bluuebunny/crossref_metadata_2025 huggingface dataset:
IL1α and IL4 signalling in human ovarian surface epithelial cells
Authors: Papacleovoulou Georgia , Critchley Hilary O D , Hillier Stephen G , Mason J Ian
Published: September 2011

The human ovarian surface epithelium (hOSE) is a mesothelial layer that surrounds the ovary and undergoes injury and repair cycles after ovulation-associated inflammation. We previously showed that IL4 is a key regulator of progesterone bioavailability during post-ovulatory hOSE repair as it differentially up-regulated3β-HSD1and3β-HSD2mRNA transcripts and total 3β-hydroxysteroid dehydrogenase activity whereas it inhibited androgen receptor (AR) expression. We now show that the pro-inflammatory effect of IL1α on3β-HSD1expression is mediated by nuclear factor-κB (NF-κB), whereas its anti-inflammatory action on3β-HSD2expression is exerted via p38 mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K) and NF-κB signalling pathways. The anti-inflammatory IL4 effects on3β-HSD1and3β-HSD2mRNA expression are mediated through STAT6 and PI3K signalling networks. IL4 effects onARand3β-HSD2expression involve the p38 MAPK pathway. We also document that IL4 up-regulates lysyl oxidase (LOX) mRNA transcripts, a key gene for extracellular matrix (ECM) deposition and inhibits IL1α-induced expression of cyclooxygenase-2 (COX-2) mRNA, a gene involved in breakdown of ECM, showing a further role in post-ovulatory wound healing. We conclude that IL1α and IL4 actions in the post-ovulatory wound healing of hOSE cells are mediated by different signalling transduction pathways. The p38 MAPK signalling pathway may have possible therapeutic benefit in inflammation-associated disorders of the ovary, including cancer.
Global Igfbp1 deletion does not affect prostate cancer development in a c-Myc transgenic mouse model
Authors: Gray Ashley , Aronson William J , Barnard R James , Mehta Hemal , Wan Junxiang , Said Jonathan , Cohen Pinchas , Galet Colette
Published: September 2011

Circulating insulin-like growth factor binding protein 1 (IGFBP1) levels vary in response to nutritional status, and pre-clinical studies suggest that elevated IGFBP1 may be protective against the development and progression of prostate cancer. We hypothesized that global deletion ofIgfbp1would accelerate the development of prostate cancer in a c-Myc transgenic mouse model. To test our hypothesis, c-Myc transgenic mice (Myc/BP-1 wild-type (WT)) were crossed and interbred with theIgfbp1knockout mice (Myc/BP-1 KO). The animals were placed on a high-protein diet at weaning, weighed every 2 weeks, and euthanized at 16 weeks of age. Prostate histopathology was assessed and proliferation status was determined by Ki-67 and proliferating cell nuclear antigen analyses. IGF-related serum biomarkers and body composition were measured. No significant difference in the incidence of prostate cancer was observed between the Myc/BP-1 KO and the Myc/BP-1 WT mice (65 and 80% respectively,P=0.48). Proliferation was significantly decreased by 71% in prostate tissue of Myc/BP-1 KO mice compared with Myc/BP-1 WT mice. Myc/BP-1 KO mice exhibited a significant 6.7% increase in body weight relative to the Myc/BP-1 WT mice that was attributed to an increase in fat mass. Fasting insulin levels were higher in the Myc/BP-1 KO mice without any difference between the groups in fasting glucose concentrations. Thus, contrary to our hypothesis, global deletion ofIgfbp1in a c-Myc transgenic mouse model did not accelerate the development of prostate cancer. GlobalIgfbp1deletion did result in a significant increase in body weight and body fat mass. Further studies are required to understand the underlying mechanisms for these metabolic effects.
AMP-activated protein kinase pathway and bone metabolism
Authors: Jeyabalan J , Shah M , Viollet B , Chenu C
Published: September 2011

There is increasing evidence that osteoporosis, similarly to obesity and diabetes, could be another disorder of energy metabolism. AMP-activated protein kinase (AMPK) has emerged over the last decade as a key sensing mechanism in the regulation of cellular energy homeostasis and is an essential mediator of the central and peripheral effects of many hormones on the metabolism of appetite, fat and glucose. Novel work demonstrates that the AMPK signaling pathway also plays a role in bone physiology. Activation of AMPK promotes bone formationin vitroand the deletion of α or β subunit of AMPK decreases bone mass in mice. Furthermore, AMPK activity in bone cells is regulated by the same hormones that regulate food intake and energy expenditure through AMPK activation in the brain and peripheral tissues. AMPK is also activated by antidiabetic drugs such as metformin and thiazolidinediones (TZDs), which also impact on skeletal metabolism. Interestingly, TZDs have detrimental skeletal side effects, causing bone loss and increasing the risk of fractures, although the role of AMPK mediation is still unclear. These data are presented in this review that also discusses the potential roles of AMPK in bone as well as the possibility for AMPK to be a future therapeutic target for intervention in osteoporosis.
5α-Reduced glucocorticoids: a story of natural selection
Authors: Nixon Mark , Upreti Rita , Andrew Ruth
Published: September 2011

5α-Reduced glucocorticoids (GCs) are formed when one of the two isozymes of 5α-reductase reduces the Δ4–5double bond in the A-ring of GCs. These steroids are largely viewed inert, despite the acceptance that other 5α-dihydro steroids, e.g. 5α-dihydrotestosterone, retain or have increased activity at their cognate receptors. However, recent findings suggest that 5α-reduced metabolites of corticosterone have dissociated actions on GC receptors (GRs)in vivoandin vitroand are thus potential candidates for safer anti-inflammatory steroids. 5α-Dihydro- and 5α-tetrahydro-corticosterone can bind with GRs, but interest in these compounds had been limited, since they only weakly activated metabolic gene transcription. However, a greater understanding of the signalling mechanisms has revealed that transactivation represents only one mode of signalling via the GR and recently the abilities of 5α-reduced GCs to suppress inflammation have been demonstratedin vitroandin vivo. Thus, the balance of parent GC and its 5α-reduced metabolite may critically affect the profile of GR signalling. 5α-Reduction of GCs is up-regulated in liver in metabolic disease and may represent a pathway that protects from both GC-induced fuel dyshomeostasis and concomitant inflammatory insult. Therefore, 5α-reduced steroids provide hope for drug development, but may also act as biomarkers of the inflammatory status of the liver in metabolic disease. With these proposals in mind, careful attention must be paid to the possible adverse metabolic effects of 5α-reductase inhibitors, drugs that are commonly administered long term for the treatment of benign prostatic hyperplasia.
Socket Preservation and Sinus Augmentation Using a Medical Grade Calcium Sulfate Hemihydrate and Mineralized Irradiated Cancellous Bone Allograft Composite
Authors: Bagoff Robert , Mamidwar Sachin , Chesnoiu-Matei Ioana , Ricci John L. , Alexander Harold , Tovar Nick M.
Published: September 2011

Regeneration and preservation of bone after the extraction of a tooth are necessary for the placement of a dental implant. The goal is to regenerate alveolar bone with minimal postoperative pain. Medical grade calcium sulfate hemihydrate (MGCSH) can be used alone or in combination with other bone grafts; it improves graft handling characteristics and particle containment of particle-based bone grafts. In this case series, a 1:1 ratio mix of MGCSH and mineralized irradiated cancellous bone allograft (MICBA) was mixed with saline and grafted into an extraction socket in an effort to maintain alveolar height and width for future implant placement. MGCSH can be used in combination with other bone grafts and can improve handling characteristics and graft particle containment of particle-based bone grafts. In the cases described, we found that an MGCSH:MICBA graft can potentially be an effective bone graft composite. It has the ability to act as a space maintainer and as an osteoconductive trellis for bone cells, thereby promoting bone regeneration in the extraction socket. MGCSH, a cost-effective option, successfully improved MICBA handling characteristics, prevented soft tissue ingrowth, and assisted in the regeneration of bone.
Replacement of Mandibular Posterior Teeth With Implants in a Postmandibular Resection Case: A Case Report
Authors: Christian Jayanth , Grover Manita , Veeravalli Padmanabhan Thallam
Published: September 2011

This case report describes the prosthetic rehabilitation of a patient who was treated for ameloblastoma by segmental resection of the mandible. Because of the size of the defect it was decided to use a healing obturator to facilitate bone formation in the defect. At the end of 3 months, bone formation had led to complete obliteration of the defect with an almost complete fill to the crest of the ridge. The next phase of the treatment was prosthetic rehabilitation. The patient preferred a fixed replacement of teeth as opposed to a removable option. The final treatment plan was an implant-supported fixed prosthesis that was progressively loaded.
Self-regulation of Elite Athletes in China
Authors: Sun Yongjun , Wu Xiufeng
Published: September 2011

The perceived self-regulation of Chinese world-class athletes were examined in this study. Qualitative data from 14 athletes were analyzed by a grounded theory method. The feelings of Chinese elite athletes who achieved either successful or unsuccessful self-regulation were noted. Results
showed that successful self-regulation involved a calm mental state, smooth rhythm in performance, concentration, and flow, whereas rhythmic disorder, stress, mental fatigue, and loss of flow were cited by athletes during unsuccessful self-regulation. Our analysis indicated that a calm mind,
rhythmic preparation, and lack of pressure were the major factors contributing to the maintenance of control. Preparation that was not well-planned and regular, the influence of stress, and mental fatigue did not support successful performance.
Rural to Urban Migration: Evidence of I-lan County Residents
Authors: Chang Shu-Chun
Published: September 2011

In this study 2 key interrelated issues were addressed: the main reasons for out-migration occurring in I-Lan county and the characteristics of out-migrants from I-Lan County to Taipei City. The research design and strategy for data collection employed in this study incorporated 2 representative
sample surveys, the first comprising 200 out-migrants from I-Lan County, and the second 100 stayers who remained in I-Lan County. It was found that increasing income is not the main reason behind migration.
Upgrading of the Management Review on the Basis of the EFQM Excellence Model
Authors: Petrič Anton , Gomišček Boštjan
Published: September 2011

Upgrading of the Management Review on the Basis of the EFQM Excellence Model

Suppliers in the automotive industry can use for strategical planning a number of different approaches and tools, which can upgrade the quality management systems (ISO 9001, ISO/TS 14696) to achieve the breakthrough power to meet needs in order to achieve a significant role in the automotive supplying chain. One of the very popular and positively accepted tools to achieve continually improving is implementing of the principles of excellence, according to the EFQM model.

On the basis of case studies is in the article analysed and represented a useful value of the implementation of the quality management system audits and management review according to ISO/TS and their positive impact on the development of key indicators of the company TPV d.d. from Novo mesto, which is mounted as a development supplier in the automotive industry. With the implementation of self assessment according to the model of excellence EFQM we demonstrate the added value of the take up of the principles of excellence, according to the present system auditing according to ISO standards and the implementation of management review according to ISO/TS requirements.

We upgraded in the existing management system performing of management review as manager's tool, which came directly from the requirements of standard ISO/TS, on to the level of the fundamental principles of excellence by EFQM model and mark it as one of the more effective managers tools with which you can still effectively introduces the leadership of the continuous improvements and strategically manages the company.
Perceived Factors and Obstacles to Cognitive Schema Change during Economic Crisis
Authors: Arzenšek Ana
Published: September 2011

Perceived Factors and Obstacles to Cognitive Schema Change during Economic Crisis

The main objective is to present the perceived factors in cognitive schema change as experienced by participants from two Slovenian sectors and to compare them with factors from schema change theory in order to evaluate specific circumstances and obstacles to effective cognitive schema change. 31 interviews with participants from six companies were conducted twice during the 2008 economic crisis. The prevalent perceived antecedents of schema change lie within an organisation and in the business environment. Stimulating factors are also economic and financial crises and personal characteristics. The prevalent obstacles to schema change, as perceived by participants, are stability of current cognitive schemas, personal characteristics of management, and rigidity.
The effects of feeding fresh forage and silage on some nutritional attributes of beef: an overview
Authors: Kalač Pavel
Published: September 2011

The effects of feeding fresh forage and silage on some nutritional attributes of beef: an overview

Consumers are increasingly concerned with the amount and composition of fat present in foods. The nutritional image of cattle fat has suffered because of the association of a high proportion of saturated fatty acids with coronary heart disease. This is leading to a shift in the way milk and beef are produced. Extensive research data from the last decade show that beef from animals finished on green fodder and silages (except for maize silage) has a lower content of intramuscular fat, but a higher proportion of nutritionally favourable n-3 polyunsaturated fatty acids (PUFAs), ratio n-6:n-3 PUFAs, vitamin E and ß-carotene, than meat from animals fed on grain-based rations. The differences in beef cholesterol content between the feeding systems are not nutritionally significant.
The occurrence of Erysiphe trifolii on Lathyrus pratensis in a foothill area of South Bohemia
Authors: Kobes Milan , Voženílková Bohumila , Šlachta Martin , Frelich Jan
Published: September 2011

The occurrence of Erysiphe trifolii on Lathyrus pratensis in a foothill area of South Bohemia

The aim of small-site experiments carried out in the foothills of the Šumava Mts. was to determine the effect of the etiological agent powdery mildew (Erysiphe trifolii) on meadow peavine (Lathyrus pratensis). Over three consecutive years, we observed a whitish to grey-white soft cover of mycelium on the meadow peavine during the vegetation period. This characteristic symptom of the disease was observed on the plants during summer and autumn. In a plot trial with permanent grassland we evaluated the following management systems: i) mulched, ii) fallow, iii) mown stands, and iv) pasture stands grazed by cattle. We evaluated the total number of Lathyrus pratensis plants as well as the number of the plants attacked by Erysiphe trifolii. The three-year investigation of Lathyrus pratensis yielded statistical evidence that the most significant growth of the fungal disease was recorded in fallow stands (68.9%), while the lowest occurrence of the disease (4.4%) was found in the pasture stands grazed by cattle.
Deployment of an Agent-based SANET Architecture for Healthcare Services
Authors: Chiu Christopher , Chaczko Zenon
Published: September 2011

Deployment of an Agent-based SANET Architecture for Healthcare Services

This paper describes the adaptation of a computational technique utilizing Extended Kohonen Maps (EKMs) and Rao-Blackwell-Kolmogorov (R-B) Filtering mechanisms for the administration of Sensor-Actuator networks (SANETs). Inspired by the BDI (Belief-Desire-Intention) Agent model from Rao and Georgeff, EKMs perform the quantitative analysis of an algorithmic artificial neural network process by using an indirect-mapping EKM to self-organize, while the Rao-Blackwell filtering mechanism reduces the external noise and interference in the problem set introduced through the self-organization process. Initial results demonstrate that a combinatorial approach to optimization with EKMs and Rao-Blackwell filtering provides an improvement in event trajectory approximation in comparison to standalone cooperative EKM processes to allow responsive event detection and optimization in patient healthcare.
Computationally-Efficient Design of a Dynamic System-Level LTE Simulator
Authors: Muñoz Pablo , de la Bandera Isabel , Ruiz Fernando , Luna-Ramírez Salvador , Barco Raquel , Toril Matías , Lázaro Pedro , Rodríguez Jaime
Published: September 2011

Computationally-Efficient Design of a Dynamic System-Level LTE Simulator

The Long-Term Evolution (LTE) is the next generation of current mobile telecommunication networks. LTE has a new flat radio-network architecture and a significant increase in spectrum efficiency. In this paper, a computationally-efficient tool for dynamic system-level LTE simulations is proposed. A physical layer abstraction is performed to predict link-layer performance with a low computational cost. At link layer, there are two important functions designed to increase the network capacity: Link Adaptation and Dynamic Scheduling. Other Radio Resource Management functionalities such as Admission Control and Mobility Management are performed at network layer. The simulator is conceived for large simulated network time to allow evaluation of optimization algorithms for the main network-level functionalities.
Traveler Information Tool with Integrated Real-Time Transit Information and Multimodal Trip Planning
Authors: Zhang Liping , Li Jing-Quan , Zhou Kun , Gupta Somak Datta , Li Meng , Zhang Wei-Bin , Miller Mark A. , Misener James A.
Published: September 2011

The chief objective of the PATH2Go multimodal traveler information application is to improve the accessibility and the quality of real-time traveler information and to make transit a known and viable choice for travelers. PATH2Go was developed as part of a field test on the US-101 corridor in the San Francisco Bay Area of California, with the primary hypothesis that travelers would benefit from real-time multimodal traveler information and therefore would be likely to consider using transit. PATH2Go integrates a web-based multimodal trip-planning tool that uses real-time transit, traffic, and parking information; a web-based search tool that finds real-time information about transit arrivals and schedules; and a mobile application that provides personalized en route transit trip information. PATH2Go integrates these major components of traveler information in one platform and makes real-time information easily accessible to travelers. The PATH2Go system architecture and major design considerations are described, and enabling technologies–including the Global Positioning System (GPS) fusing algorithm and a scenario-parsing algorithm based on GPS location data–are introduced.
Development of Web-Based Analysis System for Real-Time Decision Support on Arterial Networks
Authors: Wu Yao-Jan , An Shi , Ma Xiaolei , Wang Yinhai
Published: September 2011

With increasing amounts of data being collected for intelligent transportation systems on arterial networks, the archival, management, and analysis of complex network traffic data have become a challenge. Challenges include inconsistent data connections, data quality control, query performance, traffic prediction, and computational limitations. The web-based RADAR Net system is presented to address these challenges. This system adopts a relational database with link, intersection, and detector entities. Relational data demonstrate its query performance and scalability. The system contains four layers: offline server, online server (middleware), online server (Java Servlet), and online client. This four-layer design successfully distributes the computational burden on the server. To monitor arterial performance, link speeds are calculated directly from loop detector data retrieved in Bellevue, Washington. The system can dynamically predict and smooth real-time loop spot speeds by using an alpha-beta filter (a simplified version of the Kalman filter) while maintaining high system performance. The link speeds of the entire network are calculated and updated in real time. Many application modules (e.g., for capacity analysis and dynamic routing) based on the system architecture have been implemented and have proven the system feasible for performing real-time analysis and assisting decision making.
DRIVE Net
Authors: Ma Xiaolei , Wu Yao-Jan , Wang Yinhai
Published: September 2011

In past decades, transportation research has been driven by mathematical equations and has relied on scarce data. With increasing amounts of data being collected from intelligent transportation system sensors, data-driven or data-based research is expected to expand soon. Most online systems are designed to handle one type of data, such as from freeway or arterial sensors. Even if transportation data are ubiquitous, data usability is difficult to improve. A framework is proposed for a regionwide web-based transportation decision system that adopts digital roadway maps as the base and provides data layers for integrating multiple data sources (e.g., traffic sensor, incident, accident, and travel time). This system, called the Digital Roadway Interactive Visualization and Evaluation Network (DRIVE Net), provides a practical method for facilitating data retrieval and integration and enhances data usability. Moreover, DRIVE Net offers a platform for optimizing transportation decisions that also serves as an ideal tool for visualizing historical observations spatially and temporally. Not only can DRIVE Net be used as a practical tool for various transportation analyses, with the use of its online computation engine, DRIVE Net can also help evaluate the benefit of a specific transportation solution. In its current implementation, DRIVE Net demonstrates potential to be used soon as a standard tool to incorporate more data sets from different fields (e.g., health and household data) and offer a platform for real-time decision making.
Uncertainty Issues in Integrating Geographic Information Systems and the Global Positioning System for Transportation
Authors: Hong Sungchul , Vonderohe Alan P.
Published: September 2011

The Global Positioning System (GPS) and geographic information systems (GIS) have been integrated for a wide range of transportation applications. When a linear datum is not implemented into the applications, a route measure is indirectly determined with snapped GPS-derived coordinates along roadway centerlines. Thus, uncertainties in output information are subject to various types of error and error sources in GPS and roadway centerline maps and their propagation through spatial operations. A method for uncertainty analysis is presented. The method estimates the quality of output information from GPS- and GIS-integrated applications for transportation. The method involves an analytical GPS error model and an error propagation model, assuming that a test roadway centerline map is representative of roadway centerline maps with the same nominal scale. In the case study, the method was applied to a winter maintenance application and a travel time study. The optimum input data set for each application was determined by sensitivity analysis that explored the impact of positional uncertainties on variations of output information computed from distance-based and non-distance-based computation models. Results indicated that the winter maintenance application required accurate input data because uncertainties in output information were accumulated as winter maintenance vehicles repeatedly treated roadways. However, for the travel time study, consistent output information was computed with a minute level of accuracy, so positional uncertainties in input data had a negligible impact on output information.
Protecting Location Privacy
Authors: Cottrill Caitlin , Thakuriah Piyushimita
Published: September 2011

With the growing trend toward location-based services in transportation, the collection and the use of traveler data have grown rapidly. With the potential for multiagency sharing of data and an increased public-private partnerships, inconsistencies in how data are collected and shared may become of growing concern for users, particularly given the potential sensitivity of locational data. An overall picture of policies relevant to data collection and use in the private locational environment highlights the gaps that may be evident between the privacy recommendations of regulatory and industry guidance agencies and individual company policies. The approach combines policy and content analysis to determine how well identified privacy considerations are reflected in user-oriented privacy policies.
Driver Comprehension and Assessment of Traffic Control Devices at Signalized Intersections Interfacing with Light Rail Transit
Authors: Pecheux Kelley Klaver , Golembiewski Gary A.
Published: September 2011

Signalized intersections that interface with light rail transit (LRT) pose a unique challenge to traffic operations and safety. Although progress toward mitigating light rail vehicle–motor vehicle crashes has been made, many agencies still face safety issues at these intersections. Few empirical studies of the effectiveness of the safety measures currently being used have been conducted. Safety measures have not been tested with drivers; rather, the measures they have evolved over time through practice. The objectives of this research were to assess driver comprehension and to explore drivers’ perceptions and opinions of a variety of traffic control devices (TCDs) that were or that might be used at signalized intersections that interface with LRT. The research approach was to present simulated scenes to drivers with a variety of intersection scenarios and TCDs in a focus group setting. The results showed that drivers had preferences for TCDs at these intersections. Although existing TCDs are understood and generally liked, ongoing issues with safety suggest that improvements can still be made. The use of green arrow signal displays or supplemental pavement markings could improve driver situational awareness at some intersections. Enhancements to the existing Manual on Uniform Traffic Control Devices W10-7 (i.e., train icon) activated blank-out sign, such as adding the word “train” or alternating the train icon with the no left turn icon, could result in increased driver compliance. Finally, providing an active warning device on the cross street, such as the W10-7 sign, could increase safety by making drivers and pedestrians more aware of the arrival of a train.
Light Rail Systems Free of Overhead Wires
Authors: Novales Margarita
Published: September 2011

Light rail systems are experiencing a revival in several countries in the world. Nevertheless, light rail systems are facing a more demanding market and by implication the need for continuous evolution and new technologies. An example of this need is related to the requirement of avoiding visual intrusion in some areas of cities that are more sensitive to visual impacts. This sensitivity has led to the implementation of new solutions that try to avoid the need for overhead contact wires throughout the whole network or throughout the distances between stations. These solutions are generally based on the use of new systems with an embedded third rail, onboard energy storage devices, or electrical energy produced on board the vehicle. This paper explains these technologies and their applicability, as well as their advantages, risks, and inconveniences, in an attempt to clarify the available options and their reliability.
Context-Sensitive Design Concepts for Streetcar Electrification
Authors: Boorse Jack W. , Meade Monica J.
Published: September 2011

As the interest in establishing new streetcar systems in various cities throughout the United States continues, concerns over the possible visual impact of the overhead wiring are sometimes expressed. These concerns are not without basis. In some cases the genesis of such concern is the trend to use catenary rather than traditional trolley wire on light rail transit lines. Catenary is unavoidably conspicuous. In addition to the contact wire, catenary comprises a thick messenger cable with multiple vertical hangers to support the contact wire and other appurtenances, all out over the middle of the street. The use of catenary in a street setting is a departure from traditional streetcar track electrification, which generally has only a single wire over the track. These concerns about the visual impact can be particularly acute at specific locations, such as where a line segment is bordered by a grand or historic edifice or is in a park setting. This is the case at particular locations in Washington, D.C., and San Diego, California, where the desire is to avoid even unobtrusive wiring. The time is propitious for a revisitation of overhead wire design concepts as an element in addressing visual impact concerns. This paper discusses the engineering designs that are available to satisfy these two needs, which are (a) electrification of the primary trackage of a network with minimal visual impact and (b) feasible onboard power storage to allow operation on nonelectrified track segments in zones where a total absence of overhead wire is considered essential.
Transit Ridership Evaluation Using Aggregate-Level Causal Analyses of Subway Mode Shares in Seoul, South Korea
Authors: Ko Joonho , Park Dongjoo , Lee Sehee
Published: September 2011

Adequate evaluations of transit system efficiency in direct connection with environmental concerns and the economic aspects of the city are critical for development of a better system. This paper presents an evaluation framework by comparing the subway mode shares of 25 districts in Seoul, South Korea. In this effort, causal relationships between the inherent conditions of the district and the resultant mode shares were identified on the basis of regression models with independent variables indicating the system supply level. The expected mode shares from the regression model and the actual shares were then compared as a way to identify districts displaying relatively higher or lower subway mode shares. These processes revealed key influential factors affecting subway mode share and suggest that the system supply level is strongly related to mode share and that ridership increases may be achieved by providing convenient access to stations. The implications of this study are expected to shed light on potential policy actions to improve transit ridership, particularly for those districts with relatively lower levels of ridership.
Regional Rapid Transit
Authors: Allen John G. , Levinson Herbert S.
Published: September 2011

Traditional rail rapid transit systems are primarily limited to central cities, but a modern variant, regional rapid transit (RRT), extends far enough into suburbs to be considered truly regional in scope. RRT uses automatic train driving, other advanced technologies, long station spacing, and park-and-ride lots to serve suburban as well as city travel. Inaugurated between 1969 and 1979, RRT operations in several regions (Philadelphia, Pennsylvania; Boston, Massachusetts; San Francisco, California; Washington, D.C.; and Atlanta, Georgia) combined advanced rapid transit technology with station spacing and market functions akin to inner-zone to midrange commuter rail. To establish similarities and differences between the properties of RRT and other rail systems, data are analyzed for these and other rapid transit systems, as well as for historically established commuter railroads. RRT operations today face challenges of aging infrastructure but continue to be vital in the areas that they serve and have undergone incremental expansion in some instances.
Moving toward Unrestricted Shared Use
Authors: DiBrito Dominic A. , Mayville Ronald A. , Doty Robert , Tsao Camille
Published: September 2011

This paper describes the process that the Peninsula Corridor Joint Powers Board (Caltrain) in California used to obtain a waiver of FRA crashworthiness regulations to allow the operation of European-style electric multiple units (EMUs) commingled with FRA-compliant passenger trains. It presents the five basic components of the waiver petition, provides details about the safety features of the European-style EMUs, and summarizes the lessons learned during the 3-year process. Operating non-FRA-compliant European-style EMUs commingled with FRA-compliant locomotive-hauled passenger trains will not compromise Caltrain's safety and the measures to be put in place as conditions of the waiver will enhance the overall safety of the system.
Investigation of Portland Cement Concrete Exposed to Automated Deicing Solutions on Colorado's Bridge Decks
Authors: Truschke Carol , Peterson Karl , Van Dam Thomas , Peshkin David , DeDene Christopher , DeDios Roberto
Published: September 2011

The Colorado Department of Transportation (DOT) has identified potential performance problems in some portland cement concrete (PCC) bridge decks and approach slabs in the form of pattern surface cracking, spalling, and joint and crack deterioration; these problems are suspected to be materials-related distress (MRD). External factors such as deicing and anti-icing chemicals can initiate and increase the rate and magnitude of deterioration caused by MRD and thereby shorten the life of the structure. This study investigated whether highly concentrated deicer solutions that were applied through bridge deck deicing and anti-icing systems that used fixed automated spray technology disproportionately contributed to deterioration of PCC bridge decks and adjacent concrete approach slabs in Colorado and whether mitigation strategies employed by Colorado DOT addressed the problem. The investigation involved visual inspection techniques, materials sampling, and evaluation of sampled concrete by using petrographic methods. In bridge decks studied, the concrete evaluated seemed sufficiently resistant to damage from the intrusion of deicer chemicals. Where full-depth cracking was present, however, obvious signs of the movement of moisture and deicers through the deck were observed. Also, some initial signs of possible chemical attack from deicers were noted, and continued exposure to highly concentrated deicers may have contributed to long-term durability concerns. However, use of polymer-modified asphalt and fabric membranes in conjunction with a hot-mix asphalt overlay seemed effective in preventing the ingress of chlorides into the underlying concrete deck.
Health Monitoring of Prestressing Tendons in Posttensioned Concrete Bridges
Authors: Salamone Salvatore , Bartoli Ivan , Phillips Robert , Nucera Claudio , di Scalea Francesco Lanza
Published: September 2011

Currently 90% of bridges built in California are posttensioned box girder. In such structures, the steel tendons are the main load-carrying components. The loss of prestress, as well as the presence of defects or tendon breakage, can be catastrophic for the entire structure. No well-established method monitors prestressing tendons that can provide simultaneous information related to the presence of defects and the level of prestress in a continuous, real-time manner. If such a monitoring system were available, considerable savings would be achieved in bridge maintenance because repairs would be implemented in a timely manner without traffic disruptions. This paper presents a health-monitoring system for prestressing tendons in posttensioned structures of interest to the California Department of Transportation. Such a system uses guided ultrasonic waves and embedded sensors to measure the level of applied prestress and to detect defects at early growth stages simultaneously and in real time. The results of tests on a large-scale, single-tendon posttensioned joint specimen, subjected to multiple load cycles, are presented to validate the monitoring of prestress loads (through nonlinear ultrasonic probing) and the monitoring of damage progression and location (through acoustic emission techniques).
Evaluating Methods and Algorithms for Multicriteria Bridge Management at the Network Level
Authors: Patidar Vandana , Labi Samuel , Morin Thomas , Thompson Paul D. , Sinha Kumares C.
Published: September 2011

In the current era of greater stakeholder participation, limited funding, and increased user awareness, bridge managers are using multiple-criteria techniques in their decision-making processes so that their decisions can be more accountable and transparent. Issues that arise in making such decisions include the multiplicity of the performance criteria and associated decision constraints and the large bridge inventories in most states. These issues translate into increased problem dimensionality, many variables, and excessive computational time. This paper presents alternative formulations and methods for decision problems, identifies alternative algorithms for implementing the solutions, and evaluates the performance of the algorithms. The algorithms include the incremental utility–cost ratio (IUC), Lagrangian relaxation, and pivot and complement methods. In investigating the suitability of these algorithms for agencywide bridge management, the study carried out computational experiments with field data. The criteria for evaluating the performance of the algorithms were computational speed, accuracy, simplicity, and robustness. The results were unequivocal: of the three heuristics, IUC consistently performed the best. IUC provided the simplest and quickest way to compute the optimal solution when small changes were made to the input parameters without the need to redo the entire optimization for each budget level.
Effect of Initial Timing of Scarification and Overlay Treatment on Chloride Concentrations in Concrete Bridge Decks
Authors: Guthrie W. Spencer , Nolan Curtis D. , Bentz Dale P.
Published: September 2011

Scarification and overlay (SO) procedures are often performed on concrete bridge decks to minimize the corrosion of reinforcing steel caused by chloride ingress. The objectives of this research were to collect information from personnel of state departments of transportation (DOTs) about their SO procedures and to recommend the timing of initial SO procedures on concrete bridge decks to prevent the accumulation of corrosion-inducing levels of chlorides and to extend deck service life. A survey of state DOTs was conducted; numerical modeling of SO treatments was performed for decks both with and without stay-in-place metal forms (SIPMFs). Full-factorial numerical modeling was performed through a service life of 50 years to determine the recommended initial timing of SO treatment in each case. Research results showed that bridge decks without SIPMFs could endure longer delays in SO treatment timing than those with SIPMFs. The allowable delay in SO timing ranged from 2 years to 6 years for decks with SIPMFs, while the allowable delay ranged from 6 years to 18 years for decks without SIPMFs. In addition, results showed that the allowable delay also depended on the original cover depth (OCD). On average, for each additional 0.5 in. (12.7 mm) of OCD, the period of additional allowable delay for decks with SIPMFs was 2 years; for decks without SIPMFs, however, the additional allowable delay was 5 years with each additional 0.5 in. (12.7 mm) of OCD.
Effects of Concrete Mix on Initiation of Reinforcement Corrosion and Chloride Threshold Level
Authors: Yu Hui , Lu Baotong , Presuel-Moreno Francisco , Zheng Wei
Published: September 2011

The time-to-corrosion initiation (Ti) of reinforcement and the chloride threshold content (Cth) of a series of G109 concrete slabs were experimentally investigated. Results indicate that Ti is increased by decreasing water-to-cement ratio or increasing cement alkalinity. The effects of a superplasticizer on initiation of corrosion of reinforcing steel bars (rebar) depend on concrete mix. Measurements reveal that chloride contents at both active (anodic) and passive (cathodic) sites increase linearly with the logarithm of Ti regardless of concrete mix, whereas chloride contents measured at anodic sites are always greater than at cathodic sites. Defects at or nearby corrosion anodic spots could facilitate chloride accumulation: rebar corrosion would occur earlier than if no defect were present. Further analysis reveals that the weakest-link theory is applicable to predict the probability of initiation of rebar corrosion, as indicated by the Weibull distributions of Ti and Cth.
Evaluation of Light-Emitting Diode Warning Beacons for Maintenance Vehicles
Authors: Bullough John D. , Skinner Nicholas P.
Published: September 2011

Rotating warning beacons containing filament light sources have long been used on highway maintenance vehicles to indicate the presence of the vehicle to other drivers. Flashing warning beacons containing light-emitting diodes (LEDs) are beginning to be used in place of rotating warning beacons, in part because they use considerably less power. To help ensure that LED warning beacons will provide a comparable warning signal to drivers who approach vehicles outfitted with them, the photometric and temporal characteristics of LED warning beacons were measured and compared with data on human response time. In addition, several LED warning beacons were compared with a conventional incandescent rotating warning beacon in regard to the distance at which observers could detect that a vehicle had moved closer. Pairs of LED warning beacons provided closure detection distances that were equivalent to pairs of conventional rotating beacons. Although single LED warning light configurations were not tested, the pairs of LED beacons that were tested reliably outperformed a single conventional beacon configuration for both energy use and closure detection distance. Results suggested that LED warning beacons provide comparable visual information to other drivers and use substantially less power than conventional rotating beacons do.
Equipment Replacement Optimization
Authors: Fan Wei (David) , Machemehl Randy B. , Kortum Katherine
Published: September 2011

This paper provides a comprehensive literature review of the state of the art and state of the practice of equipment replacement optimization (ERO). A comprehensive dynamic programming (DP)–based optimization solution methodology is then proposed and implemented for ERO. The developed ERO software consists of three main components: a SAS macro-based data cleaner and analyzer, which undertakes the tasks of raw data reading, cleaning, and analyzing, as well as cost estimation and forecasting; a DP-based optimization engine that minimizes the total cost over a defined horizon; and a Java-based graphical user interface (GUI) that takes parameters selected by users and inputs from users, and coordinates the optimization engine and SAS macro-based data cleaner and analyzer. The first component (i.e., the SAS macro-based data cleaner and analyzer) is presented in detail. Preliminary numerical results of the SAS data analysis, estimation, and forecasting of several costs are also discussed. In a later report of research, the DP-based optimization engine and ERO software development (including the Java GUI) will be presented in detail, and comprehensive ERO numerical results will be given.
Reducing hemorrhagic complications in functional neurosurgery: a large case series and systematic literature review
Authors: Zrinzo Ludvic , Foltynie Thomas , Limousin Patricia , Hariz Marwan I.
Published: September 2011

Object

Hemorrhagic complications carry by far the highest risk of devastating neurological outcome in functional neurosurgery. Literature published over the past 10 years suggests that hemorrhage, although relatively rare, remains a significant problem. Estimating the true incidence of and risk factors for hemorrhage in functional neurosurgery is a challenging issue.

Methods

The authors analyzed the hemorrhage rate in a consecutive series of 214 patients undergoing imageguided deep brain stimulation (DBS) lead placement without microelectrode recording (MER) and with routine postoperative MR imaging lead verification. They also conducted a systematic review of the literature on stereotactic ablative surgery and DBS over a 10-year period to determine the incidence and risk factors for hemorrhage as a complication of functional neurosurgery.

Results

The total incidence of hemorrhage in our series of image-guided DBS was 0.9%: asymptomatic in 0.5%, symptomatic in 0.5%, and causing permanent deficit in 0.0% of patients. Weighted means calculated from the literature review suggest that the overall incidence of hemorrhage in functional neurosurgery is 5.0%, with asymptomatic hemorrhage occurring in 1.9% of patients, symptomatic hemorrhage in 2.1% and hemorrhage resulting in permanent deficit or death in 1.1%. Hypertension and age were the most important patient-related factors associated with an increased risk of hemorrhage. Risk factors related to surgical technique included use of MER, number of MER penetrations, as well as sulcal or ventricular involvement by the trajectory. The incidence of hemorrhage in studies adopting an image-guided and image-verified approach without MER was significantly lower than that reported with other operative techniques (p < 0.001 for total number of hemorrhages, p < 0.001 for asymptomatic hemorrhage, p < 0.004 for symptomatic hemorrhage, and p = 0.001 for hemorrhage leading to permanent deficit; Fisher exact test).

Conclusions

Age and a history of hypertension are associated with an increased risk of hemorrhage in functional neurosurgery. Surgical factors that increase the risk of hemorrhage include the use of MER and sulcal or ventricular incursion. The meticulous use of neuroimaging—both in planning the trajectory and for target verification—can avoid all of these surgery-related risk factors and appears to carry a significantly lower risk of hemorrhage and associated permanent deficit.
Subarachnoid hemorrhage due to retained lumbar drain
Authors: Guppy Kern H. , Silverthorn James W. , Akins Paul T.
Published: September 2011

Intrathecal spinal catheters (lumbar drains) are indicated for several medical and surgical conditions. In neurosurgical procedures, they are used to reduce intracranial and intrathecal pressures by diverting CSF. They have also been placed for therapeutic access to administer drugs, and more recently, vascular surgeons have used them to improve spinal cord perfusion during the treatment of thoracic aortic aneurysms. Insertion of these lumbar drains is not without attendant complications. One complication is the shearing of the distal end of the catheter with a resultant retained fragment. The authors report the case of a 65-year-old man who presented with a subarachnoid hemorrhage due to the migration of a retained lumbar drain that sheared off during its removal. To the best of the authors' knowledge, this is the first case of rostral migration of a retained intrathecal catheter causing subarachnoid hemorrhage. The authors review the literature on retained intrathecal spinal catheters, and their findings support either early removal of easily accessible catheters or close monitoring with serial imaging.