed-valence
ground state with an f-electron population on the Ce site of 0.27 while both
the A- and C-sesquioxides have a nearly pure f^1 configuration. The Ce sites in
most of the intermediate oxides have non-integral valences. Furthermore, many
of these valences are different from the values predicted from a naive
consideration of the stoichiometric valence of the compound
Evidence for a very slow X-ray pulsar in 2S0114+650 from RXTE All-Sky Monitor Observations
Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM) observations of the
X-ray binary 2S0114+650 show modulations at periods close to both the optically
derived orbital period (11.591 days) and proposed pulse period (~ 2.7 hr). The
pulse period shows frequency and intensity variability during the more than 2
years of ASM observations analyzed. The pulse properties are consistent with
this arising from accretion onto a rotating neutron star and this would be the
slowest such period known. The shape of the orbital light curve shows
modulation over the course of the entire orbit and a comparison is made with
the orbital light curve of Vela X-1. However, the expected phase of eclipse,
based on an extrapolation of the optical ephemeris, does not correspond with
the observed orbital minimum. The orbital period derived from the ASM light
curve is also slightly longer than the optical period.Comment: To be published in the Astrophysical Journal, 1999, volume 511. 9
figure
The analysis of rapidly developing fog at the Kennedy Space Center
This report documents fog precursors and fog climatology at Kennedy Space Center (KSC) Florida from 1986 to 1990. The major emphasis of this report focuses on rapidly developing fog events that would affect the less than 7-statute mile visibility rule for End-Of-Mission (EOM) Shuttle landing at KSC (Rule 4-64(A)). The Applied Meteorology Unit's (AMU's) work is to: develop a data base for study of fog associated weather conditions relating to violations of this landing constraint; develop forecast techniques or rules-of-thumb to determine whether or not current conditions are likely to result in an acceptable condition at landing; validate the forecast techniques; and transition techniques to operational use. As part of the analysis the fog events were categorized as either advection, pre-frontal or radiation. As a result of these analyses, the AMU developed a fog climatological data base, identified fog precursors and developed forecaster tools and decision trees. The fog climatological analysis indicates that during the fog season (October to April) there is a higher risk for a visibility violation at KSC during the early morning hours (0700 to 1200 UTC), while 95 percent of all fog events have dissipated by 1600 UTC. A high number of fog events are characterized by a westerly component to the surface wind at KSC (92 percent) and 83 percent of the fog events had fog develop west of KSC first (up to 2 hours). The AMU developed fog decision trees and forecaster tools that would help the forecaster identify fog precursors up to 12 hours in advance. Using the decision trees as process tools ensures the important meteorological data are not overlooked in the forecast process. With these tools and a better understanding of fog formation in the local KSC area, the Shuttle weather support forecaster should be able to give the Launch and Flight Directors a better KSC fog forecast with more confidence
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