bluuebunny/crossref_metadata_2025 huggingface dataset:
Sill-controlled hydraulic jump in a gradually expanding channel
Authors: Omid M. H. , Gord-Noshahri A. , Kouchakzadeh S.
Published: October 2010

The gradually diverging stilling basin is attractive to the designer due to its compatibility with a large range of upstream and downstream sections, and to having a small sequent depth ratio and jump length. However, the hydraulic jump in such stilling basins often encounters instability and asymmetrical flow problems. In the present study, the effect of broad and sharp-crested sills in improving hydraulic jump characteristics, including sequent depth ratio, jump length and the free surface profile of a jump in a gradually diverging stilling basin was investigated. For this purpose, sills with various heights and different locations relative to the jump toe were installed in stilling basins with diverging angles of 3, 5 and 9°. In total, 284 tests were carried out in the range of initial Froude numbers of 3·1 to 10·4. The results indicate that the end sill has an insignificant effect on the sequent depth ratio, but it may considerably decrease the length of the hydraulic jump. It was also found that the sill could considerably improve the general conditions and features of an expanding hydraulic jump and could stabilise the position of this type of jump.
Precise Adsorption Behavior and Mechanism of Ni(II) ions on Nano‐Hydroxyapatite
Authors: Zhang Jun , Wang Deping , Zhou Jun , Yao Aihua , Huang Wenhai
Published: October 2010

The goal of this study was to synthesize use of hydroxyapatite as a high‐efficiency adsorbent for Ni(II) ions, and to study its adsorption behavior. Three tests— Fourier‐transform infrared spectroscopy, transmission electron microscopy, and Brunauer‐Emmett‐Teller —were carried out to determine the chemical functionality of the hydroxyapatite powders, to observe its crystal morphology, and to measure the specific surface area. Results indicate that proves the n‐HA synthesized by chemical precipitation is an effective adsorbent for the removal of Ni(II) ions from water solution. The synthesized, needle‐like nano‐hydroxyapatite (n‐HA) have a uniform average size of 31.9 × 21.3nm, a large specific surface area (135 m2/g), and typically is a weak crystal with a broad pore distribution. The adsorption isotherm shows the Langmuir model is applicable only when the initial Ni2+ concentration is lower than 0.1 mol/L. Multilayer adsorption was attributed to uneven pore distribution that occurred at higher Ni2+ concentration. The adsorption of Ni2+ onto n‐HA was attributed to electrostatic attraction, ion exchange, and dissolution‐precipitation reaction. As the result, Ni2+ substitutes Ca2+ and binds with the oxygen atom on the surface, which resulted from the change in crystal‐phase composition and in the binding energy of surface elements of n‐HA before and after adsorption.
Influence of Sulfur Concentration on Bioleaching of Heavy Metals from Industrial Waste Sludge
Authors: Lin Yen‐Hui , Juan Mu‐Ling , Huang Hau‐Liang , Tsai Hui‐Ying , Lin Pearl Hsui‐Ping
Published: October 2010

The bioleaching process, including acidification and solubilization of heavy metals, is a promising method for removing heavy metals from industrial waste sludge. Solubilization of heavy metals in industrial waste sludge is governed by adding elemental sulfur. A sulfur concentration exceeding 0.5% (w/v) inhibits sulfate production and the activity of acidophilic bacteria. Sulfate production was described well by a substrate inhibition expression in Haldane's kinetics. After 15 days of bioleaching, 79 to 81% copper, 50 to 69% lead, and 49 to 69% nickel were solubilized from sludge with a sulfur concentration of 0.5 to 1.0% (w/v). Experimental results indicated that the optimal sulfur concentration for the maximum solubilization rate of copper and nickel was 0.5% (w/v) and 1.0% (w/v) for lead. The profiles of denaturing gradient gel electrophoresis confirmed that indigenous acidophilic Acidithiobacilli (A. thiooxidans and A. ferrooxidans) existed and were the dominant species in the bioleaching process.
Survival of Escherichia coli Strains in Mediterranean Brackish Water in the Bizerte Lagoon in Northern Tunisia
Authors: Boukef I. , El Bour M. , Al Gallas N. , El Bahri O. , Mejri S. , Mraouna R. , Ben Aissa R. , Boudabous A. , Got P. , Troussellier M.
Published: October 2010

This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in Northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m2, 26 ± 1 °C, 30 g/L) and in April (227 to 330 W/m2, 17 ± 1 °C, 27 g/L) or maintained in darkness for 21 days (17 ± 1 °C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T90 = 52 hours) than E. coli O126:B16 (T90 = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival.
Phosphorus Speciation in the Surface Sediment and River Water from the Orontes (Asi) River, Turkey
Authors: Aydin Isil , Aydin Firat , Hamamci Candan
Published: October 2010

The paper presents the results of the distribution of phosphorus bioavailability (total, organic, and inorganic phosphorus) in surface sediment and river water from the Orontes (Asi) River (Samandag, Antakya, Turkey) in March 2008. Speciation of inorganic phosphorus was carried out using a method on sequential extractions, with each releasing four forms of inorganic phosphorus—loosely sorbed phosphorus, phosphorus bound to aluminum (P‐Al), phosphorus bound to iron (P‐Fe), and phosphorus bound to calcium (P‐Ca). Total phosphorus concentrations are, on average, 3.724 mg/L and 312.30 mg/kg dry weight in the river water and surface sediment, respectively. The interstitial water of the surface sediment contains less than 1% of the surface sediment's total phosphorus pool. The most abundant form of inorganic phosphorus is P‐Ca. Relative abundances of the remaining phosphorus forms both in surface sediment and river water follow the order P‐Al > loosely bound‐P> P‐Fe.
Model of Radiation Transmittance by Inorganic Fouling on UV Reactor Lamp Sleeves
Authors: Wait Isaac W. , Blatchley Ernest R.
Published: October 2010

The efficacy of UV disinfection of water depends on the ability of radiation to pass from UV lamps through the quartz sleeves that encase them; the accumulation of metal‐containing foulants on sleeve surfaces inhibits disinfection by absorbing radiation that would otherwise be available for inactivation. In a series of experiments, the composition and quantity of sleeve foulants were studied relative to water chemistry and sleeve transmittance. Findings indicate that iron and calcium dominate fouling, with elevated fouling activity by iron, aluminum, manganese, and zinc. A regression‐based modeling approach was used to characterize and quantify the effects of foulant metals on UV absorbance. The molar extinction coefficient for iron was found to be more than 3 times greater than that of calcium. Iron's relatively high activity in fouling reactions, elevated capacity to absorb UV, and reduced solubility under oxidizing conditions makes it a fouling precursor of particular concern, with respect to potential for sleeve fouling in UV reactors.
Soybean Peroxidase‐Catalyzed Removal of an Aromatic Thiol, 2‐Mercaptobenzothiazole, from Water
Authors: Al‐Ansari Mohammad Mousa , Steevensz A. , Taylor K.E. , Bewtra J.K. , Biswas N.
Published: October 2010

This paper demonstrates, for the first time, the capability of soybean peroxidase (SBP), an enzyme, for catalyzing the removal of an aromatic thiol, 2‐mercaptobenzothiazole (MBT), from aqueous solution. The optimum pH for enzymatic conversion of MBT in aqueous buffer was found to be in the range 6.0 to 9.0. The optimum hydrogen peroxide (H2O2):MBT stoichiometry was 0.6. In terms of standard units (U) of catalytic activity, the minimum SBP concentration required for 95% conversion of 1.0 mM MBT in 3 hours was found to be 0.9 U/mL. The presence of polyethylene glycol at 50 mg/L can reduce the enzyme concentration required for the same conversion by 3‐fold. It is proposed that these findings should be the basis for viable and cost‐effective treatment of MBT in industrial wastewater and/or process water.
Social Psychological Factors Affecting the Employment of Graduate Students in Taiwan
Authors: Yang King-Jang , Chen Shun-Hsing , Fan Hsin-I
Published: October 2010

In this study the researchers use principal factor analysis to identify the factors affecting the competitiveness of college graduate students in the job market, based on a sample of senior students enrolled in an undergraduate school. The analysis revealed 5 factors that influence
the students' employment prospects: learning ability, foreign language ability, cooperation, information technology, and interpersonal relations. We also analyze the effect of differences in gender and family economic circumstances in relation to the 5 factors, and conclude that these influence
both students' employment prospects and their career planning.
The Role of Newswires in Screening and Disseminating Value-Relevant Information in Periodic SEC Reports
Authors: Li Edward Xuejun , Ramesh K. , Shen Min
Published: October 2010

ABSTRACT: We examine the role of newswires in identifying and conveying market-moving information in periodic SEC reports to capital market participants. Using data on Dow Jones Newswires, we find that newswires are more likely to send alerts on firms that do not release preliminary earnings, have credit ratings, are included in major market indices, have litigation exposure, or report losses. Reflective of the market’s focus on certain key events, firms with a nonstandard audit opinion, in the process of delisting, reporting unusual accounting items, or raising equity capital also receive alerts. Moreover, not only do we find significant price and volume reactions to the alerts at the daily level, but also we document immediate intra-day market activity triggered by the alerts, whereas we detect no similar reaction for SEC filings that trigger the alerts. Additional analysis suggests that the intra-day reaction is not driven by noise trading.
Persistent Increase of Prevalence of Metabolic Syndrome Among U.S. Adults: NHANES III to NHANES 1999–2006
Authors: Mozumdar Arupendra , Liguori Gary
Published: October 2010

OBJECTIVE

To compare the prevalence in metabolic syndrome (MetSyn) between 1988–1994 and 1999–2006 among U.S. adults of different races or ethnicities.

RESEARCH DESIGN AND METHODS

Analysis of data on 6,423 adult men and nonpregnant women aged ≥20 years from Third National Health and Nutrition Examination Survey (NHANES III) and 6,962 participants from the combined NHANES 1999–2006 were done. The revised National Cholesterol Education Program Adult Treatment Panel III definition was used to calculate MetSyn.

RESULTS

Both the unadjusted prevalence (27.9 ± 1.1% to 34.1 ± 0.8%, P < 0.001) and age-adjusted prevalence (29.2 ± 1.0% to 34.2 ± 0.7%, P < 0.001) increased from NHANES III to NHANES 1999–2006, respectively. Although MetSyn prevalence was highest in Mexican Americans, significant increases in prevalence occurred among non-Hispanic whites and non-Hispanic blacks, especially among younger women.

CONCLUSIONS

The persistent increase of MetSyn among U.S. adults is a serious public health concern because it raises the likelihood of increased prevalence of type 2 diabetes.
Genetic Risk Reclassification for Type 2 Diabetes by Age Below or Above 50 Years Using 40 Type 2 Diabetes Risk Single Nucleotide Polymorphisms
Authors: de Miguel-Yanes Jose M. , Shrader Peter , Pencina Michael J. , Fox Caroline S. , Manning Alisa K. , Grant Richard W. , Dupuis Josèe , Florez Jose C. , D'Agostino Ralph B. , Cupples L. Adrienne , Meigs James B. ,   the MAGIC Investigators,   the DIAGRAM+ Investigators
Published: October 2010

OBJECTIVE

To test if knowledge of type 2 diabetes genetic variants improves disease prediction.

RESEARCH DESIGN AND METHODS

We tested 40 single nucleotide polymorphisms (SNPs) associated with diabetes in 3,471 Framingham Offspring Study subjects followed over 34 years using pooled logistic regression models stratified by age (<50 years, diabetes cases = 144; or ≥50 years, diabetes cases = 302). Models included clinical risk factors and a 40-SNP weighted genetic risk score.

RESULTS

In people <50 years of age, the clinical risk factors model C-statistic was 0.908; the 40-SNP score increased it to 0.911 (P = 0.3; net reclassification improvement (NRI): 10.2%, P = 0.001). In people ≥50 years of age, the C-statistics without and with the score were 0.883 and 0.884 (P = 0.2; NRI: 0.4%). The risk per risk allele was higher in people <50 than ≥50 years of age (24 vs. 11%; P value for age interaction = 0.02).

CONCLUSIONS

Knowledge of common genetic variation appropriately reclassifies younger people for type 2 diabetes risk beyond clinical risk factors but not older people.
Frequent Monitoring of A1C During Pregnancy as a Treatment Tool to Guide Therapy
Authors: Jovanovič Lois , Savas Hatice , Mehta Manish , Trujillo Angelina , Pettitt David J.
Published: October 2010

OBJECTIVE

No guidelines for A1C measurement exist for women with gestational diabetes mellitus (GDM). The aim of this study was to document the rate of A1C decline in women with GDM.

RESEARCH DESIGN AND METHODS

Women with GDM in the Santa Barbara County Endocrine Clinic are managed with a carbohydrate-restricted diet and self-monitored blood glucose before and 1-h postprandial. Insulin is started if the preprandial glucose concentration is ≥90 mg/dl and/or a 1-h postprandial glucose concentration is ≥120 mg/dl. Capillary A1C was tested weekly using the DCA2000+ analyzer.

RESULTS

Twenty-four women with GDM (aged 29.0 ± 7.3 years) with initial A1C ≥7.0% were recruited. Baseline A1C was 8.8 ± 1.8%. Mean A1C decline was 0.47% per week (range 0.10–1.15%); the maximum was 4.3% in 4 weeks.

CONCLUSIONS

This study documents rapid decline in A1C during pregnancy and the utility of weekly A1C to guide therapy.
Google Earth as a Source of Ancillary Material in a History of Psychology Class
Authors: Stevison Blake K. , Biggs Patrick T. , Abramson Charles I.
Published: October 2010

This article discusses the use of Google Earth to visit significant geographical locations associated with events in the history of psychology. The process of opening files, viewing content, adding placemarks, and saving customized virtual tours on Google Earth are explained. Suggestions for incorporating Google Earth into a history of psychology course are also described.
Poems by a Suicide: Sara Teasdale
Authors: Lester David , McSwain Stephanie
Published: October 2010

An analysis of trends over time in the poems of Sara Teasdale as the time of her suicide approached identified a decrease in positive emotions and fewer references to the self and to others. These trends are different from those previously identified from studies of letters and diaries written by suicides.
Perceptions of a Tattooed College Instructor
Authors: Wiseman David B.
Published: October 2010

128 undergraduates' perceptions of tattoos on a model described as a college instructor were assessed. They viewed one of four photographs of a tattooed or nontattooed female model. Students rated her on nine teaching-related characteristics. Analyses indicated that the presence of tattoos was associated with some positive changes in ratings: students' motivation, being imaginative about assignments, and how likely students were to recommend her as an instructor.
A Reliability Analysis of the Revised Competitiveness Index
Authors: Harris Paul B. , Houston John M.
Published: October 2010

This study examined the reliability of the Revised Competitiveness Index by investigating the test-retest reliability, interitem reliability, and factor structure of the measure based on a sample of 280 undergraduates (200 women, 80 men) ranging in age from 18 to 28 years ( M = 20.1, SD = 2.1). The findings indicate that the Revised Competitiveness Index has high test-retest reliability, high interitem reliability, and a stable factor structure. The results support the assertion that the Revised Competitiveness Index assesses competitiveness as a stable trait rather than a dynamic state.
Religion in America—1972–2006: Religious Affiliation, Attendance, and Strength of Faith
Authors: Flannelly Kevin J. , Galek Kathleen , Kytle Jackson , Silton Nava R.
Published: October 2010

The present study used data from the General Social Survey, collected between 1972 and 2006 ( N = 45,463) to analyze changes over time in three aspects of religion among American adults: religious affiliation, frequency of attending religious services, and strength of faith. The last two measures were analyzed only for survey participants who had a religious affiliation. Ordinary least-squares regression confirmed a significant decrease in religious affiliation over time, after controlling for socio-demographic variables that are known to be associated with religion. A significant decrease in attending religious services was found among those survey participants who were religiously affiliated. As expected, participants who were African American, female, older, and from the South were more religious according to all three measures. No effect of birth-cohort was found for any religious measure. The results are discussed in the context of Stark and Bainbridge's 1996 theory of religion.
Publication Bias in Road Safety Evaluation: How can It be Detected and how Common is It?
Authors: Høye Alena , Elvik Rune
Published: October 2010

Publication bias denotes the tendency not to publish a study if its findings are not statistically significant or are regarded as unwanted or difficult to explain. In road safety evaluation research, studies that find an increase in the number of accidents as a result of a safety treatment may be less likely to be published than studies that find an accident reduction. How publication bias can be detected and how its influence on summary estimates of effect in meta-analyses can be determined are demonstrated by applying the trim-and-fill technique. Examples are based on recent analyses that indicate the presence of publication bias in studies that evaluate several different road safety measures. Although there is no way to determine conclusively how widespread publication bias is, indications of bias have been found for a number of well-known and widely applied road safety measures. Factors that may influence the likelihood of publication bias are discussed.
Accidents and Accessibility: Measuring Influences of Demographic and Land Use Variables in Honolulu, Hawaii
Authors: Kim Karl , Pant Pradip , Yamashita Eric
Published: October 2010

The current study examined the interplay between demographic, land use, and roadway accessibility variables and types of accidents in Honolulu, Hawaii. A uniform 0.1-mi2 grid was used as the basis for analysis and was combined with binomial logistic regression. Eight models were constructed to consider the relationship between total accidents, injury, fatality, pedestrian, bicycle, moped, motorcycle, and motor vehicle to motor vehicle crashes as a function of population, land use, and accessibility measures such as road length, bus stops, length of bus route, number of intersections, and dead ends. The results indicate that demographic variables such as job count and number of people living below the poverty level are significantly associated with injury crashes and pedestrian and bike crashes. Business and commercial areas are strongly associated with increased total as well as injury and fatal crashes. Accessibility measures such as the number of bus stops and the number of intersections are associated with increases in all types of accidents. The implications for safety research and other programs are summarized.
Personal Digital Assistants to Collect Data on Animal Carcass Removal from Roadways
Authors: Donaldson Bridget M. , Lafon Nelson W.
Published: October 2010

The increase in animal–vehicle collisions (AVCs) on U.S. roadways raises significant concerns for human safety, property damage and injury costs, and viability of wildlife populations. Valuable AVC data can be obtained from documentation of instances and locations of animal carcasses on the roadway, but most transportation organizations do not systematically record these data. In 2006, accidents reported by police in Virginia represented less than 14% of the 45,000 deer–vehicle collisions (DVCs) estimated from insurance industry claims. A project was carried out to test a personal digital assistant (PDA) enabled with a Global Positioning System (GPS) receiver for the collection and analyses of animal carcass removals from the roadway and to initiate the integration of this data collection method into regular practice by the Virginia Department of Transportation (VDOT). VDOT maintenance personnel collected 8 months of spatially accurate carcass removal data by using GPS-enabled PDAs. DVC estimates from this procedure were more than nine times greater than the number reported by police. Given the findings and efforts from the study, VDOT plans to integrate collection of carcass removal data with PDAs into regular practice. The procedures described in the report can guide other states interested in implementing a systematic and spatially accurate method for collecting AVC data. Implementing mitigation in high-density AVC areas can ultimately lead to fewer AVCs and associated reductions in human deaths, injuries, and financial losses; improved traffic operations; a reduction in maintenance costs related to carcass removal and disposal; and wildlife conservation.
Large-Scale Automated Analysis of Vehicle Interactions and Collisions
Authors: Saunier Nicolas , Sayed Tarek , Ismail Karim
Published: October 2010

Road collisions are a worldwide pandemic that can be addressed through the improvement of existing tools for safety analysis. A refined probabilistic framework is presented for the analysis of road-user interactions. In particular, the identification of potential collision points is used to estimate collision probabilities, and their spatial distribution can be visualized. A probabilistic time to collision is introduced, and interactions are grouped into four categories: head-on, rear-end, side, and parallel. The framework is applied to a large data set of video recordings collected in Kentucky that contains more than 300 severe interactions and collisions. The results demonstrate the usefulness of the approach for studying road-user behavior and mechanisms that may lead to collisions.
Effect of Street Pattern on Road Safety: Are Policy Recommendations Sensitive to Aggregations of Crashes by Severity?
Authors: Rifaat Shakil Mohammad , Tay Richard , de Barros Alex
Published: October 2010

In the past 50 years, the loops-and-lollipops design has become the basic building block of many urban neighborhoods. In the field of traffic engineering, this combination of cul-de-sacs and loop streets is designed to discourage through traffic and improve road safety, and thus it has the support of many traffic engineers. Perhaps because of its intuitive appeal, few studies have examined the impact of this design on road crashes. The city of Calgary, Alberta, Canada, was used as a case study to examine the effects of neighborhood street patterns on the number of reported crashes. In the study, crashes were converted into equivalent property-damage-only crashes using various weighting factors to check the sensitivity of the finding. Results suggest that currently popular road patterns such as warped parallel, loops, and lollipops are safer than the traditional gridiron pattern. Moreover, this result is quite robust regarding severity weights or aggregation schemes, albeit with some variations in the absolute values of the estimated effects. However, changing the aggregation scheme had a significant effect on some of the control variables used in the model, especially the socioeconomic characteristics, although most of the road features and land use estimates remained robust.
Near Crashes as Crash Surrogate for Naturalistic Driving Studies
Authors: Guo Feng , Klauer Sheila G. , Hankey Jonathan M. , Dingus Thomas A.
Published: October 2010

Naturalistic driving is an innovative method for investigating driver behavior and traffic safety. However, as the number of crashes observed in naturalistic driving studies is typically small, crash surrogates are needed. A study evaluated the use of near crashes as a surrogate measure for assessment of the safety impact of driver behaviors and other risk factors. Two metrics, the precision and bias of risk estimation, were used to assess whether near crashes could be combined with crashes. The principles and exact conditions for improved precision and unbiased estimation were proposed and applied to data from the 100-Car Naturalistic Driving Study. The analyses indicated that a positive relationship exists between the frequencies of contributing factors for crashes and for near crashes. The study also indicated that analyses based on combined crash and near-crash data consistently underestimate the risk of contributing factors compared to use of crash data alone. At the same time, the precision of the estimation will increase. This consistent pattern allows investigators to identify true high-risk behaviors while qualitatively assessing potential bias. In summary, the study concluded that the use of near crashes as a crash surrogate provides definite benefit when naturalistic studies are not large enough to generate sufficient numbers of crashes for statistical analysis.
Copula-Based Method for Addressing Endogeneity in Models of Severity of Traffic Crash Injuries: Application to Two-Vehicle Crashes
Authors: Rana Tejsingh A. , Sikder Sujan , Pinjari Abdul Rawoof
Published: October 2010

An emerging copula-based methodology is used to address endogeneity in models of crash injury severity. Specifically, two important sources of endogeneity are addressed: (a) endogeneity due to correlations between the injury severity of the two drivers involved in two-vehicle crashes and (b) endogeneity of collision type and injury severity outcomes. Two sets of copula-based joint model systems are formulated and estimated by using data on two-vehicle crashes from the 2007 Generalized Estimates System: a copula-based joint ordered logit–ordered logit model of injury severities of the two drivers involved in two-vehicle crashes and a copula-based joint multinomial logit–ordered logit model of collision type and injury severity outcomes of two-vehicle crashes. The model estimation results and elasticity estimates underscore the importance of accommodating endogeneity in models of crash injury severity. The results shed new light on the determinants of injury severity in two-vehicle accidents.
Predicting Single-Vehicle Fatal Crashes for Two-Lane Rural Highways in Southeastern United States
Authors: Zhu Hong , Dixon Karen K. , Washington Simon , Jared David M.
Published: October 2010

The rural two-lane highway in the southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes and as such remains a focus of considerable safety research. The Georgia Department of Transportation spearheaded a regional fatal crash analysis to identify various safety performances of two-lane rural highways and to offer guidance for identifying suitable countermeasures with which to mitigate fatal crashes. The fatal crash data used in this study were compiled from Alabama, Georgia, Mississippi, and South Carolina. The database, developed for an earlier study, included 557 randomly selected fatal crashes from 1997 or 1998 or both (this varied by state). Each participating state identified the candidate crashes and performed physical or video site visits to construct crash databases with enhance site-specific information. Motivated by the hypothesis that single- and multiple-vehicle crashes arise from fundamentally different circumstances, the research team applied binary logit models to predict the probability that a fatal crash is a single-vehicle run-off-road fatal crash given roadway design characteristics, roadside environment features, and traffic conditions proximal to the crash site. A wide variety of factors appears to influence or be associated with single-vehicle fatal crashes. In a model transferability assessment, the authors determined that lane width, horizontal curvature, and ambient lighting are the only three significant variables that are consistent for single-vehicle run-off-road crashes for all study locations.
Identifying Hot Spots by Modeling Single-Vehicle and Multivehicle Crashes Separately
Authors: Geedipally Srinivas Reddy , Lord Dominique
Published: October 2010

Considerable research has been conducted on the development of statistical models for predicting motor vehicle crashes on highway facilities. These models often have been used to estimate the number of crashes per unit of time for an entire highway segment or intersection without distinguishing the influence that subgroups have on crash risk. The two most important subgroups identified in the literature are single- and multi-vehicle crashes. Recently, researchers have noted that two distinct models for these two categories of crashes provide better predicting performance than models that combine both crash categories to predict crashes for an entire facility. Thus, a study was done to determine whether any difference exists in the identification of hot spots when a single model is applied instead of two distinct models. A hot spot (or black spot) is a site with an accident frequency that is significantly higher than expected at some prescribed level of significance. The data used for the comparison analysis were collected on Texas multilane undivided highways for 1997 to 2001. The study shows that modeling single- and multivehicle crashes separately predicts slightly fewer false positives and negatives than modeling them together under a single aggregated model in the hot spot identification process. Thus, it is recommended that separate models be developed for single- and multivehicle crashes for predicting crashes and for identifying hot spots.
Do Calculated Conflicts in Microsimulation Model Predict Number of Crashes?
Authors: Dijkstra Atze , Marchesini Paula , Bijleveld Frits , Kars Vincent , Drolenga Hans , van Maarseveen Martin
Published: October 2010

A microsimulation model and its calculations are described, and the results that are subsequently used to determine indicators for traffic safety are presented. The method demonstrates which changes occur at the level of traffic flow (number of vehicles per section of road) and at the vehicle level (vehicles choosing different routes). The best-known safety indicator in this type of model is the conflict situation, in which two vehicles approach each other and, if no action is taken, a crash will occur. These conflict situations are detected in the simulation model. This method does not necessarily relate directly to any actual observed conflicts or recorded crashes. The quantitative relationship is examined between detected conflicts at junctions in the model and recorded crashes at the same locations in the real world. The methods chosen for detecting conflicts and for selecting crashes are explained. A microsimulation model was constructed for a regional road network. The conflicts in this network were detected, and the recorded crashes were selected. The results show a quantitative relationship between the number of conflicts at priority junctions and the number of passing motor vehicles on one hand and the number of observed crashes on the other hand. When crashes and conflicts are divided into crash categories, junctions with signals clearly show substantial differences between the relative numbers of frontal crashes and frontal conflicts.
Use of Passenger Rail Infrastructure for Goods Movement
Authors: Sivakumaran K. , Lu X. Y. , Hanson M.
Published: October 2010

As demand for freight movement rises, so does truck traffic. In turn, traffic congestion, harmful emissions, maintenance costs, and accidents increase. One alternative to truck transport of goods is mixed-goods service on passenger rail networks, a concept that offers several benefits to the involved parties. These benefits include additional revenue for rail operators, more reliable travel times, reductions in harmful trucking externalities, and more efficient usage of existing facilities. As a case study, the use of the Bay Area Rapid Transit (BART) system in California for FedEx Express cargo movement is examined. FedEx Express was selected because the company's major hub is located at Oakland International Airport (OAK). To analyze the potential costs and benefits of BART mixed-goods service, two alternatives are compared against the status quo of truck-only transport. The first alternative assumes minor capital investment; the second assumes far greater capital investment, including a jointly operated BART–FedEx facility at OAK. Truck vehicle miles traveled (VMT), FedEx Express operating costs, BART operating costs, and carbon dioxide emissions are determined for the status quo and each alternative. Analysis shows that given sufficient demand, mixed-goods service can be profitable for passenger rail systems, cost-effective for air freight carriers, and highly effective in reducing truck VMT and associated externalities.
Development of Hazardous Materials Shipper Prioritization Application
Authors: Schaudt William A. , Bowman Darrell S. , Marinik Andrew , Hanowski Richard J. , Simmons James
Published: October 2010

In the mid-1990s, an attempt was made to develop a performance-based prioritization program to help the Federal Motor Carrier Safety Administration (FMCSA) during inspection and review of hazardous materials (HM) shippers. During this attempt, it became apparent that there were insufficient performance data to develop such a system (e.g., detailed information on incidents, violations, and shipments). In response, FMCSA developed the HM Package Inspection Program (HMPIP) to focus on inspecting individual shipments of HM at the roadside or on carriers' docks. In response to improvements made over the years to the package inspection data collected during HMPIP inspections, increased HM incident data, and improved departmental data identifying companies involved in shipping HM, FMCSA began a second effort to develop a performance-based HM shipper prioritization program. The Virginia Tech Transportation Institute was asked to review, document, and recommend improvements to the program. A thorough review and examination of the program was performed, and a prioritization software application was developed. Usability testing was performed in five states with existing shipper programs. All results were very good, indicating that the beta version of the program, with minor modifications based on user recommendations, should move forward into a fully functioning application for prioritizing HM shippers within FMCSA.
Resource use efficiency and community effects of invasive Hypochaeris radicata (Asteraceae) during primary succession
Authors: Schoenfelder Anna C. , Bishop John G. , Martinson Holly M. , Fagan William F.
Published: October 2010

• Premise of the study: We sought to better understand the impacts and mechanisms underpinning a successful invasion of resource‐poor sites by a nonnative plant on Mount St. Helens volcano (MSH).

• Methods: We investigated the short‐term effects of the nonnative plant Hypochaeris radicata on growth of native species colonizing drought‐prone primary successional surfaces under N‐limited and N‐augmented conditions. To understand the success of H. radicata, we compared its resource use efficiency to that of a closely related native colonist, Hieracium albiflorum, under the same conditions.

• Key results: Removing H. radicata did not affect growth of the most common colonists, but N addition demonstrated strong N limitation to growth in H. albiflorum, H. radicata, and Agrostis spp. Nonnative H. radicata exhibited lower water‐use efficiency than H. albiflorum but did not differ in efficiency of N use. H. radicata biomass increased faster in response to an N pulse than did the native H. albiflorum, as did the pool of N held in H. radicata tissues.

• Conclusions: Our findings contrast with results from Hawaiian volcanic sites, where higher short‐term resource use efficiency was reported for invasive species, including H. radicata. Our results suggest that at MSH, the success of H. radicata relies on rapid uptake and utilization of N rather than on higher efficiency. This strategy is especially advantageous at MSH because N pulses commonly occur as a consequence of herbivore‐induced mortality of Lupinus lepidus (Fabaceae).
Characterization of 14 microsatellite loci in a tropical palm, Attalea phalerata (Arecaceae)
Authors: Choo Juanita , Ishak Heather , Simpson Beryl , Mueller Ulrich , Juenger Tom
Published: October 2010

• Premise of the study: We developed microsatellite primers for the widely distributed tropical palm Attalea phalerata for studies on the dispersal and spatial genetic structure of palm populations.

• Methods and Results: Fourteen di‐, tri‐, and tetra‐nucleotide microsatellite primer pairs were identified. The number of alleles in the population tested ranged between 3 and 25, with a mean of 12.1. Ten microsatellite loci exhibited no significant deviations from Hardy–Weinberg Equilibrium or presence of null alleles, and their combined probability of exclusion was 0.998.

• Conclusions: These microsatellite loci will be useful in parentage analysis and population genetics studies of Attalea phalerata.
Disease Progression and Treatment Responses in a Prospective DMARD-naive Seropositive Early Rheumatoid Arthritis Cohort: Does Gender Matter?
Authors: JAWAHEER DAMINI , MARANIAN PAUL , PARK GRACE , LAHIFF MAUREEN , AMJADI SOGOL S. , PAULUS HAROLD E.
Published: October 2010

Objective.

To assess gender differences in disease characteristics and treatment responses over time in a disease-modifying antirheumatic drug (DMARD)-naive seropositive early rheumatoid arthritis (RA) cohort.

Methods.

Patients with polyarticular disease who were DMARD-naive and had seropositive early RA (< 14 months) were recruited by the Western Consortium of Practicing Rheumatologists. Each patient was examined at study entry, after 6 and 12 months, and yearly thereafter. Clinical and demographic data were collected. We investigated gender differences in baseline disease characteristics and treatment using chi-squared, Mann-Whitney U, and t tests. We used generalized estimating equations (GEE) models for repeated measures to examine whether the rate of change of specific disease outcomes during the first 2 years after DMARD initiation was significantly influenced by gender.

Results.

At baseline, men (n = 67) and women (n = 225) had similar disease activity and radiographic damage; men, however, had significantly worse erosion, while women had worse joint space narrowing. Despite similar treatment, women had worse disease progression over the 2-year followup, as assessed by trends in Disease Activity Score 28/erythrocyte sedimentation rate (DAS28-ESR4), physician global scores, and tender joint counts. In the GEE model, gender was significantly associated with the rate of change of DAS28-ESR4 scores (p = 0.009), although not independently associated with disease activity. Self-reported measures (Health Assessment Questionnaire-Disability Index, patient global scores, fatigue, pain) were worse among women at baseline and throughout the study period. Men were more likely to achieve remission.

Conclusion.

At baseline, men and women had similar disease activity and joint damage. Responses to treatment over time were better among men in this prebiologic era; women had worse progression despite similar treatment.
Arsenic Trioxide Induces Apoptosis of Fibroblast-like Synoviocytes and Represents Antiarthritis Effect in Experimental Model of Rheumatoid Arthritis
Authors: MEI YIFANG , ZHENG YINING , WANG HUI , GAO JUAN , LIU DIANXIN , ZHAO YANPING , ZHANG ZHIYI
Published: October 2010

Objective.

Recent studies have demonstrated that rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) proliferate as fiercely as tumor cells. Induction of apoptosis in RA FLS therefore provides a new approach for the inhibition of joint destruction. Arsenic trioxide (As2O3) was reported to be an effective apoptosis inducer in a variety of cell types. We investigated the possible effect of As2O3on apoptosis induction of RA FLS and the mechanisms involved in this process.

Methods.

Apoptosis was determined by flow cytometric analysis, terminal deoxynucleotide transferase-mediated dUTP nick end-labeling, and transmission electron microscopy. The activity and messenger RNA (mRNA) expression of nuclear factor-κB (NF-κB) was then detected by ELISA and real-time polymerase chain reaction, respectively. Activities of caspase-3 and caspase-8 were evaluated using luminogenic substrates. The effect of As2O3on the morphology of rats with collagen-induced arthritis was evaluated under a light microscope after H&E staining.

Results.

As2O3significantly enhanced the apoptosis of RA FLS. It suppressed the DNA-binding activity and mRNA expression level of NF-κB, probably by inhibiting tumor necrosis factor-α-induced activation of NF-κB. As2O3treatment significantly increased the activity of both caspase-3 and caspase-8. Morphological analysis revealed histological recovery in the synovial membrane. Synovial hyperplasia and inflammation in the joints were effectively inhibited.

Conclusion.

As2O3represents an apoptotic effect on RA FLS through NF-κB signaling pathway, and this process is mediated by the activation of caspase cascade. Treatment with As2O3significantly improved the pathologic changes of collagen-induced arthritis and may have potential for treatment of RA.
Increased Fracture Risk in Patients with Rheumatic Disorders and Other Inflammatory Diseases — A Case-Control Study with 53,108 Patients with Fracture: Table 1.
Authors: WEISS RÜDIGER J. , WICK MARIUS C. , ACKERMANN PAUL W. , MONTGOMERY SCOTT M.
Published: October 2010

Objective.

To identify the risk of hip and vertebral fractures in patients with rheumatic disorders (RD) and inflammatory bowel diseases (IBD).

Methods.

This population-based case-control study assessed the fracture risk of patients with rheumatoid arthritis, juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS), systemic lupus erythematosus, polymyositis/dermatomyositis (PM/DM), systemic sclerosis (SSc), Crohn’s disease, and ulcerative colitis (UC). The study cohort comprised 53,108 patients with fracture (66% women) and 370,602 age-matched and sex-matched controls. Conditional logistic regression analysis was performed and results were expressed as OR with corresponding 95% CI.

Results.

There was a statistically significant increased fracture risk for all RD and for IBD compared with controls. The magnitude of fracture risk was higher for patients with RD (OR 3, 95% CI 2.9–3.2) than for those with IBD (OR 1.6, 1.4–1.8). The OR in RD ranged from 2.6 (1.3–4.9) for SSc to 4 (3.4–4.6) for AS. The largest increased fracture risk for vertebral fractures was seen in AS (OR 7.1, 6–8.4) and for hip fractures in JIA (OR 4.1, 2.4–6.9).

Conclusion.

Our results highlight the existence of an increased fracture risk from a variety of underlying causes in patients with RD and IBD. In many inflammatory diseases, implementation of fracture prevention strategies may be beneficial.
Clinical Relevance of Nitric Oxide Metabolites and Nitrative Stress in Thrombotic Primary Antiphospholipid Syndrome
Authors: AMES PAUL R.J. , BATUCA JOANA R. , CIAMPA ANTONIO , IANNACCONE LUIGI , DELGADO ALVES JOSE
Published: October 2010

Objective.

To assess the role of nitrite (NO2−), nitrate (NO3−), and nitrative stress in thrombotic primary antiphospholipid syndrome (PAPS).

Methods.

We investigated 46 patients with PAPS: 21 asymptomatic but persistent carriers of antiphospholipid antibodies (PCaPL), 38 patients with inherited thrombophilia (IT), 33 patients with systemic lupus erythematosus (SLE), and 29 healthy controls (CTR). IgG anticardiolipin (aCL), IgG anti-beta2-glycoprotein I (anti-ß2-GPI), IgG anti-high density lipoprotein (aHDL), IgG anti-apolipoprotein A-I (aApoA-I), crude nitrotyrosine (NT) (an indicator of nitrative stress), and high sensitivity C-reactive protein (CRP) were measured by immunoassays. Plasma nitrite (NO2−), nitrate (NO3−), and total antioxidant capacity (TAC) were measured by colorimetric spectroscopic assays.

Results.

Average plasma NO2−was lower in PAPS, PCaPL, and IT (p < 0.0001); average NO3−was highest in SLE (p < 0.0001), whereas average NT was higher in PAPS and SLE (p = 0.01). In thrombotic PAPS, IgG aCL titer and number of vascular occlusions negatively predicted NO2−(p = 0.03 and p = 0.001, respectively), whereas arterial occlusions and smoking positively predicted NO3−(p = 0.05 and p = 0.005), and CRP positively predicted NT (p = 0.004). In the PCaPL group IgG aCL negatively predicted NO3−(p = 0.03). In the SLE group IgG aCL negatively predicted NO2−(p = 0.03) and NO3−(p = 0.02).

Conclusion.

PAPS is characterized by decreased NO2−in relation to type and number of vascular occlusions and to aPL titers. Nitrative stress and low grade inflammation are linked phenomena in PAPS and may have implications for thrombosis and atherosclerosis.
Effect of a Symptom Diary on Symptom Frequency and Intensity in Healthy Subjects
Authors: FERRARI ROBERT , RUSSELL ANTHONY SCIENCE
Published: October 2010

Objective.

Symptom and pain diaries are often recommended to or used by patients with chronic pain disorders. Our objective was to examine the effect on recall of symptoms after 14 days of daily symptom diary use in healthy subjects.

Method.

Subjects were randomly assigned to 1 of 2 groups: the diary group and the control group. Both subject groups completed an initial symptom checklist composed of headache, neck pain, back pain, fatigue, abdominal pain, elbow pain, jaw pain, and numbness/tingling in arms or legs. Both groups indicated their symptom frequency and their perceived average symptom severity in the last 14 days. The diary group was asked then to examine the symptom checklist daily for 14 days while the control group was not. After 2 weeks, both groups then repeated the symptom checklist for recall of symptoms and symptom severity.

Results.

A total 35 of 40 initially recruited subjects completed all the questionnaires, 18 in the diary group and 17 in the control group. At the outset, both groups had similar frequencies and intensities of symptoms. After 2 weeks of symptom diary use, diary group subjects had an increased frequency (doubled) of recalled symptoms, and significantly increased intensity of symptoms compared with the control group, which had not changed its mean frequency or intensity of symptoms.

Conclusion.

The use of a symptom diary for 2 weeks, even in generally healthy subjects, results in increased recall of daily symptoms and increased perception of symptom severity.