bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of Outpatients Regarding the Attire of Physiotherapists
Authors: Mercer Erin , MacKay-Lyons Marilyn , Conway Nicki , Flynn Jennifer , Mercer Chris
Published: November 2008

Purpose: This study investigated perceptions of patients regarding physiotherapists’ attire.

Methods: Three hundred patients in three publicly funded outpatient physiotherapy clinics were asked to complete a questionnaire, ranking four photographed modes of attire (lab coat, tailored dress, “scrubs,” and jeans) in terms of professionalism, preference, and appropriateness and rating their level of agreement with four statements about physiotherapists’ attire.

Results: Response rate was 63.7 %. The lab coat was ranked most professional, tailored dress most preferred, and jeans least professional and least preferred. Although jeans were deemed inappropriate (p < 0.001), strong support was shown for wearing jeans on “casual day” (p = 0.001). Age of respondents influenced the perception of the appropriateness of wearing jeans (p = 0.007 for male therapist; p = 0.017 for female therapist); only the cohort <36 years considered jeans appropriate apparel. Overall exposure to physiotherapists (number of lifetime visits) affected patients’ perceptions of the importance of attire (p = 0.039) and the appropriateness of wearing jeans (p = 0.018): as number of visits increased, perceived importance decreased and perceived propriety of jeans increased.

Conclusion: The findings of this study, the first to examine patients’ opinions of physiotherapists’ attire, suggest that outpatients made clear distinctions between what they perceived as professional and what they preferred, as well as between the appropriateness of physiotherapists’ wearing jeans in general and the appropriateness of their doing so on “casual day.” Age and exposure to physiotherapists influenced patients’ perceptions of attire.
Exercise for Fall Risk Reduction in Community-Dwelling Older Adults: A Systematic Review
Authors: Arnold Catherine M. , Sran Meena M. , Harrison Elizabeth L.
Published: November 2008

Purpose: To evaluate the influence of exercise on falls and fall risk reduction in community-dwelling older adults and to present an updated synthesis of outcome measures for the assessment of fall risk in community-dwelling older adults.

Method: A systematic review was performed, considering English-language articles published from 2000 to 2006 and accessible through MEDLINE, CINAHL, PEDro, EMBASE, and/or AMED. Included were randomized controlled clinical trials (RCTs) that used an exercise or physical activity intervention and involved participants over age 50. Screening and methodological quality for internal validity were conducted by two independent reviewers.

Results: The search retrieved 156 abstracts; 22 articles met the internal validity criteria. Both individualized and group exercise programmes were found to be effective in reducing falls and fall risk. The optimal type, frequency, and dose of exercise to achieve a positive effect have not been determined. A variety of outcome measures have been used to measure fall risk, especially for balance.

Conclusions: Falls and fall risk can be reduced with exercise interventions in the community-dwelling elderly, although the most effective exercise variables are unknown. Future studies in populations with comorbidities known to increase fall risk will help determine optimal, condition-specific fall-prevention programmes. Poor balance is a key risk factor for falls; therefore, the best measure of this variable should be selected when evaluating patients at risk of falling.
Dynamic Late Lane Merge System at Freeway Construction Work Zones
Authors: Grillo Lia F. , Datta Tapan K. , Hartner Catherine
Published: November 2008

In normal work zones with lane closures, drivers do not merge at any one definite point, a situation thus often causing a sudden interruption in traffic flow and sometimes higher delay and longer queue. The Dynamic Late Lane Merge System (DLLMS) is used to specify a definite merge point, improve the flow of congested work zones, and reduce queue lengths in travel lanes. The DLLMS was implemented in Michigan on three freeway segments that were reduced from two lanes to one lane because of highway construction work zones. The DLLMS directed traffic to use both lanes (open and closed lanes) until the designated “merge point” (close to the taper) where traffic from each lane was instructed to take turns merging into the open lane. On the basis of travel time characteristics, merge locations, and throughput, the effectiveness of the DLLMS was evaluated as a part of this study. The before period data were not available; therefore, a conventional work zone merge system, located on eastbound I-94, was used as a control site for the westbound I-94 test site. Comparison of the I-94 control and test sites indicated that the presence of the DLLMS improved the flow of travel and increased the percentage of vehicles that merged at or near the designated taper location. Based on the expected travel time savings, at a $5/h value of time, the benefit-cost ratio will be greater than 1, indicating that the monetary benefits of the DLLMS outweigh the cost of the system.
Methodology for Computing Delay and User Costs in Work Zones
Authors: Chitturi Madhav V. , Benekohal Rahim F. , Kaja-Mohideen Ahmed-Zameem
Published: November 2008

A step-by-step methodology for computing delays and user costs in highway work zones is presented in this paper. The methodology is based on the relationship between speed and capacity in work zones. Speed is adjusted to account for the adverse effects of roadway geometrics, work intensity, speed enforcement, and other work zone factors. Speed reductions for work intensity and narrow lane widths were determined previously by use of data from work zones. Values from the Highway Capacity Manual were used where data from work zones were not available. The fundamental difference between this methodology and previous approaches is that it accounts for the various work zone factors. Two applications of the methodology are presented, one with queuing and one without queuing, to real-world work zones. Results are compared with field data. For the nonqueuing site, the computed speed and capacity were 44.4 mph and 1,778 vehicles per hour per lane (vphpl), respectively, while the field speed and capacity were 44 mph and 1,708 vphpl, respectively. For the queuing site, computed capacity was 1,012 vphpl while the field capacity was 1,220 vphpl. Considering the assumptions made in the methodology for some of the parameters, these results build confidence in the methodology. Extensive validation of this methodology is strongly recommended.
Current Asset Management Practices Applied to Pavement Markings
Authors: Markow Michael J.
Published: November 2008

While the principles and methods of asset management are often illustrated by pavement and bridge examples, the approach applies to other components of the transportation system as well. The objective of NCHRP Synthesis Topic 37-03 was to identify current U.S. and international practices in asset management for six classes of nonpavement, nonbridge infrastructure assets: traffic signals, signing, lighting, pavement markings, culverts, and sidewalks. Addressed are the study's findings in regard to pavement markings specifically. Several aspects of asset management were reviewed, including approaches to asset maintenance, budgeting methods, ways of measuring asset performance, estimates of asset service life, materials usage, information technology support, and perceived knowledge gaps and research needs. Study findings indicated that while there is basic agreement on the value of pavement markings, variations in agency management practice, site conditions, and estimates of service life for different marking materials make it difficult to build a consistent body of knowledge. Issues surrounding the different types of retroreflec-tometers in use and the reliability and repeatability of their measurements complicate the situation. As a result, key elements of an asset management approach, such as deterioration models for predicting performance and cost, have not yet been developed with wide acceptance and use. Nevertheless, several efforts have been undertaken that may overcome these problems in the future.
Fracture-Based Friction Model for Pavement Interface Characterization
Authors: Ozer Hasan , Al-Qadi Imad L. , Leng Zhen
Published: November 2008

This paper presents a friction model that characterizes pavement layer interfaces. This model has been built on the basis of three major parameters, shear strength, interface reaction modulus, and friction, to define the behavior of tack coat interfaces. The most important property of this model is its ability to capture the entire range of interface responses, from the fully bonded (initial elastic) interface response to the response in the fully debonded state. A fracture-based elastoplastic constitutive relationship has been implemented for a frictional interface model. Debonding, which can occur in various modes (pure tensile, pure shear, shear with tension, and shear with compression), was formulated by use of a nonlinear softening model integrated into an elastoplastic constitutive model. The pressure dependency of the interface shear strength and dilation because of the surface irregularities are two of the frictional properties examined by the model. The paper includes several numerical examples to illustrate the model's extensive capabilities. The approach followed here involved derivations of the elastoplastic rate equations and integration algorithms and the development of interface elements. Next was the integration in ABAQUS software of algorithms and the interface elements as user elements. The parameters required for the model were obtained through a series of direct shear tests conducted with hot-mix asphalt (HMA)–concrete and HMA–HMA specimens bonded with different tack coat materials. The effects of temperature, normal pressure, and tack coat application rates were also characterized by use of the frictional constitutive model. The use of this model, with its inherent frictional nature, is desirable for interface problems, especially under various loading conditions (pure tensile, pure shear, shear with compression, and shear with tension).
Determination of Asphalt Mixture Creep Compliance at Low Temperatures by Using Thin Beam Specimens
Authors: Zofka Adam , Marasteanu Mihai O. , Turos Mugurel
Published: November 2008

The thermal cracking (TC) module (TCMODEL) of the recently developed Guide for Mechanistic–Empirical Design of New and Rehabilitated Pavement Structures (referred to as MEPDG) is used to predict thermally induced cracking in asphalt pavements over their service lives. The primary input to this model is the asphalt mixture creep compliance. The current standard test for determination of the creep compliance of asphalt mixtures is the indirect tensile test (IDT). This paper investigates the feasibility of using the bending beam rheometer (BBR) device to determine the low-temperature creep compliance of thin asphalt mixture beams (127 × 12.7 × 6.35 mm). The BBR device was used to evaluate 20 different asphalt mixtures, and the results were compared with the standard IDT results. Direct comparison of the BBR and the IDT results indicated that both methods produce slightly different creep compliance curves and that the relative ratio between the BBR and the IDT results varies with time and temperature. A simple phenomenological relation that gives good predictions of the IDT results on the basis of BBR creep compliance is proposed. The measured and predicted creep compliance curves were input into the MEPDG TC module, and the predicted depth of cracks and the amount of cracking were compared. The comparison showed that predicted creep compliance determined on the basis of the BBR results can be successfully used to estimate thermal cracking by use of the TCMODEL. It was concluded that the BBR device can be used for the practical and surrogate estimation of the creep compliance of mixtures. The proposed equation relating BBR and IDT creep compliances should be further validated with different types of mixtures.
Fatigue Analysis of Asphalt Mixtures Independent of Mode of Loading
Authors: Castelo Branco Veronica T. F. , Masad Eyad , Bhasin Amit , Little Dallas N.
Published: November 2008

Fatigue cracking is a common form of distress in asphalt pavements. During the last four decades, significant research has been conducted to characterize fatigue damage in asphalt mixtures. This paper evaluates an analytical method that is independent of the mode of loading (controlled strain or controlled stress) to quantify the fatigue resistance of asphalt mixtures. The evaluation was based on fatigue tests conducted on the fine aggregate matrix (FAM) portion of an asphalt mixture by using a dynamic mechanical analyzer. A number of tests were performed by applying oscillatory torque under controlled-strain and controlled-stress conditions at a frequency of 10 Hz and a temperature of 25°C. The data from these tests were analyzed by using a fracture model for viscoelastic materials to calculate a fatigue damage parameter, R(N), which represents the influence of the numbers of cracks with equivalent crack radii on the material fracture behavior and which quantifies crack growth in FAM. This damage parameter has a coefficient of variation lower than the coefficients of variation of conventional parameters, such as the number of load cycles to failure and the cumulative dissipated energy. In addition, this parameter provides comparable results for a given material independent of the mode of loading.
Using the Planning and Environment Linkages Umbrella Approach to Streamline Transportation Decision Making
Authors: Barberio Gina , Barolsky Rachael , Culp Michael , Ritter Robert
Published: November 2008

The planning and environment linkages (PEL) umbrella approach is designed to streamline the process of project development and environmental review by encouraging agencies to take an integrated, systems perspective to support transportation, environmental, and community goals. The PEL approach provides strategies, practices, processes, and analytical tools that encompass related federal activities including linking planning and the National Environmental Policy Act (NEPA), ecological and context-sensitive solutions, corridor planning, and integrated planning. When successfully implemented, the PEL approach makes the entire life cycle of a project a more seamless process, from planning to NEPA and on to design, construction, and maintenance. The PEL approach is described, federal legislation and related activities are discussed, examples of effective practices are provided, lessons learned are shared, and the reader is directed to additional resources for implementation.
Real-World Carbon Dioxide Impacts of Traffic Congestion
Authors: Barth Matthew , Boriboonsomsin Kanok
Published: November 2008

Transportation plays a significant role in carbon dioxide (CO2) emissions, accounting for approximately a third of the U.S. inventory. To reduce CO2 emissions in the future, transportation policy makers are planning on making vehicles more efficient and increasing the use of carbon-neutral alternative fuels. In addition, CO2 emissions can be lowered by improving traffic operations, specifically through the reduction of traffic congestion. Traffic congestion and its impact on CO2 emissions were examined by using detailed energy and emission models, and they were linked to real-world driving patterns and traffic conditions. With typical traffic conditions in Southern California as an example, it was found that CO2 emissions could be reduced by up to almost 20% through three different strategies: congestion mitigation strategies that reduce severe congestion, allowing traffic to flow at better speeds; speed management techniques that reduce excessively high free-flow speeds to more moderate conditions; and shock wave suppression techniques that eliminate the acceleration and deceleration events associated with the stop-and-go traffic that exists during congested conditions.
Use of the Micro-Deval Test for Assessing Fine Aggregate Durability
Authors: Hossain M. Shabbir , Lane D. Stephen , Schmidt Benjamin N.
Published: November 2008

The Micro-Deval test was evaluated for its suitability in assessing the durability of fine aggregate from Virginia sources. Fine aggregates from 10 sources with known performance histories were tested with the Micro-Deval and several common aggregate quality methods. The Canadian Micro-Deval testing protocol for fine aggregates was followed. The results obtained with the Micro-Deval test showed better precision than those obtained with the conventional aggregate tests. In terms of field performance rating, the Micro-Deval test was able to differentiate between good- and poor-performing aggregates at least 80% of the time and was able to identify differences in quality between similar aggregate types with varying degrees of weathering. The Micro-Deval test is recommended as a quality control tool for fine aggregate assessment to supplement the current measures of aggregate quality. After sufficient data have been gathered and compared with data regarding field performance, it may be possible to replace the existing soundness or freeze–thaw tests with the Micro-Deval test.
Material Factors that Influence Anisotropic Behavior of Aggregate Bases
Authors: Salehi Reza , Little Dallas N. , Masad Eyad
Published: November 2008

The directional dependency of material properties of aggregate systems have been the subject of study over the last 10 years. A procedure was established to determine the level of anisotropy of aggregate systems using simple aggregate properties and anisotropy level as an input to predict performance of aggregate bases. Stress-induced directional dependency of material properties were evaluated on the basis of multiple variable dynamic confining pressure stress path tests for 10 aggregate sources. Various gradations and saturation levels were considered for each aggregate source. Particle geometry was characterized using the Aggregate Imaging System. The cumulative Weibull distribution function was used to describe aggregate size and aggregate geometrical characteristics. The fine portion of the gradation was characterized by the Rigden voids test and methylene blue test to account for fine particle shape properties and the deleterious effect of plastic fines on the volumetric stability of aggregate layers. The cross-anisotropic modular ratios were used as indicators of the level of anisotropy. Aggregate characteristics (form, angularity, texture, and gradation) are in turn related to Weibull cumulative distribution parameters. A sensitivity analysis revealed that the level of anisotropy is very sensitive to aggregate form, angularity, and textural properties. It is also sensitive to the level of bulk stress and shear stress as reflected by the k2 and k3 parameters. Cross-anisotropic shear strength ratios for four pavement sections at the top of the base layer were calculated using a finite element program. The results indicated that the level of anisotropy significantly affected the shear strength ratio.
Permanent Deformation Behavior of Naturally Occurring Bituminous Sands
Authors: Anochie-Boateng Joseph , Tutumluer Erol , Carpenter Samuel H.
Published: November 2008

Oil sand, or tar sand, is a generic name given to bituminous sand deposits that are rich in bitumen or asphalt content to the extent that oil can be extracted from these deposits. The typical 8% to 15% presence of bitumen in the soil composition makes these naturally occurring sands low load-bearing materials. In this study, repeated load triaxial tests were conducted on three types of oil sand materials with natural bitumen contents of 8.5%, 13.3%, and 14.5% by weight. The oil sand specimens were compacted close to field densities and then tested for permanent deformation at two temperatures using a newly proposed test procedure. The procedure applied stress states and ratios determined from field-loading characteristics of haul trucks and mining equipment at two different load pulse durations or loading frequencies (related to field-trafficking speeds). Both the test data and axial permanent strain models developed in the form of power functions of the number of repeated load applications indicated a strong dependency of oil sand permanent strain development on the applied vertical to horizontal (or major to minor principal) stress ratio. Using the test data, permanent strain and deformation models were developed with high correlation coefficients to account for the applied stress states and ratios, test temperature, and bitumen content. These models generalized for oil sand deformation behavior may be used as practical predictive equations to estimate the amount of rutting in oil sand materials and to alleviate potential sinkage problems faced by off-road haul trucks, shovels, and other mining equipment in the field.
Rapid Assessment of Cement and Fiber-Stabilized Soil Using Roller-Integrated Compaction Monitoring
Authors: Newman J. Kent , White David J.
Published: November 2008

Test sections of high-early strength (Type III) portland cement and polypropylene monofilament fibers were constructed at the Bradshaw Field Training Area in the Northern Territory (NT), Australia as part of a Joint Rapid Airfield Construction (JRAC) project. Aprons, taxi-ways, and a helipad were stabilized using these materials in combination with screened native soil. The purpose of the test sections was to (a) evaluate the resulting properties for different stabilization dosage rates; (b) develop construction methods, criteria (including limits), and quality control guidelines; and (c) provide a hands-on training opportunity for the joint United States and Australia military construction team. Testing and monitoring consisted of roller-integrated compaction monitoring (global position systems monitoring pass coverages and compaction machine values) and in situ testing, which included dynamic cone penetration tests, Clegg impact tests, and light-weight deflectometer tests. After the test sections, construction of the helipad helped refine the construction methods and quality control testing for the selected stabilization dosage rates and machine speed. Lessons learned on the helipad were applied to the subsequent aircraft parking aprons and taxiways. Recommendations were developed for rapid stabilization construction procedures and quality control testing using Clegg impact values and light-weight deflectometer for cement-fiber stabilized soils, and the application of roller-integrated compaction technology was demonstrated to document compaction effort and uniformity.
Assessment of Sag Curve Design Criteria considering Modern Headlamp Performance
Authors: Gene Hawkins H. , Gogula Madhuri
Published: November 2008

For more than 50 years, headlight sight distance has been one method for calculating the length of sag vertical curves; the others are passenger comfort, drainage control, and general appearance. The headlight sight distance is based on a 1° upward divergence of the headlamp beam. Over the past 20 years, headlamps have transitioned from being 100% sealed beam to modern replaceable bulb headlamps that project less light above the horizontal plane than the sealed-beam headlamps that are the basis for sag curve design. This paper describes theoretical and field measurements of the illuminance levels provided by sealed-beam and modern headlamps. The results of the analysis indicate that modern headlamps provide significantly less light above the horizontal than sealed-beam headlamps, indicating a potential need to modify the design equations for sag vertical curves. According to the theoretical analysis, the upward divergent headlamp angle used in the sag curve design equation should be reduced from 1° to between 0.75° and 0.90°. The field analysis indicated a significant difference in illuminance levels from the theoretical analysis, but the results also indicate a need to reduce the headlamp angle used in sag curve design.
Three-Dimensional, Probabilistic Highway Design
Authors: Sarhan Mohamed , Hassan Yasser
Published: November 2008

The potential usefulness of reliability analysis has recently been stressed in many engineering applications. Given the variability in the design parameters, a reliability-based probabilistic approach is well suited to replace the current deterministic highway design practice. However, progress in this regard is generally slow. In this study, the reliability analysis was used to estimate the probability of hazard (POH) that might result from insufficiency of sight distances. As an application, the available sight distance was checked against required stopping sight distance on an assumed road segment. Variation of the design parameters was addressed with Monte Carlo simulation using 100,000 sets of design parameters based on distributions available in the literature. A computer program was developed to use these sets of design parameters to calculate the profiles of available and required stopping sight distances in two- and three-dimensional projections as well as the profile of POH. The approach was applied to a horizontal curve overlapping with flat grade, crest curves, and sag curves in a cut section where the side slope would restrict the sightline. The analysis showed that the current deterministic approach yields very conservative estimates of available and required stopping sight distance, resulting in very low POH. The application example also showed the change of POH with the change of vertical alignment parameters.
Effect of Median Design on Rural Freeway Safety
Authors: Tarko Andrew P. , Villwock Natalie M. , Blond Nicolas
Published: November 2008

Although median barriers are an absolute means of preventing drivers from crossing road medians and colliding with vehicles moving in the opposite direction, they may cause additional crashes. This perhaps complex safety effect of median barriers has not been investigated well. Being able to predict the safety impact of most types of median barriers on rural freeways is becoming more desirable because some state departments of transportation plan to expand many of their four-lane rural freeways to six lanes to accommodate increases in traffic volume. Realistic crash prediction models sensitive to the median design would provide the needed guidance useful in designing adequate median treatments on widened freeways. The impact of median designs on crash frequency was investigated in this study through negative binomial regression and before-and-after studies based on data collected in eight participating states. The impact on crash severity was investigated with a logit model. The separate effects of changes in median geometry were quantified for single-vehicle, multiple-vehicle same direction, and multiple-vehicle opposite direction crashes. The results were significantly different and indicated that reducing the median width without adding barriers (the remaining median width is still reasonably wide) increases the severity of crashes, particularly opposite direction crashes. Further, reducing the median and installing concrete barriers eliminates opposite direction crashes but doubles the frequency of single-vehicle crashes and tends to lessen the frequency of same direction crashes. The crash severity also tends to increase.
From Arterial to Asset
Authors: Gillem Mark L.
Published: November 2008

Cities struggling with congestion need options to automobile-dependent transportation and land use patterns. Multiway boulevards are one alternative. Through lanes in the middle are separated by landscaped medians from side access lanes for bicycles and slow-moving local traffic. Using a case study from Oregon's Eugene–Springfield metropolitan area, this project considers what could happen if cities built arterials as multiway boulevards. This interdisciplinary study, which included widespread stakeholder and public participation as well as detailed land use and transportation modeling, was instrumental in the Eugene Planning Commission's decision to endorse converting a portion of the arterial into a multiway boulevard. Although the case study arterial, with its existing bus rapid transit lanes, requires an unusually wide right-of-way, the results show that the arterial could better accommodate residential and mixed-use buildings at the edges if reconfigured as a multiway boulevard. Projected benefits include the possibility of supporting 8,400 dwelling units, reducing annual vehicle miles traveled by nearly 100 million miles (161 million km), and reducing annual carbon emissions by nearly 110 million lb (50 million kg). Development along the boulevard can preserve up to 1,680 acres (680 ha) of farmland and lead to an annual transportation savings per household of about $1,500. New residences could generate more than $17 million annually in property tax revenue. This study offers lessons for communities interested in promoting environmental protection, enhancing quality of life, and reducing energy consumption.
Construction Specification Framework for Utility Installations
Authors: Quiroga Cesar , Ford David , Taylor Timothy , Kranc Stanley , Kraus Edgar
Published: November 2008

Utility accommodation policies nationwide contain requirements for the accommodation, location, installation, relocation, and maintenance of utility facilities on the state right-of-way. The policies normally cover basic requirements, making it necessary to use additional specifications and special provisions to handle situations not covered by the policies. Frequently, because of the lack of standard utility installation construction specifications at transportation agencies, many different versions of special specifications and special provisions exist. Closely related to the need to standardize construction specifications for utility installations is the need to standardize methodologies and procedures for determining the cost of utility relocation. This lack of standardization translates into difficulties such as how to verify the validity of the cost data submitted for reimbursement and how to prepare adequately for audits and other internal and external inquiries. This paper summarizes the work completed to develop a prototype framework of construction specification requirements for utility installations, with a focus on water, sanitary sewer, and communication specifications. The specification framework includes five groups of specifications: earth work, pipes and boxes, appurtenances, other, and general (including specifications such as mobilization and traffic control, which highway construction contracts typically include but are also relevant to the utility relocation process). The framework uses tables that summarize the main characteristics of proposed new and modified standard specifications and includes a listing of pay items, subsidiary items, and corresponding measurement units. The framework also includes specification requirements.
Effects of Varying Dispersion Parameter of Poisson–Gamma Models on Estimation of Confidence Intervals of Crash Prediction Models
Authors: Geedipally Srinivas Reddy , Lord Dominique
Published: November 2008

In estimating safety performance, the most common probabilistic structures of the popular statistical models used by transportation safety analysts for modeling motor vehicle crashes are the traditional Poisson and Poisson–gamma (or negative binomial) distributions. Because crash data often exhibit overdispersion, Poisson–gamma models are usually the preferred model. The dispersion parameter of Poisson–gamma models had been assumed to be fixed, but recent research in highway safety has shown that the parameter can potentially be dependent on the covari-ates, especially for flow-only models. Given that the dispersion parameter is a key variable for computing confidence intervals, there is reason to believe that a varying dispersion parameter could affect the computation of confidence intervals compared with confidence intervals produced from Poisson–gamma models with a fixed dispersion parameter. This study evaluates whether the varying dispersion parameter affects the computation of the confidence intervals for the gamma mean (m) and predicted response (y) on sites that have not been used for estimating the predictive model. To accomplish that objective, predictive models with fixed and varying dispersion parameters were estimated by using data collected in California at 537 three-leg rural unsignalized intersections. The study shows that models developed with a varying dispersion parameter greatly influence the confidence intervals of the gamma mean and predictive response. More specifically, models with a varying dispersion parameter usually produce smaller confidence intervals, and hence more precise estimates, than models with a fixed dispersion parameter, both for the gamma mean and for the predicted response. Therefore, it is recommended to develop models with a varying dispersion whenever possible, especially if they are used for screening purposes.
Cross-Correlation Analysis and Multivariate Prediction of Spatial Time Series of Freeway Traffic Speeds
Authors: Chandra Srinivasa Ravi , Al-Deek Haitham
Published: November 2008

Short-term traffic prediction on freeways is one of the critical components of the advanced traveler information system (ATIS). The traditional methods of prediction have used univariate ARIMA time-series models based on the autocorrelation function of the time series of traffic variables at a location. However, the effect of upstream and downstream location information has been largely neglected or underused in the case of freeway traffic prediction. The purpose of this study is to demonstrate the effect of upstream as well as downstream locations on the traffic at a specific location. To achieve this goal, a section of five stations extending over 2.5 mi on I-4 in the downtown region of Orlando, Florida, was selected. The speeds from a station at the center of this location were then checked for cross-correlations with stations upstream and downstream. The cross-correlation function is analogous to the autocorrelation function extended to two variables. It indicates whether the past values of an input series influence the future values of a response series. It was found in this study that the past values of upstream as well as downstream stations influence the future values at a station and therefore can be used for prediction. A vector autoregressive model was found appropriate and better than the traditional ARIMA model for prediction at these stations.
Construct Validity and Reliability of the Disability ofArm, Shoulder and Hand Questionnaire for Upper Extremity Complaints in Rheumatoid Arthritis
Authors: RAVEN ERIC E.J. , HAVERKAMP DANIËL , SIEREVELT INGER N. , van MONTFOORT DOUWE O. , PÖLL RUUD G. , BLANKEVOORT LEENDERT , TAK PAUL P.
Published: November 2008

Objective

The Disability of Arm, Shoulder and Hand (DASH) questionnaire is a tool for measuring physical function and symptoms of the upper extremity. Although widely used, it is not validated for rheumatoid arthritis (RA). In this study the DASH was validated for this patient group.

Methods

In total, 102 patients participated in this study. For the validation, the questionnaires of the DASH, the Health Assessment Questionnaire (HAQ), the Medical Outcomes Study Short Form-36 (SF-36), and the Arthritis Impact Measurement Scale (AIMS2) were used. Patients were examined clinically before completing the questionnaires. Pain was scored by each patient using a visual analog scale (VAS). The DiseaseActivity Score (DAS28) was obtained and grip strength was measured. Reliability was tested by a second DASH questionnaire after 2 days. Validity was tested using a Pearson correlation analysis for the relevant domains of the questionnaires and for the clinical aspects.

Results

The reliability of the DASH was excellent (intraclass correlation coefficient 0.97). Internal consistency was strong (Cronbach’s alpha 0.97). Validity was proven with excellent results for Pearson correlation with the relevant domains of the questionnaires: HAQ, r = 0.88; SF-36, r = 0.70; and AIMS2, r = 0.85. The clinical scores had a relatively low correlation with the DASH (DAS28, r = 0.42; and grip strength, r = 0.41–0.48), except for the VAS (r = 0.60–0.65).

Conclusion

The DASH is a reliable and valid questionnaire in patients with RA. It can be used as a measurement tool of physical disability of the upper extremity.
Predicting Patient Dissatisfaction Following Joint Replacement Surgery
Authors: GANDHI RAJIV , DAVEY J. RODERICK , MAHOMED NIZAR N.
Published: November 2008

Objective

The incidence of patient-reported dissatisfaction following total joint arthroplasty can be up to 30%. Our aim was to identify the preoperative patient-level predictors of patient dissatisfaction 1 year after surgery.

Methods

We surveyed 1720 patients undergoing primary hip or knee replacement surgery. Relevant covariates including demographic data, body mass index, sex, comorbidities, and education were recorded. Joint functional status and patient quality of life were assessed at baseline and at 1-year followup with the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and Medical Outcomes Study Short Form-36 (SF-36) scales, respectively. Patient satisfaction with surgery was determined with 4 survey questions at 1-year followup.

Results

There were no significant differences in demographic data between satisfied (n = 1290) and dissatisfied patients (n = 430). Logistic regression modeling showed that a lower preoperative SF-36 Mental Health score independently predicted patient dissatisfaction with surgery, adjusted for all relevant covariates (p < 0.05). We found no correlation between patient satisfaction and WOMAC change scores at 1-year followup (p = 0.31).

Conclusion

Preoperative mental health is an important factor to consider when understanding patient satisfaction with surgery. Interventions to reduce psychological distress prior to surgery should be studied to determine if they may improve subjective outcomes of patients undergoing joint replacement surgery.
Elevated Serum Insulin-like Growth Factor (IGF-1) and IGF Binding Protein-3 Levels in Patients with Systemic Sclerosis: Possible Role in Development of Fibrosis
Authors: HAMAGUCHI YASUHITO , FUJIMOTO MANABU , MATSUSHITA TAKASHI , HASEGAWA MINORU , TAKEHARA KAZUHIKO , SATO SHINICHI
Published: November 2008

Objective

To examine serum concentrations of insulin-like growth factor (IGF-1) and IGF binding protein (IGFBP-3), a major carrier protein for IGF-1, in patients with systemic sclerosis (SSc); and to relate the results to clinical features in SSc.

Methods

Serum IGF-1 and IGFBP-3 levels in 92 Japanese patients with SSc were measured by ELISA. Expression of IGF-1 and IGFBP-3 messenger RNA (mRNA) in the skin was quantified by real-time reverse transcription-polymerase chain reaction.

Results

Serum IGF-1 and IGFBP-3 levels were significantly elevated in patients with SSc compared with patients with systemic lupus erythematosus or healthy controls. IGF-1 levels were higher in patients with diffuse cutaneous SSc (dcSSc) than in patients with limited cutaneous SSc (lcSSc). Patients with increased IGF-1 levels had more severe skin involvement and pulmonary fibrosis. IGF- 1 mRNA was upregulated in the affected skin of patients with SSc. There were no significant differences in serum IGFBP-3 levels between dcSSc and lcSSc. IGFBP-3 levels were not associated with skin thickness and pulmonary fibrosis. Patients with increased IGF-1 or IGFBP-3 had lower frequency of telangiectasia than patients with normal levels.

Conclusion

These results suggest that both IGF-1 and IGFBP-3 are involved in the development of SSc. The role of IGF-1 appears to be different from that of IGFBP-3.
Setting a public health research agenda for Down syndrome: Summary of a meeting sponsored by the Centers for Disease Control and Prevention and the National Down Syndrome Society
Authors: Rasmussen Sonja A. , Whitehead Nedra , Collier Sarah A. , Frías Jaime L.
Published: November 2008

On November 8–9, 2007, a meeting entitled “Setting a Public Health Research Agenda for Down Syndrome” was held to review current knowledge, identify gaps, and develop priorities for future public health research related to Down syndrome. Participants included experts in clinical and molecular genetics, pediatrics, cardiology, psychiatry, psychology, neuroscience, epidemiology, and public health. Participants were asked to identify key public health research questions and discuss potential strategies that could be used to address those questions. The following were identified as priority areas for future public health research: identification of risk and preventive factors for physical health and cognitive outcomes, focusing on understanding the reasons for previously recognized disparities; improved understanding of comorbid conditions, including their prevalence, clinical variability, natural history, and optimal methods for their evaluation and treatment; better characterization of the natural history of cognition, language, and behavior; identification of mental health comorbidities and of risk and protective factors for their development; identification of strategies to improve enrollment in research studies; development of strategies for conveying up‐to‐date information to parents and health professionals; identification of interventions to improve cognition, language, mental health, and behavior; understanding the impact of educational and social services and supports; identification of improved methods for diagnosis of and interventions for Alzheimer disease; and understanding the effects of different types of health care on outcomes. Participants strongly supported the development of population‐based resources for research studies and resources useful for longitudinal studies. This agenda will be used to guide future public health research on Down syndrome. Published 2008 Wiley‐Liss, Inc.
Social influence on predictions of simulated stock prices
Authors: Andersson Maria , Hedesström Ted Martin , Gärling Tommy
Published: November 2008

Herding in financial markets refers to that investors are influenced by others. This study addresses the importance of consistency for herding. It is suggested that, in financial markets perceptions of consistency are based on repeated observations over time. Consistency may then be perceived as the agreement across time between investors' predictions. In addition, consistency may be related to variance over time in each investor's predictions. In an experiment using a Multiple Cue Probability Learning paradigm, 96 undergraduates made multi‐trial predictions of future stock prices given information about the current price and the predictions made by five fictitious others. Consistency was varied between the others' predictions (correlation) and within the others' predictions (variance). The results showed that the predictions were significantly influenced by the others' predictions when these were correlated. No effect of variance was observed. Hence, participants were influenced by the others when they were in agreement, regardless of whether they varied their predictions over trials or not. Copyright © 2008 John Wiley & Sons, Ltd.
Fracture of a GORE HELEX Septal Occluder following PFO closure in a diver
Authors: Scott Paul , Wilson Neil , Veldtman Gruchen
Published: November 2008

Decompression illness (DCI) is more common in divers with a patent foramen ovale (PFO), and transcatheter PFO closure is being increasingly performed in patients with an episode of DCI who want to continue diving. A range of closure devices are available and the choice in an individual case depends on operator preference and PFO anatomy. The GORE HELEX Septal Occluder, introduced in 1999 primarily for secundum atrial defect closure, is a compliant non self‐centering device composed of a wire helical framework on which a microporous membrane is mounted. The device is fixed in place by a unique interlocking mechanism that passes through the center of the device from the left to the right atrial disc, thereby securing it onto the interatrial septum. Here, we present a case of a locking loop fracture and review the literature concerning this unusual complication. © 2009 Wiley‐Liss, Inc.
Pooled analysis of percutaneous mitral valvuloplasty in Egypt
Authors: Sherif Mohammad A. , Khashaba Ahmed A. , Gomaa Yaser , Khaled Saeed , Refaie Osama , Ramzy Ali
Published: November 2008

Background:

Till now, no pooled analysis summarizing the Egyptian experience in percutaneous mitral valvuloplasty (PMV) exists.

Objectives and Methods:

To pool the data of PMV procedures and perform a new analysis regarding the immediate outcome and follow‐up results as well as to compare the results of different techniques.

Results:

Patients (2,256) with mitral stenosis of rheumatic origin were included, 292 males and 1,964 females. Double balloon (DB) was used in 1,148 patients (51%), Inoue balloon (IB) in 914 patients (40.5%), metallic commissurotome (MC) in 142 patients (6%), Multi‐Track in 33 patients (1.5%), and single balloon in 19 patients (1%). The mitral valve area (MVA) increased from 0.94 ± 0.18 cm2 to 1.92 ± 0.36 cm2; mean pressure gradient dropped from 15.94 ± 5.46 mmHg to 5.85 ± 2.6 mmHg. The most common complication was the occurrence of a new mitral regurgitation (MR) and/or increase in its grade (36%). Inadequate dilatation occurred in 192 patients (8.5%). Follow‐up data (for 5.7 ± 5.9 months) showed that the immediate results of PMV on MVA persisted through the follow‐up period (1.78 ± 0.35 cm2). Multi‐Track system resulted in the largest increase in MVA and also resulted in the largest immediate increase in the grade of MR.

Conclusions:

This study confirms the success of PMV and its results during follow‐up. The Multi‐Track system, and the DB resulted in the largest MVA, the IB and the single balloon resulted in the least increase in MR. The most common complication of PMV is the increase in the degree of MR. © 2009 Wiley‐Liss, Inc.
Light‐Driven Rotary Molecular Motors on Gold Nanoparticles
Authors: Pollard Michael M. , ter Wiel Matthijs K. J. , van Delden Richard A. , Vicario Javier , Koumura Nagatoshi , van den Brom Coenraad R. , Meetsma Auke , Feringa Ben L.
Published: November 2008

We report the synthesis of unidirectional light‐driven rotary molecular motors based on chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of 1H and 13C NMR, UV/Vis and CD spectroscopy, we show that these motors preserve their photochemical and thermal behaviour after they have been attached to gold nanoparticles. Furthermore, we describe the synthesis of 2H‐ and 13C‐labelled derivatives that were used to verify the unidirectionality of the rotary cycle of these motors both in solution and while grafted to gold nanoparticles. Taken together, these data support the conclusion that these motors maintain their unidirectional rotary cycle when grafted to the surface of small (ca. 2 nm) gold nanoparticles. Thus, continuous irradiation of the system under appropriate conditions leads to unidirectional rotation of the upper half of the molecules relative to the entire nanoparticle.