1,862 research outputs found
From Buses to BRT: Case Studies of Incremental BRT Projects in North America, MTI Report 09-13
Bus Rapid Transit (BRT) uses different combinations of techniques to improve service, such as bus-only lanes and roads, pre-boarding fare collection, transit priority at traffic signals, stylish vehicles with extra doors, bus stops that are more like light rail stations, and high frequency service. This study examines five approaches to BRT systems as implemented by public transit agencies in California, Oregon, and Ontario. The case studies as a group show that BRT can be thought of as a discretionary combination of elements that can be assembled in many different combinations over time. Every element incrementally adds to the quality or attractiveness of the service. This latitude provides transit agencies with many benefits, including the ability to match infrastructure with operating requirements. For example, a BRT service can combine operations serving free flowing arterial roads in the fringes of the downtown with dedicated lanes in areas closer to city center where congestion is greatest. Buses can operate both on and off the guide way, extending the corridors in which passengers are offered a one-seat ride with no transfer required. Transit agencies also can select specific BRT components and strategies, such as traffic signal priority and increased stop spacing, and apply them to existing local bus operations as a way to increase bus speeds and reduce operating costs. The specific elements selected for a BRT route can be implemented all at once, or in incremental stages either or both geographical extensions or additions of features. All of the case studies showed ridership improvements, but the Los Angeles Metro Rapid bus system illustrates the wide geographic coverage, improved ridership, and moderate cost per new rider that is possible with an approach that includes fewer BRT features spread over more miles of route. Quantitative results from the case studies suggest that incremental improvements, applied widely to regional bus networks, may be able to achieve significant benefits at a lower cost than substantial infrastructure investments focused upon just one or a few corridors
A Method for Rapid Determination of the Icing Limit of a Body in Terms of the Stream Conditions
The effects of existing frictional heating were analyzed to determine the conditions under which ice formations on aircraft surfaces can be prevented. A method is presented for rapidly determining by means of charts the combination of-Mach number, altitude, and stream temperature which will maintain an ice-free surface in an icing cloud. The method can be applied to both subsonic and supersonic flow. The charts presented are for Mach numbers up to 1.8 and pressure altitudes from sea level to 45,000 feet
Joint Total Variation ESTATICS for Robust Multi-Parameter Mapping
Quantitative magnetic resonance imaging (qMRI) derives tissue-specific
parameters -- such as the apparent transverse relaxation rate R2*, the
longitudinal relaxation rate R1 and the magnetisation transfer saturation --
that can be compared across sites and scanners and carry important information
about the underlying microstructure. The multi-parameter mapping (MPM) protocol
takes advantage of multi-echo acquisitions with variable flip angles to extract
these parameters in a clinically acceptable scan time. In this context,
ESTATICS performs a joint loglinear fit of multiple echo series to extract R2*
and multiple extrapolated intercepts, thereby improving robustness to motion
and decreasing the variance of the estimators. In this paper, we extend this
model in two ways: (1) by introducing a joint total variation (JTV) prior on
the intercepts and decay, and (2) by deriving a nonlinear maximum \emph{a
posteriori} estimate. We evaluated the proposed algorithm by predicting
left-out echoes in a rich single-subject dataset. In this validation, we
outperformed other state-of-the-art methods and additionally showed that the
proposed approach greatly reduces the variance of the estimated maps, without
introducing bias.Comment: 11 pages, 2 figures, 1 table, conference paper, accepted at MICCAI
202
G20 2014: the G20 Brisbane Summit, inequality, energy and anti-corruption
The 12th edition of the G20 monitor contains an overview from John Lipsky on the G20’s role in global governance after the global financial crisis; a paper by Geoff Weir on the G20, Thomas Piketty, and inequality; thoughts from Hugh Jorgensen and Christian Downie on multilateral energy governance; and a piece by Charles Sampford on integrity and anti-corruption.
Key findings
Lipsky suggests the Brisbane Summit is a critical moment for the G20, if it does not restore a sense of political momentum to the process, the G20’s relevance will wane
Ever-growing inequality is inconsistent with the maintenance of an inclusive, democratic system of governance. The G20 should consider a combination of taxation, education and health reforms to reduce inequality.
The world needs better multilateral energy governance. Whether the conditions exist for the G20 to remedy this problem is unclear, but members should pursue energy governance mechanisms that promote trust
Orthopaedic surgeons and the medical device industry: The threat to scientific integrity and the public trust
Internet Promotion of Direct Anterior Approach Total Hip Arthroplasty by Members of the American Association of Hip and Knee Surgeons
Introduction
The Direct Anterior approach (DAA) in total hip arthroplasty (THA) is of significant interest to both patients and surgeons, largely due to intense marketing. This study addressed the question, ‘What is the level of promotion of DAA THA on the internet by American Association of Hip and Knee Surgeons (AAHKS) members?’
Methods
An internet search was performed to identify surgeon-specific websites for each member of the AAHKS using the members’ full name and a previously published set of criteria. Each website was evaluated utilizing a questionnaire to systematically identify claims made regarding proposed DAA specific risks, benefits, as well as the presence/absence of supporting data.
Results
We identified 1,855 qualified websites. The DAA was referenced on 22.8% (423/1,855) of these websites. Claims regarding DAA specific benefits included; less invasive/muscle sparing (46.3%), quicker recovery (45.2%), decreased pain (28.1%), decreased hospital stay (22.0%), and decreased dislocation risk (16.3%). Potential DAA risks including lateral femoral cutaneous nerve injury, peri-prosthetic/greater trochanteric fracture, and wound complication/hematoma were addressed on only 4.7%, 3.1%, and 1.7% of websites, respectively. Supporting peer-reviewed literature was identified on only 3.6% of DAA websites.
Conclusions
Over one fifth of AAHKS members promoted the DAA on the internet. Member websites claimed DAA benefits such as faster recovery and decreased pain approximately nine times more frequently than any potential risk of the procedure (p < 0.001). While AAHKS policy does not regulate member marketing, it is the responsibility of all orthopaedic surgeons to disseminate accurate, validated information concerning the procedures we perform
Are there three main subgroups within the patellofemoral pain population? A detailed characterisation study of 127 patients to help develop targeted Intervention (TIPPs)
• Background
Current multimodal approaches for the management of non-specific patellofemoral pain are not optimal, however, targeted intervention for subgroups could improve patient outcomes. This study explores whether subgrouping of non-specific patellofemoral pain patients, using a series of low cost simple clinical tests, is possible.
• Method
The exclusivity and clinical importance of potential subgroups was assessed by applying à priori test thresholds (1 SD) from seven clinical tests in a sample of adult patients with non-specific patellofemoral pain. Hierarchical clustering and latent profile analysis, were used to gain additional insights into subgroups using data from the same clinical tests.
• Results
One hundred and thirty participants were recruited, 127 had complete data: 84 (66%) female, mean age 26 years (SD 5.7) and mean BMI 25.4 (SD 5.83), median (IQR) time between onset of pain and assessment was 24 (7-60) months. Potential subgroups defined by the à priori test thresholds were not mutually exclusive and patients frequently fell into multiple subgroups. Using hierarchical clustering and latent profile analysis three subgroups were identified using 6 of the 7 clinical tests. These subgroups were given the following nomenclature: (i) ‘strong’, (ii) ‘weak and tighter’, and (iii) ‘weak and pronated foot’.
• Conclusions
We conclude that three subgroups of patellofemoral patients may exist based on the results of six clinical tests which are feasible to perform in routine clinical practice. Further research is needed to validate these findings in other datasets and, if supported by external validation, to see if targeted interventions for these subgroups improve patient outcomes
Planning guidelines for koala conservation and recovery: A guide to best planning practice
The information contained in the guide is a synthesis of four years research into the conservation and restoration of koala populations in fragmented landscapes of eastern Australia. The guidelines also capture a decade of practical research and planning experience by the Australian Koala Foundation in mapping koala habitat and developing koala conservation and management plans for local government areas in New South Wales. They draw on the collective knowledge of researchers who wanted to see their results put into action with practical outcomes for koala conservation
A novel strategy to reduce very late HIV diagnosis in high-prevalence areas in South-West England:serious incident audit
Indicators of social development: conceptual and methodological considerations in monitoring the health sector
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