bluuebunny/crossref_metadata_2025 huggingface dataset:
Methodology for Checking Shortcomings in Three-Dimensional Alignment
Authors: Kuhn Wolfgang , Jha Manoj K.
Published: February 2012

Road design by highway planning authorities and planning offices is performed at three separate levels: the horizontal and the vertical projections and the cross section. Experiments have shown that shortcomings in the three-dimensional (3-D) alignment may still occur when these three levels are processed separately and then superimposed. It makes sense to calculate virtual perspective views and special control parameters with the use of visualization tools and then to check the 3-D alignment with those tools. Shortcomings of this kind can cause accidents, particularly on two-lane rural roads. Unified model assumptions that match the driver's vision must be set to ensure the comparability of the central perspective views. Drivers absorb images from a central perspective when driving along a road. A driver's inability to recognize a section of the road in the driving area ahead gives rise to blind sections. Designers need to use standard 3-D elements as much possible. These shortcomings are of two major types: those that are safety related and those that are merely aesthetic. A methodology has been developed to check the 3-D alignment for shortcomings in the three basic stages (checking for standard 3-D elements, safety-related shortcomings, and aesthetic shortcomings). By using the visualization tool VISS ALL 3D, the design engineer can calculate the virtual perspective views with the safety-related shortcomings and illustrate them in the blind-section graph. Shortcomings in the 3-D alignment must be eliminated at the end of the redesign process.
Provision of Sight Distance around Concrete Barriers and Structures on Freeways and Interchanges
Authors: Arndt Owen K. , Cox Ricky L. , Lennie Sandra C. , Whitehead Mike T.
Published: February 2012

The use of concrete barriers 1.1 m (3.6 ft) high at both median and outer-shoulder edges of freeways is common in Australia. The use of such barriers is also common on interchange ramps on or under structures. Where curved ramps form an overpass of a major road or a road crosses a rail line, concrete barriers 1.4 m (4.6 ft) high and larger are used. The provision of criteria for normal stopping sight distance around these concrete barriers and other structures such as bridge abutments and retaining walls on horizontal curves (and on combinations of horizontal and vertical curves) can lead to a requirement for extremely wide shoulders. Such shoulder widths were often considered uneconomical, and only narrow shoulders were provided. This choice was either based on some artificially low design speed or, even worse, was made by ignoring the sight distance requirements altogether and simply providing what was considered to be practical. This paper discusses new criteria for the provision of sight distance around barriers and structures, as documented in the 2009 release of the Austroads Guide to Road Design series. The new criteria achieve practical, yet justifiable, results.
New Insights on Evaluations of Design Consistency for Two-Lane Highways
Authors: Himes Scott C. , Donnell Eric T. , Porter Richard J. (R. J.)
Published: February 2012

Operating speed prediction models along horizontal curves of two-lane rural highways have been the topic of a significant body of literature. Operating speed models for two-lane rural highway tangents and for horizontal curves on low-speed urban streets also exist but are less developed. These models, estimated primarily by means of ordinary least squares regression, generally use aggregate-level data to estimate the effect of geometric design variables on the mean or 85th percentile operating speed but do not explicitly consider measures of speed dispersion (e.g., standard deviation). Most existing models consider speeds of free-flow passenger vehicles; traffic flow effects on speed are generally not quantified. Finally, published literature shows that researchers have not converged on a consistent modeling practice about the use of posted speed limit as an explanatory variable in operating speed models. Collectively, these issues may lead to design consistency assessments that are not truly reflective of the operating conditions along a two-lane highway. These issues are explored in this paper with the use of operating speed data collected at multiple points along eight two-lane highway segments. A simultaneous equations approach is used to estimate a three-equation model of the posted speed limit, mean speed, and speed deviation. The predicted 85th percentile speed is compared with the observed 85th percentile speed along a high-speed, two-lane rural highway. Predicted 85th percentile operating speeds along the same high-speed highway determined with the Interactive Highway Safety Design Model design consistency module are also compared with observed 85th percentile speeds as a basis for evaluating the simultaneous equations approach. Finally, the paper proposes an alternative approach to evaluating design consistency that uses inferred design speed.
Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data
Authors: Llorca Carlos , García Alfredo
Published: February 2012

Drivers need sufficient passing sight distance (PSD) to pass slower vehicles with safety. This distance can help to improve traffic operation on two-way, two-lane highways. Existing models propose different values of PSD because of different assumptions. In only some cases were these models based on field data of passing maneuvers. This research proposed the design of a methodology to observe passing maneuvers on existing highways with the help of six video cameras installed at a fixed point next to passing sections. The use of more cameras allows complete registration of trajectories along the entire passing zone, with uniform image resolution. The methodology was applied to register a sample of 234 maneuvers on four passing zones. Trajectories of 58 maneuvers were completely described and analyzed with specific restitution software. Results were compared with those from existing PSD models. The distances traveled proposed by the AASHTO model on the left lane were (a) similar to average observed distances when the passed vehicle was one truck and (b) between 50 and 100 m higher when one passenger car was passed. Higher differences, greater than 100 m, were found between measured data and the PSD model (published previously), especially at high design speeds. The observed average speed difference between passing and impeding vehicles was significantly higher than that in any model. Variables with the strongest influence on the time and distance traveled on the opposing lane were the type and speed of the passed vehicle and the length of the passing zone. Left-lane time and distance increase with this length.
Reduced-Conflict Intersection
Authors: Eyler Dennis R.
Published: February 2012

The selection of the appropriate geometry and traffic control for intersections on high-speed arterial highways often requires balancing increased highway user costs with attempts to control construction costs. Providing a safe design that is cost-effective is always a primary consideration in deciding on a solution. Another issue is that one form of intersection and traffic control may be optimal during peak traffic times on an average day but may not have sufficient capacity for extreme peak times such as those for events or on recreational routes. Alternatively, those same controls can cause needless delay when traffic is lighter. Examples include traffic signals that operate 24 h/day and roundabouts that require all traffic to slow dramatically, regardless of the amount of conflicting traffic. This study presents a group of new alternative intersection designs designated as reduced-conflict intersections. This study describes those designs and their associated traffic control, which consists of a demand-based traffic signal system. This study then presents the results of a comparative analysis of this new type of intersection along with other designs, including a conventional intersection with signal control, two forms of roundabouts, and the super street intersection. The results of the study show that the reduced-conflict intersection may be an effective addition to the toolbox of intersection designs.
Analysis of Operational Interactions between Freeway Managed Lanes and Parallel, General Purpose Lanes
Authors: Liu Xiaoyue , Schroeder Bastian J. , Thomson Timothy , Wang Yinhai , Rouphail Nagui M. , Yin Yafeng
Published: February 2012

Roadway agencies face growing challenges to expand freeway capacity. Under the constraints of rising construction costs, right-of-way limitations, and environmental regulations, transportation agencies are seeking solutions for efficiently managing the demand on existing freeway facilities and for providing options for travelers. The concept of managed lanes (MLs) is an increasingly popular countermeasure that aims to make the most efficient use of freeway facilities by restricting access to one or more lanes to certain vehicle classes on a facility that is parallel to existing general purpose (GP) lanes. With different strategies for separating ML and GP lanes, this study examines the interaction between GP lanes and ML operations. It scrutinizes this interaction as a function of different separation types, the number of MLs, and operational ML strategies, including high-occupancy toll (HOT) and high-occupancy vehicle (HOV) lanes. Four freeway sites were selected to explore the effect of this interaction. The research shows that, for HOT facilities, separation type has the most significant impact on explaining the intensity of the frictional effect, as paint-separated ML facilities are readily affected by congestion in adjacent GP lanes. For HOV facilities, the frictional effect was observed by adopting a stochastic approach to capacity estimation to estimate the capacity distribution function for both GP and HOV lanes. It was determined that GP lanes had a stochastic dominance over HOV lanes under any breakdown probability. The results make the case that ML operations should not be evaluated independently of adjacent GP lanes, and these results have implications for both proposed analytical approaches and simulation-based analyses.
New Three-Dimensional Highway Design Methodology for Sight Distance Measurement
Authors: Jha Manoj K. , Karri Gautham Anand Kumar , Kuhn Wolfgang
Published: February 2012

The traditional two-stage highway design process provides separate processing of horizontal and vertical alignments. One drawback of the two-stage methodology, however, is design inconsistency because of drivers' responses that are not detected until the road is built. To remedy this situation, a three-dimensional (3-D) design methodology has been developed to eliminate the need for postchecking to ensure design consistency and availability of adequate sight distance. With the proposed 3-D design methodology, planners and designers can simulate the entire design process at the onset. The paper presents a novel 3-D algorithm for calculating sight distance on the basis of the proposed 3-D design methodology. A case study demonstrates the applicability of the methodology.
Bridge Rail and Approach Railing for Low-Volume Roads in Iowa
Authors: Bigelow Jake , Hans Zachary , Phares Brent
Published: February 2012

Bridge rail and approach guardrails provide safety to drivers by shielding more-hazardous objects and redirecting vehicles to the roadway. However, guardrails increase both the initial and maintenance costs of a bridge while adding another object that vehicles may strike. According to current reports, most existing bridges for low-volume roads (LVRs) in the state of Iowa do not have bridge rails that meet current standards. The primary objective of this research was to provide information about bridge rail and approach guardrail on LVRs in Iowa. In support of this objective, statewide descriptive, statistical, and economic crash analyses were performed. The statewide crash analysis found that the overall number of crashes at or on the more than 17,000 inventoried and other noninventoried LVR bridges in Iowa during an 8-year period was fewer than 350, a number that represents less than 0.1% of the statewide reportable crashes. Statistical analysis showed that the frequency of vehicle crashes was higher on bridges with a smaller width in relation to the roadway width. The frequency of crashes appeared to be overrepresented at night or in dark conditions. Systemwide, benefit–cost analyses yielded extremely low benefit–cost ratios for statewide bridge rail improvements. However, specific sites where safety concerns exist should be addressed. Overall, each bridge and its crash history should be evaluated independently to determine beneficial safety impacts.
Nonblocked Midwest Guardrail System for Wire-Faced Walls of Mechanically Stabilized Earth
Authors: Lechtenberg Karla A. , Faller Ronald K. , Rohde John R. , Sicking Dean L. , Reid John D.
Published: February 2012

Wire-faced walls of mechanically stabilized earth (MSE) provide an economical method for building vertical structures for supporting roadways where local topography or high land costs preclude the use of conventional fill slopes. W-beam guardrail systems are often used for shielding high vertical drop-offs associated with MSE walls. For this study, the Midwest Guardrail System (MGS) was modified to decrease the overall width of the MSE wall structure. Dynamic component testing was used to determine the post–soil behavior of steel and wood posts embedded in compacted soil materials used for constructing wire-faced MSE walls as well as to evaluate the effects of sloped terrain and different installation methods. Twenty-six dynamic tests were performed to evaluate the propensity for MSE wall damage, to select post length, and to determine the preferred post material and section. The standard MGS was modified by removing the wood spacer blocks 12 in. (305 mm) deep and by incorporating W-beam backup plates. All other MGS features—including the W6 × 8.5 (W152 × 12.6) steel posts 6 ft (1.8 m) long, rail splices at midspan locations, the 31-in. (787-mm) top-mounting height, and the 75-in. (1,905-mm) post spacing—were maintained. The nonblocked MGS was installed with the posts driven at the slope break point of a 3H:1V fill slope. The modified MGS was successfully crash tested with both 1100C small car and 2270P pickup truck vehicles in accordance with Test Level 3 safety performance guidelines in the Manual for Assessing Safety Hardware. The MSE wall was not damaged during the testing programs. The nonblocked MGS is recommended for use with wire-faced MSE walls when they are placed at the slope break point of a 3H:1V fill slope. The modified MGS reduces the required width of the MSE wall, resulting in decreased construction costs.
Design and Testing of Two Bridge Railings for Transverse Nail-Laminated Timber Deck Bridges
Authors: Mongiardini Mario , Rosenbaugh Scott K. , Faller Ronald K. , Reid John D. , Bielenberg Robert W. , Sicking Dean L.
Published: February 2012

Nail-laminated timber deck bridges represent an economical and convenient solution for rural low-volume roads, but a need exists to develop effective railing systems for this type of roadway structure. This paper describes the development of two bridge railings that are specifically designed for transverse nail-laminated timber deck bridges and that meet the requirements for Test Level 1 (TL-1) of the Manual for Assessing Safety Hardware (MASH) and TL-2 of NCHRP Report 350. The design for each of the railing systems was based on retrofit modifications applied to existing bridge railings that were previously successfully tested: one for a longitudinal glue-laminated timber deck and the other for a transverse glue-laminated timber deck. For both railing systems, component testing was performed to investigate the behavior of the proposed design and the potential advantage of various solutions. A full-scale crash test assessed the safety performance of the TL-1 curb-type railing under the new MASH criteria, while dynamic component tests were deemed sufficient for the assessment of the steel railing under TL-2 conditions for NCHRP 350.
Short-Radius Guardrail System for NCHRP Report 350 Test Level 2 Conditions
Authors: Abu-Odeh A. , Kim K.-M. , Bligh R.
Published: February 2012

When a road or driveway intersects a highway with certain restrictive features (bridge rail, culvert, etc.), it is difficult to fit the proper guardrail length (transition, length-of-need guardrail, and end treatment) along the primary roadway. Site constraints such as private driveways, state roads, and parish or county roads may intersect the primary road and prohibit the placement of a properly designed guardrail of the length needed. In these cases, the alternatives are to shorten the designed guardrail length, to relocate the constraint that is blocking placement of the guardrail, and to provide a curved or T-intersection guardrail design. This curved guardrail system is usually known as a short-radius guardrail. This paper investigated the performance of previously tested short-radius guardrail systems to determine whether some of those guardrail systems met NCHRP Report 350 Test Level 2 (TL-2) evaluation criteria. A system designed and tested for Yuma County, Arizona, was adapted as the basis for developing a short-radius guardrail system that satisfies NCHRP Report 350 TL-2 criteria. From an engineering review of previous designs, a recommended short-radius guardrail system that satisfied NCHRP Report 350 TL-2 conditions was developed. The nose section of this system consists of a 3.82-m (121/2-ft) curved W-beam segment that has a 2.44-m (8-ft) radius. This curved section is mounted on breakaway controlled-release terminal posts.
Effect of Barrier Type on Injury Severity in Motorcycle-to-Barrier Collisions in North Carolina, Texas, and New Jersey
Authors: Daniello Allison , Gabler Hampton C.
Published: February 2012

Motorcycle collisions with barriers have been shown to be much more severe than other vehicle collisions with barriers. The impact of barrier type on injury severity for motorcyclists has been greatly debated. There is growing concern about the risk associated with motorcycles colliding with cable barriers, although to date no definitive evidence has shown that cable barriers are indeed more harmful to motorcyclists than other barrier types. This study analyzed 951 motorcycle–barrier crashes involving 1,047 riders from 2003 to 2008 in North Carolina, Texas, and New Jersey to determine the effect of barrier type on injury severity in crashes. Barrier types were determined by using photographs of the reported crash site. There were 546 W-beam guardrail collisions, 358 concrete barrier collisions, and 47 cable barrier collisions observed. Of the people involved in W-beam collisions with known injury severity, 40.1% were fatally or severely injured. Likewise, 40.3% of people involved in cable barrier collisions with known injury severity were fatally or severely injured. The odds of severe injury in W-beam crashes to concrete barrier crashes were 1.164 (95% confidence interval: 0.889 to 1.524) for all riders involved in the barrier crashes analyzed, which was not significant at the 0.05 level. However, if the rider was helmeted, the odds of severe injury in a W-beam guardrail collision were 1.419 (95% confidence interval: 1.024 to 1.966) times as great as the odds of severe injury in concrete barrier collisions, a factor found to be significant at the 0.05 level. For both helmeted and unhelmeted riders, there was no significant difference in the odds of severe injury between the cable barrier collisions and the W-beam guardrail collisions. However, a smaller number of cable barrier collisions than W-beam guardrail collisions were included in the analysis.
Assessing Performance of Bioretention Boxes in Hot and Semiarid Regions
Authors: Li Ming-Han , Sung Chan Yong , Kim Myung Hee , Chu Kung-Hui
Published: February 2012

This paper presents the performance results of bioretention pilot experiments conducted in Bryan, Texas, a hot and semiarid area. Five steel boxes were constructed. Each of four boxes was filled with an underdrain pipe, gravel, pea gravel, and soil–compost media and planted with a specific type of vegetation, including shrubs, grass species specified for highways in Texas, native grasses, and Bermuda grass (Cynodon dactylon). The fifth box, the control, had no vegetation planting but contained the other materials. Performance testing was conducted 14 months after construction. Synthetic runoff that mimicked highway storm water runoff characteristics was placed into the pilot boxes, and the concentrations of various pollutants in influent and effluent samples were measured. The results suggested that the pilot boxes effectively removed zinc, lead, total suspended solids, and ammonia–nitrogen, but exported copper, nitrate–nitrogen (NO3-N), total nitrogen (TN), and total phosphorus. The leaching out of the boxes by pollutants could be attributed to the use of compost incorporated in the soil–compost media. Vegetation plays an important role in NO3-N and TN removals through root uptake and denitrification processes in the root zone. This paper, based on the results of the study, discusses implications for designing bioretention facilities in a hot, semiarid region.
Public Perception and Sustainable Management Strategies for Roadside Vegetation
Authors: Lucey Anne , Barton Susan
Published: February 2012

Sustainable management strategies for roadside vegetation limit the amount of nonnative turf grass and include masses of native shrubs and trees and meadows of native, warm season grasses, flowering perennials, or both. Sustainably managed roadsides can contribute to a matrix of economically conservative, environmentally responsible, and aesthetically pleasing landscapes. Implementation of sustainable strategies may result in cost savings, better water quality and hydraulic conductivity, improved safety measures, increased biodiversity, benefits to the socioeconomic health of the state, and adherence to state and federal policy. Sustainable strategies provide optimal cost savings and enhancement of environmental stewardship only when implemented consistently. Aesthetically, sustainable landscapes often represent a departure from the traditional expectation of how a roadside landscape should appear. Lacking an awareness of the inherent values present in sustainably managed roadsides, the public is often hesitant to accept this atypical and often less-manicured aesthetic; the public reaction causes many departments of transportation (DOTs) to revert to traditional management regimes. Many state DOTs maintain active ties to the public and political communities of their state and acquiesce to the wishes of these communities when appropriate. Because they are often called on to defend their design, management, and operating procedures, DOTs have a new role in raising awareness, assessing perception, and informing the public about the benefits associated with management strategies for sustainable roadside vegetation. This paper examines the evolution of the roadside landscape and various approaches to vegetation management from the birth of the road network to today's strategies, which include benchmarks for sustainability.
Context-Sensitive Solutions versus Practical Solutions
Authors: Stamatiadis Nikiforos , Hartman Don
Published: February 2012

In recent years, the concept of the context-sensitive solution (CSSs) has been promoted by both AASHTO and FHWA as a best practice for project development. A CSS provides a systematic and comprehensive approach to project development from inception and planning through operations and maintenance. Recently, the economic constraints facing several state departments of transportation have created a new emphasis on financial issues as they relate to project development. Practical design and practical solutions are a process emphasizing design solutions that aim to achieve the maximum rate of return for the individual project and to maximize system returns. As a result, the concepts of practical design and practical solutions have seemingly clashed with CSS. In contrast, these concepts address and emphasize the systemwide optimization that was not addressed by CSS. Moreover, they improve CSS applications and principles by further refining them, and potentially they could add the need to consider systemwide improvements. The main conclusion from the work presented here is that a systematic, principle-driven, benefit-justified project development process is necessary to deliver the appropriate project. This paper presents the concepts and issues for each and compares their approaches, aiming to initiate a dialogue for understanding these approaches and improving the project development process so that it is more comprehensively performance oriented.
Hydrographs and Estimates of Scour Depth Excess for Pier Scour Prediction
Authors: Ting Francis C. K. , Larsen Ryan J. , Jones Allen L.
Published: February 2012

A practical procedure for using the Scour Rate in Cohesive Soils (SRICOS) method to predict bridge pier scour depth in ungauged streams is presented. The procedure is illustrated by the Interstate 90 westbound bridge over Split Rock Creek in South Dakota. Instead of generating a continuous hydrograph for the design service life of a bridge, the simplified approach considered a series of maximum annual floods. The parameters of peak flow distribution were calculated with estimates of peak flow magnitude obtained from regional regression equations. Flood duration was estimated with a rainfall atlas and a Soil Conservation Service runoff curve number based on a design storm. A set of equally probable future hydrographs was generated and used with the SRICOS method to compute the final scour depth. The predicted final scour depth followed the normal distribution. The risk values associated with different design scour depths were calculated with the mean and standard deviation of the normal distribution. The scour predictions were consistent with a bridge founded on highly erosion-resistant cohesive soils. The cumulative effect of scour from the small floods in a long sequence of floods could be represented by an equivalent time; the scour depth produced by the whole sequence could be modeled by using only the large floods if the equivalent time were small compared with the combined duration of the large floods.
Estimating Joint Flow Probabilities at Stream Confluences by Using Copulas
Authors: Kilgore Roger T. , Thompson David B.
Published: February 2012

Highway drainage structures are often located near the confluence of two streams, where the structures may be subjected to inundation by high flows from either stream. These structures must be designed to meet specified performance objectives for floods. Although many tools estimate the probability of flooding on a single stream, there is little guidance for quantifying the probability of flooding on two streams simultaneously, which is a problem of estimating the joint probability of coincident flows. The objective of the research summarized in this paper was to develop practical procedures for estimating joint probabilities of design coincident flows at stream confluences and guidelines for applying these procedures. The scope was limited to riverine areas and did not include coastal areas. Two practical strategies emerged from the analyses: (a) a strategy for determining a set of combinations of exceedance probabilities associated with the desired joint probability for design based on copulas and (b) a series of conditional probability matrices for use in the total probability method. Only the copula strategy is addressed in this paper. The use of a series of design tables makes the procedure straightforward for the designer to apply without the need for a background in statistics. An example application of the method that uses a pair of confluent streams in Washington State is provided. The application illustrates the steps needed for a designer to implement the method. The procedure advances the state of the art by providing a tool applicable to confluent watersheds in the coterminous United States.
Hydrologic Uncertainty in Prediction of Bridge Scour
Authors: Clopper P. E. , Lagasse P. F.
Published: February 2012

Load and resistance factor design (LRFD) incorporates state-of-the-art analysis and design methodologies with load and resistance factors that are based on the known variability of applied loads and material properties. These load and resistance factors are calibrated from actual bridge statistics to ensure a uniform level of reliability. LRFD allows a bridge designer to focus on a design objective or limit state; doing so can lead to a similar probability of failure in each component of the bridge. Bridges designed with the LRFD specifications should have relatively uniform reliability levels; such uniformity should ensure superior serviceability and long-term maintainability. Bridge hydraulics engineers should have the option of and ability to perform scour calculations that incorporate similar probabilistic methods. With this objective in mind, NCHRP Project 24–34 was initiated in April 2010 to develop a risk–reliability-based methodology that was based on risk and reliability and that could be used in calculating bridge pier, abutment, and contraction scour at waterway crossings so that scour estimates could be linked to a probability. The developed probabilistic procedures will be consistent with LRFD approaches used by structural and geotechnical engineers. This paper discusses sources of uncertainty in hydrologic estimates as those sources relate to bridge scour computations and summarizes a conceptual approach to the problem.
Removal, by Vegetated Biofilter, of Medium and Low Concentrations of Pollutants from Simulated Highway Runoff
Authors: Mitchell Gayle F. , Riefler R. Guy , Russ Andrew
Published: February 2012

The removal of pollutants by a prototype of a vegetated biofilter was investigated at medium and low concentrations. The biofilter was 4 ft (1.2 m) wide by 14 ft (4.3 m) long and was tilted at slopes of 8:1, 4:1, and 2:1. Artificial runoff, formulated with metals, native soil, and oil at medium concentration, was delivered at a rate equivalent to a simulated 2-year storm event (medium flow) at each slope; an additional experiment using a 10-year storm event (high flow) was conducted at the 2:1 slope. The flow rates at the low concentration represented 10-year storm events. During each simulated storm event, samples were obtained from the inlet, surface runoff, and underdrain and analyzed for total and dissolved metals, total suspended solids (TSS), and oil and grease. Before and after all tests, specimens were extracted from the bed and analyzed for metal content in soil, roots, and grass. Results indicated that all constituents (seven total metals and TSS) were removed at levels above 75% (event mean concentration) for medium-concentration influent. Metals above background levels were found primarily in the first half [7 ft (2.1 m)] of the bed. Oil removal was also achieved. Removals at low concentration were lower and erratic, and residual metal concentrations in the bed were near background levels. Soil particles in the influent flow, tagged with lanthanum, were neither resuspended nor measured at any significant concentration in the outlet surface flow.
Strategies to Address Utility Challenges in Project Development
Authors: Quiroga Cesar , Kraus Edgar , Overman John
Published: February 2012

Streamlined project delivery is one of the main goals of transportation agencies nationwide to achieve a more efficient and more effective transportation system. Many factors can cause delays while transportation projects are being developed and constructed. A critical factor contributing to inefficiencies is the lack of adequate information about utility facilities that may be affected by a transportation project. This lack results in problems such as unplanned environmental corrective actions and unanticipated utility relocation activities during construction. These unplanned activities cause frequent delays during construction, can increase the impact of construction on motorists and society, and may exacerbate the cost of the project. This paper summarizes the results of research conducted to evaluate the feasibility of (a) obtaining more-reliable existing utility data during preliminary design and coordinating this activity with the environmental process and (b) increasing the level of definition of components during preliminary design without affecting environmental requirements so as to support the earlier application of utility processes. The analysis resulted in 10 optimization strategies that addressed a variety of environmental and utility issues. The researchers also developed a highly detailed business process diagram that integrated environmental and utility functions, with a specific emphasis on the preliminary design phase. To facilitate access to model information, the researchers developed a web-based tool called TxDOT Business Process Explorer, which can be accessed remotely or at a local or networked computer drive.
Evaluation of TIMIT Sentence List Equivalency with Adult Cochlear Implant Recipients
Authors: King Sarah E. , Firszt Jill B. , Reeder Ruth M. , Holden Laura K. , Strube Michael
Published: February 2012

Background:Current measures used to determine sentence recognition abilities in cochlear implant recipients often include tests with one talker and one rate of speech. Performance with these measures may not accurately represent the speech recognition abilities of the listeners.
Evaluation of cochlear implant performance should include measures that reflect realistic listening conditions. For example, the use of multiple talkers who vary in gender, rate of speech, and regional dialects represent varied communication interactions that people encounter daily. The TIMIT
sentences, which use multiple talkers and incorporate these variations, provide additional test material for evaluating speech recognition. Dorman and colleagues created 34 lists of TIMIT sentences that were normalized for equal intelligibility using simulations of cochlear implant processing
with normal-hearing listeners. Adults with sensorineural hearing loss who listen with cochlear implants represent a different population. Further study is needed to determine if these lists are equivalent for adult cochlear implant recipients and, if not, to identify a subset of lists that
may be used with this population.Purpose:To evaluate the speech recognition equivalence of 34 TIMIT sentence lists with adult cochlear implant recipients.Research Design:A prospective study comparing test-retest results within the same group of listeners.Study Sample:Twenty-two
adult cochlear implant recipients who met the inclusion criteria of at least 3 mo device use and a monosyllabic word score of 30% or greater participated in the study.Data Collection and Analysis:Participants were administered 34 TIMIT sentence lists (20 sentences per list) at each
of two test sessions several months apart. List order was randomized and results scored as percent of words correct. Test-retest correlations and 95% confidence intervals for the means were used to identify equivalent lists with high test-retest reliability.Results:Mean list scores
across participants ranged from 66 to 81% with an overall mean of 73%. Twenty-nine lists had high test-retest reliability. Using the overall mean as a benchmark, the 95% confidence intervals indicated that 25 of the remaining 29 lists were equivalent (e.g., the benchmark of 73% fell within
the 95% confidence interval for both test and retest).Conclusions:Twenty-five of the TIMIT lists evaluated are equivalent when used with adult cochlear implant recipients who have open-set word recognition abilities. These lists may prove valuable for monitoring progress, comparing
listening conditions or treatments, and developing aural rehabilitation plans for cochlear implant recipients.
Expansion du marché mondial du gaz naturel liquéfié et stratégies des acteurs. Étude comparative des stratégies algérienne, qatarie et russe
Authors: Senouci Benabbou
Published: February 2012

Résumé Depuis les années soixante du vingtième siècle, l’industrie gazière a affirmé son rôle majeur comme source énergétique à l’échelle mondiale. Ce travail est une étude comparative entre trois pays exportateurs de Gaz Naturel Liquéfié (GNL) : l’Algérie, le Qatar et la Russie. L’essor du marché du gaz naturel a conduit ces trois pays à investir fortement dans ce secteur (à des degrés différents), afin d’accroître leurs productions. Au-delà du discours de l’OPEP sur le gaz, les faits montrent qu’entre les trois pays il y a plus de concurrence et de compétitivité que de coopération pour le devenir de cette OPEP du gaz, l’Algérie jette la pierre au Qatar et la Russie en leur qualité de plus grands exportateurs de gaz naturel au monde ; les stratégies des trois pays ne convergent pas pour le moment. Codes JEL : L12, O57, Q41
The use of konjac glucomannan hydrolysates to recover healthy microbiota in infected vaginas treated with an antifungal agent
Authors: Tester R. , Al-Ghazzewi F. , Shen N. , Chen Z. , Chen F. , Yang J. , Zhang D. , Tang M.
Published: February 2012

The aim of this study was to evaluate how konjac glucomannan hydrolysates (GMH) could support the healthy
re-colonisation of vaginal microflora post infections. A total of 26 female patients (12 controls and 14 treatments)
aged 18 to 25 suffering from vaginal infection were recruited for this study. Patients were assigned randomly into
two groups to receive a standard antifungal treatment or a standard antifungal treatment plus pessary capsules
containing 200 mg GMH (twice a week for thirty days). Patients were assessed on day zero, sixteen and thirty of the
trial. Several parameters were determined including yeast and bacterial counts, the KOH test, pH, Gram staining and
wet mount microscopic observations. The results showed that the counts of Candida were diminished completely
with antifungal treatment for both groups. However, the total bacterial counts increased with time in the GMH
pessary group unlike the control. The normalised average KOH scores were reduced sharply with time in both groups
although in the control group scores started to increase after sixteen days. The normalised average white blood cell
scores also decreased with time for both groups. Epithelial cell scores decreased only for the GMH pessary group
while clue cells and yeast-like fungi decreased with time for both control and GMH pessary groups. These results
indicate the improvement of vaginal health recovery (post antifungal treatment for Candida infection) and especially
the presence of healthy microflora due to the introduction of GMH in the vagina. The data indicate that it would
be worth examining further the health benefits of GMH in a vaginal health format with a view to employing the
material as a prophylactic or therapeutic agent. It provides an alternative approach to reducing vaginal infections
and promoting consumer health.
Science et rhétorique : la double articulation rhétorique du discours scientifique
Authors: Martin Jacky
Published: February 2012

À partir d’une comparaison entre les notions traditionnelles de rhétorique et de science, une nouvelle définition du discours scientifique est proposée fondée sur un double principe de structuration : la spécification du lexique et de la morpho-syntaxe et l’inscription d’un macrotexte paradigmatique orienté par des stratégies rhétoriques.
Vague quantification in the scientific journal article
Authors: Banks David
Published: February 2012

Bien que l’écriture scientifique soit en général considérée précise, elle contient un nombre significatif d’exemples de quantification imprécise. L’étude d’un petit corpus de six articles de recherche scientifique démontre que les expressions constituées uniquement de mots sont distribuées différemment par rapport aux expressions comprenant des chiffres. Dans certains cas, l’imprécision est compensée à l’intérieur même du texte. L’usage de la quantification imprécise est lié au phénomène de hedging. Il est possible que ces traits opèrent sur un gradient triangulaire des dispositifs de hedging.
Nuclear to Cytoplasmic Translocation of Heterogeneous Nuclear Ribonucleoprotein U Enhances TLR-Induced Proinflammatory Cytokine Production by Stabilizing mRNAs in Macrophages
Authors: Zhao Wei , Wang Lijuan , Zhang Meng , Wang Peng , Qi Jianni , Zhang Lei , Gao Chengjiang
Published: February 2012

TLR signaling is associated with the transcription of various proinflammatory cytokines, including TNF-α, IL-6, and IL-1β. After transcription, the mRNA of these proinflammatory cytokines needs to be tightly controlled at the posttranscriptional level to achieve an optimal expression. However, the precise mechanism of posttranscriptional regulation is not fully understood. In the current study, we found the expression of heterogeneous nuclear ribonucleoprotein U (hnRNP U), also termed scaffold attachment factor A, was greatly induced by TLR stimulation in macrophages. Knockdown of hnRNP U expression greatly attenuated TLR-induced expression of TNF-α, IL-6, and IL-1β, but not IL-12, whereas hnRNP U overexpression greatly increased TLR-induced expression of TNF-α, IL-6, and IL-1β. Furthermore, hnRNP U knockdown accelerated the turnover and decreased the t1/2 of TNF-α, IL-6, and IL-1β mRNA. RNA immunoprecipitation demonstrated that hnRNP U bound to the mRNA of these proinflammatory cytokines through the RGG motif. Importantly, we showed that TLR stimulation provided a stimulus for hnRNP U nuclear to cytoplasmic translocation. Therefore, we propose that hnRNP U induced by TLR signaling binds to the mRNA of a subset of proinflammatory cytokines and positively regulates the expression of these cytokines by stabilizing mRNA.
Neutrophil Extracellular Traps That Are Not Degraded in Systemic Lupus Erythematosus Activate Complement Exacerbating the Disease
Authors: Leffler Jonatan , Martin Myriam , Gullstrand Birgitta , Tydén Helena , Lood Christian , Truedsson Lennart , Bengtsson Anders A. , Blom Anna M.
Published: February 2012

Ongoing inflammation including activation of the complement system is a hallmark of systemic lupus erythematosus (SLE). Antimicrobial neutrophil extracellular traps (NETs) are composed of secreted chromatin that may act as a source of autoantigens typical for SLE. In this study, we investigated how complement interacts with NETs and how NET degradation is affected by complement in SLE patients. We found that sera from a subset of patients with active SLE had a reduced ability to degrade in vitro-generated NETs, which was mostly restored when these patients were in remission. Patients that failed to degrade NETs had a more active disease and they also displayed lower levels of complement proteins C4 and C3 in blood. We discovered that NETs activated complement in vitro and that deposited C1q inhibited NET degradation including a direct inhibition of DNase-I by C1q. Complement deposition on NETs may facilitate autoantibody production, and indeed, Abs against NETs and NET epitopes were more pronounced in patients with impaired ability to degrade NETs. NET-bound autoantibodies inhibited degradation but also further increased C1q deposition, potentially exacerbating the disease. Thus, NETs are a potent complement activator, and this interaction may play an important role in SLE. Targeting complement with inhibitors or by removing complement activators such as NETs could be beneficial for patients with SLE.
Galectin-1 Triggers an Immunoregulatory Signature in Th Cells Functionally Defined by IL-10 Expression
Authors: Cedeno-Laurent Filiberto , Opperman Matthew , Barthel Steven R. , Kuchroo Vijay K. , Dimitroff Charles J.
Published: February 2012

Galectin-1 (Gal-1), a β-galactoside–binding protein, can alter fate and effector function of Th cells; however, little is known about how Gal-1 induces Th cell differentiation. In this article, we show that both uncommitted and polarized Th cells bound by Gal-1 expressed an immunoregulatory signature defined by IL-10. IL-10 synthesis was stimulated by direct Gal-1 engagement to cell surface glycoproteins, principally CD45, on activated Th cells and enhanced by IL-21 expression through the c-Maf/aryl hydrocarbon receptor pathway, independent of APCs. Gal-1–induced IL-10+ T cells efficiently suppressed T cell proliferation and T cell-mediated inflammation and promoted the establishment of cancer immune-privileged sites. Collectively, these findings show how Gal-1 functions as a major glycome determinant regulating Th cell development, inflammation, and tumor immunity.
Acute Concomitant Anterior Cruciate Ligament and Patellar Tendon Tears in a Non-dislocated Knee
Authors: Wissman Robert D. , Vonfischer Nathaniel , Kempf Kari
Published: February 2012

Anterior cruciate ligament (ACL) tears are common and may occur in isolation or with other internal derangements of the joint. Tears of the patellar tendon (PT) occur less frequently and are rarely associated with intra-articular pathology. Acute combined tears of both the ACL and PT are known complications of high-energy traumatic knee dislocations. We present a case of an acute concomitant ACL and PT tears in a low-energy non-dislocated knee. To our knowledge, this injury has only been described in a limited number of case reports in the orthopedic literature. We present the imaging findings of this combined injury and discuss the importance of magnetic resonance (MR) in diagnosis.
An Unusual Case of Extraosseous Accumulation of Bone Scan Tracer in a Renal Calculus - Demonstration by SPECT-CT
Authors: Joshi Prathamesh Vijay , Lele Vikram , Gandhi Rozil
Published: February 2012

Extraosseous localization of radioisotope, used in bone scan, in a variety of physiological and pathological conditions is a well-known phenomenon. The causes of extraosseous accumulation of bone-seeking radiotracers should be kept in mind when bone-imaging studies are reviewed to avoid incorrect interpretations. We report an extremely rare occurrence of extraosseous accumulation of bone scintigraphy tracer in a renal calculus, in a patient with adenocarcinoma of prostate, that was demonstrated by Single Photon Emission Computed Tomography and Computed Tomography (SPECT-CT) fusion imaging.
Fibrochondrogenesis, an Antenatal and Postnatal Correlation
Authors: Kundaragi Nischal G. , Taori Kishor , Jathar Chetan , Disawal Amit
Published: February 2012

Fibrochondrogenesis is a rare, neonatally lethal osteochondrodysplasia, with autosomal recessive inheritance. It differs from other lethal dwarfisms in that it leads to broad, long-bone metaphyses (dumb-bell shaped) and pear-shaped vertebral bodies. We report a case of fibrochondrogenesis with severe pear-shaped platyspondyly, suspected antenatally, and give a comprehensive pictorial review of the antenatal ultrasound and postnatal radiographic findings. Only few cases of fibrochondrogenesis are diagnosed before the termination of pregnancy.
Krukenberg Tumor: A Rare Cause of Ovarian Torsion
Authors: Sandhu Sameer , Arafat Omar , Patel Harshad , Lall Chandana
Published: February 2012

Ovarian torsion is the fifth most common gynecological surgical emergency. Ovarian torsion is usually associated with a cyst or a tumor, which is typically benign. The most common is mature cystic teratoma. We report the case of a 43-year-old woman who came to the Emergency Department with rare acute presentation of bilateral Krukenberg tumors, due to unilateral ovarian torsion. In this case report, we highlight the specific computed tomography (CT) features of ovarian torsion and demonstrate the unique radiological findings on CT imaging. Metastasis to the ovary is not rare and 5 to 10% of all ovarian malignancies are metastatic. The stomach is the common primary site in most Krukenberg tumors (70%); an acute presentation of metastatic Krukenberg tumors with ovarian torsion is rare and not previously reported in radiology literature.