bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety Effects of Using Short Left-Turn Lanes at Unsignalized Median Openings
Authors: Chen Xiaoming , Qi Yi , Lu Yan
Published: January 2015

The AASHTO Green Book specifically encourages the use of left-turn lanes at median openings on divided roadways to eliminate stopping in through-traffic lanes. However, the lengths for median left-turn lanes recommended by the Green Book are often impractical in urban areas, where the available distance between two adjacent openings is inadequate, and particularly where the volume of left-turning traffic is heavy. Thus, left-turn lanes shorter than the lengths recommended by the Green Book (referred to as short left-turn lanes) are in wide use on urban divided roadways. The objective of this study was to investigate the safety performance of short left-turn lanes at unsignalized median openings. To this end, 6 years of crash data were collected in Houston, Texas, from 52 median left-turn lanes (40 short lanes and 12 lanes with lengths in compliance with Green Book recommendations). A Poisson regression model was developed to relate traffic and geometric attributes to the total number of rear-end, sideswipe, and object–motor vehicle crashes in a left-turn lane. Crash modification factors were calculated for applications to project the crash frequency for a specific change in lane length. Statistical evidence indicates that the difference between actual lane length and Green Book–recommended length has significant effects on crash frequency. However, the increase in crash frequency as a result of short left-turn lanes might be acceptable in cases where engineers must account for traffic and economic and social effects in determining whether a short left-turn lane is appropriate.
Model of Flow Regimes in Porous Pavement and Porous Friction Courses
Authors: Ranieri Vittorio , Colonna Pasquale , Ying Gaoxiang , Sansalone John
Published: January 2015

Porous pavements (PPs) and porous friction courses (PFCs) are increasingly recognized as viable alternatives to traditional impervious pavements. PPs and PFCs passively provide safety, hydrologic, and rainfall-runoff treatment benefits. These benefits are a result of such permeable systems providing hydraulic conveyance and filtration of particulate matter (PM) transported by runoff. With respect to hydrology, these systems reintroduce infiltration, evaporation, and storage phenomena; with respect to traffic and road safety, the systems increase skid resistance in wet conditions, reduce hydroplaning, and reduce splash-and-spray phenomena; with respect to runoff treatment, the systems function as a filter for PM and PM-bound constituents. These phenomena and the models therefore are a function of the hydrodynamics (which are not necessarily laminar) in the porous medium and commonly are characterized by the hydraulic conductivity of the porous medium. The measured hydraulic conductivity (permeability) was examined in 12 common porous asphalt mixes. A Darcian model for hydraulic conductivity in the laminar flow regime was examined, as commonly done for PPs and PFCs. However, hydrodynamic regimes in porous asphalt that extended beyond laminar flow during testing were identified for these porous mixes. Therefore, the variability of the hydraulic conductivity as a function of applied hydraulic head in a hydrodynamic regime (based on the Reynolds number) was measured and modeled. From these results, a saturated seepage model was developed; it is valid for laminar and transitional regimes. Implications for the application of standardized permeameter testing of such porous mix designs are reported.
Using Third-Party Data for Travel Demand Modeling
Authors: Kressner Josephine D. , Garrow Laurie A.
Published: January 2015

This research investigated how targeted marketing (TM) data could be used as a source for up-to-date demographic and socioeconomic information. TM data provide several advantages over data from the Bureau of the Census, including the ability to incorporate additional behavioral information through lifestyle variables and to conduct longitudinal studies at a low cost. This paper describes TM data and a comparison of an Atlanta, Georgia, sample with census data. The most recent household travel survey conducted by the Atlanta Regional Commission was compared with census data; both weighted and unweighted survey data were used. Results showed that the distributions of socio-demographic variables were similar, particularly for age, gender, household income, and the presence of children. The largest discrepancies between TM data and census data were associated with educational attainment and ethnicity; however, these discrepancies were comparable to those observed in the household travel survey.
Calibration of Rail Transit Assignment Model with Automated Fare Collection Data and a Parallel Genetic Algorithm
Authors: Zhu Wei , Xu Ruihua , Jiang Yue-Ping
Published: January 2015

In recent years, cities around the world have begun to use automated fare collection (AFC) systems with smart card technologies as the main method of collecting urban rail transit (URT) fares. Transaction data obtained through these AFC systems contain a large amount of archived information about how passengers use the URT system. These data can be used to calibrate assignment models for precise passenger flow calculations. However, this calibration typically is a computationally intensive problem because of multiroute searches, iteration strategies, and especially massive AFC data sets. This paper proposes a methodology for calibrating URT assignment models with AFC data and a parallel genetic algorithm. The calibration approach uses a framework based on a parallel genetic algorithm with nonparametric statistical techniques, which calibrate assignment model parameters by comparing observed and calculated travel time distributions. In initial case studies on the URT network in Beijing, the proposed approach found reasonable solutions for the calibrated parameters.
Arriving Next on Track 1
Authors: Makler Jon , Harvey Morgan , Callas Steve , Tufte Kristin , Peterson Ryan
Published: January 2015

This paper describes a successful initiative in Portland, Oregon, to develop a web-based archive for geospatial transit performance data. The transit industry collects vast quantities of performance data. Archived data user services have evolved, but there is an absence of comparable (online, public, interactive) data archives for transit. In response to a request from the Tri-County Metropolitan Transit District of Oregon, which sought help with spatial visualization of its performance data, a team at Portland State University used a combination of open- and closed-source software to create a network layer on which stop- and segment-based performance measures could be displayed. The team then created a web-based application that allows individual users to run custom queries as well as to run other functions. The primary outcome was an increased understanding of transit operations that better informs high-level decision making. The secondary outcome was a multimodal data archive that benefits the research community. Future work will focus on upgrading the flow of data from quarterly to real time, which will require considerable work in the management of data quality. The methods by which the team visualized agency performance data and provided web-based access are replicable by other transit properties, particularly those with general transit feed specification data.
Highway versus Urban Roads
Authors: Yazici M. Anil , Kamga Camille , Ozbay Kaan
Published: January 2015

In this study, the differences in travel time variability patterns between urban roads and highways were analyzed. For urban roads, a GPS data set that included all taxi trips in New York City was used. For highways, automatic vehicle location data from the New Jersey Turnpike were used. The turnpike was divided into two sections, urban and suburban highway, according to urbanization level, time-of-day demands, and physical roadway features. The analysis not only compared travel time patterns for highways and urban roads but also investigated travel time characteristics along the same highway facility. First, the temporal variations of travel times on both facility types were calculated and compared. Second, the travel time distributions were extracted for various time periods and compared visually to determine the distributional patterns. Finally, the relationship between the average travel time and variability was investigated. Not only did travel time patterns differ between urban roads and highways, but major differences in travel time characteristics could be observed along the same highway. Higher travel times corresponded to lower reliability on highways yet corresponded to higher reliability on urban roads. Overall, the findings suggest that attributing differences in travel time variability patterns to facility type may be an oversimplification of the phenomenon.
Application of Finite Mixture of Regression Model with Varying Mixing Probabilities to Estimation of Urban Arterial Travel Times
Authors: Chen Peng , Yin Kai , Sun Jian
Published: January 2015

Travel time along an urban arterial is greatly affected by traffic signals. Most studies on urban travel time use statistical models to obtain the distribution directly without incorporating the effects of traffic signal timing. In this study, a finite mixture of regression model with varying mixing probabilities (weights) was proposed to gain a better understanding of urban travel time distribution through consideration of signal timing. Standard finite mixture models with constant mixing probabilities have a limited ability to adapt to underlying random structural changes for observed travel times. The model developed in this study can capture such dynamics by ( a) modeling the mixing probabilities as a function of the explanatory variables associated with signal timing and ( b) establishing a linear regression between the mean of each component and signal timing. The finite mixture of regression model was applied to the travel time data collected by the automatic vehicle identification system on one urban arterial with the Sydney coordinated adaptive traffic system (SCATS). The results demonstrate that the varying mixing probabilities can be used to classify the samples of travel time, and the mean values of components can capture the effects of signal timing. By comparing various types of mixture models, the proposed approach not only has a better statistical fitting performance but also provides useful information about travel time features.
Real-Time Prediction of Arterial Roadway Travel Times Using Data Collected by Bluetooth Detectors
Authors: Moghaddam Soroush Salek , Hellinga Bruce
Published: January 2015

Bluetooth detectors are gaining in popularity as a cost-effective technology for acquiring travel time data. The sensors, which identify and record the unique media access control address of Bluetooth-enabled devices, can measure travel time when a device passes through the detection zone of two consecutive Bluetooth detectors. As with other automatic vehicle identification technologies (e.g., toll tags, automatic license plate recognition systems), there is a time lag because the travel time cannot be acquired until the vehicle has passed the downstream detector location. The increasing desire for accurate and timely traveler information and the desire for proactive traffic control present a need for accurate prediction of near-future travel times along roadway corridors. A significant body of literature has focused on this problem for freeways, but little effort has been directed toward signalized arterials. This paper presents a data-driven model for predicting near-future travel times on signalized arterials in real time by using data acquired from Bluetooth detectors. The model uses the k nearest neighbor pattern recognition technique to identify historical data from which an understanding of the near-future traffic patterns can be extracted. Unlike previous efforts, an objective approach was used to determine the variables to include in the k nearest neighbor feature vector and the optimal model parameters. The calibrated model was evaluated through application to a set of field data obtained from Bluetooth detectors deployed on a signalized arterial. The model provides performance improvements of approximately 20% over a benchmark model.
Algorithm for Detecting Outliers in Bluetooth Data in Real Time
Authors: Moghaddam Soroush Salek , Hellinga Bruce
Published: January 2015

Bluetooth detectors are becoming increasingly popular as a technology for acquiring travel time data. However, these data include outliers that are caused by several factors, and a robust outlier detection algorithm is needed for filtering out the outliers. Arterial roadways present a particularly challenging environment because the traffic control devices introduce a large amount of variability to the measured individual travel times and because of the prevalence of other sources of error (e.g., en route stops, Bluetooth-enabled devices not in vehicles). This paper presents a new adaptive outlier detection algorithm that is proactive rather than reactive. Unlike conventional reactive algorithms that rely solely on recent data, the proposed algorithm uses both historical data and current data to predict the validity window. The performance characteristics of the proposed algorithm are illustrated, and field data from a signalized arterial are used to compare the proposed algorithm and a benchmark algorithm. The results show that the proposed model is superior to the benchmark model and that the model performs well across a wide range of traffic conditions.
Link and Route Travel Time Prediction Including the Corresponding Reliability in an Urban Network Based on Taxi Floating Car Data
Authors: Tulic Mirsad , Bauer Dietmar , Scherrer Wolfgang
Published: January 2015

This study addressed the modeling of route travel times (including their associated uncertainty) in urban networks based on taxi floating car data. The model decomposes observed link travel speeds into the expected speed (modeled with daily and seasonal profiles) and deviations thereof. The latter were shown to be strongly heteroscedastic by providing an explicit model for the time variance. Temporal and spatial correlations were considered with a vector autoregression framework. Modeling was supported by automatic model selection methods for identifying the relevant effects and providing one-step-ahead predictions. The potential of the proposed model was investigated with taxi floating car data from a real-world test site near the city core of Vienna, Austria. Various specifications of the vector autoregression model were tested and compared. Taxi floating car measurements of local speeds were found to be strongly heteroscedastic, a factor that must be considered in estimation of models for expected travel speeds. The modeling of the mean suggested no remaining daily or weekly patterns, and it was superior to simple models explaining travel speeds as a linear function of the travel speeds in the last time period. The variance model successfully captured heteroscedasticity. More complex models for link travel speeds, including temporal and spatial correlation, do not increase prediction accuracy consistently; the lack indicates that a sampling frequency of 15 min for floating car data in urban settings is too low for use of temporal dependencies for prediction. An introduced method for computing route travel time uncertainty showed variability over the day for a highly frequented route.
Vacuum Sealing–Based Volumetric Density Measurement Approach for Cold In-Place Recycling
Authors: Cox Ben C. , Howard Isaac L.
Published: January 2015

Recent economic limitations have fostered increased use of pavement rehabilitation methods such as cold in-place recycling (CIR). CIR could be more appealing to departments of transportation provided variability were lower and performance were more predictable. Because of the nature of the materials and construction processes, CIR is likely to be more variable than plant-mixed asphalt, and it is believed that the performance variability of CIR can be reduced through enhanced density control. The many density control methods described in the literature for CIR are often vague. This study used ASTM D6857 vacuum sealing to obtain the maximum theoretical specific gravity ( Gmm) of reclaimed asphalt pavement (RAP) and a gravity-proportioning equation to estimate CIR Gmm (specific gravity after cement, emulsion, or a combination is mixed with RAP). Vacuum sealing was also used to obtain the bulk specific gravity ( Gmb) of compacted CIR (AASHTO T 331). In all, 240 Gmm and 156 Gmb tests were conducted. D6857 and AASHTO T 209 detect differences between RAP and hot-mix asphalt Gmm, but the differences led to manageable errors for CIR density control that should still allow for some improvements over many current practices. The equation developed in the study estimated CIR Gmm with reasonable error, and T 331 suitably characterized CIR Gmb at the often high air void levels that were observed. The findings show that CIR Gmm and Gmb, as determined by vacuum sealing and the gravity-proportioning equation, constitute a reliable, convenient, and implementable approach to controlling density and likely reducing performance variability.
Impact of Freeze–Thaw Cycles on Mechanical Properties of Asphalt Mixes
Authors: El-Hakim Mohab , Tighe Susan L.
Published: January 2015

This study presented a statistical assessment of the impact of freeze–thaw cycles on deterioration of the mechanistic properties of asphalt mixes. The experimental matrix included several samples of asphalt mixes that were tested with dynamic modulus. The specimens were retested after being subjected to freeze–thaw cycles to simulate the impacts of the Canadian climate on asphalt mixes. The Ministry of Transportation of Ontario constructed a test section in partnership with the University of Waterloo, the Ontario Hot Mix Producers Association, the Natural Sciences and Engineering Research Council of Canada, and other partners to evaluate the use of perpetual flexible pavement design in southern Ontario, Canada. The test section was constructed on Highway 401, and samples from several asphalt mixes used in construction were structurally evaluated through dynamic modulus testing shortly after construction. The samples were then subjected to freeze–thaw cycles and retested to evaluate the environmental impact on dynamic modulus (| E*|) as a representative of pavement structural deterioration. The dynamic modulus results were used to evaluate the benefits obtained by adding 0.8% of additional binder to the regular Superpave® (SP) 25 mix to develop an SP 25 rich bottom mix (RBM). The dynamic modulus results did not show a statistically significant difference between the average | E*| of the SP 25 and SP 25 RBM after construction. However, the benefits of additional binder content showed up clearly after freeze–thaw cycles simulating 1 year in service. Overall, the study provided guidance on perpetual pavement design and the various asphalt layer performances within the design.
High-Temperature Characterization of Highly Modified Asphalt Binders and Mixtures
Authors: Mohseni Alaeddin , Azari Haleh
Published: January 2015

To characterize highly modified asphalt binders under high temperatures, this paper presents an alternative that uses the incremental repeated load permanent deformation (iRLPD) test in lieu of the multiple stress creep recovery (MSCR) test. The rationale for the iRLPD test includes a reduced loading time that better correlates with field-loading conditions, decreased variability of results, and an improved estimation of highly modified binder behavior. Moreover, an iRLPD high-temperature model for the highly modified binder is presented; this model is also correlated to the iRLPD traffic model to provide traffic estimates through the use of the iRLPD mixture parameter. Laboratory results indicate that as the level of binder modification increases, MSCR underestimates the strain response that can lead to overestimation of traffic levels. The study also illustrates the effect of the stress–strain nonlinearity parameter, which increases as the level of binder modification increases. The difference in the permanent strain and recovery response from the two methods is exacerbated by the level of binder modification; however, for neat binders, the MSCR and iRLPD strain ratio approaches unity. The results demonstrate that the permanent strain of polymer modified binder is highly time dependent and thus the loading time for testing asphalt binders should be properly selected. The LTPPBind software seems to underestimate the traffic levels calculated from the iRLPD and MSCR models; nevertheless, the results of iRLPD and LTPPBind are in agreement, insinuating that the LTPPBind model underpredicts the traffic level for neat binders, whereas the MSCR model overpredicts the traffic level for highly modified binders.
Turning Back Time
Authors: Nahar S. N. , Qiu J. , Schmets A. J. M. , Schlangen E. , Shirazi M. , van de Ven M. F. C. , Schitter G. , Scarpas A.
Published: January 2015

Countermeasures to the aging of bituminous asphalt binders is a highly important topic for service-life extension of asphalt in the field and for recycling old pavements into new structures with similar functional requirements as the original structure. Countermeasures are usually achieved by applying additives that restore the adhesive and mechanical properties of the original bituminous binder. The additives are commonly termed (asphalt) rejuvenators. This study examined the performance of two very distinct rejuvenating agents. The effectiveness of rejuvenators is usually measured by comparing the penetration and softening point of the rejuvenator-aged bitumen blend with reference values of the virgin binder. The study used a dynamic shear rheometer to evaluate the rejuvenating capabilities of the two additives. The microstructures of the virgin binder and the rejuvenated blends were obtained by atomic force microscopy. Subsequently, the rheological results were related to the microstructure morphologies. From the rheological experiments, both rejuvenators exhibited the desired softening and property-restoring performance. However, there was a strong difference in the amount of rejuvenator needed to achieve complete rejuvenation. By correlating rheology to the microstructural observations, the effects of the rejuvenators were found to be distinct at microscopic length scales: rejuvenation was achieved by distinct chemophysical mechanisms. One of the rejuvenators restored the virgin microstructure, whereas the other rejuvenator generated a new morphology. Thus, the study demonstrated that by combining rheological and microstructural techniques, the mechanism and performance of rejuvenation can be understood. This finding may help guide future designs and optimization of asphalt-rejuvenating agents.
Characteristics of Virgin and Recycled Asphalt Shingle Binder Blends
Authors: Zhou Fujie , Chen Peiru , Huang Shin-Che
Published: January 2015

Application of recycled asphalt shingles (RAS) into hot-mix asphalt have been well accepted by many transportation agencies in recent years. However, limited information on virgin-RAS binder blends is available. This study focused on the rheological and chemical characteristics of different blends. Two virgin binders (PG 64-22A and PG 64-22B) and three RAS binders (original RAS binder, extracted RAS binders from tear-off, and manufacture waste asphalt shingles) were used. Different from the well-known linear blending of virgin and reclaimed asphalt pavement binders, the virgin and RAS binder blending followed a nonlinear trend. The nonlinear behavior was found to relate closely to the asphaltene content of the virgin and RAS blends. Furthermore, the identified nonlinear behavior could be described by a simple linear equation because the normalized increase in high-temperature performance grade varied linearly with the increase in the RAS binder content. The Christensen–Anderson (CA) model and the Williams–Landel–Ferry (WLF) shifting equation successfully described the complex shear modulus behavior of different blends of virgin and RAS binders. The results also showed that adding RAS binders to virgin binders had a similar impact as that of aging on rheological parameters such as the rheological index, crossover frequency, and WLF parameters. The addition of RAS binder reduced the temperature susceptibility of virgin binders. In addition, the study found that the carbonyl area measured with a Fourier transform infrared-attenuated total reflectance spectroscopy was highly related to the CA model and the WLF shifting parameters.
Quantification of Water in Asphalt by Karl Fischer Titration and Its Application to Emulsion Recovery
Authors: Boysen Ryan B. , Farrar Michael J. , Planche Jean-Pascal
Published: January 2015

In this study, the Karl Fischer (KF) titration method for quantification of water was successfully applied to asphalt binder. Previously, observed side reactions between the titration solvent and certain functional groups present in asphalt prevented accurate KF-type titration. However, recent advances in KF solvent formulation have allowed for rapid titration of water in asphalt with minimal interference reactions. Repeatable results were obtained with moisture-sensitive techniques such as drying glassware, using only anhydrous solvents, and performing all sample preparation in a dry atmosphere. The developed KF titration method was implemented in the evaluation of three competing laboratory asphalt emulsion residue recovery procedures. All three methods showed sufficient removal of water for rheologic testing of the eight recovered residues. Measuring the water content in recovered residues by the mass lost at 135°C was not suitable for some emulsion residues because of the evaporation of nonwater solvent or distillate at the elevated temperature.
Evaluating Aging Properties of Crumb Rubber and Styrene–Butadiene–Styrene Modified Binders
Authors: Naderi Koorosh , Asgharzadeh Seyed Mohammad , Tabatabaee Nader , Partl Manfred N.
Published: January 2015

In recent years, one of the questions about modified binders has been the durability of their improved performance throughout their service life. Aging properties of modified binders in various frequency and temperature ranges depend on the class and concentration of the modifiers as well as the binder type. The aging characteristics have been evaluated in several ways, but the use of master curve models for modified binders has received little attention because of the lack of appropriate models with an easily manageable number of parameters. A recently developed mathematical model, Double Logistic (DL), can be used to characterize the master curves of modified binders. For the investigation of the rheological properties of aged and unaged modified binders, two modifiers, styrene–butadiene–styrene and ground tire rubber, were selected. Two binder types were selected to evaluate the binder dependency of the results. All modified binders were subjected to short- and long-term aging conditions in the laboratory. Then the rheological master curves of the complex modulus and phase angle of all the binders in various aging conditions were generated and fitted by the DL model. The model correctly predicted the phase angle plateau values and other irregularities for many polymer-modified binders in several aging conditions in this research. In addition, the DL model captured aging behaviors, such as hardening or softening, more elastic or viscous response, and lower or higher temperature susceptibility of the neat and polymer modified binders at various temperature and frequency ranges.
Sensitivity of Nozzle-Based Foamed Asphalt Binder Characteristics to Foaming Parameters
Authors: Ozturk Hande I. , Kutay M. Emin
Published: January 2015

Foam-based warm-mix asphalt technologies decrease the overall viscosity of the asphalt mixture at lower temperatures so that it is workable during construction. However, after construction, viscosity increases rapidly as the foam disappears and the temperature drops. Although the production of the foamed binder is a relatively simple process, in which hot binder is mixed with a limited amount of water (typically 1% to 3% by weight of the binder), the rheology of the foamed binder is complex. The characteristics of foamed binders depend on various factors such as the binder type, grade, and modification; the foaming technology used; amount of water; and temperature. This study investigated the sensitivity of the characteristics of foamed binders to parameters such as injected air pressure and water content. The foamed binder characteristics, including the expansion ratio, half-life, foam index, bubble size distribution, and surface area index, were measured with a novel automated laboratory device called the asphalt foam collapse test. The measurements were conducted in several conditions, including ( a) constant water content and variable air pressure, ( b) variable water content and constant air pressure, and ( c) variable air pressure and water content. It was concluded that both water content and air pressure significantly affected foamed binder characteristics and their internal morphology.
Thermal Properties of Thermochromic Asphalt Binders by Modulated Differential Scanning Calorimetry
Authors: Hu Jianying , Wanasekara Nandula , Yu Xiong (Bill)
Published: January 2015

Thermochromic materials are substances that can reversibly change their colors in response to temperature. These materials can be designed to have high solar reflectance at high temperature and low solar reflectance at low temperature. They are therefore potential new smart materials that can improve pavement thermal conditions. The innovation of this study was to develop thermochromic asphalt binders possessing dynamic solar reflectance in response to environmental temperature. The preliminary study indicated that the thermochromic binder coating achieved a temperature reduction as high as 6.4°C under the conditions of a typical summer day in Cleveland, Ohio. A comparison of measurements under cold conditions in Cleveland demonstrated that thermochromic asphalt binder could remain warmer than conventional asphalt binder. This attribute helps to improve the resistance of asphalt pavement to low- temperature cracking, delays ice formation on the road surface, and potentially improves the durability and safety of asphalt roads. The phase transition temperature and latent heat of thermochromic asphalt binders were characterized by standard differential scanning calorimetry (DSC). The specific heat capacity, thermal conductivity, and thermal diffusivity of thermochromic asphalt binders were determined by modulated DSC at temperatures ranging from –20°C to 50°C. Comparison measurements found that thermochromic asphalt binders presented higher specific heat capacity, lower thermal conductivity, and lower thermal diffusivity than conventional pure asphalt binders. Empirical models were proposed for the variations of specific heat capacity and thermal conductivity of various asphalt binders as a function of temperature. These models provided data for design and simulation of thermal responses of asphalt pavement incorporating thermochromic binder materials.
Palladium-loaded Renewable Polymer as a Green Heterogeneous Catalyst for Cross-coupling Reactions under Microwave Irradiation
Authors: Pan Dan , Wu Aiqun , Li Pengfei , Xu Haitang , Lei Fuhou , Shen Liqun
Published: January 2015

A new palladium catalyst was prepared by immobilising ligand 2, 2′-dipyridylamine on the backbone of an acidic rosin polymer from gum rosin, on to which palladium(II) was bound via coordination. The catalyst at a low loading of 0.2 mol% was found to be highly effective for Suzuki–Miyaura coupling reactions of aryl halides and arylboronic acids under microwave irradiation in the presence of 1 equiv. of Na2CO3, affording excellent yields of the corresponding biaryls. Moreover, the catalyst exhibited very good recyclability over three cycles.
Synthesis of 2-amino-4-(methoxycarbonyl)Phenylboronic Acid Hydrochloride, a key Intermediate for the Synthesis of Quinolines Derivatives
Authors: Xue Feng , Li Chang-Gong , Zhu Yong , Lou Tian-Jun
Published: January 2015

A practical and efficient process for the synthesis in good yield of 2-amino-4-(methoxycarbonyl)phenylboronic acid hydrochloride from p-bromo toluene has been developed via borylation, oxidation, nitration, esterification and hydrogenation.
Naphthalenones and Isocoumarins from a Costa Rican Fungus Xylariaceae sp. CR1546C
Authors: Kim Ki Hyun , Beemelmanns Christine , Murillo Catalina , Guillén Anny , Umaña Loengrin , Tamayo-Castillo Giselle , Kim Su-Nam , Clardy Jon , Cao Shugeng
Published: January 2015

A new naphthalenone, ( R)-4,6,8-trihydroxy-3,4-dihydro-1(2 H)-naphthalenone and a new isocoumarin, 6,8-dihydroxy-(3 R)-(2-oxopropyl)-3,4-dihydroisocoumarin, together with eight related known compounds were isolated from the endolichenic fungal species, CR1546C from Costa Rican lichen Sticta fuliginosa (Lobariaceae). Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques and chemical methods. All of the isolated compounds exhibited moderate antifungal activity against the yeast Candida albicans.
N-bromosuccinimide/cerium Ammonium Nitrate: An Efficient Reagent for Stereo-controlled Deamination of Ketoaziridines
Authors: Samimi Heshmat Allah , Salehi Elham , Dadvar Farkhondeh
Published: January 2015

An efficient and novel method for the deamination of trans-1-alkyl (H or benzoyl)-2-aroyl aziridines in a completely stereo-controlled reaction in the presence of N-bromosuccinimide/cerium (IV) ammonium nitrate is described. In comparison with the previous reported work, this reaction reveals a substituent-reactivity relationship and important role for the substituent on C1 and C2 in determining whether deamination or oxidation reaction takes place.
Chemistry of Phosphorus Ylides: Part 41 Synthesis of Antimicrobial Agents from the Reaction of Aminoantipyrine, Coumarin- and Quinoline-carbaldehyde with Phosphacumulene and Phosphaallene Ylides
Authors: Maigali Soher Said , Abd-El-Maksoud Mansoura Ali , El-Hussieny Marwa , Soliman Fouad Mohamed , Abdel-Aziz Mohamed Soliman , Shalaby El-Sayed Mohamed
Published: January 2015

Pyrrolo-pyrazoles were obtained from the reaction between phosphacumulenes and aminoantipyrine, while the reaction with the phosphaallene (hexaphenylcarbodiphosphorane ylide) afforded the azaphosphole and pyrazolo-phosphanylidene. The aminocoumarin carbaldehyde gave the chromeno-phosphanylidene and the chromeno-pyridinone, when it was allowed to react with phosphacumulenes. The reaction of chloroquinoline carbaldehyde with the phosphacumulenes, gave chloroquinoline phosphanylidenecyclobutane, while the reaction with phosphaallene resulted in the formation of oxaphosphetane, phosphanylidene ethenyl- and oxaphosphetyl-quinoline. The structure of cyclobutanedione was confirmed by X-ray crystallography. The antimicrobial activity of the new compounds is also reported.
Oxidative Coupling Reaction of 1,3-diarylpropenes with Propane-1,3-dione Derivatives Mediated by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with Molecular Oxygen
Authors: Cheng Dongping , Yuan Kun , Zhou Xiayi , Yan Jizhong
Published: January 2015

An oxidative coupling reaction between 1,3-diarylpropenes and propane-1,3-dione derivatives mediated by a catalytic amount of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and azobisisobutyronitrile with molecular oxygen has been developed. The corresponding products are obtained in moderate to good yields.
Synthesis of Pyrrolo[2,3-b]pyrazines Through Sonogashira Coupling Reaction of 5,6-dichloropyrazine-2,3-dicarbonitrile with Hydrazine, Phenylacetylene and Various Aldehydes
Authors: Bakherad Mohammad , Keivanloo Ali , Omidian Mina , Samangooei Shahrzad
Published: January 2015

The Pd–Cu catalysed one-pot multicomponent reaction of 5,6-dichloropyrazine-2,3-dicarbonitrile with hydrazine, phenylacetylene, and a variety of aldehydes provides an efficient and direct method for the preparation of 5-(arylideneamino)-6-phenyl-5H-pyrrolo[2,3- b]pyrazine-2,3-dicarbonitriles.
Temporal Expression of Growth Factors Triggered by Epiregulin Regulates Inflammation Development
Authors: Harada Masaya , Kamimura Daisuke , Arima Yasunobu , Kohsaka Hitoshi , Nakatsuji Yuji , Nishida Makoto , Atsumi Toru , Meng Jie , Bando Hidenori , Singh Rajeev , Sabharwal Lavannya , Jiang Jing-Jing , Kumai Noriko , Miyasaka Nobuyuki , Sakoda Saburo , Yamauchi-Takihara Keiko , Ogura Hideki , Hirano Toshio , Murakami Masaaki
Published: January 2015

In this study, we investigated the relationship between several growth factors and inflammation development. Serum concentrations of epiregulin, amphiregulin, betacellulin, TGF-α, fibroblast growth factor 2, placental growth factor (PLGF), and tenascin C were increased in rheumatoid arthritis patients. Furthermore, local blockades of these growth factors suppressed the development of cytokine-induced arthritis in mice by inhibiting chemokine and IL-6 expressions. We found that epiregulin expression was early and followed by the induction of other growth factors at different sites of the joints. The same growth factors then regulated the expression of epiregulin at later time points of the arthritis. These growth factors were increased in patients suffering from multiple sclerosis (MS) and also played a role in the development of an MS model, experimental autoimmune encephalomyelitis. The results suggest that the temporal expression of growth factors is involved in the inflammation development seen in several diseases, including rheumatoid arthritis and MS. Therefore, various growth factor pathways might be good therapeutic targets for various inflammatory diseases.
Sterile DJH Rearrangements Reveal that Distance Between Gene Segments on the Human Ig H Chain Locus Influences Their Ability To Rearrange
Authors: Hansen Tina Østergaard , Lange Anders Blaabjerg , Barington Torben
Published: January 2015

Rearrangement of the Ig locus occurs in two steps. First, a JH gene is rearranged to a D gene followed by a VH gene rearranging to the DJH rearrangement. By next generation sequencing, we analyzed 9969 unique DJH rearrangements and 5919 unique VHDJH rearrangements obtained from peripheral blood B cells from 110 healthy adult donors. We found that DJH rearrangements and nonproductive VHDJH rearrangements share many features but differ significantly in their use of D genes and propensity for somatic hypermutation. In D to JH gene rearrangements, the D genes proximal to the JH locus are used more frequently than JH locus distal D genes, whereas VH locus proximal D genes were observed more frequently in nonproductive VHDJH rearrangements. We further demonstrate that the distance between VH, D, and JH gene segments influence their ability to rearrange within the human Ig locus.
The Human IL-23 Receptor rs11209026 A Allele Promotes the Expression of a Soluble IL-23R–Encoding mRNA Species
Authors: Yu Raymond Y. , Brazaitis Jonathan , Gallagher Grant
Published: January 2015

The human IL23R gene single nucleotide polymorphism rs11209026 A allele confers protection against inflammatory diseases. However, although this difference has been associated with reductions in IL-23–induced IL-17A production and STAT3 phosphorylation, the molecular mechanism underlying these changes remains undefined. Th17 cell maturation depends on IL-23 signaling. Multiple splice forms of the human IL23R transcript exist, and one, Δ9, encodes a soluble form of the receptor. In this study, we asked whether this protective allele was associated with mRNA splicing. Using mini-gene constructs and competitive oligonucleotide binding, we showed that the A allele alters IL-23R α-chain mRNA splicing and favors exon 9 skipping by reducing the binding of the splicing enhancer SF2. This enhances expression of the Δ9 mRNA and consequently diminishes IL-23 signaling. Thus, the presence of the A allele increases expression of the soluble form of IL23R mRNA (which then functions as a decoy receptor) and lowers the ability to develop a Th17 phenotype upon IL-23 stimulation. We further showed that antisense oligonucleotides targeting the SF2 binding site could efficiently induce exon 9 skipping in the presence of the G allele, and thereby replicate the effect of the A allele. Antisense oligonucleotide treatment caused dose-responsive induction of the IL23RΔ9 mRNA and interfered with in vitro differentiation of human Th17 cells, reducing their expression of the signature Th17 cytokines IL-17A and IL-17F. This may represent a novel approach to therapy of Th17-mediated diseases by elevating soluble IL-23R while simultaneously reducing the remaining cell surface receptor density.
Homeodomain-Interacting Protein Kinase 2, a Novel Autoimmune Regulator Interaction Partner, Modulates Promiscuous Gene Expression in Medullary Thymic Epithelial Cells
Authors: Rattay Kristin , Claude Janine , Rezavandy Esmail , Matt Sonja , Hofmann Thomas G. , Kyewski Bruno , Derbinski Jens
Published: January 2015

Promiscuous expression of a plethora of tissue-restricted Ags (TRAs) by medullary thymic epithelial cells (mTECs) plays an essential role in T cell tolerance. Although the cellular mechanisms by which promiscuous gene expression (pGE) imposes T cell tolerance have been well characterized, the underlying molecular mechanisms remain poorly understood. The autoimmune regulator (AIRE) is to date the only validated molecule known to regulate pGE. AIRE is part of higher-order multiprotein complexes, which promote transcription, elongation, and splicing of a wide range of target genes. How AIRE and its partners mediate these various effects at the molecular level is still largely unclear. Using a yeast two-hybrid screen, we searched for novel AIRE-interacting proteins and identified the homeodomain-interacting protein kinase 2 (HIPK2) as a novel partner. HIPK2 partially colocalized with AIRE in nuclear bodies upon cotransfection and in human mTECs in situ. Moreover, HIPK2 phosphorylated AIRE in vitro and suppressed the coactivator activity of AIRE in a kinase-dependent manner. To evaluate the role of Hipk2 in modulating the function of AIRE in vivo, we compared whole-genome gene signatures of purified mTEC subsets from TEC-specific Hipk2 knockout mice with control mice and identified a small set of differentially expressed genes. Unexpectedly, most differentially expressed genes were confined to the CD80lo mTEC subset and preferentially included AIRE-independent TRAs. Thus, although it modulates gene expression in mTECs and in addition affects the size of the medullary compartment, TEC-specific HIPK2 deletion only mildly affects AIRE-directed pGE in vivo.
Population resources of an endangered species Salix lapponum L. in Polesie Lubelskie Region (eastern Poland)
Authors: Pogorzelec Magdalena , Banach-Albińska Barbara , Serafin Artur , Szczurowska Agnieszka
Published: January 2015

This research, carried out in the years 2011–2013, aimed to evaluate Salix lapponum stands in the peat bogs of Polesie Lubelskie Region as well as to determine the condition of the population and the changes that have taken place since the 1950’s. An inventory carried out in 25 stands of S. lapponum known from the literature shows that the number of its stands has decreased by 80% in Polesie Lubelskie Region. In all the confirmed locations, a decrease in population numbers was also found in relation to the data known from the literature since the 1950’s. In the majority of the population locations that were considered to be extinct, there were no significant changes in habitat conditions, and ecological succession and changes in hydrological conditions could have been the cause of habitat changes only at a few sites. In the light of the study, the preservation of the S. lapponum population in Polesie Lubelskie seems to be impossible if appropriate active conservation measures are not taken immediately. Because area-based conservation, which covers most of the habitats of the studied species, does not bring the expected results, the possibility of ex situ conservation and enlargement of the populations existing in the natural environment in peat bog ecosystems in Polesie should be explored.
Changes in spring wheat (Triticum aestivum ssp. vulgare L.) and persian clover (Trifolium resupinatum L.) biomass under the influence of plant competition and density
Authors: Aniela Maria , Myśliwiec Monika
Published: January 2015

The influence of sowing method and plant density on the biomass of spring wheat and Persian clover was evaluated. In a pot experiment conducted in three series during the years 2010–2012, plants were cultivated as mixed and pure crop at higher (consistent with agronomic recommendations) and lower density, decreased by 20% compared to it. Dry mass accumulation tests for both species were conducted during the following wheat growth stages (BBCH): leaf development (12–14), tillering (21–23), stem elongation (31–32), inflorescence development (54–56), and ripening (87–89). Based on the results obtained, the biomass growth rate for both species in question was also determined. It was shown that the mass of shoots of spring wheat cultivated as mixed crop was lower than that of wheat shoots grown as pure crop during the stem elongation and ripening stages. Mixed sowing limited aboveground accumulation in the heads and grain the most and in the stems the least. During the leaf development and stem elongation stages, the wheat presented a more pronounced response to the presence of clover expressed by biomass decrease in case of the treatment with lower plant density and during ripening in the treatment with recommended plant density. In case of both sowing methods and plant densities, the mass of wheat roots was similar. Biomass accumulation in Persian clover shoots and roots in mixed sowing was lower than in pure crop during the entire growing period. The wheat limited biomass accumulation of Persian clover in inflorescences the strongest and in the roots the least. The spring wheat growth rate in both sowing methods was similar as opposed to Persian clover in the case of which a decrease in the growth rate was observed in the mixed crop during the generative development period.
miR-128 regulates neuronal migration, outgrowth and intrinsic excitability via the intellectual disability gene Phf6
Authors: Franzoni Eleonora , Booker Sam A , Parthasarathy Srinivas , Rehfeld Frederick , Grosser Sabine , Srivatsa Swathi , Fuchs Heiko R , Tarabykin Victor , Vida Imre , Wulczyn F Gregory
Published: January 2015

miR-128, a brain-enriched microRNA, has been implicated in the control of neurogenesis and synaptogenesis but its potential roles in intervening processes have not been addressed. We show that post-transcriptional mechanisms restrict miR-128 accumulation to post-mitotic neurons during mouse corticogenesis and in adult stem cell niches. Whereas premature miR-128 expression in progenitors for upper layer neurons leads to impaired neuronal migration and inappropriate branching, sponge-mediated inhibition results in overmigration. Within the upper layers, premature miR-128 expression reduces the complexity of dendritic arborization, associated with altered electrophysiological properties. We show that Phf6, a gene mutated in the cognitive disorder Börjeson-Forssman-Lehmann syndrome, is an important regulatory target for miR-128. Restoring PHF6 expression counteracts the deleterious effect of miR-128 on neuronal migration, outgrowth and intrinsic physiological properties. Our results place miR-128 upstream of PHF6 in a pathway vital for cortical lamination as well as for the development of neuronal morphology and intrinsic excitability.