bluuebunny/crossref_metadata_2025 huggingface dataset:
Speed Difference and Its Impact on Traffic Safety of One Freeway in China
Authors: Chen Yongsheng , Sun Xiaoduan , Zhong Liande , Zhang Guowei
Published: February 2008

Although speed differential has long been recognized as a contributing factor to highway crashes, its relationship with crash rate has not been quantitatively established. An analysis of the crash data collected from the Jingjintang Expressway, one of the first freeways to be built in China, reveals a clear association between speed gap and crash rate. A difference in average operating speed between large and small vehicles of 10 to 15 km/h, reflecting a specific traffic composition, is associated with an unusually high crash rate. The speed differential problem is worse in developing countries because of the huge demand for freight transportation. Overloading is a common problem on highways. Heavily loaded trucks cannot reach the minimum freeway speed and so cause other vehicles to change lanes frequently; the situation consequently increases crash risks. Analysis results strongly suggest that managing the speed gap between large and small vehicles would be the most crucial step in combating the highway crash problem.
Rail Transit and Residential Land Use in Developing Countries
Authors: Chalermpong Saksith
Published: February 2008

The effects of public transit improvements on residential land use in general, and on residential property prices in particular, have not been well investigated in developing countries. Such an understanding is necessary for the formulation of value capture policies, which can be instrumental in the financing of transit infrastructure. In this paper past studies on the effect of transit improvements on property prices in developing countries are reviewed, and the hedonic models are developed to examine this relationship in Bangkok, Thailand. Spatial regression models are estimated with data on multifamily residential properties near the Bangkok transit system's stations. Estimation results show that the premium of transit accessibility is approximately $10 for every meter closer to a station, and the price elasticity with respect to the distance to the nearest station is roughly −0.09. These findings are consistent with the range found in past studies from other developing countries. The substantial premium of transit accessibility implies that there is a great potential for the use of value capture policies to raise additional funds for investments in Bangkok's transit system.
Household Income, Travel Behavior, Location, and Accessibility
Authors: Zegras P. Christopher , Srinivasan Sumeeta
Published: February 2008

This paper analyzes the differences in travel behavior and location characteristics across different income groups in two cities in different parts of the world: Chile and China. Vehicle ownership rates, mode choices, trip rates and purposes, and travel times and distances are compared according to high-, middle-, and low-income terciles in Chengdu, China, and Santiago, Chile, with the use of recent household travel surveys. Household location characteristics are also compared, and different measures of accessibility are presented. Results suggest commonalities and differences and build a foundation on which future analytical models can be developed and more rigorous and comparable accessibility measures might be derived.
Characteristics of Traffic Crashes on Freeways in China
Authors: Sun Xiaoduan , Chen Yongsheng , He Yulong , Liu Xiaoming , Hu Jiangbi
Published: February 2008

As China feverishly builds one of the largest freeway systems in the world to meet its ever-increasing demand for highway transportation–stimulated by the unprecedented economic boom–traffic safety has become a serious concern. The problem of more than 100,000 annual traffic fatalities is threatening the country's sustainable economic development. The significant differences in road user behavior, level of motorization, traffic enforcement practice, roadside design criteria, and economic development stage make the characteristics of traffic crashes in China somewhat different from those in developed countries. To reduce traffic crashes it is important to investigate what, when, how, and why those crashes occurred. This paper introduces a highway safety project conducted on Jingjintang Expressway, one of the first freeways built in China. Results of the study show that, among other factors, the speed differential between cars and large vehicles is a main cause of high crash fatalities, particularly for rear-end collisions. The lack of real-time enforcement, problematic driver behavior, and substandard roadside design, as well as overloaded trucks all contribute heavily to traffic crashes on China's freeways.
Vehicle Activity Patterns and Emissions in Pune, India
Authors: Barth Matthew , Davis Nicole , Lents James , Nikkila Nick
Published: February 2008

India continues to experience substantial economic growth, with increased travel demand for both passengers and goods. As a result, roadway congestion is increasing in many cities and putting significant pressure on India's transportation infrastructure. One key concern is air pollution related to the increased transportation activity. To understand the transportation impacts on air quality, it is necessary to develop and apply appropriate modeling tools to the area of concern. Recently, a new on-road mobile source emissions model designed for use in developing countries has been developed: the international vehicle emissions (IVE) model. The IVE model was developed jointly by researchers at the International Sustainable Systems Research Center and the University of California at Riverside. This paper describes a research program that applied the IVE modeling approach to the city of Pune, India. As part of the approach, an extensive vehicle activity–fleet composition study took place in Pune; it consisted of videotaping and measuring traffic patterns, tracking representative vehicles with Global Positioning System data loggers, monitoring start–stop patterns in instrumented vehicles, and conducting surveys in the field. In this paper, the methodology and results of the study are described in detail, followed by mobile-source emissions predictions based on the calibrated IVE model. This overall effort was designed to support estimates of the air pollution impacts of on-road transportation in Pune that can now be used extensively in the development of air quality and transportation management plans for the region. It is also hoped that the collected data can be extrapolated to other Indian cities to support further environmental improvement efforts.
Modeling Bus Lane Priorities in a Motorcycle Environment Using SATURN
Authors: Tranhuu Minh , Montgomery Frank , Timms Paul
Published: February 2008

Bus lanes and median bus ways such as those in Curitiba, Brazil, and Bogotá, Colombia, are attracting a great deal of attention worldwide. For many Asian developing cities, there is an interest in how successfully bus lanes and bus rapid transit will function, given that traffic conditions in such cities typically are different from those found in Latin America. This paper addresses this issue for Asian cities whose traffic is dominated by motorcycles, concentrating particularly on Hanoi, Vietnam. With the use of a SATURN mesoscopic simulation model for Hanoi (with 322 junctions and 1,108 links), different bus lane–bus way designs are compared in regard to their effects on travel time savings. Results show that the level of motorcycle violations has an important impact on the success of bus lane schemes and that there is no significant speed improvement on bus lanes if enforcement is weak. Bus ways can achieve much higher bus speeds than can bus lanes, but general traffic speeds are likely to reduce them significantly if there is no mode switching from private modes to buses. In such circumstances the potential extra delay due to a poorly designed bus way is greater than that due to a poorly designed bus lane. The route-switching flexibility of motorcycles also has considerable effects on the performance of bus lanes and bus ways.
Early Contractor Involvement and Target Pricing in U.S. and UK Highways
Authors: Molenaar Keith R. , Triplett James E. , Porter Jerry C. , DeWitt Steven D. , Yakowenko Gerald
Published: February 2008

A U.S. panel of federal, state, and private-sector professionals traveled to Canada and Europe in May 2004 to conduct a scan of construction management practices for effective project delivery, contract compliance, and quality assurance. The purpose of this research was to review and document international policies, practices, and technologies for potential application in the United States. The research team observed construction management methods that promote alignment of team goals, integrated use of risk analysis techniques, strategic use of alternative delivery methods, procurement systems that set a framework for success, contract payment methods that support alignment and trust, a delegation of traditional highway agency functions to promote efficiency, a philosophy of network management, and a greater partnership between public and private agencies. One of the significant discoveries dealt with the use of target pricing by the Highways Agency in England on its early contractor involvement projects. As a result of this scan finding, a target pricing proposal was submitted to the South Carolina Department of Transportation (DOT). Additionally, it was discovered after the scan that a form of target pricing has been employed in the state of Washington. Target pricing concepts from the Highways Agency in England, South Carolina DOT, and Washington State DOT are summarized. The aim of the target pricing technique is to align team goals by establishing the contractor's role early in the project development process and then sharing risks rationally and equitably through to project completion.
Framework Model for Determining Incentive and Disincentive Amounts
Authors: Sillars David N. , Riedl John
Published: February 2008

To create schedule focus during construction of public highways, monetary incentives and disincentives (I/Ds) are often offered to highway contractors. An appropriate I/D amount meets two conditions. First, the I/D amount needs to be greater than or equal to the contractor's cost of acceleration (CA) plus appropriate profit, the lower bound. Second, the I/D amount must be less than or equal to the road user cost (RUC) of the construction delay, the upper bound. RUCs are commonly calculated by most departments of transportation. Less understood is calculation of the lower bound; no practical methodology has emerged in previous studies. To determine a lower bound, a component analysis of the contractor's costs for the focus portion of work is necessary. The effect of acceleration may then be summed to establish the raw CA and then increased with appropriate incentive profit and compared against RUCs. Contractor pricing details are hidden and vary widely, so a methodology for estimating such details would be helpful. A method is proposed for establishing the I/D lower bound that is practical, repeatable, and auditable, and that may be customized for each project. Further, a framework is established for future refinement of factors affecting contractor pricing.
Comparisons of Contractor and State Transportation Agency Quality Assurance Test Results on Mat Density of Hot-Mix Asphalt Concrete
Authors: Turochy Rod E. , Parker Frazier
Published: February 2008

A typical component of highway construction quality assurance programs is the process by which highway construction elements are sampled and tested to ensure compliance with specifications and other project requirements. The results of contractor-performed tests on in-place properties of hot-mix asphalt are increasingly used in the acceptance decision in many states. Results of tests performed by contractors and state departments of transportation (DOTs) in North Carolina, Florida, and Kansas consistently indicate that differences between contractors and state DOT test results for hot-mix asphalt concrete mat density are statistically significant. Furthermore, these comparisons consistently indicate less variable and more favorable contractor test results, relative to specification limits, that give more favorable acceptance outcomes. Details of quality assurance processes (sampling and testing frequencies, test methods, verification procedures, and acceptance procedures) appear to have little if any effect on these comparisons. These findings provide information for state DOTs to consider in structuring their quality assurance programs, specifically the role of contractor-performed tests in acceptance decisions.
Value of Pavement Smoothness
Authors: McGhee Kevin K. , Gillespie James S.
Published: February 2008

Smoothness, the absence of bumps and dips in the riding surface of a pavement, improves the quality of the ride and is believed to prolong the life of the pavement. Research addressed the effect of Virginia's special provision for smoothness on contract prices for hot-mix asphalt. The research also examined the financial value of the resulting product (presumably smoother pavements). The analysis included maintenance cost savings for the owner–agency, as well as any reduction in delay and operating costs for the motoring public. A detailed statistical analysis found no statistically definitive effect on bid price as a result of the use of a special provision for rideability. A similar analysis on a more focused data set, however, did document a lifetime reduction in the international roughness index of almost 9 in./mi. This reduction in roughness (increase in smoothness) implies an increase in pavement service life, which translates into reduced annual maintenance costs. The lifetime decrease in roughness can lead to even more dramatic user cost savings. A case study demonstrated a fuel cost savings (for trucks alone) of $190,000 over a 10-year period for each lane mile of highway resurfaced under the special provision.
Launching of the San Cristobal Bridge
Authors: Nader Marwan , Manzanarez Rafael , Lopez-Jara Jack , De La Mora Carlos
Published: February 2008

The San Cristobal Bridge in Chiapas, Mexico, is a three-span (71.5, 180, and 71.5 m) curved steel composite and orthotropic box girder erected by incremental launching. Lessons learned from the collapse during launching of the San Cristobal Bridge as well as the redesign and relaunching of the new bridge are discussed. After the collapse of the San Cristobal Bridge, T. Y. Lin International was hired by the new contractor, Ingenieros Civiles Asociados, to investigate the cause of the collapse of the original bridge, check the redesign of the bridge, and perform the erection engineering of the bridge. From the site investigation, it was concluded that the collapse of the structure was caused primarily by the failure of the shear studs and the consequent loss of composite action of the girder cross section over Pier 2. To ensure the safe erection of the structure, the redesign of the new bridge included the following changes: addition of shear studs, increase of deck posttensioning during launching, increase of the concrete slab strength, and addition of stiffeners to the bottom flange and webs. To match the predicted and measured deflections during launching, a calibration of the effective deck inertias (consistent with a 12 × tslab and contrary to the AASHTO specifications) was necessary to account for the effects of shear lag and the actual effective slab width.
Roller-Compacted Concrete Shoulder Construction on Interstate Highway in Georgia
Authors: Kim Yeonsoo Stanley
Published: February 2008

In 2004, the Georgia Department of Transportation (GDOT) used roller-compacted concrete (RCC) for Interstate 285 shoulder reconstruction in Atlanta. This instance marks the first usage of RCC pavement in the Interstate highway system in the United States. The construction procedures are described, and the mix design data for the RCC material are presented. The results of a comprehensive field and laboratory investigation of the pertinent material properties are also presented. The 6- and 8-in. (150- and 200-mm) RCC shoulder was constructed with minimal disruption for the traveling public and has performed well to date. The RCC mix was designed for a 4,000-psi (27.6-MPa) compressive strength with 0.5-in. (12.5-mm) maximum size aggregate. More than 98% of the maximum wet density, as specified in the GDOT provision for average in-field density, was achieved in tests at random locations. The average compressive strength in the middle section showed close agreement with the design strength. Reasonably good density and strength values were achieved in the longitudinal joint area and right edge area. The strength from the field-manufactured cylinders did not adequately represent the core strength of RCC, but it was recommended to include the cylinder test in the specification to monitor mixture variability and strength development. A small increase in average density resulted in a larger increase in average compressive strength, but no strong linear relationship was established in individual data. The 8-in. RCC section demonstrated a higher average strength than the 6-in. section, but it also showed a greater propensity for shrinkage cracks.
Laboratory Evaluation of Alternative Dowel Bars for Use in Portland Cement Concrete Pavement Construction
Authors: Porter Max , Pierson Nathan
Published: February 2008

Dowel bars are a useful tool for transferring loads from one highway concrete slab to another across joints. Although dowels are used to increase load transfer capabilities across joints, they introduce problems, including stress concentrations and corrosion. Most dowel bars have circular cross sections. The regions of stress concentration for circular dowels are at the top and bottom of the cross section. However, alternative materials and shapes may perform better. Study results showed that elliptically shaped dowels reduced bearing stresses at the dowel–concrete interface. Much research has been conducted at Iowa State University and nationally to study parameter changes and performance of dowels. Parameters including dowel material, dowel shape, joint width, and dowel spacing have been used to evaluate bearing stress performance. Laboratory testing, field testing, and finite element analysis have all been performed to study these parameters. Six highway dowel types representing a variety of material and shape parameters were studied at Iowa State University. All dowels were found adequate to transfer normal highway loads. The deflections measured for all dowels were well within the recommended maximum deflection to ensure rider comfort. The calculations and evaluation of six dowel types showed that none of the specimens failed (dowel yield or concrete failure) before the American Concrete Institute Committee 325 allowable stress was achieved. All six dowels could transfer loads of at least 5,000 lb without exceeding the allowable stresses. Some of the significant findings from this most recent study of dowel parameters are addressed.
Assessing Potential for Warm-Mix Asphalt Technology Adoption
Authors: Kristjánsdóttir Ólöf , Muench Stephen T. , Michael Larry , Burke Gloria
Published: February 2008

Warm-mix asphalt (WMA) describes a range of technologies that seek to lower emissions and reduce energy consumption by lowering the temperature at which asphalt mixtures are produced and placed. Despite these benefits, reduced mixture viscosity may be the most likely reason for widespread adoption of WMA technologies. Hot-mix asphalt (HMA) producers are unlikely to adopt WMA technologies solely to lower emissions, because current environmental regulations and the relatively clean nature of HMA plants make lower emissions unnecessary and unprofitable except in select air pollution areas. Producers are also unlikely to adopt WMA technologies solely to reduce energy consumption, because energy savings are less than the associated costs except in the most expensive energy markets. Reduced viscosity makes the best business case for widespread WMA technology adoption, because this benefit offers cost and risk reduction: it can (a) alleviate compaction problems associated with cool weather, (b) reduce compaction equipment needs at the job site, and (c) lower the risk of poor compaction when working with stiff mixtures. This conclusion is supported by basic economic calculations, a survey of the Icelandic pavement industry showing strong support for WMA technology use to improve cool weather paving, and two projects in Maryland showing the potential for WMA technology use to lower the risk of poor compaction of high reclaimed asphalt-pavement mixtures.
Forensic Investigation of Debonding in Rich Bottom Pavement
Authors: Willis J. Richard , Timm David H.
Published: February 2008

Rich bottom flexible pavements have become more prevalent as state agencies have begun building perpetual pavements to meet the growing demand for high-performing long-life pavements. The rich bottom uses higher asphalt contents, typically 0.5% above optimum, to achieve greater density and resistance to fatigue. In this way, bottom-up fatigue cracking and consequential full-depth repairs can be eliminated. A rich bottom pavement was included in the 2003 research cycle at the National Center for Asphalt Technology test track to evaluate its effectiveness in controlling fatigue. Although it was expected to perform better than comparable sections, it failed first, in fatigue. An investigation was made to find the cause of the failure and to recommend further action regarding rich bottom pavements. In the course of the study, it was determined that slippage between layers (a construction issue), rather than the increased asphalt content, led to the early failure of the section. Theoretical and measured strain responses, forensic trenching, and laboratory shear strength testing support this conclusion. It was also concluded, as in all pavement construction, that interface bond strength plays a crucial role in pavement performance.
Achieving 4% Air Voids in Real Pavements with Superpave
Authors: Harmelink Donna , Aschenbrener Tim , Shuler Scott
Published: February 2008

The Superpave® mix design method has been used by the Colorado Department of Transportation since 1995. Initially, the number of design gyrations used was as recommended by SHRP research. However, the asphalt contents of these preliminary paving mixtures were lower than what had been historically successful for similar dense graded mixtures under similar conditions. This lower asphalt content began leading to premature moisture damage failures. Therefore, a study was initiated to determine how the pavements constructed according to the original Superpave compaction criteria densified under traffic. An experiment was designed to evaluate the in situ voids in 22 full-scale pavements over a 6-year period. Projects were selected on the basis of variation in traffic, environment, temperature, and elevation. Results of this research indicate that the original number of design gyrations recommended by SHRP for field-mixed–laboratory-compacted materials results in pavements that did not compact sufficiently under traffic, resulting in higher air voids than desired after 3 years service. An adjustment to the original SHRP design gyration levels was done in a subsequent study based on NCHRP research. The result of this revision has been a decrease in voids levels after 3 years of service with a corresponding improvement in performance. Further fine-tuning is needed and will be implemented in the future.
Calibration of Nonnuclear Density Gauge Data for Accurate In-Place Density Prediction
Authors: Rao Chetana , Von Quintus Harold , Schmitt Robert L.
Published: February 2008

Hot-mix asphalt (HMA) density is an important acceptance quality characteristic, which involves in situ tests for quality control and assurance (QC/QA). Highway agencies have conventionally used nuclear density gauges or core samples for mat density. More recently, alternate nondestructive testing methods have been considered to replace current test methods. Nonnuclear density gauges offer rapid testing while eliminating safety risks and costs associated with radioactive license. Although agencies have evaluated them, they are not implemented in acceptance testing so far. Results are presented from a field evaluation of three nonnuclear density gauges—PaveTracker, PQI 300, and PQI 301—conducted on Wisconsin Department of Transportation (WisDOT) paving projects. The main goal was to evaluate the performance and effectiveness of non-nuclear gauges for use in QC/QA activities by WisDOT. The study involved field tests at 16 project sites and included 21 mix designs and a variety of mix design and pavement design parameters, such as aggregate type, nominal maximum aggregate size, layer thickness, design traffic, and base type. Density measurements were recorded at 30 test points at each site with one nuclear gauge and three nonnuclear gauges. Although the mean standard deviation values of the nonnuclear gauge data were less than those of the nuclear gauge measurements, a consistent bias was observed between the two data sets. This bias was adjusted by using a calibration factor to yield density predictions statistically the same as the nuclear gauge measurements. It is recommended that a calibration factor determined from 10 points by using a slope function be implemented for agency use. Further, daily calibration for each mix design is recommended when the project involves multiple paving days.
Treatment of degloving injuries with autogenous full thickness mesh scrotal free grafts
Authors: Dhupa S. , Harris J. E.
Published: February 2008

In this report, we evaluated the effectiveness of scrotal tissue as an autogenous free skin graft to treat cutaneous degloving injuries of the distal limb in dogs. Surgery was performed on two male intact dogs with distal extremity degloving wounds. Dog #1 had a tarsal degloving wound with exposure of the distal tibial and tarsal bones. Dog #2 had a degloving injury over the metacarpals. Wounds were treated with daily wetto- dry bandages in order to develop a healthy bed of granulation tissue at the graft recipient site. Scrotal ablation castration was performed once the recipient site had been prepared. Subcutaneous and adipose tissue were excised from the scrotal graft and mesh slits were created. The graft was applied to the recipient site with monofilament absorbable simple interrupted sutures. Bandaging was performed postoperatively, and bandage changes occurred four, seven, nine and 11 days postoperatively. Follow-up was performed at 30 days. In dog #1, the tarsal degloving injury graft had first intention healing with 100% graft take on day 11. In dog #2, the metacarpal degloving injury graft had 90% graft take on day nine, with second intention healing adjacent to the fifth digit pad. The scrotum is often discarded at the time of scrotal ablation castration. Distal extremity wounds can be successfully treated with free skin grafts. In male dogs, the scrotum is a viable option as a full thickness mesh free graft for distal extremity reconstructive surgery.
Mechanical testing of 3.5 mm locking and non-locking bone plates
Authors: DeTora M. , Kraus K.
Published: February 2008

Locking plate technologies are being developed in order to provide the surgeon with advantages over previous bone plate systems (both locking and non-locking). Locking plate systems possess inherent biological advantages in fracture fixation by preserving the periosteal blood supply, serving as internal fixators. It is important to consider the strength of each orthopaedic implant as an important selection criterion while utilizing the reported advantages of locking plate systems to prevent catastrophic fracture failure. Mechanical testing of orthopaedic implants is a common method used to provide a surgeon with insight on mechanical capabilities, as well as to form a standardized method of plate comparison. The purpose of this study was to demonstrate and to quantify observed differences in the bending strength between the LCP (Limited Contact Plate), LC-DCP, 3.5 mm Broad LC-DCP (Limited Contact Dynamic Compression Plate), and SOP (String of Pearls) orthopaedic bone plates. The study design followed the ASTM standard test method for static bending properties of metallic bone plates, which is designed to measure mechanical properties of bone plates subjected to bending, the most common loading encountered in vivo. Single cycle four point bending was performed on each orthopaedic implant. The area moment of inertia, bending stiffness, bending strength, and bending structural stiffness were calculated for each implant. The results of this study demonstrated significant differences (p<0.001) in bending strength and stiffness between the four orthopaedic implants (3.5 Broad LC-DCP>SOP>LCP=LC-DCP). The 3.5 mm LCP should be expected to provide in vivo strength and stiffness similar to a comparable LC-DCP. The SOP should provide strength and stiffness that is greater than a comparable LC-DCP but less than a 3.5 mm Broad LC-DCP.
Proximal tibial epiphysiodesis to reduce tibial plateau slope in young dogs with cranial cruciate ligament deficient stifle
Authors: Bohorquez Vanelli A. , Modenato M. , Dziezyc J. , Devine Slocum T. , Vezzoni A.
Published: February 2008

The purpose of this study was to evaluate the ability of proximal tibial epiphysiodesis to reduce the tibial plateau slope in young dogs with cranial cruciale ligament (CCL) deficient stifles. Of the 14 treated dogs, eight had a bilateral injury, for a total of 22 joints. After physical and radiographical examination and measurement of tibial plateau slope, all of the dogs underwent surgery. Insertion of the screw was placed in the most proximal part of the tibial plateau, in its medio-lateral centre, aiming to the tibial shaft and using a K wire predriven as a guide; correct position of the screw was confirmed with intraoperative fluoroscopy or radiography. In all of the dogs the tibial slope was decreased at the time of physis fusion and the degree of change depended on the age and the breed of the dog at the time of surgery. The minimum change was 4° and the maximum was 24°. There was a statistically significant difference between tibial slope measured before surgery compared to tibial slope measured at the last follow-up visit after surgery. This study shows that the partial proximal tibial fusion in dogs with ACL injuries was effective in reducing the tibial slope during the residual growing time to such an extent to stabilize the joint, provided that the surgery had been carried out when there was still residual growing potential. The technique appeared to be mini-invasive and malalignment complications could be avoided by correct and precise insertion of the screw.
Factors affecting outcome of extensor tendon lacerations in the distal limb of horses
Authors: Martens A. , Bogaert L. , Wilderjans H. , Mespoulhès-Rivière C.
Published: February 2008

Distal limb lacerations are common injuries in horses, with a better prognosis reported for extensor tendons lacerations compared to flexor tendons lacerations. The objective of the present study was to determine the influence of type and location of injury, modalities of treatment and post surgical complications on the outcome of extensor tendon lacerations. The medical records of 156 horses surgically treated for extensor tendon lacerations over a 10-year period were analysed retrospectively. Information was obtained for 124 horses with a minimum of 18 months follow-up. Statistical analysis was performed on 129 horses (five horses were euthanatized during hospitalization) in order to determine factors affecting outcome. Seventy-four percent of the horses returned to soundness, 17% had moderate gait impairment and 9% remained lame. Approximately 60% of the sports horses returned to an equal or higher level of performance, and 17.5% returned to a lower level. In the multivariate statistical analysis, the only significant factor that favourably influenced outcome was complete suture of the wound. A significant association could not be detected between outcome and absence of a functional extensor tendon, The most important post-surgical complication was extensive scarring of the wound. The present results report outcome of extensor tendon lacerations in a large number of horses and outline the importance of primary wound healing in order to avoid major scarring with potential functional consequences.
Axial pull-out strength of 3.5 cortical and 4.0 cancellous bone screws placed in canine proximal tibias using manual and power tapping
Authors: Soniat M. E. , Elder S. , McLaughlin R. , Demko J. L.
Published: February 2008

An in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18–33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pullout strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8±56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.
Cauda equina syndrome treated by lumbosacral stabilisation in a cat
Authors: Cariou M. P. , Petite A. F. , Rayward R. M. , Störk C. K.
Published: February 2008

In this case report, a case of cauda equina syndrome arising from lumbosacral disease in an eight-year-old Burmese cat is described. The cat had a history of chronic right pelvic limb lameness. Neurological evaluation was consistent with a lesion involving the cauda equina. Radiographic findings were consistent with a diagnosis of lumbosacral disease. Due to perceived dorsoventral lumbosacral instability, dorsal decompression and stabilisation of the lumbosacral junction was performed. An original method of spinal stabilisation for this indication is described. The cat had a successful long-term outcome with complete resolution of its presenting clinical signs.
Traumatic dislocation of the lumbosacral joint in two cats
Authors: Koch D. , Voss K. , Zulauf D.
Published: February 2008

The clinical and radiological features, surgical treatment, and outcome of two cats with traumatically induced dislocation of the lumbosacral joint are described in this report. The dislocation of the lumbosacral joint was concurrent with dorsal luxation of the articular facets in both cases. Open reduction, followed by stabilization with a dorsal suture sling, resulted in a good clinical outcome.
Electrophilic Fluorination with
N
–
F
Reagents
Authors: Baudoux Jérôme , Cahard Dominique
Published: February 2008

The synthesis of selectively fluorinated molecules is an important challenge in organic chemistry. This topic has received considerable attention because of the utility of fluorinated compounds in a wide variety of disciplines. There are three types of fluorination depending on whether the fluorine atom is radical, anionic, or cationic. Fluorine radicals are of little synthetic use because of the difficulties in controlling their reactivity. Fluorine is utilized in nucleophilic as well as electrophilic fluorinations Molecular fluorine is the simplest reagent of this type, however, its safe handling is difficult. Stable, selective reagents are crucial to the development of electrophilic fluorination. N‐F reagents have emerged as generally safer and easier to handle selective sources of electrophilic fluorine. N‐F reagents offer a range of fluorinating powers and some are available commercially. Two classes are known: neutral N‐F reagents and quaternary ammonium N‐F reagents (quaternary salts are usually the more powerful). N‐F reagents popularity arises because they posses a long shelf life, several are commercially available, and they can be handled safely in glassware. The drawback is the preferential use of molecular fluorine for their preparation. This article deals with the preparation and the use of all types of electrophilic fluorinating agents possessing the N‐F moiety.
Ketones of Four or Five Carbons
Authors: O'Donoghue John L.
Published: February 2008

A ketone is an organic compound containing a carbonyl group (CO) attached to two carbon atoms and can be represented by the general formula

image

Several billion pounds of ketones are produced annually for industrial use in the United States. Those with the highest production volumes include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4‐hydroxy‐4‐methyl‐2‐pentanone, isophorone, mesityl oxide, and acetophenone. Common methods used to manufacture ketones include aliphatic hydrocarbon oxidation, alcohol dehydration with subsequent oxidation, dehydrogenation of phenol, alkyl aromatic hydrocarbon oxidation, and condensation reactions.

Ketones are used because of their ease of production, low manufacturing cost, excellent solvent properties, and desirable physical properties such as low viscosity, moderate vapor pressure, low to moderate boiling points, high evaporation rates, and a wide range of miscibility with other liquids. The low‐molecular‐weight aliphatic ketones are miscible with water and organic solvents, whereas the high‐molecular‐weight aliphatic and aromatic ketones are generally immiscible with water. Most ketones are chemically stable. The exceptions are mesityl oxide, which can form peroxides, and methyl isopropenyl ketone, which polymerizes. Most ketones are generally of low flammability.

Ketones are commonly used in industry as solvents, extractants, chemical intermediates, and, to a lesser extent, flavor and fragrance ingredients. Ketones have also been reported in the ambient air, in wastewater treatment plants, and in oil field brine discharges.
Cover Picture: Surface Wrinkles for Smart Adhesion (Adv. Mater. 4/2008)
Authors: Chan E. P. , Smith E. J. , Hayward R. C. , Crosby A. J.
Published: February 2008

A patterned adhesive, based on surface wrinkling through swelling of a laterally confined polymer film, is presented by Alfred J. Crosby and co‐workers on p. 711. The image highlights the interface between the wrinkles (bright cylinders) of the patterned adhesive separating from a glass substrate (circular region). Enhanced control of adhesion is attributed to contact line splitting, which is fundamental to adhesion control in numerous examples in nature, for example, the gecko.
Inside Front Cover: Could Green be Greener? Novel Donor–Acceptor‐Type Electrochromic Polymers: Towards Excellent Neutral Green Materials with Exceptional Transmissive Oxidized States for Completion of RGB Color Space (Adv. Mater. 4/2008)
Authors: Gunbas G. E. , Durmus A. , Toppare L.
Published: February 2008

The design and synthesis of novel donor–acceptor type polymers that are green in the neutral and highly transmissive in the oxidized state were presented. The polymers reveal superior optical contrasts in the visible region, exceptional long‐term stability, and extremely fast switching times. Combined, these materials are paramount candidates for completion of RGB color space towards realization of display devices, report Levent Toppare and co‐workers on p. 691.
Lethal vascular leak syndrome after denileukin diftitox administration to a patient with cutaneous gamma/delta T‐cell lymphoma and occult cirrhosis
Authors: Avarbock Andrew B. , Loren Alison W. , Park Jason Y. , Junkins‐Hopkins Jacqueline M. , Choi John , Litzky Leslie A. , Rook Alain H.
Published: February 2008

Denileukin diftitox (Ontak) is an immunotoxin used in the treatment of cutaneous T‐cell lymphomas. Vascular leak syndrome is a known complication of this therapy, although the syndrome is most often self‐limited. We report the case of a patient with cutaneous gamma/delta (γδ) T‐cell lymphoma and previous undiagnosed liver disease treated with denileukin diftitox. Just 4 days after initiating drug therapy, the patient developed profound vascular leak syndrome characterized by a rapid fall in his previously normal serum albumin to levels below the limit of detection. The patient then quickly deteriorated into rhabdomyolysis and eventual death. To our knowledge, this is the first report of a death directly related to denileukin diftitox therapy. The purpose of this case is to increase awareness and improve management of patients who are treated with denileukin diftitox with resulting vascular leak syndrome leading to hypoalbuminemia. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Essential thrombocythemia, polycythemia vera, and myelofibrosis: Current management and the prospect of targeted therapy
Authors: Tefferi Ayalew
Published: February 2008

The recent discovery of JAK2 and/or MPL mutations in polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has had a major impact on how we diagnose and treat these disorders. For instance, the presence of a JAK2 mutation is now considered conditio sine qua non for the diagnosis of PV and the World Health Organization classification system has recently revised its diagnostic criteria for PV, ET, and PMF to include JAK2 and MPL mutations as clonal markers. From the standpoint of treatment, JAK‐STAT is now identified as a legitimate target pathway for drug development in myeloproliferative neoplasms. Herein, I will first outline my views regarding current management in ET, PV, and PMF and then discuss emerging data on preclinical and clinical activity of anti‐JAK2 small molecule drugs. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Anionic surfactant‐aided preparation of high surface area and high thermal stability ceria/zirconia‐mixed oxide from cerium and zirconium glycolates via sol–gel process and its reduction property
Authors: Rumruangwong M. , Wongkasemjit S.
Published: February 2008

This work is focused on the ceria zirconia mixed oxide prepared through a surfactant‐introduced synthesis method. High surface area nanoparticle mesoporous ceria/zirconia‐mixed oxide was successfully synthesized and characterized using various techniques. High surface area mesoporous fluorite‐structured CeO2ZrO2 was obtained from the elimination of surfactants upon calcination. A surface area in excess of 205.6 m2/g was obtained after calcination at 500 °C, and dropped to 75.96 m2/g by heating at 900 °C. Temperature‐programming reduction (TPR) results showed that the lowest reduction temperature was obtained from the sample containing 40% zirconia content. Copyright © 2008 John Wiley & Sons, Ltd.
Helicity Induction and Memory of the Macromolecular Helicity in a Polyacetylene Bearing a Biphenyl Pendant
Authors: Maeda Katsuhiro , Tamaki Shinji , Tamura Kazumi , Yashima Eiji
Published: February 2008

A novel, cis‐transoidal poly‐(phenylacetylene) bearing a carboxybiphenyl group as the pendant (poly‐1) was prepared by polymerization of (4′‐ethoxycarbonyl‐4‐biphenylyl)acetylene with a rhodium catalyst followed by hydrolysis of the ester groups. Upon complexation with various chiral amines and amino alcohols in dimethyl sulfoxide (DMSO), the polymer exhibited characteristic induced circular dichroism (ICD) in the UV/Vis region due to the predominantly one‐handed helix formation of the polymer backbone as well as an excess of a single‐handed, axially twisted conformation of the pendant biphenyl group. Poly‐1 complexed with (R)‐2‐amino‐1‐propanol showed unique time‐dependent inversion of the macromolecular helicity. Furthermore, the preferred‐handed helical conformation of poly‐1 induced by a chiral amine was further “memorized” after the chiral amine was replaced with achiral 2‐aminoethanol or n‐butylamine in DMSO. In sharp contrast to the previously reported memory in poly((4‐carboxyphenyl)acetylene), the present helicity memory of poly‐1 was accompanied by memory of the twisted biphenyl chirality in the pendants. Unprecedentedly, the helicity memory of poly‐1 with achiral 2‐aminoethanol was found to occur simultaneously with inversion of the axial chirality of the biphenyl groups followed by memory of the inverted biphenyl chirality, thus showing a significant change in the CD spectral pattern.
Remodelling of adipose tissue during experimental omental adhesion formation
Authors: Wilkosz S , Epstein J , de Giorgio-Miller A , McLean W , Ireland G , Herrick S
Published: February 2008

Background

Peritoneal adhesions are fibrous bands of tissue connecting normally separated organs and frequently involve the fat-laden greater omentum. Remodelling of fibrin-rich exudate under reduced fibrinolytic conditions is thought to initiate adhesion formation following surgery. It is unclear whether adhesions that involve the omentum develop in a similar manner. To improve understanding of omental adhesion formation, adipose tissue distribution, cell proliferation and procollagen type I gene expression were investigated in a murine surgical model and in established omental adhesions from patients undergoing abdominal surgery.

Methods

Experimental murine omental adhesions and human omental adhesions were analysed for signs of tissue remodelling using histology, immunohistochemistry and in situ hybridization.

Results

Murine omental tissue showed intense inflammation and reduced adipose tissue 3–7 days after surgery, but increased cellularity and collagen production. Adipose tissue remodelling was reversible with increased adipose tissue and decreased cell proliferation and procollagen type I gene expression, shown by proliferating cell nuclear antigen immunolocalization and in situ hybridization respectively. Human omental adhesions were heterogeneous, with varying amounts of fibrotic and adipose-rich regions, although most displayed proliferating and collagen-producing cells.

Conclusion

Omental adhesions are not static scar tissue as traditionally thought, but undergo active adipose tissue remodelling over-time.
Functional results of intersphincteric resection for low rectal cancer (Br J Surg 2007; 94: 1272–1277)
Authors: Williams N S , Bhan C , Murphy J
Published: February 2008

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved,appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Solid‐Phase Synthesis of Peptide and Glycopeptide Thioesters through Side‐Chain‐Anchoring Strategies
Authors: Ficht Simon , Payne Richard J. , Guy Richard T. , Wong Chi‐Huey
Published: February 2008

An efficient new strategy for the synthesis of peptide and glycopeptide thioesters is described. The method relies on the side‐chain immobilization of a variety of Fmoc‐amino acids, protected at their C‐termini, on solid supports. Once anchored, peptides were constructed using solid‐phase peptide synthesis according to the Fmoc protocol. After unmasking the C‐terminal carboxylate, either thiols or amino acid thioesters were coupled to afford, after cleavage, peptide and glycopeptide thioesters in high yields. Using this method a significant proportion of the proteinogenic amino acids could be incorporated as C‐terminal amino acid residues, therefore providing access to a large number of potential targets that can serve as acyl donors in subsequent ligation reactions. The utility of this methodology was exemplified in the synthesis of a 28 amino acid glycopeptide thioester, which was further elaborated to an N‐terminal fragment of the glycoprotein erythropoietin (EPO) by native chemical ligation.