bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Rail Boot and Collection Mat to Control the Electrolysis of Rail and Utilities in DC Powered Transit Agencies
Authors: Memon Saud , Fromme Paul 
Published: June 2014

Stray current leakage and the corrosion caused by direct current (DC) traction power systems have been an ongoing issue especially in slab/embedded tracks. These tracks typically run through urban traffic areas, city centers, tunnels, and between the utility lines that require the rail to be continuously isolated to provide adequate track-to-earth resistance. Ballasted and direct fixation tracks provide much better track-to-earth resistance when equipped with isolation pads under the rail and exhibit higher stray current protection.
Various isolation techniques have been implemented by the DC powered rail transit agencies for the control of track-to-earth resistance in embedded tracks including the use of rail boot. In the last two decades, the practice of rail boot usage has seen a significant increase by transit agencies in the United States for controlling the leakage of current in embedded track sections. However, experience has shown that the rail boot alone cannot always control the stray current leakage and that it is important to supplement the rail boot with additional stray current collection and mitigation techniques. These methods thereby reduce the stray current corrosion by using various combinations of mitigation and collection techniques including, but not limited to, the use of elastomeric grout, insulated rail fasteners, embedding rail in troughs, providing current collection mats, and collector cables.
This paper presents and reviews different isolation and/or current collection methods that are presently in use to supplement the rail boot. These current isolation and/or collection methods when implemented together with the rail boot have significantly reduced stray current related problems, including: signal failures, controlling rail-to-earth voltages, minimizing recurring cost of repairs, and the damage to the public infrastructure. Additionally this paper provides general recommendations on the maintenance of the embedded tracks to avoid associated system problems.
Low-Cost Railway Level Crossings: Breaking Down the Barriers
Authors: Wullems Christian , Naweed Anjum 
Published: June 2014

Level crossing risk continues to be a significant safety concern for the security of rail operations around the world. Over the last decade or so, a third of railway related fatalities occurred as a direct result of collisions between road and rail vehicles in Australia. Importantly, nearly half of these collisions occurred at railway level crossings with no active protection, such as flashing lights or boom barriers. Current practice is to upgrade level crossings that have no active protection. However, the total number of level crossings found across Australia exceed 23,500, and targeting the proportion of these that are considered high risk (e.g. public crossings with passive controls) would cost in excess of AU$3.25 billion based on equipment, installation and commissioning costs of warning devices that are currently type approved.
Level crossing warning devices that are low-cost provide a potentially effective control for reducing risk; however, over the last decade, there have been significant barriers and legal issues in both Australia and the US that have foreshadowed their adoption. These devices are designed to have significantly lower lifecycle costs compared with traditional warning devices. They often make use of use of alternative technologies for train detection, wireless connectivity and solar energy supply. This paper describes the barriers that have been encountered for the adoption of these devices in Australia, including the challenges associated with: (1) determining requisite safety levels for such devices; (2) legal issues relating to duty of care obligations of railway operators; and (3) issues of Tort liability around the use of less than fail-safe equipment.
This paper provides an overview of a comprehensive safety justification that was developed as part of a project funded by a collaborative rail research initiative established by the Australian government, and describes the conceptual framework and processes being used to justify its adoption. The paper provides a summary of key points from peer review and discusses prospective barriers that may need to be overcome for future adoption. A successful outcome from this process would result in the development of a guideline for decision-making, providing a precedence for adopting low-cost level crossing warning devices in other parts of the world. The framework described in this paper also provides relevance to the review and adoption of analogous technologies in rail and other safety critical industries.
Benefits of Using Modern Axle Counters in CBTC and Light Rail Projects
Authors: Grundnig Gerhard , Pucher Christian 
Published: June 2014

Wheel detection and axle counting systems provide the basic information for track vacancy detection, for controlling level crossing systems and a range of switching tasks or trigger functions. This technology is established throughout the world for standard gauge railways and is increasingly replacing track circuits.
The requirements and the framework conditions in rail-based public transportation systems do, however, differ significantly from those in the standard-gauge railway and long distance track sectors. Nevertheless, in this segment too there is a clear trend towards wheel detection and axle counting systems.
New lines and projects are increasingly being equipped with modern axle counting systems due to the benefits in terms of functionality and operating costs. Nowadays even in railed public transport systems, there is a clear move from track circuit systems to wheel detection and axle counting technology.
Video Analytics for the Detection of Near-Miss Incidents on Approach to Railway Level Crossings
Authors: Aminmansour Sina , Maire Frederic , Wullems Christian 
Published: June 2014

Recent modelling of socio-economic costs by the Australian railway industry in 2010 has estimated the cost of level crossing accidents to exceed AU$116 million annually. To better understand causal factors that contribute to these accidents, the Cooperative Research Centre for Rail Innovation is running a project entitled Baseline Level Crossing Video. The project aims to improve the recording of level crossing safety data by developing an intelligent system capable of detecting near-miss incidents and capturing quantitative data around these incidents. To detect near-miss events at railway level crossings a video analytics module is being developed to analyse video footage obtained from forward-facing cameras installed on trains. This paper presents a vision base approach for the detection of these near-miss events.
The video analytics module is comprised of object detectors and a rail detection algorithm, allowing the distance between a detected object and the rail to be determined. An existing publicly available Histograms of Oriented Gradients (HOG) based object detector algorithm is used to detect various types of vehicles in each video frame. As vehicles are usually seen from a sideway view from the cabin’s perspective, the results of the vehicle detector are verified using an algorithm that can detect the wheels of each detected vehicle.
Rail detection is facilitated using a projective transformation of the video, such that the forward-facing view becomes a bird’s eye view. Line Segment Detector is employed as the feature extractor and a sliding window approach is developed to track a pair of rails. Localisation of the vehicles is done by projecting the results of the vehicle and rail detectors on the ground plane allowing the distance between the vehicle and rail to be calculated. The resultant vehicle positions and distance are logged to a database for further analysis.
We present preliminary results regarding the performance of a prototype video analytics module on a data set of videos containing more than 30 different railway level crossings. The video data is captured from a journey of a train that has passed through these level crossings.
Crippling Test of a Budd M-1 Passenger Railcar: Test and Analysis Results
Authors: Carolan Michael , Perlman Benjamin , Tyrell David , Gordon Jeff 
Published: June 2014

The Federal Railroad Administration’s (FRA) Office of Research and Development is conducting research into the occupied volume integrity (OVI) of passenger railcars. OVI refers to a passenger railcar’s ability to preserve space for passengers and crew during accident loading conditions. The information developed in this research program will form the basis for establishing alternative OVI evaluation procedures. These alternative procedures, in turn, will allow a wider variety of passenger railcar designs to have their OVI evaluated, will provide guidance for applying modern engineering technologies, such as finite element analysis (FEA), and will continue to ensure a level of safety in evaluated vehicles equivalent to conventional evaluation.
As part of this research program, two tests and corresponding FEA were conducted on a Budd M-1 passenger railcar that had been retrofitted with crash energy management (CEM) components on both ends. This testing and analysis program was sponsored by FRA and carried out by Transportation Technology Center, Inc. (TTCI), Arup, and the Volpe Center. An 800,000 pound load test was conducted on March 13, 2013 and was intended to elastically deform the car. The data generated during this test were, in turn, used to validate FE models of the M-1 car. The second test was performed on July 17, 2013. This test introduced loads into the occupant volume through its CEM attachment points until the ultimate, or crippling, load was reached. By loading the occupant volume through the CEM components, the test load path is similar to the load path that would be traveled by collision loads during activation of the CEM system.
This paper presents the results of the crippling test, discusses the sequence of buckling that was observed to occur in the test, and compares the results of the test with the results from FEA of the test conditions. During the crippling test, the car exhibited a crippling load of 1.1 million pounds. This value is consistent with crippling loads reached by two Budd Pioneer cars that were previously tested in an FRA program. The buckling sequence of the members making up the M-1’s occupant volume were particularly well-captured by strain gages during this most recent test. The load path through the occupant volume and the sequence of progressive buckling of structural members is discussed. Additionally, the presence of existing damage and previously-repaired areas and their likely effects on the crippling behavior of the car are discussed.
FRA Autonomous Track Geometry Measurement System Technology Development: Past, Present, and Future
Authors: Saadat Soheil , Stuart Cameron , Carr Gary , Payne James 
Published: June 2014

The Federal Railroad Administration’s (FRA’s) Office of Research and Development has undertaken a multi-phase research program focused on the development and advancement of Autonomous Track Geometry Measurement Systems (ATGMS) and related technologies to improve rail safety by increasing the availability of track geometry data for safety and maintenance planning purposes. Benefits of widespread use of ATGMS technology include reduced life-cycle cost of inspection operations, minimized interference with revenue operations, and increased inspection frequencies.
FRA’s Office of Research and Development ATGMS research program results have demonstrated that the paradigm of track inspection and maintenance practices, information management and, eventually, government regulations will change as a result of widespread use of ATGMS technology by the industry. A natural consequence of increased inspection frequencies associated with ATGMS is the large amount of actionable information produced. Therefore, changing existing maintenance practices to address a larger number of identified track issues across large geographic areas will be a challenge for the industry. In addition, managing ATGMS data and assessing the quality of this information in a timely manner will be challenging.
This paper presents an overview of the FRA’s ATGMS research program with emphasis on its evolution from a proof-of-concept prototype to a fully operational measurement system. It presents the evolution of ATGMS technology over time including the development of a web-based application for data editing, management and quality assurance. Finally, it presents FRA’s vision for the future of the ATGMS technology.
Risk Factors and Outcomes for Patients with Bloodstream Infection Due to Acinetobacter baumannii-calcoaceticus Complex
Authors: Chopra Teena , Marchaim Dror , Johnson Paul C. , Awali Reda A. , Doshi Hardik , Chalana Indu , Davis Naomi , Zhao Jing J. , Pogue Jason M. , Parmar Sapna , Kaye Keith S. 
Published: June 2014

ABSTRACT

Identifying patients at risk for bloodstream infection (BSI) due to
Acinetobacter baumannii
-
Acinetobacter calcoaceticus
complex (ABC) and providing early appropriate therapy are critical for improving patient outcomes. A retrospective matched case-control study was conducted to investigate the risk factors for BSI due to ABC in patients admitted to the Detroit Medical Center (DMC) between January 2006 and April 2009. The cases were patients with BSI due to ABC; the controls were patients not infected with ABC. Potential risk factors were collected 30 days prior to the ABC-positive culture date for the cases and 30 days prior to admission for the controls. A total of 245 case patients were matched with 245 control patients. Independent risk factors associated with BSI due to ABC included a Charlson's comorbidity score of ≥3 (odds ratio [OR], 2.34;
P
= 0.001), a direct admission from another health care facility (OR, 4.63;
P
< 0.0001), a prior hospitalization (OR, 3.11;
P
< 0.0001), the presence of an indwelling central venous line (OR, 2.75;
P
= 0.011), the receipt of total parenteral nutrition (OR, 21.2;
P
< 0.0001), the prior receipt of β-lactams (OR, 3.58;
P
< 0.0001), the prior receipt of carbapenems (OR, 3.18;
P
= 0.006), and the prior receipt of chemotherapy (OR, 15.42;
P
< 0.0001). The median time from the ABC-positive culture date to the initiation of the appropriate antimicrobial therapy was 2 days (interquartile range [IQR], 1 to 3 days). The in-hospital mortality rate was significantly higher among case patients than among control patients (OR, 3.40;
P
< 0.0001). BSIs due to ABC are more common among critically ill and debilitated institutionalized patients, who are heavily exposed to health care settings and invasive devices.
Evaluation of Vancomycin Population Susceptibility Analysis Profile as a Predictor of Outcomes for Patients with Infective Endocarditis Due to Methicillin-Resistant Staphylococcus aureus
Authors: Casapao Anthony M. , Davis Susan L. , McRoberts John Paul , Lagnf Abdalhamid M. , Patel Sonal , Kullar Ravina , Levine Donald P. , Rybak Michael J. 
Published: June 2014

ABSTRACT

Infective endocarditis due to methicillin-resistant
Staphylococcus aureus
(MRSA IE) is associated with high morbidity and mortality. Vancomycin continues to be the primary treatment for this disease. The emergence of heterogeneous vancomycin-intermediate
Staphylococcus aureus
(hVISA), defined as a modified population analysis profile (PAP) of ≥0.9, may affect patient outcomes. The objective of this study was to evaluate the relationship of vancomycin subpopulation susceptibility and the clinical outcomes of MRSA IE. We conducted a retrospective cohort study of patients treated with vancomycin for MRSA IE from 2002 to 2013 at the Detroit Medical Center. A modified PAP was used to measure the vancomycin PAP MIC and the PAP-to-area under the curve (AUC) ratio. Treatment failure was defined as bacteremia for ≥7 days or death attributed to MRSA. Classification and regression tree (CART) analysis was used to select a failure breakpoint between the PAP-AUC ratios and the PAP MIC. A total of 202 patients were included in the study. Twenty-seven percent of the patients had left-sided IE, 19% of the strains were hVISA, and 70% of the strains were staphylococcal cassette chromosome
mec
element (SCC
mec
) type IV. Overall treatment failure was observed in 64%; 59% had persistent bacteremia, and the 30-day attributable mortality rate was 21%. The CART breakpoint between failure and success in terms of the PAP-AUC ratio was 0.9035. On logistic regression analysis, intensive care unit (ICU) admission (adjusted odds ratio [aOR], 2.8; 95% confidence interval [CI], 1.5 to 5.2) and a PAP MIC of ≥4 mg/liter (aOR, 3.2; 95% CI, 1.3 to 8.4) were associated with failure (
P
= 0.001 and 0.015, respectively). A PAP MIC of ≥4 mg/liter and ICU admission were significant for treatment failure for patients with MRSA IE. The PAP-AUC ratio of ≥0.9035 predicted failure consistent with the hVISA definition. The role of population MIC analysis in predicting outcome with MRSA infections warrants further investigation.
Caspofungin at Catheter Lock Concentrations Eradicates Mature Biofilms of Candida lusitaniae and Candida guilliermondii
Authors: Simitsopoulou Maria , Kyrpitzi Daniela , Velegraki Aristea , Walsh Thomas J. , Roilides Emmanuel 
Published: June 2014

ABSTRACT

The antibiofilm activities of caspofungin, anidulafungin, micafungin, and liposomal amphotericin B were studied against
Candida lusitaniae
,
Candida guilliermondii
, and a
Candida albicans
control strain. While anidulafungin and micafungin (0.007 to 2,048 mg/liter) showed reduced activity against biofilms of both test species, caspofungin displayed concentration-dependent antibiofilm activity, reaching complete and persistent eradication at concentrations achievable during lock therapy (512 to 2,048 mg/liter,
P
< 0.05). Although liposomal amphotericin B strongly inhibited mature biofilms, it possessed lower antibiofilm activity than caspofungin (
P
< 0.05).
Edwardsiella tarda-Induced Cytotoxicity Depends on Its Type III Secretion System and Flagellin
Authors: Xie Hai-Xia , Lu Jin-Fang , Rolhion Nathalie , Holden David W. , Nie Pin , Zhou Ying , Yu Xiu-Jun 
Published: June 2014

ABSTRACT

Many Gram-negative bacteria utilize a type III secretion system (T3SS) to translocate virulence proteins into host cells to cause diseases. In responding to infection, macrophages detect some of the translocated proteins to activate caspase-1-mediated cell death, called pyroptosis, and secretion of proinflammatory cytokines to control the infection.
Edwardsiella tarda
is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and both gastrointestinal and extraintestinal infections in humans. In this study, we report that the T3SS of
E. tarda
facilitates its survival and replication in murine bone marrow-derived macrophages, and
E. tarda
infection triggers pyroptosis of infected macrophages from mice and fish and increased secretion of the cytokine interleukin 1β in a T3SS-dependent manner. Deletion of the flagellin gene
fliC
of
E. tarda
results in decreased cytotoxicity for infected macrophages and does not attenuate its virulence in a fish model of infection, whereas upregulated expression of FliC in the
fliC
mutant strain reduces its virulence. We propose that the host controls
E. tarda
infection partially by detecting FliC translocated by the T3SS, whereas the bacteria downregulate the expression of FliC to evade innate immunity.
Genes Required for Assembly of Pili Associated with the Helicobacter pylori cag Type IV Secretion System
Authors: Johnson Elizabeth M. , Gaddy Jennifer A. , Voss Bradley J. , Hennig Ewa E. , Cover Timothy L. 
Published: June 2014

ABSTRACT

Helicobacter pylori
causes numerous alterations in gastric epithelial cells through processes that are dependent on activity of the
cag
type IV secretion system (T4SS). Filamentous structures termed “pili” have been visualized at the interface between
H. pylori
and gastric epithelial cells, and previous studies suggested that pilus formation is dependent on the presence of the
cag
pathogenicity island (PAI). Thus far, there has been relatively little effort to identify specific genes that are required for pilus formation, and the role of pili in T4SS function is unclear. In this study, we selected 7 genes in the
cag
PAI that are known to be required for T4SS function and investigated whether these genes were required for pilus formation.
cagT
,
cagX
,
cagV
,
cagM
, and
cag3
mutants were defective in both T4SS function and pilus formation; complemented mutants regained T4SS function and the capacity for pilus formation.
cagY
and
cagC
mutants were defective in T4SS function but retained the capacity for pilus formation. These results define a set of
cag
PAI genes that are required for both pilus biogenesis and T4SS function and reveal that these processes can be uncoupled in specific mutant strains.
Colonization of Cecum Is Important for Development of Persistent Infection by Yersinia pseudotuberculosis
Authors: Fahlgren Anna , Avican Kemal , Westermark Linda , Nordfelth Roland , Fällman Maria 
Published: June 2014

ABSTRACT

Yersiniosis is a human disease caused by the bacterium
Yersinia pseudotuberculosis
or
Yersinia enterocolitica
. The infection is usually resolved but can lead to postinfectious sequelae, including reactive arthritis and erythema nodosum. The commonly used
Yersinia
mouse infection model mimics acute infection in humans to some extent but leads to systemic infection and eventual death. Here, we analyzed sublethal infection doses of
Y. pseudotuberculosis
in mice in real time using bioluminescent imaging and found that infections using these lower doses result in extended periods of asymptomatic infections in a fraction of mice. In a search for the site for bacterial persistence, we found that the cecum was the primary colonization site and was the site where the organism resided during a 115-day infection period. Persistent infection was accompanied by sustained fecal shedding of cultivable bacteria. Cecal patches were identified as the primary site for cecal colonization during persistence.
Y. pseudotuberculosis
bacteria were present in inflammatory lesions, in localized foci, or as single cells and also in neutrophil exudates in the cecal lumen. The chronically colonized cecum may serve as a reservoir for dissemination of infection to extraintestinal sites, and a chronic inflammatory state may trigger the onset of postinfectious sequelae. This novel mouse model for bacterial persistence in cecum has potential as an investigative tool to unveil a deeper understanding of bacterial adaptation and host immune defense mechanisms during persistent infection.